[PATCH 1/5] media: i2c: imx290: Add support for 2 data lanes

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

The IMX290 sensor can output frames with 2/4 CSI2 data lanes. This commit
adds support for 2 lane mode in addition to the 4 lane and also
configuring the data lane settings in the driver based on system
configuration.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/media/i2c/imx290.c | 130 ++++++++++++++++++++++++++++++++++---
 1 file changed, 121 insertions(+), 9 deletions(-)

diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
index f7678e5a5d87..1d49910937fb 100644
--- a/drivers/media/i2c/imx290.c
+++ b/drivers/media/i2c/imx290.c
@@ -25,7 +25,18 @@
 #define IMX290_STANDBY 0x3000
 #define IMX290_REGHOLD 0x3001
 #define IMX290_XMSTA 0x3002
+#define IMX290_FR_FDG_SEL 0x3009
 #define IMX290_GAIN 0x3014
+#define IMX290_HMAX_LOW 0x301c
+#define IMX290_HMAX_HIGH 0x301d
+#define IMX290_PHY_LANE_NUM 0x3407
+#define IMX290_CSI_LANE_MODE 0x3443
+
+/* HMAX fields */
+#define IMX290_HMAX_2_1920 0x1130
+#define IMX290_HMAX_4_1920 0x0898
+#define IMX290_HMAX_2_720 0x19C8
+#define IMX290_HMAX_4_720 0x0CE4
 
 #define IMX290_DEFAULT_LINK_FREQ 445500000
 
@@ -56,6 +67,7 @@ struct imx290 {
 	struct device *dev;
 	struct clk *xclk;
 	struct regmap *regmap;
+	int nlanes;
 
 	struct v4l2_subdev sd;
 	struct v4l2_fwnode_endpoint ep;
@@ -89,14 +101,11 @@ static const struct regmap_config imx290_regmap_config = {
 
 static const struct imx290_regval imx290_global_init_settings[] = {
 	{ 0x3007, 0x00 },
-	{ 0x3009, 0x00 },
 	{ 0x3018, 0x65 },
 	{ 0x3019, 0x04 },
 	{ 0x301a, 0x00 },
-	{ 0x3443, 0x03 },
 	{ 0x3444, 0x20 },
 	{ 0x3445, 0x25 },
-	{ 0x3407, 0x03 },
 	{ 0x303a, 0x0c },
 	{ 0x3040, 0x00 },
 	{ 0x3041, 0x00 },
@@ -169,7 +178,6 @@ static const struct imx290_regval imx290_1080p_settings[] = {
 	{ 0x3164, 0x1a },
 	{ 0x3480, 0x49 },
 	/* data rate settings */
-	{ 0x3009, 0x01 },
 	{ 0x3405, 0x10 },
 	{ 0x3446, 0x57 },
 	{ 0x3447, 0x00 },
@@ -187,8 +195,6 @@ static const struct imx290_regval imx290_1080p_settings[] = {
 	{ 0x3453, 0x00 },
 	{ 0x3454, 0x17 },
 	{ 0x3455, 0x00 },
-	{ 0x301c, 0x98 },
-	{ 0x301d, 0x08 },
 };
 
 static const struct imx290_regval imx290_720p_settings[] = {
@@ -210,7 +216,6 @@ static const struct imx290_regval imx290_720p_settings[] = {
 	{ 0x3164, 0x1a },
 	{ 0x3480, 0x49 },
 	/* data rate settings */
-	{ 0x3009, 0x01 },
 	{ 0x3405, 0x10 },
 	{ 0x3446, 0x4f },
 	{ 0x3447, 0x00 },
@@ -228,8 +233,6 @@ static const struct imx290_regval imx290_720p_settings[] = {
 	{ 0x3453, 0x00 },
 	{ 0x3454, 0x17 },
 	{ 0x3455, 0x00 },
-	{ 0x301c, 0xe4 },
-	{ 0x301d, 0x0c },
 };
 
 static const struct imx290_regval imx290_10bit_settings[] = {
@@ -522,6 +525,25 @@ static int imx290_write_current_format(struct imx290 *imx290,
 	return 0;
 }
 
