// SPDX-License-Identifier: GPL-2.0
/*
 * ov772x Camera Driver
 *
 * Copyright (C) 2017 Jacopo Mondi <jacopo+renesas@jmondi.org>
 *
 * Copyright (C) 2008 Renesas Solutions Corp.
 * Kuninori Morimoto <morimoto.kuninori@renesas.com>
 *
 * Based on ov7670 and soc_camera_platform driver,
 *
 * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
 * Copyright (C) 2008 Magnus Damm
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/v4l2-mediabus.h>
#include <linux/videodev2.h>

#include <media/i2c/ov772x.h>

#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-image-sizes.h>
#include <media/v4l2-subdev.h>

/*
 * register offset
 */
#define GAIN        0x00 /* AGC - Gain control gain setting */
#define BLUE        0x01 /* AWB - Blue channel gain setting */
#define RED         0x02 /* AWB - Red   channel gain setting */
#define GREEN       0x03 /* AWB - Green channel gain setting */
#define COM1        0x04 /* Common control 1 */
#define BAVG        0x05 /* U/B Average Level */
#define GAVG        0x06 /* Y/Gb Average Level */
#define RAVG        0x07 /* V/R Average Level */
#define AECH        0x08 /* Exposure Value - AEC MSBs */
#define COM2        0x09 /* Common control 2 */
#define PID         0x0A /* Product ID Number MSB */
#define VER         0x0B /* Product ID Number LSB */
#define COM3        0x0C /* Common control 3 */
#define COM4        0x0D /* Common control 4 */
#define COM5        0x0E /* Common control 5 */
#define COM6        0x0F /* Common control 6 */
#define AEC         0x10 /* Exposure Value */
#define CLKRC       0x11 /* Internal clock */
#define COM7        0x12 /* Common control 7 */
#define COM8        0x13 /* Common control 8 */
#define COM9        0x14 /* Common control 9 */
#define COM10       0x15 /* Common control 10 */
#define REG16       0x16 /* Register 16 */
#define HSTART      0x17 /* Horizontal sensor size */
#define HSIZE       0x18 /* Horizontal frame (HREF column) end high 8-bit */
#define VSTART      0x19 /* Vertical frame (row) start high 8-bit */
#define VSIZE       0x1A /* Vertical sensor size */
#define PSHFT       0x1B /* Data format - pixel delay select */
#define MIDH        0x1C /* Manufacturer ID byte - high */
#define MIDL        0x1D /* Manufacturer ID byte - low  */
#define LAEC        0x1F /* Fine AEC value */
#define COM11       0x20 /* Common control 11 */
#define BDBASE      0x22 /* Banding filter Minimum AEC value */
#define DBSTEP      0x23 /* Banding filter Maximum Setp */
#define AEW         0x24 /* AGC/AEC - Stable operating region (upper limit) */
#define AEB         0x25 /* AGC/AEC - Stable operating region (lower limit) */
#define VPT         0x26 /* AGC/AEC Fast mode operating region */
#define REG28       0x28 /* Register 28 */
#define HOUTSIZE    0x29 /* Horizontal data output size MSBs */
#define EXHCH       0x2A /* Dummy pixel insert MSB */
#define EXHCL       0x2B /* Dummy pixel insert LSB */
#define VOUTSIZE    0x2C /* Vertical data output size MSBs */
#define ADVFL       0x2D /* LSB of insert dummy lines in Vertical direction */
#define ADVFH       0x2E /* MSG of insert dummy lines in Vertical direction */
#define YAVE        0x2F /* Y/G Channel Average value */
#define LUMHTH      0x30 /* Histogram AEC/AGC Luminance high level threshold */
#define LUMLTH      0x31 /* Histogram AEC/AGC Luminance low  level threshold */
#define HREF        0x32 /* Image start and size control */
#define DM_LNL      0x33 /* Dummy line low  8 bits */
#define DM_LNH      0x34 /* Dummy line high 8 bits */
#define ADOFF_B     0x35 /* AD offset compensation value for B  channel */
#define ADOFF_R     0x36 /* AD offset compensation value for R  channel */
#define ADOFF_GB    0x37 /* AD offset compensation value for Gb channel */
#define ADOFF_GR    0x38 /* AD offset compensation value for Gr channel */
#define OFF_B       0x39 /* Analog process B  channel offset value */
#define OFF_R       0x3A /* Analog process R  channel offset value */
#define OFF_GB      0x3B /* Analog process Gb channel offset value */
#define OFF_GR      0x3C /* Analog process Gr channel offset value */
#define COM12       0x3D /* Common control 12 */
#define COM13       0x3E /* Common control 13 */
#define COM14       0x3F /* Common control 14 */
#define COM15       0x40 /* Common control 15*/
#define COM16       0x41 /* Common control 16 */
#define TGT_B       0x42 /* BLC blue channel target value */
#define TGT_R       0x43 /* BLC red  channel target value */
#define TGT_GB      0x44 /* BLC Gb   channel target value */
#define TGT_GR      0x45 /* BLC Gr   channel target value */
/* for ov7720 */
#define LCC0        0x46 /* Lens correction control 0 */
#define LCC1        0x47 /* Lens correction option 1 - X coordinate */
#define LCC2        0x48 /* Lens correction option 2 - Y coordinate */
#define LCC3        0x49 /* Lens correction option 3 */
#define LCC4        0x4A /* Lens correction option 4 - radius of the circular */
#define LCC5        0x4B /* Lens correction option 5 */
#define LCC6        0x4C /* Lens correction option 6 */
/* for ov7725 */
#define LC_CTR      0x46 /* Lens correction control */
#define LC_XC       0x47 /* X coordinate of lens correction center relative */
#define LC_YC       0x48 /* Y coordinate of lens correction center relative */
#define LC_COEF     0x49 /* Lens correction coefficient */
#define LC_RADI     0x4A /* Lens correction radius */
#define LC_COEFB    0x4B /* Lens B channel compensation coefficient */
#define LC_COEFR    0x4C /* Lens R channel compensation coefficient */

