// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017 Microchip Corporation.

#include <linux/clk.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/regmap.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/v4l2-image-sizes.h>
#include <media/v4l2-subdev.h>

#define REG_OUTSIZE_LSB 0x34

/* OV7740 register tables */
#define REG_GAIN	0x00	/* Gain lower 8 bits (rest in vref) */
#define REG_BGAIN	0x01	/* blue gain */
#define REG_RGAIN	0x02	/* red gain */
#define REG_GGAIN	0x03	/* green gain */
#define REG_REG04	0x04	/* analog setting, don't change*/
#define REG_BAVG	0x05	/* b channel average */
#define REG_GAVG	0x06	/* g channel average */
#define REG_RAVG	0x07	/* r channel average */

#define REG_REG0C	0x0C	/* filp enable */
#define REG0C_IMG_FLIP		0x80
#define REG0C_IMG_MIRROR	0x40

#define REG_REG0E	0x0E	/* blc line */
#define REG_HAEC	0x0F	/* auto exposure cntrl */
#define REG_AEC		0x10	/* auto exposure cntrl */

#define REG_CLK		0x11	/* Clock control */
#define REG_REG55	0x55	/* Clock PLL DIV/PreDiv */

#define REG_REG12	0x12

#define REG_REG13	0x13	/* auto/manual AGC, AEC, Write Balance*/
#define REG13_AEC_EN	0x01
#define REG13_AGC_EN	0x04

#define REG_REG14	0x14
#define REG_CTRL15	0x15
#define REG15_GAIN_MSB	0x03

#define REG_REG16	0x16

#define REG_MIDH	0x1C	/* manufacture id byte */
#define REG_MIDL	0x1D	/* manufacture id byre */
#define REG_PIDH	0x0A	/* Product ID MSB */
#define REG_PIDL	0x0B	/* Product ID LSB */

#define REG_84		0x84	/* lots of stuff */
#define REG_REG38	0x38	/* sub-addr */

#define REG_AHSTART	0x17	/* Horiz start high bits */
#define REG_AHSIZE	0x18
#define REG_AVSTART	0x19	/* Vert start high bits */
#define REG_AVSIZE	0x1A
#define REG_PSHFT	0x1b	/* Pixel delay after HREF */

#define REG_HOUTSIZE	0x31
#define REG_VOUTSIZE	0x32
#define REG_HVSIZEOFF	0x33
#define REG_REG34	0x34	/* DSP output size H/V LSB*/

#define REG_ISP_CTRL00	0x80
#define ISPCTRL00_AWB_EN	0x10
#define ISPCTRL00_AWB_GAIN_EN	0x04

#define	REG_YGAIN	0xE2	/* ygain for contrast control */

#define	REG_YBRIGHT	  0xE3
#define	REG_SGNSET	  0xE4
#define	SGNSET_YBRIGHT_MASK	  0x08

#define REG_USAT	0xDD
#define REG_VSAT	0xDE


struct ov7740 {
	struct v4l2_subdev subdev;
#if defined(CONFIG_MEDIA_CONTROLLER)
	struct media_pad pad;
#endif
	struct v4l2_mbus_framefmt format;
	const struct ov7740_pixfmt *fmt;  /* Current format */
	const struct ov7740_framesize *frmsize;
	struct regmap *regmap;
	struct clk *xvclk;
	struct v4l2_ctrl_handler ctrl_handler;
	struct {
		/* gain cluster */
		struct v4l2_ctrl *auto_gain;
		struct v4l2_ctrl *gain;
	};
	struct {
		struct v4l2_ctrl *auto_wb;
		struct v4l2_ctrl *blue_balance;
		struct v4l2_ctrl *red_balance;
	};
	struct {
		struct v4l2_ctrl *hflip;
		struct v4l2_ctrl *vflip;
	};
	struct {
		/* exposure cluster */
		struct v4l2_ctrl *auto_exposure;
		struct v4l2_ctrl *exposure;
	};
	struct {
		/* saturation/hue cluster */
		struct v4l2_ctrl *saturation;
		struct v4l2_ctrl *hue;
	};
	struct v4l2_ctrl *brightness;
	struct v4l2_ctrl *contrast;

	struct mutex mutex;	/* To serialize asynchronus callbacks */
	bool streaming;		/* Streaming on/off */

	struct gpio_desc *resetb_gpio;
	struct gpio_desc *pwdn_gpio;
};

struct ov7740_pixfmt {
	u32 mbus_code;
	enum v4l2_colorspace colorspace;
	const struct reg_sequence *regs;
	u32 reg_num;
};

struct ov7740_framesize {
	u16 width;
	u16 height;
	const struct reg_sequence *regs;
	u32 reg_num;
};