+static int imx290_set_hmax(struct imx290 *imx290, u32 val)
+{
+	int ret;
+
+	ret = imx290_write_reg(imx290, IMX290_HMAX_LOW, (val & 0xff));
+	if (ret) {
+		dev_err(imx290->dev, "Error setting HMAX register\n");
+		return ret;
+	}
+
+	ret = imx290_write_reg(imx290, IMX290_HMAX_HIGH, ((val >> 8) & 0xff));
+	if (ret) {
+		dev_err(imx290->dev, "Error setting HMAX register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 /* Start streaming */
 static int imx290_start_streaming(struct imx290 *imx290)
 {
@@ -551,6 +573,40 @@ static int imx290_start_streaming(struct imx290 *imx290)
 		return ret;
 	}
 
+	switch (imx290->nlanes) {
+	case 2:
+		if (imx290->current_mode->width == 1920) {
+			ret = imx290_set_hmax(imx290, IMX290_HMAX_2_1920);
+			if (ret < 0)
+				return ret;
+		} else {
+			ret = imx290_set_hmax(imx290, IMX290_HMAX_2_720);
+			if (ret < 0)
+				return ret;
+		}
+
+		break;
+	case 4:
+		if (imx290->current_mode->width == 1920) {
+			ret = imx290_set_hmax(imx290, IMX290_HMAX_4_1920);
+			if (ret < 0)
+				return ret;
+		} else {
+			ret = imx290_set_hmax(imx290, IMX290_HMAX_4_720);
+			if (ret < 0)
+				return ret;
+		}
+
+		break;
+	default:
+		/*
+		 * We should never hit this since the data lane count is
+		 * validated in probe itself
+		 */
+		dev_err(imx290->dev, "Lane configuration not supported\n");
+		return -EINVAL;
+	}
+
 	/* Apply customized values from user */
 	ret = v4l2_ctrl_handler_setup(imx290->sd.ctrl_handler);
 	if (ret) {
@@ -607,6 +663,49 @@ static int imx290_get_regulators(struct device *dev, struct imx290 *imx290)
 				       imx290->supplies);
 }
 
+static int imx290_set_data_lanes(struct imx290 *imx290)
+{
+	int ret = 0, laneval, frsel;
+
+	switch (imx290->nlanes) {
+	case 2:
+		laneval = 0x01;
+		frsel = 0x02;
+		break;
+	case 4:
+		laneval = 0x03;
+		frsel = 0x01;
+		break;
+	default:
+		/*
+		 * We should never hit this since the data lane count is
+		 * validated in probe itself
+		 */
+		dev_err(imx290->dev, "Lane configuration not supported\n");
+		ret = -EINVAL;
+		goto exit;
+	}
+
+	ret = imx290_write_reg(imx290, IMX290_PHY_LANE_NUM, laneval);
+	if (ret) {
+		dev_err(imx290->dev, "Error setting Physical Lane number register\n");
+		goto exit;
+	}
+
+	ret = imx290_write_reg(imx290, IMX290_CSI_LANE_MODE, laneval);
+	if (ret) {
+		dev_err(imx290->dev, "Error setting CSI Lane mode register\n");
+		goto exit;
+	}
+
+	ret = imx290_write_reg(imx290, IMX290_FR_FDG_SEL, frsel);
+	if (ret)
+		dev_err(imx290->dev, "Error setting FR/FDG SEL register\n");
+
+exit:
+	return ret;
+}
+
 static int imx290_power_on(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -703,6 +802,16 @@ static int imx290_probe(struct i2c_client *client)
 		goto free_err;
 	}
 
+	/* Get number of data lanes */
+	imx290->nlanes = imx290->ep.bus.mipi_csi2.num_data_lanes;
+	if (imx290->nlanes != 2 && imx290->nlanes != 4) {
+		dev_err(dev, "Invalid data lanes: %d\n", imx290->nlanes);
+		ret = -EINVAL;
+		goto free_err;
+	}
+
+	dev_dbg(dev, "Using %u data lanes\n", imx290->nlanes);
+
 	if (!imx290->ep.nr_of_link_frequencies) {
 		dev_err(dev, "link-frequency property not found in DT\n");
 		ret = -EINVAL;
@@ -822,6 +931,9 @@ static int imx290_probe(struct i2c_client *client)
 		goto free_entity;
 	}
 
+	/* Set data lane count */
+	imx290_set_data_lanes(imx290);
+
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);
 	pm_runtime_idle(dev);
-- 
2.17.1