#define FIXGAIN     0x4D /* Analog fix gain amplifer */
#define AREF0       0x4E /* Sensor reference control */
#define AREF1       0x4F /* Sensor reference current control */
#define AREF2       0x50 /* Analog reference control */
#define AREF3       0x51 /* ADC    reference control */
#define AREF4       0x52 /* ADC    reference control */
#define AREF5       0x53 /* ADC    reference control */
#define AREF6       0x54 /* Analog reference control */
#define AREF7       0x55 /* Analog reference control */
#define UFIX        0x60 /* U channel fixed value output */
#define VFIX        0x61 /* V channel fixed value output */
#define AWBB_BLK    0x62 /* AWB option for advanced AWB */
#define AWB_CTRL0   0x63 /* AWB control byte 0 */
#define DSP_CTRL1   0x64 /* DSP control byte 1 */
#define DSP_CTRL2   0x65 /* DSP control byte 2 */
#define DSP_CTRL3   0x66 /* DSP control byte 3 */
#define DSP_CTRL4   0x67 /* DSP control byte 4 */
#define AWB_BIAS    0x68 /* AWB BLC level clip */
#define AWB_CTRL1   0x69 /* AWB control  1 */
#define AWB_CTRL2   0x6A /* AWB control  2 */
#define AWB_CTRL3   0x6B /* AWB control  3 */
#define AWB_CTRL4   0x6C /* AWB control  4 */
#define AWB_CTRL5   0x6D /* AWB control  5 */
#define AWB_CTRL6   0x6E /* AWB control  6 */
#define AWB_CTRL7   0x6F /* AWB control  7 */
#define AWB_CTRL8   0x70 /* AWB control  8 */
#define AWB_CTRL9   0x71 /* AWB control  9 */
#define AWB_CTRL10  0x72 /* AWB control 10 */
#define AWB_CTRL11  0x73 /* AWB control 11 */
#define AWB_CTRL12  0x74 /* AWB control 12 */
#define AWB_CTRL13  0x75 /* AWB control 13 */
#define AWB_CTRL14  0x76 /* AWB control 14 */
#define AWB_CTRL15  0x77 /* AWB control 15 */
#define AWB_CTRL16  0x78 /* AWB control 16 */
#define AWB_CTRL17  0x79 /* AWB control 17 */
#define AWB_CTRL18  0x7A /* AWB control 18 */
#define AWB_CTRL19  0x7B /* AWB control 19 */
#define AWB_CTRL20  0x7C /* AWB control 20 */
#define AWB_CTRL21  0x7D /* AWB control 21 */
#define GAM1        0x7E /* Gamma Curve  1st segment input end point */
#define GAM2        0x7F /* Gamma Curve  2nd segment input end point */
#define GAM3        0x80 /* Gamma Curve  3rd segment input end point */
#define GAM4        0x81 /* Gamma Curve  4th segment input end point */
#define GAM5        0x82 /* Gamma Curve  5th segment input end point */
#define GAM6        0x83 /* Gamma Curve  6th segment input end point */
#define GAM7        0x84 /* Gamma Curve  7th segment input end point */
#define GAM8        0x85 /* Gamma Curve  8th segment input end point */
#define GAM9        0x86 /* Gamma Curve  9th segment input end point */
#define GAM10       0x87 /* Gamma Curve 10th segment input end point */
#define GAM11       0x88 /* Gamma Curve 11th segment input end point */
#define GAM12       0x89 /* Gamma Curve 12th segment input end point */
#define GAM13       0x8A /* Gamma Curve 13th segment input end point */
#define GAM14       0x8B /* Gamma Curve 14th segment input end point */
#define GAM15       0x8C /* Gamma Curve 15th segment input end point */
#define SLOP        0x8D /* Gamma curve highest segment slope */
#define DNSTH       0x8E /* De-noise threshold */
#define EDGE_STRNGT 0x8F /* Edge strength  control when manual mode */
#define EDGE_TRSHLD 0x90 /* Edge threshold control when manual mode */
#define DNSOFF      0x91 /* Auto De-noise threshold control */
#define EDGE_UPPER  0x92 /* Edge strength upper limit when Auto mode */
#define EDGE_LOWER  0x93 /* Edge strength lower limit when Auto mode */
#define MTX1        0x94 /* Matrix coefficient 1 */
#define MTX2        0x95 /* Matrix coefficient 2 */
#define MTX3        0x96 /* Matrix coefficient 3 */
#define MTX4        0x97 /* Matrix coefficient 4 */
#define MTX5        0x98 /* Matrix coefficient 5 */
#define MTX6        0x99 /* Matrix coefficient 6 */
#define MTX_CTRL    0x9A /* Matrix control */
#define BRIGHT      0x9B /* Brightness control */
#define CNTRST      0x9C /* Contrast contrast */
#define CNTRST_CTRL 0x9D /* Contrast contrast center */
#define UVAD_J0     0x9E /* Auto UV adjust contrast 0 */
#define UVAD_J1     0x9F /* Auto UV adjust contrast 1 */
#define SCAL0       0xA0 /* Scaling control 0 */
#define SCAL1       0xA1 /* Scaling control 1 */
#define SCAL2       0xA2 /* Scaling control 2 */
#define FIFODLYM    0xA3 /* FIFO manual mode delay control */
#define FIFODLYA    0xA4 /* FIFO auto   mode delay control */
#define SDE         0xA6 /* Special digital effect control */
#define USAT        0xA7 /* U component saturation control */
#define VSAT        0xA8 /* V component saturation control */
/* for ov7720 */
#define HUE0        0xA9 /* Hue control 0 */
#define HUE1        0xAA /* Hue control 1 */
/* for ov7725 */
#define HUECOS      0xA9 /* Cosine value */
#define HUESIN      0xAA /* Sine value */

#define SIGN        0xAB /* Sign bit for Hue and contrast */
#define DSPAUTO     0xAC /* DSP auto function ON/OFF control */

/*
 * register detail
 */

/* COM2 */
#define SOFT_SLEEP_MODE 0x10    /* Soft sleep mode */
                                /* Output drive capability */
#define OCAP_1x         0x00    /* 1x */
#define OCAP_2x         0x01    /* 2x */
#define OCAP_3x         0x02    /* 3x */
#define OCAP_4x         0x03    /* 4x */

/* COM3 */
#define SWAP_MASK       (SWAP_RGB | SWAP_YUV | SWAP_ML)
#define IMG_MASK        (VFLIP_IMG | HFLIP_IMG)

