[V10,2/2] media: i2c: ov02a10: Add OV02A10 image sensor driver

Commit Message

Dongchun Zhu June 15, 2020, 12:29 p.m. UTC

Add a V4L2 sub-device driver for OV02A10 image sensor.

Signed-off-by: Dongchun Zhu <[e-mail]>
---
 MAINTAINERS                 |    1 +
 drivers/media/i2c/Kconfig   |   13 +
 drivers/media/i2c/Makefile  |    1 +
 drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 1057 insertions(+)
 create mode 100644 drivers/media/i2c/ov02a10.c

Comments

Tomasz Figa June 18, 2020, 7:10 p.m. UTC | #1

Hi Dongchun,

On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> Add a V4L2 sub-device driver for OV02A10 image sensor.
> 
> Signed-off-by: Dongchun Zhu <[e-mail]>
> ---
>  MAINTAINERS                 |    1 +
>  drivers/media/i2c/Kconfig   |   13 +
>  drivers/media/i2c/Makefile  |    1 +
>  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 1057 insertions(+)
>  create mode 100644 drivers/media/i2c/ov02a10.c
> 

Thank you for the patch. Please see my comments inline.

[snip]
> +static int ov02a10_set_fmt(struct v4l2_subdev *sd,
> +			   struct v4l2_subdev_pad_config *cfg,
> +			   struct v4l2_subdev_format *fmt)
> +{
> +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> +	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> +
> +	mutex_lock(&ov02a10->mutex);
> +
> +	if (ov02a10->streaming) {
> +		mutex_unlock(&ov02a10->mutex);
> +		return -EBUSY;
> +	}
> +
> +	/* Only one sensor mode supported */
> +	mbus_fmt->code = ov02a10->fmt.code;
> +	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
> +	ov02a10->fmt = fmt->format;
> +
> +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> +		*v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;

If fmt->which is V4L2_SUBDEV_FORMAT_TRY, the internal driver state must not
be affected. It also should not depend on whether the sensor is streaming
or not. Basically it should be considered a special "candidate" format,
which isn't programmed to the hardware, but just stored aside.

> +
> +	mutex_unlock(&ov02a10->mutex);
> +
> +	return 0;
> +}
[snip]
> +static int ov02a10_power_on(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> +	int ret;
> +
> +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 0);

As we discussed before, the pin names mean their logical function and the
polarity means the function is active. In this case, we want to _activate_
the _reset_ so it should be 1.

> +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 0);

I believe we don't want to deactivate the powerdown yet. First the clock
and regulator need to be enabled.

> +
> +	ret = clk_prepare_enable(ov02a10->eclk);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to enable eclk\n");
> +		return ret;
> +	}
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ov02a10_supply_names),
> +				    ov02a10->supplies);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to enable regulators\n");
> +		goto disable_clk;
> +	}
> +	usleep_range(5000, 6000);
> +
> +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);

Here we want to *deactivate* the powerdown, so the value should be 0.

> +	usleep_range(5000, 6000);
> +
> +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 1);

And here we want to *deactivate* the reset so it should be 0.

> +	usleep_range(5000, 6000);
> +
> +	ret = ov02a10_check_sensor_id(ov02a10);
> +	if (ret)
> +		goto disable_regulator;
> +
> +	return 0;
> +
> +disable_regulator:
> +	regulator_bulk_disable(ARRAY_SIZE(ov02a10_supply_names),
> +			       ov02a10->supplies);
> +disable_clk:
> +	clk_disable_unprepare(ov02a10->eclk);
> +
> +	return ret;
> +}
> +
> +static int ov02a10_power_off(struct device *dev)
> +{
> +	struct i2c_client *client = to_i2c_client(dev);
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> +
> +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 0);

We want to *activate* reset here, so it should be 1.

> +	clk_disable_unprepare(ov02a10->eclk);
> +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 0);

We want to *activate* powerdown here, so should be 1 too.

> +	regulator_bulk_disable(ARRAY_SIZE(ov02a10_supply_names),
> +			       ov02a10->supplies);
> +
> +	return 0;
> +}
[snip]
> +static int ov02a10_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct ov02a10 *ov02a10;
> +	unsigned int rotation;
> +	unsigned int clock_lane_tx_speed;
> +	unsigned int i;
> +	int ret;
> +
> +	ov02a10 = devm_kzalloc(dev, sizeof(*ov02a10), GFP_KERNEL);
> +	if (!ov02a10)
> +		return -ENOMEM;
> +
> +	ret = ov02a10_check_hwcfg(dev, ov02a10);
> +	if (ret) {
> +		dev_err(dev, "failed to check HW configuration: %d", ret);
> +		return ret;
> +	}
> +
> +	v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> +	ov02a10->mipi_clock_tx_speed = OV02A10_MIPI_TX_SPEED_DEFAULT;
> +	ov02a10->fmt.code = MEDIA_BUS_FMT_SBGGR10_1X10;
> +
> +	/* Optional indication of physical rotation of sensor */
> +	ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> +	if (!ret && rotation == 180) {
> +		ov02a10->upside_down = true;
> +		ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> +	}
> +
> +	/* Optional indication of mipi TX speed */
> +	ret = fwnode_property_read_u32(dev_fwnode(dev), "ovti,mipi-tx-speed",
> +				       &clock_lane_tx_speed);
> +
> +	if (!ret)
> +		ov02a10->mipi_clock_tx_speed = clock_lane_tx_speed;
> +
> +	/* Get system clock (eclk) */
> +	ov02a10->eclk = devm_clk_get(dev, "eclk");
> +	if (IS_ERR(ov02a10->eclk)) {
> +		ret = PTR_ERR(ov02a10->eclk);
> +		dev_err(dev, "failed to get eclk %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> +				       &ov02a10->eclk_freq);
> +	if (ret) {
> +		dev_err(dev, "failed to get eclk frequency\n");
> +		return ret;
> +	}
> +
> +	ret = clk_set_rate(ov02a10->eclk, ov02a10->eclk_freq);
> +	if (ret) {
> +		dev_err(dev, "failed to set eclk frequency (24MHz)\n");
> +		return ret;
> +	}
> +
> +	if (clk_get_rate(ov02a10->eclk) != OV02A10_ECLK_FREQ) {
> +		dev_warn(dev, "wrong eclk frequency %d Hz, expected: %d Hz\n",
> +			 ov02a10->eclk_freq, OV02A10_ECLK_FREQ);
> +		return -EINVAL;
> +	}
> +
> +	ov02a10->pd_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_HIGH);
> +	if (IS_ERR(ov02a10->pd_gpio)) {
> +		ret = PTR_ERR(ov02a10->pd_gpio);
> +		dev_err(dev, "failed to get powerdown-gpios %d\n", ret);
> +		return ret;
> +	}
> +
> +	ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ov02a10->rst_gpio)) {
> +		ret = PTR_ERR(ov02a10->rst_gpio);
> +		dev_err(dev, "failed to get reset-gpios %d\n", ret);
> +		return ret;
> +	}
> +
> +	for (i = 0; i < ARRAY_SIZE(ov02a10_supply_names); i++)
> +		ov02a10->supplies[i].supply = ov02a10_supply_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov02a10_supply_names),
> +				      ov02a10->supplies);
> +	if (ret) {
> +		dev_err(dev, "failed to get regulators\n");
> +		return ret;
> +	}
> +
> +	mutex_init(&ov02a10->mutex);
> +	ov02a10->cur_mode = &supported_modes[0];
> +	ret = ov02a10_initialize_controls(ov02a10);
> +	if (ret) {
> +		dev_err(dev, "failed to initialize controls\n");
> +		goto err_destroy_mutex;
> +	}
> +
> +	ov02a10->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	ov02a10->subdev.entity.ops = &ov02a10_subdev_entity_ops;
> +	ov02a10->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> +	ov02a10->pad.flags = MEDIA_PAD_FL_SOURCE;
> +	ret = media_entity_pads_init(&ov02a10->subdev.entity, 1, &ov02a10->pad);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to init entity pads: %d", ret);
> +		goto err_free_handler;
> +	}
> +
> +	pm_runtime_enable(dev);
> +	if (!pm_runtime_enabled(dev)) {
> +		ret = ov02a10_power_on(dev);
> +		if (ret < 0) {
> +			dev_err(dev, "failed to power on: %d\n", ret);
> +			goto err_clean_entity;
> +		}
> +	}
> +
> +	ret = v4l2_async_register_subdev(&ov02a10->subdev);
> +	if (ret) {
> +		dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> +		goto err_power_off;
> +	}
> +
> +	return 0;
> +
> +err_power_off:
> +	pm_runtime_disable(dev);
> +	if (!pm_runtime_enabled(dev))

This would be always true, resulting in unbalanced power off. Moving
pm_runtime_disable() after this if should work better.

> +		ov02a10_power_off(dev);
> +err_clean_entity:
> +	media_entity_cleanup(&ov02a10->subdev.entity);
> +err_free_handler:
> +	v4l2_ctrl_handler_free(ov02a10->subdev.ctrl_handler);
> +err_destroy_mutex:
> +	mutex_destroy(&ov02a10->mutex);
> +
> +	return ret;
> +}
> +
> +static int ov02a10_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> +
> +	v4l2_async_unregister_subdev(sd);
> +	media_entity_cleanup(&sd->entity);
> +	v4l2_ctrl_handler_free(sd->ctrl_handler);
> +	pm_runtime_disable(&client->dev);
> +	if (!pm_runtime_suspended(&client->dev))

Sorry, similarly to the dw9768 driver, I made a mistake and suggested the
wrong function. pm_runtime_status_suspended() should be correct here.

Best regards,
Tomasz

Dongchun Zhu June 20, 2020, 7:48 a.m. UTC | #2

Hi Tomasz,

Thanks for the review.

