Re: [PATCH v6 2/2] media: i2c: Add imx334 camera sensor driver

Hi Martina,

Thanks for the update.

On Tue, Feb 02, 2021 at 12:50:18PM +0000, Martina Krasteva wrote:

Could you use imx334->vblank_ctrl->val instead of caching it in
imx334->vblank?

+
+		dev_dbg(imx334->dev, "Received vblank %u, new lpfr %u",
+			imx334->vblank,
+			imx334->vblank + imx334->cur_mode->height);
+
+		ret = __v4l2_ctrl_modify_range(imx334->exp_ctrl,
+					       IMX334_EXPOSURE_MIN,
+					       imx334->vblank +
+					       imx334->cur_mode->height -
+					       IMX334_EXPOSURE_OFFSET,
+					       1, IMX334_EXPOSURE_DEFAULT);
+		break;
+	case V4L2_CID_EXPOSURE:
+
+		/* Set controls only if sensor is in power on state */
+		if (!pm_runtime_get_if_in_use(imx334->dev))
+			return 0;
+
+		exposure = ctrl->val;
+		analog_gain = imx334->again_ctrl->val;
+
+		dev_dbg(imx334->dev, "Received exp %u analog gain %u",
+			exposure, analog_gain);
+
+		ret = imx334_update_exp_gain(imx334, exposure, analog_gain);
+
+		pm_runtime_put(imx334->dev);
+
+		break;
+	default:
+		dev_err(imx334->dev, "Invalid control %d", ctrl->id);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+/* V4l2 subdevice control ops*/
+static const struct v4l2_ctrl_ops imx334_ctrl_ops = {
+	.s_ctrl = imx334_set_ctrl,
+};
+
+/**
+ * imx334_enum_mbus_code() - Enumerate V4L2 sub-device mbus codes
+ * @sd: pointer to imx334 V4L2 sub-device structure
+ * @cfg: V4L2 sub-device pad configuration
+ * @code: V4L2 sub-device code enumeration need to be filled
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_enum_mbus_code(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_pad_config *cfg,
+				 struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->index > 0)
+		return -EINVAL;
+
+	code->code = supported_mode.code;
+
+	return 0;
+}
+
+/**
+ * imx334_enum_frame_size() - Enumerate V4L2 sub-device frame sizes
+ * @sd: pointer to imx334 V4L2 sub-device structure
+ * @cfg: V4L2 sub-device pad configuration
+ * @fsize: V4L2 sub-device size enumeration need to be filled
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_enum_frame_size(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_pad_config *cfg,
+				  struct v4l2_subdev_frame_size_enum *fsize)
+{
+	if (fsize->index > 0)
+		return -EINVAL;
+
+	if (fsize->code != supported_mode.code)
+		return -EINVAL;
+
+	fsize->min_width = supported_mode.width;
+	fsize->max_width = fsize->min_width;
+	fsize->min_height = supported_mode.height;
+	fsize->max_height = fsize->min_height;
+
+	return 0;
+}
+
+/**
+ * imx334_fill_pad_format() - Fill subdevice pad format
+ *                            from selected sensor mode
+ * @imx334: pointer to imx334 device
+ * @mode: pointer to imx334_mode sensor mode
+ * @fmt: V4L2 sub-device format need to be filled
+ */
+static void imx334_fill_pad_format(struct imx334 *imx334,
+				   const struct imx334_mode *mode,
+				   struct v4l2_subdev_format *fmt)
+{
+	fmt->format.width = mode->width;
+	fmt->format.height = mode->height;
+	fmt->format.code = mode->code;
+	fmt->format.field = V4L2_FIELD_NONE;
+	fmt->format.colorspace = V4L2_COLORSPACE_RAW;
+	fmt->format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
+	fmt->format.quantization = V4L2_QUANTIZATION_DEFAULT;
+	fmt->format.xfer_func = V4L2_XFER_FUNC_NONE;
+}
+
+/**
+ * imx334_get_pad_format() - Get subdevice pad format
+ * @sd: pointer to imx334 V4L2 sub-device structure
+ * @cfg: V4L2 sub-device pad configuration
+ * @fmt: V4L2 sub-device format need to be set
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_get_pad_format(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_pad_config *cfg,
+				 struct v4l2_subdev_format *fmt)
+{
+	struct imx334 *imx334 = to_imx334(sd);
+
+	mutex_lock(&imx334->mutex);
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		struct v4l2_mbus_framefmt *framefmt;
+
+		framefmt = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
+		fmt->format = *framefmt;
+	} else {
+		imx334_fill_pad_format(imx334, imx334->cur_mode, fmt);
+	}
+
+	mutex_unlock(&imx334->mutex);
+
+	return 0;
+}
+
+/**
+ * imx334_set_pad_format() - Set subdevice pad format
+ * @sd: pointer to imx334 V4L2 sub-device structure
+ * @cfg: V4L2 sub-device pad configuration
+ * @fmt: V4L2 sub-device format need to be set
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_set_pad_format(struct v4l2_subdev *sd,
+				 struct v4l2_subdev_pad_config *cfg,
+				 struct v4l2_subdev_format *fmt)
+{
+	struct imx334 *imx334 = to_imx334(sd);
+	const struct imx334_mode *mode;
+	int ret = 0;
+
+	mutex_lock(&imx334->mutex);
+
+	mode = &supported_mode;
+	imx334_fill_pad_format(imx334, mode, fmt);
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		struct v4l2_mbus_framefmt *framefmt;
+
+		framefmt = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
+		*framefmt = fmt->format;
+	} else {
+		ret = __v4l2_ctrl_s_ctrl(imx334->hblank_ctrl, mode->hblank);
+		if (ret)
+			return ret;
+
+		ret = __v4l2_ctrl_modify_range(imx334->vblank_ctrl,
+					       mode->vblank_min,
+					       mode->vblank_max,
+					       1, mode->vblank);
+		if (ret)
+			return ret;

