[v14,2/2] media: i2c: Add OV02A10 image sensor driver

Message ID 20200902120122.24456-3-dongchun.zhu@mediatek.com (mailing list archive)
State Superseded, archived
Delegated to: Sakari Ailus
Headers
Series media: i2c: Add support for OV02A10 sensor |

Commit Message

Dongchun Zhu Sept. 2, 2020, 12:01 p.m. UTC
  Add a V4L2 sub-device driver for OmniVision OV02A10 image sensor.

Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
---
 MAINTAINERS                 |    1 +
 drivers/media/i2c/Kconfig   |   13 +
 drivers/media/i2c/Makefile  |    1 +
 drivers/media/i2c/ov02a10.c | 1083 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 1098 insertions(+)
 create mode 100644 drivers/media/i2c/ov02a10.c
  

Comments

Andy Shevchenko Sept. 2, 2020, 1:44 p.m. UTC | #1
On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:
> Add a V4L2 sub-device driver for OmniVision OV02A10 image sensor.
> 

Some nit-picks below, after addressing, FWIW,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> ---
>  MAINTAINERS                 |    1 +
>  drivers/media/i2c/Kconfig   |   13 +
>  drivers/media/i2c/Makefile  |    1 +
>  drivers/media/i2c/ov02a10.c | 1083 +++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 1098 insertions(+)
>  create mode 100644 drivers/media/i2c/ov02a10.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 48aa7a7..ce7d8fa 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12724,6 +12724,7 @@ L:	linux-media@vger.kernel.org
>  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 <sakari.ailus@linux.intel.com>
> diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> index 48ae60a..f458804 100644
> --- a/drivers/media/i2c/Kconfig
> +++ b/drivers/media/i2c/Kconfig
> @@ -825,6 +825,19 @@ 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

Dunno if V4L2 modules allow COMPILE_TEST, but looking below, can we stick with one pattern like
	depends on VIDEO_V4L2 && I2C
?

Or is it the opposite (de facto in use)?

> +	select MEDIA_CONTROLLER
> +	select VIDEO_V4L2_SUBDEV_API
> +	select V4L2_FWNODE
> +	help
> +	  This is a Video4Linux2 sensor driver for the OmniVision
> +	  OV02A10 camera sensor.
> +
> +	  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 f0a7747..dc27e14 100644
> --- a/drivers/media/i2c/Makefile
> +++ b/drivers/media/i2c/Makefile
> @@ -64,6 +64,7 @@ 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..1f8c525
> --- /dev/null
> +++ b/drivers/media/i2c/ov02a10.c
> @@ -0,0 +1,1083 @@
> +// 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			0x04
> +
> +#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

Hex? (1)

> +#define OV02A10_BASIC_LINE				1224

Decimal? (2)

> +
> +#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

Not sure why these are in hex, but okay. Probably a reason behind (1) and (2)
as well.

> +/* Test pattern control */
> +#define OV02A10_REG_TEST_PATTERN			0xb6

I'm wondering if you can rearrange registers that they will be sorted by value.

> +#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;
> +	/* Indication of MIPI transmission speed select */
> +	u32 mipi_clock_voltage;
> +	/* Index of link frequency config to be used */
> +	u32 freq_index;
> +
> +	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, 0x04},
> +	{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;

No sure why you have casting and why returned value is not u8.

> +	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;
> +	struct v4l2_mbus_framefmt *frame_fmt;
> +	int ret = 0;
> +
> +	mutex_lock(&ov02a10->mutex);
> +
> +	if (ov02a10->streaming && fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> +		ret = -EBUSY;
> +		goto error;
> +	}
> +
> +	/* Only one sensor mode supported */
> +	mbus_fmt->code = ov02a10->fmt.code;
> +	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_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;
> +
> +error:

Like in other places be more precise

out_unlock:

> +	mutex_unlock(&ov02a10->mutex);
> +	return ret;
> +}
> +
> +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;

I'm wondering if above can be done in one bulk transfer (reading 16-bit value).

> +	id = (chip_id_h << 8) | chip_id_l;

If above can be achieved, this one should be rather something like
le16_to_cpu() (or be16) with corresponding type of chip_id.

> +	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 v4l2_subdev *sd = dev_get_drvdata(dev);

Same for the rest similar cases.