On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> Hi Dongchun,
> 
> On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > 
> > Signed-off-by: Dongchun Zhu <[e-mail]>
> > ---
> >  MAINTAINERS                 |    1 +
> >  drivers/media/i2c/Kconfig   |   13 +
> >  drivers/media/i2c/Makefile  |    1 +
> >  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 1057 insertions(+)
> >  create mode 100644 drivers/media/i2c/ov02a10.c
> > 
> 
> Thank you for the patch. Please see my comments inline.
> 
> [snip]
> > +static int ov02a10_set_fmt(struct v4l2_subdev *sd,
> > +			   struct v4l2_subdev_pad_config *cfg,
> > +			   struct v4l2_subdev_format *fmt)
> > +{
> > +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > +	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> > +
> > +	mutex_lock(&ov02a10->mutex);
> > +
> > +	if (ov02a10->streaming) {
> > +		mutex_unlock(&ov02a10->mutex);
> > +		return -EBUSY;
> > +	}
> > +
> > +	/* Only one sensor mode supported */
> > +	mbus_fmt->code = ov02a10->fmt.code;
> > +	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
> > +	ov02a10->fmt = fmt->format;
> > +
> > +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > +		*v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
> 
> If fmt->which is V4L2_SUBDEV_FORMAT_TRY, the internal driver state must not
> be affected. It also should not depend on whether the sensor is streaming
> or not. Basically it should be considered a special "candidate" format,
> which isn't programmed to the hardware, but just stored aside.
> 

Hmm. Maybe we shall use FORMAT_TRY like this:
struct v4l2_mbus_framefmt *frame_fmt;
...
if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
	frame_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
else
	frame_fmt = &ov02a10->fmt;

*frame_fmt = *mbus_fmt;

(Remove 'ov02a10->fmt = fmt->format;' above)

> > +
> > +	mutex_unlock(&ov02a10->mutex);
> > +
> > +	return 0;
> > +}
> [snip]
> > +static int ov02a10_power_on(struct device *dev)
> > +{
> > +	struct i2c_client *client = to_i2c_client(dev);
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > +	int ret;
> > +
> > +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 0);
> 
> As we discussed before, the pin names mean their logical function and the
> polarity means the function is active. In this case, we want to _activate_
> the _reset_ so it should be 1.
> 

Yes, you are right.
Sorry that made a mistake about powerdown/reset GPIO polarity settings.
For instance, _reset_ pin shall be active low, not active high.
The following state setting need to update as well.

> > +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 0);
> 
> I believe we don't want to deactivate the powerdown yet. First the clock
> and regulator need to be enabled.
> 

Fixed in next release.

> > +
> > +	ret = clk_prepare_enable(ov02a10->eclk);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to enable eclk\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = regulator_bulk_enable(ARRAY_SIZE(ov02a10_supply_names),
> > +				    ov02a10->supplies);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to enable regulators\n");
> > +		goto disable_clk;
> > +	}
> > +	usleep_range(5000, 6000);
> > +
> > +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
> 
> Here we want to *deactivate* the powerdown, so the value should be 0.
> 

Fixed in next release.

> > +	usleep_range(5000, 6000);
> > +
> > +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 1);
> 
> And here we want to *deactivate* the reset so it should be 0.
> 

Fixed in next release.

> > +	usleep_range(5000, 6000);
> > +
> > +	ret = ov02a10_check_sensor_id(ov02a10);
> > +	if (ret)
> > +		goto disable_regulator;
> > +
> > +	return 0;
> > +
> > +disable_regulator:
> > +	regulator_bulk_disable(ARRAY_SIZE(ov02a10_supply_names),
> > +			       ov02a10->supplies);
> > +disable_clk:
> > +	clk_disable_unprepare(ov02a10->eclk);
> > +
> > +	return ret;
> > +}
> > +
> > +static int ov02a10_power_off(struct device *dev)
> > +{
> > +	struct i2c_client *client = to_i2c_client(dev);
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > +
> > +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 0);
> 
> We want to *activate* reset here, so it should be 1.
> 

Fixed in next release.

> > +	clk_disable_unprepare(ov02a10->eclk);
> > +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 0);
> 
> We want to *activate* powerdown here, so should be 1 too.
> 

Fixed in next release.

> > +	regulator_bulk_disable(ARRAY_SIZE(ov02a10_supply_names),
> > +			       ov02a10->supplies);
> > +
> > +	return 0;
> > +}
> [snip]
> > +static int ov02a10_probe(struct i2c_client *client)
> > +{
> > +	struct device *dev = &client->dev;
> > +	struct ov02a10 *ov02a10;
> > +	unsigned int rotation;
> > +	unsigned int clock_lane_tx_speed;
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	ov02a10 = devm_kzalloc(dev, sizeof(*ov02a10), GFP_KERNEL);
> > +	if (!ov02a10)
> > +		return -ENOMEM;
> > +
> > +	ret = ov02a10_check_hwcfg(dev, ov02a10);
> > +	if (ret) {
> > +		dev_err(dev, "failed to check HW configuration: %d", ret);
> > +		return ret;
> > +	}
> > +
> > +	v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> > +	ov02a10->mipi_clock_tx_speed = OV02A10_MIPI_TX_SPEED_DEFAULT;
> > +	ov02a10->fmt.code = MEDIA_BUS_FMT_SBGGR10_1X10;
> > +
> > +	/* Optional indication of physical rotation of sensor */
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> > +	if (!ret && rotation == 180) {
> > +		ov02a10->upside_down = true;
> > +		ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> > +	}
> > +
> > +	/* Optional indication of mipi TX speed */
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "ovti,mipi-tx-speed",
> > +				       &clock_lane_tx_speed);
> > +
> > +	if (!ret)
> > +		ov02a10->mipi_clock_tx_speed = clock_lane_tx_speed;
> > +
> > +	/* Get system clock (eclk) */
> > +	ov02a10->eclk = devm_clk_get(dev, "eclk");
> > +	if (IS_ERR(ov02a10->eclk)) {
> > +		ret = PTR_ERR(ov02a10->eclk);
> > +		dev_err(dev, "failed to get eclk %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> > +				       &ov02a10->eclk_freq);
> > +	if (ret) {
> > +		dev_err(dev, "failed to get eclk frequency\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = clk_set_rate(ov02a10->eclk, ov02a10->eclk_freq);
> > +	if (ret) {
> > +		dev_err(dev, "failed to set eclk frequency (24MHz)\n");
> > +		return ret;
> > +	}
> > +
> > +	if (clk_get_rate(ov02a10->eclk) != OV02A10_ECLK_FREQ) {
> > +		dev_warn(dev, "wrong eclk frequency %d Hz, expected: %d Hz\n",
> > +			 ov02a10->eclk_freq, OV02A10_ECLK_FREQ);
> > +		return -EINVAL;
> > +	}
> > +
> > +	ov02a10->pd_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_HIGH);
> > +	if (IS_ERR(ov02a10->pd_gpio)) {
> > +		ret = PTR_ERR(ov02a10->pd_gpio);
> > +		dev_err(dev, "failed to get powerdown-gpios %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > +	if (IS_ERR(ov02a10->rst_gpio)) {
> > +		ret = PTR_ERR(ov02a10->rst_gpio);
> > +		dev_err(dev, "failed to get reset-gpios %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	for (i = 0; i < ARRAY_SIZE(ov02a10_supply_names); i++)
> > +		ov02a10->supplies[i].supply = ov02a10_supply_names[i];
> > +
> > +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov02a10_supply_names),
> > +				      ov02a10->supplies);
> > +	if (ret) {
> > +		dev_err(dev, "failed to get regulators\n");
> > +		return ret;
> > +	}
> > +
> > +	mutex_init(&ov02a10->mutex);
> > +	ov02a10->cur_mode = &supported_modes[0];
> > +	ret = ov02a10_initialize_controls(ov02a10);
> > +	if (ret) {
> > +		dev_err(dev, "failed to initialize controls\n");
> > +		goto err_destroy_mutex;
> > +	}
> > +
> > +	ov02a10->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	ov02a10->subdev.entity.ops = &ov02a10_subdev_entity_ops;
> > +	ov02a10->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > +	ov02a10->pad.flags = MEDIA_PAD_FL_SOURCE;
> > +	ret = media_entity_pads_init(&ov02a10->subdev.entity, 1, &ov02a10->pad);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to init entity pads: %d", ret);
> > +		goto err_free_handler;
> > +	}
> > +
> > +	pm_runtime_enable(dev);
> > +	if (!pm_runtime_enabled(dev)) {
> > +		ret = ov02a10_power_on(dev);
> > +		if (ret < 0) {
> > +			dev_err(dev, "failed to power on: %d\n", ret);
> > +			goto err_clean_entity;
> > +		}
> > +	}
> > +
> > +	ret = v4l2_async_register_subdev(&ov02a10->subdev);
> > +	if (ret) {
> > +		dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> > +		goto err_power_off;
> > +	}
> > +
> > +	return 0;
> > +
> > +err_power_off:
> > +	pm_runtime_disable(dev);
> > +	if (!pm_runtime_enabled(dev))
> 
> This would be always true, resulting in unbalanced power off. Moving
> pm_runtime_disable() after this if should work better.
> 

Yes. Fixed in next release.

> > +		ov02a10_power_off(dev);
> > +err_clean_entity:
> > +	media_entity_cleanup(&ov02a10->subdev.entity);
> > +err_free_handler:
> > +	v4l2_ctrl_handler_free(ov02a10->subdev.ctrl_handler);
> > +err_destroy_mutex:
> > +	mutex_destroy(&ov02a10->mutex);
> > +
> > +	return ret;
> > +}
> > +
> > +static int ov02a10_remove(struct i2c_client *client)
> > +{
> > +	struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > +
> > +	v4l2_async_unregister_subdev(sd);
> > +	media_entity_cleanup(&sd->entity);
> > +	v4l2_ctrl_handler_free(sd->ctrl_handler);
> > +	pm_runtime_disable(&client->dev);
> > +	if (!pm_runtime_suspended(&client->dev))
> 
> Sorry, similarly to the dw9768 driver, I made a mistake and suggested the
> wrong function. pm_runtime_status_suspended() should be correct here.
> 

That's OK.
Fixed in next release.

