| Message ID | 20240124101803.23580-1-brgl@bgdev.pl |
|---|---|
| State | New |
| Headers | show |
| Series | gpio: improve the API contract for setting direction | expand |
On Wed, Jan 24, 2024 at 11:18:03AM +0100, Bartosz Golaszewski wrote: > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > > 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 <joseguilhermebh@hotmail.com> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > --- > include/linux/gpio/driver.h | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h > index 9a5c6c76e653..c1c516b8a880 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, or returns a negative > + * error number. This can be omitted on input-only or output-only gpio > + * chips. > + * @direction_output: configures signal "offset" as output, or returns > + * 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 Also specify 0 on success, as per @get_multiple? It would be good to revise the documentation for all the ops, but this is a start. Cheers, Kent.
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 9a5c6c76e653..c1c516b8a880 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, or returns a negative + * error number. This can be omitted on input-only or output-only gpio + * chips. + * @direction_output: configures signal "offset" as output, or returns + * 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