Re: [PATCH v3 04/10] media: i2c: imx290: Add support for 2 data lanes

[Andrey Konovalov]

Hi Sakari,

Thank you for the review

On 26.05.2020 12:01, Sakari Ailus wrote:

Hi Andrey,

On Sun, May 24, 2020 at 10:24:59PM +0300, Andrey Konovalov wrote:

From: Manivannan Sadhasivam <manivannan.sadhasi...@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.sadhasi...@linaro.org>
Signed-off-by: Andrey Konovalov <andrey.konova...@linaro.org>
---
  drivers/media/i2c/imx290.c | 133 ++++++++++++++++++++++++++++++++++---
  1 file changed, 124 insertions(+), 9 deletions(-)

diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
index 7b1de1f0c8b7..a361c9ac8bd5 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;
+       u8 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;

I think it'd be nicer to put this where the mode definitions are, to avoid
scattering the configuration around the driver.

Would it be OK if I move this inside imx290_write_current_format()?

+               }
+
+               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);
@@ -631,6 +730,9 @@ static int imx290_power_on(struct device *dev)
        gpiod_set_value_cansleep(imx290->rst_gpio, 0);
        usleep_range(30000, 31000);

+ /* Set data lane count */

+       imx290_set_data_lanes(imx290);
+
        return 0;
  }

@@ -703,6 +805,16 @@ static int imx290_probe(struct i2c_client *client)

                goto free_err;
        }

+ /* Get number of data lanes */

While at it, could you set the PHY type in the V4L2 fwnode endpoint before
parsing the data using v4l2_fwnode_endpoint_alloc_parse()?

This is currently done in "[PATCH v3 10/10] media: i2c: imx290: set bus_type
before calling v4l2_fwnode_endpoint_alloc_parse()" (along with some more
clean-ups for the probe()). I can merge the PHY type in the V4L2 fwnode endpoint
change into this patch.

Thanks,
Andrey

+       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;
@@ -823,6 +935,9 @@ 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);