media: ti: cal: use frame desc to get vc and dt

Use get_frame_desc() to get the frame desc from the connected source,
and use the provided virtual channel and datatype instead of hardcoded
ones.

get_frame_desc() can contain multiple streams, but as we don't support
multiple streams yet, we will just always use the first stream.

If the source doesn't support get_frame_desc(), fall back to the
previous method of always capturing virtual channel 0 and any datatype.

Signed-off-by: Tomi Valkeinen <[e-mail]>
Reviewed-by: Jacopo Mondi <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/ti/cal/cal-camerarx.c

···
 	return ret;
 }
 
+int cal_camerarx_get_remote_frame_desc(struct cal_camerarx *phy,
+				       struct v4l2_mbus_frame_desc *desc)
+{
+	struct media_pad *pad;
+	int ret;
+
+	if (!phy->source)
+		return -EPIPE;
+
+	pad = media_entity_remote_pad(&phy->pads[CAL_CAMERARX_PAD_SINK]);
+	if (!pad)
+		return -EPIPE;
+
+	ret = v4l2_subdev_call(phy->source, pad, get_frame_desc, pad->index,
+			       desc);
+	if (ret)
+		return ret;
+
+	if (desc->type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
+		dev_err(phy->cal->dev,
+			"Frame descriptor does not describe CSI-2 link");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /* ------------------------------------------------------------------
  *	V4L2 Subdev Operations
  * ------------------------------------------------------------------

drivers/media/platform/ti/cal/cal.c

···
 	return stopped;
 }
 
+static int
+cal_get_remote_frame_desc_entry(struct cal_camerarx *phy,
+				struct v4l2_mbus_frame_desc_entry *entry)
+{
+	struct v4l2_mbus_frame_desc fd;
+	int ret;
+
+	ret = cal_camerarx_get_remote_frame_desc(phy, &fd);
+	if (ret) {
+		if (ret != -ENOIOCTLCMD)
+			dev_err(phy->cal->dev,
+				"Failed to get remote frame desc: %d\n", ret);
+		return ret;
+	}
+
+	if (fd.num_entries == 0) {
+		dev_err(phy->cal->dev,
+			"No streams found in the remote frame descriptor\n");
+
+		return -ENODEV;
+	}
+
+	if (fd.num_entries > 1)
+		dev_dbg(phy->cal->dev,
+			"Multiple streams not supported in remote frame descriptor, using the first one\n");
+
+	*entry = fd.entry[0];
+
+	return 0;
+}
+
 int cal_ctx_prepare(struct cal_ctx *ctx)
 {
+	struct v4l2_mbus_frame_desc_entry entry;
 	int ret;
+
+	ret = cal_get_remote_frame_desc_entry(ctx->phy, &entry);
+
+	if (ret == -ENOIOCTLCMD) {
+		ctx->vc = 0;
+		ctx->datatype = CAL_CSI2_CTX_DT_ANY;
+	} else if (!ret) {
+		ctx_dbg(2, ctx, "Framedesc: len %u, vc %u, dt %#x\n",
+			entry.length, entry.bus.csi2.vc, entry.bus.csi2.dt);
+
+		ctx->vc = entry.bus.csi2.vc;
+		ctx->datatype = entry.bus.csi2.dt;
+	} else {
+		return ret;
+	}
 
 	ctx->use_pix_proc = !ctx->fmtinfo->meta;
 
···
 	ctx->dma_ctx = inst;
 	ctx->csi2_ctx = inst;
 	ctx->cport = inst;
-	ctx->vc = 0;
-	ctx->datatype = CAL_CSI2_CTX_DT_ANY;
 
 	ret = cal_ctx_v4l2_init(ctx);
 	if (ret)

drivers/media/platform/ti/cal/cal.h

···
 
 void cal_quickdump_regs(struct cal_dev *cal);
 
+int cal_camerarx_get_remote_frame_desc(struct cal_camerarx *phy,
+				       struct v4l2_mbus_frame_desc *desc);
 void cal_camerarx_disable(struct cal_camerarx *phy);
 void cal_camerarx_i913_errata(struct cal_camerarx *phy);
 struct cal_camerarx *cal_camerarx_create(struct cal_dev *cal,