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

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

Hi Sakari,

On Tue, Dec 03, 2019 at 10:45:20AM +0200, Sakari Ailus wrote:
> Hi Manivannan,
> 
> Thanks for the patchset.
> 
> On Sat, Nov 30, 2019 at 12:35:37AM +0530, Manivannan Sadhasivam wrote:
> > 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;
> 
> You're using u8 for another small (unsigned) integer later. How about u8
> here?
> 

Yeah, this is a left over. I was initially trying to use some error
checking with this! Will change it to u8.

> >  
> >  	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);
> 
> The sensor is likely (but not necessarily) about to be powered off here.
> Wouldn't this also belong to be put to the power on sequence?
> 

Agree, will add.

Thanks,
Mani

> > +
> >  	pm_runtime_set_active(dev);
> >  	pm_runtime_enable(dev);
> >  	pm_runtime_idle(dev);
> 
> -- 
> Regards,
> 
> Sakari Ailus