#define VFLIP_IMG       0x80    /* Vertical flip image ON/OFF selection */
#define HFLIP_IMG       0x40    /* Horizontal mirror image ON/OFF selection */
#define SWAP_RGB        0x20    /* Swap B/R  output sequence in RGB mode */
#define SWAP_YUV        0x10    /* Swap Y/UV output sequence in YUV mode */
#define SWAP_ML         0x08    /* Swap output MSB/LSB */
                                /* Tri-state option for output clock */
#define NOTRI_CLOCK     0x04    /*   0: Tri-state    at this period */
                                /*   1: No tri-state at this period */
                                /* Tri-state option for output data */
#define NOTRI_DATA      0x02    /*   0: Tri-state    at this period */
                                /*   1: No tri-state at this period */
#define SCOLOR_TEST     0x01    /* Sensor color bar test pattern */

/* COM4 */
                                /* PLL frequency control */
#define PLL_BYPASS      0x00    /*  00: Bypass PLL */
#define PLL_4x          0x40    /*  01: PLL 4x */
#define PLL_6x          0x80    /*  10: PLL 6x */
#define PLL_8x          0xc0    /*  11: PLL 8x */
                                /* AEC evaluate window */
#define AEC_FULL        0x00    /*  00: Full window */
#define AEC_1p2         0x10    /*  01: 1/2  window */
#define AEC_1p4         0x20    /*  10: 1/4  window */
#define AEC_2p3         0x30    /*  11: Low 2/3 window */
#define COM4_RESERVED   0x01    /* Reserved bit */

/* COM5 */
#define AFR_ON_OFF      0x80    /* Auto frame rate control ON/OFF selection */
#define AFR_SPPED       0x40    /* Auto frame rate control speed selection */
                                /* Auto frame rate max rate control */
#define AFR_NO_RATE     0x00    /*     No  reduction of frame rate */
#define AFR_1p2         0x10    /*     Max reduction to 1/2 frame rate */
#define AFR_1p4         0x20    /*     Max reduction to 1/4 frame rate */
#define AFR_1p8         0x30    /* Max reduction to 1/8 frame rate */
                                /* Auto frame rate active point control */
#define AF_2x           0x00    /*     Add frame when AGC reaches  2x gain */
#define AF_4x           0x04    /*     Add frame when AGC reaches  4x gain */
#define AF_8x           0x08    /*     Add frame when AGC reaches  8x gain */
#define AF_16x          0x0c    /* Add frame when AGC reaches 16x gain */
                                /* AEC max step control */
#define AEC_NO_LIMIT    0x01    /*   0 : AEC incease step has limit */
                                /*   1 : No limit to AEC increase step */
/* CLKRC */
                                /* Input clock divider register */
#define CLKRC_RESERVED  0x80    /* Reserved bit */
#define CLKRC_DIV(n)    ((n) - 1)

/* COM7 */
                                /* SCCB Register Reset */
#define SCCB_RESET      0x80    /*   0 : No change */
                                /*   1 : Resets all registers to default */
                                /* Resolution selection */
#define SLCT_MASK       0x40    /*   Mask of VGA or QVGA */
#define SLCT_VGA        0x00    /*   0 : VGA */
#define SLCT_QVGA       0x40    /*   1 : QVGA */
#define ITU656_ON_OFF   0x20    /* ITU656 protocol ON/OFF selection */
#define SENSOR_RAW      0x10    /* Sensor RAW */
                                /* RGB output format control */
#define FMT_MASK        0x0c    /*      Mask of color format */
#define FMT_GBR422      0x00    /*      00 : GBR 4:2:2 */
#define FMT_RGB565      0x04    /*      01 : RGB 565 */
#define FMT_RGB555      0x08    /*      10 : RGB 555 */
#define FMT_RGB444      0x0c    /* 11 : RGB 444 */
                                /* Output format control */
#define OFMT_MASK       0x03    /*      Mask of output format */
#define OFMT_YUV        0x00    /*      00 : YUV */
#define OFMT_P_BRAW     0x01    /*      01 : Processed Bayer RAW */
#define OFMT_RGB        0x02    /*      10 : RGB */
#define OFMT_BRAW       0x03    /* 11 : Bayer RAW */

/* COM8 */
#define FAST_ALGO       0x80    /* Enable fast AGC/AEC algorithm */
                                /* AEC Setp size limit */
#define UNLMT_STEP      0x40    /*   0 : Step size is limited */
                                /*   1 : Unlimited step size */
#define BNDF_ON_OFF     0x20    /* Banding filter ON/OFF */
#define AEC_BND         0x10    /* Enable AEC below banding value */
#define AEC_ON_OFF      0x08    /* Fine AEC ON/OFF control */
#define AGC_ON          0x04    /* AGC Enable */
#define AWB_ON          0x02    /* AWB Enable */
#define AEC_ON          0x01    /* AEC Enable */

/* COM9 */
#define BASE_AECAGC     0x80    /* Histogram or average based AEC/AGC */
                                /* Automatic gain ceiling - maximum AGC value */
#define GAIN_2x         0x00    /*    000 :   2x */
#define GAIN_4x         0x10    /*    001 :   4x */
#define GAIN_8x         0x20    /*    010 :   8x */
#define GAIN_16x        0x30    /*    011 :  16x */
#define GAIN_32x        0x40    /*    100 :  32x */
#define GAIN_64x        0x50    /* 101 :  64x */
#define GAIN_128x       0x60    /* 110 : 128x */
#define DROP_VSYNC      0x04    /* Drop VSYNC output of corrupt frame */
#define DROP_HREF       0x02    /* Drop HREF  output of corrupt frame */

/* COM11 */
#define SGLF_ON_OFF     0x02    /* Single frame ON/OFF selection */
#define SGLF_TRIG       0x01    /* Single frame transfer trigger */

/* HREF */
#define HREF_VSTART_SHIFT       6       /* VSTART LSB */
#define HREF_HSTART_SHIFT       4       /* HSTART 2 LSBs */
#define HREF_VSIZE_SHIFT        2       /* VSIZE LSB */
#define HREF_HSIZE_SHIFT        0       /* HSIZE 2 LSBs */

/* EXHCH */
#define EXHCH_VSIZE_SHIFT       2       /* VOUTSIZE LSB */
#define EXHCH_HSIZE_SHIFT       0       /* HOUTSIZE 2 LSBs */

/* DSP_CTRL1 */
#define FIFO_ON         0x80    /* FIFO enable/disable selection */
#define UV_ON_OFF       0x40    /* UV adjust function ON/OFF selection */
#define YUV444_2_422    0x20    /* YUV444 to 422 UV channel option selection */
#define CLR_MTRX_ON_OFF 0x10    /* Color matrix ON/OFF selection */
#define INTPLT_ON_OFF   0x08    /* Interpolation ON/OFF selection */
#define GMM_ON_OFF      0x04    /* Gamma function ON/OFF selection */
#define AUTO_BLK_ON_OFF 0x02    /* Black defect auto correction ON/OFF */
#define AUTO_WHT_ON_OFF 0x01    /* White define auto correction ON/OFF */