> Best regards,
> Tomasz

Tomasz Figa June 22, 2020, 3:23 p.m. UTC | #3

On Sat, Jun 20, 2020 at 03:48:04PM +0800, Dongchun Zhu wrote:
> Hi Tomasz,
> 
> Thanks for the review.
> 
> On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> > Hi Dongchun,
> > 
> > On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > > 
> > > Signed-off-by: Dongchun Zhu <[e-mail]>
> > > ---
> > >  MAINTAINERS                 |    1 +
> > >  drivers/media/i2c/Kconfig   |   13 +
> > >  drivers/media/i2c/Makefile  |    1 +
> > >  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> > >  4 files changed, 1057 insertions(+)
> > >  create mode 100644 drivers/media/i2c/ov02a10.c
> > > 
> > 
> > Thank you for the patch. Please see my comments inline.
> > 
> > [snip]
> > > +static int ov02a10_set_fmt(struct v4l2_subdev *sd,
> > > +			   struct v4l2_subdev_pad_config *cfg,
> > > +			   struct v4l2_subdev_format *fmt)
> > > +{
> > > +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > > +	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> > > +
> > > +	mutex_lock(&ov02a10->mutex);
> > > +
> > > +	if (ov02a10->streaming) {
> > > +		mutex_unlock(&ov02a10->mutex);
> > > +		return -EBUSY;
> > > +	}
> > > +
> > > +	/* Only one sensor mode supported */
> > > +	mbus_fmt->code = ov02a10->fmt.code;
> > > +	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
> > > +	ov02a10->fmt = fmt->format;
> > > +
> > > +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > > +		*v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
> > 
> > If fmt->which is V4L2_SUBDEV_FORMAT_TRY, the internal driver state must not
> > be affected. It also should not depend on whether the sensor is streaming
> > or not. Basically it should be considered a special "candidate" format,
> > which isn't programmed to the hardware, but just stored aside.
> > 
> 
> Hmm. Maybe we shall use FORMAT_TRY like this:
> struct v4l2_mbus_framefmt *frame_fmt;
> ...
> if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> 	frame_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
> else
> 	frame_fmt = &ov02a10->fmt;
> 
> *frame_fmt = *mbus_fmt;
> 
> (Remove 'ov02a10->fmt = fmt->format;' above)
>

Yes, I guess that should work. Also the ov02a10->streaming condition
shouldn't be checked if fmt->which is V4L2_SUBDEV_FORMAT_TRY).

Best regards,
Tomasz

Dongchun Zhu June 29, 2020, 6:30 a.m. UTC | #4

Hi Tomasz,

Thanks for the review.

On Mon, 2020-06-22 at 15:23 +0000, Tomasz Figa wrote:
> On Sat, Jun 20, 2020 at 03:48:04PM +0800, Dongchun Zhu wrote:
> > Hi Tomasz,
> > 
> > Thanks for the review.
> > 
> > On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> > > Hi Dongchun,
> > > 
> > > On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > > > 
> > > > Signed-off-by: Dongchun Zhu <[e-mail]>
> > > > ---
> > > >  MAINTAINERS                 |    1 +
> > > >  drivers/media/i2c/Kconfig   |   13 +
> > > >  drivers/media/i2c/Makefile  |    1 +
> > > >  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> > > >  4 files changed, 1057 insertions(+)
> > > >  create mode 100644 drivers/media/i2c/ov02a10.c
> > > > 
> > > 
> > > Thank you for the patch. Please see my comments inline.
> > > 
> > > [snip]
> > > > +static int ov02a10_set_fmt(struct v4l2_subdev *sd,
> > > > +			   struct v4l2_subdev_pad_config *cfg,
> > > > +			   struct v4l2_subdev_format *fmt)
> > > > +{
> > > > +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > > > +	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> > > > +
> > > > +	mutex_lock(&ov02a10->mutex);
> > > > +
> > > > +	if (ov02a10->streaming) {
> > > > +		mutex_unlock(&ov02a10->mutex);
> > > > +		return -EBUSY;
> > > > +	}
> > > > +
> > > > +	/* Only one sensor mode supported */
> > > > +	mbus_fmt->code = ov02a10->fmt.code;
> > > > +	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
> > > > +	ov02a10->fmt = fmt->format;
> > > > +
> > > > +	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > > > +		*v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
> > > 
> > > If fmt->which is V4L2_SUBDEV_FORMAT_TRY, the internal driver state must not
> > > be affected. It also should not depend on whether the sensor is streaming
> > > or not. Basically it should be considered a special "candidate" format,
> > > which isn't programmed to the hardware, but just stored aside.
> > > 
> > 
> > Hmm. Maybe we shall use FORMAT_TRY like this:
> > struct v4l2_mbus_framefmt *frame_fmt;
> > ...
> > if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > 	frame_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
> > else
> > 	frame_fmt = &ov02a10->fmt;
> > 
> > *frame_fmt = *mbus_fmt;
> > 
> > (Remove 'ov02a10->fmt = fmt->format;' above)
> >
> 
> Yes, I guess that should work. Also the ov02a10->streaming condition
> shouldn't be checked if fmt->which is V4L2_SUBDEV_FORMAT_TRY).
> 

Maybe we shall use more strict condition to check streaming state:
'if (ov02a10->streaming)' --> 'if (ov02a10->streaming && fmt->which ==
V4L2_SUBDEV_FORMAT_ACTIVE)'

> Best regards,
> Tomasz

Dongchun Zhu June 29, 2020, 7:53 a.m. UTC | #5

Hi Tomasz,

On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> Hi Dongchun,
> 
> On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > 
> > Signed-off-by: Dongchun Zhu <[e-mail]>
> > ---
> >  MAINTAINERS                 |    1 +
> >  drivers/media/i2c/Kconfig   |   13 +
> >  drivers/media/i2c/Makefile  |    1 +
> >  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 1057 insertions(+)
> >  create mode 100644 drivers/media/i2c/ov02a10.c
> > 
> 
> Thank you for the patch. Please see my comments inline.
> 

[snip]

> > +static int ov02a10_probe(struct i2c_client *client)
> > +{
> > +	struct device *dev = &client->dev;
> > +	struct ov02a10 *ov02a10;
> > +	unsigned int rotation;
> > +	unsigned int clock_lane_tx_speed;
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	ov02a10 = devm_kzalloc(dev, sizeof(*ov02a10), GFP_KERNEL);
> > +	if (!ov02a10)
> > +		return -ENOMEM;
> > +
> > +	ret = ov02a10_check_hwcfg(dev, ov02a10);
> > +	if (ret) {
> > +		dev_err(dev, "failed to check HW configuration: %d", ret);
> > +		return ret;
> > +	}
> > +
> > +	v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> > +	ov02a10->mipi_clock_tx_speed = OV02A10_MIPI_TX_SPEED_DEFAULT;
> > +	ov02a10->fmt.code = MEDIA_BUS_FMT_SBGGR10_1X10;
> > +
> > +	/* Optional indication of physical rotation of sensor */
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> > +	if (!ret && rotation == 180) {
> > +		ov02a10->upside_down = true;
> > +		ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> > +	}
> > +
> > +	/* Optional indication of mipi TX speed */
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "ovti,mipi-tx-speed",
> > +				       &clock_lane_tx_speed);
> > +
> > +	if (!ret)
> > +		ov02a10->mipi_clock_tx_speed = clock_lane_tx_speed;
> > +
> > +	/* Get system clock (eclk) */
> > +	ov02a10->eclk = devm_clk_get(dev, "eclk");
> > +	if (IS_ERR(ov02a10->eclk)) {
> > +		ret = PTR_ERR(ov02a10->eclk);
> > +		dev_err(dev, "failed to get eclk %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> > +				       &ov02a10->eclk_freq);
> > +	if (ret) {
> > +		dev_err(dev, "failed to get eclk frequency\n");
> > +		return ret;
> > +	}
> > +
> > +	ret = clk_set_rate(ov02a10->eclk, ov02a10->eclk_freq);
> > +	if (ret) {
> > +		dev_err(dev, "failed to set eclk frequency (24MHz)\n");
> > +		return ret;
> > +	}
> > +
> > +	if (clk_get_rate(ov02a10->eclk) != OV02A10_ECLK_FREQ) {
> > +		dev_warn(dev, "wrong eclk frequency %d Hz, expected: %d Hz\n",
> > +			 ov02a10->eclk_freq, OV02A10_ECLK_FREQ);
> > +		return -EINVAL;
> > +	}
> > +
> > +	ov02a10->pd_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_HIGH);
> > +	if (IS_ERR(ov02a10->pd_gpio)) {
> > +		ret = PTR_ERR(ov02a10->pd_gpio);
> > +		dev_err(dev, "failed to get powerdown-gpios %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > +	if (IS_ERR(ov02a10->rst_gpio)) {
> > +		ret = PTR_ERR(ov02a10->rst_gpio);
> > +		dev_err(dev, "failed to get reset-gpios %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	for (i = 0; i < ARRAY_SIZE(ov02a10_supply_names); i++)
> > +		ov02a10->supplies[i].supply = ov02a10_supply_names[i];
> > +
> > +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov02a10_supply_names),
> > +				      ov02a10->supplies);
> > +	if (ret) {
> > +		dev_err(dev, "failed to get regulators\n");
> > +		return ret;
> > +	}
> > +
> > +	mutex_init(&ov02a10->mutex);
> > +	ov02a10->cur_mode = &supported_modes[0];
> > +	ret = ov02a10_initialize_controls(ov02a10);
> > +	if (ret) {
> > +		dev_err(dev, "failed to initialize controls\n");
> > +		goto err_destroy_mutex;
> > +	}
> > +
> > +	ov02a10->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > +	ov02a10->subdev.entity.ops = &ov02a10_subdev_entity_ops;
> > +	ov02a10->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > +	ov02a10->pad.flags = MEDIA_PAD_FL_SOURCE;
> > +	ret = media_entity_pads_init(&ov02a10->subdev.entity, 1, &ov02a10->pad);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to init entity pads: %d", ret);
> > +		goto err_free_handler;
> > +	}
> > +
> > +	pm_runtime_enable(dev);
> > +	if (!pm_runtime_enabled(dev)) {
> > +		ret = ov02a10_power_on(dev);
> > +		if (ret < 0) {
> > +			dev_err(dev, "failed to power on: %d\n", ret);
> > +			goto err_clean_entity;
> > +		}
> > +	}
> > +
> > +	ret = v4l2_async_register_subdev(&ov02a10->subdev);
> > +	if (ret) {
> > +		dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> > +		goto err_power_off;
> > +	}
> > +
> > +	return 0;
> > +
> > +err_power_off:
> > +	pm_runtime_disable(dev);
> > +	if (!pm_runtime_enabled(dev))
> 
> This would be always true, resulting in unbalanced power off. Moving
> pm_runtime_disable() after this if should work better.
> 

Pardon, do you mean that we shall use like this:
err_power_off:
	if (!pm_runtime_enabled(dev)) {
		pm_runtime_disable(dev);
		if (!pm_runtime_status_suspended(dev)
			ov02a10_power_off(dev);
	}

> > +		ov02a10_power_off(dev);
> > +err_clean_entity:
> > +	media_entity_cleanup(&ov02a10->subdev.entity);
> > +err_free_handler:
> > +	v4l2_ctrl_handler_free(ov02a10->subdev.ctrl_handler);
> > +err_destroy_mutex:
> > +	mutex_destroy(&ov02a10->mutex);
> > +
> > +	return ret;
> > +}
> > +

[snip]
...