You're returning without releasing the mutex here.

How about simply making the assignment below if ret is zero?

+
+		imx334->cur_mode = mode;
+	}
+
+	mutex_unlock(&imx334->mutex);
+
+	return ret;
+}
+
+/**
+ * imx334_init_pad_cfg() - Initialize sub-device pad configuration
+ * @sd: pointer to imx334 V4L2 sub-device structure
+ * @cfg: V4L2 sub-device pad configuration
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_init_pad_cfg(struct v4l2_subdev *sd,
+			       struct v4l2_subdev_pad_config *cfg)
+{
+	struct imx334 *imx334 = to_imx334(sd);
+	struct v4l2_subdev_format fmt = { 0 };
+
+	fmt.which = cfg ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
+	imx334_fill_pad_format(imx334, &supported_mode, &fmt);
+
+	return imx334_set_pad_format(sd, cfg, &fmt);
+}
+
+/**
+ * imx334_start_streaming() - Start sensor stream
+ * @imx334: pointer to imx334 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_start_streaming(struct imx334 *imx334)
+{
+	const struct imx334_reg_list *reg_list;
+	int ret;
+
+	/* Write sensor mode registers */
+	reg_list = &imx334->cur_mode->reg_list;
+	ret = imx334_write_regs(imx334, reg_list->regs,
+				reg_list->num_of_regs);
+	if (ret) {
+		dev_err(imx334->dev, "fail to write initial registers");
+		return ret;
+	}
+
+	/* Setup handler will write actual exposure and gain */
+	ret =  __v4l2_ctrl_handler_setup(imx334->sd.ctrl_handler);
+	if (ret) {
+		dev_err(imx334->dev, "fail to setup handler");
+		return ret;
+	}
+
+	/* Start streaming */
+	ret = imx334_write_reg(imx334, IMX334_REG_MODE_SELECT,
+			       1, IMX334_MODE_STREAMING);
+	if (ret) {
+		dev_err(imx334->dev, "fail to start streaming");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * imx334_stop_streaming() - Stop sensor stream
+ * @imx334: pointer to imx334 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_stop_streaming(struct imx334 *imx334)
+{
+	return imx334_write_reg(imx334, IMX334_REG_MODE_SELECT,
+				1, IMX334_MODE_STANDBY);
+}
+
+/**
+ * imx334_set_stream() - Enable sensor streaming
+ * @sd: pointer to imx334 subdevice
+ * @enable: set to enable sensor streaming
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_set_stream(struct v4l2_subdev *sd, int enable)
+{
+	struct imx334 *imx334 = to_imx334(sd);
+	int ret;
+
+	mutex_lock(&imx334->mutex);
+
+	if (imx334->streaming == enable) {
+		mutex_unlock(&imx334->mutex);
+		return 0;
+	}
+
+	if (enable) {
+		ret = pm_runtime_get_sync(imx334->dev);
+		if (ret)
+			goto error_power_off;
+
+		ret = imx334_start_streaming(imx334);
+		if (ret)
+			goto error_power_off;
+	} else {
+		imx334_stop_streaming(imx334);
+		pm_runtime_put(imx334->dev);
+	}
+
+	imx334->streaming = enable;
+
+	mutex_unlock(&imx334->mutex);
+
+	return 0;
+
