Re: [PATCH v2 2/6] gpiolib: add support for pull up/down to lineevent_create

[Bartosz Golaszewski <brgl@xxxxxxxx>]

sob., 12 paź 2019 o 03:57 Kent Gibson <warthog618@xxxxxxxxx> napisał(a):
>
> This patch adds support for pull up/down to lineevent_create.
> Use cases include receiving asynchronous presses from a
> push button without an external pull up/down.
>
> Move all the flags sanitization before any memory allocation in
> lineevent_create() in order to remove a couple unneeded gotos.
> (from Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>)
>

The patch you pulled in into your commit already sits in my for-next branch.
I didn't know you would be modifying the code I touched earlier. In this case
you can rebase the series on top of gpio/for-next from my tree[1]

> Signed-off-by: Kent Gibson <warthog618@xxxxxxxxx>
> ---
>  drivers/gpio/gpiolib.c | 60 +++++++++++++++++++++++++-----------------
>  1 file changed, 36 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 9d2a5e2f6e77..053847b6187f 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -905,6 +905,38 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
>         if (copy_from_user(&eventreq, ip, sizeof(eventreq)))
>                 return -EFAULT;
>
> +       offset = eventreq.lineoffset;
> +       lflags = eventreq.handleflags;
> +       eflags = eventreq.eventflags;
> +
> +       if (offset >= gdev->ngpio)
> +               return -EINVAL;
> +
> +       /* Return an error if a unknown flag is set */
> +       if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
> +           (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS))
> +               return -EINVAL;
> +
> +       /* This is just wrong: we don't look for events on output lines */
> +       if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
> +           (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
> +           (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_PULL_UP) ||
> +            (lflags & GPIOHANDLE_REQUEST_PULL_DOWN)))
> +               return -EINVAL;
> +
> +       /*
> +        * Do not allow both pull-up and pull-down flags to be set as they
> +        *  are contradictory.
> +        */
> +       if ((lflags & GPIOHANDLE_REQUEST_PULL_UP) &&
> +           (lflags & GPIOHANDLE_REQUEST_PULL_DOWN))
> +               return -EINVAL;
> +
>         le = kzalloc(sizeof(*le), GFP_KERNEL);
>         if (!le)
>                 return -ENOMEM;
> @@ -922,30 +954,6 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
>                 }
>         }
>
> -       offset = eventreq.lineoffset;
> -       lflags = eventreq.handleflags;
> -       eflags = eventreq.eventflags;
> -
> -       if (offset >= gdev->ngpio) {
> -               ret = -EINVAL;
> -               goto out_free_label;
> -       }
> -
> -       /* Return an error if a unknown flag is set */
> -       if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) ||
> -           (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) {
> -               ret = -EINVAL;
> -               goto out_free_label;
> -       }
> -
> -       /* This is just wrong: we don't look for events on output lines */
> -       if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) ||
> -           (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
> -           (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) {
> -               ret = -EINVAL;
> -               goto out_free_label;
> -       }
> -
>         desc = &gdev->descs[offset];
>         ret = gpiod_request(desc, le->label);
>         if (ret)
> @@ -955,6 +963,10 @@ 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_PULL_DOWN)
> +               set_bit(FLAG_PULL_DOWN, &desc->flags);
> +       if (lflags & GPIOHANDLE_REQUEST_PULL_UP)
> +               set_bit(FLAG_PULL_UP, &desc->flags);
>

Correct me if I'm wrong but this looks like it should be part of
Drew's patch (1/6) in this series right? You can modify it and add
your Signed-off-by tag. In fact your Signed-off-by is needed anyway if
you're sending someone else's patches.

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

Bart

[1] https://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git/