Re: [PATCH v4 2/5] gpiolib: add support for pull up/down to lineevent_create

[Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>]

pon., 28 paź 2019 o 08:38 Kent Gibson <warthog618@xxxxxxxxx> napisał(a):
>
> Add support for pull up/down to lineevent_create.
> Use cases include receiving asynchronous presses from a
> push button without an external pull up/down.
>
> Also restrict the application of bias to lines
> explicitly requested as inputs to prevent bias being applied
> to as-is line requests.
>
> Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx>
> ---
>  drivers/gpio/gpiolib.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index e80e689be2cc..7dfbb3676ee0 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -554,6 +554,12 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
>              (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
>                 return -EINVAL;
>
> +       /* PULL_UP and PULL_DOWN flags only make sense for input mode. */
> +       if (!(lflags & GPIOHANDLE_REQUEST_INPUT) &&
> +           ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
> +            (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
> +               return -EINVAL;
> +

This is not part of this patch - this must go into 1/5.

Bart

>         lh = kzalloc(sizeof(*lh), GFP_KERNEL);
>         if (!lh)
>                 return -ENOMEM;
> @@ -944,6 +950,10 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
>
>         if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW)
>                 set_bit(FLAG_ACTIVE_LOW, &desc->flags);
> +       if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)
> +               set_bit(FLAG_PULL_DOWN, &desc->flags);
> +       if (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)
> +               set_bit(FLAG_PULL_UP, &desc->flags);
>

Bart.


>         ret = gpiod_direction_input(desc);
>         if (ret)
> --
> 2.23.0
>