+error_power_off:
+	pm_runtime_put(imx334->dev);
+	mutex_unlock(&imx334->mutex);
+
+	return ret;
+}
+
+/**
+ * imx334_detect() - Detect imx334 sensor
+ * @imx334: pointer to imx334 device
+ *
+ * Return: 0 if successful, -EIO if sensor id does not match
+ */
+static int imx334_detect(struct imx334 *imx334)
+{
+	int ret;
+	u32 val;
+
+	ret = imx334_read_reg(imx334, IMX334_REG_ID, 2, &val);
+	if (ret)
+		return ret;
+
+	if (val != IMX334_ID) {
+		dev_err(imx334->dev, "chip id mismatch: %x!=%x",
+			IMX334_ID, val);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+/**
+ * imx334_parse_hw_config() - Parse HW configuration and check if supported
+ * @imx334: pointer to imx334 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_parse_hw_config(struct imx334 *imx334)
+{
+	struct fwnode_handle *fwnode = dev_fwnode(imx334->dev);
+	struct v4l2_fwnode_endpoint bus_cfg = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY
+	};
+	struct fwnode_handle *ep;
+	unsigned long rate;
+	int ret;
+	int i;
+
+	if (!fwnode)
+		return -ENXIO;
+
+	/* Request optional reset pin */
+	imx334->reset_gpio = devm_gpiod_get_optional(imx334->dev, "reset",
+						     GPIOD_OUT_LOW);
+	if (IS_ERR(imx334->reset_gpio)) {
+		dev_err(imx334->dev, "failed to get reset gpio %d", ret);
+		return PTR_ERR(imx334->reset_gpio);
+	}
+
+	/* Get sensor input clock */
+	imx334->inclk = devm_clk_get(imx334->dev, "inclk");
+	if (IS_ERR(imx334->inclk)) {
+		dev_err(imx334->dev, "could not get inclk");
+		return PTR_ERR(imx334->inclk);
+	}
+
+	rate = clk_get_rate(imx334->inclk);
+	if (rate != IMX334_INCLK_RATE) {
+		dev_err(imx334->dev, "inclk frequency mismatch");
+		return -EINVAL;
+	}
+
+	ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
+	if (!ep)
+		return -ENXIO;
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
+	fwnode_handle_put(ep);
+	if (ret)
+		return ret;
+
+	if (bus_cfg.bus.mipi_csi2.num_data_lanes != IMX334_NUM_DATA_LANES) {
+		dev_err(imx334->dev,
+			"number of CSI2 data lanes %d is not supported",
+			bus_cfg.bus.mipi_csi2.num_data_lanes);
+		ret = -EINVAL;
+		goto done_endpoint_free;
+	}
+
+	if (!bus_cfg.nr_of_link_frequencies) {
+		dev_err(imx334->dev, "no link frequencies defined");
+		ret = -EINVAL;
+		goto done_endpoint_free;
+	}
+
+	for (i = 0; i < bus_cfg.nr_of_link_frequencies; i++)
+		if (bus_cfg.link_frequencies[i] == IMX334_LINK_FREQ)
+			goto done_endpoint_free;

Could you also add the LINK_FREQ control? Many bridge and ISP drivers are
using it for configuring the CSI-2 receiver.

Please see:

<URL:https://hverkuil.home.xs4all.nl/spec/driver-api/camera-sensor.html#controls>

The PIXEL_RATE controls should reflect actually the pixel rate on the pixel
array. I'll send a patch to update the documentation.

