[RFC v2 8/9] media: dwc: dw-hdmi-rx: Add support for Aspect Ratio

From: Nelson Costa
Date: Thu May 20 2021 - 11:48:27 EST


This adds support to get aspect ratio for the current
video being received and provide the info through v4l2
API query_dv_timings.

Signed-off-by: Nelson Costa <nelson.costa@xxxxxxxxxxxx>
---
drivers/media/platform/dwc/dw-hdmi-rx.c | 54 +++++++++++++++++++++++++++++++--
1 file changed, 52 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/dwc/dw-hdmi-rx.c b/drivers/media/platform/dwc/dw-hdmi-rx.c
index b20eccc..a468a93 100644
--- a/drivers/media/platform/dwc/dw-hdmi-rx.c
+++ b/drivers/media/platform/dwc/dw-hdmi-rx.c
@@ -2250,13 +2250,31 @@ static u32 dw_hdmi_get_width(struct dw_hdmi_dev *dw_dev)
return width;
}

+static int dw_hdmi_vic_to_cea861(u8 hdmi_vic)
+{
+ switch (hdmi_vic) {
+ case 1:
+ return 95;
+ case 2:
+ return 94;
+ case 3:
+ return 93;
+ case 4:
+ return 98;
+ default:
+ return 0;
+ }
+}
+
static int dw_hdmi_query_dv_timings(struct v4l2_subdev *sd,
struct v4l2_dv_timings *timings)
{
struct dw_hdmi_dev *dw_dev = to_dw_dev(sd);
struct v4l2_bt_timings *bt = &timings->bt;
+ struct v4l2_dv_timings t = {0};
bool is_hdmi_vic;
u32 htot, hofs;
+ u8 cea861_vic;
u32 vtot;
u8 vic;

@@ -2351,8 +2369,40 @@ static int dw_hdmi_query_dv_timings(struct v4l2_subdev *sd,
}
}

- dev_dbg(dw_dev->dev, "%s: width=%u, height=%u, mbuscode=%u\n", __func__,
- bt->width, bt->height, dw_hdmi_get_mbus_code(dw_dev));
+ if (is_hdmi_vic)
+ cea861_vic = dw_hdmi_vic_to_cea861(bt->hdmi_vic);
+ else
+ cea861_vic = vic;
+
+ /* picture aspect ratio based on v4l2 dv timings array */
+ if (v4l2_find_dv_timings_cea861_vic(&t, cea861_vic)) {
+ /* when the numerator/denominator are zero means that the
+ * picture aspect ratio is the same of the active measures ratio
+ */
+ if (!t.bt.picture_aspect.numerator) {
+ unsigned long n, d;
+
+ rational_best_approximation(t.bt.width, t.bt.height,
+ t.bt.width, t.bt.height,
+ &n, &d);
+ t.bt.picture_aspect.numerator = n;
+ t.bt.picture_aspect.denominator = d;
+ }
+
+ bt->picture_aspect = t.bt.picture_aspect;
+ } else {
+ bt->picture_aspect.numerator = 0;
+ bt->picture_aspect.denominator = 0;
+ dev_dbg(dw_dev->dev,
+ "%s: cea861_vic=%d was not found in v4l2 dv timings",
+ __func__, cea861_vic);
+ }
+
+ dev_dbg(dw_dev->dev,
+ "%s: width=%u, height=%u, mbuscode=%u, cea861_vic=%d, ar={%d,%d}\n",
+ __func__, bt->width, bt->height, dw_hdmi_get_mbus_code(dw_dev),
+ cea861_vic, bt->picture_aspect.numerator,
+ bt->picture_aspect.denominator);

return 0;
}
--
2.7.4