/*
 * Omnivision OV9650/OV9652 CMOS Image Sensor driver
 *
 * Copyright (C) 2013, Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
 *
 * Register definitions and initial settings based on a driver written
 * by Vladimir Fonov.
 * Copyright (c) 2010, Vladimir Fonov
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/media.h>
#include <linux/module.h>
#include <linux/ratelimit.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/videodev2.h>

#include <media/media-entity.h>
#include <media/v4l2-async.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-image-sizes.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-mediabus.h>
#include <media/i2c/ov9650.h>

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug level (0-2)");

#define DRIVER_NAME "OV9650"

/*
 * OV9650/OV9652 register definitions
 */
#define REG_GAIN		0x00	/* Gain control, AGC[7:0] */
#define REG_BLUE		0x01	/* AWB - Blue chanel gain */
#define REG_RED			0x02	/* AWB - Red chanel gain */
#define REG_VREF		0x03	/* [7:6] - AGC[9:8], [5:3]/[2:0] */
#define  VREF_GAIN_MASK		0xc0	/* - VREF end/start low 3 bits */
#define REG_COM1		0x04
#define  COM1_CCIR656		0x40
#define REG_B_AVE		0x05
#define REG_GB_AVE		0x06
#define REG_GR_AVE		0x07
#define REG_R_AVE		0x08
#define REG_COM2		0x09
#define REG_PID			0x0a	/* Product ID MSB */
#define REG_VER			0x0b	/* Product ID LSB */
#define REG_COM3		0x0c
#define  COM3_SWAP		0x40
#define  COM3_VARIOPIXEL1	0x04
#define REG_COM4		0x0d	/* Vario Pixels  */
#define  COM4_VARIOPIXEL2	0x80
#define REG_COM5		0x0e	/* System clock options */
#define  COM5_SLAVE_MODE	0x10
#define  COM5_SYSTEMCLOCK48MHZ	0x80
#define REG_COM6		0x0f	/* HREF & ADBLC options */
#define REG_AECH		0x10	/* Exposure value, AEC[9:2] */
#define REG_CLKRC		0x11	/* Clock control */
#define  CLK_EXT		0x40	/* Use external clock directly */
#define  CLK_SCALE		0x3f	/* Mask for internal clock scale */
#define REG_COM7		0x12	/* SCCB reset, output format */
#define  COM7_RESET		0x80
#define  COM7_FMT_MASK		0x38
#define  COM7_FMT_VGA		0x40
#define	 COM7_FMT_CIF		0x20
#define  COM7_FMT_QVGA		0x10
#define  COM7_FMT_QCIF		0x08
#define	 COM7_RGB		0x04
#define	 COM7_YUV		0x00
#define	 COM7_BAYER		0x01
#define	 COM7_PBAYER		0x05
#define REG_COM8		0x13	/* AGC/AEC options */
#define  COM8_FASTAEC		0x80	/* Enable fast AGC/AEC */
#define  COM8_AECSTEP		0x40	/* Unlimited AEC step size */
#define  COM8_BFILT		0x20	/* Band filter enable */
#define  COM8_AGC		0x04	/* Auto gain enable */
#define  COM8_AWB		0x02	/* White balance enable */
#define  COM8_AEC		0x01	/* Auto exposure enable */
#define REG_COM9		0x14	/* Gain ceiling */
#define  COM9_GAIN_CEIL_MASK	0x70	/* */
#define REG_COM10		0x15	/* PCLK, HREF, HSYNC signals polarity */
#define  COM10_HSYNC		0x40	/* HSYNC instead of HREF */
#define  COM10_PCLK_HB		0x20	/* Suppress PCLK on horiz blank */
#define  COM10_HREF_REV		0x08	/* Reverse HREF */
#define  COM10_VS_LEAD		0x04	/* VSYNC on clock leading edge */
#define  COM10_VS_NEG		0x02	/* VSYNC negative */
#define  COM10_HS_NEG		0x01	/* HSYNC negative */
#define REG_HSTART		0x17	/* Horiz start high bits */
#define REG_HSTOP		0x18	/* Horiz stop high bits */
#define REG_VSTART		0x19	/* Vert start high bits */
#define REG_VSTOP		0x1a	/* Vert stop high bits */
#define REG_PSHFT		0x1b	/* Pixel delay after HREF */
#define REG_MIDH		0x1c	/* Manufacturer ID MSB */
#define REG_MIDL		0x1d	/* Manufufacturer ID LSB */
#define REG_MVFP		0x1e	/* Image mirror/flip */
#define  MVFP_MIRROR		0x20	/* Mirror image */
#define  MVFP_FLIP		0x10	/* Vertical flip */
#define REG_BOS			0x20	/* B channel Offset */
#define REG_GBOS		0x21	/* Gb channel Offset */
#define REG_GROS		0x22	/* Gr channel Offset */
#define REG_ROS			0x23	/* R channel Offset */
#define REG_AEW			0x24	/* AGC upper limit */
#define REG_AEB			0x25	/* AGC lower limit */
#define REG_VPT			0x26	/* AGC/AEC fast mode op region */
#define REG_BBIAS		0x27	/* B channel output bias */
#define REG_GBBIAS		0x28	/* Gb channel output bias */
#define REG_GRCOM		0x29	/* Analog BLC & regulator */
#define REG_EXHCH		0x2a	/* Dummy pixel insert MSB */
#define REG_EXHCL		0x2b	/* Dummy pixel insert LSB */
#define REG_RBIAS		0x2c	/* R channel output bias */
#define REG_ADVFL		0x2d	/* LSB of dummy line insert */
#define REG_ADVFH		0x2e	/* MSB of dummy line insert */
#define REG_YAVE		0x2f	/* Y/G channel average value */
#define REG_HSYST		0x30	/* HSYNC rising edge delay LSB*/
#define REG_HSYEN		0x31	/* HSYNC falling edge delay LSB*/
#define REG_HREF		0x32	/* HREF pieces */
#define REG_CHLF		0x33	/* reserved */
#define REG_ADC			0x37	/* reserved */
#define REG_ACOM		0x38	/* reserved */
#define REG_OFON		0x39	/* Power down register */
#define  OFON_PWRDN		0x08	/* Power down bit */
#define REG_TSLB		0x3a	/* YUVU format */
#define  TSLB_YUYV_MASK		0x0c	/* UYVY or VYUY - see com13 */
#define REG_COM11		0x3b	/* Night mode, banding filter enable */
#define  COM11_NIGHT		0x80	/* Night mode enable */
#define  COM11_NMFR		0x60	/* Two bit NM frame rate */
#define  COM11_BANDING		0x01	/* Banding filter */
#define  COM11_AEC_REF_MASK	0x18	/* AEC reference area selection */
#define REG_COM12		0x3c	/* HREF option, UV average */
#define  COM12_HREF		0x80	/* HREF always */
#define REG_COM13		0x3d	/* Gamma selection, Color matrix en. */
#define  COM13_GAMMA		0x80	/* Gamma enable */
#define	 COM13_UVSAT		0x40	/* UV saturation auto adjustment */
#define  COM13_UVSWAP		0x01	/* V before U - w/TSLB */
#define REG_COM14		0x3e	/* Edge enhancement options */
#define  COM14_EDGE_EN		0x02
#define  COM14_EEF_X2		0x01
#define REG_EDGE		0x3f	/* Edge enhancement factor */
#define  EDGE_FACTOR_MASK	0x0f
#define REG_COM15		0x40	/* Output range, RGB 555/565 */
#define  COM15_R10F0		0x00	/* Data range 10 to F0 */
#define	 COM15_R01FE		0x80	/* 01 to FE */
#define  COM15_R00FF		0xc0	/* 00 to FF */
#define  COM15_RGB565		0x10	/* RGB565 output */
#define  COM15_RGB555		0x30	/* RGB555 output */
#define  COM15_SWAPRB		0x04	/* Swap R&B */
#define REG_COM16		0x41	/* Color matrix coeff options */
#define REG_COM17		0x42	/* Single frame out, banding filter */
/* n = 1...9, 0x4f..0x57 */
#define	REG_MTX(__n)		(0x4f + (__n) - 1)
#define REG_MTXS		0x58
/* Lens Correction Option 1...5, __n = 0...5 */
#define REG_LCC(__n)		(0x62 + (__n) - 1)
#define  LCC5_LCC_ENABLE	0x01	/* LCC5, enable lens correction */
#define  LCC5_LCC_COLOR		0x04
#define REG_MANU		0x67	/* Manual U value */
#define REG_MANV		0x68	/* Manual V value */
#define REG_HV			0x69	/* Manual banding filter MSB */
#define REG_MBD			0x6a	/* Manual banding filter value */
#define REG_DBLV		0x6b	/* reserved */
#define REG_GSP			0x6c	/* Gamma curve */
#define  GSP_LEN		15
#define REG_GST			0x7c	/* Gamma curve */
#define  GST_LEN		15
#define REG_COM21		0x8b
#define REG_COM22		0x8c	/* Edge enhancement, denoising */
#define  COM22_WHTPCOR		0x02	/* White pixel correction enable */
#define  COM22_WHTPCOROPT	0x01	/* White pixel correction option */
#define  COM22_DENOISE		0x10	/* White pixel correction option */
#define REG_COM23		0x8d	/* Color bar test, color gain */
#define  COM23_TEST_MODE	0x10
#define REG_DBLC1		0x8f	/* Digital BLC */
#define REG_DBLC_B		0x90	/* Digital BLC B channel offset */
#define REG_DBLC_R		0x91	/* Digital BLC R channel offset */
#define REG_DM_LNL		0x92	/* Dummy line low 8 bits */
#define REG_DM_LNH		0x93	/* Dummy line high 8 bits */
#define REG_LCCFB		0x9d	/* Lens Correction B channel */
#define REG_LCCFR		0x9e	/* Lens Correction R channel */
#define REG_DBLC_GB		0x9f	/* Digital BLC GB chan offset */
#define REG_DBLC_GR		0xa0	/* Digital BLC GR chan offset */
#define REG_AECHM		0xa1	/* Exposure value - bits AEC[15:10] */
#define REG_BD50ST		0xa2	/* Banding filter value for 50Hz */
#define REG_BD60ST		0xa3	/* Banding filter value for 60Hz */
#define REG_NULL		0xff	/* Array end token */

