From e0ab949f152a7f070fbf7b56d9caa4206b140190 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 8 Sep 2020 15:07:49 +0200 Subject: [PATCH 01/32] gpio: mockup: fix resource leak in error path If the module init function fails after creating the debugs directory, it's never removed. Add proper cleanup calls to avoid this resource leak. Fixes: 9202ba2397d1 ("gpio: mockup: implement event injecting over debugfs") Cc: Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index bc345185db26..1652897fdf90 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -552,6 +552,7 @@ static int __init gpio_mockup_init(void) err = platform_driver_register(&gpio_mockup_driver); if (err) { gpio_mockup_err("error registering platform driver\n"); + debugfs_remove_recursive(gpio_mockup_dbg_dir); return err; } @@ -582,6 +583,7 @@ static int __init gpio_mockup_init(void) gpio_mockup_err("error registering device"); platform_driver_unregister(&gpio_mockup_driver); gpio_mockup_unregister_pdevs(); + debugfs_remove_recursive(gpio_mockup_dbg_dir); return PTR_ERR(pdev); } From 3795d7cc4fe13200dae9fade93441b4d5f123b74 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Wed, 30 Sep 2020 09:42:11 +0200 Subject: [PATCH 02/32] gpio: mpc8xxx: simplify ls1028a/ls1088a support Some Layerscape/QoriQ SoCs have input buffers which needs to be enabled first. This was done in two different ways in the driver. Unify it. This was tested on a LS1028A SoC. Signed-off-by: Michael Walle Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-mpc8xxx.c | 45 ++++++++++--------------------------- 1 file changed, 12 insertions(+), 33 deletions(-) diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c index 1e866524a4bd..6dfca83bcd90 100644 --- a/drivers/gpio/gpio-mpc8xxx.c +++ b/drivers/gpio/gpio-mpc8xxx.c @@ -47,27 +47,6 @@ struct mpc8xxx_gpio_chip { unsigned int irqn; }; -/* The GPIO Input Buffer Enable register(GPIO_IBE) is used to - * control the input enable of each individual GPIO port. - * When an individual GPIO port’s direction is set to - * input (GPIO_GPDIR[DRn=0]), the associated input enable must be - * set (GPIOxGPIE[IEn]=1) to propagate the port value to the GPIO - * Data Register. - */ -static int ls1028a_gpio_dir_in_init(struct gpio_chip *gc) -{ - unsigned long flags; - struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc); - - spin_lock_irqsave(&gc->bgpio_lock, flags); - - gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff); - - spin_unlock_irqrestore(&gc->bgpio_lock, flags); - - return 0; -} - /* * This hardware has a big endian bit assignment such that GPIO line 0 is * connected to bit 31, line 1 to bit 30 ... line 31 to bit 0. @@ -283,7 +262,6 @@ static const struct irq_domain_ops mpc8xxx_gpio_irq_ops = { }; struct mpc8xxx_gpio_devtype { - int (*gpio_dir_in_init)(struct gpio_chip *chip); int (*gpio_dir_out)(struct gpio_chip *, unsigned int, int); int (*gpio_get)(struct gpio_chip *, unsigned int); int (*irq_set_type)(struct irq_data *, unsigned int); @@ -294,11 +272,6 @@ static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = { .irq_set_type = mpc512x_irq_set_type, }; -static const struct mpc8xxx_gpio_devtype ls1028a_gpio_devtype = { - .gpio_dir_in_init = ls1028a_gpio_dir_in_init, - .irq_set_type = mpc8xxx_irq_set_type, -}; - static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = { .gpio_dir_out = mpc5125_gpio_dir_out, .irq_set_type = mpc512x_irq_set_type, @@ -319,8 +292,8 @@ static const struct of_device_id mpc8xxx_gpio_ids[] = { { .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, }, { .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, }, { .compatible = "fsl,pq3-gpio", }, - { .compatible = "fsl,ls1028a-gpio", .data = &ls1028a_gpio_devtype, }, - { .compatible = "fsl,ls1088a-gpio", .data = &ls1028a_gpio_devtype, }, + { .compatible = "fsl,ls1028a-gpio", }, + { .compatible = "fsl,ls1088a-gpio", }, { .compatible = "fsl,qoriq-gpio", }, {} }; @@ -389,7 +362,16 @@ static int mpc8xxx_probe(struct platform_device *pdev) gc->to_irq = mpc8xxx_gpio_to_irq; - if (of_device_is_compatible(np, "fsl,qoriq-gpio")) + /* + * The GPIO Input Buffer Enable register(GPIO_IBE) is used to control + * the input enable of each individual GPIO port. When an individual + * GPIO port’s direction is set to input (GPIO_GPDIR[DRn=0]), the + * associated input enable must be set (GPIOxGPIE[IEn]=1) to propagate + * the port value to the GPIO Data Register. + */ + if (of_device_is_compatible(np, "fsl,qoriq-gpio") || + of_device_is_compatible(np, "fsl,ls1028a-gpio") || + of_device_is_compatible(np, "fsl,ls1088a-gpio")) gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff); ret = gpiochip_add_data(gc, mpc8xxx_gc); @@ -411,9 +393,6 @@ static int mpc8xxx_probe(struct platform_device *pdev) /* ack and mask all irqs */ gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff); gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0); - /* enable input buffer */ - if (devtype->gpio_dir_in_init) - devtype->gpio_dir_in_init(gc); ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn, mpc8xxx_gpio_irq_cascade, From 0fd16012adc0a994a7ce980a78e22e4de6220778 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:09:55 +0200 Subject: [PATCH 03/32] lib: string_helpers: provide kfree_strarray() There's a common pattern of dynamically allocating an array of char pointers and then also dynamically allocating each string in this array. Provide a helper for freeing such a string array with one call. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- include/linux/string_helpers.h | 2 ++ lib/string_helpers.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h index 86f150c2a6b6..fa06dcdc481e 100644 --- a/include/linux/string_helpers.h +++ b/include/linux/string_helpers.h @@ -94,4 +94,6 @@ char *kstrdup_quotable(const char *src, gfp_t gfp); char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp); char *kstrdup_quotable_file(struct file *file, gfp_t gfp); +void kfree_strarray(char **array, size_t n); + #endif diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 963050c0283e..7f2d5fbaf243 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -649,3 +649,26 @@ char *kstrdup_quotable_file(struct file *file, gfp_t gfp) return pathname; } EXPORT_SYMBOL_GPL(kstrdup_quotable_file); + +/** + * kfree_strarray - free a number of dynamically allocated strings contained + * in an array and the array itself + * + * @array: Dynamically allocated array of strings to free. + * @n: Number of strings (starting from the beginning of the array) to free. + * + * Passing a non-NULL @array and @n == 0 as well as NULL @array are valid + * use-cases. If @array is NULL, the function does nothing. + */ +void kfree_strarray(char **array, size_t n) +{ + unsigned int i; + + if (!array) + return; + + for (i = 0; i < n; i++) + kfree(array[i]); + kfree(array); +} +EXPORT_SYMBOL_GPL(kfree_strarray); From 2fd1abe99e5fbc6091b2015577b43e6f365e35bb Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:09:56 +0200 Subject: [PATCH 04/32] Documentation: gpio: add documentation for gpio-mockup There's some documentation for gpio-mockup's debugfs interface in the driver's source but it's not much. Add proper documentation for this testing module. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- .../admin-guide/gpio/gpio-mockup.rst | 50 +++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 Documentation/admin-guide/gpio/gpio-mockup.rst diff --git a/Documentation/admin-guide/gpio/gpio-mockup.rst b/Documentation/admin-guide/gpio/gpio-mockup.rst new file mode 100644 index 000000000000..9fa1618b3adc --- /dev/null +++ b/Documentation/admin-guide/gpio/gpio-mockup.rst @@ -0,0 +1,50 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +GPIO Testing Driver +=================== + +The GPIO Testing Driver (gpio-mockup) provides a way to create simulated GPIO +chips for testing purposes. The lines exposed by these chips can be accessed +using the standard GPIO character device interface as well as manipulated +using the dedicated debugfs directory structure. + +Creating simulated chips using module params +-------------------------------------------- + +When loading the gpio-mockup driver a number of parameters can be passed to the +module. + + gpio_mockup_ranges + + This parameter takes an argument in the form of an array of integer + pairs. Each pair defines the base GPIO number (if any) and the number + of lines exposed by the chip. If the base GPIO is -1, the gpiolib + will assign it automatically. + + Example: gpio_mockup_ranges=-1,8,-1,16,405,4 + + The line above creates three chips. The first one will expose 8 lines, + the second 16 and the third 4. The base GPIO for the third chip is set + to 405 while for two first chips it will be assigned automatically. + + gpio_named_lines + + This parameter doesn't take any arguments. It lets the driver know that + GPIO lines exposed by it should be named. + + The name format is: gpio-mockup-X-Y where X is mockup chip's ID + and Y is the line offset. + +Manipulating simulated lines +---------------------------- + +Each mockup chip creates its own subdirectory in /sys/kernel/debug/gpio-mockup/. +The directory is named after the chip's label. A symlink is also created, named +after the chip's name, which points to the label directory. + +Inside each subdirectory, there's a separate attribute for each GPIO line. The +name of the attribute represents the line's offset in the chip. + +Reading from a line attribute returns the current value. Writing to it (0 or 1) +changes the configuration of the simulated pull-up/pull-down resistor +(1 - pull-up, 0 - pull-down). From 94502ba9a47c2bfbd2e4d4d683392b409e9c31bb Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:09:57 +0200 Subject: [PATCH 05/32] gpio: mockup: drop unneeded includes This module doesn't need gpio/consumer.h - it's a provider. It also doesn't use any symbols from init.h so let's remove both includes. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 1652897fdf90..c5092773afd8 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -8,9 +8,7 @@ */ #include -#include #include -#include #include #include #include From 25f0006603e4a5e9a2dbdbbe1783803fa6b1e239 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:09:58 +0200 Subject: [PATCH 06/32] gpio: mockup: use KBUILD_MODNAME Drop the definition for the driver name. Let's use KBUILD_MODNAME for the log format and use the "gpio-mockup" value directly in the only place where it's relevant: in the name of the device. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index c5092773afd8..90a1d6c2775f 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -21,7 +21,6 @@ #include "gpiolib.h" -#define GPIO_MOCKUP_NAME "gpio-mockup" #define GPIO_MOCKUP_MAX_GC 10 /* * We're storing two values per chip: the GPIO base and the number @@ -31,7 +30,7 @@ /* Maximum of three properties + the sentinel. */ #define GPIO_MOCKUP_MAX_PROP 4 -#define gpio_mockup_err(...) pr_err(GPIO_MOCKUP_NAME ": " __VA_ARGS__) +#define gpio_mockup_err(...) pr_err(KBUILD_MODNAME ": " __VA_ARGS__) /* * struct gpio_pin_status - structure describing a GPIO status @@ -500,7 +499,7 @@ static int gpio_mockup_probe(struct platform_device *pdev) static struct platform_driver gpio_mockup_driver = { .driver = { - .name = GPIO_MOCKUP_NAME, + .name = "gpio-mockup", }, .probe = gpio_mockup_probe, }; @@ -572,7 +571,7 @@ static int __init gpio_mockup_init(void) properties[prop++] = PROPERTY_ENTRY_BOOL( "named-gpio-lines"); - pdevinfo.name = GPIO_MOCKUP_NAME; + pdevinfo.name = "gpio-mockup"; pdevinfo.id = i; pdevinfo.properties = properties; From 56f6cb35e2749156c779d0cc7ae2a68305666c14 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:09:59 +0200 Subject: [PATCH 07/32] gpio: mockup: use pr_fmt() We don't need a custom logging helper. Let's use the standard pr_fmt() macro which allows us to use all pr_*() routines with custom format. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 90a1d6c2775f..c2b2f7d5ff34 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -7,6 +7,8 @@ * Copyright (C) 2017 Bartosz Golaszewski */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -30,8 +32,6 @@ /* Maximum of three properties + the sentinel. */ #define GPIO_MOCKUP_MAX_PROP 4 -#define gpio_mockup_err(...) pr_err(KBUILD_MODNAME ": " __VA_ARGS__) - /* * struct gpio_pin_status - structure describing a GPIO status * @dir: Configures direction of gpio as "in" or "out" @@ -548,7 +548,7 @@ static int __init gpio_mockup_init(void) err = platform_driver_register(&gpio_mockup_driver); if (err) { - gpio_mockup_err("error registering platform driver\n"); + pr_err("error registering platform driver\n"); debugfs_remove_recursive(gpio_mockup_dbg_dir); return err; } @@ -577,7 +577,7 @@ static int __init gpio_mockup_init(void) pdev = platform_device_register_full(&pdevinfo); if (IS_ERR(pdev)) { - gpio_mockup_err("error registering device"); + pr_err("error registering device"); platform_driver_unregister(&gpio_mockup_driver); gpio_mockup_unregister_pdevs(); debugfs_remove_recursive(gpio_mockup_dbg_dir); From 66f222ef45f3d55121fd69bd5d03e74c0d1ff1e5 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:10:00 +0200 Subject: [PATCH 08/32] gpio: mockup: remove unneeded return statement There's a return; at the end of a void function. This is not needed so remove it. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index c2b2f7d5ff34..de778b52f355 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -372,8 +372,6 @@ static void gpio_mockup_debugfs_setup(struct device *dev, debugfs_create_file(name, 0200, chip->dbg_dir, priv, &gpio_mockup_debugfs_ops); } - - return; } static int gpio_mockup_name_lines(struct device *dev, From 383bb2de4d494ec0a62a1ab2cd8438c04e9100bd Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:10:01 +0200 Subject: [PATCH 09/32] gpio: mockup: increase the number of supported device properties The driver actually supports 4 properties but we only ever set up up to three. This will change however in upcoming patches so increase the number of really (as in: the number the property array can hold) supported properties to 4. Reported-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index de778b52f355..856ba5da1e8c 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -29,8 +29,8 @@ * of GPIO lines. */ #define GPIO_MOCKUP_MAX_RANGES (GPIO_MOCKUP_MAX_GC * 2) -/* Maximum of three properties + the sentinel. */ -#define GPIO_MOCKUP_MAX_PROP 4 +/* Maximum of four properties + the sentinel. */ +#define GPIO_MOCKUP_MAX_PROP 5 /* * struct gpio_pin_status - structure describing a GPIO status From 148c2560c55b5d4a46849324498f4f0b14a8243d Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:10:02 +0200 Subject: [PATCH 10/32] gpio: mockup: pass the chip label as device property While we do check the "chip-name" property in probe(), we never actually use it. Let's pass the chip label to the driver using device properties as we'll want to allow users to define their own once dynamically created chips are supported. The property is renamed to "chip-label" to not cause any confusion with the actual chip name which is of the form: "gpiochipX". If the "chip-label" property is missing, let's do what most devices in drivers/gpio/ do and use dev_name(). Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 856ba5da1e8c..1466f480aacd 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -429,21 +429,14 @@ static int gpio_mockup_probe(struct platform_device *pdev) if (rv) return rv; - rv = device_property_read_string(dev, "chip-name", &name); + rv = device_property_read_string(dev, "chip-label", &name); if (rv) - name = NULL; + name = dev_name(dev); chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; - if (!name) { - name = devm_kasprintf(dev, GFP_KERNEL, - "%s-%c", pdev->name, pdev->id + 'A'); - if (!name) - return -ENOMEM; - } - mutex_init(&chip->lock); gc = &chip->gc; @@ -523,6 +516,7 @@ static int __init gpio_mockup_init(void) int i, prop, num_chips, err = 0, base; struct platform_device_info pdevinfo; struct platform_device *pdev; + char chip_label[32]; u16 ngpio; if ((gpio_mockup_num_ranges < 2) || @@ -556,6 +550,11 @@ static int __init gpio_mockup_init(void) memset(&pdevinfo, 0, sizeof(pdevinfo)); prop = 0; + snprintf(chip_label, sizeof(chip_label), + "gpio-mockup-%c", i + 'A'); + properties[prop++] = PROPERTY_ENTRY_STRING("chip-label", + chip_label); + base = gpio_mockup_range_base(i); if (base >= 0) properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", From 582be05ea42aca26cb640d1a82d7ec860e577fb5 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:10:03 +0200 Subject: [PATCH 11/32] gpio: mockup: use the generic 'gpio-line-names' property GPIO line names are currently created by the driver from the chip label. We'll want to support custom formats for line names (for instance: to name all lines the same) for user-space tests so create them in the module init function and pass them to the driver using the standard 'gpio-line-names' property. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 70 +++++++++++++++++++++----------------- 1 file changed, 38 insertions(+), 32 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 1466f480aacd..2d865b530fe9 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include "gpiolib.h" @@ -374,29 +375,6 @@ static void gpio_mockup_debugfs_setup(struct device *dev, } } -static int gpio_mockup_name_lines(struct device *dev, - struct gpio_mockup_chip *chip) -{ - struct gpio_chip *gc = &chip->gc; - char **names; - int i; - - names = devm_kcalloc(dev, gc->ngpio, sizeof(char *), GFP_KERNEL); - if (!names) - return -ENOMEM; - - for (i = 0; i < gc->ngpio; i++) { - names[i] = devm_kasprintf(dev, GFP_KERNEL, - "%s-%d", gc->label, i); - if (!names[i]) - return -ENOMEM; - } - - gc->names = (const char *const *)names; - - return 0; -} - static void gpio_mockup_dispose_mappings(void *data) { struct gpio_mockup_chip *chip = data; @@ -464,12 +442,6 @@ static int gpio_mockup_probe(struct platform_device *pdev) for (i = 0; i < gc->ngpio; i++) chip->lines[i].dir = GPIO_LINE_DIRECTION_IN; - if (device_property_read_bool(dev, "named-gpio-lines")) { - rv = gpio_mockup_name_lines(dev, chip); - if (rv) - return rv; - } - chip->irq_sim_domain = devm_irq_domain_create_sim(dev, NULL, gc->ngpio); if (IS_ERR(chip->irq_sim_domain)) @@ -510,6 +482,27 @@ static void gpio_mockup_unregister_pdevs(void) } } +static __init char **gpio_mockup_make_line_names(const char *label, + unsigned int num_lines) +{ + unsigned int i; + char **names; + + names = kcalloc(num_lines + 1, sizeof(char *), GFP_KERNEL); + if (!names) + return NULL; + + for (i = 0; i < num_lines; i++) { + names[i] = kasprintf(GFP_KERNEL, "%s-%u", label, i); + if (!names[i]) { + kfree_strarray(names, i); + return NULL; + } + } + + return names; +} + static int __init gpio_mockup_init(void) { struct property_entry properties[GPIO_MOCKUP_MAX_PROP]; @@ -517,6 +510,7 @@ static int __init gpio_mockup_init(void) struct platform_device_info pdevinfo; struct platform_device *pdev; char chip_label[32]; + char **line_names; u16 ngpio; if ((gpio_mockup_num_ranges < 2) || @@ -549,6 +543,7 @@ static int __init gpio_mockup_init(void) memset(properties, 0, sizeof(properties)); memset(&pdevinfo, 0, sizeof(pdevinfo)); prop = 0; + line_names = NULL; snprintf(chip_label, sizeof(chip_label), "gpio-mockup-%c", i + 'A'); @@ -564,15 +559,26 @@ static int __init gpio_mockup_init(void) : gpio_mockup_range_ngpio(i) - base; properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio); - if (gpio_mockup_named_lines) - properties[prop++] = PROPERTY_ENTRY_BOOL( - "named-gpio-lines"); + if (gpio_mockup_named_lines) { + line_names = gpio_mockup_make_line_names(chip_label, + ngpio); + if (!line_names) { + platform_driver_unregister(&gpio_mockup_driver); + gpio_mockup_unregister_pdevs(); + return -ENOMEM; + } + + properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( + "gpio-line-names", + line_names, ngpio); + } pdevinfo.name = "gpio-mockup"; pdevinfo.id = i; pdevinfo.properties = properties; pdev = platform_device_register_full(&pdevinfo); + kfree_strarray(line_names, ngpio); if (IS_ERR(pdev)) { pr_err("error registering device"); platform_driver_unregister(&gpio_mockup_driver); From 42e9acc679105208e001a2911c0241d968ab68e5 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Tue, 29 Sep 2020 12:10:04 +0200 Subject: [PATCH 12/32] gpio: mockup: refactor the module init function Let's move the code preparing the device properties into a separate routine. This has the advantage of simplifying the error handling and makes the indentation less deep. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko --- drivers/gpio/gpio-mockup.c | 96 +++++++++++++++++++------------------- 1 file changed, 49 insertions(+), 47 deletions(-) diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c index 2d865b530fe9..67ed4f238d43 100644 --- a/drivers/gpio/gpio-mockup.c +++ b/drivers/gpio/gpio-mockup.c @@ -503,16 +503,59 @@ static __init char **gpio_mockup_make_line_names(const char *label, return names; } -static int __init gpio_mockup_init(void) +static int __init gpio_mockup_register_chip(int idx) { struct property_entry properties[GPIO_MOCKUP_MAX_PROP]; - int i, prop, num_chips, err = 0, base; struct platform_device_info pdevinfo; struct platform_device *pdev; + char **line_names = NULL; char chip_label[32]; - char **line_names; + int prop = 0, base; u16 ngpio; + memset(properties, 0, sizeof(properties)); + memset(&pdevinfo, 0, sizeof(pdevinfo)); + + snprintf(chip_label, sizeof(chip_label), "gpio-mockup-%c", idx + 'A'); + properties[prop++] = PROPERTY_ENTRY_STRING("chip-label", chip_label); + + base = gpio_mockup_range_base(idx); + if (base >= 0) + properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", base); + + ngpio = base < 0 ? gpio_mockup_range_ngpio(idx) + : gpio_mockup_range_ngpio(idx) - base; + properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio); + + if (gpio_mockup_named_lines) { + line_names = gpio_mockup_make_line_names(chip_label, ngpio); + if (!line_names) + return -ENOMEM; + + properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( + "gpio-line-names", line_names, ngpio); + } + + pdevinfo.name = "gpio-mockup"; + pdevinfo.id = idx; + pdevinfo.properties = properties; + + pdev = platform_device_register_full(&pdevinfo); + kfree_strarray(line_names, ngpio); + if (IS_ERR(pdev)) { + pr_err("error registering device"); + return PTR_ERR(pdev); + } + + gpio_mockup_pdevs[idx] = pdev; + + return 0; +} + +static int __init gpio_mockup_init(void) +{ + int i, num_chips, err; + if ((gpio_mockup_num_ranges < 2) || (gpio_mockup_num_ranges % 2) || (gpio_mockup_num_ranges > GPIO_MOCKUP_MAX_RANGES)) @@ -540,54 +583,13 @@ static int __init gpio_mockup_init(void) } for (i = 0; i < num_chips; i++) { - memset(properties, 0, sizeof(properties)); - memset(&pdevinfo, 0, sizeof(pdevinfo)); - prop = 0; - line_names = NULL; - - snprintf(chip_label, sizeof(chip_label), - "gpio-mockup-%c", i + 'A'); - properties[prop++] = PROPERTY_ENTRY_STRING("chip-label", - chip_label); - - base = gpio_mockup_range_base(i); - if (base >= 0) - properties[prop++] = PROPERTY_ENTRY_U32("gpio-base", - base); - - ngpio = base < 0 ? gpio_mockup_range_ngpio(i) - : gpio_mockup_range_ngpio(i) - base; - properties[prop++] = PROPERTY_ENTRY_U16("nr-gpios", ngpio); - - if (gpio_mockup_named_lines) { - line_names = gpio_mockup_make_line_names(chip_label, - ngpio); - if (!line_names) { - platform_driver_unregister(&gpio_mockup_driver); - gpio_mockup_unregister_pdevs(); - return -ENOMEM; - } - - properties[prop++] = PROPERTY_ENTRY_STRING_ARRAY_LEN( - "gpio-line-names", - line_names, ngpio); - } - - pdevinfo.name = "gpio-mockup"; - pdevinfo.id = i; - pdevinfo.properties = properties; - - pdev = platform_device_register_full(&pdevinfo); - kfree_strarray(line_names, ngpio); - if (IS_ERR(pdev)) { - pr_err("error registering device"); + err = gpio_mockup_register_chip(i); + if (err) { platform_driver_unregister(&gpio_mockup_driver); gpio_mockup_unregister_pdevs(); debugfs_remove_recursive(gpio_mockup_dbg_dir); - return PTR_ERR(pdev); + return err; } - - gpio_mockup_pdevs[i] = pdev; } return 0; From 0dc11e3ad353e19b1a119e3146c69c0930ecae5f Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:48 +0800 Subject: [PATCH 13/32] gpiolib: cdev: gpio_desc_to_lineinfo() should set info offset Set the value of the line info offset in gpio_desc_to_lineinfo(), rather than relying on it being passed in the info. This makes the function behave as you would expect from the name - it generates the line info corresponding to a given GPIO desc. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index e6c9b78adfc2..81ce2020f17b 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -752,6 +752,8 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, bool ok_for_pinctrl; unsigned long flags; + info->line_offset = gpio_chip_hwgpio(desc); + /* * This function takes a mutex so we must check this before taking * the spinlock. @@ -933,7 +935,6 @@ static int lineinfo_changed_notify(struct notifier_block *nb, return NOTIFY_DONE; memset(&chg, 0, sizeof(chg)); - chg.info.line_offset = gpio_chip_hwgpio(desc); chg.event_type = action; chg.timestamp = ktime_get_ns(); gpio_desc_to_lineinfo(desc, &chg.info); From 69e4e1368803266d0e06dba86868f64f7b277cde Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:49 +0800 Subject: [PATCH 14/32] gpiolib: cdev: replace strncpy() with strscpy() Replace usage of strncpy() with strscpy() to remove -Wstringop-truncation warnings. The structures being populated are zeroed, to prevent stack leakage as they are returned to userspace, so strscpy() performs the equivalent function without the warnings. Reported-by: kernel test robot Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 81ce2020f17b..86679397d09c 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -752,6 +752,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, bool ok_for_pinctrl; unsigned long flags; + memset(info, 0, sizeof(*info)); info->line_offset = gpio_chip_hwgpio(desc); /* @@ -766,19 +767,11 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, spin_lock_irqsave(&gpio_lock, flags); - if (desc->name) { - strncpy(info->name, desc->name, sizeof(info->name)); - info->name[sizeof(info->name) - 1] = '\0'; - } else { - info->name[0] = '\0'; - } + if (desc->name) + strscpy(info->name, desc->name, sizeof(info->name)); - if (desc->label) { - strncpy(info->consumer, desc->label, sizeof(info->consumer)); - info->consumer[sizeof(info->consumer) - 1] = '\0'; - } else { - info->consumer[0] = '\0'; - } + if (desc->label) + strscpy(info->consumer, desc->label, sizeof(info->consumer)); /* * Userspace only need to know that the kernel is using this GPIO so @@ -842,12 +835,10 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) memset(&chipinfo, 0, sizeof(chipinfo)); - strncpy(chipinfo.name, dev_name(&gdev->dev), + strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); - chipinfo.name[sizeof(chipinfo.name)-1] = '\0'; - strncpy(chipinfo.label, gdev->label, + strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); - chipinfo.label[sizeof(chipinfo.label)-1] = '\0'; chipinfo.lines = gdev->ngpio; if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) return -EFAULT; From 539430fbbcc4a8d02451c77fff1ecd1f3b5f8abf Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:50 +0800 Subject: [PATCH 15/32] gpio: uapi: define GPIO_MAX_NAME_SIZE for array sizes Replace constant array sizes with a macro constant to clarify the source of array sizes, provide a place to document any constraints on the size, and to simplify array sizing in userspace if constructing structs from their composite fields. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- include/uapi/linux/gpio.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 9c27cecf406f..285cc10355b2 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -14,6 +14,11 @@ #include #include +/* + * The maximum size of name and label arrays. + */ +#define GPIO_MAX_NAME_SIZE 32 + /** * struct gpiochip_info - Information about a certain GPIO chip * @name: the Linux kernel name of this GPIO chip @@ -22,8 +27,8 @@ * @lines: number of GPIO lines on this chip */ struct gpiochip_info { - char name[32]; - char label[32]; + char name[GPIO_MAX_NAME_SIZE]; + char label[GPIO_MAX_NAME_SIZE]; __u32 lines; }; @@ -52,8 +57,8 @@ struct gpiochip_info { struct gpioline_info { __u32 line_offset; __u32 flags; - char name[32]; - char consumer[32]; + char name[GPIO_MAX_NAME_SIZE]; + char consumer[GPIO_MAX_NAME_SIZE]; }; /* Maximum number of requested handles */ @@ -123,7 +128,7 @@ struct gpiohandle_request { __u32 lineoffsets[GPIOHANDLES_MAX]; __u32 flags; __u8 default_values[GPIOHANDLES_MAX]; - char consumer_label[32]; + char consumer_label[GPIO_MAX_NAME_SIZE]; __u32 lines; int fd; }; @@ -182,7 +187,7 @@ struct gpioevent_request { __u32 lineoffset; __u32 handleflags; __u32 eventflags; - char consumer_label[32]; + char consumer_label[GPIO_MAX_NAME_SIZE]; int fd; }; From b53911aa872db462be2e5f1dd611b25c4c2e663b Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:51 +0800 Subject: [PATCH 16/32] gpio: uapi: define uAPI v2 Add a new version of the uAPI to address existing 32/64-bit alignment issues, add support for debounce and event sequence numbers, allow requested lines with different configurations, and provide some future proofing by adding padding reserved for future use. The alignment issue relates to the gpioevent_data, which packs to different sizes on 32-bit and 64-bit platforms. That creates problems for 32-bit apps running on 64-bit kernels. uAPI v2 addresses that particular issue, and the problem more generally, by adding pad fields that explicitly pad structs out to 64-bit boundaries, so they will pack to the same size now, and even if some of the reserved padding is used for __u64 fields in the future. The new structs have been analysed with pahole to ensure that they are sized as expected and contain no implicit padding. The lack of future proofing in v1 makes it impossible to, for example, add the debounce feature that is included in v2. The future proofing is addressed by providing configurable attributes in line config and reserved padding in all structs for future features. Specifically, the line request, config, info, info_changed and event structs receive updated versions and new ioctls. As the majority of the structs and ioctls were being replaced, it is opportune to rework some of the other aspects of the uAPI: v1 has three different flags fields, each with their own separate bit definitions. In v2 that is collapsed to one - gpio_v2_line_flag. The handle and event requests are merged into a single request, the line request, as the two requests were mostly the same other than the edge detection provided by event requests. As a byproduct, the v2 uAPI allows for multiple lines producing edge events on the same line handle. This is a new capability as v1 only supports a single line in an event request. As a consequence, there are now only two types of file handle to be concerned with, the chip and the line, and it is clearer which ioctls apply to which type of handle. There is also some minor renaming of fields for consistency compared to their v1 counterparts, e.g. offset rather than lineoffset or line_offset, and consumer rather than consumer_label. Additionally, v1 GPIOHANDLES_MAX becomes GPIO_V2_LINES_MAX in v2 for clarity, and the gpiohandle_data __u8 array becomes a bitmap in gpio_v2_line_values. The v2 uAPI is mostly a reorganisation and extension of v1, so userspace code, particularly libgpiod, should readily port to it. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- include/uapi/linux/gpio.h | 291 +++++++++++++++++++++++++++++++++++++- 1 file changed, 284 insertions(+), 7 deletions(-) diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 285cc10355b2..5904f49399de 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -11,11 +11,14 @@ #ifndef _UAPI_GPIO_H_ #define _UAPI_GPIO_H_ +#include #include #include /* * The maximum size of name and label arrays. + * + * Must be a multiple of 8 to ensure 32/64-bit alignment of structs. */ #define GPIO_MAX_NAME_SIZE 32 @@ -32,6 +35,265 @@ struct gpiochip_info { __u32 lines; }; +/* + * Maximum number of requested lines. + * + * Must be no greater than 64, as bitmaps are restricted here to 64-bits + * for simplicity, and a multiple of 2 to ensure 32/64-bit alignment of + * structs. + */ +#define GPIO_V2_LINES_MAX 64 + +/* + * The maximum number of configuration attributes associated with a line + * request. + */ +#define GPIO_V2_LINE_NUM_ATTRS_MAX 10 + +/** + * enum gpio_v2_line_flag - &struct gpio_v2_line_attribute.flags values + * @GPIO_V2_LINE_FLAG_USED: line is not available for request + * @GPIO_V2_LINE_FLAG_ACTIVE_LOW: line active state is physical low + * @GPIO_V2_LINE_FLAG_INPUT: line is an input + * @GPIO_V2_LINE_FLAG_OUTPUT: line is an output + * @GPIO_V2_LINE_FLAG_EDGE_RISING: line detects rising (inactive to active) + * edges + * @GPIO_V2_LINE_FLAG_EDGE_FALLING: line detects falling (active to + * inactive) edges + * @GPIO_V2_LINE_FLAG_OPEN_DRAIN: line is an open drain output + * @GPIO_V2_LINE_FLAG_OPEN_SOURCE: line is an open source output + * @GPIO_V2_LINE_FLAG_BIAS_PULL_UP: line has pull-up bias enabled + * @GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN: line has pull-down bias enabled + * @GPIO_V2_LINE_FLAG_BIAS_DISABLED: line has bias disabled + */ +enum gpio_v2_line_flag { + GPIO_V2_LINE_FLAG_USED = _BITULL(0), + GPIO_V2_LINE_FLAG_ACTIVE_LOW = _BITULL(1), + GPIO_V2_LINE_FLAG_INPUT = _BITULL(2), + GPIO_V2_LINE_FLAG_OUTPUT = _BITULL(3), + GPIO_V2_LINE_FLAG_EDGE_RISING = _BITULL(4), + GPIO_V2_LINE_FLAG_EDGE_FALLING = _BITULL(5), + GPIO_V2_LINE_FLAG_OPEN_DRAIN = _BITULL(6), + GPIO_V2_LINE_FLAG_OPEN_SOURCE = _BITULL(7), + GPIO_V2_LINE_FLAG_BIAS_PULL_UP = _BITULL(8), + GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN = _BITULL(9), + GPIO_V2_LINE_FLAG_BIAS_DISABLED = _BITULL(10), +}; + +/** + * struct gpio_v2_line_values - Values of GPIO lines + * @bits: a bitmap containing the value of the lines, set to 1 for active + * and 0 for inactive. + * @mask: a bitmap identifying the lines to get or set, with each bit + * number corresponding to the index into &struct + * gpio_v2_line_request.offsets. + */ +struct gpio_v2_line_values { + __aligned_u64 bits; + __aligned_u64 mask; +}; + +/** + * enum gpio_v2_line_attr_id - &struct gpio_v2_line_attribute.id values + * identifying which field of the attribute union is in use. + * @GPIO_V2_LINE_ATTR_ID_FLAGS: flags field is in use + * @GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES: values field is in use + * @GPIO_V2_LINE_ATTR_ID_DEBOUNCE: debounce_period_us is in use + */ +enum gpio_v2_line_attr_id { + GPIO_V2_LINE_ATTR_ID_FLAGS = 1, + GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES = 2, + GPIO_V2_LINE_ATTR_ID_DEBOUNCE = 3, +}; + +/** + * struct gpio_v2_line_attribute - a configurable attribute of a line + * @id: attribute identifier with value from &enum gpio_v2_line_attr_id + * @padding: reserved for future use and must be zero filled + * @flags: if id is GPIO_V2_LINE_ATTR_ID_FLAGS, the flags for the GPIO + * line, with values from enum gpio_v2_line_flag, such as + * GPIO_V2_LINE_FLAG_ACTIVE_LOW, GPIO_V2_LINE_FLAG_OUTPUT etc, OR:ed + * together. This overrides the default flags contained in the &struct + * gpio_v2_line_config for the associated line. + * @values: if id is GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES, a bitmap + * containing the values to which the lines will be set, with each bit + * number corresponding to the index into &struct + * gpio_v2_line_request.offsets. + * @debounce_period_us: if id is GPIO_V2_LINE_ATTR_ID_DEBOUNCE, the desired + * debounce period, in microseconds + */ +struct gpio_v2_line_attribute { + __u32 id; + __u32 padding; + union { + __aligned_u64 flags; + __aligned_u64 values; + __u32 debounce_period_us; + }; +}; + +/** + * struct gpio_v2_line_config_attribute - a configuration attribute + * associated with one or more of the requested lines. + * @attr: the configurable attribute + * @mask: a bitmap identifying the lines to which the attribute applies, + * with each bit number corresponding to the index into &struct + * gpio_v2_line_request.offsets. + */ +struct gpio_v2_line_config_attribute { + struct gpio_v2_line_attribute attr; + __aligned_u64 mask; +}; + +/** + * struct gpio_v2_line_config - Configuration for GPIO lines + * @flags: flags for the GPIO lines, with values from enum + * gpio_v2_line_flag, such as GPIO_V2_LINE_FLAG_ACTIVE_LOW, + * GPIO_V2_LINE_FLAG_OUTPUT etc, OR:ed together. This is the default for + * all requested lines but may be overridden for particular lines using + * attrs. + * @num_attrs: the number of attributes in attrs + * @padding: reserved for future use and must be zero filled + * @attrs: the configuration attributes associated with the requested + * lines. Any attribute should only be associated with a particular line + * once. If an attribute is associated with a line multiple times then the + * first occurrence (i.e. lowest index) has precedence. + */ +struct gpio_v2_line_config { + __aligned_u64 flags; + __u32 num_attrs; + /* Pad to fill implicit padding and reserve space for future use. */ + __u32 padding[5]; + struct gpio_v2_line_config_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX]; +}; + +/** + * struct gpio_v2_line_request - Information about a request for GPIO lines + * @offsets: an array of desired lines, specified by offset index for the + * associated GPIO chip + * @consumer: a desired consumer label for the selected GPIO lines such as + * "my-bitbanged-relay" + * @config: requested configuration for the lines. + * @num_lines: number of lines requested in this request, i.e. the number + * of valid fields in the GPIO_V2_LINES_MAX sized arrays, set to 1 to + * request a single line + * @event_buffer_size: a suggested minimum number of line events that the + * kernel should buffer. This is only relevant if edge detection is + * enabled in the configuration. Note that this is only a suggested value + * and the kernel may allocate a larger buffer or cap the size of the + * buffer. If this field is zero then the buffer size defaults to a minimum + * of num_lines*16. + * @padding: reserved for future use and must be zero filled + * @fd: if successful this field will contain a valid anonymous file handle + * after a GPIO_GET_LINE_IOCTL operation, zero or negative value means + * error + */ +struct gpio_v2_line_request { + __u32 offsets[GPIO_V2_LINES_MAX]; + char consumer[GPIO_MAX_NAME_SIZE]; + struct gpio_v2_line_config config; + __u32 num_lines; + __u32 event_buffer_size; + /* Pad to fill implicit padding and reserve space for future use. */ + __u32 padding[5]; + __s32 fd; +}; + +/** + * struct gpio_v2_line_info - Information about a certain GPIO line + * @name: the name of this GPIO line, such as the output pin of the line on + * the chip, a rail or a pin header name on a board, as specified by the + * GPIO chip, may be empty + * @consumer: a functional name for the consumer of this GPIO line as set + * by whatever is using it, will be empty if there is no current user but + * may also be empty if the consumer doesn't set this up + * @flags: flags for the GPIO line, such as GPIO_V2_LINE_FLAG_ACTIVE_LOW, + * GPIO_V2_LINE_FLAG_OUTPUT etc, OR:ed together + * @offset: the local offset on this GPIO chip, fill this in when + * requesting the line information from the kernel + * @num_attrs: the number of attributes in attrs + * @attrs: the configuration attributes associated with the line + * @padding: reserved for future use + */ +struct gpio_v2_line_info { + char name[GPIO_MAX_NAME_SIZE]; + char consumer[GPIO_MAX_NAME_SIZE]; + __u32 offset; + __u32 num_attrs; + __aligned_u64 flags; + struct gpio_v2_line_attribute attrs[GPIO_V2_LINE_NUM_ATTRS_MAX]; + /* Space reserved for future use. */ + __u32 padding[4]; +}; + +/** + * enum gpio_v2_line_changed_type - &struct gpio_v2_line_changed.event_type + * values + * @GPIO_V2_LINE_CHANGED_REQUESTED: line has been requested + * @GPIO_V2_LINE_CHANGED_RELEASED: line has been released + * @GPIO_V2_LINE_CHANGED_CONFIG: line has been reconfigured + */ +enum gpio_v2_line_changed_type { + GPIO_V2_LINE_CHANGED_REQUESTED = 1, + GPIO_V2_LINE_CHANGED_RELEASED = 2, + GPIO_V2_LINE_CHANGED_CONFIG = 3, +}; + +/** + * struct gpio_v2_line_info_changed - Information about a change in status + * of a GPIO line + * @info: updated line information + * @timestamp_ns: estimate of time of status change occurrence, in nanoseconds + * @event_type: the type of change with a value from enum + * gpio_v2_line_changed_type + * @padding: reserved for future use + */ +struct gpio_v2_line_info_changed { + struct gpio_v2_line_info info; + __aligned_u64 timestamp_ns; + __u32 event_type; + /* Pad struct to 64-bit boundary and reserve space for future use. */ + __u32 padding[5]; +}; + +/** + * enum gpio_v2_line_event_id - &struct gpio_v2_line_event.id values + * @GPIO_V2_LINE_EVENT_RISING_EDGE: event triggered by a rising edge + * @GPIO_V2_LINE_EVENT_FALLING_EDGE: event triggered by a falling edge + */ +enum gpio_v2_line_event_id { + GPIO_V2_LINE_EVENT_RISING_EDGE = 1, + GPIO_V2_LINE_EVENT_FALLING_EDGE = 2, +}; + +/** + * struct gpio_v2_line_event - The actual event being pushed to userspace + * @timestamp_ns: best estimate of time of event occurrence, in nanoseconds. + * The timestamp_ns is read from CLOCK_MONOTONIC and is intended to allow the + * accurate measurement of the time between events. It does not provide + * the wall-clock time. + * @id: event identifier with value from enum gpio_v2_line_event_id + * @offset: the offset of the line that triggered the event + * @seqno: the sequence number for this event in the sequence of events for + * all the lines in this line request + * @line_seqno: the sequence number for this event in the sequence of + * events on this particular line + * @padding: reserved for future use + */ +struct gpio_v2_line_event { + __aligned_u64 timestamp_ns; + __u32 id; + __u32 offset; + __u32 seqno; + __u32 line_seqno; + /* Space reserved for future use. */ + __u32 padding[6]; +}; + +/* + * ABI v1 + */ + /* Informational flags */ #define GPIOLINE_FLAG_KERNEL (1UL << 0) /* Line used by the kernel */ #define GPIOLINE_FLAG_IS_OUT (1UL << 1) @@ -149,8 +411,6 @@ struct gpiohandle_config { __u32 padding[4]; /* padding for future use */ }; -#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0a, struct gpiohandle_config) - /** * struct gpiohandle_data - Information of values on a GPIO handle * @values: when getting the state of lines this contains the current @@ -161,9 +421,6 @@ struct gpiohandle_data { __u8 values[GPIOHANDLES_MAX]; }; -#define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data) -#define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data) - /* Eventrequest flags */ #define GPIOEVENT_REQUEST_RISING_EDGE (1UL << 0) #define GPIOEVENT_REQUEST_FALLING_EDGE (1UL << 1) @@ -207,11 +464,31 @@ struct gpioevent_data { __u32 id; }; +/* + * v1 and v2 ioctl()s + */ #define GPIO_GET_CHIPINFO_IOCTL _IOR(0xB4, 0x01, struct gpiochip_info) +#define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0C, __u32) + +/* + * v2 ioctl()s + */ +#define GPIO_V2_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x05, struct gpio_v2_line_info) +#define GPIO_V2_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x06, struct gpio_v2_line_info) +#define GPIO_V2_GET_LINE_IOCTL _IOWR(0xB4, 0x07, struct gpio_v2_line_request) +#define GPIO_V2_LINE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0D, struct gpio_v2_line_config) +#define GPIO_V2_LINE_GET_VALUES_IOCTL _IOWR(0xB4, 0x0E, struct gpio_v2_line_values) +#define GPIO_V2_LINE_SET_VALUES_IOCTL _IOWR(0xB4, 0x0F, struct gpio_v2_line_values) + +/* + * v1 ioctl()s + */ #define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info) -#define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0b, struct gpioline_info) -#define GPIO_GET_LINEINFO_UNWATCH_IOCTL _IOWR(0xB4, 0x0c, __u32) #define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request) #define GPIO_GET_LINEEVENT_IOCTL _IOWR(0xB4, 0x04, struct gpioevent_request) +#define GPIOHANDLE_GET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x08, struct gpiohandle_data) +#define GPIOHANDLE_SET_LINE_VALUES_IOCTL _IOWR(0xB4, 0x09, struct gpiohandle_data) +#define GPIOHANDLE_SET_CONFIG_IOCTL _IOWR(0xB4, 0x0A, struct gpiohandle_config) +#define GPIO_GET_LINEINFO_WATCH_IOCTL _IOWR(0xB4, 0x0B, struct gpioline_info) #endif /* _UAPI_GPIO_H_ */ From d143493c01b7fc3a9b9369a795e20329561222c5 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:52 +0800 Subject: [PATCH 17/32] gpiolib: make cdev a build option Make the gpiolib-cdev module a build option. This allows the CDEV interface to be removed from the kernel to reduce kernel size in applications where is it not required, and provides the parent for other CDEV interface specific build options to follow. Suggested-by: Bartosz Golaszewski Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/Kconfig | 17 +++++++++++++++-- drivers/gpio/Makefile | 2 +- drivers/gpio/gpiolib-cdev.h | 15 +++++++++++++++ 3 files changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index c7292a50aec4..cbf8a60dec03 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -66,8 +66,21 @@ config GPIO_SYSFS This ABI is deprecated. If you want to use GPIO from userspace, use the character device /dev/gpiochipN with the appropriate - ioctl() operations instead. The character device is always - available. + ioctl() operations instead. + +config GPIO_CDEV + bool + prompt "Character device (/dev/gpiochipN) support" if EXPERT + default y + help + Say Y here to add the character device /dev/gpiochipN interface + for GPIOs. The character device allows userspace to control GPIOs + using ioctl() operations. + + Only say N if you are sure that the GPIO character device is not + required. + + If unsure, say Y. config GPIO_GENERIC depends on HAS_IOMEM # Only for IOMEM drivers diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 639275eb4e4d..6c3791a55a7b 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -6,8 +6,8 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG obj-$(CONFIG_GPIOLIB) += gpiolib.o obj-$(CONFIG_GPIOLIB) += gpiolib-devres.o obj-$(CONFIG_GPIOLIB) += gpiolib-legacy.o -obj-$(CONFIG_GPIOLIB) += gpiolib-cdev.o obj-$(CONFIG_OF_GPIO) += gpiolib-of.o +obj-$(CONFIG_GPIO_CDEV) += gpiolib-cdev.o obj-$(CONFIG_GPIO_SYSFS) += gpiolib-sysfs.o obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o diff --git a/drivers/gpio/gpiolib-cdev.h b/drivers/gpio/gpiolib-cdev.h index 973578e7ad10..19a4e3d57120 100644 --- a/drivers/gpio/gpiolib-cdev.h +++ b/drivers/gpio/gpiolib-cdev.h @@ -5,7 +5,22 @@ #include +#ifdef CONFIG_GPIO_CDEV + int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt); void gpiolib_cdev_unregister(struct gpio_device *gdev); +#else + +static inline int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) +{ + return 0; +} + +static inline void gpiolib_cdev_unregister(struct gpio_device *gdev) +{ +} + +#endif /* CONFIG_GPIO_CDEV */ + #endif /* GPIOLIB_CDEV_H */ From 957ebb61a4761c1eb32c3f34db7ccfef2e1e95ae Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:53 +0800 Subject: [PATCH 18/32] gpiolib: add build option for CDEV v1 ABI Add a build option to allow the removal of the CDEV v1 ABI. Suggested-by: Bartosz Golaszewski Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- drivers/gpio/Kconfig | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index cbf8a60dec03..e1376466d8b0 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -82,6 +82,18 @@ config GPIO_CDEV If unsure, say Y. +config GPIO_CDEV_V1 + bool "Support GPIO ABI Version 1" + default y + depends on GPIO_CDEV + help + Say Y here to support version 1 of the GPIO CDEV ABI. + + This ABI version is deprecated. + Please use the latest ABI for new developments. + + If unsure, say Y. + config GPIO_GENERIC depends on HAS_IOMEM # Only for IOMEM drivers tristate From 3c0d9c635ae2b2c6416928271a452017b60e3f98 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:54 +0800 Subject: [PATCH 19/32] gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL Add support for requesting lines using the GPIO_V2_GET_LINE_IOCTL, and returning their current values using GPIO_V2_LINE_GET_VALUES_IOCTL. The struct linereq implementation is based on the v1 struct linehandle implementation. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 424 ++++++++++++++++++++++++++++++++++++ 1 file changed, 424 insertions(+) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 86679397d09c..a5f2256cdf8c 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -1,7 +1,9 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include #include +#include #include #include #include @@ -24,6 +26,25 @@ #include "gpiolib.h" #include "gpiolib-cdev.h" +/* + * Array sizes must ensure 64-bit alignment and not create holes in the + * struct packing. + */ +static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2)); +static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8)); + +/* + * Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility + */ +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8)); +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8)); +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8)); +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8)); +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8)); +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8)); +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8)); +static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); + /* Character device interface to GPIO. * * The GPIO character device, /dev/gpiochipN, provides userspace an @@ -34,6 +55,7 @@ * GPIO line handle management */ +#ifdef CONFIG_GPIO_CDEV_V1 /** * struct linehandle_state - contains the state of a userspace handle * @gdev: the GPIO device the handle pertains to @@ -376,6 +398,402 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) linehandle_free(lh); return ret; } +#endif /* CONFIG_GPIO_CDEV_V1 */ + +/** + * struct line - contains the state of a requested line + * @desc: the GPIO descriptor for this line. + */ +struct line { + struct gpio_desc *desc; +}; + +/** + * struct linereq - contains the state of a userspace line request + * @gdev: the GPIO device the line request pertains to + * @label: consumer label used to tag GPIO descriptors + * @num_lines: the number of lines in the lines array + * @lines: the lines held by this line request, with @num_lines elements. + */ +struct linereq { + struct gpio_device *gdev; + const char *label; + u32 num_lines; + struct line lines[]; +}; + +#define GPIO_V2_LINE_BIAS_FLAGS \ + (GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \ + GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \ + GPIO_V2_LINE_FLAG_BIAS_DISABLED) + +#define GPIO_V2_LINE_DIRECTION_FLAGS \ + (GPIO_V2_LINE_FLAG_INPUT | \ + GPIO_V2_LINE_FLAG_OUTPUT) + +#define GPIO_V2_LINE_DRIVE_FLAGS \ + (GPIO_V2_LINE_FLAG_OPEN_DRAIN | \ + GPIO_V2_LINE_FLAG_OPEN_SOURCE) + +#define GPIO_V2_LINE_VALID_FLAGS \ + (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ + GPIO_V2_LINE_DIRECTION_FLAGS | \ + GPIO_V2_LINE_DRIVE_FLAGS | \ + GPIO_V2_LINE_BIAS_FLAGS) + +static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, + unsigned int line_idx) +{ + unsigned int i; + u64 mask = BIT_ULL(line_idx); + + for (i = 0; i < lc->num_attrs; i++) { + if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) && + (lc->attrs[i].mask & mask)) + return lc->attrs[i].attr.flags; + } + return lc->flags; +} + +static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc, + unsigned int line_idx) +{ + unsigned int i; + u64 mask = BIT_ULL(line_idx); + + for (i = 0; i < lc->num_attrs; i++) { + if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) && + (lc->attrs[i].mask & mask)) + return !!(lc->attrs[i].attr.values & mask); + } + return 0; +} + +static int gpio_v2_line_flags_validate(u64 flags) +{ + /* Return an error if an unknown flag is set */ + if (flags & ~GPIO_V2_LINE_VALID_FLAGS) + return -EINVAL; + + /* + * Do not allow both INPUT and OUTPUT flags to be set as they are + * contradictory. + */ + if ((flags & GPIO_V2_LINE_FLAG_INPUT) && + (flags & GPIO_V2_LINE_FLAG_OUTPUT)) + return -EINVAL; + + /* + * Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single + * request. If the hardware actually supports enabling both at the + * same time the electrical result would be disastrous. + */ + if ((flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN) && + (flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE)) + return -EINVAL; + + /* Drive requires explicit output direction. */ + if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) && + !(flags & GPIO_V2_LINE_FLAG_OUTPUT)) + return -EINVAL; + + /* Bias requires explicit direction. */ + if ((flags & GPIO_V2_LINE_BIAS_FLAGS) && + !