Tomasz Figa June 29, 2020, 10:22 a.m. UTC | #6

On Mon, Jun 29, 2020 at 8:30 AM Dongchun Zhu <[e-mail]> wrote:
>
> Hi Tomasz,
>
> Thanks for the review.
>
> On Mon, 2020-06-22 at 15:23 +0000, Tomasz Figa wrote:
> > On Sat, Jun 20, 2020 at 03:48:04PM +0800, Dongchun Zhu wrote:
> > > Hi Tomasz,
> > >
> > > Thanks for the review.
> > >
> > > On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> > > > Hi Dongchun,
> > > >
> > > > On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > > > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > > > >
> > > > > Signed-off-by: Dongchun Zhu <[e-mail]>
> > > > > ---
> > > > >  MAINTAINERS                 |    1 +
> > > > >  drivers/media/i2c/Kconfig   |   13 +
> > > > >  drivers/media/i2c/Makefile  |    1 +
> > > > >  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> > > > >  4 files changed, 1057 insertions(+)
> > > > >  create mode 100644 drivers/media/i2c/ov02a10.c
> > > > >
> > > >
> > > > Thank you for the patch. Please see my comments inline.
> > > >
> > > > [snip]
> > > > > +static int ov02a10_set_fmt(struct v4l2_subdev *sd,
> > > > > +                          struct v4l2_subdev_pad_config *cfg,
> > > > > +                          struct v4l2_subdev_format *fmt)
> > > > > +{
> > > > > +       struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > > > > +       struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
> > > > > +
> > > > > +       mutex_lock(&ov02a10->mutex);
> > > > > +
> > > > > +       if (ov02a10->streaming) {
> > > > > +               mutex_unlock(&ov02a10->mutex);
> > > > > +               return -EBUSY;
> > > > > +       }
> > > > > +
> > > > > +       /* Only one sensor mode supported */
> > > > > +       mbus_fmt->code = ov02a10->fmt.code;
> > > > > +       ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
> > > > > +       ov02a10->fmt = fmt->format;
> > > > > +
> > > > > +       if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > > > > +               *v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
> > > >
> > > > If fmt->which is V4L2_SUBDEV_FORMAT_TRY, the internal driver state must not
> > > > be affected. It also should not depend on whether the sensor is streaming
> > > > or not. Basically it should be considered a special "candidate" format,
> > > > which isn't programmed to the hardware, but just stored aside.
> > > >
> > >
> > > Hmm. Maybe we shall use FORMAT_TRY like this:
> > > struct v4l2_mbus_framefmt *frame_fmt;
> > > ...
> > > if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
> > >     frame_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
> > > else
> > >     frame_fmt = &ov02a10->fmt;
> > >
> > > *frame_fmt = *mbus_fmt;
> > >
> > > (Remove 'ov02a10->fmt = fmt->format;' above)
> > >
> >
> > Yes, I guess that should work. Also the ov02a10->streaming condition
> > shouldn't be checked if fmt->which is V4L2_SUBDEV_FORMAT_TRY).
> >
>
> Maybe we shall use more strict condition to check streaming state:
> 'if (ov02a10->streaming)' --> 'if (ov02a10->streaming && fmt->which ==
> V4L2_SUBDEV_FORMAT_ACTIVE)'

Yes, that should work.

Best regards,
Tomasz

Tomasz Figa June 29, 2020, 10:27 a.m. UTC | #7

On Mon, Jun 29, 2020 at 9:54 AM Dongchun Zhu <[e-mail]> wrote:
>
> Hi Tomasz,
>
> On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> > Hi Dongchun,
> >
> > On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > >
> > > Signed-off-by: Dongchun Zhu <[e-mail]>
> > > ---
> > >  MAINTAINERS                 |    1 +
> > >  drivers/media/i2c/Kconfig   |   13 +
> > >  drivers/media/i2c/Makefile  |    1 +
> > >  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> > >  4 files changed, 1057 insertions(+)
> > >  create mode 100644 drivers/media/i2c/ov02a10.c
> > >
> >
> > Thank you for the patch. Please see my comments inline.
> >
>
> [snip]
>
> > > +static int ov02a10_probe(struct i2c_client *client)
> > > +{
> > > +   struct device *dev = &client->dev;
> > > +   struct ov02a10 *ov02a10;
> > > +   unsigned int rotation;
> > > +   unsigned int clock_lane_tx_speed;
> > > +   unsigned int i;
> > > +   int ret;
> > > +
> > > +   ov02a10 = devm_kzalloc(dev, sizeof(*ov02a10), GFP_KERNEL);
> > > +   if (!ov02a10)
> > > +           return -ENOMEM;
> > > +
> > > +   ret = ov02a10_check_hwcfg(dev, ov02a10);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to check HW configuration: %d", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> > > +   ov02a10->mipi_clock_tx_speed = OV02A10_MIPI_TX_SPEED_DEFAULT;
> > > +   ov02a10->fmt.code = MEDIA_BUS_FMT_SBGGR10_1X10;
> > > +
> > > +   /* Optional indication of physical rotation of sensor */
> > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> > > +   if (!ret && rotation == 180) {
> > > +           ov02a10->upside_down = true;
> > > +           ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> > > +   }
> > > +
> > > +   /* Optional indication of mipi TX speed */
> > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "ovti,mipi-tx-speed",
> > > +                                  &clock_lane_tx_speed);
> > > +
> > > +   if (!ret)
> > > +           ov02a10->mipi_clock_tx_speed = clock_lane_tx_speed;
> > > +
> > > +   /* Get system clock (eclk) */
> > > +   ov02a10->eclk = devm_clk_get(dev, "eclk");
> > > +   if (IS_ERR(ov02a10->eclk)) {
> > > +           ret = PTR_ERR(ov02a10->eclk);
> > > +           dev_err(dev, "failed to get eclk %d\n", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> > > +                                  &ov02a10->eclk_freq);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to get eclk frequency\n");
> > > +           return ret;
> > > +   }
> > > +
> > > +   ret = clk_set_rate(ov02a10->eclk, ov02a10->eclk_freq);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to set eclk frequency (24MHz)\n");
> > > +           return ret;
> > > +   }
> > > +
> > > +   if (clk_get_rate(ov02a10->eclk) != OV02A10_ECLK_FREQ) {
> > > +           dev_warn(dev, "wrong eclk frequency %d Hz, expected: %d Hz\n",
> > > +                    ov02a10->eclk_freq, OV02A10_ECLK_FREQ);
> > > +           return -EINVAL;
> > > +   }
> > > +
> > > +   ov02a10->pd_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_HIGH);
> > > +   if (IS_ERR(ov02a10->pd_gpio)) {
> > > +           ret = PTR_ERR(ov02a10->pd_gpio);
> > > +           dev_err(dev, "failed to get powerdown-gpios %d\n", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > > +   if (IS_ERR(ov02a10->rst_gpio)) {
> > > +           ret = PTR_ERR(ov02a10->rst_gpio);
> > > +           dev_err(dev, "failed to get reset-gpios %d\n", ret);
> > > +           return ret;
> > > +   }
> > > +
> > > +   for (i = 0; i < ARRAY_SIZE(ov02a10_supply_names); i++)
> > > +           ov02a10->supplies[i].supply = ov02a10_supply_names[i];
> > > +
> > > +   ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov02a10_supply_names),
> > > +                                 ov02a10->supplies);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to get regulators\n");
> > > +           return ret;
> > > +   }
> > > +
> > > +   mutex_init(&ov02a10->mutex);
> > > +   ov02a10->cur_mode = &supported_modes[0];
> > > +   ret = ov02a10_initialize_controls(ov02a10);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to initialize controls\n");
> > > +           goto err_destroy_mutex;
> > > +   }
> > > +
> > > +   ov02a10->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > > +   ov02a10->subdev.entity.ops = &ov02a10_subdev_entity_ops;
> > > +   ov02a10->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > > +   ov02a10->pad.flags = MEDIA_PAD_FL_SOURCE;
> > > +   ret = media_entity_pads_init(&ov02a10->subdev.entity, 1, &ov02a10->pad);
> > > +   if (ret < 0) {
> > > +           dev_err(dev, "failed to init entity pads: %d", ret);
> > > +           goto err_free_handler;
> > > +   }
> > > +
> > > +   pm_runtime_enable(dev);
> > > +   if (!pm_runtime_enabled(dev)) {
> > > +           ret = ov02a10_power_on(dev);
> > > +           if (ret < 0) {
> > > +                   dev_err(dev, "failed to power on: %d\n", ret);
> > > +                   goto err_clean_entity;
> > > +           }
> > > +   }
> > > +
> > > +   ret = v4l2_async_register_subdev(&ov02a10->subdev);
> > > +   if (ret) {
> > > +           dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> > > +           goto err_power_off;
> > > +   }
> > > +
> > > +   return 0;
> > > +
> > > +err_power_off:
> > > +   pm_runtime_disable(dev);
> > > +   if (!pm_runtime_enabled(dev))
> >
> > This would be always true, resulting in unbalanced power off. Moving
> > pm_runtime_disable() after this if should work better.
> >
>
> Pardon, do you mean that we shall use like this:
> err_power_off:
>         if (!pm_runtime_enabled(dev)) {
>                 pm_runtime_disable(dev);
>                 if (!pm_runtime_status_suspended(dev)
>                         ov02a10_power_off(dev);
>         }

Hmm, that wouldn't really work, because there is no reason to disable
runtime PM if it's disabled already. I also noticed that we don't need
to check pm_runtime_status_suspended() in the error path in probe,
because we only ever attempt to power it on when runtime PM is
disabled in kernel config. This would make the end result as:

         if (pm_runtime_enabled(dev))
                 pm_runtime_disable(dev);
         else
                 ov02a10_power_off(dev);

