[6/6] media: uvcvideo: Handle IRQs from the privacy_pin

If the privacy pin produces an IRQ, read the gpio and notify userspace
via an event.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c   |  3 +++
 drivers/media/usb/uvc/uvc_driver.c | 30 ++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

Hi


On Thu, Oct 22, 2020 at 3:38 PM Ricardo Ribalda <ribalda@chromium.org> wrote:
>
> If the privacy pin produces an IRQ, read the gpio and notify userspace
> via an event.
>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/uvc_ctrl.c   |  3 +++
>  drivers/media/usb/uvc/uvc_driver.c | 30 ++++++++++++++++++++++++++++++
>  2 files changed, 33 insertions(+)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 3a49a1326a90..00c41cba0f68 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1346,6 +1346,9 @@ static void uvc_ctrl_status_event_work(struct work_struct *work)
>
>         mutex_unlock(&chain->ctrl_mutex);
>
> +       if (!w->urb)
> +               return;
> +
>         /* Resubmit the URB. */
>         w->urb->interval = dev->int_ep->desc.bInterval;
>         ret = usb_submit_urb(w->urb, GFP_KERNEL);
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index 180e503e900f..d1260d131bd8 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1460,6 +1460,25 @@ static int uvc_gpio_get_info(struct uvc_entity *entity, u8 cs, u8 *caps)
>         return 0;
>  }
>
> +static irqreturn_t uvc_privacy_gpio_irq(int irq, void *data)
> +{
> +       struct uvc_device *dev = data;
> +       struct uvc_video_chain *chain;
> +       struct uvc_entity *term;
> +       u8 value;
> +
> +       list_for_each_entry(chain, &dev->chains, list) {
> +               list_for_each_entry(term, &dev->entities, list) {
> +                       if (UVC_ENTITY_TYPE(term) == UVC_GPIO_UNIT) {
> +                               value = gpiod_get_value(term->gpio.gpio_privacy);
> +                               uvc_ctrl_status_event(NULL, chain, term->controls, &value);
> +                       }
> +               }
> +       }
> +
> +       return IRQ_HANDLED;
> +}
> +
>  static int uvc_parse_gpio(struct uvc_device *dev)
>  {
>         struct uvc_entity *unit;
> @@ -1490,6 +1509,17 @@ static int uvc_parse_gpio(struct uvc_device *dev)
>
>         list_add_tail(&unit->list, &dev->entities);
>
> +       irq = gpiod_to_irq(gpio_privacy);
> +
> +       if (irq == -EPROBE_DEFER)
> +               return -EPROBE_DEFER;
> +
> +       if (irq < 0)
> +               return 0;
> +
> +       ret = devm_request_irq(&dev->udev->dev, irq, uvc_privacy_gpio_irq, IRQF_SHARED,
> +                              "uvc_privacy_gpio", dev);

Here it should say IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING instead
of IRQF_SHARED.

I will fix that on v2,

> +
>         return 0;
>  }
>
> --
> 2.29.0.rc1.297.gfa9743e501-goog
>

Hi Ricardo,

Thank you for the patch.

On Thu, Oct 22, 2020 at 03:37:53PM +0200, Ricardo Ribalda wrote:
> If the privacy pin produces an IRQ, read the gpio and notify userspace
> via an event.
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/uvc_ctrl.c   |  3 +++
>  drivers/media/usb/uvc/uvc_driver.c | 30 ++++++++++++++++++++++++++++++
>  2 files changed, 33 insertions(+)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 3a49a1326a90..00c41cba0f68 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1346,6 +1346,9 @@ static void uvc_ctrl_status_event_work(struct work_struct *work)
>  
>  	mutex_unlock(&chain->ctrl_mutex);
>  
> +	if (!w->urb)
> +		return;
> +
>  	/* Resubmit the URB. */
>  	w->urb->interval = dev->int_ep->desc.bInterval;
>  	ret = usb_submit_urb(w->urb, GFP_KERNEL);
> diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
> index 180e503e900f..d1260d131bd8 100644
> --- a/drivers/media/usb/uvc/uvc_driver.c
> +++ b/drivers/media/usb/uvc/uvc_driver.c
> @@ -1460,6 +1460,25 @@ static int uvc_gpio_get_info(struct uvc_entity *entity, u8 cs, u8 *caps)
>  	return 0;
>  }
>  
> +static irqreturn_t uvc_privacy_gpio_irq(int irq, void *data)
> +{
> +	struct uvc_device *dev = data;
> +	struct uvc_video_chain *chain;
> +	struct uvc_entity *term;

The entity isn't a terminal, so I'd call the variable unit. I think
there was another occurrence of this issue in another patch in the
series.

> +	u8 value;
> +
> +	list_for_each_entry(chain, &dev->chains, list) {

This will effectively call uvc_ctrl_status_event() once per chain, is
that really what you were intending ?

> +		list_for_each_entry(term, &dev->entities, list) {
> +			if (UVC_ENTITY_TYPE(term) == UVC_GPIO_UNIT) {
> +				value = gpiod_get_value(term->gpio.gpio_privacy);
> +				uvc_ctrl_status_event(NULL, chain, term->controls, &value);

80 columns.

> +			}
> +		}
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
>  static int uvc_parse_gpio(struct uvc_device *dev)
>  {
>  	struct uvc_entity *unit;
> @@ -1490,6 +1509,17 @@ static int uvc_parse_gpio(struct uvc_device *dev)
>  
>  	list_add_tail(&unit->list, &dev->entities);
>  
> +	irq = gpiod_to_irq(gpio_privacy);
> +

No need for a blank line.

And it looks like the local irq variable should be introduced in this
patch, not in the previous one. I think I'd squash this with 5/6.

> +	if (irq == -EPROBE_DEFER)
> +		return -EPROBE_DEFER;



> +
> +	if (irq < 0)
> +		return 0;
> +
> +	ret = devm_request_irq(&dev->udev->dev, irq, uvc_privacy_gpio_irq, IRQF_SHARED,

80 columns.

> +			       "uvc_privacy_gpio", dev);

Do we need to handle failures ?

> +
>  	return 0;
>  }
>