static const struct reg_sequence ov7740_vga[] = {
	{0x55, 0x40},
	{0x11, 0x02},

	{0xd5, 0x10},
	{0x0c, 0x12},
	{0x0d, 0x34},
	{0x17, 0x25},
	{0x18, 0xa0},
	{0x19, 0x03},
	{0x1a, 0xf0},
	{0x1b, 0x89},
	{0x22, 0x03},
	{0x29, 0x18},
	{0x2b, 0xf8},
	{0x2c, 0x01},
	{REG_HOUTSIZE, 0xa0},
	{REG_VOUTSIZE, 0xf0},
	{0x33, 0xc4},
	{REG_OUTSIZE_LSB, 0x0},
	{0x35, 0x05},
	{0x04, 0x60},
	{0x27, 0x80},
	{0x3d, 0x0f},
	{0x3e, 0x80},
	{0x3f, 0x40},
	{0x40, 0x7f},
	{0x41, 0x6a},
	{0x42, 0x29},
	{0x44, 0x22},
	{0x45, 0x41},
	{0x47, 0x02},
	{0x49, 0x64},
	{0x4a, 0xa1},
	{0x4b, 0x40},
	{0x4c, 0x1a},
	{0x4d, 0x50},
	{0x4e, 0x13},
	{0x64, 0x00},
	{0x67, 0x88},
	{0x68, 0x1a},

	{0x14, 0x28},
	{0x24, 0x3c},
	{0x25, 0x30},
	{0x26, 0x72},
	{0x50, 0x97},
	{0x51, 0x1f},
	{0x52, 0x00},
	{0x53, 0x00},
	{0x20, 0x00},
	{0x21, 0xcf},
	{0x50, 0x4b},
	{0x38, 0x14},
	{0xe9, 0x00},
	{0x56, 0x55},
	{0x57, 0xff},
	{0x58, 0xff},
	{0x59, 0xff},
	{0x5f, 0x04},
	{0xec, 0x00},
	{0x13, 0xff},

	{0x81, 0x3f},
	{0x82, 0x32},
	{0x38, 0x11},
	{0x84, 0x70},
	{0x85, 0x00},
	{0x86, 0x03},
	{0x87, 0x01},
	{0x88, 0x05},
	{0x89, 0x30},
	{0x8d, 0x30},
	{0x8f, 0x85},
	{0x93, 0x30},
	{0x95, 0x85},
	{0x99, 0x30},
	{0x9b, 0x85},

	{0x9c, 0x08},
	{0x9d, 0x12},
	{0x9e, 0x23},
	{0x9f, 0x45},
	{0xa0, 0x55},
	{0xa1, 0x64},
	{0xa2, 0x72},
	{0xa3, 0x7f},
	{0xa4, 0x8b},
	{0xa5, 0x95},
	{0xa6, 0xa7},
	{0xa7, 0xb5},
	{0xa8, 0xcb},
	{0xa9, 0xdd},
	{0xaa, 0xec},
	{0xab, 0x1a},

	{0xce, 0x78},
	{0xcf, 0x6e},
	{0xd0, 0x0a},
	{0xd1, 0x0c},
	{0xd2, 0x84},
	{0xd3, 0x90},
	{0xd4, 0x1e},

	{0x5a, 0x24},
	{0x5b, 0x1f},
	{0x5c, 0x88},
	{0x5d, 0x60},

	{0xac, 0x6e},
	{0xbe, 0xff},
	{0xbf, 0x00},

	{0x0f, 0x1d},
	{0x0f, 0x1f},
};

static const struct ov7740_framesize ov7740_framesizes[] = {
	{
		.width		= VGA_WIDTH,
		.height		= VGA_HEIGHT,
		.regs		= ov7740_vga,
		.reg_num	= ARRAY_SIZE(ov7740_vga),
	},
};

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int ov7740_get_register(struct v4l2_subdev *sd,
			       struct v4l2_dbg_register *reg)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
	struct regmap *regmap = ov7740->regmap;
	unsigned int val = 0;
	int ret;

	ret = regmap_read(regmap, reg->reg & 0xff, &val);
	reg->val = val;
	reg->size = 1;

	return ret;
}

static int ov7740_set_register(struct v4l2_subdev *sd,
			       const struct v4l2_dbg_register *reg)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
	struct regmap *regmap = ov7740->regmap;

	regmap_write(regmap, reg->reg & 0xff, reg->val & 0xff);

	return 0;
}
#endif

static int ov7740_set_power(struct ov7740 *ov7740, int on)
{
	int ret;

	if (on) {
		ret = clk_prepare_enable(ov7740->xvclk);
		if (ret)
			return ret;

		if (ov7740->pwdn_gpio)
			gpiod_direction_output(ov7740->pwdn_gpio, 0);

