This is a workaround for polarity unstable.
Sync value get by VR09C counts from sync's rising edge, which means
sync's polarity is negative if sync value is bigger than total/2.
Signed-off-by: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx>
---
drivers/media/platform/aspeed-video.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index 5ad3a20c5bac..f628f69bb7dd 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -989,6 +989,15 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
video->frame_top = FIELD_GET(VE_SRC_TB_EDGE_DET_TOP,
src_tb_edge);
det->vsync = FIELD_GET(VE_SYNC_STATUS_VSYNC, sync);
+ /*
+ * Workaround for polarity detection
+ * Use sync(VR098) counts from sync's rising edge till falling
+ * edge to tell sync polarity.
+ */
+ if (det->vsync > (FIELD_GET(VE_MODE_DETECT_V_LINES, mds) >> 1))
+ det->polarities &= ~V4L2_DV_VSYNC_POS_POL;
+ else
+ det->polarities |= V4L2_DV_VSYNC_POS_POL;
if (det->polarities & V4L2_DV_VSYNC_POS_POL) {
det->vbackporch = video->frame_top - det->vsync;
det->vfrontporch =
@@ -1010,6 +1019,15 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
video->frame_left = FIELD_GET(VE_SRC_LR_EDGE_DET_LEFT,
src_lr_edge);
det->hsync = FIELD_GET(VE_SYNC_STATUS_HSYNC, sync);
+ /*
+ * Workaround for polarity detection
+ * Use sync(VR098) counts from sync's rising edge till falling
+ * edge to tell sync polarity.
+ */
+ if (det->hsync > (htotal >> 1))
+ det->polarities &= ~V4L2_DV_HSYNC_POS_POL;
+ else
+ det->polarities |= V4L2_DV_HSYNC_POS_POL;
if (det->polarities & V4L2_DV_HSYNC_POS_POL) {
det->hbackporch = video->frame_left - det->hsync;
det->hfrontporch = htotal - video->frame_right;
--
2.25.1