Best regards,
Tomasz

Dongchun Zhu June 30, 2020, 1:13 a.m. UTC | #8

Hi Tomasz,

On Mon, 2020-06-29 at 12:27 +0200, Tomasz Figa wrote:
> On Mon, Jun 29, 2020 at 9:54 AM Dongchun Zhu <[e-mail]> wrote:
> >
> > Hi Tomasz,
> >
> > On Thu, 2020-06-18 at 19:10 +0000, Tomasz Figa wrote:
> > > Hi Dongchun,
> > >
> > > On Mon, Jun 15, 2020 at 08:29:37PM +0800, Dongchun Zhu wrote:
> > > > Add a V4L2 sub-device driver for OV02A10 image sensor.
> > > >
> > > > Signed-off-by: Dongchun Zhu <[e-mail]>
> > > > ---
> > > >  MAINTAINERS                 |    1 +
> > > >  drivers/media/i2c/Kconfig   |   13 +
> > > >  drivers/media/i2c/Makefile  |    1 +
> > > >  drivers/media/i2c/ov02a10.c | 1042 +++++++++++++++++++++++++++++++++++++++++++
> > > >  4 files changed, 1057 insertions(+)
> > > >  create mode 100644 drivers/media/i2c/ov02a10.c
> > > >
> > >
> > > Thank you for the patch. Please see my comments inline.
> > >
> >
> > [snip]
> >
> > > > +static int ov02a10_probe(struct i2c_client *client)
> > > > +{
> > > > +   struct device *dev = &client->dev;
> > > > +   struct ov02a10 *ov02a10;
> > > > +   unsigned int rotation;
> > > > +   unsigned int clock_lane_tx_speed;
> > > > +   unsigned int i;
> > > > +   int ret;
> > > > +
> > > > +   ov02a10 = devm_kzalloc(dev, sizeof(*ov02a10), GFP_KERNEL);
> > > > +   if (!ov02a10)
> > > > +           return -ENOMEM;
> > > > +
> > > > +   ret = ov02a10_check_hwcfg(dev, ov02a10);
> > > > +   if (ret) {
> > > > +           dev_err(dev, "failed to check HW configuration: %d", ret);
> > > > +           return ret;
> > > > +   }
> > > > +
> > > > +   v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> > > > +   ov02a10->mipi_clock_tx_speed = OV02A10_MIPI_TX_SPEED_DEFAULT;
> > > > +   ov02a10->fmt.code = MEDIA_BUS_FMT_SBGGR10_1X10;
> > > > +
> > > > +   /* Optional indication of physical rotation of sensor */
> > > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> > > > +   if (!ret && rotation == 180) {
> > > > +           ov02a10->upside_down = true;
> > > > +           ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> > > > +   }
> > > > +
> > > > +   /* Optional indication of mipi TX speed */
> > > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "ovti,mipi-tx-speed",
> > > > +                                  &clock_lane_tx_speed);
> > > > +
> > > > +   if (!ret)
> > > > +           ov02a10->mipi_clock_tx_speed = clock_lane_tx_speed;
> > > > +
> > > > +   /* Get system clock (eclk) */
> > > > +   ov02a10->eclk = devm_clk_get(dev, "eclk");
> > > > +   if (IS_ERR(ov02a10->eclk)) {
> > > > +           ret = PTR_ERR(ov02a10->eclk);
> > > > +           dev_err(dev, "failed to get eclk %d\n", ret);
> > > > +           return ret;
> > > > +   }
> > > > +
> > > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> > > > +                                  &ov02a10->eclk_freq);
> > > > +   if (ret) {
> > > > +           dev_err(dev, "failed to get eclk frequency\n");
> > > > +           return ret;
> > > > +   }
> > > > +
> > > > +   ret = clk_set_rate(ov02a10->eclk, ov02a10->eclk_freq);
> > > > +   if (ret) {
> > > > +           dev_err(dev, "failed to set eclk frequency (24MHz)\n");
> > > > +           return ret;
> > > > +   }
> > > > +
> > > > +   if (clk_get_rate(ov02a10->eclk) != OV02A10_ECLK_FREQ) {
> > > > +           dev_warn(dev, "wrong eclk frequency %d Hz, expected: %d Hz\n",
> > > > +                    ov02a10->eclk_freq, OV02A10_ECLK_FREQ);
> > > > +           return -EINVAL;
> > > > +   }
> > > > +
> > > > +   ov02a10->pd_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_HIGH);
> > > > +   if (IS_ERR(ov02a10->pd_gpio)) {
> > > > +           ret = PTR_ERR(ov02a10->pd_gpio);
> > > > +           dev_err(dev, "failed to get powerdown-gpios %d\n", ret);
> > > > +           return ret;
> > > > +   }
> > > > +
> > > > +   ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > > > +   if (IS_ERR(ov02a10->rst_gpio)) {
> > > > +           ret = PTR_ERR(ov02a10->rst_gpio);
> > > > +           dev_err(dev, "failed to get reset-gpios %d\n", ret);
> > > > +           return ret;
> > > > +   }
> > > > +
> > > > +   for (i = 0; i < ARRAY_SIZE(ov02a10_supply_names); i++)
> > > > +           ov02a10->supplies[i].supply = ov02a10_supply_names[i];
> > > > +
> > > > +   ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov02a10_supply_names),
> > > > +                                 ov02a10->supplies);
> > > > +   if (ret) {
> > > > +           dev_err(dev, "failed to get regulators\n");
> > > > +           return ret;
> > > > +   }
> > > > +
> > > > +   mutex_init(&ov02a10->mutex);
> > > > +   ov02a10->cur_mode = &supported_modes[0];
> > > > +   ret = ov02a10_initialize_controls(ov02a10);
> > > > +   if (ret) {
> > > > +           dev_err(dev, "failed to initialize controls\n");
> > > > +           goto err_destroy_mutex;
> > > > +   }
> > > > +
> > > > +   ov02a10->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > > > +   ov02a10->subdev.entity.ops = &ov02a10_subdev_entity_ops;
> > > > +   ov02a10->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > > > +   ov02a10->pad.flags = MEDIA_PAD_FL_SOURCE;
> > > > +   ret = media_entity_pads_init(&ov02a10->subdev.entity, 1, &ov02a10->pad);
> > > > +   if (ret < 0) {
> > > > +           dev_err(dev, "failed to init entity pads: %d", ret);
> > > > +           goto err_free_handler;
> > > > +   }
> > > > +
> > > > +   pm_runtime_enable(dev);
> > > > +   if (!pm_runtime_enabled(dev)) {
> > > > +           ret = ov02a10_power_on(dev);
> > > > +           if (ret < 0) {
> > > > +                   dev_err(dev, "failed to power on: %d\n", ret);
> > > > +                   goto err_clean_entity;
> > > > +           }
> > > > +   }
> > > > +
> > > > +   ret = v4l2_async_register_subdev(&ov02a10->subdev);
> > > > +   if (ret) {
> > > > +           dev_err(dev, "failed to register V4L2 subdev: %d", ret);
> > > > +           goto err_power_off;
> > > > +   }
> > > > +
> > > > +   return 0;
> > > > +
> > > > +err_power_off:
> > > > +   pm_runtime_disable(dev);
> > > > +   if (!pm_runtime_enabled(dev))
> > >
> > > This would be always true, resulting in unbalanced power off. Moving
> > > pm_runtime_disable() after this if should work better.
> > >
> >
> > Pardon, do you mean that we shall use like this:
> > err_power_off:
> >         if (!pm_runtime_enabled(dev)) {
> >                 pm_runtime_disable(dev);
> >                 if (!pm_runtime_status_suspended(dev)
> >                         ov02a10_power_off(dev);
> >         }
> 
> Hmm, that wouldn't really work, because there is no reason to disable
> runtime PM if it's disabled already. I also noticed that we don't need
> to check pm_runtime_status_suspended() in the error path in probe,
> because we only ever attempt to power it on when runtime PM is
> disabled in kernel config. This would make the end result as:
> 
>          if (pm_runtime_enabled(dev))
>                  pm_runtime_disable(dev);
>          else
>                  ov02a10_power_off(dev);
> 

Thanks for the sharing.
It seems err_power_off section here helps balance the pm_runtime_enable
and pm_runtime_disable to keep dev->power.disable_depth right.
While runtime PM is disabled, ov02a10_power_off could also perform power
off instead of runtime PM.

> Best regards,
> Tomasz

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 63a2335..e7677c5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12395,6 +12395,7 @@  L:	[e-mail]
 S:	Maintained
 T:	git git://linuxtv.org/media_tree.git
 F:	Documentation/devicetree/bindings/media/i2c/ovti,ov02a10.yaml
+F:	drivers/media/i2c/ov02a10.c
 
 OMNIVISION OV13858 SENSOR DRIVER
 M:	Sakari Ailus <[e-mail]>
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 125d596..d8572cd 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -655,6 +655,19 @@  config VIDEO_IMX355
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx355.
 
