[2/2] media: i2c: ov5670: Support single-lane operation

Currently the driver always configures the sensor for dual-lane MIPI
output, but it also supports single-lane output. Add support for that by
checking the data-lanes fwnode property how many lanes are used and
configure the necessary registers based on that.

To achieve this we move setting register 0x3018 out of the general reg
sequence so we set it to the correct value. The pixel_rate value also
needs to be adjusted.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
---
 drivers/media/i2c/ov5670.c | 85 ++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 70 insertions(+), 15 deletions(-)

Hi Luca

On Fri, Feb 10, 2023 at 09:33:18PM +0100, Luca Weiss wrote:
> Currently the driver always configures the sensor for dual-lane MIPI
> output, but it also supports single-lane output. Add support for that by
> checking the data-lanes fwnode property how many lanes are used and
> configure the necessary registers based on that.
>
> To achieve this we move setting register 0x3018 out of the general reg
> sequence so we set it to the correct value. The pixel_rate value also
> needs to be adjusted.

This is not necessary right now as the driver supports a single pixel
rate, but I think it prepares for adding more frequencies, so good to
have it here!

>
> Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
> ---
>  drivers/media/i2c/ov5670.c | 85 ++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 70 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
> index 189920571df2..4ca082455c46 100644
> --- a/drivers/media/i2c/ov5670.c
> +++ b/drivers/media/i2c/ov5670.c
> @@ -29,6 +29,12 @@
>  #define OV5670_REG_SOFTWARE_RST		0x0103
>  #define OV5670_SOFTWARE_RST		0x01
>
> +#define OV5670_MIPI_SC_CTRL0_REG		0x3018
> +#define OV5670_MIPI_SC_CTRL0_LANES(v)		((((v) - 1) << 5) & \
> +						 GENMASK(7, 5))
> +#define OV5670_MIPI_SC_CTRL0_MIPI_EN		BIT(4)
> +#define OV5670_MIPI_SC_CTRL0_RESERVED		BIT(1)
> +
>  /* vertical-timings from sensor */
>  #define OV5670_REG_VTS			0x380e
>  #define OV5670_VTS_30FPS		0x0808 /* default for 30 fps */
> @@ -92,7 +98,6 @@ struct ov5670_reg_list {
>  };
>
>  struct ov5670_link_freq_config {
> -	u32 pixel_rate;
>  	const struct ov5670_reg_list reg_list;
>  };
>
> @@ -163,7 +168,6 @@ static const struct ov5670_reg mode_2592x1944_regs[] = {
>  	{0x3005, 0xf0},
>  	{0x3007, 0x00},
>  	{0x3015, 0x0f},
> -	{0x3018, 0x32},
>  	{0x301a, 0xf0},
>  	{0x301b, 0xf0},
>  	{0x301c, 0xf0},
> @@ -429,7 +433,6 @@ static const struct ov5670_reg mode_1296x972_regs[] = {
>  	{0x3005, 0xf0},
>  	{0x3007, 0x00},
>  	{0x3015, 0x0f},
> -	{0x3018, 0x32},
>  	{0x301a, 0xf0},
>  	{0x301b, 0xf0},
>  	{0x301c, 0xf0},
> @@ -695,7 +698,6 @@ static const struct ov5670_reg mode_648x486_regs[] = {
>  	{0x3005, 0xf0},
>  	{0x3007, 0x00},
>  	{0x3015, 0x0f},
> -	{0x3018, 0x32},
>  	{0x301a, 0xf0},
>  	{0x301b, 0xf0},
>  	{0x301c, 0xf0},
> @@ -961,7 +963,6 @@ static const struct ov5670_reg mode_2560x1440_regs[] = {
>  	{0x3005, 0xf0},
>  	{0x3007, 0x00},
>  	{0x3015, 0x0f},
> -	{0x3018, 0x32},
>  	{0x301a, 0xf0},
>  	{0x301b, 0xf0},
>  	{0x301c, 0xf0},
> @@ -1226,7 +1227,6 @@ static const struct ov5670_reg mode_1280x720_regs[] = {
>  	{0x3005, 0xf0},
>  	{0x3007, 0x00},
>  	{0x3015, 0x0f},
> -	{0x3018, 0x32},
>  	{0x301a, 0xf0},
>  	{0x301b, 0xf0},
>  	{0x301c, 0xf0},
> @@ -1492,7 +1492,6 @@ static const struct ov5670_reg mode_640x360_regs[] = {
>  	{0x3005, 0xf0},
>  	{0x3007, 0x00},
>  	{0x3015, 0x0f},
> -	{0x3018, 0x32},
>  	{0x301a, 0xf0},
>  	{0x301b, 0xf0},
>  	{0x301c, 0xf0},
> @@ -1762,8 +1761,6 @@ static const char * const ov5670_test_pattern_menu[] = {
>  #define OV5670_LINK_FREQ_422MHZ_INDEX	0
>  static const struct ov5670_link_freq_config link_freq_configs[] = {
>  	{
> -		/* pixel_rate = link_freq * 2 * nr_of_lanes / bits_per_sample */
> -		.pixel_rate = (OV5670_LINK_FREQ_422MHZ * 2 * 2) / 10,
>  		.reg_list = {
>  			.num_of_regs = ARRAY_SIZE(mipi_data_rate_840mbps),
>  			.regs = mipi_data_rate_840mbps,
> @@ -1859,6 +1856,7 @@ static const struct ov5670_mode supported_modes[] = {
>  struct ov5670 {
>  	struct v4l2_subdev sd;
>  	struct media_pad pad;
> +	struct v4l2_fwnode_endpoint endpoint;
>