		if (ov7740->resetb_gpio) {
			gpiod_set_value(ov7740->resetb_gpio, 1);
			usleep_range(500, 1000);
			gpiod_set_value(ov7740->resetb_gpio, 0);
			usleep_range(3000, 5000);
		}
	} else {
		clk_disable_unprepare(ov7740->xvclk);

		if (ov7740->pwdn_gpio)
			gpiod_direction_output(ov7740->pwdn_gpio, 0);
	}

	return 0;
}

static const struct v4l2_subdev_core_ops ov7740_subdev_core_ops = {
	.log_status = v4l2_ctrl_subdev_log_status,
#ifdef CONFIG_VIDEO_ADV_DEBUG
	.g_register = ov7740_get_register,
	.s_register = ov7740_set_register,
#endif
	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
};

static int ov7740_set_white_balance(struct ov7740 *ov7740, int awb)
{
	struct regmap *regmap = ov7740->regmap;
	unsigned int value;
	int ret;

	ret = regmap_read(regmap, REG_ISP_CTRL00, &value);
	if (!ret) {
		if (awb)
			value |= (ISPCTRL00_AWB_EN | ISPCTRL00_AWB_GAIN_EN);
		else
			value &= ~(ISPCTRL00_AWB_EN | ISPCTRL00_AWB_GAIN_EN);
		ret = regmap_write(regmap, REG_ISP_CTRL00, value);
		if (ret)
			return ret;
	}

	if (!awb) {
		ret = regmap_write(regmap, REG_BGAIN,
				   ov7740->blue_balance->val);
		if (ret)
			return ret;

		ret = regmap_write(regmap, REG_RGAIN, ov7740->red_balance->val);
		if (ret)
			return ret;
	}

	return 0;
}

static int ov7740_set_saturation(struct regmap *regmap, int value)
{
	int ret;

	ret = regmap_write(regmap, REG_USAT, (unsigned char)value);
	if (ret)
		return ret;

	return regmap_write(regmap, REG_VSAT, (unsigned char)value);
}

static int ov7740_set_gain(struct regmap *regmap, int value)
{
	int ret;

	ret = regmap_write(regmap, REG_GAIN, value & 0xff);
	if (ret)
		return ret;

	ret = regmap_update_bits(regmap, REG_CTRL15,
				 REG15_GAIN_MSB, (value >> 8) & 0x3);
	if (!ret)
		ret = regmap_update_bits(regmap, REG_REG13, REG13_AGC_EN, 0);

	return ret;
}

static int ov7740_set_autogain(struct regmap *regmap, int value)
{
	unsigned int reg;
	int ret;

	ret = regmap_read(regmap, REG_REG13, &reg);
	if (ret)
		return ret;
	if (value)
		reg |= REG13_AGC_EN;
	else
		reg &= ~REG13_AGC_EN;
	return regmap_write(regmap, REG_REG13, reg);
}

static int ov7740_set_brightness(struct regmap *regmap, int value)
{
	/* Turn off AEC/AGC */
	regmap_update_bits(regmap, REG_REG13, REG13_AEC_EN, 0);
	regmap_update_bits(regmap, REG_REG13, REG13_AGC_EN, 0);

	if (value >= 0) {
		regmap_write(regmap, REG_YBRIGHT, (unsigned char)value);
		regmap_update_bits(regmap, REG_SGNSET, SGNSET_YBRIGHT_MASK, 0);
	} else{
		regmap_write(regmap, REG_YBRIGHT, (unsigned char)(-value));
		regmap_update_bits(regmap, REG_SGNSET, SGNSET_YBRIGHT_MASK, 1);
	}

	return 0;
}

static int ov7740_set_contrast(struct regmap *regmap, int value)
{
	return regmap_write(regmap, REG_YGAIN, (unsigned char)value);
}

static int ov7740_get_gain(struct ov7740 *ov7740, struct v4l2_ctrl *ctrl)
{
	struct regmap *regmap = ov7740->regmap;
	unsigned int value0, value1;
	int ret;

	if (!ctrl->val)
		return 0;

	ret = regmap_read(regmap, REG_GAIN, &value0);
	if (ret)
		return ret;
	ret = regmap_read(regmap, REG_CTRL15, &value1);
	if (ret)
		return ret;

	ov7740->gain->val = (value1 << 8) | (value0 & 0xff);

	return 0;
}

static int ov7740_get_exp(struct ov7740 *ov7740, struct v4l2_ctrl *ctrl)
{
	struct regmap *regmap = ov7740->regmap;
	unsigned int value0, value1;
	int ret;

	if (ctrl->val == V4L2_EXPOSURE_MANUAL)
		return 0;

	ret = regmap_read(regmap, REG_AEC, &value0);
	if (ret)
		return ret;
	ret = regmap_read(regmap, REG_HAEC, &value1);
	if (ret)
		return ret;

	ov7740->exposure->val = (value1 << 8) | (value0 & 0xff);

	return 0;
}

static int ov7740_set_exp(struct regmap *regmap, int value)
{
	int ret;

