/*
 * tw9910 Video Driver
 *
 * Copyright (C) 2008 Renesas Solutions Corp.
 * Kuninori Morimoto <morimoto.kuninori@renesas.com>
 *
 * Based on ov772x driver,
 *
 * Copyright (C) 2008 Kuninori Morimoto <morimoto.kuninori@renesas.com>
 * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
 * Copyright (C) 2008 Magnus Damm
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
 *
 * 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/init.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/videodev2.h>
#include <media/v4l2-chip-ident.h>
#include <media/v4l2-subdev.h>
#include <media/soc_camera.h>
#include <media/tw9910.h>

#define GET_ID(val)  ((val & 0xF8) >> 3)
#define GET_ReV(val) (val & 0x07)

/*
 * register offset
 */
#define ID              0x00 /* Product ID Code Register */
#define STATUS1         0x01 /* Chip Status Register I */
#define INFORM          0x02 /* Input Format */
#define OPFORM          0x03 /* Output Format Control Register */
#define DLYCTR          0x04 /* Hysteresis and HSYNC Delay Control */
#define OUTCTR1         0x05 /* Output Control I */
#define ACNTL1          0x06 /* Analog Control Register 1 */
#define CROP_HI         0x07 /* Cropping Register, High */
#define VDELAY_LO       0x08 /* Vertical Delay Register, Low */
#define VACTIVE_LO      0x09 /* Vertical Active Register, Low */
#define HDELAY_LO       0x0A /* Horizontal Delay Register, Low */
#define HACTIVE_LO      0x0B /* Horizontal Active Register, Low */
#define CNTRL1          0x0C /* Control Register I */
#define VSCALE_LO       0x0D /* Vertical Scaling Register, Low */
#define SCALE_HI        0x0E /* Scaling Register, High */
#define HSCALE_LO       0x0F /* Horizontal Scaling Register, Low */
#define BRIGHT          0x10 /* BRIGHTNESS Control Register */
#define CONTRAST        0x11 /* CONTRAST Control Register */
#define SHARPNESS       0x12 /* SHARPNESS Control Register I */
#define SAT_U           0x13 /* Chroma (U) Gain Register */
#define SAT_V           0x14 /* Chroma (V) Gain Register */
#define HUE             0x15 /* Hue Control Register */
#define CORING1         0x17
#define CORING2         0x18 /* Coring and IF compensation */
#define VBICNTL         0x19 /* VBI Control Register */
#define ACNTL2          0x1A /* Analog Control 2 */
#define OUTCTR2         0x1B /* Output Control 2 */
#define SDT             0x1C /* Standard Selection */
#define SDTR            0x1D /* Standard Recognition */
#define TEST            0x1F /* Test Control Register */
#define CLMPG           0x20 /* Clamping Gain */
#define IAGC            0x21 /* Individual AGC Gain */
#define AGCGAIN         0x22 /* AGC Gain */
#define PEAKWT          0x23 /* White Peak Threshold */
#define CLMPL           0x24 /* Clamp level */
#define SYNCT           0x25 /* Sync Amplitude */
#define MISSCNT         0x26 /* Sync Miss Count Register */
#define PCLAMP          0x27 /* Clamp Position Register */
#define VCNTL1          0x28 /* Vertical Control I */
#define VCNTL2          0x29 /* Vertical Control II */
#define CKILL           0x2A /* Color Killer Level Control */
#define COMB            0x2B /* Comb Filter Control */
#define LDLY            0x2C /* Luma Delay and H Filter Control */
#define MISC1           0x2D /* Miscellaneous Control I */
#define LOOP            0x2E /* LOOP Control Register */
#define MISC2           0x2F /* Miscellaneous Control II */
#define MVSN            0x30 /* Macrovision Detection */
#define STATUS2         0x31 /* Chip STATUS II */
#define HFREF           0x32 /* H monitor */
#define CLMD            0x33 /* CLAMP MODE */
#define IDCNTL          0x34 /* ID Detection Control */
#define CLCNTL1         0x35 /* Clamp Control I */
#define ANAPLLCTL       0x4C
#define VBIMIN          0x4D
#define HSLOWCTL        0x4E
#define WSS3            0x4F
#define FILLDATA        0x50
#define SDID            0x51
#define DID             0x52
#define WSS1            0x53
#define WSS2            0x54
#define VVBI            0x55
#define LCTL6           0x56
#define LCTL7           0x57
#define LCTL8           0x58
#define LCTL9           0x59
#define LCTL10          0x5A
#define LCTL11          0x5B
#define LCTL12          0x5C
#define LCTL13          0x5D
#define LCTL14          0x5E
#define LCTL15          0x5F
#define LCTL16          0x60
#define LCTL17          0x61
#define LCTL18          0x62
#define LCTL19          0x63
#define LCTL20          0x64
#define LCTL21          0x65
#define LCTL22          0x66
#define LCTL23          0x67
#define LCTL24          0x68
#define LCTL25          0x69
#define LCTL26          0x6A
#define HSGEGIN         0x6B
#define HSEND           0x6C
#define OVSDLY          0x6D
#define OVSEND          0x6E
#define VBIDELAY        0x6F

