Re: [PATCH v6 4/4] media: i2c: Add driver for ST VGXY61 camera sensor

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Benjamin,

On Fri, Oct 07, 2022 at 02:38:33PM +0200, Benjamin MUGNIER wrote:
> On 10/7/22 14:32, Laurent Pinchart wrote:
> > On Fri, Oct 07, 2022 at 02:24:16PM +0200, Benjamin MUGNIER wrote:
> >> Hi Sakari,
> >>
> >> Thank you for your review.
> >> Please consider everything not commented as queued for v7.
> >>
> >> On 10/6/22 21:14, Sakari Ailus wrote:
> >>> Hi Benjamin,
> >>>
> >>> Thanks for the update. A few more comments below...
> >>>
> >>> On Tue, Sep 27, 2022 at 10:37:02AM +0200, Benjamin Mugnier wrote:
> >>>> +static const char * const vgxy61_hdr_mode_menu[] = {
> >>>> +	"HDR linearize",
> >>>> +	"HDR substraction",
> >>>> +	"No HDR",
> >>>> +};
> >>>
> >>> I think more documentation is needed on the HDR modes. What do these mean?
> >>> For instance, are they something that requires further processing or is the
> >>> result e.g. a ready HDR image?
> >>>
> >>> This should probably make it to driver specific documentation.
> >>
> >> Sure, in fact I did something like this in v3:
> >> https://lore.kernel.org/linux-media/20220512074037.3829926-4-benjamin.mugnier@foss.st.com/
> >>
> >> Since I standardized the control I was unsure what to do with this
> >> documentation, and dropped it.
> >>
> >> I will add back the
> >> Documentation/userspace-api/media/drivers/st-vgxy61.rst file from this
> >> commit to the patchset, while changing the control name to the new
> >> one.
> > 
> > The documentation there is about modes for HDR merge on the sensor side.
> > Can the sensor also output the unmerged images, for instance
> > line-interleaved ?
> 
> The sensor can not output unmerged images. It can only output a single
> image and frame merging as to be done sensor side.

I wonder then, should we have two HDR mode controls, one for sensor-side
HDR, and one to control the interleaving of images for host-side HDR ?
The latter would need some standardization I think, as the ISP
configuration needs to match, so there must be some industry de-facto
standards.

> >>>> +
> >>>> +static const char * const vgxy61_supply_name[] = {
> >>>> +	"VCORE",
> >>>> +	"VDDIO",
> >>>> +	"VANA",
> >>>> +};
> >>>> +
> >>>> +#define VGXY61_NUM_SUPPLIES		ARRAY_SIZE(vgxy61_supply_name)
> >>>
> >>> Please use plain ARRAY_SIZE() instead.
> >>>
> >>> ...
> >>>
> >>>> +static int vgxy61_poll_reg(struct vgxy61_dev *sensor, u32 reg, u8 poll_val,
> >>>> +			   unsigned int timeout_ms)
> >>>> +{
> >>>> +	const unsigned int loop_delay_ms = 10;
> >>>> +	int ret, timeout;
> >>>> +
> >>>> +	timeout = read_poll_timeout(vgxy61_read_reg, ret,
> >>>> +				    ((ret < 0) || (ret == poll_val)),
> >>>> +				    loop_delay_ms * 1000, timeout_ms * 1000,
> >>>> +				    false, sensor, reg);
> >>>> +	if (timeout)
> >>>> +		return timeout;
> >>>> +
> >>>> +	return 0;
> >>>
> >>> "timeout" here is entirely pointless.
> >>>
> >>>> +}
> >>>
> >>> ...