> +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> +	int ret;
> +
> +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 1);
> +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
> +
> +	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, 0);
> +	usleep_range(5000, 6000);
> +
> +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 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, 1);
> +	clk_disable_unprepare(ov02a10->eclk);
> +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
> +	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_voltage != OV02A10_MIPI_TX_SPEED_DEFAULT) {
> +		ret = i2c_smbus_write_byte_data(client, TX_SPEED_AREA_SEL,
> +						ov02a10->mipi_clock_voltage);
> +		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 = V4L2_SUBDEV_FORMAT_TRY,
> +		.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\n");
> +		ret = -EINVAL;
> +		goto check_hwcfg_error;
> +	}

If it's 0, the below will break on 'if (j == 0)' with slightly different but
informative enough message. What do you keep above check for?

> +	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]) {
> +				ov02a10->freq_index = i;
> +				break;
> +			}
> +		}
> +
> +		if (j == bus_cfg.nr_of_link_frequencies) {
> +			dev_err(dev, "no link frequency %lld supported\n",
> +				link_freq_menu_items[i]);
> +			ret = -EINVAL;

> +			goto check_hwcfg_error;

'break;' won't work?

> +		}
> +	}
> +
> +check_hwcfg_error:

out_endpoint_free:

> +	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 cnt = 0;
> +	unsigned int i;

> +	unsigned int num_freq_clk_volt = 2 * ARRAY_SIZE(link_freq_menu_items);

Can it be moved upper to improve readability?

> +	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\n", ret);
> +		return ret;
> +	}
> +
> +	v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> +	ov02a10->mipi_clock_voltage = 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) {

Can be simplified (but I'm fine with above):

	unsigned int rotation = 0;
	...
	fwnode_property_read_u32(..., &rotation);
	if (rotation == 180) {
		...
	}

> +		ov02a10->upside_down = true;
> +		ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> +	}
> +
> +	/* Optional indication of MIPI clock voltage unit */
> +	ret = fwnode_property_read_u32_array(dev_fwnode(dev),
> +					     "ovti,mipi-clock-voltage", NULL,
> +					     0);

	ret = fwnode_property_count_u32(...); // will be one line

> +	if (ret > 0 && ret % 2 == 0) {
> +		u32 freq_clk_volt[ret];
> +
> +		fwnode_property_read_u32_array(dev_fwnode(dev),
> +					       "ovti,mipi-clock-voltage",
> +					       freq_clk_volt,
> +					       ARRAY_SIZE(freq_clk_volt));
> +
> +		while (num_freq_clk_volt) {
> +			unsigned long freq;
> +			unsigned long volt;
> +
> +			if (cnt >= ARRAY_SIZE(freq_clk_volt)) {
> +				dev_warn(dev, "mismatched link frequency\n");
> +				break;
> +			}
> +

> +			freq = freq_clk_volt[cnt++] * 1000;

HZ_PER_KHZ?

> +			volt = freq_clk_volt[cnt++];
> +
> +			/* Get clock voltage unit value from DT */
> +			if (freq == link_freq_menu_items[ov02a10->freq_index]) {
> +				ov02a10->mipi_clock_voltage = volt;
> +				break;
> +			}
> +
> +			num_freq_clk_volt -= 2;
> +		}
> +	}
> +
> +	/* Get external input 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;

	return dev_err_probe(...);

> +	}
> +
> +	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, "eclk mismatched, mode is based on 24MHz\n");
> +		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;

	return dev_err_probe(...);

> +	}
> +
> +	ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
> +	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;

Ditto.

> +	}
> +
> +	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;

Ditto.

> +	}
> +
> +	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\n", ret);
> +		goto err_power_off;
> +	}
> +
> +	return 0;
> +
> +err_power_off:
> +	if (pm_runtime_enabled(dev))
> +		pm_runtime_disable(dev);
> +	else
> +		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_status_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,
> +};

> +

Redundant blank line.

> +module_i2c_driver(ov02a10_i2c_driver);
> +
> +MODULE_AUTHOR("Dongchun Zhu <dongchun.zhu@mediatek.com>");
> +MODULE_DESCRIPTION("OmniVision OV02A10 sensor driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.9.2
  
Andy Shevchenko Sept. 2, 2020, 1:51 p.m. UTC | #2
On Wed, Sep 02, 2020 at 04:44:21PM +0300, Andy Shevchenko wrote:
> On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:

> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);

> > +	ret = fwnode_property_read_u32_array(dev_fwnode(dev),

> > +		fwnode_property_read_u32_array(dev_fwnode(dev),

> > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",


Btw, can somebody explain, why it's fwnode API and not direct use of device property API?