/*
 * register detail
 */

/* INFORM */
#define FC27_ON     0x40 /* 1 : Input crystal clock frequency is 27MHz */
#define FC27_FF     0x00 /* 0 : Square pixel mode. */
                         /*     Must use 24.54MHz for 60Hz field rate */
                         /*     source or 29.5MHz for 50Hz field rate */
#define IFSEL_S     0x10 /* 01 : S-video decoding */
#define IFSEL_C     0x00 /* 00 : Composite video decoding */
                         /* Y input video selection */
#define YSEL_M0     0x00 /*  00 : Mux0 selected */
#define YSEL_M1     0x04 /*  01 : Mux1 selected */
#define YSEL_M2     0x08 /*  10 : Mux2 selected */
#define YSEL_M3     0x10 /*  11 : Mux3 selected */

/* OPFORM */
#define MODE        0x80 /* 0 : CCIR601 compatible YCrCb 4:2:2 format */
                         /* 1 : ITU-R-656 compatible data sequence format */
#define LEN         0x40 /* 0 : 8-bit YCrCb 4:2:2 output format */
                         /* 1 : 16-bit YCrCb 4:2:2 output format.*/
#define LLCMODE     0x20 /* 1 : LLC output mode. */
                         /* 0 : free-run output mode */
#define AINC        0x10 /* Serial interface auto-indexing control */
                         /* 0 : auto-increment */
                         /* 1 : non-auto */
#define VSCTL       0x08 /* 1 : Vertical out ctrl by DVALID */
                         /* 0 : Vertical out ctrl by HACTIVE and DVALID */
#define OEN         0x04 /* Output Enable together with TRI_SEL. */

/* OUTCTR1 */
#define VSP_LO      0x00 /* 0 : VS pin output polarity is active low */
#define VSP_HI      0x80 /* 1 : VS pin output polarity is active high. */
                         /* VS pin output control */
#define VSSL_VSYNC  0x00 /*   0 : VSYNC  */
#define VSSL_VACT   0x10 /*   1 : VACT   */
#define VSSL_FIELD  0x20 /*   2 : FIELD  */
#define VSSL_VVALID 0x30 /*   3 : VVALID */
#define VSSL_ZERO   0x70 /*   7 : 0      */
#define HSP_LOW     0x00 /* 0 : HS pin output polarity is active low */
#define HSP_HI      0x08 /* 1 : HS pin output polarity is active high.*/
                         /* HS pin output control */
#define HSSL_HACT   0x00 /*   0 : HACT   */
#define HSSL_HSYNC  0x01 /*   1 : HSYNC  */
#define HSSL_DVALID 0x02 /*   2 : DVALID */
#define HSSL_HLOCK  0x03 /*   3 : HLOCK  */
#define HSSL_ASYNCW 0x04 /*   4 : ASYNCW */
#define HSSL_ZERO   0x07 /*   7 : 0      */