(flags & GPIO_V2_LINE_DIRECTION_FLAGS)) + return -EINVAL; + + /* Only one bias flag can be set. */ + if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) && + (flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | + GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) || + ((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) && + (flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) + return -EINVAL; + + return 0; +} + +static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, + unsigned int num_lines) +{ + unsigned int i; + u64 flags; + int ret; + + if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX) + return -EINVAL; + + if (memchr_inv(lc->padding, 0, sizeof(lc->padding))) + return -EINVAL; + + for (i = 0; i < num_lines; i++) { + flags = gpio_v2_line_config_flags(lc, i); + ret = gpio_v2_line_flags_validate(flags); + if (ret) + return ret; + } + return 0; +} + +static void gpio_v2_line_config_flags_to_desc_flags(u64 flags, + unsigned long *flagsp) +{ + assign_bit(FLAG_ACTIVE_LOW, flagsp, + flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); + + if (flags & GPIO_V2_LINE_FLAG_OUTPUT) + set_bit(FLAG_IS_OUT, flagsp); + else if (flags & GPIO_V2_LINE_FLAG_INPUT) + clear_bit(FLAG_IS_OUT, flagsp); + + assign_bit(FLAG_OPEN_DRAIN, flagsp, + flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN); + assign_bit(FLAG_OPEN_SOURCE, flagsp, + flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE); + + assign_bit(FLAG_PULL_UP, flagsp, + flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP); + assign_bit(FLAG_PULL_DOWN, flagsp, + flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN); + assign_bit(FLAG_BIAS_DISABLE, flagsp, + flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED); +} + +static long linereq_get_values(struct linereq *lr, void __user *ip) +{ + struct gpio_v2_line_values lv; + DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); + struct gpio_desc **descs; + unsigned int i, didx, num_get; + int ret; + + /* NOTE: It's ok to read values of output lines. */ + if (copy_from_user(&lv, ip, sizeof(lv))) + return -EFAULT; + + for (num_get = 0, i = 0; i < lr->num_lines; i++) { + if (lv.mask & BIT_ULL(i)) { + num_get++; + descs = &lr->lines[i].desc; + } + } + + if (num_get == 0) + return -EINVAL; + + if (num_get != 1) { + descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL); + if (!descs) + return -ENOMEM; + for (didx = 0, i = 0; i < lr->num_lines; i++) { + if (lv.mask & BIT_ULL(i)) { + descs[didx] = lr->lines[i].desc; + didx++; + } + } + } + ret = gpiod_get_array_value_complex(false, true, num_get, + descs, NULL, vals); + + if (num_get != 1) + kfree(descs); + if (ret) + return ret; + + lv.bits = 0; + for (didx = 0, i = 0; i < lr->num_lines; i++) { + if (lv.mask & BIT_ULL(i)) { + if (test_bit(didx, vals)) + lv.bits |= BIT_ULL(i); + didx++; + } + } + + if (copy_to_user(ip, &lv, sizeof(lv))) + return -EFAULT; + + return 0; +} + +static long linereq_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct linereq *lr = file->private_data; + void __user *ip = (void __user *)arg; + + if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL) + return linereq_get_values(lr, ip); + + return -EINVAL; +} + +#ifdef CONFIG_COMPAT +static long linereq_ioctl_compat(struct file *file, unsigned int cmd, + unsigned long arg) +{ + return linereq_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); +} +#endif + +static void linereq_free(struct linereq *lr) +{ + unsigned int i; + + for (i = 0; i < lr->num_lines; i++) { + if (lr->lines[i].desc) + gpiod_free(lr->lines[i].desc); + } + kfree(lr->label); + put_device(&lr->gdev->dev); + kfree(lr); +} + +static int linereq_release(struct inode *inode, struct file *file) +{ + struct linereq *lr = file->private_data; + + linereq_free(lr); + return 0; +} + +static const struct file_operations line_fileops = { + .release = linereq_release, + .owner = THIS_MODULE, + .llseek = noop_llseek, + .unlocked_ioctl = linereq_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = linereq_ioctl_compat, +#endif +}; + +static int linereq_create(struct gpio_device *gdev, void __user *ip) +{ + struct gpio_v2_line_request ulr; + struct gpio_v2_line_config *lc; + struct linereq *lr; + struct file *file; + u64 flags; + unsigned int i; + int fd, ret; + + if (copy_from_user(&ulr, ip, sizeof(ulr))) + return -EFAULT; + + if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX)) + return -EINVAL; + + if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding))) + return -EINVAL; + + lc = &ulr.config; + ret = gpio_v2_line_config_validate(lc, ulr.num_lines); + if (ret) + return ret; + + lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL); + if (!lr) + return -ENOMEM; + + lr->gdev = gdev; + get_device(&gdev->dev); + + /* Make sure this is terminated */ + ulr.consumer[sizeof(ulr.consumer)-1] = '\0'; + if (strlen(ulr.consumer)) { + /* label is only initialized if consumer is set */ + lr->label = kstrdup(ulr.consumer, GFP_KERNEL); + if (!lr->label) { + ret = -ENOMEM; + goto out_free_linereq; + } + } + + lr->num_lines = ulr.num_lines; + + /* Request each GPIO */ + for (i = 0; i < ulr.num_lines; i++) { + u32 offset = ulr.offsets[i]; + struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); + + if (IS_ERR(desc)) { + ret = PTR_ERR(desc); + goto out_free_linereq; + } + + ret = gpiod_request(desc, lr->label); + if (ret) + goto out_free_linereq; + + lr->lines[i].desc = desc; + flags = gpio_v2_line_config_flags(lc, i); + gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); + + ret = gpiod_set_transitory(desc, false); + if (ret < 0) + goto out_free_linereq; + + /* + * Lines have to be requested explicitly for input + * or output, else the line will be treated "as is". + */ + if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { + int val = gpio_v2_line_config_output_value(lc, i); + + ret = gpiod_direction_output(desc, val); + if (ret) + goto out_free_linereq; + } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { + ret = gpiod_direction_input(desc); + if (ret) + goto out_free_linereq; + } + + blocking_notifier_call_chain(&desc->gdev->notifier, + GPIOLINE_CHANGED_REQUESTED, desc); + + dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", + offset); + } + + fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); + if (fd < 0) { + ret = fd; + goto out_free_linereq; + } + + file = anon_inode_getfile("gpio-line", &line_fileops, lr, + O_RDONLY | O_CLOEXEC); + if (IS_ERR(file)) { + ret = PTR_ERR(file); + goto out_put_unused_fd; + } + + ulr.fd = fd; + if (copy_to_user(ip, &ulr, sizeof(ulr))) { + /* + * fput() will trigger the release() callback, so do not go onto + * the regular error cleanup path here. + */ + fput(file); + put_unused_fd(fd); + return -EFAULT; + } + + fd_install(fd, file); + + dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", + lr->num_lines); + + return 0; + +out_put_unused_fd: + put_unused_fd(fd); +out_free_linereq: + linereq_free(lr); + return ret; +} + +#ifdef CONFIG_GPIO_CDEV_V1 /* * GPIO line event management @@ -745,6 +1163,8 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip) return ret; } +#endif /* CONFIG_GPIO_CDEV_V1 */ + static void gpio_desc_to_lineinfo(struct gpio_desc *desc, struct gpioline_info *info) { @@ -843,6 +1263,7 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) return -EFAULT; return 0; +#ifdef CONFIG_GPIO_CDEV_V1 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) { struct gpioline_info lineinfo; @@ -885,6 +1306,9 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } return 0; +#endif /* CONFIG_GPIO_CDEV_V1 */ + } else if (cmd == GPIO_V2_GET_LINE_IOCTL) { + return linereq_create(gdev, ip); } else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) { if (copy_from_user(&offset, ip, sizeof(offset))) return -EFAULT; From aad955842d1cdf56d31e600112137d82fd431140 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:55 +0800 Subject: [PATCH 20/32] gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL Add support for GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL. The core of this change is the event kfifo switching to contain struct gpioline_info_changed_v2, instead of v1 as v2 is richer. The two uAPI versions are mostly independent - other than where they both provide line info changes via reads on the chip fd. As the info change structs differ between v1 and v2, the infowatch implementation tracks which version of the infowatch ioctl, either GPIO_GET_LINEINFO_WATCH_IOCTL or GPIO_V2_GET_LINEINFO_WATCH_IOCTL, initiates the initial watch and returns the corresponding info change struct to the read. The version supported on that fd locks to that version on the first watch request, so subsequent watches from that process must use the same uAPI version. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 196 ++++++++++++++++++++++++++++++------ 1 file changed, 168 insertions(+), 28 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index a5f2256cdf8c..786e667cdc85 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -181,7 +181,8 @@ static long linehandle_set_config(struct linehandle_state *lh, } blocking_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_CONFIG, desc); + GPIO_V2_LINE_CHANGED_CONFIG, + desc); } return 0; } @@ -353,7 +354,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) } blocking_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_REQUESTED, desc); + GPIO_V2_LINE_CHANGED_REQUESTED, desc); dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", offset); @@ -749,7 +750,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) } blocking_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_REQUESTED, desc); + GPIO_V2_LINE_CHANGED_REQUESTED, desc); dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", offset); @@ -1096,7 +1097,7 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip) goto out_free_le; blocking_notifier_call_chain(&desc->gdev->notifier, - GPIOLINE_CHANGED_REQUESTED, desc); + GPIO_V2_LINE_CHANGED_REQUESTED, desc); irq = gpiod_to_irq(desc); if (irq <= 0) { @@ -1163,17 +1164,58 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip) return ret; } +static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2, + struct gpioline_info *info_v1) +{ + u64 flagsv2 = info_v2->flags; + + memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name)); + memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer)); + info_v1->line_offset = info_v2->offset; + info_v1->flags = 0; + + if (flagsv2 & GPIO_V2_LINE_FLAG_USED) + info_v1->flags |= GPIOLINE_FLAG_KERNEL; + + if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT) + info_v1->flags |= GPIOLINE_FLAG_IS_OUT; + + if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW) + info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW; + + if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN) + info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN; + if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE) + info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE; + + if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP) + info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; + if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) + info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; + if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED) + info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE; +} + +static void gpio_v2_line_info_changed_to_v1( + struct gpio_v2_line_info_changed *lic_v2, + struct gpioline_info_changed *lic_v1) +{ + gpio_v2_line_info_to_v1(&lic_v2->info, &lic_v1->info); + lic_v1->timestamp = lic_v2->timestamp_ns; + lic_v1->event_type = lic_v2->event_type; +} + #endif /* CONFIG_GPIO_CDEV_V1 */ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, - struct gpioline_info *info) + struct gpio_v2_line_info *info) { struct gpio_chip *gc = desc->gdev->chip; bool ok_for_pinctrl; unsigned long flags; memset(info, 0, sizeof(*info)); - info->line_offset = gpio_chip_hwgpio(desc); + info->offset = gpio_chip_hwgpio(desc); /* * This function takes a mutex so we must check this before taking @@ -1183,7 +1225,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, * lock common to both frameworks? */ ok_for_pinctrl = - pinctrl_gpio_can_use_line(gc->base + info->line_offset); + pinctrl_gpio_can_use_line(gc->base + info->offset); spin_lock_irqsave(&gpio_lock, flags); @@ -1204,23 +1246,27 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, test_bit(FLAG_EXPORT, &desc->flags) || test_bit(FLAG_SYSFS, &desc->flags) || !ok_for_pinctrl) - info->flags |= GPIOLINE_FLAG_KERNEL; + info->flags |= GPIO_V2_LINE_FLAG_USED; + if (test_bit(FLAG_IS_OUT, &desc->flags)) - info->flags |= GPIOLINE_FLAG_IS_OUT; + info->flags |= GPIO_V2_LINE_FLAG_OUTPUT; + else + info->flags |= GPIO_V2_LINE_FLAG_INPUT; + if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) - info->flags |= GPIOLINE_FLAG_ACTIVE_LOW; + info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW; + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) - info->flags |= (GPIOLINE_FLAG_OPEN_DRAIN | - GPIOLINE_FLAG_IS_OUT); + info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) - info->flags |= (GPIOLINE_FLAG_OPEN_SOURCE | - GPIOLINE_FLAG_IS_OUT); + info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE; + if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) - info->flags |= GPIOLINE_FLAG_BIAS_DISABLE; + info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED; if (test_bit(FLAG_PULL_DOWN, &desc->flags)) - info->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; + info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN; if (test_bit(FLAG_PULL_UP, &desc->flags)) - info->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; + info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP; spin_unlock_irqrestore(&gpio_lock, flags); } @@ -1228,11 +1274,65 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, struct gpio_chardev_data { struct gpio_device *gdev; wait_queue_head_t wait; - DECLARE_KFIFO(events, struct gpioline_info_changed, 32); + DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32); struct notifier_block lineinfo_changed_nb; unsigned long *watched_lines; +#ifdef CONFIG_GPIO_CDEV_V1 + atomic_t watch_abi_version; +#endif }; +#ifdef CONFIG_GPIO_CDEV_V1 +/* + * returns 0 if the versions match, else the previously selected ABI version + */ +static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, + unsigned int version) +{ + int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version); + + if (abiv == version) + return 0; + + return abiv; +} +#endif + +static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, + bool watch) +{ + struct gpio_desc *desc; + struct gpio_v2_line_info lineinfo; + + if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) + return -EFAULT; + + if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding))) + return -EINVAL; + + desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.offset); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + if (watch) { +#ifdef CONFIG_GPIO_CDEV_V1 + if (lineinfo_ensure_abi_version(cdev, 2)) + return -EPERM; +#endif + if (test_and_set_bit(lineinfo.offset, cdev->watched_lines)) + return -EBUSY; + } + gpio_desc_to_lineinfo(desc, &lineinfo); + + if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { + if (watch) + clear_bit(lineinfo.offset, cdev->watched_lines); + return -EFAULT; + } + + return 0; +} + /* * gpio_ioctl() - ioctl handler for the GPIO chardev */ @@ -1242,7 +1342,6 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) struct gpio_device *gdev = cdev->gdev; struct gpio_chip *gc = gdev->chip; void __user *ip = (void __user *)arg; - struct gpio_desc *desc; __u32 offset; /* We fail any subsequent ioctl():s when the chip is gone */ @@ -1265,7 +1364,9 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return 0; #ifdef CONFIG_GPIO_CDEV_V1 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) { + struct gpio_desc *desc; struct gpioline_info lineinfo; + struct gpio_v2_line_info lineinfo_v2; if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; @@ -1275,7 +1376,8 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (IS_ERR(desc)) return PTR_ERR(desc); - gpio_desc_to_lineinfo(desc, &lineinfo); + gpio_desc_to_lineinfo(desc, &lineinfo_v2); + gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) return -EFAULT; @@ -1285,7 +1387,9 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) { return lineevent_create(gdev, ip); } else if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) { + struct gpio_desc *desc; struct gpioline_info lineinfo; + struct gpio_v2_line_info lineinfo_v2; if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; @@ -1295,10 +1399,14 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (IS_ERR(desc)) return PTR_ERR(desc); + if (lineinfo_ensure_abi_version(cdev, 1)) + return -EPERM; + if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) return -EBUSY; - gpio_desc_to_lineinfo(desc, &lineinfo); + gpio_desc_to_lineinfo(desc, &lineinfo_v2); + gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { clear_bit(lineinfo.line_offset, cdev->watched_lines); @@ -1307,6 +1415,10 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return 0; #endif /* CONFIG_GPIO_CDEV_V1 */ + } else if (cmd == GPIO_V2_GET_LINEINFO_IOCTL || + cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL) { + return lineinfo_get(cdev, ip, + cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL); } else if (cmd == GPIO_V2_GET_LINE_IOCTL) { return linereq_create(gdev, ip); } else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) { @@ -1342,7 +1454,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb, unsigned long action, void *data) { struct gpio_chardev_data *cdev = to_gpio_chardev_data(nb); - struct gpioline_info_changed chg; + struct gpio_v2_line_info_changed chg; struct gpio_desc *desc = data; int ret; @@ -1351,7 +1463,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb, memset(&chg, 0, sizeof(chg)); chg.event_type = action; - chg.timestamp = ktime_get_ns(); + chg.timestamp_ns = ktime_get_ns(); gpio_desc_to_lineinfo(desc, &chg.info); ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock); @@ -1382,12 +1494,16 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, size_t count, loff_t *off) { struct gpio_chardev_data *cdev = file->private_data; - struct gpioline_info_changed event; + struct gpio_v2_line_info_changed event; ssize_t bytes_read = 0; int ret; + size_t event_size; - if (count < sizeof(event)) +#ifndef CONFIG_GPIO_CDEV_V1 + event_size = sizeof(struct gpio_v2_line_info_changed); + if (count < event_size) return -EINVAL; +#endif do { spin_lock(&cdev->wait.lock); @@ -1409,7 +1525,17 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, return ret; } } - +#ifdef CONFIG_GPIO_CDEV_V1 + /* must be after kfifo check so watch_abi_version is set */ + if (atomic_read(&cdev->watch_abi_version) == 2) + event_size = sizeof(struct gpio_v2_line_info_changed); + else + event_size = sizeof(struct gpioline_info_changed); + if (count < event_size) { + spin_unlock(&cdev->wait.lock); + return -EINVAL; + } +#endif ret = kfifo_out(&cdev->events, &event, 1); spin_unlock(&cdev->wait.lock); if (ret != 1) { @@ -1418,9 +1544,23 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, /* We should never get here. See lineevent_read(). */ } - if (copy_to_user(buf + bytes_read, &event, sizeof(event))) +#ifdef CONFIG_GPIO_CDEV_V1 + if (event_size == sizeof(struct gpio_v2_line_info_changed)) { + if (copy_to_user(buf + bytes_read, &event, event_size)) + return -EFAULT; + } else { + struct gpioline_info_changed event_v1; + + gpio_v2_line_info_changed_to_v1(&event, &event_v1); + if (copy_to_user(buf + bytes_read, &event_v1, + event_size)) + return -EFAULT; + } +#else + if (copy_to_user(buf + bytes_read, &event, event_size)) return -EFAULT; - bytes_read += sizeof(event); +#endif + bytes_read += event_size; } while (count >= bytes_read + sizeof(event)); return bytes_read; From 73e0341992b68bb3e748134ea8c7473f9d4e279f Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:56 +0800 Subject: [PATCH 21/32] gpiolib: cdev: support edge detection for uAPI v2 Add support for edge detection to lines requested using GPIO_V2_GET_LINE_IOCTL. The edge_detector implementation is based on the v1 lineevent implementation. Unlike the v1 implementation, an overflow of the event buffer results in discarding older events, rather than the most recent, so the final event in a burst will correspond to the current state of the line. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 277 ++++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib.c | 2 + drivers/gpio/gpiolib.h | 2 + 3 files changed, 281 insertions(+) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 786e667cdc85..868fcf89478c 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -404,9 +404,33 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) /** * struct line - contains the state of a requested line * @desc: the GPIO descriptor for this line. + * @req: the corresponding line request + * @irq: the interrupt triggered in response to events on this GPIO + * @eflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or + * GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied + * @timestamp_ns: cache for the timestamp storing it between hardirq and + * IRQ thread, used to bring the timestamp close to the actual event + * @req_seqno: the seqno for the current edge event in the sequence of + * events for the corresponding line request. This is drawn from the @req. + * @line_seqno: the seqno for the current edge event in the sequence of + * events for this line. */ struct line { struct gpio_desc *desc; + /* + * -- edge detector specific fields -- + */ + struct linereq *req; + unsigned int irq; + u64 eflags; + /* + * timestamp_ns and req_seqno are accessed only by + * edge_irq_handler() and edge_irq_thread(), which are themselves + * mutually exclusive, so no additional protection is necessary. + */ + u64 timestamp_ns; + u32 req_seqno; + u32 line_seqno; }; /** @@ -414,12 +438,22 @@ struct line { * @gdev: the GPIO device the line request pertains to * @label: consumer label used to tag GPIO descriptors * @num_lines: the number of lines in the lines array + * @wait: wait queue that handles blocking reads of events + * @event_buffer_size: the number of elements allocated in @events + * @events: KFIFO for the GPIO events + * @seqno: the sequence number for edge events generated on all lines in + * this line request. Note that this is not used when @num_lines is 1, as + * the line_seqno is then the same and is cheaper to calculate. * @lines: the lines held by this line request, with @num_lines elements. */ struct linereq { struct gpio_device *gdev; const char *label; u32 num_lines; + wait_queue_head_t wait; + u32 event_buffer_size; + DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); + atomic_t seqno; struct line lines[]; }; @@ -436,12 +470,151 @@ struct linereq { (GPIO_V2_LINE_FLAG_OPEN_DRAIN | \ GPIO_V2_LINE_FLAG_OPEN_SOURCE) +#define GPIO_V2_LINE_EDGE_FLAGS \ + (GPIO_V2_LINE_FLAG_EDGE_RISING | \ + GPIO_V2_LINE_FLAG_EDGE_FALLING) + #define GPIO_V2_LINE_VALID_FLAGS \ (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ GPIO_V2_LINE_DIRECTION_FLAGS | \ GPIO_V2_LINE_DRIVE_FLAGS | \ + GPIO_V2_LINE_EDGE_FLAGS | \ GPIO_V2_LINE_BIAS_FLAGS) +static void linereq_put_event(struct linereq *lr, + struct gpio_v2_line_event *le) +{ + bool overflow = false; + + spin_lock(&lr->wait.lock); + if (kfifo_is_full(&lr->events)) { + overflow = true; + kfifo_skip(&lr->events); + } + kfifo_in(&lr->events, le, 1); + spin_unlock(&lr->wait.lock); + if (!overflow) + wake_up_poll(&lr->wait, EPOLLIN); + else + pr_debug_ratelimited("event FIFO is full - event dropped\n"); +} + +static irqreturn_t edge_irq_thread(int irq, void *p) +{ + struct line *line = p; + struct linereq *lr = line->req; + struct gpio_v2_line_event le; + + /* Do not leak kernel stack to userspace */ + memset(&le, 0, sizeof(le)); + + if (line->timestamp_ns) { + le.timestamp_ns = line->timestamp_ns; + } else { + /* + * We may be running from a nested threaded interrupt in + * which case we didn't get the timestamp from + * edge_irq_handler(). + */ + le.timestamp_ns = ktime_get_ns(); + if (lr->num_lines != 1) + line->req_seqno = atomic_inc_return(&lr->seqno); + } + line->timestamp_ns = 0; + + if (line->eflags == (GPIO_V2_LINE_FLAG_EDGE_RISING | + GPIO_V2_LINE_FLAG_EDGE_FALLING)) { + int level = gpiod_get_value_cansleep(line->desc); + + if (level) + /* Emit low-to-high event */ + le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; + else + /* Emit high-to-low event */ + le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; + } else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) { + /* Emit low-to-high event */ + le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; + } else if (line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) { + /* Emit high-to-low event */ + le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; + } else { + return IRQ_NONE; + } + line->line_seqno++; + le.line_seqno = line->line_seqno; + le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; + le.offset = gpio_chip_hwgpio(line->desc); + + linereq_put_event(lr, &le); + + return IRQ_HANDLED; +} + +static irqreturn_t edge_irq_handler(int irq, void *p) +{ + struct line *line = p; + struct linereq *lr = line->req; + + /* + * Just store the timestamp in hardirq context so we get it as + * close in time as possible to the actual event. + */ + line->timestamp_ns = ktime_get_ns(); + + if (lr->num_lines != 1) + line->req_seqno = atomic_inc_return(&lr->seqno); + + return IRQ_WAKE_THREAD; +} + +static void edge_detector_stop(struct line *line) +{ + if (line->irq) { + free_irq(line->irq, line); + line->irq = 0; + } +} + +static int edge_detector_setup(struct line *line, + u64 eflags) +{ + unsigned long irqflags = 0; + int irq, ret; + + if (eflags && !kfifo_initialized(&line->req->events)) { + ret = kfifo_alloc(&line->req->events, + line->req->event_buffer_size, GFP_KERNEL); + if (ret) + return ret; + } + line->eflags = eflags; + + if (!eflags) + return 0; + + irq = gpiod_to_irq(line->desc); + if (irq < 0) + return -ENXIO; + + if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) + irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; + if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) + irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? + IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; + irqflags |= IRQF_ONESHOT; + + /* Request a thread to read the events */ + ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread, + irqflags, line->req->label, line); + if (ret) + return ret; + + line->irq = irq; + return 0; +} + static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, unsigned int line_idx) { @@ -484,6 +657,11 @@ static int gpio_v2_line_flags_validate(u64 flags) (flags & GPIO_V2_LINE_FLAG_OUTPUT)) return -EINVAL; + /* Edge detection requires explicit input. */ + if ((flags & GPIO_V2_LINE_EDGE_FLAGS) && + !(flags & GPIO_V2_LINE_FLAG_INPUT)) + return -EINVAL; + /* * Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single * request. If the hardware actually supports enabling both at the @@ -547,6 +725,11 @@ static void gpio_v2_line_config_flags_to_desc_flags(u64 flags, else if (flags & GPIO_V2_LINE_FLAG_INPUT) clear_bit(FLAG_IS_OUT, flagsp); + assign_bit(FLAG_EDGE_RISING, flagsp, + flags & GPIO_V2_LINE_FLAG_EDGE_RISING); + assign_bit(FLAG_EDGE_FALLING, flagsp, + flags & GPIO_V2_LINE_FLAG_EDGE_FALLING); + assign_bit(FLAG_OPEN_DRAIN, flagsp, flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN); assign_bit(FLAG_OPEN_SOURCE, flagsp, @@ -636,14 +819,85 @@ static long linereq_ioctl_compat(struct file *file, unsigned int cmd, } #endif +static __poll_t linereq_poll(struct file *file, + struct poll_table_struct *wait) +{ + struct linereq *lr = file->private_data; + __poll_t events = 0; + + poll_wait(file, &lr->wait, wait); + + if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events, + &lr->wait.lock)) + events = EPOLLIN | EPOLLRDNORM; + + return events; +} + +static ssize_t linereq_read(struct file *file, + char __user *buf, + size_t count, + loff_t *f_ps) +{ + struct linereq *lr = file->private_data; + struct gpio_v2_line_event le; + ssize_t bytes_read = 0; + int ret; + + if (count < sizeof(le)) + return -EINVAL; + + do { + spin_lock(&lr->wait.lock); + if (kfifo_is_empty(&lr->events)) { + if (bytes_read) { + spin_unlock(&lr->wait.lock); + return bytes_read; + } + + if (file->f_flags & O_NONBLOCK) { + spin_unlock(&lr->wait.lock); + return -EAGAIN; + } + + ret = wait_event_interruptible_locked(lr->wait, + !kfifo_is_empty(&lr->events)); + if (ret) { + spin_unlock(&lr->wait.lock); + return ret; + } + } + + ret = kfifo_out(&lr->events, &le, 1); + spin_unlock(&lr->wait.lock); + if (ret != 1) { + /* + * This should never happen - we were holding the + * lock from the moment we learned the fifo is no + * longer empty until now. + */ + ret = -EIO; + break; + } + + if (copy_to_user(buf + bytes_read, &le, sizeof(le))) + return -EFAULT; + bytes_read += sizeof(le); + } while (count >= bytes_read + sizeof(le)); + + return bytes_read; +} + static void linereq_free(struct linereq *lr) { unsigned int i; for (i = 0; i < lr->num_lines; i++) { + edge_detector_stop(&lr->lines[i]); if (lr->lines[i].desc) gpiod_free(lr->lines[i].desc); } + kfifo_free(&lr->events); kfree(lr->label); put_device(&lr->gdev->dev); kfree(lr); @@ -659,6 +913,8 @@ static int linereq_release(struct inode *inode, struct file *file) static const struct file_operations line_fileops = { .release = linereq_release, + .read = linereq_read, + .poll = linereq_poll, .owner = THIS_MODULE, .llseek = noop_llseek, .unlocked_ioctl = linereq_ioctl, @@ -698,6 +954,9 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) lr->gdev = gdev; get_device(&gdev->dev); + for (i = 0; i < ulr.num_lines; i++) + lr->lines[i].req = lr; + /* Make sure this is terminated */ ulr.consumer[sizeof(ulr.consumer)-1] = '\0'; if (strlen(ulr.consumer)) { @@ -709,6 +968,14 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) } } + init_waitqueue_head(&lr->wait); + lr->event_buffer_size = ulr.event_buffer_size; + if (lr->event_buffer_size == 0) + lr->event_buffer_size = ulr.num_lines * 16; + else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16) + lr->event_buffer_size = GPIO_V2_LINES_MAX * 16; + + atomic_set(&lr->seqno, 0); lr->num_lines = ulr.num_lines; /* Request each GPIO */ @@ -747,6 +1014,11 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) ret = gpiod_direction_input(desc); if (ret) goto out_free_linereq; + + ret = edge_detector_setup(&lr->lines[i], + flags & GPIO_V2_LINE_EDGE_FLAGS); + if (ret) + goto out_free_linereq; } blocking_notifier_call_chain(&desc->gdev->notifier, @@ -1268,6 +1540,11 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, if (test_bit(FLAG_PULL_UP, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP; + if (test_bit(FLAG_EDGE_RISING, &desc->flags)) + info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING; + if (test_bit(FLAG_EDGE_FALLING, &desc->flags)) + info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; + spin_unlock_irqrestore(&gpio_lock, flags); } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index dfcff5d24b18..aa20481e9452 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2092,6 +2092,8 @@ static bool gpiod_free_commit(struct gpio_desc *desc) clear_bit(FLAG_PULL_UP, &desc->flags); clear_bit(FLAG_PULL_DOWN, &desc->flags); clear_bit(FLAG_BIAS_DISABLE, &desc->flags); + clear_bit(FLAG_EDGE_RISING, &desc->flags); + clear_bit(FLAG_EDGE_FALLING, &desc->flags); clear_bit(FLAG_IS_HOGGED, &desc->flags); #ifdef CONFIG_OF_DYNAMIC desc->hog = NULL; diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 6709f79c02dd..39b356160937 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -114,6 +114,8 @@ struct gpio_desc { #define FLAG_PULL_UP 13 /* GPIO has pull up enabled */ #define FLAG_PULL_DOWN 14 /* GPIO has pull down enabled */ #define FLAG_BIAS_DISABLE 15 /* GPIO has pull disabled */ +#define FLAG_EDGE_RISING 16 /* GPIO CDEV detects rising edge events */ +#define FLAG_EDGE_FALLING 17 /* GPIO CDEV detects falling edge events */ /* Connection label */ const char *label; From a54756cb24eafac70ce92bfbd9bb4a4195689fb4 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:57 +0800 Subject: [PATCH 22/32] gpiolib: cdev: support GPIO_V2_LINE_SET_CONFIG_IOCTL Add support for GPIO_V2_LINE_SET_CONFIG_IOCTL, the uAPI v2 line set config ioctl. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 88 +++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 868fcf89478c..608cdbd1d579 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -444,6 +445,8 @@ struct line { * @seqno: the sequence number for edge events generated on all lines in * this line request. Note that this is not used when @num_lines is 1, as * the line_seqno is then the same and is cheaper to calculate. + * @config_mutex: mutex for serializing ioctl() calls to ensure consistency + * of configuration, particularly multi-step accesses to desc flags. * @lines: the lines held by this line request, with @num_lines elements. */ struct linereq { @@ -454,6 +457,7 @@ struct linereq { u32 event_buffer_size; DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); atomic_t seqno; + struct mutex config_mutex; struct line lines[]; }; @@ -574,6 +578,8 @@ static void edge_detector_stop(struct line *line) free_irq(line->irq, line); line->irq = 0; } + + line->eflags = 0; } static int edge_detector_setup(struct line *line, @@ -615,6 +621,17 @@ static int edge_detector_setup(struct line *line, return 0; } +static int edge_detector_update(struct line *line, u64 eflags, + bool polarity_change) +{ + if ((line->eflags == eflags) && !polarity_change) + return 0; + + edge_detector_stop(line); + + return edge_detector_setup(line, eflags); +} + static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, unsigned int line_idx) { @@ -799,6 +816,74 @@ static long linereq_get_values(struct linereq *lr, void __user *ip) return 0; } +static long linereq_set_config_unlocked(struct linereq *lr, + struct gpio_v2_line_config *lc) +{ + struct gpio_desc *desc; + unsigned int i; + u64 flags; + bool polarity_change; + int ret; + + for (i = 0; i < lr->num_lines; i++) { + desc = lr->lines[i].desc; + flags = gpio_v2_line_config_flags(lc, i); + polarity_change = + (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) != + ((flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) != 0)); + + gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); + /* + * Lines have to be requested explicitly for input + * or output, else the line will be treated "as is". + */ + if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { + int val = gpio_v2_line_config_output_value(lc, i); + + edge_detector_stop(&lr->lines[i]); + ret = gpiod_direction_output(desc, val); + if (ret) + return ret; + } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { + ret = gpiod_direction_input(desc); + if (ret) + return ret; + + ret = edge_detector_update(&lr->lines[i], + flags & GPIO_V2_LINE_EDGE_FLAGS, + polarity_change); + if (ret) + return ret; + } + + blocking_notifier_call_chain(&desc->gdev->notifier, + GPIO_V2_LINE_CHANGED_CONFIG, + desc); + } + return 0; +} + +static long linereq_set_config(struct linereq *lr, void __user *ip) +{ + struct gpio_v2_line_config lc; + int ret; + + if (copy_from_user(&lc, ip, sizeof(lc))) + return -EFAULT; + + ret = gpio_v2_line_config_validate(&lc, lr->num_lines); + if (ret) + return ret; + + mutex_lock(&lr->config_mutex); + + ret = linereq_set_config_unlocked(lr, &lc); + + mutex_unlock(&lr->config_mutex); + + return ret; +} + static long linereq_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -807,6 +892,8 @@ static long linereq_ioctl(struct file *file, unsigned int cmd, if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL) return linereq_get_values(lr, ip); + else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL) + return linereq_set_config(lr, ip); return -EINVAL; } @@ -968,6 +1055,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) } } + mutex_init(&lr->config_mutex); init_waitqueue_head(&lr->wait); lr->event_buffer_size = ulr.event_buffer_size; if (lr->event_buffer_size == 0) From 7b8e00d981680ddbbdd9874a7b46e0da58a2da4b Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:58 +0800 Subject: [PATCH 23/32] gpiolib: cdev: support GPIO_V2_LINE_SET_VALUES_IOCTL Add support for the GPIO_V2_LINE_SET_VALUES_IOCTL. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 61 +++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 608cdbd1d579..25536aae3e18 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -816,6 +816,65 @@ static long linereq_get_values(struct linereq *lr, void __user *ip) return 0; } +static long linereq_set_values_unlocked(struct linereq *lr, + struct gpio_v2_line_values *lv) +{ + DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); + struct gpio_desc **descs; + unsigned int i, didx, num_set; + int ret; + + bitmap_zero(vals, GPIO_V2_LINES_MAX); + for (num_set = 0, i = 0; i < lr->num_lines; i++) { + if (lv->mask & BIT_ULL(i)) { + if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags)) + return -EPERM; + if (lv->bits & BIT_ULL(i)) + __set_bit(num_set, vals); + num_set++; + descs = &lr->lines[i].desc; + } + } + if (num_set == 0) + return -EINVAL; + + if (num_set != 1) { + /* build compacted desc array and values */ + descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL); + if (!descs) + return -ENOMEM; + for (didx = 0, i = 0; i < lr->num_lines; i++) { + if (lv->mask & BIT_ULL(i)) { + descs[didx] = lr->lines[i].desc; + didx++; + } + } + } + ret = gpiod_set_array_value_complex(false, true, num_set, + descs, NULL, vals); + + if (num_set != 1) + kfree(descs); + return ret; +} + +static long linereq_set_values(struct linereq *lr, void __user *ip) +{ + struct gpio_v2_line_values lv; + int ret; + + if (copy_from_user(&lv, ip, sizeof(lv))) + return -EFAULT; + + mutex_lock(&lr->config_mutex); + + ret = linereq_set_values_unlocked(lr, &lv); + + mutex_unlock(&lr->config_mutex); + + return ret; +} + static long linereq_set_config_unlocked(struct linereq *lr, struct gpio_v2_line_config *lc) { @@ -892,6 +951,8 @@ static long linereq_ioctl(struct file *file, unsigned int cmd, if (cmd == GPIO_V2_LINE_GET_VALUES_IOCTL) return linereq_get_values(lr, ip); + else if (cmd == GPIO_V2_LINE_SET_VALUES_IOCTL) + return linereq_set_values(lr, ip); else if (cmd == GPIO_V2_LINE_SET_CONFIG_IOCTL) return linereq_set_config(lr, ip); From 65cff70464068a823b3f4a28074000febdce0630 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:27:59 +0800 Subject: [PATCH 24/32] gpiolib: cdev: support setting debounce Add support for setting debounce on a line via the GPIO uAPI. Where debounce is not supported by hardware, a software debounce is provided. The implementation of the software debouncer waits for the line to be stable for the debounce period before determining if a level change, and a corresponding edge event, has occurred. This provides maximum protection against glitches, but also introduces a debounce_period latency to edge events. The software debouncer is integrated with the edge detection as it utilises the line interrupt, and integration is simpler than getting the two to interwork. Where software debounce AND edge detection is required, the debouncer provides both. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 247 ++++++++++++++++++++++++++++++++++-- drivers/gpio/gpiolib.c | 3 + drivers/gpio/gpiolib.h | 4 + 3 files changed, 244 insertions(+), 10 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 25536aae3e18..73386fcc252d 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -22,6 +23,7 @@ #include #include #include +#include #include #include "gpiolib.h" @@ -415,6 +417,9 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) * events for the corresponding line request. This is drawn from the @req. * @line_seqno: the seqno for the current edge event in the sequence of * events for this line. + * @work: the worker that implements software debouncing + * @sw_debounced: flag indicating if the software debouncer is active + * @level: the current debounced physical level of the line */ struct line { struct gpio_desc *desc; @@ -431,7 +436,28 @@ struct line { */ u64 timestamp_ns; u32 req_seqno; + /* + * line_seqno is accessed by either edge_irq_thread() or + * debounce_work_func(), which are themselves mutually exclusive, + * so no additional protection is necessary. + */ u32 line_seqno; + /* + * -- debouncer specific fields -- + */ + struct delayed_work work; + /* + * sw_debounce is accessed by linereq_set_config(), which is the + * only setter, and linereq_get_values(), which can live with a + * slightly stale value. + */ + unsigned int sw_debounced; + /* + * level is accessed by debounce_work_func(), which is the only + * setter, and linereq_get_values() which can live with a slightly + * stale value. + */ + unsigned int level; }; /** @@ -572,6 +598,154 @@ static irqreturn_t edge_irq_handler(int irq, void *p) return IRQ_WAKE_THREAD; } +/* + * returns the current debounced logical value. + */ +static bool debounced_value(struct line *line) +{ + bool value; + + /* + * minor race - debouncer may be stopped here, so edge_detector_stop() + * must leave the value unchanged so the following will read the level + * from when the debouncer was last running. + */ + value = READ_ONCE(line->level); + + if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) + value = !value; + + return value; +} + +static irqreturn_t debounce_irq_handler(int irq, void *p) +{ + struct line *line = p; + + mod_delayed_work(system_wq, &line->work, + usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); + + return IRQ_HANDLED; +} + +static void debounce_work_func(struct work_struct *work) +{ + struct gpio_v2_line_event le; + struct line *line = container_of(work, struct line, work.work); + struct linereq *lr; + int level; + + level = gpiod_get_raw_value_cansleep(line->desc); + if (level < 0) { + pr_debug_ratelimited("debouncer failed to read line value\n"); + return; + } + + if (READ_ONCE(line->level) == level) + return; + + WRITE_ONCE(line->level, level); + + /* -- edge detection -- */ + if (!line->eflags) + return; + + /* switch from physical level to logical - if they differ */ + if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) + level = !level; + + /* ignore edges that are not being monitored */ + if (((line->eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) || + ((line->eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level)) + return; + + /* Do not leak kernel stack to userspace */ + memset(&le, 0, sizeof(le)); + + lr = line->req; + le.timestamp_ns = ktime_get_ns(); + le.offset = gpio_chip_hwgpio(line->desc); + line->line_seqno++; + le.line_seqno = line->line_seqno; + le.seqno = (lr->num_lines == 1) ? + le.line_seqno : atomic_inc_return(&lr->seqno); + + if (level) + /* Emit low-to-high event */ + le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; + else + /* Emit high-to-low event */ + le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; + + linereq_put_event(lr, &le); +} + +static int debounce_setup(struct line *line, + unsigned int debounce_period_us) +{ + unsigned long irqflags; + int ret, level, irq; + + /* try hardware */ + ret = gpiod_set_debounce(line->desc, debounce_period_us); + if (!ret) { + WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); + return ret; + } + if (ret != -ENOTSUPP) + return ret; + + if (debounce_period_us) { + /* setup software debounce */ + level = gpiod_get_raw_value_cansleep(line->desc); + if (level < 0) + return level; + + irq = gpiod_to_irq(line->desc); + if (irq < 0) + return -ENXIO; + + WRITE_ONCE(line->level, level); + irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; + ret = request_irq(irq, debounce_irq_handler, irqflags, + line->req->label, line); + if (ret) + return ret; + + WRITE_ONCE(line->sw_debounced, 1); + line->irq = irq; + } + return 0; +} + +static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc, + unsigned int line_idx) +{ + unsigned int i; + u64 mask = BIT_ULL(line_idx); + + for (i = 0; i < lc->num_attrs; i++) { + if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && + (lc->attrs[i].mask & mask)) + return true; + } + return false; +} + +static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc, + unsigned int line_idx) +{ + unsigned int i; + u64 mask = BIT_ULL(line_idx); + + for (i = 0; i < lc->num_attrs; i++) { + if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && + (lc->attrs[i].mask & mask)) + return lc->attrs[i].attr.debounce_period_us; + } + return 0; +} + static void edge_detector_stop(struct line *line) { if (line->irq) { @@ -579,12 +753,18 @@ static void edge_detector_stop(struct line *line) line->irq = 0; } + cancel_delayed_work_sync(&line->work); + WRITE_ONCE(line->sw_debounced, 0); line->eflags = 0; + /* do not change line->level - see comment in debounced_value() */ } static int edge_detector_setup(struct line *line, + struct gpio_v2_line_config *lc, + unsigned int line_idx, u64 eflags) { + u32 debounce_period_us; unsigned long irqflags = 0; int irq, ret; @@ -595,8 +775,16 @@ static int edge_detector_setup(struct line *line, return ret; } line->eflags = eflags; + if (gpio_v2_line_config_debounced(lc, line_idx)) { + debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); + ret = debounce_setup(line, debounce_period_us); + if (ret) + return ret; + WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); + } - if (!eflags) + /* detection disabled or sw debouncer will provide edge detection */ + if (!eflags || READ_ONCE(line->sw_debounced)) return 0; irq = gpiod_to_irq(line->desc); @@ -621,15 +809,31 @@ static int edge_detector_setup(struct line *line, return 0; } -static int edge_detector_update(struct line *line, u64 eflags, - bool polarity_change) +static int edge_detector_update(struct line *line, + struct gpio_v2_line_config *lc, + unsigned int line_idx, + u64 eflags, bool polarity_change) { - if ((line->eflags == eflags) && !polarity_change) + unsigned int debounce_period_us = + gpio_v2_line_config_debounce_period(lc, line_idx); + + if ((line->eflags == eflags) && !polarity_change && + (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us)) return 0; - edge_detector_stop(line); + /* sw debounced and still will be...*/ + if (debounce_period_us && READ_ONCE(line->sw_debounced)) { + line->eflags = eflags; + WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); + return 0; + } - return edge_detector_setup(line, eflags); + /* reconfiguring edge detection or sw debounce being disabled */ + if ((line->irq && !READ_ONCE(line->sw_debounced)) || + (!debounce_period_us && READ_ONCE(line->sw_debounced))) + edge_detector_stop(line); + + return edge_detector_setup(line, lc, line_idx, eflags); } static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, @@ -727,6 +931,11 @@ static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, ret = gpio_v2_line_flags_validate(flags); if (ret) return ret; + + /* debounce requires explicit input */ + if (gpio_v2_line_config_debounced(lc, i) && + !(flags & GPIO_V2_LINE_FLAG_INPUT)) + return -EINVAL; } return 0; } @@ -766,6 +975,7 @@ static long linereq_get_values(struct linereq *lr, void __user *ip) DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); struct gpio_desc **descs; unsigned int i, didx, num_get; + bool val; int ret; /* NOTE: It's ok to read values of output lines. */ @@ -804,7 +1014,11 @@ static long linereq_get_values(struct linereq *lr, void __user *ip) lv.bits = 0; for (didx = 0, i = 0; i < lr->num_lines; i++) { if (lv.mask & BIT_ULL(i)) { - if (test_bit(didx, vals)) + if (lr->lines[i].sw_debounced) + val = debounced_value(&lr->lines[i]); + else + val = test_bit(didx, vals); + if (val) lv.bits |= BIT_ULL(i); didx++; } @@ -908,7 +1122,7 @@ static long linereq_set_config_unlocked(struct linereq *lr, if (ret) return ret; - ret = edge_detector_update(&lr->lines[i], + ret = edge_detector_update(&lr->lines[i], lc, i, flags & GPIO_V2_LINE_EDGE_FLAGS, polarity_change); if (ret) @@ -1102,8 +1316,11 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) lr->gdev = gdev; get_device(&gdev->dev); - for (i = 0; i < ulr.num_lines; i++) + for (i = 0; i < ulr.num_lines; i++) { lr->lines[i].req = lr; + WRITE_ONCE(lr->lines[i].sw_debounced, 0); + INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func); + } /* Make sure this is terminated */ ulr.consumer[sizeof(ulr.consumer)-1] = '\0'; @@ -1164,7 +1381,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip) if (ret) goto out_free_linereq; - ret = edge_detector_setup(&lr->lines[i], + ret = edge_detector_setup(&lr->lines[i], lc, i, flags & GPIO_V2_LINE_EDGE_FLAGS); if (ret) goto out_free_linereq; @@ -1634,6 +1851,8 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, struct gpio_chip *gc = desc->gdev->chip; bool ok_for_pinctrl; unsigned long flags; + u32 debounce_period_us; + unsigned int num_attrs = 0; memset(info, 0, sizeof(*info)); info->offset = gpio_chip_hwgpio(desc); @@ -1694,6 +1913,14 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, if (test_bit(FLAG_EDGE_FALLING, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; + debounce_period_us = READ_ONCE(desc->debounce_period_us); + if (debounce_period_us) { + info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE; + info->attrs[num_attrs].debounce_period_us = debounce_period_us; + num_attrs++; + } + info->num_attrs = num_attrs; + spin_unlock_irqrestore(&gpio_lock, flags); } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index aa20481e9452..3cdf9effc13a 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2097,6 +2097,9 @@ static bool gpiod_free_commit(struct gpio_desc *desc) clear_bit(FLAG_IS_HOGGED, &desc->flags); #ifdef CONFIG_OF_DYNAMIC desc->hog = NULL; +#endif +#ifdef CONFIG_GPIO_CDEV + WRITE_ONCE(desc->debounce_period_us, 0); #endif ret = true; } diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 39b356160937..b674b5bb980e 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -124,6 +124,10 @@ struct gpio_desc { #ifdef CONFIG_OF_DYNAMIC struct device_node *hog; #endif +#ifdef CONFIG_GPIO_CDEV + /* debounce period in microseconds */ + unsigned int debounce_period_us; +#endif }; int gpiod_request(struct gpio_desc *desc, const char *label); From b234d233fe30c63c4e461b03e2884a6765c8e5b0 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:00 +0800 Subject: [PATCH 25/32] gpio: uapi: document uAPI v1 as deprecated Update uAPI documentation to deprecate v1 structs and ioctls. Signed-off-by: Kent Gibson Signed-off-by: Bartosz Golaszewski --- include/uapi/linux/gpio.h | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h index 5904f49399de..07865c601099 100644 --- a/include/uapi/linux/gpio.h +++ b/include/uapi/linux/gpio.h @@ -292,6 +292,9 @@ struct gpio_v2_line_event { /* * ABI v1 + * + * This version of the ABI is deprecated. + * Use the latest version of the ABI, defined above, instead. */ /* Informational flags */ @@ -315,6 +318,9 @@ struct gpio_v2_line_event { * @consumer: a functional name for the consumer of this GPIO line as set by * whatever is using it, will be empty if there is no current user but may * also be empty if the consumer doesn't set this up + * + * This struct is part of ABI v1 and is deprecated. + * Use struct gpio_v2_line_info instead. */ struct gpioline_info { __u32 line_offset; @@ -346,6 +352,9 @@ enum { * guarantee there are no implicit holes between it and subsequent members. * The 20-byte padding at the end makes sure we don't add any implicit padding * at the end of the structure on 64-bit architectures. + * + * This struct is part of ABI v1 and is deprecated. + * Use struct gpio_v2_line_info_changed instead. */ struct gpioline_info_changed { struct gpioline_info info; @@ -385,6 +394,9 @@ struct gpioline_info_changed { * @fd: if successful this field will contain a valid anonymous file handle * after a GPIO_GET_LINEHANDLE_IOCTL operation, zero or negative value * means error + * + * This struct is part of ABI v1 and is deprecated. + * Use struct gpio_v2_line_request instead. */ struct gpiohandle_request { __u32 lineoffsets[GPIOHANDLES_MAX]; @@ -404,6 +416,9 @@ struct gpiohandle_request { * this specifies the default output value, should be 0 (low) or * 1 (high), anything else than 0 or 1 will be interpreted as 1 (high) * @padding: reserved for future use and should be zero filled + * + * This struct is part of ABI v1 and is deprecated. + * Use struct gpio_v2_line_config instead. */ struct gpiohandle_config { __u32 flags; @@ -416,6 +431,9 @@ struct gpiohandle_config { * @values: when getting the state of lines this contains the current * state of a line, when setting the state of lines these should contain * the desired target state + * + * This struct is part of ABI v1 and is deprecated. + * Use struct gpio_v2_line_values instead. */ struct gpiohandle_data { __u8 values[GPIOHANDLES_MAX]; @@ -439,6 +457,9 @@ struct gpiohandle_data { * @fd: if successful this field will contain a valid anonymous file handle * after a GPIO_GET_LINEEVENT_IOCTL operation, zero or negative value * means error + * + * This struct is part of ABI v1 and is deprecated. + * Use struct gpio_v2_line_request instead. */ struct gpioevent_request { __u32 lineoffset; @@ -458,6 +479,9 @@ struct gpioevent_request { * struct gpioevent_data - The actual event being pushed to userspace * @timestamp: best estimate of time of event occurrence, in nanoseconds * @id: event identifier + * + * This struct is part of ABI v1 and is deprecated. + * Use struct gpio_v2_line_event instead. */ struct gpioevent_data { __u64 timestamp; @@ -482,6 +506,8 @@ struct gpioevent_data { /* * v1 ioctl()s + * + * These ioctl()s are deprecated. Use the v2 equivalent instead. */ #define GPIO_GET_LINEINFO_IOCTL _IOWR(0xB4, 0x02, struct gpioline_info) #define GPIO_GET_LINEHANDLE_IOCTL _IOWR(0xB4, 0x03, struct gpiohandle_request) From 3c333c47041c905b81860478d2d8c0c3e8623b40 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:01 +0800 Subject: [PATCH 26/32] tools: gpio: port lsgpio to v2 uAPI Port the lsgpio tool to the latest GPIO uAPI. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- tools/gpio/lsgpio.c | 60 ++++++++++++++++++++++++++++----------------- 1 file changed, 38 insertions(+), 22 deletions(-) diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c index b08d7a5e779b..5a05a454d0c9 100644 --- a/tools/gpio/lsgpio.c +++ b/tools/gpio/lsgpio.c @@ -25,57 +25,73 @@ struct gpio_flag { char *name; - unsigned long mask; + unsigned long long mask; }; struct gpio_flag flagnames[] = { { - .name = "kernel", - .mask = GPIOLINE_FLAG_KERNEL, + .name = "used", + .mask = GPIO_V2_LINE_FLAG_USED, + }, + { + .name = "input", + .mask = GPIO_V2_LINE_FLAG_INPUT, }, { .name = "output", - .mask = GPIOLINE_FLAG_IS_OUT, + .mask = GPIO_V2_LINE_FLAG_OUTPUT, }, { .name = "active-low", - .mask = GPIOLINE_FLAG_ACTIVE_LOW, + .mask = GPIO_V2_LINE_FLAG_ACTIVE_LOW, }, { .name = "open-drain", - .mask = GPIOLINE_FLAG_OPEN_DRAIN, + .mask = GPIO_V2_LINE_FLAG_OPEN_DRAIN, }, { .name = "open-source", - .mask = GPIOLINE_FLAG_OPEN_SOURCE, + .mask = GPIO_V2_LINE_FLAG_OPEN_SOURCE, }, { .name = "pull-up", - .mask = GPIOLINE_FLAG_BIAS_PULL_UP, + .mask = GPIO_V2_LINE_FLAG_BIAS_PULL_UP, }, { .name = "pull-down", - .mask = GPIOLINE_FLAG_BIAS_PULL_DOWN, + .mask = GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN, }, { .name = "bias-disabled", - .mask = GPIOLINE_FLAG_BIAS_DISABLE, + .mask = GPIO_V2_LINE_FLAG_BIAS_DISABLED, }, }; -void print_flags(unsigned long flags) +static void print_attributes(struct gpio_v2_line_info *info) { int i; - int printed = 0; + const char *field_format = "%s"; for (i = 0; i < ARRAY_SIZE(flagnames); i++) { - if (flags & flagnames[i].mask) { - if (printed) - fprintf(stdout, " "); - fprintf(stdout, "%s", flagnames[i].name); - printed++; + if (info->flags & flagnames[i].mask) { + fprintf(stdout, field_format, flagnames[i].name); + field_format = ", %s"; } } + + if ((info->flags & GPIO_V2_LINE_FLAG_EDGE_RISING) && + (info->flags & GPIO_V2_LINE_FLAG_EDGE_FALLING)) + fprintf(stdout, field_format, "both-edges"); + else if (info->flags & GPIO_V2_LINE_FLAG_EDGE_RISING) + fprintf(stdout, field_format, "rising-edge"); + else if (info->flags & GPIO_V2_LINE_FLAG_EDGE_FALLING) + fprintf(stdout, field_format, "falling-edge"); + + for (i = 0; i < info->num_attrs; i++) { + if (info->attrs[i].id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) + fprintf(stdout, ", debounce_period=%dusec", + info->attrs[0].debounce_period_us); + } } int list_device(const char *device_name) @@ -109,18 +125,18 @@ int list_device(const char *device_name) /* Loop over the lines and print info */ for (i = 0; i < cinfo.lines; i++) { - struct gpioline_info linfo; + struct gpio_v2_line_info linfo; memset(&linfo, 0, sizeof(linfo)); - linfo.line_offset = i; + linfo.offset = i; - ret = ioctl(fd, GPIO_GET_LINEINFO_IOCTL, &linfo); + ret = ioctl(fd, GPIO_V2_GET_LINEINFO_IOCTL, &linfo); if (ret == -1) { ret = -errno; perror("Failed to issue LINEINFO IOCTL\n"); goto exit_close_error; } - fprintf(stdout, "\tline %2d:", linfo.line_offset); + fprintf(stdout, "\tline %2d:", linfo.offset); if (linfo.name[0]) fprintf(stdout, " \"%s\"", linfo.name); else @@ -131,7 +147,7 @@ int list_device(const char *device_name) fprintf(stdout, " unused"); if (linfo.flags) { fprintf(stdout, " ["); - print_flags(linfo.flags); + print_attributes(&linfo); fprintf(stdout, "]"); } fprintf(stdout, "\n"); From e86a863b337c50713b674007f74dc1854701eb93 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:02 +0800 Subject: [PATCH 27/32] tools: gpio: port gpio-watch to v2 uAPI Port the gpio-watch tool to the latest GPIO uAPI. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- tools/gpio/gpio-watch.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/gpio/gpio-watch.c b/tools/gpio/gpio-watch.c index 5cea24fddfa7..f229ec62301b 100644 --- a/tools/gpio/gpio-watch.c +++ b/tools/gpio/gpio-watch.c @@ -21,8 +21,8 @@ int main(int argc, char **argv) { - struct gpioline_info_changed chg; - struct gpioline_info req; + struct gpio_v2_line_info_changed chg; + struct gpio_v2_line_info req; struct pollfd pfd; int fd, i, j, ret; char *event, *end; @@ -40,11 +40,11 @@ int main(int argc, char **argv) for (i = 0, j = 2; i < argc - 2; i++, j++) { memset(&req, 0, sizeof(req)); - req.line_offset = strtoul(argv[j], &end, 0); + req.offset = strtoul(argv[j], &end, 0); if (*end != '\0') goto err_usage; - ret = ioctl(fd, GPIO_GET_LINEINFO_WATCH_IOCTL, &req); + ret = ioctl(fd, GPIO_V2_GET_LINEINFO_WATCH_IOCTL, &req); if (ret) { perror("unable to set up line watch"); return EXIT_FAILURE; @@ -71,13 +71,13 @@ int main(int argc, char **argv) } switch (chg.event_type) { - case GPIOLINE_CHANGED_REQUESTED: + case GPIO_V2_LINE_CHANGED_REQUESTED: event = "requested"; break; - case GPIOLINE_CHANGED_RELEASED: + case GPIO_V2_LINE_CHANGED_RELEASED: event = "released"; break; - case GPIOLINE_CHANGED_CONFIG: + case GPIO_V2_LINE_CHANGED_CONFIG: event = "config changed"; break; default: @@ -87,7 +87,7 @@ int main(int argc, char **argv) } printf("line %u: %s at %llu\n", - chg.info.line_offset, event, chg.timestamp); + chg.info.offset, event, chg.timestamp_ns); } } From ed60aee0edcda1fabc39ab27c9650fa172f461b4 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:03 +0800 Subject: [PATCH 28/32] tools: gpio: rename nlines to num_lines Rename nlines to num_lines to be consistent with other usage for fields describing the number of entries in an array. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- tools/gpio/gpio-hammer.c | 26 +++++++++++++------------- tools/gpio/gpio-utils.c | 20 ++++++++++---------- tools/gpio/gpio-utils.h | 6 +++--- 3 files changed, 26 insertions(+), 26 deletions(-) diff --git a/tools/gpio/gpio-hammer.c b/tools/gpio/gpio-hammer.c index 9fd926e8cb52..a2c7577fad5c 100644 --- a/tools/gpio/gpio-hammer.c +++ b/tools/gpio/gpio-hammer.c @@ -22,7 +22,7 @@ #include #include "gpio-utils.h" -int hammer_device(const char *device_name, unsigned int *lines, int nlines, +int hammer_device(const char *device_name, unsigned int *lines, int num_lines, unsigned int loops) { struct gpiohandle_data data; @@ -33,7 +33,7 @@ int hammer_device(const char *device_name, unsigned int *lines, int nlines, unsigned int iteration = 0; memset(&data.values, 0, sizeof(data.values)); - ret = gpiotools_request_linehandle(device_name, lines, nlines, + ret = gpiotools_request_linehandle(device_name, lines, num_lines, GPIOHANDLE_REQUEST_OUTPUT, &data, "gpio-hammer"); if (ret < 0) @@ -46,15 +46,15 @@ int hammer_device(const char *device_name, unsigned int *lines, int nlines, goto exit_close_error; fprintf(stdout, "Hammer lines ["); - for (i = 0; i < nlines; i++) { + for (i = 0; i < num_lines; i++) { fprintf(stdout, "%d", lines[i]); - if (i != (nlines - 1)) + if (i != (num_lines - 1)) fprintf(stdout, ", "); } fprintf(stdout, "] on %s, initial states: [", device_name); - for (i = 0; i < nlines; i++) { + for (i = 0; i < num_lines; i++) { fprintf(stdout, "%d", data.values[i]); - if (i != (nlines - 1)) + if (i != (num_lines - 1)) fprintf(stdout, ", "); } fprintf(stdout, "]\n"); @@ -63,7 +63,7 @@ int hammer_device(const char *device_name, unsigned int *lines, int nlines, j = 0; while (1) { /* Invert all lines so we blink */ - for (i = 0; i < nlines; i++) + for (i = 0; i < num_lines; i++) data.values[i] = !data.values[i]; ret = gpiotools_set_values(fd, &data); @@ -81,9 +81,9 @@ int hammer_device(const char *device_name, unsigned int *lines, int nlines, j = 0; fprintf(stdout, "["); - for (i = 0; i < nlines; i++) { + for (i = 0; i < num_lines; i++) { fprintf(stdout, "%d: %d", lines[i], data.values[i]); - if (i != (nlines - 1)) + if (i != (num_lines - 1)) fprintf(stdout, ", "); } fprintf(stdout, "]\r"); @@ -121,7 +121,7 @@ int main(int argc, char **argv) const char *device_name = NULL; unsigned int lines[GPIOHANDLES_MAX]; unsigned int loops = 0; - int nlines; + int num_lines; int c; int i; @@ -158,11 +158,11 @@ int main(int argc, char **argv) return -1; } - nlines = i; + num_lines = i; - if (!device_name || !nlines) { + if (!device_name || !num_lines) { print_usage(); return -1; } - return hammer_device(device_name, lines, nlines, loops); + return hammer_device(device_name, lines, num_lines, loops); } diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c index 16a5d9cb9da2..d527980bcb94 100644 --- a/tools/gpio/gpio-utils.c +++ b/tools/gpio/gpio-utils.c @@ -38,7 +38,7 @@ * such as "gpiochip0" * @lines: An array desired lines, specified by offset * index for the associated GPIO device. - * @nline: The number of lines to request. + * @num_lines: The number of lines to request. * @flag: The new flag for requsted gpio. Reference * "linux/gpio.h" for the meaning of flag. * @data: Default value will be set to gpio when flag is @@ -56,7 +56,7 @@ * On failure return the errno. */ int gpiotools_request_linehandle(const char *device_name, unsigned int *lines, - unsigned int nlines, unsigned int flag, + unsigned int num_lines, unsigned int flag, struct gpiohandle_data *data, const char *consumer_label) { @@ -78,12 +78,12 @@ int gpiotools_request_linehandle(const char *device_name, unsigned int *lines, goto exit_free_name; } - for (i = 0; i < nlines; i++) + for (i = 0; i < num_lines; i++) req.lineoffsets[i] = lines[i]; req.flags = flag; strcpy(req.consumer_label, consumer_label); - req.lines = nlines; + req.lines = num_lines; if (flag & GPIOHANDLE_REQUEST_OUTPUT) memcpy(req.default_values, data, sizeof(req.default_values)); @@ -194,20 +194,20 @@ int gpiotools_get(const char *device_name, unsigned int line) * such as "gpiochip0". * @lines: An array desired lines, specified by offset * index for the associated GPIO device. - * @nline: The number of lines to request. + * @num_lines: The number of lines to request. * @data: The array of values get from gpiochip. * * Return: On success return 0; * On failure return the errno. */ int gpiotools_gets(const char *device_name, unsigned int *lines, - unsigned int nlines, struct gpiohandle_data *data) + unsigned int num_lines, struct gpiohandle_data *data) { int fd; int ret; int ret_close; - ret = gpiotools_request_linehandle(device_name, lines, nlines, + ret = gpiotools_request_linehandle(device_name, lines, num_lines, GPIOHANDLE_REQUEST_INPUT, data, CONSUMER); if (ret < 0) @@ -245,7 +245,7 @@ int gpiotools_set(const char *device_name, unsigned int line, * such as "gpiochip0". * @lines: An array desired lines, specified by offset * index for the associated GPIO device. - * @nline: The number of lines to request. + * @num_lines: The number of lines to request. * @data: The array of values set to gpiochip, must be * 0(low) or 1(high). * @@ -253,11 +253,11 @@ int gpiotools_set(const char *device_name, unsigned int line, * On failure return the errno. */ int gpiotools_sets(const char *device_name, unsigned int *lines, - unsigned int nlines, struct gpiohandle_data *data) + unsigned int num_lines, struct gpiohandle_data *data) { int ret; - ret = gpiotools_request_linehandle(device_name, lines, nlines, + ret = gpiotools_request_linehandle(device_name, lines, num_lines, GPIOHANDLE_REQUEST_OUTPUT, data, CONSUMER); if (ret < 0) diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h index cf37f13f3dcb..324729577865 100644 --- a/tools/gpio/gpio-utils.h +++ b/tools/gpio/gpio-utils.h @@ -23,7 +23,7 @@ static inline int check_prefix(const char *str, const char *prefix) } int gpiotools_request_linehandle(const char *device_name, unsigned int *lines, - unsigned int nlines, unsigned int flag, + unsigned int num_lines, unsigned int flag, struct gpiohandle_data *data, const char *consumer_label); int gpiotools_set_values(const int fd, struct gpiohandle_data *data); @@ -32,10 +32,10 @@ int gpiotools_release_linehandle(const int fd); int gpiotools_get(const char *device_name, unsigned int line); int gpiotools_gets(const char *device_name, unsigned int *lines, - unsigned int nlines, struct gpiohandle_data *data); + unsigned int num_lines, struct gpiohandle_data *data); int gpiotools_set(const char *device_name, unsigned int line, unsigned int value); int gpiotools_sets(const char *device_name, unsigned int *lines, - unsigned int nlines, struct gpiohandle_data *data); + unsigned int num_lines, struct gpiohandle_data *data); #endif /* _GPIO_UTILS_H_ */ From 7ff6d1d25a9ea3a03f795d383889ac34fbc601d5 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:04 +0800 Subject: [PATCH 29/32] tools: gpio: port gpio-hammer to v2 uAPI Port the gpio-hammer tool to the latest GPIO uAPI. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- tools/gpio/gpio-hammer.c | 32 +++++--- tools/gpio/gpio-utils.c | 164 ++++++++++++++++++++++++++++++++------- tools/gpio/gpio-utils.h | 46 ++++++++++- 3 files changed, 197 insertions(+), 45 deletions(-) diff --git a/tools/gpio/gpio-hammer.c b/tools/gpio/gpio-hammer.c index a2c7577fad5c..54fdf59dd320 100644 --- a/tools/gpio/gpio-hammer.c +++ b/tools/gpio/gpio-hammer.c @@ -25,23 +25,30 @@ int hammer_device(const char *device_name, unsigned int *lines, int num_lines, unsigned int loops) { - struct gpiohandle_data data; + struct gpio_v2_line_values values; + struct gpio_v2_line_config config; char swirr[] = "-\\|/"; int fd; int ret; int i, j; unsigned int iteration = 0; - memset(&data.values, 0, sizeof(data.values)); - ret = gpiotools_request_linehandle(device_name, lines, num_lines, - GPIOHANDLE_REQUEST_OUTPUT, &data, - "gpio-hammer"); + memset(&config, 0, sizeof(config)); + config.flags = GPIO_V2_LINE_FLAG_OUTPUT; + + ret = gpiotools_request_line(device_name, lines, num_lines, + &config, "gpio-hammer"); if (ret < 0) goto exit_error; else fd = ret; - ret = gpiotools_get_values(fd, &data); + values.mask = 0; + values.bits = 0; + for (i = 0; i < num_lines; i++) + gpiotools_set_bit(&values.mask, i); + + ret = gpiotools_get_values(fd, &values); if (ret < 0) goto exit_close_error; @@ -53,7 +60,7 @@ int hammer_device(const char *device_name, unsigned int *lines, int num_lines, } fprintf(stdout, "] on %s, initial states: [", device_name); for (i = 0; i < num_lines; i++) { - fprintf(stdout, "%d", data.values[i]); + fprintf(stdout, "%d", gpiotools_test_bit(values.bits, i)); if (i != (num_lines - 1)) fprintf(stdout, ", "); } @@ -64,14 +71,14 @@ int hammer_device(const char *device_name, unsigned int *lines, int num_lines, while (1) { /* Invert all lines so we blink */ for (i = 0; i < num_lines; i++) - data.values[i] = !data.values[i]; + gpiotools_change_bit(&values.bits, i); - ret = gpiotools_set_values(fd, &data); + ret = gpiotools_set_values(fd, &values); if (ret < 0) goto exit_close_error; /* Re-read values to get status */ - ret = gpiotools_get_values(fd, &data); + ret = gpiotools_get_values(fd, &values); if (ret < 0) goto exit_close_error; @@ -82,7 +89,8 @@ int hammer_device(const char *device_name, unsigned int *lines, int num_lines, fprintf(stdout, "["); for (i = 0; i < num_lines; i++) { - fprintf(stdout, "%d: %d", lines[i], data.values[i]); + fprintf(stdout, "%d: %d", lines[i], + gpiotools_test_bit(values.bits, i)); if (i != (num_lines - 1)) fprintf(stdout, ", "); } @@ -97,7 +105,7 @@ int hammer_device(const char *device_name, unsigned int *lines, int num_lines, ret = 0; exit_close_error: - gpiotools_release_linehandle(fd); + gpiotools_release_line(fd); exit_error: return ret; } diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c index d527980bcb94..37187e056c8b 100644 --- a/tools/gpio/gpio-utils.c +++ b/tools/gpio/gpio-utils.c @@ -100,20 +100,87 @@ int gpiotools_request_linehandle(const char *device_name, unsigned int *lines, free(chrdev_name); return ret < 0 ? ret : req.fd; } + +/** + * gpiotools_request_line() - request gpio lines in a gpiochip + * @device_name: The name of gpiochip without prefix "/dev/", + * such as "gpiochip0" + * @lines: An array desired lines, specified by offset + * index for the associated GPIO device. + * @num_lines: The number of lines to request. + * @config: The new config for requested gpio. Reference + * "linux/gpio.h" for config details. + * @consumer: The name of consumer, such as "sysfs", + * "powerkey". This is useful for other users to + * know who is using. + * + * Request gpio lines through the ioctl provided by chardev. User + * could call gpiotools_set_values() and gpiotools_get_values() to + * read and write respectively through the returned fd. Call + * gpiotools_release_line() to release these lines after that. + * + * Return: On success return the fd; + * On failure return the errno. + */ +int gpiotools_request_line(const char *device_name, unsigned int *lines, + unsigned int num_lines, + struct gpio_v2_line_config *config, + const char *consumer) +{ + struct gpio_v2_line_request req; + char *chrdev_name; + int fd; + int i; + int ret; + + ret = asprintf(&chrdev_name, "/dev/%s", device_name); + if (ret < 0) + return -ENOMEM; + + fd = open(chrdev_name, 0); + if (fd == -1) { + ret = -errno; + fprintf(stderr, "Failed to open %s, %s\n", + chrdev_name, strerror(errno)); + goto exit_free_name; + } + + memset(&req, 0, sizeof(req)); + for (i = 0; i < num_lines; i++) + req.offsets[i] = lines[i]; + + req.config = *config; + strcpy(req.consumer, consumer); + req.num_lines = num_lines; + + ret = ioctl(fd, GPIO_V2_GET_LINE_IOCTL, &req); + if (ret == -1) { + ret = -errno; + fprintf(stderr, "Failed to issue %s (%d), %s\n", + "GPIO_GET_LINE_IOCTL", ret, strerror(errno)); + } + + if (close(fd) == -1) + perror("Failed to close GPIO character device file"); +exit_free_name: + free(chrdev_name); + return ret < 0 ? ret : req.fd; +} + /** * gpiotools_set_values(): Set the value of gpio(s) * @fd: The fd returned by - * gpiotools_request_linehandle(). - * @data: The array of values want to set. + * gpiotools_request_line(). + * @values: The array of values want to set. * * Return: On success return 0; * On failure return the errno. */ -int gpiotools_set_values(const int fd, struct gpiohandle_data *data) +int gpiotools_set_values(const int fd, struct gpio_v2_line_values *values) { int ret; - ret = ioctl(fd, GPIOHANDLE_SET_LINE_VALUES_IOCTL, data); + ret = ioctl(fd, GPIO_V2_LINE_SET_VALUES_IOCTL, values); if (ret == -1) { ret = -errno; fprintf(stderr, "Failed to issue %s (%d), %s\n", @@ -127,17 +194,17 @@ int gpiotools_set_values(const int fd, struct gpiohandle_data *data) /** * gpiotools_get_values(): Get the value of gpio(s) * @fd: The fd