[PATCH v2 3/4] media: aspeed: Correct values for detected timing

Jammy Huang
2021-12-22T08:22:15Z

Correct timing's fp/sync/bp value based on the information below.
It should be noticed that the calculation formula should be changed
per sync polarity.

The sequence of signal: sync - backporch - video data - frontporch

The following registers start counting from sync's rising edge:
1. VR090: frame edge's left and right
2. VR094: frame edge's top and bottom
3. VR09C: counting from sync's rising edge to falling edge

[Vertical timing]
+--+ +-------------------+ +--+
| | | v i d e o | | |
+--+ +-----+ +-----+ +---+

vsync+--+
frame_top+--------+
frame_bottom+----------------------------+

+-------------------+
| v i d e o |
+--+ +-----+ +-----+ +---+
| | | |
+--+ +--+
vsync+-------------------------------+
frame_top+-----+
frame_bottom+-------------------------+

[Horizontal timing]
+--+ +-------------------+ +--+
| | | v i d e o | | |
+--+ +-----+ +-----+ +---+

hsync+--+
frame_left+--------+
frame_right+----------------------------+

+-------------------+
| v i d e o |
+--+ +-----+ +-----+ +---+
| | | |
+--+ +--+
hsync+-------------------------------+
frame_left+-----+
frame_right+-------------------------+

Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com>
---
v2:
- Code refined per Joel's suggestion
- Update commit message to have name matching variable
---
drivers/media/platform/aspeed-video.c | 30 ++++++++++++++++++++-------
1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c
index c241038ee27c..7c50567f5ab0 100644
--- a/drivers/media/platform/aspeed-video.c
+++ b/drivers/media/platform/aspeed-video.c
@@ -936,7 +936,7 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
u32 src_lr_edge;
u32 src_tb_edge;
u32 sync;
- u32 htotal;
+ u32 htotal, vtotal, vsync, hsync;
struct v4l2_bt_timings *det = &video->detected_timings;

det->width = MIN_WIDTH;
@@ -983,21 +983,35 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
mds = aspeed_video_read(video, VE_MODE_DETECT_STATUS);
sync = aspeed_video_read(video, VE_SYNC_STATUS);
htotal = aspeed_video_read(video, VE_H_TOTAL_PIXELS);
+ vtotal = FIELD_GET(VE_MODE_DETECT_V_LINES, mds);
+ vsync = FIELD_GET(VE_SYNC_STATUS_VSYNC, sync);
+ hsync = FIELD_GET(VE_SYNC_STATUS_HSYNC, sync);

video->frame_bottom = FIELD_GET(VE_SRC_TB_EDGE_DET_BOT, src_tb_edge);
video->frame_top = FIELD_GET(VE_SRC_TB_EDGE_DET_TOP, src_tb_edge);
- det->vfrontporch = video->frame_top;
- det->vbackporch = FIELD_GET(VE_MODE_DETECT_V_LINES, mds) -
- video->frame_bottom;
- det->vsync = FIELD_GET(VE_SYNC_STATUS_VSYNC, sync);
+ if (det->polarities & V4L2_DV_VSYNC_POS_POL) {
+ det->vbackporch = video->frame_top - vsync;
+ det->vfrontporch = vtotal - video->frame_bottom;
+ det->vsync = vsync;
+ } else {
+ det->vbackporch = video->frame_top;
+ det->vfrontporch = vsync - video->frame_bottom;
+ det->vsync = vtotal - vsync;
+ }
if (video->frame_top > video->frame_bottom)
continue;

video->frame_right = FIELD_GET(VE_SRC_LR_EDGE_DET_RT, src_lr_edge);
video->frame_left = FIELD_GET(VE_SRC_LR_EDGE_DET_LEFT, src_lr_edge);
- det->hfrontporch = video->frame_left;
- det->hbackporch = htotal - video->frame_right;
- det->hsync = FIELD_GET(VE_SYNC_STATUS_HSYNC, sync);
+ if (det->polarities & V4L2_DV_HSYNC_POS_POL) {
+ det->hbackporch = video->frame_left - hsync;
+ det->hfrontporch = htotal - video->frame_right;
+ det->hsync = hsync;
+ } else {
+ det->hbackporch = video->frame_left;
+ det->hfrontporch = hsync - video->frame_right;
+ det->hsync = htotal - hsync;
+ }
if (video->frame_left > video->frame_right)
continue;

--
2.25.1