/* DSP_CTRL3 */
#define UV_MASK         0x80    /* UV output sequence option */
#define UV_ON           0x80    /*   ON */
#define UV_OFF          0x00    /*   OFF */
#define CBAR_MASK       0x20    /* DSP Color bar mask */
#define CBAR_ON         0x20    /*   ON */
#define CBAR_OFF        0x00    /*   OFF */

/* DSP_CTRL4 */
#define DSP_OFMT_YUV    0x00
#define DSP_OFMT_RGB    0x00
#define DSP_OFMT_RAW8   0x02
#define DSP_OFMT_RAW10  0x03

/* DSPAUTO (DSP Auto Function ON/OFF Control) */
#define AWB_ACTRL       0x80 /* AWB auto threshold control */
#define DENOISE_ACTRL   0x40 /* De-noise auto threshold control */
#define EDGE_ACTRL      0x20 /* Edge enhancement auto strength control */
#define UV_ACTRL        0x10 /* UV adjust auto slope control */
#define SCAL0_ACTRL     0x08 /* Auto scaling factor control */
#define SCAL1_2_ACTRL   0x04 /* Auto scaling factor control */

#define OV772X_MAX_WIDTH        VGA_WIDTH
#define OV772X_MAX_HEIGHT       VGA_HEIGHT

/*
 * ID
 */
#define OV7720  0x7720
#define OV7725  0x7721
#define VERSION(pid, ver) ((pid << 8) | (ver & 0xFF))

/*
 * PLL multipliers
 */
static struct {
        unsigned int mult;
        u8 com4;
} ov772x_pll[] = {
        { 1, PLL_BYPASS, },
        { 4, PLL_4x, },
        { 6, PLL_6x, },
        { 8, PLL_8x, },
};

/*
 * struct
 */

struct ov772x_color_format {
        u32 code;
        enum v4l2_colorspace colorspace;
        u8 dsp3;
        u8 dsp4;
        u8 com3;
        u8 com7;
};

struct ov772x_win_size {
        char                     *name;
        unsigned char             com7_bit;
        unsigned int              sizeimage;
        struct v4l2_rect          rect;
};

struct ov772x_priv {
        struct v4l2_subdev                subdev;
        struct v4l2_ctrl_handler          hdl;
        struct clk                       *clk;
        struct ov772x_camera_info        *info;
        struct gpio_desc                 *pwdn_gpio;
        struct gpio_desc                 *rstb_gpio;
        const struct ov772x_color_format *cfmt;
        const struct ov772x_win_size     *win;
        unsigned short                    flag_vflip:1;
        unsigned short                    flag_hflip:1;
        /* band_filter = COM8[5] ? 256 - BDBASE : 0 */
        unsigned short                    band_filter;
        unsigned int                      fps;
};

/*
 * supported color format list
 */
static const struct ov772x_color_format ov772x_cfmts[] = {
        {
                .code           = MEDIA_BUS_FMT_YUYV8_2X8,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = 0x0,
                .dsp4           = DSP_OFMT_YUV,
                .com3           = SWAP_YUV,
                .com7           = OFMT_YUV,
        },
        {
                .code           = MEDIA_BUS_FMT_YVYU8_2X8,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = UV_ON,
                .dsp4           = DSP_OFMT_YUV,
                .com3           = SWAP_YUV,
                .com7           = OFMT_YUV,
        },
        {
                .code           = MEDIA_BUS_FMT_UYVY8_2X8,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = 0x0,
                .dsp4           = DSP_OFMT_YUV,
                .com3           = 0x0,
                .com7           = OFMT_YUV,
        },
        {
                .code           = MEDIA_BUS_FMT_RGB555_2X8_PADHI_LE,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = 0x0,
                .dsp4           = DSP_OFMT_YUV,
                .com3           = SWAP_RGB,
                .com7           = FMT_RGB555 | OFMT_RGB,
        },
        {
                .code           = MEDIA_BUS_FMT_RGB555_2X8_PADHI_BE,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = 0x0,
                .dsp4           = DSP_OFMT_YUV,
                .com3           = 0x0,
                .com7           = FMT_RGB555 | OFMT_RGB,
        },
        {
                .code           = MEDIA_BUS_FMT_RGB565_2X8_LE,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = 0x0,
                .dsp4           = DSP_OFMT_YUV,
                .com3           = SWAP_RGB,
                .com7           = FMT_RGB565 | OFMT_RGB,
        },
        {
                .code           = MEDIA_BUS_FMT_RGB565_2X8_BE,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = 0x0,
                .dsp4           = DSP_OFMT_YUV,
                .com3           = 0x0,
                .com7           = FMT_RGB565 | OFMT_RGB,
        },
        {
                /* Setting DSP4 to DSP_OFMT_RAW8 still gives 10-bit output,
                 * regardless of the COM7 value. We can thus only support 10-bit
                 * Bayer until someone figures it out.
                 */
                .code           = MEDIA_BUS_FMT_SBGGR10_1X10,
                .colorspace     = V4L2_COLORSPACE_SRGB,
                .dsp3           = 0x0,
                .dsp4           = DSP_OFMT_RAW10,
                .com3           = 0x0,
                .com7           = SENSOR_RAW | OFMT_BRAW,
        },
};

/*
 * window size list
 */

static const struct ov772x_win_size ov772x_win_sizes[] = {
        {
                .name           = "VGA",
                .com7_bit       = SLCT_VGA,
                .sizeimage      = 510 * 748,
                .rect = {
                        .left   = 140,
                        .top    = 14,
                        .width  = VGA_WIDTH,
                        .height = VGA_HEIGHT,
                },
        }, {
                .name           = "QVGA",
                .com7_bit       = SLCT_QVGA,
                .sizeimage      = 278 * 576,
                .rect = {
                        .left   = 252,
                        .top    = 6,
                        .width  = QVGA_WIDTH,
                        .height = QVGA_HEIGHT,
                },
        },
};

/*
 * frame rate settings lists
 */
static const unsigned int ov772x_frame_intervals[] = { 5, 10, 15, 20, 30, 60 };