In all above cases I see no reason why not to use device property API directly.
  
Dongchun Zhu Sept. 4, 2020, 1:22 p.m. UTC | #3
Hello Andy,

Thanks for the review.

On Wed, 2020-09-02 at 16:44 +0300, Andy Shevchenko wrote:
> On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:
> > Add a V4L2 sub-device driver for OmniVision OV02A10 image sensor.
> > 
> 
> Some nit-picks below, after addressing, FWIW,
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> > Signed-off-by: Dongchun Zhu <dongchun.zhu@mediatek.com>
> > ---
> >  MAINTAINERS                 |    1 +
> >  drivers/media/i2c/Kconfig   |   13 +
> >  drivers/media/i2c/Makefile  |    1 +
> >  drivers/media/i2c/ov02a10.c | 1083 +++++++++++++++++++++++++++++++++++++++++++
> >  4 files changed, 1098 insertions(+)
> >  create mode 100644 drivers/media/i2c/ov02a10.c
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 48aa7a7..ce7d8fa 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -12724,6 +12724,7 @@ L:	linux-media@vger.kernel.org
> >  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 <sakari.ailus@linux.intel.com>
> > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
> > index 48ae60a..f458804 100644
> > --- a/drivers/media/i2c/Kconfig
> > +++ b/drivers/media/i2c/Kconfig
> > @@ -825,6 +825,19 @@ 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
> 
> Dunno if V4L2 modules allow COMPILE_TEST, but looking below, can we stick with one pattern like
> 	depends on VIDEO_V4L2 && I2C
> ?
> 
> Or is it the opposite (de facto in use)?
> 

It seems there is no uniform standard for the dependency sequence
currently.

> > +	select MEDIA_CONTROLLER
> > +	select VIDEO_V4L2_SUBDEV_API
> > +	select V4L2_FWNODE
> > +	help
> > +	  This is a Video4Linux2 sensor driver for the OmniVision
> > +	  OV02A10 camera sensor.
> > +
> > +	  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 f0a7747..dc27e14 100644
> > --- a/drivers/media/i2c/Makefile
> > +++ b/drivers/media/i2c/Makefile
> > @@ -64,6 +64,7 @@ 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..1f8c525
> > --- /dev/null
> > +++ b/drivers/media/i2c/ov02a10.c
> > @@ -0,0 +1,1083 @@
> > +// 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			0x04
> > +
> > +#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
> 
> Hex? (1)
> 
> > +#define OV02A10_BASIC_LINE				1224
> 
> Decimal? (2)
> 
> > +
> > +#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
> 
> Not sure why these are in hex, but okay. Probably a reason behind (1) and (2)
> as well.
> 

From my perspective, OV02A10_BASIC_LINE is defined from the aspect of
'u32 height' in 'struct ov02a10_mode'; while the others are related with
sensor specific control registers, like VTS, GAIN, EXPSOURE...

> > +/* Test pattern control */
> > +#define OV02A10_REG_TEST_PATTERN			0xb6
> 
> I'm wondering if you can rearrange registers that they will be sorted by value.
> 

They are supposed to be classified by category.

> > +#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;
> > +	/* Indication of MIPI transmission speed select */
> > +	u32 mipi_clock_voltage;
> > +	/* Index of link frequency config to be used */
> > +	u32 freq_index;
> > +
> > +	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, 0x04},
> > +	{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;
> 
> No sure why you have casting and why returned value is not u8.
> 

Fine. 'unsigned char' would be replaced of 'u8' in next release.

> > +	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;
> > +	struct v4l2_mbus_framefmt *frame_fmt;
> > +	int ret = 0;
> > +
> > +	mutex_lock(&ov02a10->mutex);
> > +
> > +	if (ov02a10->streaming && fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> > +		ret = -EBUSY;
> > +		goto error;
> > +	}
> > +
> > +	/* Only one sensor mode supported */
> > +	mbus_fmt->code = ov02a10->fmt.code;
> > +	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_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;
> > +
> > +error:
> 
> Like in other places be more precise
> 
> out_unlock:
> 

Sounds good naming.
Fixed in next release.