#define DEF_CLKRC		0x80

#define OV965X_ID(_msb, _lsb)	((_msb) << 8 | (_lsb))
#define OV9650_ID		0x9650
#define OV9652_ID		0x9652

struct ov965x_ctrls {
	struct v4l2_ctrl_handler handler;
	struct {
		struct v4l2_ctrl *auto_exp;
		struct v4l2_ctrl *exposure;
	};
	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 {
		struct v4l2_ctrl *auto_gain;
		struct v4l2_ctrl *gain;
	};
	struct v4l2_ctrl *brightness;
	struct v4l2_ctrl *saturation;
	struct v4l2_ctrl *sharpness;
	struct v4l2_ctrl *light_freq;
	u8 update;
};

struct ov965x_framesize {
	u16 width;
	u16 height;
	u16 max_exp_lines;
	const u8 *regs;
};

struct ov965x_interval {
	struct v4l2_fract interval;
	/* Maximum resolution for this interval */
	struct v4l2_frmsize_discrete size;
	u8 clkrc_div;
};

enum gpio_id {
	GPIO_PWDN,
	GPIO_RST,
	NUM_GPIOS,
};

struct ov965x {
	struct v4l2_subdev sd;
	struct media_pad pad;
	enum v4l2_mbus_type bus_type;
	int gpios[NUM_GPIOS];
	/* External master clock frequency */
	unsigned long mclk_frequency;

	/* Protects the struct fields below */
	struct mutex lock;

	struct i2c_client *client;

	/* Exposure row interval in us */
	unsigned int exp_row_interval;

	unsigned short id;
	const struct ov965x_framesize *frame_size;
	/* YUYV sequence (pixel format) control register */
	u8 tslb_reg;
	struct v4l2_mbus_framefmt format;

	struct ov965x_ctrls ctrls;
	/* Pointer to frame rate control data structure */
	const struct ov965x_interval *fiv;

	int streaming;
	int power;

	u8 apply_frame_fmt;
};

struct i2c_rv {
	u8 addr;
	u8 value;
};

static const struct i2c_rv ov965x_init_regs[] = {
	{ REG_COM2, 0x10 },	/* Set soft sleep mode */
	{ REG_COM5, 0x00 },	/* System clock options */
	{ REG_COM2, 0x01 },	/* Output drive, soft sleep mode */
	{ REG_COM10, 0x00 },	/* Slave mode, HREF vs HSYNC, signals negate */
	{ REG_EDGE, 0xa6 },	/* Edge enhancement treshhold and factor */
	{ REG_COM16, 0x02 },	/* Color matrix coeff double option */
	{ REG_COM17, 0x08 },	/* Single frame out, banding filter */
	{ 0x16, 0x06 },
	{ REG_CHLF, 0xc0 },	/* Reserved  */
	{ 0x34, 0xbf },
	{ 0xa8, 0x80 },
	{ 0x96, 0x04 },
	{ 0x8e, 0x00 },
	{ REG_COM12, 0x77 },	/* HREF option, UV average  */
	{ 0x8b, 0x06 },
	{ 0x35, 0x91 },
	{ 0x94, 0x88 },
	{ 0x95, 0x88 },
	{ REG_COM15, 0xc1 },	/* Output range, RGB 555/565 */
	{ REG_GRCOM, 0x2f },	/* Analog BLC & regulator */
	{ REG_COM6, 0x43 },	/* HREF & ADBLC options */
	{ REG_COM8, 0xe5 },	/* AGC/AEC options */
	{ REG_COM13, 0x90 },	/* Gamma selection, colour matrix, UV delay */
	{ REG_HV, 0x80 },	/* Manual banding filter MSB  */
	{ 0x5c, 0x96 },		/* Reserved up to 0xa5 */
	{ 0x5d, 0x96 },
	{ 0x5e, 0x10 },
	{ 0x59, 0xeb },
	{ 0x5a, 0x9c },
	{ 0x5b, 0x55 },
	{ 0x43, 0xf0 },
	{ 0x44, 0x10 },
	{ 0x45, 0x55 },
	{ 0x46, 0x86 },
	{ 0x47, 0x64 },
	{ 0x48, 0x86 },
	{ 0x5f, 0xe0 },
	{ 0x60, 0x8c },
	{ 0x61, 0x20 },
	{ 0xa5, 0xd9 },
	{ 0xa4, 0x74 },		/* reserved */
	{ REG_COM23, 0x02 },	/* Color gain analog/_digital_ */
	{ REG_COM8, 0xe7 },	/* Enable AEC, AWB, AEC */
	{ REG_COM22, 0x23 },	/* Edge enhancement, denoising */
	{ 0xa9, 0xb8 },
	{ 0xaa, 0x92 },
	{ 0xab, 0x0a },
	{ REG_DBLC1, 0xdf },	/* Digital BLC */
	{ REG_DBLC_B, 0x00 },	/* Digital BLC B chan offset */
	{ REG_DBLC_R, 0x00 },	/* Digital BLC R chan offset */
	{ REG_DBLC_GB, 0x00 },	/* Digital BLC GB chan offset */
	{ REG_DBLC_GR, 0x00 },
	{ REG_COM9, 0x3a },	/* Gain ceiling 16x */
	{ REG_NULL, 0 }
};