/* ACNTL1 */
#define SRESET      0x80 /* resets the device to its default state
                          * but all register content remain unchanged.
                          * This bit is self-resetting.
                          */

/* VBICNTL */
/* RTSEL : control the real time signal
*          output from the MPOUT pin
*/
#define RTSEL_MASK  0x07
#define RTSEL_VLOSS 0x00 /* 0000 = Video loss */
#define RTSEL_HLOCK 0x01 /* 0001 = H-lock */
#define RTSEL_SLOCK 0x02 /* 0010 = S-lock */
#define RTSEL_VLOCK 0x03 /* 0011 = V-lock */
#define RTSEL_MONO  0x04 /* 0100 = MONO */
#define RTSEL_DET50 0x05 /* 0101 = DET50 */
#define RTSEL_FIELD 0x06 /* 0110 = FIELD */
#define RTSEL_RTCO  0x07 /* 0111 = RTCO ( Real Time Control ) */

/*
 * structure
 */

struct regval_list {
        unsigned char reg_num;
        unsigned char value;
};

struct tw9910_scale_ctrl {
        char           *name;
        unsigned short  width;
        unsigned short  height;
        u16             hscale;
        u16             vscale;
};

struct tw9910_cropping_ctrl {
        u16 vdelay;
        u16 vactive;
        u16 hdelay;
        u16 hactive;
};

struct tw9910_hsync_ctrl {
        u16 start;
        u16 end;
};

struct tw9910_priv {
        struct v4l2_subdev                subdev;
        struct tw9910_video_info       *info;
        const struct tw9910_scale_ctrl *scale;
};

/*
 * register settings
 */

#define ENDMARKER { 0xff, 0xff }

static const struct regval_list tw9910_default_regs[] =
{
        { OPFORM,  0x00 },
        { OUTCTR1, VSP_LO | VSSL_VVALID | HSP_HI | HSSL_HSYNC },
        ENDMARKER,
};

static const struct soc_camera_data_format tw9910_color_fmt[] = {
        {
                .name       = "VYUY",
                .fourcc     = V4L2_PIX_FMT_VYUY,
                .depth      = 16,
                .colorspace = V4L2_COLORSPACE_SMPTE170M,
        }
};

static const struct tw9910_scale_ctrl tw9910_ntsc_scales[] = {
        {
                .name   = "NTSC SQ",
                .width  = 640,
                .height = 480,
                .hscale = 0x0100,
                .vscale = 0x0100,
        },
        {
                .name   = "NTSC CCIR601",
                .width  = 720,
                .height = 480,
                .hscale = 0x0100,
                .vscale = 0x0100,
        },
        {
                .name   = "NTSC SQ (CIF)",
                .width  = 320,
                .height = 240,
                .hscale = 0x0200,
                .vscale = 0x0200,
        },
        {
                .name   = "NTSC CCIR601 (CIF)",
                .width  = 360,
                .height = 240,
                .hscale = 0x0200,
                .vscale = 0x0200,
        },
        {
                .name   = "NTSC SQ (QCIF)",
                .width  = 160,
                .height = 120,
                .hscale = 0x0400,
                .vscale = 0x0400,
        },
        {
                .name   = "NTSC CCIR601 (QCIF)",
                .width  = 180,
                .height = 120,
                .hscale = 0x0400,
                .vscale = 0x0400,
        },
};