	/* Turn off AEC/AGC */
	ret = regmap_update_bits(regmap, REG_REG13,
				 REG13_AEC_EN | REG13_AGC_EN, 0);
	if (ret)
		return ret;

	ret = regmap_write(regmap, REG_AEC, (unsigned char)value);
	if (ret)
		return ret;

	return regmap_write(regmap, REG_HAEC, (unsigned char)(value >> 8));
}

static int ov7740_set_autoexp(struct regmap *regmap,
			      enum v4l2_exposure_auto_type value)
{
	unsigned int reg;
	int ret;

	ret = regmap_read(regmap, REG_REG13, &reg);
	if (!ret) {
		if (value == V4L2_EXPOSURE_AUTO)
			reg |= (REG13_AEC_EN | REG13_AGC_EN);
		else
			reg &= ~(REG13_AEC_EN | REG13_AGC_EN);
		ret = regmap_write(regmap, REG_REG13, reg);
	}

	return ret;
}


static int ov7740_get_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
	struct ov7740 *ov7740 = container_of(ctrl->handler,
					     struct ov7740, ctrl_handler);
	int ret;

	switch (ctrl->id) {
	case V4L2_CID_AUTOGAIN:
		ret = ov7740_get_gain(ov7740, ctrl);
		break;
	case V4L2_CID_EXPOSURE_AUTO:
		ret = ov7740_get_exp(ov7740, ctrl);
		break;
	default:
		ret = -EINVAL;
		break;
	}
	return ret;
}

static int ov7740_set_ctrl(struct v4l2_ctrl *ctrl)
{
	struct ov7740 *ov7740 = container_of(ctrl->handler,
					     struct ov7740, ctrl_handler);
	struct i2c_client *client = v4l2_get_subdevdata(&ov7740->subdev);
	struct regmap *regmap = ov7740->regmap;
	int ret;
	u8 val;

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

	switch (ctrl->id) {
	case V4L2_CID_AUTO_WHITE_BALANCE:
		ret = ov7740_set_white_balance(ov7740, ctrl->val);
		break;
	case V4L2_CID_SATURATION:
		ret = ov7740_set_saturation(regmap, ctrl->val);
		break;
	case V4L2_CID_BRIGHTNESS:
		ret = ov7740_set_brightness(regmap, ctrl->val);
		break;
	case V4L2_CID_CONTRAST:
		ret = ov7740_set_contrast(regmap, ctrl->val);
		break;
	case V4L2_CID_VFLIP:
		val = ctrl->val ? REG0C_IMG_FLIP : 0x00;
		ret = regmap_update_bits(regmap, REG_REG0C,
					 REG0C_IMG_FLIP, val);
		break;
	case V4L2_CID_HFLIP:
		val = ctrl->val ? REG0C_IMG_MIRROR : 0x00;
		ret = regmap_update_bits(regmap, REG_REG0C,
					 REG0C_IMG_MIRROR, val);
		break;
	case V4L2_CID_AUTOGAIN:
		if (!ctrl->val)
			ret = ov7740_set_gain(regmap, ov7740->gain->val);
		else
			ret = ov7740_set_autogain(regmap, ctrl->val);
		break;

	case V4L2_CID_EXPOSURE_AUTO:
		if (ctrl->val == V4L2_EXPOSURE_MANUAL)
			ret = ov7740_set_exp(regmap, ov7740->exposure->val);
		else
			ret = ov7740_set_autoexp(regmap, ctrl->val);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	pm_runtime_put(&client->dev);

	return ret;
}

static const struct v4l2_ctrl_ops ov7740_ctrl_ops = {
	.g_volatile_ctrl = ov7740_get_volatile_ctrl,
	.s_ctrl = ov7740_set_ctrl,
};

static int ov7740_start_streaming(struct ov7740 *ov7740)
{
	int ret;

	if (ov7740->fmt) {
		ret = regmap_multi_reg_write(ov7740->regmap,
					     ov7740->fmt->regs,
					     ov7740->fmt->reg_num);
		if (ret)
			return ret;
	}

	if (ov7740->frmsize) {
		ret = regmap_multi_reg_write(ov7740->regmap,
					     ov7740->frmsize->regs,
					     ov7740->frmsize->reg_num);
		if (ret)
			return ret;
	}

	return __v4l2_ctrl_handler_setup(ov7740->subdev.ctrl_handler);
}

static int ov7740_set_stream(struct v4l2_subdev *sd, int enable)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	int ret = 0;

	mutex_lock(&ov7740->mutex);
	if (ov7740->streaming == enable) {
		mutex_unlock(&ov7740->mutex);
		return 0;
	}

