Commit 3bc22dc6 authored by Ricardo Ribalda's avatar Ricardo Ribalda Committed by Laurent Pinchart
Browse files

media: uvcvideo: Only create input devs if hw supports it 



Examine the stream headers to figure out if the device has a button and
can be used as an input.

Signed-off-by: default avatarRicardo Ribalda <ribalda@chromium.org>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
parent 41ddb251

drivers/media/usb/uvc/uvc_status.c

+23 −0
Original line number Diff line number Diff line
@@ -18,11 +18,34 @@ 
 * Input device

 */

#ifdef CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV



static bool uvc_input_has_button(struct uvc_device *dev)

{

	struct uvc_streaming *stream;



	/*

	 * The device has button events if both bTriggerSupport and

	 * bTriggerUsage are one. Otherwise the camera button does not

	 * exist or is handled automatically by the camera without host

	 * driver or client application intervention.

	 */

	list_for_each_entry(stream, &dev->streams, list) {

		if (stream->header.bTriggerSupport == 1 &&

		    stream->header.bTriggerUsage == 1)

			return true;

	}



	return false;

}



static int uvc_input_init(struct uvc_device *dev)

{

	struct input_dev *input;

	int ret;



	if (!uvc_input_has_button(dev))

		return 0;



	input = input_allocate_device();

	if (input == NULL)

		return -ENOMEM;