From 98ce1eb1fd87ea1b016e0913ef6836ab0139b5c4 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Thu, 20 Feb 2025 10:57:02 +0100 Subject: [PATCH] gpiolib: introduce gpio_chip setters that return values MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add new variants of the set() and set_multiple() callbacks that have integer return values allowing to indicate failures to users of the GPIO consumer API. Until we convert all GPIO providers treewide to using them, they will live in parallel to the existing ones. Make sure that providers cannot define both. Prefer the new ones and only use the old ones as fallback. Reviewed-by: Linus Walleij Acked-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20250220-gpio-set-retval-v2-5-bc4cfd38dae3@linaro.org Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 27 +++++++++++++++++++++++++-- include/linux/gpio/driver.h | 10 ++++++++++ 2 files changed, 35 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d26cad6442bf..1b4af0f97e5a 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -958,6 +958,11 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, int base = 0; int ret = 0; + /* Only allow one set() and one set_multiple(). */ + if ((gc->set && gc->set_rv) || + (gc->set_multiple && gc->set_multiple_rv)) + return -EINVAL; + /* * First: allocate and populate the internal stat container, and * set up the struct device. @@ -2827,11 +2832,21 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc) static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value) { + int ret; + lockdep_assert_held(&gc->gpiodev->srcu); - if (WARN_ON(unlikely(!gc->set))) + if (WARN_ON(unlikely(!gc->set && !gc->set_rv))) return -EOPNOTSUPP; + if (gc->set_rv) { + ret = gc->set_rv(gc, offset, value); + if (ret > 0) + ret = -EBADE; + + return ret; + } + gc->set(gc, offset, value); return 0; } @@ -3593,9 +3608,17 @@ static int gpiochip_set_multiple(struct gpio_chip *gc, lockdep_assert_held(&gc->gpiodev->srcu); - if (WARN_ON(unlikely(!gc->set_multiple && !gc->set))) + if (WARN_ON(unlikely(!gc->set_multiple && !gc->set_multiple_rv))) return -EOPNOTSUPP; + if (gc->set_multiple_rv) { + ret = gc->set_multiple_rv(gc, mask, bits); + if (ret > 0) + ret = -EBADE; + + return ret; + } + if (gc->set_multiple) { gc->set_multiple(gc, mask, bits); return 0; diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index ae96a2f260fb..a2a1b6434321 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -348,6 +348,10 @@ struct gpio_irq_chip { * stores them in "bits", returns 0 on success or negative error * @set: assigns output value for signal "offset" * @set_multiple: assigns output values for multiple signals defined by "mask" + * @set_rv: assigns output value for signal "offset", returns 0 on success or + * negative error value + * @set_multiple_rv: assigns output values for multiple signals defined by + * "mask", returns 0 on success or negative error value * @set_config: optional hook for all kinds of settings. Uses the same * packed config format as generic pinconf. Must return 0 on success and * a negative error number on failure. @@ -445,6 +449,12 @@ struct gpio_chip { void (*set_multiple)(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits); + int (*set_rv)(struct gpio_chip *gc, + unsigned int offset, + int value); + int (*set_multiple_rv)(struct gpio_chip *gc, + unsigned long *mask, + unsigned long *bits); int (*set_config)(struct gpio_chip *gc, unsigned int offset, unsigned long config); -- 2.50.1