media: bcm2835-unicam: Add support for the FRAME_SYNC event

The FRAME_SYNC event is useful for userspace image processing algorithms
to program the camera sensor as early as possible after frame start.
Support it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>

diff --git a/drivers/media/platform/bcm2835/bcm2835-unicam.c b/drivers/media/platform/bcm2835/bcm2835-unicam.c
index 4840aa6..2ddac73 100644 (file)
--- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
+++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
@@ -772,6 +772,16 @@ static int unicam_all_nodes_disabled(struct unicam_device *dev)
               !dev->node[METADATA_PAD].streaming;
 }
 
+static void unicam_queue_event_sof(struct unicam_device *unicam)
+{
+       struct v4l2_event event = {
+               .type = V4L2_EVENT_FRAME_SYNC,
+               .u.frame_sync.frame_sequence = unicam->sequence,
+       };
+
+       v4l2_event_queue(&unicam->node[IMAGE_PAD].video_dev, &event);
+}
+
 /*
  * unicam_isr : ISR handler for unicam capture
  * @irq: irq number
@@ -853,6 +863,8 @@ static irqreturn_t unicam_isr(int irq, void *dev)
                         */
                        unicam_schedule_dummy_buffer(&unicam->node[i]);
                }
+
+               unicam_queue_event_sof(unicam);
        }
        /*
         * Cannot swap buffer at frame end, there may be a race condition
@@ -2022,6 +2034,8 @@ static int unicam_subscribe_event(struct v4l2_fh *fh,
                                  const struct v4l2_event_subscription *sub)
 {
        switch (sub->type) {
+       case V4L2_EVENT_FRAME_SYNC:
+               return v4l2_event_subscribe(fh, sub, 2, NULL);
        case V4L2_EVENT_SOURCE_CHANGE:
                return v4l2_event_subscribe(fh, sub, 4, NULL);
        }