static const struct tw9910_scale_ctrl tw9910_pal_scales[] = {
        {
                .name   = "PAL SQ",
                .width  = 768,
                .height = 576,
                .hscale = 0x0100,
                .vscale = 0x0100,
        },
        {
                .name   = "PAL CCIR601",
                .width  = 720,
                .height = 576,
                .hscale = 0x0100,
                .vscale = 0x0100,
        },
        {
                .name   = "PAL SQ (CIF)",
                .width  = 384,
                .height = 288,
                .hscale = 0x0200,
                .vscale = 0x0200,
        },
        {
                .name   = "PAL CCIR601 (CIF)",
                .width  = 360,
                .height = 288,
                .hscale = 0x0200,
                .vscale = 0x0200,
        },
        {
                .name   = "PAL SQ (QCIF)",
                .width  = 192,
                .height = 144,
                .hscale = 0x0400,
                .vscale = 0x0400,
        },
        {
                .name   = "PAL CCIR601 (QCIF)",
                .width  = 180,
                .height = 144,
                .hscale = 0x0400,
                .vscale = 0x0400,
        },
};

static const struct tw9910_cropping_ctrl tw9910_cropping_ctrl = {
        .vdelay  = 0x0012,
        .vactive = 0x00F0,
        .hdelay  = 0x0010,
        .hactive = 0x02D0,
};

static const struct tw9910_hsync_ctrl tw9910_hsync_ctrl = {
        .start = 0x0260,
        .end   = 0x0300,
};

/*
 * general function
 */
static struct tw9910_priv *to_tw9910(const struct i2c_client *client)
{
        return container_of(i2c_get_clientdata(client), struct tw9910_priv,
                            subdev);
}

static int tw9910_set_scale(struct i2c_client *client,
                            const struct tw9910_scale_ctrl *scale)
{
        int ret;

        ret = i2c_smbus_write_byte_data(client, SCALE_HI,
                                        (scale->vscale & 0x0F00) >> 4 |
                                        (scale->hscale & 0x0F00) >> 8);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(client, HSCALE_LO,
                                        scale->hscale & 0x00FF);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(client, VSCALE_LO,
                                        scale->vscale & 0x00FF);

        return ret;
}

static int tw9910_set_cropping(struct i2c_client *client,
                               const struct tw9910_cropping_ctrl *cropping)
{
        int ret;

        ret = i2c_smbus_write_byte_data(client, CROP_HI,
                                        (cropping->vdelay  & 0x0300) >> 2 |
                                        (cropping->vactive & 0x0300) >> 4 |
                                        (cropping->hdelay  & 0x0300) >> 6 |
                                        (cropping->hactive & 0x0300) >> 8);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(client, VDELAY_LO,
                                        cropping->vdelay & 0x00FF);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(client, VACTIVE_LO,
                                        cropping->vactive & 0x00FF);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(client, HDELAY_LO,
                                        cropping->hdelay & 0x00FF);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(client, HACTIVE_LO,
                                        cropping->hactive & 0x00FF);

        return ret;
}

static int tw9910_set_hsync(struct i2c_client *client,
                            const struct tw9910_hsync_ctrl *hsync)
{
        int ret;

        /* bit 10 - 3 */
        ret = i2c_smbus_write_byte_data(client, HSGEGIN,
                                        (hsync->start & 0x07F8) >> 3);
        if (ret < 0)
                return ret;

        /* bit 10 - 3 */
        ret = i2c_smbus_write_byte_data(client, HSEND,
                                        (hsync->end & 0x07F8) >> 3);
        if (ret < 0)
                return ret;

        /* bit 2 - 0 */
        ret = i2c_smbus_read_byte_data(client, HSLOWCTL);
        if (ret < 0)
                return ret;

        ret = i2c_smbus_write_byte_data(client, HSLOWCTL,
                                        (ret & 0x88)                 |
                                        (hsync->start & 0x0007) << 4 |
                                        (hsync->end   & 0x0007));

        return ret;
}

static int tw9910_write_array(struct i2c_client *client,
                              const struct regval_list *vals)
{
        while (vals->reg_num != 0xff) {
                int ret = i2c_smbus_write_byte_data(client,
                                                    vals->reg_num,
                                                    vals->value);
                if (ret < 0)
                        return ret;
                vals++;
        }
        return 0;
}

static int tw9910_mask_set(struct i2c_client *client, u8 command,
                           u8 mask, u8 set)
{
        s32 val = i2c_smbus_read_byte_data(client, command);
        if (val < 0)
                return val;

