// SPDX-License-Identifier: GPL-2.0
/*
 * ov2685 driver
 *
 * Copyright (C) 2017 Fuzhou Rockchip Electronics Co., Ltd.
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/delay.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 <linux/sysfs.h>
#include <media/media-entity.h>
#include <media/v4l2-async.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-subdev.h>

#define CHIP_ID				0x2685
#define OV2685_REG_CHIP_ID		0x300a

#define OV2685_XVCLK_FREQ		24000000

#define REG_SC_CTRL_MODE		0x0100
#define     SC_CTRL_MODE_STANDBY	0x0
#define     SC_CTRL_MODE_STREAMING	BIT(0)

#define OV2685_REG_EXPOSURE		0x3500
#define	OV2685_EXPOSURE_MIN		4
#define	OV2685_EXPOSURE_STEP		1

#define OV2685_REG_VTS			0x380e
#define OV2685_VTS_MAX			0x7fff

#define OV2685_REG_GAIN			0x350a
#define OV2685_GAIN_MIN			0
#define OV2685_GAIN_MAX			0x07ff
#define OV2685_GAIN_STEP		0x1
#define OV2685_GAIN_DEFAULT		0x0036

#define OV2685_REG_TEST_PATTERN		0x5080
#define OV2685_TEST_PATTERN_DISABLED		0x00
#define OV2685_TEST_PATTERN_COLOR_BAR		0x80
#define OV2685_TEST_PATTERN_RANDOM		0x81
#define OV2685_TEST_PATTERN_COLOR_BAR_FADE	0x88
#define OV2685_TEST_PATTERN_BW_SQUARE		0x92
#define OV2685_TEST_PATTERN_COLOR_SQUARE	0x82

#define REG_NULL			0xFFFF

#define OV2685_REG_VALUE_08BIT		1
#define OV2685_REG_VALUE_16BIT		2
#define OV2685_REG_VALUE_24BIT		3

#define OV2685_NATIVE_WIDTH		1616
#define OV2685_NATIVE_HEIGHT		1216

#define OV2685_LANES			1
#define OV2685_BITS_PER_SAMPLE		10

static const char * const ov2685_supply_names[] = {
	"avdd",		/* Analog power */
	"dovdd",	/* Digital I/O power */
	"dvdd",		/* Digital core power */
};

#define OV2685_NUM_SUPPLIES ARRAY_SIZE(ov2685_supply_names)

struct regval {
	u16 addr;
	u8 val;
};

struct ov2685_mode {
	u32 width;
	u32 height;
	u32 exp_def;
	u32 hts_def;
	u32 vts_def;
	const struct v4l2_rect *analog_crop;
	const struct regval *reg_list;
};

struct ov2685 {
	struct i2c_client	*client;
	struct clk		*xvclk;
	struct gpio_desc	*reset_gpio;
	struct regulator_bulk_data supplies[OV2685_NUM_SUPPLIES];

	struct mutex		mutex;
	struct v4l2_subdev	subdev;
	struct media_pad	pad;
	struct v4l2_ctrl	*anal_gain;
	struct v4l2_ctrl	*exposure;
	struct v4l2_ctrl	*hblank;
	struct v4l2_ctrl	*vblank;
	struct v4l2_ctrl	*test_pattern;
	struct v4l2_ctrl_handler ctrl_handler;

	const struct ov2685_mode *cur_mode;
};

#define to_ov2685(sd) container_of(sd, struct ov2685, subdev)