	if (enable) {
		ret = pm_runtime_get_sync(&client->dev);
		if (ret < 0) {
			pm_runtime_put_noidle(&client->dev);
			goto err_unlock;
		}

		ret = ov7740_start_streaming(ov7740);
		if (ret)
			goto err_rpm_put;
	} else {
		pm_runtime_put(&client->dev);
	}

	ov7740->streaming = enable;

	mutex_unlock(&ov7740->mutex);
	return ret;

err_rpm_put:
	pm_runtime_put(&client->dev);
err_unlock:
	mutex_unlock(&ov7740->mutex);
	return ret;
}

static int ov7740_g_frame_interval(struct v4l2_subdev *sd,
				   struct v4l2_subdev_frame_interval *ival)
{
	struct v4l2_fract *tpf = &ival->interval;


	tpf->numerator = 1;
	tpf->denominator = 60;

	return 0;
}

static int ov7740_s_frame_interval(struct v4l2_subdev *sd,
				   struct v4l2_subdev_frame_interval *ival)
{
	struct v4l2_fract *tpf = &ival->interval;


	tpf->numerator = 1;
	tpf->denominator = 60;

	return 0;
}

static const struct v4l2_subdev_video_ops ov7740_subdev_video_ops = {
	.s_stream = ov7740_set_stream,
	.s_frame_interval = ov7740_s_frame_interval,
	.g_frame_interval = ov7740_g_frame_interval,
};

static const struct reg_sequence ov7740_format_yuyv[] = {
	{0x12, 0x00},
	{0x36, 0x3f},
	{0x80, 0x7f},
	{0x83, 0x01},
};

static const struct reg_sequence ov7740_format_bggr8[] = {
	{0x36, 0x2f},
	{0x80, 0x01},
	{0x83, 0x04},
};

static const struct ov7740_pixfmt ov7740_formats[] = {
	{
		.mbus_code = MEDIA_BUS_FMT_YUYV8_2X8,
		.colorspace = V4L2_COLORSPACE_SRGB,
		.regs = ov7740_format_yuyv,
		.reg_num = ARRAY_SIZE(ov7740_format_yuyv),
	},
	{
		.mbus_code = MEDIA_BUS_FMT_SBGGR8_1X8,
		.colorspace = V4L2_COLORSPACE_SRGB,
		.regs = ov7740_format_bggr8,
		.reg_num = ARRAY_SIZE(ov7740_format_bggr8),
	}
};
#define N_OV7740_FMTS ARRAY_SIZE(ov7740_formats)

static int ov7740_enum_mbus_code(struct v4l2_subdev *sd,
				 struct v4l2_subdev_pad_config *cfg,
				 struct v4l2_subdev_mbus_code_enum *code)
{
	if (code->pad || code->index >= N_OV7740_FMTS)
		return -EINVAL;

	code->code = ov7740_formats[code->index].mbus_code;

	return 0;
}

static int ov7740_enum_frame_interval(struct v4l2_subdev *sd,
				struct v4l2_subdev_pad_config *cfg,
				struct v4l2_subdev_frame_interval_enum *fie)
{
	if (fie->pad)
		return -EINVAL;

	if (fie->index >= 1)
		return -EINVAL;

	if ((fie->width != VGA_WIDTH) || (fie->height != VGA_HEIGHT))
		return -EINVAL;

	fie->interval.numerator = 1;
	fie->interval.denominator = 60;

	return 0;
}

static int ov7740_enum_frame_size(struct v4l2_subdev *sd,
				  struct v4l2_subdev_pad_config *cfg,
				  struct v4l2_subdev_frame_size_enum *fse)
{
	if (fse->pad)
		return -EINVAL;

	if (fse->index > 0)
		return -EINVAL;

	fse->min_width = fse->max_width = VGA_WIDTH;
	fse->min_height = fse->max_height = VGA_HEIGHT;

	return 0;
}

static int ov7740_try_fmt_internal(struct v4l2_subdev *sd,
				   struct v4l2_mbus_framefmt *fmt,
				   const struct ov7740_pixfmt **ret_fmt,
				   const struct ov7740_framesize **ret_frmsize)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
	const struct ov7740_framesize *fsize = &ov7740_framesizes[0];
	int index, i;

	for (index = 0; index < N_OV7740_FMTS; index++) {
		if (ov7740_formats[index].mbus_code == fmt->code)
			break;
	}
	if (index >= N_OV7740_FMTS) {
		/* default to first format */
		index = 0;
		fmt->code = ov7740_formats[0].mbus_code;
	}
	if (ret_fmt != NULL)
		*ret_fmt = ov7740_formats + index;

	for (i = 0; i < ARRAY_SIZE(ov7740_framesizes); i++) {
		if ((fsize->width >= fmt->width) &&
		    (fsize->height >= fmt->height)) {
			fmt->width = fsize->width;
			fmt->height = fsize->height;
			break;
		}