returned by - * gpiotools_request_linehandle(). - * @data: The array of values get from hardware. + * gpiotools_request_line(). + * @values: The array of values get from hardware. * * Return: On success return 0; * On failure return the errno. */ -int gpiotools_get_values(const int fd, struct gpiohandle_data *data) +int gpiotools_get_values(const int fd, struct gpio_v2_line_values *values) { int ret; - ret = ioctl(fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, data); + ret = ioctl(fd, GPIO_V2_LINE_GET_VALUES_IOCTL, values); if (ret == -1) { ret = -errno; fprintf(stderr, "Failed to issue %s (%d), %s\n", @@ -169,6 +236,27 @@ int gpiotools_release_linehandle(const int fd) return ret; } +/** + * gpiotools_release_line(): Release the line(s) of gpiochip + * @fd: The fd returned by + * gpiotools_request_line(). + * + * Return: On success return 0; + * On failure return the errno. + */ +int gpiotools_release_line(const int fd) +{ + int ret; + + ret = close(fd); + if (ret == -1) { + perror("Failed to close GPIO LINE device file"); + ret = -errno; + } + + return ret; +} + /** * gpiotools_get(): Get value from specific line * @device_name: The name of gpiochip without prefix "/dev/", @@ -180,11 +268,14 @@ int gpiotools_release_linehandle(const int fd) */ int gpiotools_get(const char *device_name, unsigned int line) { - struct gpiohandle_data data; + int ret; + unsigned int value; unsigned int lines[] = {line}; - gpiotools_gets(device_name, lines, 1, &data); - return data.values[0]; + ret = gpiotools_gets(device_name, lines, 1, &value); + if (ret) + return ret; + return value; } @@ -195,27 +286,35 @@ int gpiotools_get(const char *device_name, unsigned int line) * @lines: An array desired lines, specified by offset * index for the associated GPIO device. * @num_lines: The number of lines to request. - * @data: The array of values get from gpiochip. + * @values: The array of values get from gpiochip. * * Return: On success return 0; * On failure return the errno. */ int gpiotools_gets(const char *device_name, unsigned int *lines, - unsigned int num_lines, struct gpiohandle_data *data) + unsigned int num_lines, unsigned int *values) { - int fd; + int fd, i; int ret; int ret_close; + struct gpio_v2_line_config config; + struct gpio_v2_line_values lv; - ret = gpiotools_request_linehandle(device_name, lines, num_lines, - GPIOHANDLE_REQUEST_INPUT, data, - CONSUMER); + memset(&config, 0, sizeof(config)); + config.flags = GPIO_V2_LINE_FLAG_INPUT; + ret = gpiotools_request_line(device_name, lines, num_lines, + &config, CONSUMER); if (ret < 0) return ret; fd = ret; - ret = gpiotools_get_values(fd, data); - ret_close = gpiotools_release_linehandle(fd); + for (i = 0; i < num_lines; i++) + gpiotools_set_bit(&lv.mask, i); + ret = gpiotools_get_values(fd, &lv); + if (!ret) + for (i = 0; i < num_lines; i++) + values[i] = gpiotools_test_bit(lv.bits, i); + ret_close = gpiotools_release_line(fd); return ret < 0 ? ret : ret_close; } @@ -232,11 +331,9 @@ int gpiotools_gets(const char *device_name, unsigned int *lines, int gpiotools_set(const char *device_name, unsigned int line, unsigned int value) { - struct gpiohandle_data data; unsigned int lines[] = {line}; - data.values[0] = value; - return gpiotools_sets(device_name, lines, 1, &data); + return gpiotools_sets(device_name, lines, 1, &value); } /** @@ -246,22 +343,31 @@ int gpiotools_set(const char *device_name, unsigned int line, * @lines: An array desired lines, specified by offset * index for the associated GPIO device. * @num_lines: The number of lines to request. - * @data: The array of values set to gpiochip, must be + * @value: The array of values set to gpiochip, must be * 0(low) or 1(high). * * Return: On success return 0; * On failure return the errno. */ int gpiotools_sets(const char *device_name, unsigned int *lines, - unsigned int num_lines, struct gpiohandle_data *data) + unsigned int num_lines, unsigned int *values) { - int ret; + int ret, i; + struct gpio_v2_line_config config; - ret = gpiotools_request_linehandle(device_name, lines, num_lines, - GPIOHANDLE_REQUEST_OUTPUT, data, - CONSUMER); + memset(&config, 0, sizeof(config)); + config.flags = GPIO_V2_LINE_FLAG_OUTPUT; + config.num_attrs = 1; + config.attrs[0].attr.id = GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES; + for (i = 0; i < num_lines; i++) { + gpiotools_set_bit(&config.attrs[0].mask, i); + gpiotools_assign_bit(&config.attrs[0].attr.values, + i, values[i]); + } + ret = gpiotools_request_line(device_name, lines, num_lines, + &config, CONSUMER); if (ret < 0) return ret; - return gpiotools_release_linehandle(ret); + return gpiotools_release_line(ret); } diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h index 324729577865..6c69a9f1c253 100644 --- a/tools/gpio/gpio-utils.h +++ b/tools/gpio/gpio-utils.h @@ -12,7 +12,9 @@ #ifndef _GPIO_UTILS_H_ #define _GPIO_UTILS_H_ +#include #include +#include #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) @@ -26,16 +28,52 @@ int gpiotools_request_linehandle(const char *device_name, unsigned int *lines, unsigned int num_lines, unsigned int flag, struct gpiohandle_data *data, const char *consumer_label); -int gpiotools_set_values(const int fd, struct gpiohandle_data *data); -int gpiotools_get_values(const int fd, struct gpiohandle_data *data); int gpiotools_release_linehandle(const int fd); +int gpiotools_request_line(const char *device_name, + unsigned int *lines, + unsigned int num_lines, + struct gpio_v2_line_config *config, + const char *consumer); +int gpiotools_set_values(const int fd, struct gpio_v2_line_values *values); +int gpiotools_get_values(const int fd, struct gpio_v2_line_values *values); +int gpiotools_release_line(const int fd); + int gpiotools_get(const char *device_name, unsigned int line); int gpiotools_gets(const char *device_name, unsigned int *lines, - unsigned int num_lines, struct gpiohandle_data *data); + unsigned int num_lines, unsigned int *values); int gpiotools_set(const char *device_name, unsigned int line, unsigned int value); int gpiotools_sets(const char *device_name, unsigned int *lines, - unsigned int num_lines, struct gpiohandle_data *data); + unsigned int num_lines, unsigned int *values); + +/* helper functions for gpio_v2_line_values bits */ +static inline void gpiotools_set_bit(__u64 *b, int n) +{ + *b |= _BITULL(n); +} + +static inline void gpiotools_change_bit(__u64 *b, int n) +{ + *b ^= _BITULL(n); +} + +static inline void gpiotools_clear_bit(__u64 *b, int n) +{ + *b &= ~_BITULL(n); +} + +static inline int gpiotools_test_bit(__u64 b, int n) +{ + return !!(b & _BITULL(n)); +} + +static inline void gpiotools_assign_bit(__u64 *b, int n, bool value) +{ + if (value) + gpiotools_set_bit(b, n); + else + gpiotools_clear_bit(b, n); +} #endif /* _GPIO_UTILS_H_ */ From 0acda979df8d065f9cb16bbc723723b036697e57 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:05 +0800 Subject: [PATCH 30/32] tools: gpio: port gpio-event-mon to v2 uAPI Port the gpio-event-mon tool to the latest GPIO uAPI. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- tools/gpio/gpio-event-mon.c | 91 +++++++++++++++++++------------------ 1 file changed, 47 insertions(+), 44 deletions(-) diff --git a/tools/gpio/gpio-event-mon.c b/tools/gpio/gpio-event-mon.c index 1a303a81aeef..b230af889f26 100644 --- a/tools/gpio/gpio-event-mon.c +++ b/tools/gpio/gpio-event-mon.c @@ -23,17 +23,16 @@ #include #include #include +#include "gpio-utils.h" int monitor_device(const char *device_name, unsigned int line, - uint32_t handleflags, - uint32_t eventflags, + struct gpio_v2_line_config *config, unsigned int loops) { - struct gpioevent_request req; - struct gpiohandle_data data; + struct gpio_v2_line_values values; char *chrdev_name; - int fd; + int cfd, lfd; int ret; int i = 0; @@ -41,44 +40,39 @@ int monitor_device(const char *device_name, if (ret < 0) return -ENOMEM; - fd = open(chrdev_name, 0); - if (fd == -1) { + cfd = open(chrdev_name, 0); + if (cfd == -1) { ret = -errno; fprintf(stderr, "Failed to open %s\n", chrdev_name); goto exit_free_name; } - req.lineoffset = line; - req.handleflags = handleflags; - req.eventflags = eventflags; - strcpy(req.consumer_label, "gpio-event-mon"); - - ret = ioctl(fd, GPIO_GET_LINEEVENT_IOCTL, &req); - if (ret == -1) { - ret = -errno; - fprintf(stderr, "Failed to issue GET EVENT " - "IOCTL (%d)\n", - ret); - goto exit_close_error; - } + ret = gpiotools_request_line(device_name, &line, 1, config, + "gpio-event-mon"); + if (ret < 0) + goto exit_device_close; + else + lfd = ret; /* Read initial states */ - ret = ioctl(req.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data); - if (ret == -1) { - ret = -errno; - fprintf(stderr, "Failed to issue GPIOHANDLE GET LINE " - "VALUES IOCTL (%d)\n", + values.mask = 1; + values.bits = 0; + ret = gpiotools_get_values(lfd, &values); + if (ret < 0) { + fprintf(stderr, + "Failed to issue GPIO LINE GET VALUES IOCTL (%d)\n", ret); - goto exit_close_error; + goto exit_line_close; } fprintf(stdout, "Monitoring line %d on %s\n", line, device_name); - fprintf(stdout, "Initial line value: %d\n", data.values[0]); + fprintf(stdout, "Initial line value: %d\n", + gpiotools_test_bit(values.bits, 0)); while (1) { - struct gpioevent_data event; + struct gpio_v2_line_event event; - ret = read(req.fd, &event, sizeof(event)); + ret = read(lfd, &event, sizeof(event)); if (ret == -1) { if (errno == -EAGAIN) { fprintf(stderr, "nothing available\n"); @@ -96,12 +90,14 @@ int monitor_device(const char *device_name, ret = -EIO; break; } - fprintf(stdout, "GPIO EVENT %llu: ", event.timestamp); + fprintf(stdout, "GPIO EVENT at %llu on line %d (%d|%d) ", + event.timestamp_ns, event.offset, event.line_seqno, + event.seqno); switch (event.id) { - case GPIOEVENT_EVENT_RISING_EDGE: + case GPIO_V2_LINE_EVENT_RISING_EDGE: fprintf(stdout, "rising edge"); break; - case GPIOEVENT_EVENT_FALLING_EDGE: + case GPIO_V2_LINE_EVENT_FALLING_EDGE: fprintf(stdout, "falling edge"); break; default: @@ -114,8 +110,11 @@ int monitor_device(const char *device_name, break; } -exit_close_error: - if (close(fd) == -1) +exit_line_close: + if (close(lfd) == -1) + perror("Failed to close line file"); +exit_device_close: + if (close(cfd) == -1) perror("Failed to close GPIO character device file"); exit_free_name: free(chrdev_name); @@ -140,15 +139,20 @@ void print_usage(void) ); } +#define EDGE_FLAGS \ + (GPIO_V2_LINE_FLAG_EDGE_RISING | \ + GPIO_V2_LINE_FLAG_EDGE_FALLING) + int main(int argc, char **argv) { const char *device_name = NULL; unsigned int line = -1; unsigned int loops = 0; - uint32_t handleflags = GPIOHANDLE_REQUEST_INPUT; - uint32_t eventflags = 0; + struct gpio_v2_line_config config; int c; + memset(&config, 0, sizeof(config)); + config.flags = GPIO_V2_LINE_FLAG_INPUT; while ((c = getopt(argc, argv, "c:n:o:dsrf?")) != -1) { switch (c) { case 'c': @@ -161,16 +165,16 @@ int main(int argc, char **argv) line = strtoul(optarg, NULL, 10); break; case 'd': - handleflags |= GPIOHANDLE_REQUEST_OPEN_DRAIN; + config.flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; break; case 's': - handleflags |= GPIOHANDLE_REQUEST_OPEN_SOURCE; + config.flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE; break; case 'r': - eventflags |= GPIOEVENT_REQUEST_RISING_EDGE; + config.flags |= GPIO_V2_LINE_FLAG_EDGE_RISING; break; case 'f': - eventflags |= GPIOEVENT_REQUEST_FALLING_EDGE; + config.flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; break; case '?': print_usage(); @@ -182,11 +186,10 @@ int main(int argc, char **argv) print_usage(); return -1; } - if (!eventflags) { + if (!(config.flags & EDGE_FLAGS)) { printf("No flags specified, listening on both rising and " "falling edges\n"); - eventflags = GPIOEVENT_REQUEST_BOTH_EDGES; + config.flags |= EDGE_FLAGS; } - return monitor_device(device_name, line, handleflags, - eventflags, loops); + return monitor_device(device_name, line, &config, loops); } From 62757c32d5db33fa3abb7b7b88201f9b4ecbc85b Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:06 +0800 Subject: [PATCH 31/32] tools: gpio: add multi-line monitoring to gpio-event-mon Extend gpio-event-mon to support monitoring multiple lines. This would require multiple lineevent requests to implement using uAPI v1, but can be performed with a single line request using uAPI v2. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- tools/gpio/gpio-event-mon.c | 45 ++++++++++++++++++++++++++++--------- 1 file changed, 34 insertions(+), 11 deletions(-) diff --git a/tools/gpio/gpio-event-mon.c b/tools/gpio/gpio-event-mon.c index b230af889f26..0c34f18f511c 100644 --- a/tools/gpio/gpio-event-mon.c +++ b/tools/gpio/gpio-event-mon.c @@ -26,7 +26,8 @@ #include "gpio-utils.h" int monitor_device(const char *device_name, - unsigned int line, + unsigned int *lines, + unsigned int num_lines, struct gpio_v2_line_config *config, unsigned int loops) { @@ -47,7 +48,7 @@ int monitor_device(const char *device_name, goto exit_free_name; } - ret = gpiotools_request_line(device_name, &line, 1, config, + ret = gpiotools_request_line(device_name, lines, num_lines, config, "gpio-event-mon"); if (ret < 0) goto exit_device_close; @@ -55,8 +56,10 @@ int monitor_device(const char *device_name, lfd = ret; /* Read initial states */ - values.mask = 1; + values.mask = 0; values.bits = 0; + for (i = 0; i < num_lines; i++) + gpiotools_set_bit(&values.mask, i); ret = gpiotools_get_values(lfd, &values); if (ret < 0) { fprintf(stderr, @@ -65,9 +68,23 @@ int monitor_device(const char *device_name, goto exit_line_close; } - fprintf(stdout, "Monitoring line %d on %s\n", line, device_name); - fprintf(stdout, "Initial line value: %d\n", - gpiotools_test_bit(values.bits, 0)); + if (num_lines == 1) { + fprintf(stdout, "Monitoring line %d on %s\n", lines[0], device_name); + fprintf(stdout, "Initial line value: %d\n", + gpiotools_test_bit(values.bits, 0)); + } else { + fprintf(stdout, "Monitoring lines %d", lines[0]); + for (i = 1; i < num_lines - 1; i++) + fprintf(stdout, ", %d", lines[i]); + fprintf(stdout, " and %d on %s\n", lines[i], device_name); + fprintf(stdout, "Initial line values: %d", + gpiotools_test_bit(values.bits, 0)); + for (i = 1; i < num_lines - 1; i++) + fprintf(stdout, ", %d", + gpiotools_test_bit(values.bits, i)); + fprintf(stdout, " and %d\n", + gpiotools_test_bit(values.bits, i)); + } while (1) { struct gpio_v2_line_event event; @@ -126,7 +143,7 @@ void print_usage(void) fprintf(stderr, "Usage: gpio-event-mon [options]...\n" "Listen to events on GPIO lines, 0->1 1->0\n" " -n Listen on GPIOs on a named device (must be stated)\n" - " -o Offset to monitor\n" + " -o Offset of line to monitor (may be repeated)\n" " -d Set line as open drain\n" " -s Set line as open source\n" " -r Listen for rising edges\n" @@ -146,7 +163,8 @@ void print_usage(void) int main(int argc, char **argv) { const char *device_name = NULL; - unsigned int line = -1; + unsigned int lines[GPIO_V2_LINES_MAX]; + unsigned int num_lines = 0; unsigned int loops = 0; struct gpio_v2_line_config config; int c; @@ -162,7 +180,12 @@ int main(int argc, char **argv) device_name = optarg; break; case 'o': - line = strtoul(optarg, NULL, 10); + if (num_lines >= GPIO_V2_LINES_MAX) { + print_usage(); + return -1; + } + lines[num_lines] = strtoul(optarg, NULL, 10); + num_lines++; break; case 'd': config.flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; @@ -182,7 +205,7 @@ int main(int argc, char **argv) } } - if (!device_name || line == -1) { + if (!device_name || num_lines == 0) { print_usage(); return -1; } @@ -191,5 +214,5 @@ int main(int argc, char **argv) "falling edges\n"); config.flags |= EDGE_FLAGS; } - return monitor_device(device_name, line, &config, loops); + return monitor_device(device_name, lines, num_lines, &config, loops); } From cf048e05b68789e9fa35f246f8ecbe95d79f4173 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Mon, 28 Sep 2020 08:28:07 +0800 Subject: [PATCH 32/32] tools: gpio: add debounce support to gpio-event-mon Add support for debouncing monitored lines to gpio-event-mon. Signed-off-by: Kent Gibson Reviewed-by: Andy Shevchenko Signed-off-by: Bartosz Golaszewski --- tools/gpio/gpio-event-mon.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/tools/gpio/gpio-event-mon.c b/tools/gpio/gpio-event-mon.c index 0c34f18f511c..90c3155f05b1 100644 --- a/tools/gpio/gpio-event-mon.c +++ b/tools/gpio/gpio-event-mon.c @@ -148,11 +148,12 @@ void print_usage(void) " -s Set line as open source\n" " -r Listen for rising edges\n" " -f Listen for falling edges\n" + " -b Debounce the line with period n microseconds\n" " [-c ] Do loops (optional, infinite loop if not stated)\n" " -? This helptext\n" "\n" "Example:\n" - "gpio-event-mon -n gpiochip0 -o 4 -r -f\n" + "gpio-event-mon -n gpiochip0 -o 4 -r -f -b 10000\n" ); } @@ -167,11 +168,12 @@ int main(int argc, char **argv) unsigned int num_lines = 0; unsigned int loops = 0; struct gpio_v2_line_config config; - int c; + int c, attr, i; + unsigned long debounce_period_us = 0; memset(&config, 0, sizeof(config)); config.flags = GPIO_V2_LINE_FLAG_INPUT; - while ((c = getopt(argc, argv, "c:n:o:dsrf?")) != -1) { + while ((c = getopt(argc, argv, "c:n:o:b:dsrf?")) != -1) { switch (c) { case 'c': loops = strtoul(optarg, NULL, 10); @@ -187,6 +189,9 @@ int main(int argc, char **argv) lines[num_lines] = strtoul(optarg, NULL, 10); num_lines++; break; + case 'b': + debounce_period_us = strtoul(optarg, NULL, 10); + break; case 'd': config.flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; break; @@ -205,6 +210,15 @@ int main(int argc, char **argv) } } + if (debounce_period_us) { + attr = config.num_attrs; + config.num_attrs++; + for (i = 0; i < num_lines; i++) + gpiotools_set_bit(&config.attrs[attr].mask, i); + config.attrs[attr].attr.id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE; + config.attrs[attr].attr.debounce_period_us = debounce_period_us; + } + if (!device_name || num_lines == 0) { print_usage(); return -1;