> > +	mutex_unlock(&ov02a10->mutex);
> > +	return ret;
> > +}
> > +
> > +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;
> 
> I'm wondering if above can be done in one bulk transfer (reading 16-bit value).
> 
> > +	id = (chip_id_h << 8) | chip_id_l;
> 
> If above can be achieved, this one should be rather something like
> le16_to_cpu() (or be16) with corresponding type of chip_id.
> 

Yes. i2c_smbus_read_word_data() functions could read both registers in
using a single i2c transaction.
Let me try locally first.

> > +	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 v4l2_subdev *sd = dev_get_drvdata(dev);
> 
> Same for the rest similar cases.
> 

We've discussed the issue in DW9768 V2.

For V4L2 sub-device drivers, dev_get_drvdata() shouldn't be used
directly.

More details please check the Google Issue:
https://partnerissuetracker.corp.google.com/issues/147957975


> > +	struct ov02a10 *ov02a10 = to_ov02a10(sd);
> > +	int ret;
> > +
> > +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 1);
> > +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
> > +
> > +	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, 0);
> > +	usleep_range(5000, 6000);
> > +
> > +	gpiod_set_value_cansleep(ov02a10->rst_gpio, 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, 1);
> > +	clk_disable_unprepare(ov02a10->eclk);
> > +	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
> > +	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_voltage != OV02A10_MIPI_TX_SPEED_DEFAULT) {
> > +		ret = i2c_smbus_write_byte_data(client, TX_SPEED_AREA_SEL,
> > +						ov02a10->mipi_clock_voltage);
> > +		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 = V4L2_SUBDEV_FORMAT_TRY,
> > +		.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\n");
> > +		ret = -EINVAL;
> > +		goto check_hwcfg_error;
> > +	}
> 
> If it's 0, the below will break on 'if (j == 0)' with slightly different but
> informative enough message. What do you keep above check for?
> 

I still prefer to the original version.
If 'bus_cfg.nr_of_link_frequencies' is 0, shouldn't we directly return
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]) {
> > +				ov02a10->freq_index = i;
> > +				break;
> > +			}
> > +		}
> > +
> > +		if (j == bus_cfg.nr_of_link_frequencies) {
> > +			dev_err(dev, "no link frequency %lld supported\n",
> > +				link_freq_menu_items[i]);
> > +			ret = -EINVAL;
> 
> > +			goto check_hwcfg_error;
> 
> 'break;' won't work?
> 
> > +		}
> > +	}
> > +
> > +check_hwcfg_error:
> 
> out_endpoint_free:
> 

It seems that OV8856 keeps the same pattern.

> > +	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 cnt = 0;
> > +	unsigned int i;
> 
> > +	unsigned int num_freq_clk_volt = 2 * ARRAY_SIZE(link_freq_menu_items);
> 
> Can it be moved upper to improve readability?
> 

Fixed in next release.

> > +	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\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
> > +	ov02a10->mipi_clock_voltage = 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) {
> 
> Can be simplified (but I'm fine with above):
> 
> 	unsigned int rotation = 0;
> 	...
> 	fwnode_property_read_u32(..., &rotation);
> 	if (rotation == 180) {
> 		...
> 	}
> 

Sounds like the readability is improved using the latter style :-)

> > +		ov02a10->upside_down = true;
> > +		ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> > +	}
> > +
> > +	/* Optional indication of MIPI clock voltage unit */
> > +	ret = fwnode_property_read_u32_array(dev_fwnode(dev),
> > +					     "ovti,mipi-clock-voltage", NULL,
> > +					     0);
> 
> 	ret = fwnode_property_count_u32(...); // will be one line
> 

Great APIs!

> > +	if (ret > 0 && ret % 2 == 0) {
> > +		u32 freq_clk_volt[ret];
> > +
> > +		fwnode_property_read_u32_array(dev_fwnode(dev),
> > +					       "ovti,mipi-clock-voltage",
> > +					       freq_clk_volt,
> > +					       ARRAY_SIZE(freq_clk_volt));
> > +
> > +		while (num_freq_clk_volt) {
> > +			unsigned long freq;
> > +			unsigned long volt;
> > +
> > +			if (cnt >= ARRAY_SIZE(freq_clk_volt)) {
> > +				dev_warn(dev, "mismatched link frequency\n");
> > +				break;
> > +			}
> > +
> 
> > +			freq = freq_clk_volt[cnt++] * 1000;
> 
> HZ_PER_KHZ?
> 

Fixed in next release.