+
+	ret = -EINVAL;
+
+done_endpoint_free:
+	v4l2_fwnode_endpoint_free(&bus_cfg);
+
+	return ret;
+}
+
+/* V4l2 subdevice ops */
+static const struct v4l2_subdev_video_ops imx334_video_ops = {
+	.s_stream = imx334_set_stream,
+};
+
+static const struct v4l2_subdev_pad_ops imx334_pad_ops = {
+	.init_cfg = imx334_init_pad_cfg,
+	.enum_mbus_code = imx334_enum_mbus_code,
+	.enum_frame_size = imx334_enum_frame_size,
+	.get_fmt = imx334_get_pad_format,
+	.set_fmt = imx334_set_pad_format,
+};
+
+static const struct v4l2_subdev_ops imx334_subdev_ops = {
+	.video = &imx334_video_ops,
+	.pad = &imx334_pad_ops,
+};
+
+/**
+ * imx334_power_on() - Sensor power on sequence
+ * @dev: pointer to i2c device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_power_on(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct imx334 *imx334 = to_imx334(sd);
+	int ret;
+
+	gpiod_set_value_cansleep(imx334->reset_gpio, 1);
+
+	ret = clk_prepare_enable(imx334->inclk);
+	if (ret) {
+		dev_err(imx334->dev, "fail to enable inclk");
+		goto error_reset;
+	}
+
+	usleep_range(18000, 20000);
+
+	return 0;
+
+error_reset:
+	gpiod_set_value_cansleep(imx334->reset_gpio, 0);
+
+	return ret;
+}
+
+/**
+ * imx334_power_off() - Sensor power off sequence
+ * @dev: pointer to i2c device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_power_off(struct device *dev)
+{
+	struct v4l2_subdev *sd = dev_get_drvdata(dev);
+	struct imx334 *imx334 = to_imx334(sd);
+
+	gpiod_set_value_cansleep(imx334->reset_gpio, 0);
+
+	clk_disable_unprepare(imx334->inclk);
+
+	return 0;
+}
+
+/**
+ * imx334_init_controls() - Initialize sensor subdevice controls
+ * @imx334: pointer to imx334 device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_init_controls(struct imx334 *imx334)
+{
+	struct v4l2_ctrl_handler *ctrl_hdlr = &imx334->ctrl_handler;
+	const struct imx334_mode *mode = imx334->cur_mode;
+	u32 lpfr;
+	int ret;
+
+	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 5);
+	if (ret)
+		return ret;
+
+	/* Serialize controls with sensor device */
+	ctrl_hdlr->lock = &imx334->mutex;
+
+	/* Initialize exposure and gain */
+	lpfr = mode->vblank + mode->height;
+	imx334->exp_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+					     &imx334_ctrl_ops,
+					     V4L2_CID_EXPOSURE,
+					     IMX334_EXPOSURE_MIN,
+					     lpfr - IMX334_EXPOSURE_OFFSET,
+					     IMX334_EXPOSURE_STEP,
+					     IMX334_EXPOSURE_DEFAULT);
+
+	imx334->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+					       &imx334_ctrl_ops,
+					       V4L2_CID_ANALOGUE_GAIN,
+					       IMX334_AGAIN_MIN,
+					       IMX334_AGAIN_MAX,
+					       IMX334_AGAIN_STEP,
+					       IMX334_AGAIN_DEFAULT);
+
+	v4l2_ctrl_cluster(2, &imx334->exp_ctrl);
+
+	imx334->vblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+						&imx334_ctrl_ops,
+						V4L2_CID_VBLANK,
+						mode->vblank_min,
+						mode->vblank_max,
+						1, mode->vblank);
+
+	/* Read only controls */
+	imx334->pclk_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+					      &imx334_ctrl_ops,
+					      V4L2_CID_PIXEL_RATE,
+					      mode->pclk, mode->pclk,
+					      1, mode->pclk);
+
+	imx334->hblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
+						&imx334_ctrl_ops,
+						V4L2_CID_HBLANK,
+						IMX334_REG_MIN,
+						IMX334_REG_MAX,
+						1, mode->hblank);
+	if (imx334->hblank_ctrl)
+		imx334->hblank_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	if (ctrl_hdlr->error) {