#define NUM_FMT_REGS 14
/*
 * COM7,  COM3,  COM4, HSTART, HSTOP, HREF, VSTART, VSTOP, VREF,
 * EXHCH, EXHCL, ADC,  OCOM,   OFON
 */
static const u8 frame_size_reg_addr[NUM_FMT_REGS] = {
	0x12, 0x0c, 0x0d, 0x17, 0x18, 0x32, 0x19, 0x1a, 0x03,
	0x2a, 0x2b, 0x37, 0x38, 0x39,
};

static const u8 ov965x_sxga_regs[NUM_FMT_REGS] = {
	0x00, 0x00, 0x00, 0x1e, 0xbe, 0xbf, 0x01, 0x81, 0x12,
	0x10, 0x34, 0x81, 0x93, 0x51,
};

static const u8 ov965x_vga_regs[NUM_FMT_REGS] = {
	0x40, 0x04, 0x80, 0x26, 0xc6, 0xed, 0x01, 0x3d, 0x00,
	0x10, 0x40, 0x91, 0x12, 0x43,
};

/* Determined empirically. */
static const u8 ov965x_qvga_regs[NUM_FMT_REGS] = {
	0x10, 0x04, 0x80, 0x25, 0xc5, 0xbf, 0x00, 0x80, 0x12,
	0x10, 0x40, 0x91, 0x12, 0x43,
};

static const struct ov965x_framesize ov965x_framesizes[] = {
	{
		.width		= SXGA_WIDTH,
		.height		= SXGA_HEIGHT,
		.regs		= ov965x_sxga_regs,
		.max_exp_lines	= 1048,
	}, {
		.width		= VGA_WIDTH,
		.height		= VGA_HEIGHT,
		.regs		= ov965x_vga_regs,
		.max_exp_lines	= 498,
	}, {
		.width		= QVGA_WIDTH,
		.height		= QVGA_HEIGHT,
		.regs		= ov965x_qvga_regs,
		.max_exp_lines	= 248,
	},
};

struct ov965x_pixfmt {
	u32 code;
	u32 colorspace;
	/* REG_TSLB value, only bits [3:2] may be set. */
	u8 tslb_reg;
};

static const struct ov965x_pixfmt ov965x_formats[] = {
	{ MEDIA_BUS_FMT_YUYV8_2X8, V4L2_COLORSPACE_JPEG, 0x00},
	{ MEDIA_BUS_FMT_YVYU8_2X8, V4L2_COLORSPACE_JPEG, 0x04},
	{ MEDIA_BUS_FMT_UYVY8_2X8, V4L2_COLORSPACE_JPEG, 0x0c},
	{ MEDIA_BUS_FMT_VYUY8_2X8, V4L2_COLORSPACE_JPEG, 0x08},
};

/*
 * This table specifies possible frame resolution and interval
 * combinations. Default CLKRC[5:0] divider values are valid
 * only for 24 MHz external clock frequency.
 */
static struct ov965x_interval ov965x_intervals[] = {
	{{ 100, 625 }, { SXGA_WIDTH, SXGA_HEIGHT }, 0 },  /* 6.25 fps */
	{{ 10,  125 }, { VGA_WIDTH, VGA_HEIGHT },   1 },  /* 12.5 fps */
	{{ 10,  125 }, { QVGA_WIDTH, QVGA_HEIGHT }, 3 },  /* 12.5 fps */
	{{ 1,   25  }, { VGA_WIDTH, VGA_HEIGHT },   0 },  /* 25 fps */
	{{ 1,   25  }, { QVGA_WIDTH, QVGA_HEIGHT }, 1 },  /* 25 fps */
};

static inline struct v4l2_subdev *ctrl_to_sd(struct v4l2_ctrl *ctrl)
{
	return &container_of(ctrl->handler, struct ov965x, ctrls.handler)->sd;
}

static inline struct ov965x *to_ov965x(struct v4l2_subdev *sd)
{
	return container_of(sd, struct ov965x, sd);
}

static int ov965x_read(struct i2c_client *client, u8 addr, u8 *val)
{
	u8 buf = addr;
	struct i2c_msg msg = {
		.addr = client->addr,
		.flags = 0,
		.len = 1,
		.buf = &buf
	};
	int ret;

	ret = i2c_transfer(client->adapter, &msg, 1);
	if (ret == 1) {
		msg.flags = I2C_M_RD;
		ret = i2c_transfer(client->adapter, &msg, 1);

		if (ret == 1)
			*val = buf;
	}

	v4l2_dbg(2, debug, client, "%s: 0x%02x @ 0x%02x. (%d)\n",
		 __func__, *val, addr, ret);

	return ret == 1 ? 0 : ret;
}

static int ov965x_write(struct i2c_client *client, u8 addr, u8 val)
{
	u8 buf[2] = { addr, val };

	int ret = i2c_master_send(client, buf, 2);

	v4l2_dbg(2, debug, client, "%s: 0x%02x @ 0x%02X (%d)\n",
		 __func__, val, addr, ret);

	return ret == 2 ? 0 : ret;
}

static int ov965x_write_array(struct i2c_client *client,
			      const struct i2c_rv *regs)
{
	int i, ret = 0;

	for (i = 0; ret == 0 && regs[i].addr != REG_NULL; i++)
		ret = ov965x_write(client, regs[i].addr, regs[i].value);

	return ret;
}

static int ov965x_set_default_gamma_curve(struct ov965x *ov965x)
{
	static const u8 gamma_curve[] = {
		/* Values taken from OV application note. */
		0x40, 0x30, 0x4b, 0x60, 0x70, 0x70, 0x70, 0x70,
		0x60, 0x60, 0x50, 0x48, 0x3a, 0x2e, 0x28, 0x22,
		0x04, 0x07, 0x10, 0x28,	0x36, 0x44, 0x52, 0x60,
		0x6c, 0x78, 0x8c, 0x9e, 0xbb, 0xd2, 0xe6
	};
	u8 addr = REG_GSP;
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(gamma_curve); i++) {
		int ret = ov965x_write(ov965x->client, addr, gamma_curve[i]);

		if (ret < 0)
			return ret;
		addr++;
	}

	return 0;
};

static int ov965x_set_color_matrix(struct ov965x *ov965x)
{
	static const u8 mtx[] = {
		/* MTX1..MTX9, MTXS */
		0x3a, 0x3d, 0x03, 0x12, 0x26, 0x38, 0x40, 0x40, 0x40, 0x0d
	};
	u8 addr = REG_MTX(1);
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(mtx); i++) {
		int ret = ov965x_write(ov965x->client, addr, mtx[i]);