> > +			volt = freq_clk_volt[cnt++];
> > +
> > +			/* Get clock voltage unit value from DT */
> > +			if (freq == link_freq_menu_items[ov02a10->freq_index]) {
> > +				ov02a10->mipi_clock_voltage = volt;
> > +				break;
> > +			}
> > +
> > +			num_freq_clk_volt -= 2;
> > +		}
> > +	}
> > +
> > +	/* Get external input 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;
> 
> 	return dev_err_probe(...);
> 

Great APIs...

> > +	}
> > +
> > +	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, "eclk mismatched, mode is based on 24MHz\n");
> > +		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;
> 
> 	return dev_err_probe(...);
> 

It would be simplified using dev_err_probe directly in next release.

> > +	}
> > +
> > +	ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
> > +	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;
> 
> Ditto.
> 

Fixed in next release.

> > +	}
> > +
> > +	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;
> 
> Ditto.
> 

Fixed in next release.

> > +	}
> > +
> > +	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\n", ret);
> > +		goto err_power_off;
> > +	}
> > +
> > +	return 0;
> > +
> > +err_power_off:
> > +	if (pm_runtime_enabled(dev))
> > +		pm_runtime_disable(dev);
> > +	else
> > +		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_status_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,
> > +};
> 
> > +
> 
> Redundant blank line.
> 

Fixed in next release.

> > +module_i2c_driver(ov02a10_i2c_driver);
> > +
> > +MODULE_AUTHOR("Dongchun Zhu <dongchun.zhu@mediatek.com>");
> > +MODULE_DESCRIPTION("OmniVision OV02A10 sensor driver");
> > +MODULE_LICENSE("GPL v2");
> > -- 
> > 2.9.2
>
  
Dongchun Zhu Sept. 4, 2020, 1:32 p.m. UTC | #4
On Wed, 2020-09-02 at 16:51 +0300, Andy Shevchenko wrote:
> On Wed, Sep 02, 2020 at 04:44:21PM +0300, Andy Shevchenko wrote:
> > On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:
> 
> > > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> 
> > > +	ret = fwnode_property_read_u32_array(dev_fwnode(dev),
> 
> > > +		fwnode_property_read_u32_array(dev_fwnode(dev),
> 
> > > +	ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> 
> 
> Btw, can somebody explain, why it's fwnode API and not direct use of device property API?
> 
> In all above cases I see no reason why not to use device property API directly.
> 

From the fwnode API's usage:
@fwnode: Firmware node to get the property of.

It seems dev_fwnode(dev) could return dev->of_node->fwnode if CONFIG_OF
is enabled, or return dev->fwnode if not.
  
Andy Shevchenko Sept. 4, 2020, 1:55 p.m. UTC | #5
On Fri, Sep 4, 2020 at 4:38 PM Dongchun Zhu <dongchun.zhu@mediatek.com> wrote:
> On Wed, 2020-09-02 at 16:51 +0300, Andy Shevchenko wrote:
> > On Wed, Sep 02, 2020 at 04:44:21PM +0300, Andy Shevchenko wrote:
> > > On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:
> >
> > > > + ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> >
> > > > + ret = fwnode_property_read_u32_array(dev_fwnode(dev),
> >
> > > > +         fwnode_property_read_u32_array(dev_fwnode(dev),
> >
> > > > + ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> >
> >
> > Btw, can somebody explain, why it's fwnode API and not direct use of device property API?
> >
> > In all above cases I see no reason why not to use device property API directly.
> >
>
> From the fwnode API's usage:
> @fwnode: Firmware node to get the property of.
>
> It seems dev_fwnode(dev) could return dev->of_node->fwnode if CONFIG_OF
> is enabled, or return dev->fwnode if not.

So?..

Shouldn't be the above an equivalent to device_property_*(dev, ...)?
  
Andy Shevchenko Sept. 4, 2020, 2:05 p.m. UTC | #6
On Fri, Sep 4, 2020 at 4:48 PM Dongchun Zhu <dongchun.zhu@mediatek.com> wrote:
> On Wed, 2020-09-02 at 16:44 +0300, Andy Shevchenko wrote:
> > On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:

...