/*
 * general function
 */

static struct ov772x_priv *to_ov772x(struct v4l2_subdev *sd)
{
        return container_of(sd, struct ov772x_priv, subdev);
}

static inline int ov772x_read(struct i2c_client *client, u8 addr)
{
        return i2c_smbus_read_byte_data(client, addr);
}

static inline int ov772x_write(struct i2c_client *client, u8 addr, u8 value)
{
        return i2c_smbus_write_byte_data(client, addr, value);
}

static int ov772x_mask_set(struct i2c_client *client, u8  command, u8  mask,
                           u8  set)
{
        s32 val = ov772x_read(client, command);

        if (val < 0)
                return val;

        val &= ~mask;
        val |= set & mask;

        return ov772x_write(client, command, val);
}

static int ov772x_reset(struct i2c_client *client)
{
        int ret;

        ret = ov772x_write(client, COM7, SCCB_RESET);
        if (ret < 0)
                return ret;

        usleep_range(1000, 5000);

        return ov772x_mask_set(client, COM2, SOFT_SLEEP_MODE, SOFT_SLEEP_MODE);
}

/*
 * subdev ops
 */

static int ov772x_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct ov772x_priv *priv = to_ov772x(sd);

        if (!enable) {
                ov772x_mask_set(client, COM2, SOFT_SLEEP_MODE, SOFT_SLEEP_MODE);
                return 0;
        }

        ov772x_mask_set(client, COM2, SOFT_SLEEP_MODE, 0);

        dev_dbg(&client->dev, "format %d, win %s\n",
                priv->cfmt->code, priv->win->name);

        return 0;
}

static int ov772x_set_frame_rate(struct ov772x_priv *priv,
                                 struct v4l2_fract *tpf,
                                 const struct ov772x_color_format *cfmt,
                                 const struct ov772x_win_size *win)
{
        struct i2c_client *client = v4l2_get_subdevdata(&priv->subdev);
        unsigned long fin = clk_get_rate(priv->clk);
        unsigned int fps = tpf->numerator ?
                           tpf->denominator / tpf->numerator :
                           tpf->denominator;
        unsigned int best_diff;
        unsigned int fsize;
        unsigned int pclk;
        unsigned int diff;
        unsigned int idx;
        unsigned int i;
        u8 clkrc = 0;
        u8 com4 = 0;
        int ret;

        /* Approximate to the closest supported frame interval. */
        best_diff = ~0L;
        for (i = 0, idx = 0; i < ARRAY_SIZE(ov772x_frame_intervals); i++) {
                diff = abs(fps - ov772x_frame_intervals[i]);
                if (diff < best_diff) {
                        idx = i;
                        best_diff = diff;
                }
        }
        fps = ov772x_frame_intervals[idx];

        /* Use image size (with blankings) to calculate desired pixel clock. */
        switch (cfmt->com7 & OFMT_MASK) {
        case OFMT_BRAW:
                fsize = win->sizeimage;
                break;
        case OFMT_RGB:
        case OFMT_YUV:
        default:
                fsize = win->sizeimage * 2;
                break;
        }

        pclk = fps * fsize;

        /*
         * Pixel clock generation circuit is pretty simple:
         *
         * Fin -> [ / CLKRC_div] -> [ * PLL_mult] -> pclk
         *
         * Try to approximate the desired pixel clock testing all available
         * PLL multipliers (1x, 4x, 6x, 8x) and calculate corresponding
         * divisor with:
         *
         * div = PLL_mult * Fin / pclk
         *
         * and re-calculate the pixel clock using it:
         *
         * pclk = Fin * PLL_mult / CLKRC_div
         *
         * Choose the PLL_mult and CLKRC_div pair that gives a pixel clock
         * closer to the desired one.
         *
         * The desired pixel clock is calculated using a known frame size
         * (blanking included) and FPS.
         */
        best_diff = ~0L;
        for (i = 0; i < ARRAY_SIZE(ov772x_pll); i++) {
                unsigned int pll_mult = ov772x_pll[i].mult;
                unsigned int pll_out = pll_mult * fin;
                unsigned int t_pclk;
                unsigned int div;

                if (pll_out < pclk)
                        continue;

                div = DIV_ROUND_CLOSEST(pll_out, pclk);
                t_pclk = DIV_ROUND_CLOSEST(fin * pll_mult, div);
                diff = abs(pclk - t_pclk);
                if (diff < best_diff) {
                        best_diff = diff;
                        clkrc = CLKRC_DIV(div);
                        com4 = ov772x_pll[i].com4;
                }
        }

        ret = ov772x_write(client, COM4, com4 | COM4_RESERVED);
        if (ret < 0)
                return ret;

        ret = ov772x_write(client, CLKRC, clkrc | CLKRC_RESERVED);
        if (ret < 0)
                return ret;

        tpf->numerator = 1;
        tpf->denominator = fps;
        priv->fps = tpf->denominator;

        return 0;
}

static int ov772x_g_frame_interval(struct v4l2_subdev *sd,
                                   struct v4l2_subdev_frame_interval *ival)
{
        struct ov772x_priv *priv = to_ov772x(sd);
        struct v4l2_fract *tpf = &ival->interval;

        tpf->numerator = 1;
        tpf->denominator = priv->fps;

        return 0;
}

static int ov772x_s_frame_interval(struct v4l2_subdev *sd,
                                   struct v4l2_subdev_frame_interval *ival)
{
        struct ov772x_priv *priv = to_ov772x(sd);
        struct v4l2_fract *tpf = &ival->interval;

        return ov772x_set_frame_rate(priv, tpf, priv->cfmt, priv->win);
}

static int ov772x_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct ov772x_priv *priv = container_of(ctrl->handler,
                                                struct ov772x_priv, hdl);
        struct v4l2_subdev *sd = &priv->subdev;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret = 0;
        u8 val;

        switch (ctrl->id) {
        case V4L2_CID_VFLIP:
                val = ctrl->val ? VFLIP_IMG : 0x00;
                priv->flag_vflip = ctrl->val;
                if (priv->info->flags & OV772X_FLAG_VFLIP)
                        val ^= VFLIP_IMG;
                return ov772x_mask_set(client, COM3, VFLIP_IMG, val);
        case V4L2_CID_HFLIP:
                val = ctrl->val ? HFLIP_IMG : 0x00;
                priv->flag_hflip = ctrl->val;
                if (priv->info->flags & OV772X_FLAG_HFLIP)
                        val ^= HFLIP_IMG;
                return ov772x_mask_set(client, COM3, HFLIP_IMG, val);
        case V4L2_CID_BAND_STOP_FILTER:
                if (!ctrl->val) {
                        /* Switch the filter off, it is on now */
                        ret = ov772x_mask_set(client, BDBASE, 0xff, 0xff);
                        if (!ret)
                                ret = ov772x_mask_set(client, COM8,
                                                      BNDF_ON_OFF, 0);
                } else {
                        /* Switch the filter on, set AEC low limit */
                        val = 256 - ctrl->val;
                        ret = ov772x_mask_set(client, COM8,
                                              BNDF_ON_OFF, BNDF_ON_OFF);
                        if (!ret)
                                ret = ov772x_mask_set(client, BDBASE,
                                                      0xff, val);
                }
                if (!ret)
                        priv->band_filter = ctrl->val;
                return ret;
        }