		if (ret < 0)
			return ret;
		addr++;
	}

	return 0;
}

static void ov965x_gpio_set(int gpio, int val)
{
	if (gpio_is_valid(gpio))
		gpio_set_value(gpio, val);
}

static void __ov965x_set_power(struct ov965x *ov965x, int on)
{
	if (on) {
		ov965x_gpio_set(ov965x->gpios[GPIO_PWDN], 0);
		ov965x_gpio_set(ov965x->gpios[GPIO_RST], 0);
		msleep(25);
	} else {
		ov965x_gpio_set(ov965x->gpios[GPIO_RST], 1);
		ov965x_gpio_set(ov965x->gpios[GPIO_PWDN], 1);
	}

	ov965x->streaming = 0;
}

static int ov965x_s_power(struct v4l2_subdev *sd, int on)
{
	struct ov965x *ov965x = to_ov965x(sd);
	struct i2c_client *client = ov965x->client;
	int ret = 0;

	v4l2_dbg(1, debug, client, "%s: on: %d\n", __func__, on);

	mutex_lock(&ov965x->lock);
	if (ov965x->power == !on) {
		__ov965x_set_power(ov965x, on);
		if (on) {
			ret = ov965x_write_array(client,
						 ov965x_init_regs);
			ov965x->apply_frame_fmt = 1;
			ov965x->ctrls.update = 1;
		}
	}
	if (!ret)
		ov965x->power += on ? 1 : -1;

	WARN_ON(ov965x->power < 0);
	mutex_unlock(&ov965x->lock);
	return ret;
}

/*
 * V4L2 controls
 */

static void ov965x_update_exposure_ctrl(struct ov965x *ov965x)
{
	struct v4l2_ctrl *ctrl = ov965x->ctrls.exposure;
	unsigned long fint, trow;
	int min, max, def;
	u8 clkrc;

	mutex_lock(&ov965x->lock);
	if (WARN_ON(!ctrl || !ov965x->frame_size)) {
		mutex_unlock(&ov965x->lock);
		return;
	}
	clkrc = DEF_CLKRC + ov965x->fiv->clkrc_div;
	/* Calculate internal clock frequency */
	fint = ov965x->mclk_frequency * ((clkrc >> 7) + 1) /
				((2 * ((clkrc & 0x3f) + 1)));
	/* and the row interval (in us). */
	trow = (2 * 1520 * 1000000UL) / fint;
	max = ov965x->frame_size->max_exp_lines * trow;
	ov965x->exp_row_interval = trow;
	mutex_unlock(&ov965x->lock);

	v4l2_dbg(1, debug, &ov965x->sd, "clkrc: %#x, fi: %lu, tr: %lu, %d\n",
		 clkrc, fint, trow, max);

	/* Update exposure time range to match current frame format. */
	min = (trow + 100) / 100;
	max = (max - 100) / 100;
	def = min + (max - min) / 2;

	if (v4l2_ctrl_modify_range(ctrl, min, max, 1, def))
		v4l2_err(&ov965x->sd, "Exposure ctrl range update failed\n");
}

static int ov965x_set_banding_filter(struct ov965x *ov965x, int value)
{
	unsigned long mbd, light_freq;
	int ret;
	u8 reg;

	ret = ov965x_read(ov965x->client, REG_COM8, &reg);
	if (!ret) {
		if (value == V4L2_CID_POWER_LINE_FREQUENCY_DISABLED)
			reg &= ~COM8_BFILT;
		else
			reg |= COM8_BFILT;
		ret = ov965x_write(ov965x->client, REG_COM8, reg);
	}
	if (value == V4L2_CID_POWER_LINE_FREQUENCY_DISABLED)
		return 0;
	if (WARN_ON(!ov965x->fiv))
		return -EINVAL;
	/* Set minimal exposure time for 50/60 HZ lighting */
	if (value == V4L2_CID_POWER_LINE_FREQUENCY_50HZ)
		light_freq = 50;
	else
		light_freq = 60;
	mbd = (1000UL * ov965x->fiv->interval.denominator *
	       ov965x->frame_size->max_exp_lines) /
	       ov965x->fiv->interval.numerator;
	mbd = ((mbd / (light_freq * 2)) + 500) / 1000UL;

	return ov965x_write(ov965x->client, REG_MBD, mbd);
}

static int ov965x_set_white_balance(struct ov965x *ov965x, int awb)
{
	int ret;
	u8 reg;

	ret = ov965x_read(ov965x->client, REG_COM8, &reg);
	if (!ret) {
		reg = awb ? reg | REG_COM8 : reg & ~REG_COM8;
		ret = ov965x_write(ov965x->client, REG_COM8, reg);
	}
	if (!ret && !awb) {
		ret = ov965x_write(ov965x->client, REG_BLUE,
				   ov965x->ctrls.blue_balance->val);
		if (ret < 0)
			return ret;
		ret = ov965x_write(ov965x->client, REG_RED,
				   ov965x->ctrls.red_balance->val);
	}
	return ret;
}

#define NUM_BR_LEVELS	7
#define NUM_BR_REGS	3

static int ov965x_set_brightness(struct ov965x *ov965x, int val)
{
	static const u8 regs[NUM_BR_LEVELS + 1][NUM_BR_REGS] = {
		{ REG_AEW, REG_AEB, REG_VPT },
		{ 0x1c, 0x12, 0x50 }, /* -3 */
		{ 0x3d, 0x30, 0x71 }, /* -2 */
		{ 0x50, 0x44, 0x92 }, /* -1 */
		{ 0x70, 0x64, 0xc3 }, /*  0 */
		{ 0x90, 0x84, 0xd4 }, /* +1 */
		{ 0xc4, 0xbf, 0xf9 }, /* +2 */
		{ 0xd8, 0xd0, 0xfa }, /* +3 */
	};
	int i, ret = 0;

	val += (NUM_BR_LEVELS / 2 + 1);
	if (val > NUM_BR_LEVELS)
		return -EINVAL;

	for (i = 0; i < NUM_BR_REGS && !ret; i++)
		ret = ov965x_write(ov965x->client, regs[0][i],
				   regs[val][i]);
	return ret;
}

static int ov965x_set_gain(struct ov965x *ov965x, int auto_gain)
{
	struct i2c_client *client = ov965x->client;
	struct ov965x_ctrls *ctrls = &ov965x->ctrls;
	int ret = 0;
	u8 reg;
	/*
	 * For manual mode we need to disable AGC first, so
	 * gain value in REG_VREF, REG_GAIN is not overwritten.
	 */
	if (ctrls->auto_gain->is_new) {
		ret = ov965x_read(client, REG_COM8, &reg);
		if (ret < 0)
			return ret;
		if (ctrls->auto_gain->val)
			reg |= COM8_AGC;
		else
			reg &= ~COM8_AGC;
		ret = ov965x_write(client, REG_COM8, reg);
		if (ret < 0)
			return ret;
	}

	if (ctrls->gain->is_new && !auto_gain) {
		unsigned int gain = ctrls->gain->val;
		unsigned int rgain;
		int m;
		/*
		 * Convert gain control value to the sensor's gain
		 * registers (VREF[7:6], GAIN[7:0]) format.
		 */
		for (m = 6; m >= 0; m--)
			if (gain >= (1 << m) * 16)
				break;