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

        return i2c_smbus_write_byte_data(client, command, val);
}

static void tw9910_reset(struct i2c_client *client)
{
        i2c_smbus_write_byte_data(client, ACNTL1, SRESET);
        msleep(1);
}

static const struct tw9910_scale_ctrl*
tw9910_select_norm(struct soc_camera_device *icd, u32 width, u32 height)
{
        const struct tw9910_scale_ctrl *scale;
        const struct tw9910_scale_ctrl *ret = NULL;
        v4l2_std_id norm = icd->vdev->current_norm;
        __u32 diff = 0xffffffff, tmp;
        int size, i;

        if (norm & V4L2_STD_NTSC) {
                scale = tw9910_ntsc_scales;
                size = ARRAY_SIZE(tw9910_ntsc_scales);
        } else if (norm & V4L2_STD_PAL) {
                scale = tw9910_pal_scales;
                size = ARRAY_SIZE(tw9910_pal_scales);
        } else {
                return NULL;
        }

        for (i = 0; i < size; i++) {
                tmp = abs(width - scale[i].width) +
                        abs(height - scale[i].height);
                if (tmp < diff) {
                        diff = tmp;
                        ret = scale + i;
                }
        }

        return ret;
}

/*
 * soc_camera_ops function
 */
static int tw9910_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct i2c_client *client = sd->priv;
        struct tw9910_priv *priv = to_tw9910(client);

        if (!enable)
                return 0;

        if (!priv->scale) {
                dev_err(&client->dev, "norm select error\n");
                return -EPERM;
        }

        dev_dbg(&client->dev, "%s %dx%d\n",
                 priv->scale->name,
                 priv->scale->width,
                 priv->scale->height);

        return 0;
}

static int tw9910_set_bus_param(struct soc_camera_device *icd,
                                unsigned long flags)
{
        return 0;
}

static unsigned long tw9910_query_bus_param(struct soc_camera_device *icd)
{
        struct i2c_client *client = to_i2c_client(to_soc_camera_control(icd));
        struct tw9910_priv *priv = to_tw9910(client);
        struct soc_camera_link *icl = to_soc_camera_link(icd);
        unsigned long flags = SOCAM_PCLK_SAMPLE_RISING | SOCAM_MASTER |
                SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_HSYNC_ACTIVE_HIGH |
                SOCAM_DATA_ACTIVE_HIGH | priv->info->buswidth;

        return soc_camera_apply_sensor_flags(icl, flags);
}

static int tw9910_s_std(struct v4l2_subdev *sd, v4l2_std_id norm)
{
        int ret = -EINVAL;

        if (norm & (V4L2_STD_NTSC | V4L2_STD_PAL))
                ret = 0;

        return ret;
}

static int tw9910_enum_input(struct soc_camera_device *icd,
                             struct v4l2_input *inp)
{
        inp->type = V4L2_INPUT_TYPE_TUNER;
        inp->std  = V4L2_STD_UNKNOWN;
        strcpy(inp->name, "Video");

        return 0;
}

static int tw9910_g_chip_ident(struct v4l2_subdev *sd,
                               struct v4l2_dbg_chip_ident *id)
{
        id->ident = V4L2_IDENT_TW9910;
        id->revision = 0;

        return 0;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int tw9910_g_register(struct v4l2_subdev *sd,
                             struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = sd->priv;
        int ret;

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

        ret = i2c_smbus_read_byte_data(client, reg->reg);
        if (ret < 0)
                return ret;

        /* ret      = int
         * reg->val = __u64
         */
        reg->val = (__u64)ret;

        return 0;
}

static int tw9910_s_register(struct v4l2_subdev *sd,
                             struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = sd->priv;

