From: Bartosz Golaszewski Date: Thu, 25 Jan 2024 08:35:07 +0000 (+0100) Subject: gpio: improve the API contract for setting direction X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6933ba529d06afdd3faf5501855e410b46b77160;p=linux.git gpio: improve the API contract for setting direction If a GPIO driver returns a positive integer from one of the direction setter callbacks, we'll end up propagating it to user-space. Whether we should sanitize the values returned by callbacks is a different question but let's first improve the documentation and fortify the contract with GPIO providers. Reported-by: José Guilherme de Castro Rodrigues Signed-off-by: Bartosz Golaszewski Reviewed-by: Kent Gibson --- diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 363d06c7b637c..3a37d058cfcfe 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -335,10 +335,12 @@ struct gpio_irq_chip { * (same as GPIO_LINE_DIRECTION_OUT / GPIO_LINE_DIRECTION_IN), * or negative error. It is recommended to always implement this * function, even on input-only or output-only gpio chips. - * @direction_input: configures signal "offset" as input, or returns error - * This can be omitted on input-only or output-only gpio chips. - * @direction_output: configures signal "offset" as output, or returns error - * This can be omitted on input-only or output-only gpio chips. + * @direction_input: configures signal "offset" as input, returns 0 on success + * or a negative error number. This can be omitted on input-only or + * output-only gpio chips. + * @direction_output: configures signal "offset" as output, returns 0 on + * success or a negative error number. This can be omitted on input-only + * or output-only gpio chips. * @get: returns value for signal "offset", 0=low, 1=high, or negative error * @get_multiple: reads values for multiple signals defined by "mask" and * stores them in "bits", returns 0 on success or negative error