		/* Sanity check: don't adjust the gain with a negative value */
		if (m < 0)
			return -EINVAL;

		rgain = (gain - ((1 << m) * 16)) / (1 << m);
		rgain |= (((1 << m) - 1) << 4);

		ret = ov965x_write(client, REG_GAIN, rgain & 0xff);
		if (ret < 0)
			return ret;
		ret = ov965x_read(client, REG_VREF, &reg);
		if (ret < 0)
			return ret;
		reg &= ~VREF_GAIN_MASK;
		reg |= (((rgain >> 8) & 0x3) << 6);
		ret = ov965x_write(client, REG_VREF, reg);
		if (ret < 0)
			return ret;
		/* Return updated control's value to userspace */
		ctrls->gain->val = (1 << m) * (16 + (rgain & 0xf));
	}

	return ret;
}

static int ov965x_set_sharpness(struct ov965x *ov965x, unsigned int value)
{
	u8 com14, edge;
	int ret;

	ret = ov965x_read(ov965x->client, REG_COM14, &com14);
	if (ret < 0)
		return ret;
	ret = ov965x_read(ov965x->client, REG_EDGE, &edge);
	if (ret < 0)
		return ret;
	com14 = value ? com14 | COM14_EDGE_EN : com14 & ~COM14_EDGE_EN;
	value--;
	if (value > 0x0f) {
		com14 |= COM14_EEF_X2;
		value >>= 1;
	} else {
		com14 &= ~COM14_EEF_X2;
	}
	ret = ov965x_write(ov965x->client, REG_COM14, com14);
	if (ret < 0)
		return ret;

	edge &= ~EDGE_FACTOR_MASK;
	edge |= ((u8)value & 0x0f);

	return ov965x_write(ov965x->client, REG_EDGE, edge);
}

static int ov965x_set_exposure(struct ov965x *ov965x, int exp)
{
	struct i2c_client *client = ov965x->client;
	struct ov965x_ctrls *ctrls = &ov965x->ctrls;
	bool auto_exposure = (exp == V4L2_EXPOSURE_AUTO);
	int ret;
	u8 reg;

	if (ctrls->auto_exp->is_new) {
		ret = ov965x_read(client, REG_COM8, &reg);
		if (ret < 0)
			return ret;
		if (auto_exposure)
			reg |= (COM8_AEC | COM8_AGC);
		else
			reg &= ~(COM8_AEC | COM8_AGC);
		ret = ov965x_write(client, REG_COM8, reg);
		if (ret < 0)
			return ret;
	}

	if (!auto_exposure && ctrls->exposure->is_new) {
		unsigned int exposure = (ctrls->exposure->val * 100)
					 / ov965x->exp_row_interval;
		/*
		 * Manual exposure value
		 * [b15:b0] - AECHM (b15:b10), AECH (b9:b2), COM1 (b1:b0)
		 */
		ret = ov965x_write(client, REG_COM1, exposure & 0x3);
		if (!ret)
			ret = ov965x_write(client, REG_AECH,
					   (exposure >> 2) & 0xff);
		if (!ret)
			ret = ov965x_write(client, REG_AECHM,
					   (exposure >> 10) & 0x3f);
		/* Update the value to minimize rounding errors */
		ctrls->exposure->val = ((exposure * ov965x->exp_row_interval)
							+ 50) / 100;
		if (ret < 0)
			return ret;
	}

	v4l2_ctrl_activate(ov965x->ctrls.brightness, !exp);
	return 0;
}

static int ov965x_set_flip(struct ov965x *ov965x)
{
	u8 mvfp = 0;

	if (ov965x->ctrls.hflip->val)
		mvfp |= MVFP_MIRROR;

	if (ov965x->ctrls.vflip->val)
		mvfp |= MVFP_FLIP;

	return ov965x_write(ov965x->client, REG_MVFP, mvfp);
}

#define NUM_SAT_LEVELS	5
#define NUM_SAT_REGS	6

static int ov965x_set_saturation(struct ov965x *ov965x, int val)
{
	static const u8 regs[NUM_SAT_LEVELS][NUM_SAT_REGS] = {
		/* MTX(1)...MTX(6) */
		{ 0x1d, 0x1f, 0x02, 0x09, 0x13, 0x1c }, /* -2 */
		{ 0x2e, 0x31, 0x02, 0x0e, 0x1e, 0x2d }, /* -1 */
		{ 0x3a, 0x3d, 0x03, 0x12, 0x26, 0x38 }, /*  0 */
		{ 0x46, 0x49, 0x04, 0x16, 0x2e, 0x43 }, /* +1 */
		{ 0x57, 0x5c, 0x05, 0x1b, 0x39, 0x54 }, /* +2 */
	};
	u8 addr = REG_MTX(1);
	int i, ret = 0;

	val += (NUM_SAT_LEVELS / 2);
	if (val >= NUM_SAT_LEVELS)
		return -EINVAL;

	for (i = 0; i < NUM_SAT_REGS && !ret; i++)
		ret = ov965x_write(ov965x->client, addr + i, regs[val][i]);

	return ret;
}

static int ov965x_set_test_pattern(struct ov965x *ov965x, int value)
{
	int ret;
	u8 reg;

	ret = ov965x_read(ov965x->client, REG_COM23, &reg);
	if (ret < 0)
		return ret;
	reg = value ? reg | COM23_TEST_MODE : reg & ~COM23_TEST_MODE;
	return ov965x_write(ov965x->client, REG_COM23, reg);
}

static int __g_volatile_ctrl(struct ov965x *ov965x, struct v4l2_ctrl *ctrl)
{
	struct i2c_client *client = ov965x->client;
	unsigned int exposure, gain, m;
	u8 reg0, reg1, reg2;
	int ret;

	if (!ov965x->power)
		return 0;

	switch (ctrl->id) {
	case V4L2_CID_AUTOGAIN:
		if (!ctrl->val)
			return 0;
		ret = ov965x_read(client, REG_GAIN, &reg0);
		if (ret < 0)
			return ret;
		ret = ov965x_read(client, REG_VREF, &reg1);
		if (ret < 0)
			return ret;
		gain = ((reg1 >> 6) << 8) | reg0;
		m = 0x01 << fls(gain >> 4);
		ov965x->ctrls.gain->val = m * (16 + (gain & 0xf));
		break;

	case V4L2_CID_EXPOSURE_AUTO:
		if (ctrl->val == V4L2_EXPOSURE_MANUAL)
			return 0;
		ret = ov965x_read(client, REG_COM1, &reg0);
		if (!ret)
			ret = ov965x_read(client, REG_AECH, &reg1);
		if (!ret)
			ret = ov965x_read(client, REG_AECHM, &reg2);
		if (ret < 0)
			return ret;
		exposure = ((reg2 & 0x3f) << 10) | (reg1 << 2) |
						(reg0 & 0x3);
		ov965x->ctrls.exposure->val = ((exposure *
				ov965x->exp_row_interval) + 50) / 100;
		break;
	}

	return 0;
}

static int ov965x_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
	struct v4l2_subdev *sd = ctrl_to_sd(ctrl);
	struct ov965x *ov965x = to_ov965x(sd);
	int ret;

	v4l2_dbg(1, debug, sd, "g_ctrl: %s\n", ctrl->name);