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

        return i2c_smbus_write_byte_data(client, reg->reg, reg->val);
}
#endif

static int tw9910_s_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
{
        struct v4l2_rect *rect = &a->c;
        struct i2c_client *client = sd->priv;
        struct tw9910_priv *priv = to_tw9910(client);
        struct soc_camera_device *icd = client->dev.platform_data;
        int                 ret  = -EINVAL;
        u8                  val;

        /*
         * select suitable norm
         */
        priv->scale = tw9910_select_norm(icd, rect->width, rect->height);
        if (!priv->scale)
                goto tw9910_set_fmt_error;

        /*
         * reset hardware
         */
        tw9910_reset(client);
        ret = tw9910_write_array(client, tw9910_default_regs);
        if (ret < 0)
                goto tw9910_set_fmt_error;

        /*
         * set bus width
         */
        val = 0x00;
        if (SOCAM_DATAWIDTH_16 == priv->info->buswidth)
                val = LEN;

        ret = tw9910_mask_set(client, OPFORM, LEN, val);
        if (ret < 0)
                goto tw9910_set_fmt_error;

        /*
         * select MPOUT behavior
         */
        switch (priv->info->mpout) {
        case TW9910_MPO_VLOSS:
                val = RTSEL_VLOSS; break;
        case TW9910_MPO_HLOCK:
                val = RTSEL_HLOCK; break;
        case TW9910_MPO_SLOCK:
                val = RTSEL_SLOCK; break;
        case TW9910_MPO_VLOCK:
                val = RTSEL_VLOCK; break;
        case TW9910_MPO_MONO:
                val = RTSEL_MONO;  break;
        case TW9910_MPO_DET50:
                val = RTSEL_DET50; break;
        case TW9910_MPO_FIELD:
                val = RTSEL_FIELD; break;
        case TW9910_MPO_RTCO:
                val = RTSEL_RTCO;  break;
        default:
                val = 0;
        }

        ret = tw9910_mask_set(client, VBICNTL, RTSEL_MASK, val);
        if (ret < 0)
                goto tw9910_set_fmt_error;

        /*
         * set scale
         */
        ret = tw9910_set_scale(client, priv->scale);
        if (ret < 0)
                goto tw9910_set_fmt_error;

        /*
         * set cropping
         */
        ret = tw9910_set_cropping(client, &tw9910_cropping_ctrl);
        if (ret < 0)
                goto tw9910_set_fmt_error;

        /*
         * set hsync
         */
        ret = tw9910_set_hsync(client, &tw9910_hsync_ctrl);
        if (ret < 0)
                goto tw9910_set_fmt_error;

        rect->width = priv->scale->width;
        rect->height = priv->scale->height;
        rect->left = 0;
        rect->top = 0;

        return ret;

tw9910_set_fmt_error:

        tw9910_reset(client);
        priv->scale = NULL;

        return ret;
}

static int tw9910_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
{
        struct i2c_client *client = sd->priv;
        struct tw9910_priv *priv = to_tw9910(client);

        if (!priv->scale) {
                int ret;
                struct v4l2_crop crop = {
                        .c = {
                                .left   = 0,
                                .top    = 0,
                                .width  = 640,
                                .height = 480,
                        },
                };
                ret = tw9910_s_crop(sd, &crop);
                if (ret < 0)
                        return ret;
        }

        a->c.left       = 0;
        a->c.top        = 0;
        a->c.width      = priv->scale->width;
        a->c.height     = priv->scale->height;
        a->type         = V4L2_BUF_TYPE_VIDEO_CAPTURE;

        return 0;
}

static int tw9910_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
{
        a->bounds.left                  = 0;
        a->bounds.top                   = 0;
        a->bounds.width                 = 768;
        a->bounds.height                = 576;
        a->defrect.left                 = 0;
        a->defrect.top                  = 0;
        a->defrect.width                = 640;
        a->defrect.height               = 480;
        a->type                         = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        a->pixelaspect.numerator        = 1;
        a->pixelaspect.denominator      = 1;