> > > +   struct i2c_client *client = to_i2c_client(dev);
> > > +   struct v4l2_subdev *sd = i2c_get_clientdata(client);
> >
> >       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> >
> > Same for the rest similar cases.
>
> We've discussed the issue in DW9768 V2.
>
> For V4L2 sub-device drivers, dev_get_drvdata() shouldn't be used
> directly.
>
> More details please check the Google Issue:
> https://partnerissuetracker.corp.google.com/issues/147957975

This is not a public link. Can you remind me what was the issue?

...

> > > +   if (!bus_cfg.nr_of_link_frequencies) {
> > > +           dev_err(dev, "no link frequencies defined\n");
> > > +           ret = -EINVAL;
> > > +           goto check_hwcfg_error;
> > > +   }
> >
> > If it's 0, the below will break on 'if (j == 0)' with slightly different but
> > informative enough message. What do you keep above check for?
>
> I still prefer to the original version.
> If 'bus_cfg.nr_of_link_frequencies' is 0, shouldn't we directly return
> error?

But that will happen anyway. I will leave this to Sakari and
maintainers to decide.

> > > +   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]) {
> > > +                           ov02a10->freq_index = i;
> > > +                           break;
> > > +                   }
> > > +           }
> > > +
> > > +           if (j == bus_cfg.nr_of_link_frequencies) {
> > > +                   dev_err(dev, "no link frequency %lld supported\n",
> > > +                           link_freq_menu_items[i]);
> > > +                   ret = -EINVAL;
> >
> > > +                   goto check_hwcfg_error;
> >
> > 'break;' won't work?
> >
> > > +           }
> > > +   }
> > > +
> > > +check_hwcfg_error:
> >
> > out_endpoint_free:
>
> It seems that OV8856 keeps the same pattern.

So, we can do better than that, right?

> > > +   v4l2_fwnode_endpoint_free(&bus_cfg);

...

> > > +   /* Optional indication of physical rotation of sensor */
> > > +   ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> > > +   if (!ret && rotation == 180) {
> >
> > Can be simplified (but I'm fine with above):
> >
> >       unsigned int rotation = 0;
> >       ...
> >       fwnode_property_read_u32(..., &rotation);
> >       if (rotation == 180) {
> >               ...
> >       }
> >
>
> Sounds like the readability is improved using the latter style :-)

Yes and makes it clear that this is an optional one.
Also you may consider the following

      unsigned int rotation;
      ...
      /* Optional ... */
      rotation = 0;
      fwnode_property_read_u32(..., &rotation);
      if (rotation == 180) {
          ...
      }

> > > +           ov02a10->upside_down = true;
> > > +           ov02a10->fmt.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> > > +   }
  
Tomasz Figa Sept. 7, 2020, 1:15 p.m. UTC | #7
On Fri, Sep 4, 2020 at 4:06 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Fri, Sep 4, 2020 at 4:48 PM Dongchun Zhu <dongchun.zhu@mediatek.com> wrote:
> > On Wed, 2020-09-02 at 16:44 +0300, Andy Shevchenko wrote:
> > > On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:
>
> ...
>
> > > > +   struct i2c_client *client = to_i2c_client(dev);
> > > > +   struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > >
> > >       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > >
> > > Same for the rest similar cases.
> >
> > We've discussed the issue in DW9768 V2.
> >
> > For V4L2 sub-device drivers, dev_get_drvdata() shouldn't be used
> > directly.
> >
> > More details please check the Google Issue:
> > https://partnerissuetracker.corp.google.com/issues/147957975
>
> This is not a public link. Can you remind me what was the issue?
>

v4l2-subdev framework uses dev drvdata for its own purposes. However,
that problem was about the driver setting its own drvdata and having
it overridden by the framework. There is nothing wrong in using
dev_get_drvdata(), assuming the correct type is known and here it's
guaranteed to be v4l2_subdev for the v4l2-subdev framework.

In fact i2c_get_clientdata() [1] is just a wrapper that calls
dev_get_drvdata(&client->dev).