+config VIDEO_OV02A10
+	tristate "OmniVision OV02A10 sensor support"
+	depends on I2C && VIDEO_V4L2
+	select MEDIA_CONTROLLER
+	select VIDEO_V4L2_SUBDEV_API
+	select V4L2_FWNODE
+	help
+	  This is a Video4Linux2 sensor driver for the OmniVision
+	  OV02A10 camera.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ov02a10.
+
 config VIDEO_OV2640
 	tristate "OmniVision OV2640 sensor support"
 	depends on VIDEO_V4L2 && I2C
diff --git a/drivers/media/i2c/Makefile b/drivers/media/i2c/Makefile
index 77bf7d0..6566dd9 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -63,6 +63,7 @@  obj-$(CONFIG_VIDEO_VP27SMPX) += vp27smpx.o
 obj-$(CONFIG_VIDEO_SONY_BTF_MPX) += sony-btf-mpx.o
 obj-$(CONFIG_VIDEO_UPD64031A) += upd64031a.o
 obj-$(CONFIG_VIDEO_UPD64083) += upd64083.o
+obj-$(CONFIG_VIDEO_OV02A10) += ov02a10.o
 obj-$(CONFIG_VIDEO_OV2640) += ov2640.o
 obj-$(CONFIG_VIDEO_OV2680) += ov2680.o
 obj-$(CONFIG_VIDEO_OV2685) += ov2685.o
diff --git a/drivers/media/i2c/ov02a10.c b/drivers/media/i2c/ov02a10.c
new file mode 100644
index 0000000..3160c92
--- /dev/null
+++ b/drivers/media/i2c/ov02a10.c
@@ -0,0 +1,1042 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 MediaTek Inc.
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
+#include <media/media-entity.h>
+#include <media/v4l2-async.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-subdev.h>
+#include <media/v4l2-fwnode.h>
+
+#define CHIP_ID						0x2509
+#define OV02A10_REG_CHIP_ID_H				0x02
+#define OV02A10_REG_CHIP_ID_L				0x03
+
+/* Bit[1] vertical upside down */
+/* Bit[0] horizontal mirror */
+#define REG_MIRROR_FLIP_CONTROL				0x3f
+
+/* Orientation */
+#define REG_MIRROR_FLIP_ENABLE				0x03
+
+/* Bit[2:0] MIPI transmission speed select */
+#define TX_SPEED_AREA_SEL				0xa1
+#define OV02A10_MIPI_TX_SPEED_DEFAULT			0x03
+
+#define REG_PAGE_SWITCH					0xfd
+#define REG_GLOBAL_EFFECTIVE				0x01
+#define REG_ENABLE					BIT(0)
+
+#define REG_SC_CTRL_MODE				0xac
+#define SC_CTRL_MODE_STANDBY				0x00
+#define SC_CTRL_MODE_STREAMING				0x01
+
+#define OV02A10_EXP_SHIFT				8
+#define OV02A10_REG_EXPOSURE_H				0x03
+#define OV02A10_REG_EXPOSURE_L				0x04
+#define	OV02A10_EXPOSURE_MIN				4
+#define OV02A10_EXPOSURE_MAX_MARGIN			4
+#define	OV02A10_EXPOSURE_STEP				1
+
+#define OV02A10_VTS_SHIFT				8
+#define OV02A10_REG_VTS_H				0x05
+#define OV02A10_REG_VTS_L				0x06
+#define OV02A10_VTS_MAX					0x209f
+#define OV02A10_BASIC_LINE				1224
+
+#define OV02A10_REG_GAIN				0x24
+#define OV02A10_GAIN_MIN				0x10
+#define OV02A10_GAIN_MAX				0xf8
+#define OV02A10_GAIN_STEP				0x01
+#define OV02A10_GAIN_DEFAULT				0x40
+
+/* Test pattern control */
+#define OV02A10_REG_TEST_PATTERN			0xb6
+
+#define HZ_PER_MHZ					1000000L
+#define OV02A10_LINK_FREQ_390MHZ			(390 * HZ_PER_MHZ)
+#define OV02A10_ECLK_FREQ				(24 * HZ_PER_MHZ)
+#define OV02A10_DATA_LANES				1
+#define OV02A10_BITS_PER_SAMPLE				10
+
+static const char * const ov02a10_supply_names[] = {
+	"dovdd",	/* Digital I/O power */
+	"avdd",		/* Analog power */
+	"dvdd",		/* Digital core power */
+};
+
+struct ov02a10_reg {
+	u8 addr;
+	u8 val;
+};
+
+struct ov02a10_reg_list {
+	u32 num_of_regs;
+	const struct ov02a10_reg *regs;
+};
+
+struct ov02a10_mode {
+	u32 width;
+	u32 height;
+	u32 exp_def;
+	u32 hts_def;
+	u32 vts_def;
+	const struct ov02a10_reg_list reg_list;
+};
+
+struct ov02a10 {
+	u32 eclk_freq;
+	u32 mipi_clock_tx_speed;
+
+	struct clk *eclk;
+	struct gpio_desc *pd_gpio;
+	struct gpio_desc *rst_gpio;
+	struct regulator_bulk_data supplies[ARRAY_SIZE(ov02a10_supply_names)];
+
+	bool streaming;
+	bool upside_down;
+
+	/*
+	 * Serialize control access, get/set format, get selection
+	 * and start streaming.
+	 */
+	struct mutex mutex;
+	struct v4l2_subdev subdev;
+	struct media_pad pad;
+	struct v4l2_mbus_framefmt fmt;
+	struct v4l2_ctrl_handler ctrl_handler;
+	struct v4l2_ctrl *exposure;
+
+	const struct ov02a10_mode *cur_mode;
+};
+
+static inline struct ov02a10 *to_ov02a10(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct ov02a10, subdev);
+}
+
+/*
+ * eclk 24Mhz
+ * pclk 39Mhz
+ * linelength 934(0x3a6)
+ * framelength 1390(0x56E)
+ * grabwindow_width 1600
+ * grabwindow_height 1200
+ * max_framerate 30fps
+ * mipi_datarate per lane 780Mbps
+ */
+static const struct ov02a10_reg ov02a10_1600x1200_regs[] = {
+	{0xfd, 0x01},
+	{0xac, 0x00},
+	{0xfd, 0x00},
+	{0x2f, 0x29},
+	{0x34, 0x00},
+	{0x35, 0x21},
+	{0x30, 0x15},
+	{0x33, 0x01},
+	{0xfd, 0x01},
+	{0x44, 0x00},
+	{0x2a, 0x4c},
+	{0x2b, 0x1e},
+	{0x2c, 0x60},
+	{0x25, 0x11},
+	{0x03, 0x01},
+	{0x04, 0xae},
+	{0x09, 0x00},
+	{0x0a, 0x02},
+	{0x06, 0xa6},
+	{0x31, 0x00},
+	{0x24, 0x40},
+	{0x01, 0x01},
+	{0xfb, 0x73},
+	{0xfd, 0x01},
+	{0x16, 0x04},
+	{0x1c, 0x09},
+	{0x21, 0x42},
+	{0x12, 0x04},
+	{0x13, 0x10},
+	{0x11, 0x40},
+	{0x33, 0x81},
+	{0xd0, 0x00},
+	{0xd1, 0x01},
+	{0xd2, 0x00},
+	{0x50, 0x10},
+	{0x51, 0x23},
+	{0x52, 0x20},
+	{0x53, 0x10},
+	{0x54, 0x02},
+	{0x55, 0x20},
+	{0x56, 0x02},
+	{0x58, 0x48},
+	{0x5d, 0x15},
+	{0x5e, 0x05},
+	{0x66, 0x66},
+	{0x68, 0x68},
+	{0x6b, 0x00},
+	{0x6c, 0x00},
+	{0x6f, 0x40},
+	{0x70, 0x40},
+	{0x71, 0x0a},
+	{0x72, 0xf0},
+	{0x73, 0x10},
+	{0x75, 0x80},
+	{0x76, 0x10},
+	{0x84, 0x00},
+	{0x85, 0x10},
+	{0x86, 0x10},
+	{0x87, 0x00},
+	{0x8a, 0x22},
+	{0x8b, 0x22},
+	{0x19, 0xf1},
+	{0x29, 0x01},
+	{0xfd, 0x01},
+	{0x9d, 0x16},
+	{0xa0, 0x29},
+	{0xa1, 0x03},
+	{0xad, 0x62},
+	{0xae, 0x00},
+	{0xaf, 0x85},
+	{0xb1, 0x01},
+	{0x8e, 0x06},
+	{0x8f, 0x40},
+	{0x90, 0x04},
+	{0x91, 0xb0},
+	{0x45, 0x01},
+	{0x46, 0x00},
+	{0x47, 0x6c},
+	{0x48, 0x03},
+	{0x49, 0x8b},
+	{0x4a, 0x00},
+	{0x4b, 0x07},
+	{0x4c, 0x04},
+	{0x4d, 0xb7},
+	{0xf0, 0x40},
+	{0xf1, 0x40},
+	{0xf2, 0x40},
+	{0xf3, 0x40},
+	{0x3f, 0x00},
+	{0xfd, 0x01},
+	{0x05, 0x00},
+	{0x06, 0xa6},
+	{0xfd, 0x01},
+};
+
+static const char * const ov02a10_test_pattern_menu[] = {
+	"Disabled",
+	"Eight Vertical Colour Bars",
+};
+
+static const s64 link_freq_menu_items[] = {
+	OV02A10_LINK_FREQ_390MHZ,
+};
+
+static u64 to_pixel_rate(u32 f_index)
+{
+	u64 pixel_rate = link_freq_menu_items[f_index] * 2 * OV02A10_DATA_LANES;
+
+	do_div(pixel_rate, OV02A10_BITS_PER_SAMPLE);
+
+	return pixel_rate;
+}
+
+static const struct ov02a10_mode supported_modes[] = {
+	{
+		.width = 1600,
+		.height = 1200,
+		.exp_def = 0x01ae,
+		.hts_def = 0x03a6,
+		.vts_def = 0x056e,
+		.reg_list = {
+			.num_of_regs = ARRAY_SIZE(ov02a10_1600x1200_regs),
+			.regs = ov02a10_1600x1200_regs,
+		},
+	},
+};
+
+static int ov02a10_write_array(struct ov02a10 *ov02a10,
+			       const struct ov02a10_reg_list *r_list)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < r_list->num_of_regs; i++) {
+		ret = i2c_smbus_write_byte_data(client, r_list->regs[i].addr,
+						r_list->regs[i].val);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int ov02a10_read_smbus(struct ov02a10 *ov02a10, unsigned char reg,
+			      unsigned char *val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = (unsigned char)ret;
+
+	return 0;
+}
+
+static void ov02a10_fill_fmt(const struct ov02a10_mode *mode,
+			     struct v4l2_mbus_framefmt *fmt)
+{
+	fmt->width = mode->width;
+	fmt->height = mode->height;
+	fmt->field = V4L2_FIELD_NONE;
+}
+
+static int ov02a10_set_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *fmt)
+{
+	struct ov02a10 *ov02a10 = to_ov02a10(sd);
+	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
+
+	mutex_lock(&ov02a10->mutex);
+
+	if (ov02a10->streaming) {
+		mutex_unlock(&ov02a10->mutex);
+		return -EBUSY;
+	}
+
+	/* Only one sensor mode supported */
+	mbus_fmt->code = ov02a10->fmt.code;
+	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
+	ov02a10->fmt = fmt->format;
+
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
+		*v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
+
+	mutex_unlock(&ov02a10->mutex);
+
+	return 0;
+}
+
+static int ov02a10_get_fmt(struct v4l2_subdev *sd,
+			   struct v4l2_subdev_pad_config *cfg,
+			   struct v4l2_subdev_format *fmt)
+{
+	struct ov02a10 *ov02a10 = to_ov02a10(sd);
+	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;
+
+	mutex_lock(&ov02a10->mutex);
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
+		fmt->format = *v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
+	} else {
+		fmt->format = ov02a10->fmt;
+		mbus_fmt->code = ov02a10->fmt.code;
+		ov02a10_fill_fmt(ov02a10->cur_mode, mbus_fmt);
+	}
+	mutex_unlock(&ov02a10->mutex);
+
+	return 0;
+}
+
+static int ov02a10_enum_mbus_code(struct v4l2_subdev *sd,
+				  struct v4l2_subdev_pad_config *cfg,
+				  struct v4l2_subdev_mbus_code_enum *code)
+{
+	struct ov02a10 *ov02a10 = to_ov02a10(sd);