		fsize++;
	}
	if (i >= ARRAY_SIZE(ov7740_framesizes)) {
		fsize = &ov7740_framesizes[0];
		fmt->width = fsize->width;
		fmt->height = fsize->height;
	}
	if (ret_frmsize != NULL)
		*ret_frmsize = fsize;

	fmt->field = V4L2_FIELD_NONE;
	fmt->colorspace = ov7740_formats[index].colorspace;

	ov7740->format = *fmt;

	return 0;
}

static int ov7740_set_fmt(struct v4l2_subdev *sd,
			  struct v4l2_subdev_pad_config *cfg,
			  struct v4l2_subdev_format *format)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
	const struct ov7740_pixfmt *ovfmt;
	const struct ov7740_framesize *fsize;
#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
	struct v4l2_mbus_framefmt *mbus_fmt;
#endif
	int ret;

	mutex_lock(&ov7740->mutex);
	if (format->pad) {
		ret = -EINVAL;
		goto error;
	}

	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
		ret = ov7740_try_fmt_internal(sd, &format->format, NULL, NULL);
		if (ret)
			goto error;
#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
		mbus_fmt = v4l2_subdev_get_try_format(sd, cfg, format->pad);
		*mbus_fmt = format->format;
#endif
		mutex_unlock(&ov7740->mutex);
		return 0;
	}

	ret = ov7740_try_fmt_internal(sd, &format->format, &ovfmt, &fsize);
	if (ret)
		goto error;

	ov7740->fmt = ovfmt;
	ov7740->frmsize = fsize;

	mutex_unlock(&ov7740->mutex);
	return 0;

error:
	mutex_unlock(&ov7740->mutex);
	return ret;
}

static int ov7740_get_fmt(struct v4l2_subdev *sd,
			  struct v4l2_subdev_pad_config *cfg,
			  struct v4l2_subdev_format *format)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
	struct v4l2_mbus_framefmt *mbus_fmt;
#endif
	int ret = 0;

	mutex_lock(&ov7740->mutex);
	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
		mbus_fmt = v4l2_subdev_get_try_format(sd, cfg, 0);
		format->format = *mbus_fmt;
		ret = 0;
#else
		ret = -EINVAL;
#endif
	} else {
		format->format = ov7740->format;
	}
	mutex_unlock(&ov7740->mutex);

	return ret;
}

static const struct v4l2_subdev_pad_ops ov7740_subdev_pad_ops = {
	.enum_frame_interval = ov7740_enum_frame_interval,
	.enum_frame_size = ov7740_enum_frame_size,
	.enum_mbus_code = ov7740_enum_mbus_code,
	.get_fmt = ov7740_get_fmt,
	.set_fmt = ov7740_set_fmt,
};

static const struct v4l2_subdev_ops ov7740_subdev_ops = {
	.core	= &ov7740_subdev_core_ops,
	.video	= &ov7740_subdev_video_ops,
	.pad	= &ov7740_subdev_pad_ops,
};

static void ov7740_get_default_format(struct v4l2_subdev *sd,
				      struct v4l2_mbus_framefmt *format)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);

	format->width = ov7740->frmsize->width;
	format->height = ov7740->frmsize->height;
	format->colorspace = ov7740->fmt->colorspace;
	format->code = ov7740->fmt->mbus_code;
	format->field = V4L2_FIELD_NONE;
}

#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
static int ov7740_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);
	struct v4l2_mbus_framefmt *format =
				v4l2_subdev_get_try_format(sd, fh->pad, 0);

	mutex_lock(&ov7740->mutex);
	ov7740_get_default_format(sd, format);
	mutex_unlock(&ov7740->mutex);

	return 0;
}

static const struct v4l2_subdev_internal_ops ov7740_subdev_internal_ops = {
	.open = ov7740_open,
};
#endif

static int ov7740_probe_dt(struct i2c_client *client,
			   struct ov7740 *ov7740)
{
	ov7740->resetb_gpio = devm_gpiod_get_optional(&client->dev, "reset",
			GPIOD_OUT_HIGH);
	if (IS_ERR(ov7740->resetb_gpio)) {
		dev_info(&client->dev, "can't get %s GPIO\n", "reset");
		return PTR_ERR(ov7740->resetb_gpio);
	}

	ov7740->pwdn_gpio = devm_gpiod_get_optional(&client->dev, "powerdown",
			GPIOD_OUT_LOW);
	if (IS_ERR(ov7740->pwdn_gpio)) {
		dev_info(&client->dev, "can't get %s GPIO\n", "powerdown");
		return PTR_ERR(ov7740->pwdn_gpio);
	}