        return -EINVAL;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int ov772x_g_register(struct v4l2_subdev *sd,
                             struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int ret;

        reg->size = 1;
        if (reg->reg > 0xff)
                return -EINVAL;

        ret = ov772x_read(client, reg->reg);
        if (ret < 0)
                return ret;

        reg->val = (__u64)ret;

        return 0;
}

static int ov772x_s_register(struct v4l2_subdev *sd,
                             const struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        if (reg->reg > 0xff ||
            reg->val > 0xff)
                return -EINVAL;

        return ov772x_write(client, reg->reg, reg->val);
}
#endif

static int ov772x_power_on(struct ov772x_priv *priv)
{
        struct i2c_client *client = v4l2_get_subdevdata(&priv->subdev);
        int ret;

        if (priv->clk) {
                ret = clk_prepare_enable(priv->clk);
                if (ret)
                        return ret;
        }

        if (priv->pwdn_gpio) {
                gpiod_set_value(priv->pwdn_gpio, 1);
                usleep_range(500, 1000);
        }

        /*
         * FIXME: The reset signal is connected to a shared GPIO on some
         * platforms (namely the SuperH Migo-R). Until a framework becomes
         * available to handle this cleanly, request the GPIO temporarily
         * to avoid conflicts.
         */
        priv->rstb_gpio = gpiod_get_optional(&client->dev, "rstb",
                                             GPIOD_OUT_LOW);
        if (IS_ERR(priv->rstb_gpio)) {
                dev_info(&client->dev, "Unable to get GPIO \"rstb\"");
                return PTR_ERR(priv->rstb_gpio);
        }

        if (priv->rstb_gpio) {
                gpiod_set_value(priv->rstb_gpio, 1);
                usleep_range(500, 1000);
                gpiod_set_value(priv->rstb_gpio, 0);
                usleep_range(500, 1000);

                gpiod_put(priv->rstb_gpio);
        }

        return 0;
}

static int ov772x_power_off(struct ov772x_priv *priv)
{
        clk_disable_unprepare(priv->clk);

        if (priv->pwdn_gpio) {
                gpiod_set_value(priv->pwdn_gpio, 0);
                usleep_range(500, 1000);
        }

        return 0;
}

static int ov772x_s_power(struct v4l2_subdev *sd, int on)
{
        struct ov772x_priv *priv = to_ov772x(sd);

        return on ? ov772x_power_on(priv) :
                    ov772x_power_off(priv);
}

static const struct ov772x_win_size *ov772x_select_win(u32 width, u32 height)
{
        const struct ov772x_win_size *win = &ov772x_win_sizes[0];
        u32 best_diff = UINT_MAX;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(ov772x_win_sizes); ++i) {
                u32 diff = abs(width - ov772x_win_sizes[i].rect.width)
                         + abs(height - ov772x_win_sizes[i].rect.height);
                if (diff < best_diff) {
                        best_diff = diff;
                        win = &ov772x_win_sizes[i];
                }
        }

        return win;
}

static void ov772x_select_params(const struct v4l2_mbus_framefmt *mf,
                                 const struct ov772x_color_format **cfmt,
                                 const struct ov772x_win_size **win)
{
        unsigned int i;

        /* Select a format. */
        *cfmt = &ov772x_cfmts[0];

        for (i = 0; i < ARRAY_SIZE(ov772x_cfmts); i++) {
                if (mf->code == ov772x_cfmts[i].code) {
                        *cfmt = &ov772x_cfmts[i];
                        break;
                }
        }

        /* Select a window size. */
        *win = ov772x_select_win(mf->width, mf->height);
}

static int ov772x_set_params(struct ov772x_priv *priv,
                             const struct ov772x_color_format *cfmt,
                             const struct ov772x_win_size *win)
{
        struct i2c_client *client = v4l2_get_subdevdata(&priv->subdev);
        struct v4l2_fract tpf;
        int ret;
        u8  val;

        /* Reset hardware. */
        ov772x_reset(client);

        /* Edge Ctrl. */
        if (priv->info->edgectrl.strength & OV772X_MANUAL_EDGE_CTRL) {
                /*
                 * Manual Edge Control Mode.
                 *
                 * Edge auto strength bit is set by default.
                 * Remove it when manual mode.
                 */

                ret = ov772x_mask_set(client, DSPAUTO, EDGE_ACTRL, 0x00);
                if (ret < 0)
                        goto ov772x_set_fmt_error;

                ret = ov772x_mask_set(client,
                                      EDGE_TRSHLD, OV772X_EDGE_THRESHOLD_MASK,
                                      priv->info->edgectrl.threshold);
                if (ret < 0)
                        goto ov772x_set_fmt_error;

                ret = ov772x_mask_set(client,
                                      EDGE_STRNGT, OV772X_EDGE_STRENGTH_MASK,
                                      priv->info->edgectrl.strength);
                if (ret < 0)
                        goto ov772x_set_fmt_error;

        } else if (priv->info->edgectrl.upper > priv->info->edgectrl.lower) {
                /*
                 * Auto Edge Control Mode.
                 *
                 * Set upper and lower limit.
                 */
                ret = ov772x_mask_set(client,
                                      EDGE_UPPER, OV772X_EDGE_UPPER_MASK,
                                      priv->info->edgectrl.upper);
                if (ret < 0)
                        goto ov772x_set_fmt_error;

                ret = ov772x_mask_set(client,
                                      EDGE_LOWER, OV772X_EDGE_LOWER_MASK,
                                      priv->info->edgectrl.lower);
                if (ret < 0)
                        goto ov772x_set_fmt_error;
        }