>  	struct v4l2_ctrl_handler ctrl_handler;
>  	/* V4L2 Controls */
> @@ -2101,9 +2099,13 @@ static const struct v4l2_ctrl_ops ov5670_ctrl_ops = {
>  /* Initialize control handlers */
>  static int ov5670_init_controls(struct ov5670 *ov5670)
>  {
> +	struct v4l2_mbus_config_mipi_csi2 *bus_mipi_csi2 =
> +		&ov5670->endpoint.bus.mipi_csi2;
>  	struct i2c_client *client = v4l2_get_subdevdata(&ov5670->sd);
>  	struct v4l2_fwnode_device_properties props;
>  	struct v4l2_ctrl_handler *ctrl_hdlr;
> +	unsigned int lanes_count;
> +	s64 mipi_pixel_rate;
>  	s64 vblank_max;
>  	s64 vblank_def;
>  	s64 vblank_min;
> @@ -2124,12 +2126,15 @@ static int ov5670_init_controls(struct ov5670 *ov5670)
>  		ov5670->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
>
>  	/* By default, V4L2_CID_PIXEL_RATE is read only */
> +	lanes_count = bus_mipi_csi2->num_data_lanes;
> +	mipi_pixel_rate = OV5670_LINK_FREQ_422MHZ * 2 * lanes_count / 10;
> +
>  	ov5670->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &ov5670_ctrl_ops,
>  					       V4L2_CID_PIXEL_RATE,
> -					       link_freq_configs[0].pixel_rate,
> -					       link_freq_configs[0].pixel_rate,
> +					       mipi_pixel_rate,
> +					       mipi_pixel_rate,
>  					       1,
> -					       link_freq_configs[0].pixel_rate);
> +					       mipi_pixel_rate);
>
>  	vblank_max = OV5670_VTS_MAX - ov5670->cur_mode->height;
>  	vblank_def = ov5670->cur_mode->vts_def - ov5670->cur_mode->height;
> @@ -2288,8 +2293,13 @@ static int ov5670_set_pad_format(struct v4l2_subdev *sd,
>  				 struct v4l2_subdev_format *fmt)
>  {
>  	struct ov5670 *ov5670 = to_ov5670(sd);
> +	struct v4l2_mbus_config_mipi_csi2 *bus_mipi_csi2 =
> +		&ov5670->endpoint.bus.mipi_csi2;
>  	const struct ov5670_mode *mode;
> +	unsigned int lanes_count;
> +	s64 mipi_pixel_rate;
>  	s32 vblank_def;
> +	s64 link_freq;
>  	s32 h_blank;
>
>  	mutex_lock(&ov5670->mutex);
> @@ -2306,9 +2316,14 @@ static int ov5670_set_pad_format(struct v4l2_subdev *sd,
>  	} else {
>  		ov5670->cur_mode = mode;
>  		__v4l2_ctrl_s_ctrl(ov5670->link_freq, mode->link_freq_index);
> +
> +		lanes_count = bus_mipi_csi2->num_data_lanes;
> +		link_freq = link_freq_menu_items[mode->link_freq_index];
> +		/* pixel_rate = link_freq * 2 * nr_of_lanes / bits_per_sample */
> +		mipi_pixel_rate = link_freq * 2 * lanes_count / 10;
>  		__v4l2_ctrl_s_ctrl_int64(
>  			ov5670->pixel_rate,
> -			link_freq_configs[mode->link_freq_index].pixel_rate);
> +			mipi_pixel_rate);
>  		/* Update limits and set FPS to default */
>  		vblank_def = ov5670->cur_mode->vts_def -
>  			     ov5670->cur_mode->height;
> @@ -2361,6 +2376,19 @@ static int ov5670_identify_module(struct ov5670 *ov5670)
>  	return 0;
>  }
>
> +static int ov5670_mipi_configure(struct ov5670 *ov5670)
> +{
> +	struct v4l2_mbus_config_mipi_csi2 *bus_mipi_csi2 =
> +		&ov5670->endpoint.bus.mipi_csi2;
> +	unsigned int lanes_count = bus_mipi_csi2->num_data_lanes;
> +
> +	return ov5670_write_reg(ov5670, OV5670_MIPI_SC_CTRL0_REG,
> +				OV5670_REG_VALUE_08BIT,
> +				OV5670_MIPI_SC_CTRL0_LANES(lanes_count) |
> +				OV5670_MIPI_SC_CTRL0_MIPI_EN |
> +				OV5670_MIPI_SC_CTRL0_RESERVED);
> +}
> +
>  /* Prepare streaming by writing default values and customized values */
>  static int ov5670_start_streaming(struct ov5670 *ov5670)
>  {
> @@ -2399,6 +2427,12 @@ static int ov5670_start_streaming(struct ov5670 *ov5670)
>  		return ret;
>  	}
>
> +	ret = ov5670_mipi_configure(ov5670);
> +	if (ret) {
> +		dev_err(&client->dev, "%s failed to configure MIPI\n", __func__);
> +		return ret;
> +	}
> +
>  	ret = __v4l2_ctrl_handler_setup(ov5670->sd.ctrl_handler);
>  	if (ret)
>  		return ret;
> @@ -2647,6 +2681,7 @@ static int ov5670_gpio_probe(struct ov5670 *ov5670)
>
>  static int ov5670_probe(struct i2c_client *client)
>  {
> +	struct fwnode_handle *handle;
>  	struct ov5670 *ov5670;
>  	u32 input_clk = 0;
>  	bool full_power;
> @@ -2683,11 +2718,26 @@ static int ov5670_probe(struct i2c_client *client)
>  	if (ret)
>  		return dev_err_probe(&client->dev, ret, "GPIO probe failed\n");
>
> +	/* Graph Endpoint */
> +	handle = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev), NULL);
> +	if (!handle)
> +		return dev_err_probe(&client->dev, -ENXIO, "Endpoint for node get failed\n");