+
+	if (code->index != 0)
+		return -EINVAL;
+
+	code->code = ov02a10->fmt.code;
+
+	return 0;
+}
+
+static int ov02a10_enum_frame_sizes(struct v4l2_subdev *sd,
+				    struct v4l2_subdev_pad_config *cfg,
+				    struct v4l2_subdev_frame_size_enum *fse)
+{
+	if (fse->index >= ARRAY_SIZE(supported_modes))
+		return -EINVAL;
+
+	fse->min_width  = supported_modes[fse->index].width;
+	fse->max_width  = supported_modes[fse->index].width;
+	fse->max_height = supported_modes[fse->index].height;
+	fse->min_height = supported_modes[fse->index].height;
+
+	return 0;
+}
+
+static int ov02a10_check_sensor_id(struct ov02a10 *ov02a10)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	u16 id;
+	u8 chip_id_h;
+	u8 chip_id_l;
+	int ret;
+
+	/* Check sensor revision */
+	ret = ov02a10_read_smbus(ov02a10, OV02A10_REG_CHIP_ID_H, &chip_id_h);
+	if (ret)
+		return ret;
+
+	ret = ov02a10_read_smbus(ov02a10, OV02A10_REG_CHIP_ID_L, &chip_id_l);
+	if (ret)
+		return ret;
+
+	id = (chip_id_h << 8) | chip_id_l;
+	if (id != CHIP_ID) {
+		dev_err(&client->dev, "Unexpected sensor id(%04x)\n", id);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ov02a10_power_on(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov02a10 *ov02a10 = to_ov02a10(sd);
+	int ret;
+
+	gpiod_set_value_cansleep(ov02a10->rst_gpio, 0);
+	gpiod_set_value_cansleep(ov02a10->pd_gpio, 0);
+
+	ret = clk_prepare_enable(ov02a10->eclk);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable eclk\n");
+		return ret;
+	}
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ov02a10_supply_names),
+				    ov02a10->supplies);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable regulators\n");
+		goto disable_clk;
+	}
+	usleep_range(5000, 6000);
+
+	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
+	usleep_range(5000, 6000);
+
+	gpiod_set_value_cansleep(ov02a10->rst_gpio, 1);
+	usleep_range(5000, 6000);
+
+	ret = ov02a10_check_sensor_id(ov02a10);
+	if (ret)
+		goto disable_regulator;
+
+	return 0;
+
+disable_regulator:
+	regulator_bulk_disable(ARRAY_SIZE(ov02a10_supply_names),
+			       ov02a10->supplies);
+disable_clk:
+	clk_disable_unprepare(ov02a10->eclk);
+
+	return ret;
+}
+
+static int ov02a10_power_off(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov02a10 *ov02a10 = to_ov02a10(sd);
+
+	gpiod_set_value_cansleep(ov02a10->rst_gpio, 0);
+	clk_disable_unprepare(ov02a10->eclk);
+	gpiod_set_value_cansleep(ov02a10->pd_gpio, 0);
+	regulator_bulk_disable(ARRAY_SIZE(ov02a10_supply_names),
+			       ov02a10->supplies);
+
+	return 0;
+}
+
+static int __ov02a10_start_stream(struct ov02a10 *ov02a10)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	const struct ov02a10_reg_list *reg_list;
+	int ret;
+
+	/* Apply default values of current mode */
+	reg_list = &ov02a10->cur_mode->reg_list;
+	ret = ov02a10_write_array(ov02a10, reg_list);
+	if (ret)
+		return ret;
+
+	/* Apply customized values from user */
+	ret = __v4l2_ctrl_handler_setup(ov02a10->subdev.ctrl_handler);
+	if (ret)
+		return ret;
+
+	/* Set orientation to 180 degree */
+	if (ov02a10->upside_down) {
+		ret = i2c_smbus_write_byte_data(client, REG_MIRROR_FLIP_CONTROL,
+						REG_MIRROR_FLIP_ENABLE);
+		if (ret) {
+			dev_err(&client->dev, "failed to set orientation\n");
+			return ret;
+		}
+		ret = i2c_smbus_write_byte_data(client, REG_GLOBAL_EFFECTIVE,
+						REG_ENABLE);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set mipi TX speed according to DT property */
+	if (ov02a10->mipi_clock_tx_speed != OV02A10_MIPI_TX_SPEED_DEFAULT) {
+		ret = i2c_smbus_write_byte_data(client, TX_SPEED_AREA_SEL,
+						ov02a10->mipi_clock_tx_speed);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Set stream on register */
+	return i2c_smbus_write_byte_data(client, REG_SC_CTRL_MODE,
+					 SC_CTRL_MODE_STREAMING);
+}
+
+static int __ov02a10_stop_stream(struct ov02a10 *ov02a10)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+
+	return i2c_smbus_write_byte_data(client, REG_SC_CTRL_MODE,
+					 SC_CTRL_MODE_STANDBY);
+}
+
+static int ov02a10_entity_init_cfg(struct v4l2_subdev *sd,
+				   struct v4l2_subdev_pad_config *cfg)
+{
+	struct v4l2_subdev_format fmt = {
+		.which = cfg ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE,
+		.format = {
+			.width = 1600,
+			.height = 1200,
+		}
+	};
+
+	ov02a10_set_fmt(sd, cfg, &fmt);
+
+	return 0;
+}
+
+static int ov02a10_s_stream(struct v4l2_subdev *sd, int on)
+{
+	struct ov02a10 *ov02a10 = to_ov02a10(sd);
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	int ret;
+
+	mutex_lock(&ov02a10->mutex);
+
+	if (ov02a10->streaming == on)
+		goto unlock_and_return;
+
+	if (on) {
+		ret = pm_runtime_get_sync(&client->dev);
+		if (ret < 0) {
+			pm_runtime_put_noidle(&client->dev);
+			goto unlock_and_return;
+		}
+
+		ret = __ov02a10_start_stream(ov02a10);
+		if (ret) {
+			__ov02a10_stop_stream(ov02a10);
+			ov02a10->streaming = !on;
+			goto err_rpm_put;
+		}
+	} else {
+		__ov02a10_stop_stream(ov02a10);
+		pm_runtime_put(&client->dev);
+	}
+
+	ov02a10->streaming = on;
+	mutex_unlock(&ov02a10->mutex);
+
+	return 0;
+
+err_rpm_put:
+	pm_runtime_put(&client->dev);
+unlock_and_return:
+	mutex_unlock(&ov02a10->mutex);
+
+	return ret;
+}
+
+static const struct dev_pm_ops ov02a10_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(ov02a10_power_off, ov02a10_power_on, NULL)
+};
+
+/*
+ * ov02a10_set_exposure - Function called when setting exposure time
+ * @priv: Pointer to device structure
+ * @val: Variable for exposure time, in the unit of micro-second
+ *
+ * Set exposure time based on input value.
+ *
+ * Return: 0 on success
+ */
+static int ov02a10_set_exposure(struct ov02a10 *ov02a10, int val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, REG_PAGE_SWITCH, REG_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, OV02A10_REG_EXPOSURE_H,
+					val >> OV02A10_EXP_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, OV02A10_REG_EXPOSURE_L, val);
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(client, REG_GLOBAL_EFFECTIVE,
+					 REG_ENABLE);
+}
+
+static int ov02a10_set_gain(struct ov02a10 *ov02a10, int val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, REG_PAGE_SWITCH, REG_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, OV02A10_REG_GAIN, val);
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(client, REG_GLOBAL_EFFECTIVE,
+					 REG_ENABLE);
+}
+
+static int ov02a10_set_vblank(struct ov02a10 *ov02a10, int val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	u32 vts = val + ov02a10->cur_mode->height - OV02A10_BASIC_LINE;
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, REG_PAGE_SWITCH, REG_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, OV02A10_REG_VTS_H,
+					vts >> OV02A10_VTS_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, OV02A10_REG_VTS_L, vts);
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(client, REG_GLOBAL_EFFECTIVE,
+					 REG_ENABLE);
+}
+
+static int ov02a10_set_test_pattern(struct ov02a10 *ov02a10, int pattern)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, REG_PAGE_SWITCH, REG_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, OV02A10_REG_TEST_PATTERN,
+					pattern);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte_data(client, REG_GLOBAL_EFFECTIVE,
+					REG_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(client, REG_SC_CTRL_MODE,
+					 SC_CTRL_MODE_STREAMING);
+}
+
+static int ov02a10_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct ov02a10 *ov02a10 = container_of(ctrl->handler,
+					       struct ov02a10, ctrl_handler);
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	s64 max_expo;
+	int ret;
+
+	/* Propagate change of current control to all related controls */
+	if (ctrl->id == V4L2_CID_VBLANK) {
+		/* Update max exposure while meeting expected vblanking */
+		max_expo = ov02a10->cur_mode->height + ctrl->val -
+			   OV02A10_EXPOSURE_MAX_MARGIN;
+		__v4l2_ctrl_modify_range(ov02a10->exposure,
+					 ov02a10->exposure->minimum, max_expo,
+					 ov02a10->exposure->step,
+					 ov02a10->exposure->default_value);
+	}
+
+	/* V4L2 controls values will be applied only when power is already up */
+	if (!pm_runtime_get_if_in_use(&client->dev))
+		return 0;
+
+	switch (ctrl->id) {
+	case V4L2_CID_EXPOSURE:
+		ret = ov02a10_set_exposure(ov02a10, ctrl->val);
+		break;
+	case V4L2_CID_ANALOGUE_GAIN:
+		ret = ov02a10_set_gain(ov02a10, ctrl->val);
+		break;
+	case V4L2_CID_VBLANK:
+		ret = ov02a10_set_vblank(ov02a10, ctrl->val);
+		break;
+	case V4L2_CID_TEST_PATTERN:
+		ret = ov02a10_set_test_pattern(ov02a10, ctrl->val);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	};
