From c18790018799155e58d5a11c6697f9c398bf8b60 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 9 Jan 2026 14:08:32 +0100 Subject: [PATCH 1/2] gpio: davinci: implement .get_direction() It's strongly recommended for GPIO drivers to always implement the .get_direction() callback - even for fixed-direction controllers. GPIO core will even emit a warning if the callback is missing, when users try to read the direction of a pin. Implement .get_direction() for gpio-davinci. Reported-by: Michael Walle Closes: https://lore.kernel.org/all/DFJAFK3DTBOZ.3G2P3A5IH34GF@kernel.org/ Reviewed-by: Linus Walleij Fixes: a060b8c511ab ("gpiolib: implement low-level, shared GPIO support") Tested-by: Michael Walle # on sa67 Link: https://lore.kernel.org/r/20260109130832.27326-1-bartosz.golaszewski@oss.qualcomm.com Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-davinci.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c index 538f27209ce7..97780f27ce5b 100644 --- a/drivers/gpio/gpio-davinci.c +++ b/drivers/gpio/gpio-davinci.c @@ -6,6 +6,7 @@ * Copyright (c) 2007, MontaVista Software, Inc. */ +#include #include #include #include @@ -109,6 +110,22 @@ davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value) return __davinci_direction(chip, offset, true, value); } +static int davinci_get_direction(struct gpio_chip *chip, unsigned int offset) +{ + struct davinci_gpio_controller *d = gpiochip_get_data(chip); + struct davinci_gpio_regs __iomem *g; + u32 mask = __gpio_mask(offset), val; + int bank = offset / 32; + + g = d->regs[bank]; + + guard(spinlock_irqsave)(&d->lock); + + val = readl_relaxed(&g->dir); + + return (val & mask) ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; +} + /* * Read the pin's value (works even if it's set up as output); * returns zero/nonzero. @@ -203,6 +220,7 @@ static int davinci_gpio_probe(struct platform_device *pdev) chips->chip.get = davinci_gpio_get; chips->chip.direction_output = davinci_direction_out; chips->chip.set = davinci_gpio_set; + chips->chip.get_direction = davinci_get_direction; chips->chip.ngpio = ngpio; chips->chip.base = -1; From 471e998c0e31206ff0eac7202b2659698cf9b46e Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 9 Jan 2026 11:55:56 +0100 Subject: [PATCH 2/2] gpiolib: remove redundant callback check The presence of the .get_direction() callback is already checked in gpiochip_get_direction(). Remove the duplicated check which also returns the wrong error code to user-space. Fixes: e623c4303ed1 ("gpiolib: sanitize the return value of gpio_chip::get_direction()") Reported-by: Michael Walle Closes: https://lore.kernel.org/all/DFJAFK3DTBOZ.3G2P3A5IH34GF@kernel.org/ Link: https://lore.kernel.org/r/20260109105557.20024-1-bartosz.golaszewski@oss.qualcomm.com Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index dcf427d3cf43..fe2d107b0a84 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -468,9 +468,6 @@ int gpiod_get_direction(struct gpio_desc *desc) test_bit(GPIOD_FLAG_IS_OUT, &flags)) return 0; - if (!guard.gc->get_direction) - return -ENOTSUPP; - ret = gpiochip_get_direction(guard.gc, offset); if (ret < 0) return ret;