media: mediatek: vcodec: Report supported bitrate modes

The media driver supports constant bitrate mode only.
The supported rate control mode is reported through querymenu() and
s_ctrl() fails if non constant bitrate mode (e.g. VBR) is requested.
Signed-off-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Irui Wang <irui.wang@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c

@@ -50,6 +50,14 @@ static int vidioc_venc_s_ctrl(struct v4l2_ctrl *ctrl)
 	int ret = 0;
 
 	switch (ctrl->id) {
+	case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:
+		mtk_v4l2_debug(2, "V4L2_CID_MPEG_VIDEO_BITRATE_MODE val= %d",
+			       ctrl->val);
+		if (ctrl->val != V4L2_MPEG_VIDEO_BITRATE_MODE_CBR) {
+			mtk_v4l2_err("Unsupported bitrate mode =%d", ctrl->val);
+			ret = -EINVAL;
+		}
+		break;
 	case V4L2_CID_MPEG_VIDEO_BITRATE:
 		mtk_v4l2_debug(2, "V4L2_CID_MPEG_VIDEO_BITRATE val = %d",
 			       ctrl->val);
@@ -1392,6 +1400,9 @@ int mtk_vcodec_enc_ctrls_setup(struct mtk_vcodec_ctx *ctx)
 			       0, V4L2_MPEG_VIDEO_H264_LEVEL_4_0);
 	v4l2_ctrl_new_std_menu(handler, ops, V4L2_CID_MPEG_VIDEO_VP8_PROFILE,
 			       V4L2_MPEG_VIDEO_VP8_PROFILE_0, 0, V4L2_MPEG_VIDEO_VP8_PROFILE_0);
+	v4l2_ctrl_new_std_menu(handler, ops, V4L2_CID_MPEG_VIDEO_BITRATE_MODE,
+			       V4L2_MPEG_VIDEO_BITRATE_MODE_CBR,
+			       0, V4L2_MPEG_VIDEO_BITRATE_MODE_CBR);
 
 
 	if (handler->error) {