/*
 * 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 HSBEGIN		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_TRI_SEL_MASK	0x07
#define OEN_TRI_SEL_ALL_ON	0x00 /* Enable output for Rev0/Rev1 */
#define OEN_TRI_SEL_ALL_OFF_r0	0x06 /* All tri-stated for Rev0 */
#define OEN_TRI_SEL_ALL_OFF_r1	0x07 /* All tri-stated for Rev1 */

/* 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.
			  */
#define ACNTL1_PDN_MASK	0x0e
#define CLK_PDN		0x08 /* system clock power down */
#define Y_PDN		0x04 /* Luma ADC power down */
#define C_PDN		0x02 /* Chroma ADC power down */

/* ACNTL2 */
#define ACNTL2_PDN_MASK	0x40
#define PLL_PDN		0x40 /* PLL power down */

/* 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;
	u32				revision;
};

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_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_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 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_hsync(struct i2c_client *client,
			    const struct tw9910_hsync_ctrl *hsync)
{
	struct tw9910_priv *priv = to_tw9910(client);
	int ret;

	/* bit 10 - 3 */
	ret = i2c_smbus_write_byte_data(client, HSBEGIN,
					(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;

	/* So far only revisions 0 and 1 have been seen */
	/* bit 2 - 0 */
	if (1 == priv->revision)
		ret = tw9910_mask_set(client, HSLOWCTL, 0x77,
				      (hsync->start & 0x0007) << 4 |
				      (hsync->end   & 0x0007));

	return ret;
}

static void tw9910_reset(struct i2c_client *client)
{
	tw9910_mask_set(client, ACNTL1, SRESET, SRESET);
	msleep(1);
}

static int tw9910_power(struct i2c_client *client, int enable)
{
	int ret;
	u8 acntl1;
	u8 acntl2;

	if (enable) {
		acntl1 = 0;
		acntl2 = 0;
	} else {
		acntl1 = CLK_PDN | Y_PDN | C_PDN;
		acntl2 = PLL_PDN;
	}

	ret = tw9910_mask_set(client, ACNTL1, ACNTL1_PDN_MASK, acntl1);
	if (ret < 0)
		return ret;

	return tw9910_mask_set(client, ACNTL2, ACNTL2_PDN_MASK, acntl2);
}

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);
	u8 val;
	int ret;

	if (!enable) {
		switch (priv->revision) {
		case 0:
			val = OEN_TRI_SEL_ALL_OFF_r0;
			break;
		case 1:
			val = OEN_TRI_SEL_ALL_OFF_r1;
			break;
		default:
			dev_err(&client->dev, "un-supported revision\n");
			return -EINVAL;
		}
	} else {
		val = OEN_TRI_SEL_ALL_ON;

		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);
	}

	ret = tw9910_mask_set(client, OPFORM, OEN_TRI_SEL_MASK, val);
	if (ret < 0)
		return ret;

	return tw9910_power(client, enable);
}

static int tw9910_set_bus_param(struct soc_camera_device *icd,
				unsigned long flags)
{
	struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
	struct i2c_client *client = sd->priv;
	u8 val = VSSL_VVALID | HSSL_DVALID;

	/*
	 * set OUTCTR1
	 *
	 * We use VVALID and DVALID signals to control VSYNC and HSYNC
	 * outputs, in this mode their polarity is inverted.
	 */
	if (flags & SOCAM_HSYNC_ACTIVE_LOW)
		val |= HSP_HI;

	if (flags & SOCAM_VSYNC_ACTIVE_LOW)
		val |= VSP_HI;

	return i2c_smbus_write_byte_data(client, OUTCTR1, val);
}

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_VSYNC_ACTIVE_LOW  | SOCAM_HSYNC_ACTIVE_LOW  |
		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)
{
	struct i2c_client *client = sd->priv;
	struct tw9910_priv *priv = to_tw9910(client);

	id->ident = V4L2_IDENT_TW9910;
	id->revision = priv->revision;

	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);

	/*
	 * 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 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_mbus_framefmt *mf)
{
	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;
	}

	mf->width	= priv->scale->width;
	mf->height	= priv->scale->height;
	mf->code	= V4L2_MBUS_FMT_YUYV8_2X8_BE;
	mf->colorspace	= V4L2_COLORSPACE_JPEG;
	mf->field	= V4L2_FIELD_INTERLACED_BT;

	return 0;
}

static int tw9910_s_fmt(struct v4l2_subdev *sd,
			struct v4l2_mbus_framefmt *mf)
{
	struct i2c_client *client = sd->priv;
	struct tw9910_priv *priv = to_tw9910(client);
	/* See tw9910_s_crop() - no proper cropping support */
	struct v4l2_crop a = {
		.c = {
			.left	= 0,
			.top	= 0,
			.width	= mf->width,
			.height	= mf->height,
		},
	};
	int ret;

	WARN_ON(mf->field != V4L2_FIELD_ANY &&
		mf->field != V4L2_FIELD_INTERLACED_BT);

	/*
	 * check color format
	 */
	if (mf->code != V4L2_MBUS_FMT_YUYV8_2X8_BE)
		return -EINVAL;

	mf->colorspace = V4L2_COLORSPACE_JPEG;

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

static int tw9910_try_fmt(struct v4l2_subdev *sd,
			  struct v4l2_mbus_framefmt *mf)
{
	struct i2c_client *client = sd->priv;
	struct soc_camera_device *icd = client->dev.platform_data;
	const struct tw9910_scale_ctrl *scale;

	if (V4L2_FIELD_ANY == mf->field) {
		mf->field = V4L2_FIELD_INTERLACED_BT;
	} else if (V4L2_FIELD_INTERLACED_BT != mf->field) {
		dev_err(&client->dev, "Field type %d invalid.\n", mf->field);
		return -EINVAL;
	}

	mf->code = V4L2_MBUS_FMT_YUYV8_2X8_BE;
	mf->colorspace = V4L2_COLORSPACE_JPEG;

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

	mf->width	= scale->width;
	mf->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 id;

	/*
	 * 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;
	}

	/*
	 * check and show Product ID
	 * So far only revisions 0 and 1 have been seen
	 */
	id = i2c_smbus_read_byte_data(client, ID);
	priv->revision = GET_REV(id);
	id = GET_ID(id);

	if (0x0B != id ||
	    0x01 < priv->revision) {
		dev_err(&client->dev,
			"Product ID error %x:%x\n",
			id, priv->revision);
		return -ENODEV;
	}

	dev_info(&client->dev,
		 "tw9910 Product ID %0x:%0x\n", id, priv->revision);

	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 int tw9910_enum_fmt(struct v4l2_subdev *sd, unsigned int index,
			   enum v4l2_mbus_pixelcode *code)
{
	if (index)
		return -EINVAL;

	*code = V4L2_MBUS_FMT_YUYV8_2X8_BE;
	return 0;
}

static struct v4l2_subdev_video_ops tw9910_subdev_video_ops = {
	.s_stream	= tw9910_s_stream,
	.g_mbus_fmt	= tw9910_g_fmt,
	.s_mbus_fmt	= tw9910_s_fmt,
	.try_mbus_fmt	= tw9910_try_fmt,
	.cropcap	= tw9910_cropcap,
	.g_crop		= tw9910_g_crop,
	.s_crop		= tw9910_s_crop,
	.enum_mbus_fmt	= tw9910_enum_fmt,
};

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 || !icl->priv)
		return -EINVAL;

	info = icl->priv;

	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   = icl->bus_id;

	ret = tw9910_video_probe(icd, client);
	if (ret) {
		icd->ops = 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;
	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");