	mutex_lock(&ov965x->lock);
	ret = __g_volatile_ctrl(ov965x, ctrl);
	mutex_unlock(&ov965x->lock);
	return ret;
}

static int ov965x_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct v4l2_subdev *sd = ctrl_to_sd(ctrl);
	struct ov965x *ov965x = to_ov965x(sd);
	int ret = -EINVAL;

	v4l2_dbg(1, debug, sd, "s_ctrl: %s, value: %d. power: %d\n",
		 ctrl->name, ctrl->val, ov965x->power);

	mutex_lock(&ov965x->lock);
	/*
	 * If the device is not powered up now postpone applying control's
	 * value to the hardware, until it is ready to accept commands.
	 */
	if (ov965x->power == 0) {
		mutex_unlock(&ov965x->lock);
		return 0;
	}

	switch (ctrl->id) {
	case V4L2_CID_AUTO_WHITE_BALANCE:
		ret = ov965x_set_white_balance(ov965x, ctrl->val);
		break;

	case V4L2_CID_BRIGHTNESS:
		ret = ov965x_set_brightness(ov965x, ctrl->val);
		break;

	case V4L2_CID_EXPOSURE_AUTO:
		ret = ov965x_set_exposure(ov965x, ctrl->val);
		break;

	case V4L2_CID_AUTOGAIN:
		ret = ov965x_set_gain(ov965x, ctrl->val);
		break;

	case V4L2_CID_HFLIP:
		ret = ov965x_set_flip(ov965x);
		break;

	case V4L2_CID_POWER_LINE_FREQUENCY:
		ret = ov965x_set_banding_filter(ov965x, ctrl->val);
		break;

	case V4L2_CID_SATURATION:
		ret = ov965x_set_saturation(ov965x, ctrl->val);
		break;

	case V4L2_CID_SHARPNESS:
		ret = ov965x_set_sharpness(ov965x, ctrl->val);
		break;

	case V4L2_CID_TEST_PATTERN:
		ret = ov965x_set_test_pattern(ov965x, ctrl->val);
		break;
	}

	mutex_unlock(&ov965x->lock);
	return ret;
}

static const struct v4l2_ctrl_ops ov965x_ctrl_ops = {
	.g_volatile_ctrl = ov965x_g_volatile_ctrl,
	.s_ctrl	= ov965x_s_ctrl,
};

static const char * const test_pattern_menu[] = {
	"Disabled",
	"Color bars",
	NULL
};

static int ov965x_initialize_controls(struct ov965x *ov965x)
{
	const struct v4l2_ctrl_ops *ops = &ov965x_ctrl_ops;
	struct ov965x_ctrls *ctrls = &ov965x->ctrls;
	struct v4l2_ctrl_handler *hdl = &ctrls->handler;
	int ret;

	ret = v4l2_ctrl_handler_init(hdl, 16);
	if (ret < 0)
		return ret;

	/* Auto/manual white balance */
	ctrls->auto_wb = v4l2_ctrl_new_std(hdl, ops,
					   V4L2_CID_AUTO_WHITE_BALANCE,
					   0, 1, 1, 1);
	ctrls->blue_balance = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_BLUE_BALANCE,
						0, 0xff, 1, 0x80);
	ctrls->red_balance = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_RED_BALANCE,
					       0, 0xff, 1, 0x80);
	/* Auto/manual exposure */
	ctrls->auto_exp =
		v4l2_ctrl_new_std_menu(hdl, ops,
				       V4L2_CID_EXPOSURE_AUTO,
				       V4L2_EXPOSURE_MANUAL, 0,
				       V4L2_EXPOSURE_AUTO);
	/* Exposure time, in 100 us units. min/max is updated dynamically. */
	ctrls->exposure = v4l2_ctrl_new_std(hdl, ops,
					    V4L2_CID_EXPOSURE_ABSOLUTE,
					    2, 1500, 1, 500);
	/* Auto/manual gain */
	ctrls->auto_gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_AUTOGAIN,
					     0, 1, 1, 1);
	ctrls->gain = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_GAIN,
					16, 64 * (16 + 15), 1, 64 * 16);

	ctrls->saturation = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_SATURATION,
					      -2, 2, 1, 0);
	ctrls->brightness = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_BRIGHTNESS,
					      -3, 3, 1, 0);
	ctrls->sharpness = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_SHARPNESS,
					     0, 32, 1, 6);

	ctrls->hflip = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_HFLIP, 0, 1, 1, 0);
	ctrls->vflip = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_VFLIP, 0, 1, 1, 0);

	ctrls->light_freq =
		v4l2_ctrl_new_std_menu(hdl, ops,
				       V4L2_CID_POWER_LINE_FREQUENCY,
				       V4L2_CID_POWER_LINE_FREQUENCY_60HZ, ~0x7,
				       V4L2_CID_POWER_LINE_FREQUENCY_50HZ);

	v4l2_ctrl_new_std_menu_items(hdl, ops, V4L2_CID_TEST_PATTERN,
				     ARRAY_SIZE(test_pattern_menu) - 1, 0, 0,
				     test_pattern_menu);
	if (hdl->error) {
		ret = hdl->error;
		v4l2_ctrl_handler_free(hdl);
		return ret;
	}

	ctrls->gain->flags |= V4L2_CTRL_FLAG_VOLATILE;
	ctrls->exposure->flags |= V4L2_CTRL_FLAG_VOLATILE;

	v4l2_ctrl_auto_cluster(3, &ctrls->auto_wb, 0, false);
	v4l2_ctrl_auto_cluster(2, &ctrls->auto_gain, 0, true);
	v4l2_ctrl_auto_cluster(2, &ctrls->auto_exp, 1, true);
	v4l2_ctrl_cluster(2, &ctrls->hflip);

	ov965x->sd.ctrl_handler = hdl;
	return 0;
}

/*
 * V4L2 subdev video and pad level operations
 */
static void ov965x_get_default_format(struct v4l2_mbus_framefmt *mf)
{
	mf->width = ov965x_framesizes[0].width;
	mf->height = ov965x_framesizes[0].height;
	mf->colorspace = ov965x_formats[0].colorspace;
	mf->code = ov965x_formats[0].code;
	mf->field = V4L2_FIELD_NONE;
}

static int ov965x_enum_mbus_code(struct v4l2_subdev *sd,
				 struct v4l2_subdev_pad_config *cfg,
				 struct v4l2_subdev_mbus_code_enum *code)
{
	if (code->index >= ARRAY_SIZE(ov965x_formats))
		return -EINVAL;

	code->code = ov965x_formats[code->index].code;
	return 0;
}

static int ov965x_enum_frame_sizes(struct v4l2_subdev *sd,
				   struct v4l2_subdev_pad_config *cfg,
				   struct v4l2_subdev_frame_size_enum *fse)
{
	int i = ARRAY_SIZE(ov965x_formats);

	if (fse->index >= ARRAY_SIZE(ov965x_framesizes))
		return -EINVAL;

	while (--i)
		if (fse->code == ov965x_formats[i].code)
			break;

	fse->code = ov965x_formats[i].code;

	fse->min_width  = ov965x_framesizes[fse->index].width;
	fse->max_width  = fse->min_width;
	fse->max_height = ov965x_framesizes[fse->index].height;
	fse->min_height = fse->max_height;

	return 0;
}

static int ov965x_g_frame_interval(struct v4l2_subdev *sd,
				   struct v4l2_subdev_frame_interval *fi)
{
	struct ov965x *ov965x = to_ov965x(sd);