        /* Format and window size. */
        ret = ov772x_write(client, HSTART, win->rect.left >> 2);
        if (ret < 0)
                goto ov772x_set_fmt_error;
        ret = ov772x_write(client, HSIZE, win->rect.width >> 2);
        if (ret < 0)
                goto ov772x_set_fmt_error;
        ret = ov772x_write(client, VSTART, win->rect.top >> 1);
        if (ret < 0)
                goto ov772x_set_fmt_error;
        ret = ov772x_write(client, VSIZE, win->rect.height >> 1);
        if (ret < 0)
                goto ov772x_set_fmt_error;
        ret = ov772x_write(client, HOUTSIZE, win->rect.width >> 2);
        if (ret < 0)
                goto ov772x_set_fmt_error;
        ret = ov772x_write(client, VOUTSIZE, win->rect.height >> 1);
        if (ret < 0)
                goto ov772x_set_fmt_error;
        ret = ov772x_write(client, HREF,
                           ((win->rect.top & 1) << HREF_VSTART_SHIFT) |
                           ((win->rect.left & 3) << HREF_HSTART_SHIFT) |
                           ((win->rect.height & 1) << HREF_VSIZE_SHIFT) |
                           ((win->rect.width & 3) << HREF_HSIZE_SHIFT));
        if (ret < 0)
                goto ov772x_set_fmt_error;
        ret = ov772x_write(client, EXHCH,
                           ((win->rect.height & 1) << EXHCH_VSIZE_SHIFT) |
                           ((win->rect.width & 3) << EXHCH_HSIZE_SHIFT));
        if (ret < 0)
                goto ov772x_set_fmt_error;

        /* Set DSP_CTRL3. */
        val = cfmt->dsp3;
        if (val) {
                ret = ov772x_mask_set(client,
                                      DSP_CTRL3, UV_MASK, val);
                if (ret < 0)
                        goto ov772x_set_fmt_error;
        }

        /* DSP_CTRL4: AEC reference point and DSP output format. */
        if (cfmt->dsp4) {
                ret = ov772x_write(client, DSP_CTRL4, cfmt->dsp4);
                if (ret < 0)
                        goto ov772x_set_fmt_error;
        }

        /* Set COM3. */
        val = cfmt->com3;
        if (priv->info->flags & OV772X_FLAG_VFLIP)
                val |= VFLIP_IMG;
        if (priv->info->flags & OV772X_FLAG_HFLIP)
                val |= HFLIP_IMG;
        if (priv->flag_vflip)
                val ^= VFLIP_IMG;
        if (priv->flag_hflip)
                val ^= HFLIP_IMG;

        ret = ov772x_mask_set(client,
                              COM3, SWAP_MASK | IMG_MASK, val);
        if (ret < 0)
                goto ov772x_set_fmt_error;

        /* COM7: Sensor resolution and output format control. */
        ret = ov772x_write(client, COM7, win->com7_bit | cfmt->com7);
        if (ret < 0)
                goto ov772x_set_fmt_error;

        /* COM4, CLKRC: Set pixel clock and framerate. */
        tpf.numerator = 1;
        tpf.denominator = priv->fps;
        ret = ov772x_set_frame_rate(priv, &tpf, cfmt, win);
        if (ret < 0)
                goto ov772x_set_fmt_error;

        /* Set COM8. */
        if (priv->band_filter) {
                ret = ov772x_mask_set(client, COM8, BNDF_ON_OFF, BNDF_ON_OFF);
                if (!ret)
                        ret = ov772x_mask_set(client, BDBASE,
                                              0xff, 256 - priv->band_filter);
                if (ret < 0)
                        goto ov772x_set_fmt_error;
        }

        return ret;

ov772x_set_fmt_error:

        ov772x_reset(client);

        return ret;
}

static int ov772x_get_selection(struct v4l2_subdev *sd,
                                struct v4l2_subdev_pad_config *cfg,
                                struct v4l2_subdev_selection *sel)
{
        struct ov772x_priv *priv = to_ov772x(sd);

        if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
                return -EINVAL;

        sel->r.left = 0;
        sel->r.top = 0;
        switch (sel->target) {
        case V4L2_SEL_TGT_CROP_BOUNDS:
        case V4L2_SEL_TGT_CROP_DEFAULT:
        case V4L2_SEL_TGT_CROP:
                sel->r.width = priv->win->rect.width;
                sel->r.height = priv->win->rect.height;
                return 0;
        default:
                return -EINVAL;
        }
}

static int ov772x_get_fmt(struct v4l2_subdev *sd,
                          struct v4l2_subdev_pad_config *cfg,
                          struct v4l2_subdev_format *format)
{
        struct v4l2_mbus_framefmt *mf = &format->format;
        struct ov772x_priv *priv = to_ov772x(sd);

        if (format->pad)
                return -EINVAL;

        mf->width       = priv->win->rect.width;
        mf->height      = priv->win->rect.height;
        mf->code        = priv->cfmt->code;
        mf->colorspace  = priv->cfmt->colorspace;
        mf->field       = V4L2_FIELD_NONE;

        return 0;
}

static int ov772x_set_fmt(struct v4l2_subdev *sd,
                          struct v4l2_subdev_pad_config *cfg,
                          struct v4l2_subdev_format *format)
{
        struct ov772x_priv *priv = to_ov772x(sd);
        struct v4l2_mbus_framefmt *mf = &format->format;
        const struct ov772x_color_format *cfmt;
        const struct ov772x_win_size *win;
        int ret;

        if (format->pad)
                return -EINVAL;

        ov772x_select_params(mf, &cfmt, &win);

        mf->code = cfmt->code;
        mf->width = win->rect.width;
        mf->height = win->rect.height;
        mf->field = V4L2_FIELD_NONE;
        mf->colorspace = cfmt->colorspace;
        mf->ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
        mf->quantization = V4L2_QUANTIZATION_DEFAULT;
        mf->xfer_func = V4L2_XFER_FUNC_DEFAULT;

        if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
                cfg->try_fmt = *mf;
                return 0;
        }

        ret = ov772x_set_params(priv, cfmt, win);
        if (ret < 0)
                return ret;

        priv->win = win;
        priv->cfmt = cfmt;

        return 0;
}

static int ov772x_video_probe(struct ov772x_priv *priv)
{
        struct i2c_client  *client = v4l2_get_subdevdata(&priv->subdev);
        u8                  pid, ver;
        const char         *devname;
        int                 ret;

        ret = ov772x_s_power(&priv->subdev, 1);
        if (ret < 0)
                return ret;