[1] https://elixir.bootlin.com/linux/v5.9-rc3/source/include/linux/i2c.h#L351

> ...
>
> > > > +   if (!bus_cfg.nr_of_link_frequencies) {
> > > > +           dev_err(dev, "no link frequencies defined\n");
> > > > +           ret = -EINVAL;
> > > > +           goto check_hwcfg_error;
> > > > +   }
> > >
> > > If it's 0, the below will break on 'if (j == 0)' with slightly different but
> > > informative enough message. What do you keep above check for?
> >
> > I still prefer to the original version.
> > If 'bus_cfg.nr_of_link_frequencies' is 0, shouldn't we directly return
> > error?
>
> But that will happen anyway. I will leave this to Sakari and
> maintainers to decide.
>

I agree with Andy on this. The check is redundant. In fact, the later
error message is more meaningful, because it at least suggests a
frequency that must be supported, while the earlier one only states
the fact.

Best regards,
Tomasz
  
Andy Shevchenko Sept. 7, 2020, 1:51 p.m. UTC | #8
On Mon, Sep 07, 2020 at 03:15:17PM +0200, Tomasz Figa wrote:
> On Fri, Sep 4, 2020 at 4:06 PM Andy Shevchenko
> <andy.shevchenko@gmail.com> wrote:
> > On Fri, Sep 4, 2020 at 4:48 PM Dongchun Zhu <dongchun.zhu@mediatek.com> wrote:
> > > On Wed, 2020-09-02 at 16:44 +0300, Andy Shevchenko wrote:
> > > > On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:

...

> > > > > +   struct i2c_client *client = to_i2c_client(dev);
> > > > > +   struct v4l2_subdev *sd = i2c_get_clientdata(client);
> > > >
> > > >       struct v4l2_subdev *sd = dev_get_drvdata(dev);
> > > >
> > > > Same for the rest similar cases.
> > >
> > > We've discussed the issue in DW9768 V2.
> > >
> > > For V4L2 sub-device drivers, dev_get_drvdata() shouldn't be used
> > > directly.
> > >
> > > More details please check the Google Issue:
> > > https://partnerissuetracker.corp.google.com/issues/147957975
> >
> > This is not a public link. Can you remind me what was the issue?
> >
> 
> v4l2-subdev framework uses dev drvdata for its own purposes. However,
> that problem was about the driver setting its own drvdata and having
> it overridden by the framework. There is nothing wrong in using
> dev_get_drvdata(), assuming the correct type is known and here it's
> guaranteed to be v4l2_subdev for the v4l2-subdev framework.
> 
> In fact i2c_get_clientdata() [1] is just a wrapper that calls
> dev_get_drvdata(&client->dev).

And funny future would be that if we don't do this now we will have plenty of
janitors to DoS attack us with the fix in the future.

> [1] https://elixir.bootlin.com/linux/v5.9-rc3/source/include/linux/i2c.h#L351
  
Sakari Ailus Sept. 8, 2020, 9:46 a.m. UTC | #9
Hi Andy,

On Fri, Sep 04, 2020 at 04:55:56PM +0300, Andy Shevchenko wrote:
> On Fri, Sep 4, 2020 at 4:38 PM Dongchun Zhu <dongchun.zhu@mediatek.com> wrote:
> > On Wed, 2020-09-02 at 16:51 +0300, Andy Shevchenko wrote:
> > > On Wed, Sep 02, 2020 at 04:44:21PM +0300, Andy Shevchenko wrote:
> > > > On Wed, Sep 02, 2020 at 08:01:22PM +0800, Dongchun Zhu wrote:
> > >
> > > > > + ret = fwnode_property_read_u32(dev_fwnode(dev), "rotation", &rotation);
> > >
> > > > > + ret = fwnode_property_read_u32_array(dev_fwnode(dev),
> > >
> > > > > +         fwnode_property_read_u32_array(dev_fwnode(dev),
> > >
> > > > > + ret = fwnode_property_read_u32(dev_fwnode(dev), "clock-frequency",
> > >
> > >
> > > Btw, can somebody explain, why it's fwnode API and not direct use of device property API?
> > >
> > > In all above cases I see no reason why not to use device property API directly.
> > >
> >
> > From the fwnode API's usage:
> > @fwnode: Firmware node to get the property of.
> >
> > It seems dev_fwnode(dev) could return dev->of_node->fwnode if CONFIG_OF
> > is enabled, or return dev->fwnode if not.
> 
> So?..
> 
> Shouldn't be the above an equivalent to device_property_*(dev, ...)?

Yes.

V4L2 does not have a dummy implementation for almost no V4L2 driver has no
use without V4L2.
  