	mutex_lock(&ov965x->lock);
	fi->interval = ov965x->fiv->interval;
	mutex_unlock(&ov965x->lock);

	return 0;
}

static int __ov965x_set_frame_interval(struct ov965x *ov965x,
				       struct v4l2_subdev_frame_interval *fi)
{
	struct v4l2_mbus_framefmt *mbus_fmt = &ov965x->format;
	const struct ov965x_interval *fiv = &ov965x_intervals[0];
	u64 req_int, err, min_err = ~0ULL;
	unsigned int i;

	if (fi->interval.denominator == 0)
		return -EINVAL;

	req_int = (u64)(fi->interval.numerator * 10000) /
		fi->interval.denominator;

	for (i = 0; i < ARRAY_SIZE(ov965x_intervals); i++) {
		const struct ov965x_interval *iv = &ov965x_intervals[i];

		if (mbus_fmt->width != iv->size.width ||
		    mbus_fmt->height != iv->size.height)
			continue;
		err = abs((u64)(iv->interval.numerator * 10000) /
			    iv->interval.denominator - req_int);
		if (err < min_err) {
			fiv = iv;
			min_err = err;
		}
	}
	ov965x->fiv = fiv;

	v4l2_dbg(1, debug, &ov965x->sd, "Changed frame interval to %u us\n",
		 fiv->interval.numerator * 1000000 / fiv->interval.denominator);

	return 0;
}

static int ov965x_s_frame_interval(struct v4l2_subdev *sd,
				   struct v4l2_subdev_frame_interval *fi)
{
	struct ov965x *ov965x = to_ov965x(sd);
	int ret;

	v4l2_dbg(1, debug, sd, "Setting %d/%d frame interval\n",
		 fi->interval.numerator, fi->interval.denominator);

	mutex_lock(&ov965x->lock);
	ret = __ov965x_set_frame_interval(ov965x, fi);
	ov965x->apply_frame_fmt = 1;
	mutex_unlock(&ov965x->lock);
	return ret;
}

static int ov965x_get_fmt(struct v4l2_subdev *sd,
			  struct v4l2_subdev_pad_config *cfg,
			  struct v4l2_subdev_format *fmt)
{
	struct ov965x *ov965x = to_ov965x(sd);
	struct v4l2_mbus_framefmt *mf;

	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
		mf = v4l2_subdev_get_try_format(sd, cfg, 0);
		fmt->format = *mf;
		return 0;
	}

	mutex_lock(&ov965x->lock);
	fmt->format = ov965x->format;
	mutex_unlock(&ov965x->lock);

	return 0;
}

static void __ov965x_try_frame_size(struct v4l2_mbus_framefmt *mf,
				    const struct ov965x_framesize **size)
{
	const struct ov965x_framesize *fsize = &ov965x_framesizes[0],
		*match = NULL;
	int i = ARRAY_SIZE(ov965x_framesizes);
	unsigned int min_err = UINT_MAX;

	while (i--) {
		int err = abs(fsize->width - mf->width)
				+ abs(fsize->height - mf->height);
		if (err < min_err) {
			min_err = err;
			match = fsize;
		}
		fsize++;
	}
	if (!match)
		match = &ov965x_framesizes[0];
	mf->width  = match->width;
	mf->height = match->height;
	if (size)
		*size = match;
}

static int ov965x_set_fmt(struct v4l2_subdev *sd,
			  struct v4l2_subdev_pad_config *cfg,
			  struct v4l2_subdev_format *fmt)
{
	unsigned int index = ARRAY_SIZE(ov965x_formats);
	struct v4l2_mbus_framefmt *mf = &fmt->format;
	struct ov965x *ov965x = to_ov965x(sd);
	const struct ov965x_framesize *size = NULL;
	int ret = 0;

	__ov965x_try_frame_size(mf, &size);

	while (--index)
		if (ov965x_formats[index].code == mf->code)
			break;

	mf->colorspace	= V4L2_COLORSPACE_JPEG;
	mf->code	= ov965x_formats[index].code;
	mf->field	= V4L2_FIELD_NONE;

	mutex_lock(&ov965x->lock);

	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
		if (cfg) {
			mf = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
			*mf = fmt->format;
		}
	} else {
		if (ov965x->streaming) {
			ret = -EBUSY;
		} else {
			ov965x->frame_size = size;
			ov965x->format = fmt->format;
			ov965x->tslb_reg = ov965x_formats[index].tslb_reg;
			ov965x->apply_frame_fmt = 1;
		}
	}

	if (!ret && fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
		struct v4l2_subdev_frame_interval fiv = {
			.interval = { 0, 1 }
		};
		/* Reset to minimum possible frame interval */
		__ov965x_set_frame_interval(ov965x, &fiv);
	}
	mutex_unlock(&ov965x->lock);

	if (!ret)
		ov965x_update_exposure_ctrl(ov965x);

	return ret;
}

static int ov965x_set_frame_size(struct ov965x *ov965x)
{
	int i, ret = 0;

	for (i = 0; ret == 0 && i < NUM_FMT_REGS; i++)
		ret = ov965x_write(ov965x->client, frame_size_reg_addr[i],
				   ov965x->frame_size->regs[i]);
	return ret;
}

static int __ov965x_set_params(struct ov965x *ov965x)
{
	struct i2c_client *client = ov965x->client;
	struct ov965x_ctrls *ctrls = &ov965x->ctrls;
	int ret = 0;
	u8 reg;

	if (ov965x->apply_frame_fmt) {
		reg = DEF_CLKRC + ov965x->fiv->clkrc_div;
		ret = ov965x_write(client, REG_CLKRC, reg);
		if (ret < 0)
			return ret;
		ret = ov965x_set_frame_size(ov965x);
		if (ret < 0)
			return ret;
		ret = ov965x_read(client, REG_TSLB, &reg);
		if (ret < 0)
			return ret;
		reg &= ~TSLB_YUYV_MASK;
		reg |= ov965x->tslb_reg;
		ret = ov965x_write(client, REG_TSLB, reg);
		if (ret < 0)
			return ret;
	}
	ret = ov965x_set_default_gamma_curve(ov965x);
	if (ret < 0)
		return ret;
	ret = ov965x_set_color_matrix(ov965x);
	if (ret < 0)
		return ret;
	/*
	 * Select manual banding filter, the filter will
	 * be enabled further if required.
	 */
	ret = ov965x_read(client, REG_COM11, &reg);
	if (!ret)
		reg |= COM11_BANDING;
	ret = ov965x_write(client, REG_COM11, reg);
	if (ret < 0)
		return ret;
	/*
	 * Banding filter (REG_MBD value) needs to match selected
	 * resolution and frame rate, so it's always updated here.
	 */
	return ov965x_set_banding_filter(ov965x, ctrls->light_freq->val);
}

static int ov965x_s_stream(struct v4l2_subdev *sd, int on)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	struct ov965x *ov965x = to_ov965x(sd);
	struct ov965x_ctrls *ctrls = &ov965x->ctrls;
	int ret = 0;

	v4l2_dbg(1, debug, client, "%s: on: %d\n", __func__, on);

	mutex_lock(&ov965x->lock);
	if (ov965x->streaming == !on) {
		if (on)
			ret = __ov965x_set_params(ov965x);

		if (!ret && ctrls->update) {
			/*
			 * ov965x_s_ctrl callback takes the mutex
			 * so it needs to be released here.
			 */
			mutex_unlock(&ov965x->lock);
			ret = v4l2_ctrl_handler_setup(&ctrls->handler);

			mutex_lock(&ov965x->lock);
			if (!ret)
				ctrls->update = 0;
		}
		if (!ret)
			ret = ov965x_write(client, REG_COM2,
					   on ? 0x01 : 0x11);
	}
	if (!ret)
		ov965x->streaming += on ? 1 : -1;