	return 0;
}

static int ov7740_detect(struct ov7740 *ov7740)
{
	struct regmap *regmap = ov7740->regmap;
	unsigned int midh, midl, pidh, pidl;
	int ret;

	ret = regmap_read(regmap, REG_MIDH, &midh);
	if (ret)
		return ret;
	if (midh != 0x7f)
		return -ENODEV;

	ret = regmap_read(regmap, REG_MIDL, &midl);
	if (ret)
		return ret;
	if (midl != 0xa2)
		return -ENODEV;

	ret = regmap_read(regmap, REG_PIDH, &pidh);
	if (ret)
		return ret;
	if (pidh != 0x77)
		return -ENODEV;

	ret = regmap_read(regmap, REG_PIDL, &pidl);
	if (ret)
		return ret;
	if ((pidl != 0x40) && (pidl != 0x41) && (pidl != 0x42))
		return -ENODEV;

	return 0;
}

static int ov7740_init_controls(struct ov7740 *ov7740)
{
	struct i2c_client *client = v4l2_get_subdevdata(&ov7740->subdev);
	struct v4l2_ctrl_handler *ctrl_hdlr = &ov7740->ctrl_handler;
	int ret;

	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 12);
	if (ret < 0)
		return ret;

	ctrl_hdlr->lock = &ov7740->mutex;
	ov7740->auto_wb = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					  V4L2_CID_AUTO_WHITE_BALANCE,
					  0, 1, 1, 1);
	ov7740->blue_balance = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					       V4L2_CID_BLUE_BALANCE,
					       0, 0xff, 1, 0x80);
	ov7740->red_balance = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					      V4L2_CID_RED_BALANCE,
					      0, 0xff, 1, 0x80);

	ov7740->brightness = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					     V4L2_CID_BRIGHTNESS,
					     -255, 255, 1, 0);
	ov7740->contrast = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					   V4L2_CID_CONTRAST,
					   0, 127, 1, 0x20);
	ov7740->saturation = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
			  V4L2_CID_SATURATION, 0, 256, 1, 0x80);
	ov7740->hflip = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					V4L2_CID_HFLIP, 0, 1, 1, 0);
	ov7740->vflip = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					V4L2_CID_VFLIP, 0, 1, 1, 0);

	ov7740->gain = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
				       V4L2_CID_GAIN, 0, 1023, 1, 500);

	ov7740->auto_gain = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					    V4L2_CID_AUTOGAIN, 0, 1, 1, 1);

	ov7740->exposure = v4l2_ctrl_new_std(ctrl_hdlr, &ov7740_ctrl_ops,
					   V4L2_CID_EXPOSURE, 0, 65535, 1, 500);

	ov7740->auto_exposure = v4l2_ctrl_new_std_menu(ctrl_hdlr,
					&ov7740_ctrl_ops,
					V4L2_CID_EXPOSURE_AUTO,
					V4L2_EXPOSURE_MANUAL, 0,
					V4L2_EXPOSURE_AUTO);

	v4l2_ctrl_auto_cluster(3, &ov7740->auto_wb, 0, false);
	v4l2_ctrl_auto_cluster(2, &ov7740->auto_gain, 0, true);
	v4l2_ctrl_auto_cluster(2, &ov7740->auto_exposure,
			       V4L2_EXPOSURE_MANUAL, true);

	if (ctrl_hdlr->error) {
		ret = ctrl_hdlr->error;
		dev_err(&client->dev, "controls initialisation failed (%d)\n",
			ret);
		goto error;
	}

	ret = v4l2_ctrl_handler_setup(ctrl_hdlr);
	if (ret) {
		dev_err(&client->dev, "%s control init failed (%d)\n",
			__func__, ret);
		goto error;
	}

	ov7740->subdev.ctrl_handler = ctrl_hdlr;
	return 0;

error:
	v4l2_ctrl_handler_free(ctrl_hdlr);
	mutex_destroy(&ov7740->mutex);
	return ret;
}

static void ov7740_free_controls(struct ov7740 *ov7740)
{
	v4l2_ctrl_handler_free(ov7740->subdev.ctrl_handler);
	mutex_destroy(&ov7740->mutex);
}