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 48aa7a7..ce7d8fa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12724,6 +12724,7 @@  L:	linux-media@vger.kernel.org
 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 <sakari.ailus@linux.intel.com>
diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index 48ae60a..f458804 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -825,6 +825,19 @@  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 sensor.
+
+	  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 f0a7747..dc27e14 100644
--- a/drivers/media/i2c/Makefile
+++ b/drivers/media/i2c/Makefile
@@ -64,6 +64,7 @@  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..1f8c525
--- /dev/null
+++ b/drivers/media/i2c/ov02a10.c
@@ -0,0 +1,1083 @@ 
+// 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			0x04
+
+#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;
+	/* Indication of MIPI transmission speed select */
+	u32 mipi_clock_voltage;
+	/* Index of link frequency config to be used */
+	u32 freq_index;
+
+	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, 0x04},
+	{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;
+	struct v4l2_mbus_framefmt *frame_fmt;
+	int ret = 0;
+
+	mutex_lock(&ov02a10->mutex);
+
+	if (ov02a10->streaming && fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
+		ret = -EBUSY;
+		goto error;
+	}
+
+	/* Only one sensor mode supported */
+	mbus_fmt->code = ov02a10->fmt.code;
+	ov02a10_fill_fmt(ov02a10->cur_mode, mbus_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;
+
+error:
+	mutex_unlock(&ov02a10->mutex);
+	return ret;
+}
+
+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, 1);
+	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
+
+	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, 0);
+	usleep_range(5000, 6000);
+
+	gpiod_set_value_cansleep(ov02a10->rst_gpio, 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, 1);
+	clk_disable_unprepare(ov02a10->eclk);
+	gpiod_set_value_cansleep(ov02a10->pd_gpio, 1);
+	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_voltage != OV02A10_MIPI_TX_SPEED_DEFAULT) {
+		ret = i2c_smbus_write_byte_data(client, TX_SPEED_AREA_SEL,
+						ov02a10->mipi_clock_voltage);
+		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 = V4L2_SUBDEV_FORMAT_TRY,
+		.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\n");
+		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]) {
+				ov02a10->freq_index = i;
+				break;
+			}
+		}
+
+		if (j == bus_cfg.nr_of_link_frequencies) {
+			dev_err(dev, "no link frequency %lld supported\n",
+				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 cnt = 0;
+	unsigned int i;
+	unsigned int num_freq_clk_volt = 2 * ARRAY_SIZE(link_freq_menu_items);
+	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\n", ret);
+		return ret;
+	}
+
+	v4l2_i2c_subdev_init(&ov02a10->subdev, client, &ov02a10_subdev_ops);
+	ov02a10->mipi_clock_voltage = 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 clock voltage unit */
+	ret = fwnode_property_read_u32_array(dev_fwnode(dev),
+					     "ovti,mipi-clock-voltage", NULL,
+					     0);
+	if (ret > 0 && ret % 2 == 0) {
+		u32 freq_clk_volt[ret];
+
+		fwnode_property_read_u32_array(dev_fwnode(dev),
+					       "ovti,mipi-clock-voltage",
+					       freq_clk_volt,
+					       ARRAY_SIZE(freq_clk_volt));
+
+		while (num_freq_clk_volt) {
+			unsigned long freq;
+			unsigned long volt;
+
+			if (cnt >= ARRAY_SIZE(freq_clk_volt)) {
+				dev_warn(dev, "mismatched link frequency\n");
+				break;
+			}
+
+			freq = freq_clk_volt[cnt++] * 1000;
+			volt = freq_clk_volt[cnt++];
+
+			/* Get clock voltage unit value from DT */
+			if (freq == link_freq_menu_items[ov02a10->freq_index]) {
+				ov02a10->mipi_clock_voltage = volt;
+				break;
+			}
+
+			num_freq_clk_volt -= 2;
+		}
+	}
+
+	/* Get external input 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, "eclk mismatched, mode is based on 24MHz\n");
+		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_HIGH);
+	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\n", ret);
+		goto err_power_off;
+	}
+
+	return 0;
+
+err_power_off:
+	if (pm_runtime_enabled(dev))
+		pm_runtime_disable(dev);
+	else
+		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_status_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 <dongchun.zhu@mediatek.com>");
+MODULE_DESCRIPTION("OmniVision OV02A10 sensor driver");
+MODULE_LICENSE("GPL v2");