> >>>
> >>>> +static int vgxy61_apply_exposure(struct vgxy61_dev *sensor)
> >>>> +{
> >>>> +	int ret = 0;
> >>>> +
> >>>> +	 /* We first set expo to zero to avoid forbidden parameters couple */
> >>>> +	ret = vgxy61_write_reg(sensor, VGXY61_REG_COARSE_EXPOSURE_SHORT,
> >>>> +			       0, &ret);
> >>>> +	ret = vgxy61_write_reg(sensor, VGXY61_REG_COARSE_EXPOSURE_LONG,
> >>>> +			       sensor->expo_long, &ret);
> >>>> +	ret = vgxy61_write_reg(sensor, VGXY61_REG_COARSE_EXPOSURE_SHORT,
> >>>> +			       sensor->expo_short, &ret);
> >>>
> >>> return vgxy61_write_reg(...);
> >>>
> >>>> +	if (ret)
> >>>> +		return ret;
> >>>> +
> >>>> +	return 0;
> >>>> +}
> >>>
> >>> ...
> >>>
> >>>> +static int vgxy61_init_controls(struct vgxy61_dev *sensor)
> >>>> +{
> >>>> +	const struct v4l2_ctrl_ops *ops = &vgxy61_ctrl_ops;
> >>>> +	struct v4l2_ctrl_handler *hdl = &sensor->ctrl_handler;
> >>>> +	const struct vgxy61_mode_info *cur_mode = sensor->current_mode;
> >>>> +	struct v4l2_ctrl *ctrl;
> >>>> +	int ret;
> >>>> +
> >>>> +	v4l2_ctrl_handler_init(hdl, 16);
> >>>> +	/* We can use our own mutex for the ctrl lock */
> >>>> +	hdl->lock = &sensor->lock;
> >>>> +	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_ANALOGUE_GAIN, 0, 0x1c, 1,
> >>>> +			  sensor->analog_gain);
> >>>> +	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_DIGITAL_GAIN, 0, 0xfff, 1,
> >>>> +			  sensor->digital_gain);
> >>>> +	v4l2_ctrl_new_std_menu_items(hdl, ops, V4L2_CID_TEST_PATTERN,
> >>>> +				     ARRAY_SIZE(vgxy61_test_pattern_menu) - 1,
> >>>> +				     0, 0, vgxy61_test_pattern_menu);
> >>>> +	ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_HBLANK, 0,
> >>>> +				 sensor->line_length, 1,
> >>>> +				 sensor->line_length - cur_mode->width);
> >>>> +	if (ctrl)
> >>>> +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >>>> +	ctrl = v4l2_ctrl_new_int_menu(hdl, ops, V4L2_CID_LINK_FREQ,
> >>>> +				      ARRAY_SIZE(link_freq) - 1, 0, link_freq);
> >>>> +	if (ctrl)
> >>>> +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >>>> +	v4l2_ctrl_new_std_menu_items(hdl, ops, V4L2_CID_HDR_MODE,
> >>>> +				     ARRAY_SIZE(vgxy61_hdr_mode_menu) - 1, 0,
> >>>> +				     VGXY61_NO_HDR, vgxy61_hdr_mode_menu);
> >>>> +
> >>>> +	/*
> >>>> +	 * Keep a pointer to these controls as we need to update them when
> >>>> +	 * setting the format
> >>>> +	 */
> >>>> +	sensor->pixel_rate_ctrl = v4l2_ctrl_new_std(hdl, ops,
> >>>> +						    V4L2_CID_PIXEL_RATE, 1,
> >>>> +						    INT_MAX, 1,
> >>>> +						    get_pixel_rate(sensor));
> >>>> +	sensor->pixel_rate_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> >>>
> >>> Also sensor->pixel_rate_ctrl may be NULL here.
> >>>
> >>>> +	sensor->expo_ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_EXPOSURE,
> >>>> +					      sensor->expo_min,
> >>>> +					      sensor->expo_max, 1,
> >>>> +					      sensor->expo_long);
> >>>> +	sensor->vblank_ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_VBLANK,
> >>>> +						sensor->vblank_min,
> >>>> +						0xffff - cur_mode->crop.height,
> >>>> +						1, sensor->vblank);
> >>>> +	sensor->vflip_ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_VFLIP,
> >>>> +					       0, 1, 1, sensor->vflip);
> >>>> +	sensor->hflip_ctrl = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_HFLIP,
> >>>> +					       0, 1, 1, sensor->hflip);
> >>>> +
> >>>> +	if (hdl->error) {
> >>>> +		ret = hdl->error;
> >>>> +		goto free_ctrls;
> >>>> +	}
> >>>> +
> >>>> +	sensor->sd.ctrl_handler = hdl;
> >>>> +	return 0;
> >>>> +
> >>>> +free_ctrls:
> >>>> +	v4l2_ctrl_handler_free(hdl);
> >>>> +	return ret;
> >>>> +}
> >>>
> >>> ...
