media: ov5647: Add support for non-continuous clock mode

Add support for optional non-continuous clock mode to the ov5647
sensor driver.

Non-continuous clock saves a small amount of power and on some SoCs
is easier to interface with.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/i2c/ov5647.c

@@ -44,6 +44,7 @@
 #define PWDN_ACTIVE_DELAY_MS	20
 
 #define MIPI_CTRL00_CLOCK_LANE_GATE		BIT(5)
+#define MIPI_CTRL00_LINE_SYNC_ENABLE		BIT(4)
 #define MIPI_CTRL00_BUS_IDLE			BIT(2)
 #define MIPI_CTRL00_CLOCK_LANE_DISABLE		BIT(0)
 
@@ -95,6 +96,7 @@ struct ov5647 {
 	int				power_count;
 	struct clk			*xclk;
 	struct gpio_desc		*pwdn;
+	bool				clock_ncont;
 };
 
 static inline struct ov5647 *to_state(struct v4l2_subdev *sd)
@@ -269,9 +271,15 @@ static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
 
 static int ov5647_stream_on(struct v4l2_subdev *sd)
 {
+	struct ov5647 *ov5647 = to_state(sd);
+	u8 val = MIPI_CTRL00_BUS_IDLE;
 	int ret;
 
-	ret = ov5647_write(sd, OV5647_REG_MIPI_CTRL00, MIPI_CTRL00_BUS_IDLE);
+	if (ov5647->clock_ncont)
+		val |= MIPI_CTRL00_CLOCK_LANE_GATE |
+		       MIPI_CTRL00_LINE_SYNC_ENABLE;
+
+	ret = ov5647_write(sd, OV5647_REG_MIPI_CTRL00, val);
 	if (ret < 0)
 		return ret;
 
@@ -546,9 +554,11 @@ static const struct v4l2_subdev_internal_ops ov5647_subdev_internal_ops = {
 	.open = ov5647_open,
 };
 
-static int ov5647_parse_dt(struct device_node *np)
+static int ov5647_parse_dt(struct ov5647 *sensor, struct device_node *np)
 {
-	struct v4l2_fwnode_endpoint bus_cfg = { .bus_type = 0 };
+	struct v4l2_fwnode_endpoint bus_cfg = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY,
+	};
 	struct device_node *ep;
 
 	int ret;
@@ -558,7 +568,13 @@ static int ov5647_parse_dt(struct device_node *np)
 		return -EINVAL;
 
 	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &bus_cfg);
+	if (ret)
+		goto out;
 
+	sensor->clock_ncont = bus_cfg.bus.mipi_csi2.flags &
+			      V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
+
+out:
 	of_node_put(ep);
 	return ret;
 }
@@ -577,7 +593,7 @@ static int ov5647_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	if (IS_ENABLED(CONFIG_OF) && np) {
-		ret = ov5647_parse_dt(np);
+		ret = ov5647_parse_dt(sensor, np);
 		if (ret) {
 			dev_err(dev, "DT parsing error: %d\n", ret);
 			return ret;