/* PLL settings bases on 24M xvclk */
static struct regval ov2685_1600x1200_regs[] = {
	{0x0103, 0x01},
	{0x0100, 0x00},
	{0x3002, 0x00},
	{0x3016, 0x1c},
	{0x3018, 0x44},
	{0x301d, 0xf0},
	{0x3020, 0x00},
	{0x3082, 0x37},
	{0x3083, 0x03},
	{0x3084, 0x09},
	{0x3085, 0x04},
	{0x3086, 0x00},
	{0x3087, 0x00},
	{0x3501, 0x4e},
	{0x3502, 0xe0},
	{0x3503, 0x27},
	{0x350b, 0x36},
	{0x3600, 0xb4},
	{0x3603, 0x35},
	{0x3604, 0x24},
	{0x3605, 0x00},
	{0x3620, 0x24},
	{0x3621, 0x34},
	{0x3622, 0x03},
	{0x3628, 0x10},
	{0x3705, 0x3c},
	{0x370a, 0x21},
	{0x370c, 0x50},
	{0x370d, 0xc0},
	{0x3717, 0x58},
	{0x3718, 0x80},
	{0x3720, 0x00},
	{0x3721, 0x09},
	{0x3722, 0x06},
	{0x3723, 0x59},
	{0x3738, 0x99},
	{0x3781, 0x80},
	{0x3784, 0x0c},
	{0x3789, 0x60},
	{0x3800, 0x00},
	{0x3801, 0x00},
	{0x3802, 0x00},
	{0x3803, 0x00},
	{0x3804, 0x06},
	{0x3805, 0x4f},
	{0x3806, 0x04},
	{0x3807, 0xbf},
	{0x3808, 0x06},
	{0x3809, 0x40},
	{0x380a, 0x04},
	{0x380b, 0xb0},
	{0x380c, 0x06},
	{0x380d, 0xa4},
	{0x380e, 0x05},
	{0x380f, 0x0e},
	{0x3810, 0x00},
	{0x3811, 0x08},
	{0x3812, 0x00},
	{0x3813, 0x08},
	{0x3814, 0x11},
	{0x3815, 0x11},
	{0x3819, 0x04},
	{0x3820, 0xc0},
	{0x3821, 0x00},
	{0x3a06, 0x01},
	{0x3a07, 0x84},
	{0x3a08, 0x01},
	{0x3a09, 0x43},
	{0x3a0a, 0x24},
	{0x3a0b, 0x60},
	{0x3a0c, 0x28},
	{0x3a0d, 0x60},
	{0x3a0e, 0x04},
	{0x3a0f, 0x8c},
	{0x3a10, 0x05},
	{0x3a11, 0x0c},
	{0x4000, 0x81},
	{0x4001, 0x40},
	{0x4008, 0x02},
	{0x4009, 0x09},
	{0x4300, 0x00},
	{0x430e, 0x00},
	{0x4602, 0x02},
	{0x481b, 0x40},
	{0x481f, 0x40},
	{0x4837, 0x18},
	{0x5000, 0x1f},
	{0x5001, 0x05},
	{0x5002, 0x30},
	{0x5003, 0x04},
	{0x5004, 0x00},
	{0x5005, 0x0c},
	{0x5280, 0x15},
	{0x5281, 0x06},
	{0x5282, 0x06},
	{0x5283, 0x08},
	{0x5284, 0x1c},
	{0x5285, 0x1c},
	{0x5286, 0x20},
	{0x5287, 0x10},
	{REG_NULL, 0x00}
};

#define OV2685_LINK_FREQ_330MHZ		330000000
static const s64 link_freq_menu_items[] = {
	OV2685_LINK_FREQ_330MHZ
};

static const char * const ov2685_test_pattern_menu[] = {
	"Disabled",
	"Color Bar",
	"Color Bar FADE",
	"Random Data",
	"Black White Square",
	"Color Square"
};

static const int ov2685_test_pattern_val[] = {
	OV2685_TEST_PATTERN_DISABLED,
	OV2685_TEST_PATTERN_COLOR_BAR,
	OV2685_TEST_PATTERN_COLOR_BAR_FADE,
	OV2685_TEST_PATTERN_RANDOM,
	OV2685_TEST_PATTERN_BW_SQUARE,
	OV2685_TEST_PATTERN_COLOR_SQUARE,
};

static const struct v4l2_rect ov2685_analog_crop = {
	.left	= 8,
	.top	= 8,
	.width	= 1600,
	.height	= 1200,
};

static const struct ov2685_mode supported_modes[] = {
	{
		.width = 1600,
		.height = 1200,
		.exp_def = 0x04ee,
		.hts_def = 0x06a4,
		.vts_def = 0x050e,
		.analog_crop = &ov2685_analog_crop,
		.reg_list = ov2685_1600x1200_regs,
	},
};