As commented on the previous patch, I don't think parsing the endpoint
can return -EPROBE_DEFER

> +
> +	ov5670->endpoint.bus_type = V4L2_MBUS_CSI2_DPHY;
> +	ov5670->endpoint.bus.mipi_csi2.num_data_lanes = 2;
> +
> +	ret = v4l2_fwnode_endpoint_alloc_parse(handle, &ov5670->endpoint);
> +	fwnode_handle_put(handle);
> +	if (ret)
> +		return dev_err_probe(&client->dev, ret, "Endpoint parse failed\n");
> +

ditto

>  	full_power = acpi_dev_state_d0(&client->dev);
>  	if (full_power) {
>  		ret = ov5670_runtime_resume(&client->dev);
> -		if (ret)
> -			return dev_err_probe(&client->dev, ret, "Power up failed\n");
> +		if (ret) {
> +			dev_err_probe(&client->dev, ret, "Power up failed\n");
> +			goto error_endpoint;
> +		}
>
>  		/* Check module identity */
>  		ret = ov5670_identify_module(ov5670);
> @@ -2754,6 +2804,9 @@ static int ov5670_probe(struct i2c_client *client)
>  	if (full_power)
>  		ov5670_runtime_suspend(&client->dev);
>
> +error_endpoint:
> +	v4l2_fwnode_endpoint_free(&ov5670->endpoint);
> +
>  	return ret;
>  }
>
> @@ -2769,6 +2822,8 @@ static void ov5670_remove(struct i2c_client *client)
>
>  	pm_runtime_disable(&client->dev);
>  	ov5670_runtime_suspend(&client->dev);
> +
> +	v4l2_fwnode_endpoint_free(&ov5670->endpoint);

Nits apart
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

Thanks
  j

>  }
>
>  static const struct dev_pm_ops ov5670_pm_ops = {
>
> --
> 2.39.1
>