> >>>
> >>>> +static int vgxy61_probe(struct i2c_client *client)
> >>>> +{
> >>>> +	struct device *dev = &client->dev;
> >>>> +	struct fwnode_handle *handle;
> >>>> +	struct vgxy61_dev *sensor;
> >>>> +	int ret;
> >>>> +
> >>>> +	sensor = devm_kzalloc(dev, sizeof(*sensor), GFP_KERNEL);
> >>>> +	if (!sensor)
> >>>> +		return -ENOMEM;
> >>>> +
> >>>> +	sensor->i2c_client = client;
> >>>> +	sensor->streaming = false;
> >>>> +	sensor->hdr = VGXY61_NO_HDR;
> >>>> +	sensor->expo_long = 200;
> >>>> +	sensor->expo_short = 0;
> >>>> +	sensor->hflip = false;
> >>>> +	sensor->vflip = false;
> >>>> +	sensor->analog_gain = 0;
> >>>> +	sensor->digital_gain = 256;
> >>>> +
> >>>> +	handle = fwnode_graph_get_next_endpoint(of_fwnode_handle(dev->of_node),
> >>>> +						NULL);
> >>>
> >>> handle = fwnode_graph_get_endpoint_by_id(dev_fwnode(dev), 0, 0, 0);
> >>>
> >>>> +	if (!handle) {
> >>>> +		dev_err(dev, "handle node not found\n");
> >>>> +		return -EINVAL;
> >>>> +	}
> >>>> +
> >>>> +	ret = vgxy61_tx_from_ep(sensor, handle);
> >>>> +	fwnode_handle_put(handle);
> >>>> +	if (ret) {
> >>>> +		dev_err(dev, "Failed to parse handle %d\n", ret);
> >>>> +		return ret;
> >>>> +	}
> >>>> +
> >>>> +	sensor->xclk = devm_clk_get(dev, NULL);
> >>>> +	if (IS_ERR(sensor->xclk)) {
> >>>> +		dev_err(dev, "failed to get xclk\n");
> >>>> +		return PTR_ERR(sensor->xclk);
> >>>> +	}
> >>>> +	sensor->clk_freq = clk_get_rate(sensor->xclk);
> >>>> +	if (sensor->clk_freq < 6 * HZ_PER_MHZ ||
> >>>> +	    sensor->clk_freq > 27 * HZ_PER_MHZ) {
> >>>> +		dev_err(dev, "Only 6Mhz-27Mhz clock range supported. provide %lu MHz\n",
> >>>> +			sensor->clk_freq / HZ_PER_MHZ);
> >>>> +		return -EINVAL;
> >>>> +	}
> >>>> +	sensor->gpios_polarity = of_property_read_bool(dev->of_node,
> >>>> +						       "invert-gpios-polarity");
> >>>
> >>> I thought we did discuss dropping support for sensor synchronisation in
> >>> this version?
> >>
> >> This properties affects strobing lights gpios polarities as you can
> >> see in vgxy61_update_gpios_strobe_polarity. If set to '1' all strobing
> >> gpios are inverted. This has nothing to do with the sensor
> >> synchronization.
> >>
> >> Now I realize this is poorly named, and I even forgot to document it
> >> in the device tree bindings file. I apologize.
> >>
> >> I would like to rename it to 'st,strobe-polarity' since this is vendor
> >> specific and to better reflect that it affects strobing gpios.
> >> I'll make this change for v7 and document this in the bindings file
> >> too. Tell me if there is any issues with that.