/* Write registers up to 4 at a time */
static int ov2685_write_reg(struct i2c_client *client, u16 reg,
			    u32 len, u32 val)
{
	u32 val_i, buf_i;
	u8 buf[6];
	u8 *val_p;
	__be32 val_be;

	if (len > 4)
		return -EINVAL;

	buf[0] = reg >> 8;
	buf[1] = reg & 0xff;

	val_be = cpu_to_be32(val);
	val_p = (u8 *)&val_be;
	buf_i = 2;
	val_i = 4 - len;

	while (val_i < 4)
		buf[buf_i++] = val_p[val_i++];

	if (i2c_master_send(client, buf, len + 2) != len + 2)
		return -EIO;

	return 0;
}

static int ov2685_write_array(struct i2c_client *client,
			      const struct regval *regs)
{
	int ret = 0;
	u32 i;

	for (i = 0; ret == 0 && regs[i].addr != REG_NULL; i++)
		ret = ov2685_write_reg(client, regs[i].addr,
				       OV2685_REG_VALUE_08BIT, regs[i].val);

	return ret;
}

/* Read registers up to 4 at a time */
static int ov2685_read_reg(struct i2c_client *client, u16 reg,
			   u32 len, u32 *val)
{
	struct i2c_msg msgs[2];
	u8 *data_be_p;
	__be32 data_be = 0;
	__be16 reg_addr_be = cpu_to_be16(reg);
	int ret;

	if (len > 4)
		return -EINVAL;

	data_be_p = (u8 *)&data_be;
	/* Write register address */
	msgs[0].addr = client->addr;
	msgs[0].flags = 0;
	msgs[0].len = 2;
	msgs[0].buf = (u8 *)&reg_addr_be;

	/* Read data from register */
	msgs[1].addr = client->addr;
	msgs[1].flags = I2C_M_RD;
	msgs[1].len = len;
	msgs[1].buf = &data_be_p[4 - len];

	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret != ARRAY_SIZE(msgs))
		return -EIO;

	*val = be32_to_cpu(data_be);

	return 0;
}

static void ov2685_fill_fmt(const struct ov2685_mode *mode,
			    struct v4l2_mbus_framefmt *fmt)
{
	fmt->code = MEDIA_BUS_FMT_SBGGR10_1X10;
	fmt->width = mode->width;
	fmt->height = mode->height;
	fmt->field = V4L2_FIELD_NONE;
}

static int ov2685_set_fmt(struct v4l2_subdev *sd,
			  struct v4l2_subdev_state *sd_state,
			  struct v4l2_subdev_format *fmt)
{
	struct ov2685 *ov2685 = to_ov2685(sd);
	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;

	/* only one mode supported for now */
	ov2685_fill_fmt(ov2685->cur_mode, mbus_fmt);

	return 0;
}

static int ov2685_get_fmt(struct v4l2_subdev *sd,
			  struct v4l2_subdev_state *sd_state,
			  struct v4l2_subdev_format *fmt)
{
	struct ov2685 *ov2685 = to_ov2685(sd);
	struct v4l2_mbus_framefmt *mbus_fmt = &fmt->format;

	ov2685_fill_fmt(ov2685->cur_mode, mbus_fmt);

	return 0;
}

static int ov2685_enum_mbus_code(struct v4l2_subdev *sd,
				 struct v4l2_subdev_state *sd_state,
				 struct v4l2_subdev_mbus_code_enum *code)
{
	if (code->index >= ARRAY_SIZE(supported_modes))
		return -EINVAL;

	code->code = MEDIA_BUS_FMT_SBGGR10_1X10;

	return 0;
}

static int ov2685_enum_frame_sizes(struct v4l2_subdev *sd,
				   struct v4l2_subdev_state *sd_state,
				   struct v4l2_subdev_frame_size_enum *fse)
{
	int index = fse->index;

	if (index >= ARRAY_SIZE(supported_modes))
		return -EINVAL;

	fse->code = MEDIA_BUS_FMT_SBGGR10_1X10;

	fse->min_width  = supported_modes[index].width;
	fse->max_width  = supported_modes[index].width;
	fse->max_height = supported_modes[index].height;
	fse->min_height = supported_modes[index].height;

	return 0;
}

static const struct v4l2_rect *
__ov2685_get_pad_crop(struct ov2685 *ov2685,
		      struct v4l2_subdev_state *state, unsigned int pad,
		      enum v4l2_subdev_format_whence which)
{
	const struct ov2685_mode *mode = ov2685->cur_mode;