	WARN_ON(ov965x->streaming < 0);
	mutex_unlock(&ov965x->lock);

	return ret;
}

/*
 * V4L2 subdev internal operations
 */
static int ov965x_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
	struct v4l2_mbus_framefmt *mf =
		v4l2_subdev_get_try_format(sd, fh->pad, 0);

	ov965x_get_default_format(mf);
	return 0;
}

static const struct v4l2_subdev_pad_ops ov965x_pad_ops = {
	.enum_mbus_code = ov965x_enum_mbus_code,
	.enum_frame_size = ov965x_enum_frame_sizes,
	.get_fmt = ov965x_get_fmt,
	.set_fmt = ov965x_set_fmt,
};

static const struct v4l2_subdev_video_ops ov965x_video_ops = {
	.s_stream = ov965x_s_stream,
	.g_frame_interval = ov965x_g_frame_interval,
	.s_frame_interval = ov965x_s_frame_interval,

};

static const struct v4l2_subdev_internal_ops ov965x_sd_internal_ops = {
	.open = ov965x_open,
};

static const struct v4l2_subdev_core_ops ov965x_core_ops = {
	.s_power = ov965x_s_power,
	.log_status = v4l2_ctrl_subdev_log_status,
	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
};

static const struct v4l2_subdev_ops ov965x_subdev_ops = {
	.core = &ov965x_core_ops,
	.pad = &ov965x_pad_ops,
	.video = &ov965x_video_ops,
};

/*
 * Reset and power down GPIOs configuration
 */
static int ov965x_configure_gpios(struct ov965x *ov965x,
				  const struct ov9650_platform_data *pdata)
{
	int ret, i;

	ov965x->gpios[GPIO_PWDN] = pdata->gpio_pwdn;
	ov965x->gpios[GPIO_RST]  = pdata->gpio_reset;

	for (i = 0; i < ARRAY_SIZE(ov965x->gpios); i++) {
		int gpio = ov965x->gpios[i];

		if (!gpio_is_valid(gpio))
			continue;
		ret = devm_gpio_request_one(&ov965x->client->dev, gpio,
					    GPIOF_OUT_INIT_HIGH, "OV965X");
		if (ret < 0)
			return ret;
		v4l2_dbg(1, debug, &ov965x->sd, "set gpio %d to 1\n", gpio);

		gpio_set_value(gpio, 1);
		gpio_export(gpio, 0);
		ov965x->gpios[i] = gpio;
	}

	return 0;
}

static int ov965x_detect_sensor(struct v4l2_subdev *sd)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	struct ov965x *ov965x = to_ov965x(sd);
	u8 pid, ver;
	int ret;

	mutex_lock(&ov965x->lock);
	__ov965x_set_power(ov965x, 1);
	msleep(25);

	/* Check sensor revision */
	ret = ov965x_read(client, REG_PID, &pid);
	if (!ret)
		ret = ov965x_read(client, REG_VER, &ver);

	__ov965x_set_power(ov965x, 0);

	if (!ret) {
		ov965x->id = OV965X_ID(pid, ver);
		if (ov965x->id == OV9650_ID || ov965x->id == OV9652_ID) {
			v4l2_info(sd, "Found OV%04X sensor\n", ov965x->id);
		} else {
			v4l2_err(sd, "Sensor detection failed (%04X, %d)\n",
				 ov965x->id, ret);
			ret = -ENODEV;
		}
	}
	mutex_unlock(&ov965x->lock);

	return ret;
}

static int ov965x_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	const struct ov9650_platform_data *pdata = client->dev.platform_data;
	struct v4l2_subdev *sd;
	struct ov965x *ov965x;
	int ret;

	if (!pdata) {
		dev_err(&client->dev, "platform data not specified\n");
		return -EINVAL;
	}

	if (pdata->mclk_frequency == 0) {
		dev_err(&client->dev, "MCLK frequency not specified\n");
		return -EINVAL;
	}

	ov965x = devm_kzalloc(&client->dev, sizeof(*ov965x), GFP_KERNEL);
	if (!ov965x)
		return -ENOMEM;

	mutex_init(&ov965x->lock);
	ov965x->client = client;
	ov965x->mclk_frequency = pdata->mclk_frequency;

	sd = &ov965x->sd;
	v4l2_i2c_subdev_init(sd, client, &ov965x_subdev_ops);
	strlcpy(sd->name, DRIVER_NAME, sizeof(sd->name));

	sd->internal_ops = &ov965x_sd_internal_ops;
	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
		     V4L2_SUBDEV_FL_HAS_EVENTS;

	ret = ov965x_configure_gpios(ov965x, pdata);
	if (ret < 0)
		goto err_mutex;

	ov965x->pad.flags = MEDIA_PAD_FL_SOURCE;
	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
	ret = media_entity_pads_init(&sd->entity, 1, &ov965x->pad);
	if (ret < 0)
		goto err_mutex;

	ret = ov965x_initialize_controls(ov965x);
	if (ret < 0)
		goto err_me;

	ov965x_get_default_format(&ov965x->format);
	ov965x->frame_size = &ov965x_framesizes[0];
	ov965x->fiv = &ov965x_intervals[0];

	ret = ov965x_detect_sensor(sd);
	if (ret < 0)
		goto err_ctrls;

	/* Update exposure time min/max to match frame format */
	ov965x_update_exposure_ctrl(ov965x);

	ret = v4l2_async_register_subdev(sd);
	if (ret < 0)
		goto err_ctrls;

	return 0;
err_ctrls:
	v4l2_ctrl_handler_free(sd->ctrl_handler);
err_me:
	media_entity_cleanup(&sd->entity);
err_mutex:
	mutex_destroy(&ov965x->lock);
	return ret;
}

static int ov965x_remove(struct i2c_client *client)
{
	struct v4l2_subdev *sd = i2c_get_clientdata(client);
	struct ov965x *ov965x = to_ov965x(sd);

	v4l2_async_unregister_subdev(sd);
	v4l2_ctrl_handler_free(sd->ctrl_handler);
	media_entity_cleanup(&sd->entity);
	mutex_destroy(&ov965x->lock);

	return 0;
}

static const struct i2c_device_id ov965x_id[] = {
	{ "OV9650", 0 },
	{ "OV9652", 0 },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, ov965x_id);

static struct i2c_driver ov965x_i2c_driver = {
	.driver = {
		.name	= DRIVER_NAME,
	},
	.probe		= ov965x_probe,
	.remove		= ov965x_remove,
	.id_table	= ov965x_id,
};

module_i2c_driver(ov965x_i2c_driver);

MODULE_AUTHOR("Sylwester Nawrocki <sylvester.nawrocki@gmail.com>");
MODULE_DESCRIPTION("OV9650/OV9652 CMOS Image Sensor driver");
MODULE_LICENSE("GPL");