> >>
> >>>> +
> >>>> +	v4l2_i2c_subdev_init(&sensor->sd, client, &vgxy61_subdev_ops);
> >>>> +	sensor->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> >>>> +	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
> >>>> +	sensor->sd.entity.ops = &vgxy61_subdev_entity_ops;
> >>>> +	sensor->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> >>>> +
> >>>> +	sensor->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> >>>> +						     GPIOD_OUT_HIGH);
> >>>> +
> >>>> +	ret = vgxy61_get_regulators(sensor);
> >>>> +	if (ret) {
> >>>> +		dev_err(&client->dev, "failed to get regulators %d\n", ret);
> >>>> +		return ret;
> >>>> +	}
> >>>> +
> >>>> +	ret = regulator_bulk_enable(VGXY61_NUM_SUPPLIES, sensor->supplies);
> >>>> +	if (ret) {
> >>>> +		dev_err(&client->dev, "failed to enable regulators %d\n", ret);
> >>>> +		return ret;
> >>>> +	}
> >>>> +
> >>>> +	ret = vgxy61_power_on(dev);
> >>>> +	if (ret)
> >>>> +		return ret;
> >>>> +
> >>>> +	ret = vgxy61_detect(sensor);
> >>>> +	if (ret) {
> >>>> +		dev_err(&client->dev, "sensor detect failed %d\n", ret);
> >>>> +		return ret;
> >>>> +	}
> >>>> +
> >>>> +	vgxy61_fill_sensor_param(sensor);
> >>>> +	vgxy61_fill_framefmt(sensor, sensor->current_mode, &sensor->fmt,
> >>>> +			     VGXY61_MEDIA_BUS_FMT_DEF);
> >>>> +
> >>>> +	ret = vgxy61_update_hdr(sensor, sensor->hdr);
> >>>> +	if (ret)
> >>>> +		return ret;
> >>>> +
> >>>> +	mutex_init(&sensor->lock);
> >>>> +
> >>>> +	ret = vgxy61_init_controls(sensor);
> >>>> +	if (ret) {
> >>>> +		dev_err(&client->dev, "controls initialization failed %d\n",
> >>>> +			ret);
> >>>> +		goto error_power_off;
> >>>> +	}
> >>>> +
> >>>> +	ret = media_entity_pads_init(&sensor->sd.entity, 1, &sensor->pad);
> >>>> +	if (ret) {
> >>>> +		dev_err(&client->dev, "pads init failed %d\n", ret);
> >>>> +		goto error_handler_free;
> >>>> +	}
> >>>> +
> >>>> +	/* Enable runtime PM and turn off the device */
> >>>> +	pm_runtime_set_active(dev);
> >>>> +	pm_runtime_enable(dev);
> >>>> +	pm_runtime_idle(dev);
> >>>> +
> >>>> +	ret = v4l2_async_register_subdev(&sensor->sd);
> >>>> +	if (ret) {
> >>>> +		dev_err(&client->dev, "async subdev register failed %d\n", ret);
> >>>> +		goto error_pm_runtime;
> >>>> +	}
> >>>> +
> >>>> +	pm_runtime_set_autosuspend_delay(&client->dev, 1000);
> >>>> +	pm_runtime_use_autosuspend(&client->dev);
> >>>> +
> >>>> +	dev_dbg(&client->dev, "vgxy61 probe successfully\n");
> >>>> +
> >>>> +	return 0;
> >>>> +
> >>>> +error_pm_runtime:
> >>>> +	pm_runtime_disable(&client->dev);
> >>>> +	pm_runtime_set_suspended(&client->dev);
> >>>> +	media_entity_cleanup(&sensor->sd.entity);
> >>>> +error_handler_free:
> >>>> +	v4l2_ctrl_handler_free(sensor->sd.ctrl_handler);
> >>>> +	mutex_destroy(&sensor->lock);
> >>>> +error_power_off:
> >>>> +	vgxy61_power_off(dev);
> >>>> +
> >>>> +	return ret;
> >>>> +}
> > 

-- 
Regards,

Laurent Pinchart