	switch (which) {
	case V4L2_SUBDEV_FORMAT_TRY:
		return v4l2_subdev_state_get_crop(state, pad);
	case V4L2_SUBDEV_FORMAT_ACTIVE:
		return mode->analog_crop;
	}

	return NULL;
}

static int ov2685_get_selection(struct v4l2_subdev *sd,
				struct v4l2_subdev_state *sd_state,
				struct v4l2_subdev_selection *sel)
{
	struct ov2685 *ov2685 = to_ov2685(sd);

	switch (sel->target) {
	case V4L2_SEL_TGT_CROP:
		mutex_lock(&ov2685->mutex);
		sel->r = *__ov2685_get_pad_crop(ov2685, sd_state, sel->pad,
				sel->which);
		mutex_unlock(&ov2685->mutex);
		break;
	case V4L2_SEL_TGT_NATIVE_SIZE:
	case V4L2_SEL_TGT_CROP_BOUNDS:
		sel->r.top = 0;
		sel->r.left = 0;
		sel->r.width = OV2685_NATIVE_WIDTH;
		sel->r.height = OV2685_NATIVE_HEIGHT;
		break;
	case V4L2_SEL_TGT_CROP_DEFAULT:
		sel->r = ov2685_analog_crop;
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

/* Calculate the delay in us by clock rate and clock cycles */
static inline u32 ov2685_cal_delay(u32 cycles)
{
	return DIV_ROUND_UP(cycles, OV2685_XVCLK_FREQ / 1000 / 1000);
}

static int __ov2685_power_on(struct ov2685 *ov2685)
{
	int ret;
	u32 delay_us;
	struct device *dev = &ov2685->client->dev;

	ret = clk_prepare_enable(ov2685->xvclk);
	if (ret < 0) {
		dev_err(dev, "Failed to enable xvclk\n");
		return ret;
	}

	gpiod_set_value_cansleep(ov2685->reset_gpio, 1);

	ret = regulator_bulk_enable(OV2685_NUM_SUPPLIES, ov2685->supplies);
	if (ret < 0) {
		dev_err(dev, "Failed to enable regulators\n");
		goto disable_clk;
	}

	/* The minimum delay between power supplies and reset rising can be 0 */
	gpiod_set_value_cansleep(ov2685->reset_gpio, 0);
	/* 8192 xvclk cycles prior to the first SCCB transaction */
	delay_us = ov2685_cal_delay(8192);
	usleep_range(delay_us, delay_us * 2);

	/* HACK: ov2685 would output messy data after reset(R0103),
	 * writing register before .s_stream() as a workaround
	 */
	ret = ov2685_write_array(ov2685->client, ov2685->cur_mode->reg_list);
	if (ret) {
		dev_err(dev, "Failed to set regs for power on\n");
		goto disable_supplies;
	}

	return 0;

disable_supplies:
	regulator_bulk_disable(OV2685_NUM_SUPPLIES, ov2685->supplies);
disable_clk:
	clk_disable_unprepare(ov2685->xvclk);

	return ret;
}

static void __ov2685_power_off(struct ov2685 *ov2685)
{
	/* 512 xvclk cycles after the last SCCB transaction or MIPI frame end */
	u32 delay_us = ov2685_cal_delay(512);

	usleep_range(delay_us, delay_us * 2);
	clk_disable_unprepare(ov2685->xvclk);
	gpiod_set_value_cansleep(ov2685->reset_gpio, 1);
	regulator_bulk_disable(OV2685_NUM_SUPPLIES, ov2685->supplies);
}

static int ov2685_s_stream(struct v4l2_subdev *sd, int on)
{
	struct ov2685 *ov2685 = to_ov2685(sd);
	struct i2c_client *client = ov2685->client;
	int ret = 0;

	mutex_lock(&ov2685->mutex);

	if (on) {
		ret = pm_runtime_resume_and_get(&ov2685->client->dev);
		if (ret < 0)
			goto unlock_and_return;

		ret = __v4l2_ctrl_handler_setup(&ov2685->ctrl_handler);
		if (ret) {
			pm_runtime_put(&client->dev);
			goto unlock_and_return;
		}
		ret = ov2685_write_reg(client, REG_SC_CTRL_MODE,
				OV2685_REG_VALUE_08BIT, SC_CTRL_MODE_STREAMING);
		if (ret) {
			pm_runtime_put(&client->dev);
			goto unlock_and_return;
		}
	} else {
		ov2685_write_reg(client, REG_SC_CTRL_MODE,
				OV2685_REG_VALUE_08BIT, SC_CTRL_MODE_STANDBY);
		pm_runtime_put(&ov2685->client->dev);
	}