#define OV7740_MAX_REGISTER     0xff
static const struct regmap_config ov7740_regmap_config = {
	.reg_bits	= 8,
	.val_bits	= 8,
	.max_register	= OV7740_MAX_REGISTER,
};

static int ov7740_probe(struct i2c_client *client)
{
	struct ov7740 *ov7740;
	struct v4l2_subdev *sd;
	int ret;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_BYTE_DATA)) {
		dev_err(&client->dev,
			"OV7740: I2C-Adapter doesn't support SMBUS\n");
		return -EIO;
	}

	ov7740 = devm_kzalloc(&client->dev, sizeof(*ov7740), GFP_KERNEL);
	if (!ov7740)
		return -ENOMEM;

	ov7740->xvclk = devm_clk_get(&client->dev, "xvclk");
	if (IS_ERR(ov7740->xvclk)) {
		ret = PTR_ERR(ov7740->xvclk);
		dev_err(&client->dev,
			"OV7740: fail to get xvclk: %d\n", ret);
		return ret;
	}

	ret = ov7740_probe_dt(client, ov7740);
	if (ret)
		return ret;

	ov7740->regmap = devm_regmap_init_i2c(client, &ov7740_regmap_config);
	if (IS_ERR(ov7740->regmap)) {
		ret = PTR_ERR(ov7740->regmap);
		dev_err(&client->dev, "Failed to allocate register map: %d\n",
			ret);
		return ret;
	}

	sd = &ov7740->subdev;
	client->flags |= I2C_CLIENT_SCCB;
	v4l2_i2c_subdev_init(sd, client, &ov7740_subdev_ops);

#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
	sd->internal_ops = &ov7740_subdev_internal_ops;
	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
#endif

#if defined(CONFIG_MEDIA_CONTROLLER)
	ov7740->pad.flags = MEDIA_PAD_FL_SOURCE;
	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
	ret = media_entity_pads_init(&sd->entity, 1, &ov7740->pad);
	if (ret)
		return ret;
#endif

	ret = ov7740_set_power(ov7740, 1);
	if (ret)
		return ret;

	pm_runtime_set_active(&client->dev);
	pm_runtime_enable(&client->dev);

	ret = ov7740_detect(ov7740);
	if (ret)
		goto error_detect;

	mutex_init(&ov7740->mutex);

	ret = ov7740_init_controls(ov7740);
	if (ret)
		goto error_init_controls;

	v4l_info(client, "chip found @ 0x%02x (%s)\n",
			client->addr << 1, client->adapter->name);

	ov7740->fmt = &ov7740_formats[0];
	ov7740->frmsize = &ov7740_framesizes[0];

	ov7740_get_default_format(sd, &ov7740->format);

	ret = v4l2_async_register_subdev(sd);
	if (ret)
		goto error_async_register;

	pm_runtime_idle(&client->dev);

	return 0;

error_async_register:
	v4l2_ctrl_handler_free(ov7740->subdev.ctrl_handler);
error_init_controls:
	ov7740_free_controls(ov7740);
error_detect:
	pm_runtime_disable(&client->dev);
	pm_runtime_set_suspended(&client->dev);
	ov7740_set_power(ov7740, 0);
	media_entity_cleanup(&ov7740->subdev.entity);

	return ret;
}

static int ov7740_remove(struct i2c_client *client)
{
	struct v4l2_subdev *sd = i2c_get_clientdata(client);
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);

	mutex_destroy(&ov7740->mutex);
	v4l2_ctrl_handler_free(ov7740->subdev.ctrl_handler);
	media_entity_cleanup(&ov7740->subdev.entity);
	v4l2_async_unregister_subdev(sd);
	ov7740_free_controls(ov7740);

	pm_runtime_get_sync(&client->dev);
	pm_runtime_disable(&client->dev);
	pm_runtime_set_suspended(&client->dev);
	pm_runtime_put_noidle(&client->dev);

	ov7740_set_power(ov7740, 0);
	return 0;
}

static int __maybe_unused ov7740_runtime_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct v4l2_subdev *sd = i2c_get_clientdata(client);
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);

	ov7740_set_power(ov7740, 0);

	return 0;
}

static int __maybe_unused ov7740_runtime_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct v4l2_subdev *sd = i2c_get_clientdata(client);
	struct ov7740 *ov7740 = container_of(sd, struct ov7740, subdev);

	return ov7740_set_power(ov7740, 1);
}

static const struct i2c_device_id ov7740_id[] = {
	{ "ov7740", 0 },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, ov7740_id);

static const struct dev_pm_ops ov7740_pm_ops = {
	SET_RUNTIME_PM_OPS(ov7740_runtime_suspend, ov7740_runtime_resume, NULL)
};

static const struct of_device_id ov7740_of_match[] = {
	{.compatible = "ovti,ov7740", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, ov7740_of_match);

static struct i2c_driver ov7740_i2c_driver = {
	.driver = {
		.name = "ov7740",
		.pm = &ov7740_pm_ops,
		.of_match_table = of_match_ptr(ov7740_of_match),
	},
	.probe_new = ov7740_probe,
	.remove   = ov7740_remove,
	.id_table = ov7740_id,
};
module_i2c_driver(ov7740_i2c_driver);

MODULE_DESCRIPTION("The V4L2 driver for Omnivision 7740 sensor");
MODULE_AUTHOR("Songjun Wu <songjun.wu@atmel.com>");
MODULE_LICENSE("GPL v2"