[PATCH 1/3] i2c: adv748x: store number of CSI-2 lanes described in device tree

[Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>]

The adv748x CSI-2 transmitters TXA and TXB can use different number of
lines to transmit data on. In order to be able configure the device
correctly this information need to be parsed from device tree and stored
in each TX private data structure.

TXA supports 1, 2 and 4 lanes while TXB supports 1 lane.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
---
 drivers/media/i2c/adv748x/adv748x-core.c | 49 ++++++++++++++++++++++++
 drivers/media/i2c/adv748x/adv748x.h      |  1 +
 2 files changed, 50 insertions(+)

diff --git a/drivers/media/i2c/adv748x/adv748x-core.c b/drivers/media/i2c/adv748x/adv748x-core.c
index 85c027bdcd56748d..a93f8ea89a228474 100644
--- a/drivers/media/i2c/adv748x/adv748x-core.c
+++ b/drivers/media/i2c/adv748x/adv748x-core.c
@@ -23,6 +23,7 @@
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-dv-timings.h>
+#include <media/v4l2-fwnode.h>
 #include <media/v4l2-ioctl.h>
 
 #include "adv748x.h"
@@ -561,11 +562,54 @@ void adv748x_subdev_init(struct v4l2_subdev *sd, struct adv748x_state *state,
 	sd->entity.ops = &adv748x_media_ops;
 }
 
+static int adv748x_parse_csi2_lanes(struct adv748x_state *state,
+				    unsigned int port,
+				    struct device_node *ep)
+{
+	struct v4l2_fwnode_endpoint vep;
+	unsigned int num_lanes;
+	int ret;
+
+	if (port != ADV748X_PORT_TXA && port != ADV748X_PORT_TXB)
+		return 0;
+
+	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &vep);
+	if (ret)
+		return ret;
+
+	num_lanes = vep.bus.mipi_csi2.num_data_lanes;
+
+	if (vep.base.port == ADV748X_PORT_TXA) {
+		if (num_lanes != 1 && num_lanes != 2 && num_lanes != 4) {
+			adv_err(state, "TXA: Invalid number (%d) of lanes\n",
+				num_lanes);
+			return -EINVAL;
+		}
+
+		state->txa.num_lanes = num_lanes;
+		adv_dbg(state, "TXA: using %d lanes\n", state->txa.num_lanes);
+	}
+
+	if (vep.base.port == ADV748X_PORT_TXB) {
+		if (num_lanes != 1) {
+			adv_err(state, "TXB: Invalid number (%d) of lanes\n",
+				num_lanes);
+			return -EINVAL;
+		}
+
+		state->txb.num_lanes = num_lanes;
+		adv_dbg(state, "TXB: using %d lanes\n", state->txb.num_lanes);
+	}
+
+	return 0;
+}
+
 static int adv748x_parse_dt(struct adv748x_state *state)
 {
 	struct device_node *ep_np = NULL;
 	struct of_endpoint ep;
 	bool found = false;
+	int ret;
 
 	for_each_endpoint_of_node(state->dev->of_node, ep_np) {
 		of_graph_parse_endpoint(ep_np, &ep);
@@ -589,6 +633,11 @@ static int adv748x_parse_dt(struct adv748x_state *state)
 		state->endpoints[ep.port] = ep_np;
 
 		found = true;
+
+		/* Store number of CSI-2 lanes used for TXA and TXB. */
+		ret = adv748x_parse_csi2_lanes(state, ep.port, ep_np);
+		if (ret)
+			return ret;
 	}
 
 	return found ? 0 : -ENODEV;
diff --git a/drivers/media/i2c/adv748x/adv748x.h b/drivers/media/i2c/adv748x/adv748x.h
index c9016acaba34aff2..88ad06a3045c5427 100644
--- a/drivers/media/i2c/adv748x/adv748x.h
+++ b/drivers/media/i2c/adv748x/adv748x.h
@@ -78,6 +78,7 @@ struct adv748x_csi2 {
 	struct adv748x_state *state;
 	struct v4l2_mbus_framefmt format;
 	unsigned int page;
+	unsigned int num_lanes;
 
 	struct media_pad pads[ADV748X_CSI2_NR_PADS];
 	struct v4l2_ctrl_handler ctrl_hdl;
-- 
2.18.0