unlock_and_return:
	mutex_unlock(&ov2685->mutex);

	return ret;
}

static int ov2685_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
	struct ov2685 *ov2685 = to_ov2685(sd);
	struct v4l2_mbus_framefmt *try_fmt;

	mutex_lock(&ov2685->mutex);

	try_fmt = v4l2_subdev_state_get_format(fh->state, 0);
	/* Initialize try_fmt */
	ov2685_fill_fmt(&supported_modes[0], try_fmt);

	mutex_unlock(&ov2685->mutex);

	return 0;
}

static int __maybe_unused ov2685_runtime_resume(struct device *dev)
{
	struct v4l2_subdev *sd = dev_get_drvdata(dev);
	struct ov2685 *ov2685 = to_ov2685(sd);

	return __ov2685_power_on(ov2685);
}

static int __maybe_unused ov2685_runtime_suspend(struct device *dev)
{
	struct v4l2_subdev *sd = dev_get_drvdata(dev);
	struct ov2685 *ov2685 = to_ov2685(sd);

	__ov2685_power_off(ov2685);

	return 0;
}

static const struct dev_pm_ops ov2685_pm_ops = {
	SET_RUNTIME_PM_OPS(ov2685_runtime_suspend,
			   ov2685_runtime_resume, NULL)
};

static int ov2685_set_ctrl(struct v4l2_ctrl *ctrl)
{
	struct ov2685 *ov2685 = container_of(ctrl->handler,
					     struct ov2685, ctrl_handler);
	struct i2c_client *client = ov2685->client;
	s64 max_expo;
	int ret;

	/* Propagate change of current control to all related controls */
	switch (ctrl->id) {
	case V4L2_CID_VBLANK:
		/* Update max exposure while meeting expected vblanking */
		max_expo = ov2685->cur_mode->height + ctrl->val - 4;
		__v4l2_ctrl_modify_range(ov2685->exposure,
					 ov2685->exposure->minimum, max_expo,
					 ov2685->exposure->step,
					 ov2685->exposure->default_value);
		break;
	}

	if (!pm_runtime_get_if_in_use(&client->dev))
		return 0;

	switch (ctrl->id) {
	case V4L2_CID_EXPOSURE:
		ret = ov2685_write_reg(ov2685->client, OV2685_REG_EXPOSURE,
				       OV2685_REG_VALUE_24BIT, ctrl->val << 4);
		break;
	case V4L2_CID_ANALOGUE_GAIN:
		ret = ov2685_write_reg(ov2685->client, OV2685_REG_GAIN,
				       OV2685_REG_VALUE_16BIT, ctrl->val);
		break;
	case V4L2_CID_VBLANK:
		ret = ov2685_write_reg(ov2685->client, OV2685_REG_VTS,
				       OV2685_REG_VALUE_16BIT,
				       ctrl->val + ov2685->cur_mode->height);
		break;
	case V4L2_CID_TEST_PATTERN:
		ret = ov2685_write_reg(ov2685->client, OV2685_REG_TEST_PATTERN,
				       OV2685_REG_VALUE_08BIT,
				       ov2685_test_pattern_val[ctrl->val]);
		break;
	default:
		dev_warn(&client->dev, "%s Unhandled id:0x%x, val:0x%x\n",
			 __func__, ctrl->id, ctrl->val);
		ret = -EINVAL;
		break;
	}

	pm_runtime_put(&client->dev);

	return ret;
}

static const struct v4l2_subdev_video_ops ov2685_video_ops = {
	.s_stream = ov2685_s_stream,
};

static const struct v4l2_subdev_pad_ops ov2685_pad_ops = {
	.enum_mbus_code = ov2685_enum_mbus_code,
	.enum_frame_size = ov2685_enum_frame_sizes,
	.get_fmt = ov2685_get_fmt,
	.set_fmt = ov2685_set_fmt,
	.get_selection = ov2685_get_selection,
	.set_selection = ov2685_get_selection,
};