+
+	pm_runtime_put(&client->dev);
+
+	return ret;
+}
+
+static const struct v4l2_subdev_video_ops ov02a10_video_ops = {
+	.s_stream = ov02a10_s_stream,
+};
+
+static const struct v4l2_subdev_pad_ops ov02a10_pad_ops = {
+	.init_cfg = ov02a10_entity_init_cfg,
+	.enum_mbus_code = ov02a10_enum_mbus_code,
+	.enum_frame_size = ov02a10_enum_frame_sizes,
+	.get_fmt = ov02a10_get_fmt,
+	.set_fmt = ov02a10_set_fmt,
+};
+
+static const struct v4l2_subdev_ops ov02a10_subdev_ops = {
+	.video	= &ov02a10_video_ops,
+	.pad	= &ov02a10_pad_ops,
+};
+
+static const struct media_entity_operations ov02a10_subdev_entity_ops = {
+	.link_validate = v4l2_subdev_link_validate,
+};
+
+static const struct v4l2_ctrl_ops ov02a10_ctrl_ops = {
+	.s_ctrl = ov02a10_set_ctrl,
+};
+
+static int ov02a10_initialize_controls(struct ov02a10 *ov02a10)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&ov02a10->subdev);
+	const struct ov02a10_mode *mode;
+	struct v4l2_ctrl_handler *handler;
+	struct v4l2_ctrl *ctrl;
+	s64 exposure_max;
+	s64 vblank_def;
+	s64 pixel_rate;
+	s64 h_blank;
+	int ret;
+
+	handler = &ov02a10->ctrl_handler;
+	mode = ov02a10->cur_mode;
+	ret = v4l2_ctrl_handler_init(handler, 7);
+	if (ret)
+		return ret;
+
+	handler->lock = &ov02a10->mutex;
+
+	ctrl = v4l2_ctrl_new_int_menu(handler, NULL, V4L2_CID_LINK_FREQ, 0, 0,
+				      link_freq_menu_items);
+	if (ctrl)
+		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	pixel_rate = to_pixel_rate(0);
+	v4l2_ctrl_new_std(handler, NULL, V4L2_CID_PIXEL_RATE, 0, pixel_rate, 1,
+			  pixel_rate);
+
+	h_blank = mode->hts_def - mode->width;
+	v4l2_ctrl_new_std(handler, NULL, V4L2_CID_HBLANK, h_blank, h_blank, 1,
+			  h_blank);
+
+	vblank_def = mode->vts_def - mode->height;
+	v4l2_ctrl_new_std(handler, &ov02a10_ctrl_ops, V4L2_CID_VBLANK,
+			  vblank_def, OV02A10_VTS_MAX - mode->height, 1,
+			  vblank_def);
+
+	exposure_max = mode->vts_def - 4;
+	ov02a10->exposure = v4l2_ctrl_new_std(handler, &ov02a10_ctrl_ops,
+					      V4L2_CID_EXPOSURE,
+					      OV02A10_EXPOSURE_MIN,
+					      exposure_max,
+					      OV02A10_EXPOSURE_STEP,
+					      mode->exp_def);
+
+	v4l2_ctrl_new_std(handler, &ov02a10_ctrl_ops,
+			  V4L2_CID_ANALOGUE_GAIN, OV02A10_GAIN_MIN,
+			  OV02A10_GAIN_MAX, OV02A10_GAIN_STEP,
+			  OV02A10_GAIN_DEFAULT);
+
+	v4l2_ctrl_new_std_menu_items(handler, &ov02a10_ctrl_ops,
+				     V4L2_CID_TEST_PATTERN,
+				     ARRAY_SIZE(ov02a10_test_pattern_menu) - 1,
+				     0, 0, ov02a10_test_pattern_menu);
+
+	if (handler->error) {
+		ret = handler->error;
+		dev_err(&client->dev, "failed to init controls(%d)\n", ret);
+		goto err_free_handler;
+	}
+
+	ov02a10->subdev.ctrl_handler = handler;
+
+	return 0;
+
+err_free_handler:
+	v4l2_ctrl_handler_free(handler);
+
+	return ret;
+}
+
+static int ov02a10_check_hwcfg(struct device *dev, struct ov02a10 *ov02a10)
+{
+	struct fwnode_handle *ep;
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
+	struct v4l2_fwnode_endpoint bus_cfg = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY,
+	};
+	unsigned int i, j;
+	int ret;
+
+	if (!fwnode)
+		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.nr_of_link_frequencies) {
+		dev_err(dev, "no link frequencies defined");
+		ret = -EINVAL;
+		goto check_hwcfg_error;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(link_freq_menu_items); i++) {
+		for (j = 0; j < bus_cfg.nr_of_link_frequencies; j++) {
+			if (link_freq_menu_items[i] ==
+				bus_cfg.link_frequencies[j])
+				break;
+		}
+
+		if (j == bus_cfg.nr_of_link_frequencies) {
+			dev_err(dev, "no link frequency %lld supported",
+				link_freq_menu_items[i]);
+			ret = -EINVAL;
+			goto check_hwcfg_error;
+		}
+	}
+
+check_hwcfg_error:
+	v4l2_fwnode_endpoint_free(&bus_cfg);
+
+	return ret;
+}
+
+static int ov02a10_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct ov02a10 *ov02a10;
+	unsigned int rotation;
+	unsigned int clock_lane_tx_speed;
+	unsigned int i;
+	int ret;
+
+	ov02a10 = devm_kzalloc(dev, sizeof(*ov02a10), GFP_KERNEL);
+	if (!ov02a10)
+		return -ENOMEM;
+
+	ret = ov02a10_check_hwcfg(dev, ov02a10);
+	if (ret) {
+		dev_err(dev, "failed to check HW configuration: %d", ret);
+		return ret;
+	}
+
+	v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
+	ov02a10->mipi_clock_tx_speed = OV02A10_MIPI_TX_SPEED_DEFAULT;
+	ov02a10->fmt.code = MEDIA_BUS_FMT_SBGGR10_1X10;
+
+	/* Optional indication of physical rotation of sensor */
+	ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
+	if (!ret && rotation == 180) {
+		ov02a10->upside_down = true;
+		ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
+	}
+
+	/* Optional indication of mipi TX speed */
+	ret = fwnode_property_read_u32(dev_fwnode(dev), "ovti,mipi-tx-speed",
+				       &clock_lane_tx_speed);
+
+	if (!ret)
+		ov02a10->mipi_clock_tx_speed = clock_lane_tx_speed;
+
+	/* Get system clock (eclk) */
+	ov02a10->eclk = devm_clk_get(dev, "eclk");
+	if (IS_ERR(ov02a10->eclk)) {
+		ret = PTR_ERR(ov02a10->eclk);
+		dev_err(dev, "failed to get eclk %d\n", ret);
+		return ret;
+	}
+
+	ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
+				       &ov02a10->eclk_freq);
+	if (ret) {
+		dev_err(dev, "failed to get eclk frequency\n");
+		return ret;
+	}
+
+	ret = clk_set_rate(ov02a10->eclk, ov02a10->eclk_freq);
+	if (ret) {
+		dev_err(dev, "failed to set eclk frequency (24MHz)\n");
+		return ret;
+	}
+
+	if (clk_get_rate(ov02a10->eclk) != OV02A10_ECLK_FREQ) {
+		dev_warn(dev, "wrong eclk frequency %d Hz, expected: %d Hz\n",
+			 ov02a10->eclk_freq, OV02A10_ECLK_FREQ);
+		return -EINVAL;
+	}
+
+	ov02a10->pd_gpio = devm_gpiod_get(dev, "powerdown", GPIOD_OUT_HIGH);
+	if (IS_ERR(ov02a10->pd_gpio)) {
+		ret = PTR_ERR(ov02a10->pd_gpio);
+		dev_err(dev, "failed to get powerdown-gpios %d\n", ret);
+		return ret;
+	}
+
+	ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ov02a10->rst_gpio)) {
+		ret = PTR_ERR(ov02a10->rst_gpio);
+		dev_err(dev, "failed to get reset-gpios %d\n", ret);
+		return ret;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(ov02a10_supply_names); i++)
+		ov02a10->supplies[i].supply = ov02a10_supply_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov02a10_supply_names),
+				      ov02a10->supplies);
+	if (ret) {
+		dev_err(dev, "failed to get regulators\n");
+		return ret;
+	}
+
+	mutex_init(&ov02a10->mutex);
+	ov02a10->cur_mode = &supported_modes[0];
+	ret = ov02a10_initialize_controls(ov02a10);
+	if (ret) {
+		dev_err(dev, "failed to initialize controls\n");
+		goto err_destroy_mutex;
+	}
+
+	ov02a10->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+	ov02a10->subdev.entity.ops = &ov02a10_subdev_entity_ops;
+	ov02a10->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
+	ov02a10->pad.flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_pads_init(&ov02a10->subdev.entity, 1, &ov02a10->pad);
+	if (ret < 0) {
+		dev_err(dev, "failed to init entity pads: %d", ret);
+		goto err_free_handler;
+	}
+
+	pm_runtime_enable(dev);
+	if (!pm_runtime_enabled(dev)) {
+		ret = ov02a10_power_on(dev);
+		if (ret < 0) {
+			dev_err(dev, "failed to power on: %d\n", ret);
+			goto err_clean_entity;
+		}
+	}
+
+	ret = v4l2_async_register_subdev(&ov02a10->subdev);
+	if (ret) {
+		dev_err(dev, "failed to register V4L2 subdev: %d", ret);
+		goto err_power_off;
+	}
+
+	return 0;
+
+err_power_off:
+	pm_runtime_disable(dev);
+	if (!pm_runtime_enabled(dev))
+		ov02a10_power_off(dev);
+err_clean_entity:
+	media_entity_cleanup(&ov02a10->subdev.entity);
+err_free_handler:
+	v4l2_ctrl_handler_free(ov02a10->subdev.ctrl_handler);
+err_destroy_mutex:
+	mutex_destroy(&ov02a10->mutex);
+
+	return ret;
+}
+
+static int ov02a10_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+	struct ov02a10 *ov02a10 = to_ov02a10(sd);
+
+	v4l2_async_unregister_subdev(sd);
+	media_entity_cleanup(&sd->entity);
+	v4l2_ctrl_handler_free(sd->ctrl_handler);
+	pm_runtime_disable(&client->dev);
+	if (!pm_runtime_suspended(&client->dev))
+		ov02a10_power_off(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+	mutex_destroy(&ov02a10->mutex);
+
+	return 0;
+}
+
+static const struct of_device_id ov02a10_of_match[] = {
+	{ .compatible = "ovti,ov02a10" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, ov02a10_of_match);
+
+static struct i2c_driver ov02a10_i2c_driver = {
+	.driver = {
+		.name = "ov02a10",
+		.pm = &ov02a10_pm_ops,
+		.of_match_table = ov02a10_of_match,
+	},
+	.probe_new	= &ov02a10_probe,
+	.remove		= &ov02a10_remove,
+};
+
+module_i2c_driver(ov02a10_i2c_driver);
+
+MODULE_AUTHOR("Dongchun Zhu <[e-mail]>");
+MODULE_DESCRIPTION("OmniVision OV02A10 sensor driver");
+MODULE_LICENSE("GPL v2");
+