        /* Check and show product ID and manufacturer ID. */
        pid = ov772x_read(client, PID);
        ver = ov772x_read(client, VER);

        switch (VERSION(pid, ver)) {
        case OV7720:
                devname     = "ov7720";
                break;
        case OV7725:
                devname     = "ov7725";
                break;
        default:
                dev_err(&client->dev,
                        "Product ID error %x:%x\n", pid, ver);
                ret = -ENODEV;
                goto done;
        }

        dev_info(&client->dev,
                 "%s Product ID %0x:%0x Manufacturer ID %x:%x\n",
                 devname,
                 pid,
                 ver,
                 ov772x_read(client, MIDH),
                 ov772x_read(client, MIDL));
        ret = v4l2_ctrl_handler_setup(&priv->hdl);

done:
        ov772x_s_power(&priv->subdev, 0);

        return ret;
}

static const struct v4l2_ctrl_ops ov772x_ctrl_ops = {
        .s_ctrl = ov772x_s_ctrl,
};

static const struct v4l2_subdev_core_ops ov772x_subdev_core_ops = {
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register     = ov772x_g_register,
        .s_register     = ov772x_s_register,
#endif
        .s_power        = ov772x_s_power,
};

static int ov772x_enum_frame_interval(struct v4l2_subdev *sd,
                                      struct v4l2_subdev_pad_config *cfg,
                                      struct v4l2_subdev_frame_interval_enum *fie)
{
        if (fie->pad || fie->index >= ARRAY_SIZE(ov772x_frame_intervals))
                return -EINVAL;

        if (fie->width != VGA_WIDTH && fie->width != QVGA_WIDTH)
                return -EINVAL;
        if (fie->height != VGA_HEIGHT && fie->height != QVGA_HEIGHT)
                return -EINVAL;

        fie->interval.numerator = 1;
        fie->interval.denominator = ov772x_frame_intervals[fie->index];

        return 0;
}

static int ov772x_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 >= ARRAY_SIZE(ov772x_cfmts))
                return -EINVAL;

        code->code = ov772x_cfmts[code->index].code;

        return 0;
}

static const struct v4l2_subdev_video_ops ov772x_subdev_video_ops = {
        .s_stream               = ov772x_s_stream,
        .s_frame_interval       = ov772x_s_frame_interval,
        .g_frame_interval       = ov772x_g_frame_interval,
};

static const struct v4l2_subdev_pad_ops ov772x_subdev_pad_ops = {
        .enum_frame_interval    = ov772x_enum_frame_interval,
        .enum_mbus_code         = ov772x_enum_mbus_code,
        .get_selection          = ov772x_get_selection,
        .get_fmt                = ov772x_get_fmt,
        .set_fmt                = ov772x_set_fmt,
};

static const struct v4l2_subdev_ops ov772x_subdev_ops = {
        .core   = &ov772x_subdev_core_ops,
        .video  = &ov772x_subdev_video_ops,
        .pad    = &ov772x_subdev_pad_ops,
};

/*
 * i2c_driver function
 */

static int ov772x_probe(struct i2c_client *client,
                        const struct i2c_device_id *did)
{
        struct ov772x_priv      *priv;
        struct i2c_adapter      *adapter = client->adapter;
        int                     ret;

        if (!client->dev.platform_data) {
                dev_err(&client->dev, "Missing ov772x platform data\n");
                return -EINVAL;
        }

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
                                              I2C_FUNC_PROTOCOL_MANGLING)) {
                dev_err(&adapter->dev,
                        "I2C-Adapter doesn't support SMBUS_BYTE_DATA or PROTOCOL_MANGLING\n");
                return -EIO;
        }
        client->flags |= I2C_CLIENT_SCCB;

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

        priv->info = client->dev.platform_data;

        v4l2_i2c_subdev_init(&priv->subdev, client, &ov772x_subdev_ops);
        v4l2_ctrl_handler_init(&priv->hdl, 3);
        v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,
                          V4L2_CID_VFLIP, 0, 1, 1, 0);
        v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,
                          V4L2_CID_HFLIP, 0, 1, 1, 0);
        v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,
                          V4L2_CID_BAND_STOP_FILTER, 0, 256, 1, 0);
        priv->subdev.ctrl_handler = &priv->hdl;
        if (priv->hdl.error)
                return priv->hdl.error;

        priv->clk = clk_get(&client->dev, "xclk");
        if (IS_ERR(priv->clk)) {
                dev_err(&client->dev, "Unable to get xclk clock\n");
                ret = PTR_ERR(priv->clk);
                goto error_ctrl_free;
        }

        priv->pwdn_gpio = gpiod_get_optional(&client->dev, "pwdn",
                                             GPIOD_OUT_LOW);
        if (IS_ERR(priv->pwdn_gpio)) {
                dev_info(&client->dev, "Unable to get GPIO \"pwdn\"");
                ret = PTR_ERR(priv->pwdn_gpio);
                goto error_clk_put;
        }

        ret = ov772x_video_probe(priv);
        if (ret < 0)
                goto error_gpio_put;

        priv->cfmt = &ov772x_cfmts[0];
        priv->win = &ov772x_win_sizes[0];
        priv->fps = 15;

        ret = v4l2_async_register_subdev(&priv->subdev);
        if (ret)
                goto error_gpio_put;

        return 0;

error_gpio_put:
        if (priv->pwdn_gpio)
                gpiod_put(priv->pwdn_gpio);
error_clk_put:
        clk_put(priv->clk);
error_ctrl_free:
        v4l2_ctrl_handler_free(&priv->hdl);

        return ret;
}

static int ov772x_remove(struct i2c_client *client)
{
        struct ov772x_priv *priv = to_ov772x(i2c_get_clientdata(client));

        clk_put(priv->clk);
        if (priv->pwdn_gpio)
                gpiod_put(priv->pwdn_gpio);
        v4l2_async_unregister_subdev(&priv->subdev);
        v4l2_ctrl_handler_free(&priv->hdl);

        return 0;
}

static const struct i2c_device_id ov772x_id[] = {
        { "ov772x", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, ov772x_id);

static struct i2c_driver ov772x_i2c_driver = {
        .driver = {
                .name = "ov772x",
        },
        .probe    = ov772x_probe,
        .remove   = ov772x_remove,
        .id_table = ov772x_id,
};

module_i2c_driver(ov772x_i2c_driver);

MODULE_DESCRIPTION("V4L2 driver for OV772x image sensor");
MODULE_AUTHOR("Kuninori Morimoto");
MODULE_LICENSE("GPL v2");