static const struct v4l2_subdev_ops ov2685_subdev_ops = {
	.video	= &ov2685_video_ops,
	.pad	= &ov2685_pad_ops,
};

static const struct v4l2_subdev_internal_ops ov2685_internal_ops = {
	.open = ov2685_open,
};

static const struct v4l2_ctrl_ops ov2685_ctrl_ops = {
	.s_ctrl = ov2685_set_ctrl,
};

static int ov2685_initialize_controls(struct ov2685 *ov2685)
{
	const struct ov2685_mode *mode;
	struct v4l2_ctrl_handler *handler;
	struct v4l2_ctrl *ctrl;
	struct v4l2_fwnode_device_properties props;
	u64 exposure_max;
	u32 pixel_rate, h_blank;
	int ret;

	handler = &ov2685->ctrl_handler;
	mode = ov2685->cur_mode;
	ret = v4l2_ctrl_handler_init(handler, 10);
	if (ret)
		return ret;
	handler->lock = &ov2685->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 = (link_freq_menu_items[0] * 2 * OV2685_LANES) /
		     OV2685_BITS_PER_SAMPLE;
	v4l2_ctrl_new_std(handler, NULL, V4L2_CID_PIXEL_RATE,
			  0, pixel_rate, 1, pixel_rate);

	h_blank = mode->hts_def - mode->width;
	ov2685->hblank = v4l2_ctrl_new_std(handler, NULL, V4L2_CID_HBLANK,
				h_blank, h_blank, 1, h_blank);
	if (ov2685->hblank)
		ov2685->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;

	ov2685->vblank = v4l2_ctrl_new_std(handler, &ov2685_ctrl_ops,
				V4L2_CID_VBLANK, mode->vts_def - mode->height,
				OV2685_VTS_MAX - mode->height, 1,
				mode->vts_def - mode->height);

	exposure_max = mode->vts_def - 4;
	ov2685->exposure = v4l2_ctrl_new_std(handler, &ov2685_ctrl_ops,
				V4L2_CID_EXPOSURE, OV2685_EXPOSURE_MIN,
				exposure_max, OV2685_EXPOSURE_STEP,
				mode->exp_def);

	ov2685->anal_gain = v4l2_ctrl_new_std(handler, &ov2685_ctrl_ops,
				V4L2_CID_ANALOGUE_GAIN, OV2685_GAIN_MIN,
				OV2685_GAIN_MAX, OV2685_GAIN_STEP,
				OV2685_GAIN_DEFAULT);

	ov2685->test_pattern = v4l2_ctrl_new_std_menu_items(handler,
				&ov2685_ctrl_ops, V4L2_CID_TEST_PATTERN,
				ARRAY_SIZE(ov2685_test_pattern_menu) - 1,
				0, 0, ov2685_test_pattern_menu);

	/* set properties from fwnode (e.g. rotation, orientation) */
	ret = v4l2_fwnode_device_parse(&ov2685->client->dev, &props);
	if (ret)
		goto err_free_handler;

	ret = v4l2_ctrl_new_fwnode_properties(handler, &ov2685_ctrl_ops, &props);
	if (ret)
		goto err_free_handler;

	if (handler->error) {
		ret = handler->error;
		dev_err(&ov2685->client->dev,
			"Failed to init controls(%d)\n", ret);
		goto err_free_handler;
	}

	ov2685->subdev.ctrl_handler = handler;

	return 0;

err_free_handler:
	v4l2_ctrl_handler_free(handler);

	return ret;
}

static int ov2685_check_sensor_id(struct ov2685 *ov2685,
				  struct i2c_client *client)
{
	struct device *dev = &ov2685->client->dev;
	int ret;
	u32 id = 0;

	ret = ov2685_read_reg(client, OV2685_REG_CHIP_ID,
			      OV2685_REG_VALUE_16BIT, &id);
	if (id != CHIP_ID) {
		dev_err(dev, "Unexpected sensor id(%04x), ret(%d)\n", id, ret);
		return ret;
	}

	dev_info(dev, "Detected OV%04x sensor\n", CHIP_ID);

	return 0;
}

static int ov2685_configure_regulators(struct ov2685 *ov2685)
{
	int i;

	for (i = 0; i < OV2685_NUM_SUPPLIES; i++)
		ov2685->supplies[i].supply = ov2685_supply_names[i];