        return 0;
}

static int tw9910_g_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
{
        struct i2c_client *client = sd->priv;
        struct tw9910_priv *priv = to_tw9910(client);
        struct v4l2_pix_format *pix = &f->fmt.pix;

        if (!priv->scale) {
                int ret;
                struct v4l2_crop crop = {
                        .c = {
                                .left   = 0,
                                .top    = 0,
                                .width  = 640,
                                .height = 480,
                        },
                };
                ret = tw9910_s_crop(sd, &crop);
                if (ret < 0)
                        return ret;
        }

        f->type                 = V4L2_BUF_TYPE_VIDEO_CAPTURE;

        pix->width              = priv->scale->width;
        pix->height             = priv->scale->height;
        pix->pixelformat        = V4L2_PIX_FMT_VYUY;
        pix->colorspace         = V4L2_COLORSPACE_SMPTE170M;
        pix->field              = V4L2_FIELD_INTERLACED;

        return 0;
}

static int tw9910_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
{
        struct i2c_client *client = sd->priv;
        struct tw9910_priv *priv = to_tw9910(client);
        struct v4l2_pix_format *pix = &f->fmt.pix;
        /* See tw9910_s_crop() - no proper cropping support */
        struct v4l2_crop a = {
                .c = {
                        .left   = 0,
                        .top    = 0,
                        .width  = pix->width,
                        .height = pix->height,
                },
        };
        int i, ret;

        /*
         * check color format
         */
        for (i = 0; i < ARRAY_SIZE(tw9910_color_fmt); i++)
                if (pix->pixelformat == tw9910_color_fmt[i].fourcc)
                        break;

        if (i == ARRAY_SIZE(tw9910_color_fmt))
                return -EINVAL;

        ret = tw9910_s_crop(sd, &a);
        if (!ret) {
                pix->width = priv->scale->width;
                pix->height = priv->scale->height;
        }
        return ret;
}

static int tw9910_try_fmt(struct v4l2_subdev *sd, struct v4l2_format *f)
{
        struct i2c_client *client = sd->priv;
        struct soc_camera_device *icd = client->dev.platform_data;
        struct v4l2_pix_format *pix = &f->fmt.pix;
        const struct tw9910_scale_ctrl *scale;

        if (V4L2_FIELD_ANY == pix->field) {
                pix->field = V4L2_FIELD_INTERLACED;
        } else if (V4L2_FIELD_INTERLACED != pix->field) {
                dev_err(&client->dev, "Field type invalid.\n");
                return -EINVAL;
        }

        /*
         * select suitable norm
         */
        scale = tw9910_select_norm(icd, pix->width, pix->height);
        if (!scale)
                return -EINVAL;

        pix->width  = scale->width;
        pix->height = scale->height;

        return 0;
}

static int tw9910_video_probe(struct soc_camera_device *icd,
                              struct i2c_client *client)
{
        struct tw9910_priv *priv = to_tw9910(client);
        s32 val;

        /*
         * We must have a parent by now. And it cannot be a wrong one.
         * So this entire test is completely redundant.
         */
        if (!icd->dev.parent ||
            to_soc_camera_host(icd->dev.parent)->nr != icd->iface)
                return -ENODEV;

        /*
         * tw9910 only use 8 or 16 bit bus width
         */
        if (SOCAM_DATAWIDTH_16 != priv->info->buswidth &&
            SOCAM_DATAWIDTH_8  != priv->info->buswidth) {
                dev_err(&client->dev, "bus width error\n");
                return -ENODEV;
        }

        icd->formats     = tw9910_color_fmt;
        icd->num_formats = ARRAY_SIZE(tw9910_color_fmt);