+		dev_err(imx334->dev, "control init failed: %d",
+			ctrl_hdlr->error);
+		v4l2_ctrl_handler_free(ctrl_hdlr);
+		return ctrl_hdlr->error;
+	}
+
+	imx334->sd.ctrl_handler = ctrl_hdlr;
+
+	return 0;
+}
+
+/**
+ * imx334_probe() - I2C client device binding
+ * @client: pointer to i2c client device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_probe(struct i2c_client *client)
+{
+	struct imx334 *imx334;
+	int ret;
+
+	imx334 = devm_kzalloc(&client->dev, sizeof(*imx334), GFP_KERNEL);
+	if (!imx334)
+		return -ENOMEM;
+
+	imx334->dev = &client->dev;
+
+	/* Initialize subdev */
+	v4l2_i2c_subdev_init(&imx334->sd, client, &imx334_subdev_ops);
+
+	ret = imx334_parse_hw_config(imx334);
+	if (ret) {
+		dev_err(imx334->dev, "HW configuration is not supported");
+		return ret;
+	}
+
+	mutex_init(&imx334->mutex);
+
+	ret = imx334_power_on(imx334->dev);
+	if (ret) {
+		dev_err(imx334->dev, "failed to power-on the sensor");
+		goto error_mutex_destroy;
+	}
+
+	/* Check module identity */
+	ret = imx334_detect(imx334);
+	if (ret) {
+		dev_err(imx334->dev, "failed to find sensor: %d", ret);
+		goto error_power_off;
+	}
+
+	/* Set default mode to max resolution */
+	imx334->cur_mode = &supported_mode;
+	imx334->vblank = imx334->cur_mode->vblank;
+
+	ret = imx334_init_controls(imx334);
+	if (ret) {
+		dev_err(imx334->dev, "failed to init controls: %d", ret);
+		goto error_power_off;
+	}
+
+	/* Initialize subdev */
+	imx334->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	imx334->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
+
+	/* Initialize source pad */
+	imx334->pad.flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&imx334->sd.entity, 1, &imx334->pad);
+	if (ret) {
+		dev_err(imx334->dev, "failed to init entity pads: %d", ret);
+		goto error_handler_free;
+	}
+
+	ret = v4l2_async_register_subdev_sensor_common(&imx334->sd);
+	if (ret < 0) {
+		dev_err(imx334->dev,
+			"failed to register async subdev: %d", ret);
+		goto error_media_entity;
+	}
+
+	pm_runtime_set_active(imx334->dev);
+	pm_runtime_enable(imx334->dev);
+	pm_runtime_idle(imx334->dev);
+
+	return 0;
+
+error_media_entity:
+	media_entity_cleanup(&imx334->sd.entity);
+error_handler_free:
+	v4l2_ctrl_handler_free(imx334->sd.ctrl_handler);
+error_power_off:
+	imx334_power_off(imx334->dev);
+error_mutex_destroy:
+	mutex_destroy(&imx334->mutex);
+
+	return ret;
+}
+
+/**
+ * imx334_remove() - I2C client device unbinding
+ * @client: pointer to I2C client device
+ *
+ * Return: 0 if successful, error code otherwise.
+ */
+static int imx334_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct imx334 *imx334 = to_imx334(sd);
+
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(sd->ctrl_handler);
+
+	pm_runtime_disable(&client->dev);
+	pm_runtime_suspended(&client->dev);
+
+	mutex_destroy(&imx334->mutex);
+
+	return 0;
+}
+
+static const struct dev_pm_ops imx334_pm_ops = {
+	SET_RUNTIME_PM_OPS(imx334_power_off, imx334_power_on, NULL)
+};
+
+static const struct of_device_id imx334_of_match[] = {
+	{ .compatible = "sony,imx334" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, imx334_of_match);
+
+static struct i2c_driver imx334_driver = {
+	.probe_new = imx334_probe,
+	.remove = imx334_remove,
+	.driver = {
+		.name = "imx334",
+		.pm = &imx334_pm_ops,
+		.of_match_table = imx334_of_match,
+	},
+};
+
+module_i2c_driver(imx334_driver);
+
+MODULE_DESCRIPTION("Sony imx334 sensor driver");
+MODULE_LICENSE("GPL");

-- 
Kind regards,

Sakari Ailus