	return devm_regulator_bulk_get(&ov2685->client->dev,
				       OV2685_NUM_SUPPLIES,
				       ov2685->supplies);
}

static int ov2685_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct ov2685 *ov2685;
	int ret;

	ov2685 = devm_kzalloc(dev, sizeof(*ov2685), GFP_KERNEL);
	if (!ov2685)
		return -ENOMEM;

	ov2685->client = client;
	ov2685->cur_mode = &supported_modes[0];

	ov2685->xvclk = devm_clk_get(dev, "xvclk");
	if (IS_ERR(ov2685->xvclk)) {
		dev_err(dev, "Failed to get xvclk\n");
		return -EINVAL;
	}
	ret = clk_set_rate(ov2685->xvclk, OV2685_XVCLK_FREQ);
	if (ret < 0) {
		dev_err(dev, "Failed to set xvclk rate (24MHz)\n");
		return ret;
	}
	if (clk_get_rate(ov2685->xvclk) != OV2685_XVCLK_FREQ)
		dev_warn(dev, "xvclk mismatched, modes are based on 24MHz\n");

	ov2685->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
	if (IS_ERR(ov2685->reset_gpio)) {
		dev_err(dev, "Failed to get reset-gpios\n");
		return -EINVAL;
	}

	ret = ov2685_configure_regulators(ov2685);
	if (ret) {
		dev_err(dev, "Failed to get power regulators\n");
		return ret;
	}

	mutex_init(&ov2685->mutex);
	v4l2_i2c_subdev_init(&ov2685->subdev, client, &ov2685_subdev_ops);
	ret = ov2685_initialize_controls(ov2685);
	if (ret)
		goto err_destroy_mutex;

	ret = __ov2685_power_on(ov2685);
	if (ret)
		goto err_free_handler;

	ret = ov2685_check_sensor_id(ov2685, client);
	if (ret)
		goto err_power_off;

	ov2685->subdev.internal_ops = &ov2685_internal_ops;
	ov2685->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
	ov2685->pad.flags = MEDIA_PAD_FL_SOURCE;
	ov2685->subdev.entity.function = MEDIA_ENT_F_CAM_SENSOR;
	ret = media_entity_pads_init(&ov2685->subdev.entity, 1, &ov2685->pad);
	if (ret < 0)
		goto err_power_off;

	ret = v4l2_async_register_subdev(&ov2685->subdev);
	if (ret) {
		dev_err(dev, "v4l2 async register subdev failed\n");
		goto err_clean_entity;
	}

	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);
	pm_runtime_idle(dev);

	return 0;

err_clean_entity:
	media_entity_cleanup(&ov2685->subdev.entity);
err_power_off:
	__ov2685_power_off(ov2685);
err_free_handler:
	v4l2_ctrl_handler_free(&ov2685->ctrl_handler);
err_destroy_mutex:
	mutex_destroy(&ov2685->mutex);

	return ret;
}

static void ov2685_remove(struct i2c_client *client)
{
	struct v4l2_subdev *sd = i2c_get_clientdata(client);
	struct ov2685 *ov2685 = to_ov2685(sd);

	v4l2_async_unregister_subdev(sd);
	media_entity_cleanup(&sd->entity);
	v4l2_ctrl_handler_free(&ov2685->ctrl_handler);
	mutex_destroy(&ov2685->mutex);

	pm_runtime_disable(&client->dev);
	if (!pm_runtime_status_suspended(&client->dev))
		__ov2685_power_off(ov2685);
	pm_runtime_set_suspended(&client->dev);
}

#if IS_ENABLED(CONFIG_OF)
static const struct of_device_id ov2685_of_match[] = {
	{ .compatible = "ovti,ov2685" },
	{},
};
MODULE_DEVICE_TABLE(of, ov2685_of_match);
#endif

static struct i2c_driver ov2685_i2c_driver = {
	.driver = {
		.name = "ov2685",
		.pm = &ov2685_pm_ops,
		.of_match_table = of_match_ptr(ov2685_of_match),
	},
	.probe		= ov2685_probe,
	.remove		= ov2685_remove,
};

module_i2c_driver(ov2685_i2c_driver);

MODULE_DESCRIPTION("OmniVision ov2685 sensor driver");
MODULE_LICENSE("GPL v2");