diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 6d6e81242f74..c8a203fff4d1 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -8,12 +8,14 @@ * Copyright (C) 2007 MontaVista Software Inc. * Copyright (C) 2009 Provigent Ltd. */ +#include #include #include #include #include #include #include +#include #include #include #include @@ -130,6 +132,80 @@ static int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) return 0; } +#if defined(CONFIG_ACPI) && defined(CONFIG_GPIOLIB) +/* + * Check whether an ACPI GpioInt resource's referenced GPIO controller + * has finished probing. Resources with no named controller (resource + * source string) are skipped, since they can't be resolved to a + * struct device. + */ +static int check_gpioint_resource(struct acpi_resource *ares, void *data) +{ + struct acpi_resource_gpio *agpio; + struct acpi_device *gpio_adev; + struct device *gpio_dev; + acpi_handle handle; + acpi_status status; + + if (!acpi_gpio_get_irq_resource(ares, &agpio)) + return 1; /* not a GpioInt resource, skip */ + + if (!agpio->resource_source.string_length) + return 1; /* no named controller, skip */ + + status = acpi_get_handle(NULL, agpio->resource_source.string_ptr, &handle); + if (ACPI_FAILURE(status)) + return 1; + + gpio_adev = acpi_fetch_acpi_dev(handle); + if (!gpio_adev) + return 1; + + struct gpio_device *gdev __free(gpio_device_put) = + gpio_device_find_by_fwnode(acpi_fwnode_handle(gpio_adev)); + if (!gdev) + return -EPROBE_DEFER; /* controller not registered yet: abort walk */ + + gpio_dev = gpio_device_to_device(gdev)->parent; + + guard(device)(gpio_dev); + if (!device_is_bound(gpio_dev)) + return -EPROBE_DEFER; /* controller not bound yet: abort walk */ + + return 1; /* bound, skip adding to resource list, continue walk */ +} + +static int check_child_gpioint(struct acpi_device *adev, void *data) +{ + LIST_HEAD(res_list); + int ret; + + ret = acpi_dev_get_resources(adev, &res_list, check_gpioint_resource, NULL); + if (ret < 0) + return ret; + + acpi_dev_free_resource_list(&res_list); + + return 0; +} + +static int i2c_dw_check_gpio_dependencies(struct device *dev) +{ + struct acpi_device *adev; + + adev = ACPI_COMPANION(dev); + if (!adev) + return 0; + + return acpi_dev_for_each_child(adev, check_child_gpioint, NULL); +} +#else +static int i2c_dw_check_gpio_dependencies(struct device *dev) +{ + return 0; +} +#endif /* CONFIG_ACPI && CONFIG_GPIOLIB */ + static int dw_i2c_plat_probe(struct platform_device *pdev) { u32 flags = (uintptr_t)device_get_match_data(&pdev->dev); @@ -138,6 +214,10 @@ static int dw_i2c_plat_probe(struct platform_device *pdev) struct dw_i2c_dev *dev; int irq, ret; + ret = i2c_dw_check_gpio_dependencies(device); + if (ret) + return ret; + irq = platform_get_irq_optional(pdev, 0); if (irq == -ENXIO) flags |= ACCESS_POLLING;