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

Hans Verkuil
2022-01-20T12:31:11Z

Hi Jammy,

I just want to double check this: I assume you have tested this with the
various polarity combinations?

I ask because I've never seen this before in any other hardware. The
sync and porch values reported by hardware are always independent from the
polarity, so that's why I am surprised to see this.

Same for the next patch (4/4).

Regards,

Hans

On 12/22/21 09:21, Jammy Huang wrote:
> 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;
>