        /*
         * check and show Product ID
         */
        val = i2c_smbus_read_byte_data(client, ID);

        if (0x0B != GET_ID(val) ||
            0x00 != GET_ReV(val)) {
                dev_err(&client->dev,
                        "Product ID error %x:%x\n", GET_ID(val), GET_ReV(val));
                return -ENODEV;
        }

        dev_info(&client->dev,
                 "tw9910 Product ID %0x:%0x\n", GET_ID(val), GET_ReV(val));

        icd->vdev->tvnorms      = V4L2_STD_NTSC | V4L2_STD_PAL;
        icd->vdev->current_norm = V4L2_STD_NTSC;

        return 0;
}

static struct soc_camera_ops tw9910_ops = {
        .set_bus_param          = tw9910_set_bus_param,
        .query_bus_param        = tw9910_query_bus_param,
        .enum_input             = tw9910_enum_input,
};

static struct v4l2_subdev_core_ops tw9910_subdev_core_ops = {
        .g_chip_ident   = tw9910_g_chip_ident,
        .s_std          = tw9910_s_std,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register     = tw9910_g_register,
        .s_register     = tw9910_s_register,
#endif
};

static struct v4l2_subdev_video_ops tw9910_subdev_video_ops = {
        .s_stream       = tw9910_s_stream,
        .g_fmt          = tw9910_g_fmt,
        .s_fmt          = tw9910_s_fmt,
        .try_fmt        = tw9910_try_fmt,
        .cropcap        = tw9910_cropcap,
        .g_crop         = tw9910_g_crop,
        .s_crop         = tw9910_s_crop,
};

static struct v4l2_subdev_ops tw9910_subdev_ops = {
        .core   = &tw9910_subdev_core_ops,
        .video  = &tw9910_subdev_video_ops,
};

/*
 * i2c_driver function
 */

static int tw9910_probe(struct i2c_client *client,
                        const struct i2c_device_id *did)

{
        struct tw9910_priv             *priv;
        struct tw9910_video_info       *info;
        struct soc_camera_device       *icd = client->dev.platform_data;
        struct i2c_adapter             *adapter =
                to_i2c_adapter(client->dev.parent);
        struct soc_camera_link         *icl;
        int                             ret;

        if (!icd) {
                dev_err(&client->dev, "TW9910: missing soc-camera data!\n");
                return -EINVAL;
        }

        icl = to_soc_camera_link(icd);
        if (!icl)
                return -EINVAL;

        info = container_of(icl, struct tw9910_video_info, link);

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

        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->info   = info;

        v4l2_i2c_subdev_init(&priv->subdev, client, &tw9910_subdev_ops);

        icd->ops     = &tw9910_ops;
        icd->iface   = info->link.bus_id;

        ret = tw9910_video_probe(icd, client);
        if (ret) {
                icd->ops = NULL;
                i2c_set_clientdata(client, NULL);
                kfree(priv);
        }

        return ret;
}

static int tw9910_remove(struct i2c_client *client)
{
        struct tw9910_priv *priv = to_tw9910(client);
        struct soc_camera_device *icd = client->dev.platform_data;

        icd->ops = NULL;
        i2c_set_clientdata(client, NULL);
        kfree(priv);
        return 0;
}

static const struct i2c_device_id tw9910_id[] = {
        { "tw9910", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, tw9910_id);

static struct i2c_driver tw9910_i2c_driver = {
        .driver = {
                .name = "tw9910",
        },
        .probe    = tw9910_probe,
        .remove   = tw9910_remove,
        .id_table = tw9910_id,
};

/*
 * module function
 */
static int __init tw9910_module_init(void)
{
        return i2c_add_driver(&tw9910_i2c_driver);
}

static void __exit tw9910_module_exit(void)
{
        i2c_del_driver(&tw9910_i2c_driver);
}

module_init(tw9910_module_init);
module_exit(tw9910_module_exit);

MODULE_DESCRIPTION("SoC Camera driver for tw9910");
MODULE_AUTHOR("Kuninori Morimoto");
MODULE_LICENSE("GPL v2");