[media] move i2c files into drivers/media/i2c

Move ancillary I2C drivers into drivers/media/i2c, in order to
better organize them.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 1586 insertions, 0 deletions

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
new file mode 100644
index 000000000000..e7c82b297514
--- /dev/null
+++ b/drivers/media/i2c/ov7670.c
@@ -0,0 +1,1586 @@
+/*
+ * A V4L2 driver for OmniVision OV7670 cameras.
+ *
+ * Copyright 2006 One Laptop Per Child Association, Inc.  Written
+ * by Jonathan Corbet with substantial inspiration from Mark
+ * McClelland's ovcamchip code.
+ *
+ * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
+ *
+ * This file may be distributed under the terms of the GNU General
+ * Public License, version 2.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-chip-ident.h>
+#include <media/v4l2-mediabus.h>
+#include <media/ov7670.h>
+
+MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
+MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
+MODULE_LICENSE("GPL");
+
+static bool debug;
+module_param(debug, bool, 0644);
+MODULE_PARM_DESC(debug, "Debug level (0-1)");
+
+/*
+ * Basic window sizes.  These probably belong somewhere more globally
+ * useful.
+ */
+#define VGA_WIDTH	640
+#define VGA_HEIGHT	480
+#define QVGA_WIDTH	320
+#define QVGA_HEIGHT	240
+#define CIF_WIDTH	352
+#define CIF_HEIGHT	288
+#define QCIF_WIDTH	176
+#define	QCIF_HEIGHT	144
+
+/*
+ * The 7670 sits on i2c with ID 0x42
+ */
+#define OV7670_I2C_ADDR 0x42
+
+/* Registers */
+#define REG_GAIN	0x00	/* Gain lower 8 bits (rest in vref) */
+#define REG_BLUE	0x01	/* blue gain */
+#define REG_RED		0x02	/* red gain */
+#define REG_VREF	0x03	/* Pieces of GAIN, VSTART, VSTOP */
+#define REG_COM1	0x04	/* Control 1 */
+#define  COM1_CCIR656	  0x40  /* CCIR656 enable */
+#define REG_BAVE	0x05	/* U/B Average level */
+#define REG_GbAVE	0x06	/* Y/Gb Average level */
+#define REG_AECHH	0x07	/* AEC MS 5 bits */
+#define REG_RAVE	0x08	/* V/R Average level */
+#define REG_COM2	0x09	/* Control 2 */
+#define  COM2_SSLEEP	  0x10	/* Soft sleep mode */
+#define REG_PID		0x0a	/* Product ID MSB */
+#define REG_VER		0x0b	/* Product ID LSB */
+#define REG_COM3	0x0c	/* Control 3 */
+#define  COM3_SWAP	  0x40	  /* Byte swap */
+#define  COM3_SCALEEN	  0x08	  /* Enable scaling */
+#define  COM3_DCWEN	  0x04	  /* Enable downsamp/crop/window */
+#define REG_COM4	0x0d	/* Control 4 */
+#define REG_COM5	0x0e	/* All "reserved" */
+#define REG_COM6	0x0f	/* Control 6 */
+#define REG_AECH	0x10	/* More bits of AEC value */
+#define REG_CLKRC	0x11	/* Clocl control */
+#define   CLK_EXT	  0x40	  /* Use external clock directly */
+#define   CLK_SCALE	  0x3f	  /* Mask for internal clock scale */
+#define REG_COM7	0x12	/* Control 7 */
+#define   COM7_RESET	  0x80	  /* Register reset */
+#define   COM7_FMT_MASK	  0x38
+#define   COM7_FMT_VGA	  0x00
+#define	  COM7_FMT_CIF	  0x20	  /* CIF format */
+#define   COM7_FMT_QVGA	  0x10	  /* QVGA format */
+#define   COM7_FMT_QCIF	  0x08	  /* QCIF format */
+#define	  COM7_RGB	  0x04	  /* bits 0 and 2 - RGB format */
+#define	  COM7_YUV	  0x00	  /* YUV */
+#define	  COM7_BAYER	  0x01	  /* Bayer format */
+#define	  COM7_PBAYER	  0x05	  /* "Processed bayer" */
+#define REG_COM8	0x13	/* Control 8 */
+#define   COM8_FASTAEC	  0x80	  /* Enable fast AGC/AEC */
+#define   COM8_AECSTEP	  0x40	  /* Unlimited AEC step size */
+#define   COM8_BFILT	  0x20	  /* Band filter enable */
+#define   COM8_AGC	  0x04	  /* Auto gain enable */
+#define   COM8_AWB	  0x02	  /* White balance enable */
+#define   COM8_AEC	  0x01	  /* Auto exposure enable */
+#define REG_COM9	0x14	/* Control 9  - gain ceiling */
+#define REG_COM10	0x15	/* Control 10 */
+#define   COM10_HSYNC	  0x40	  /* HSYNC instead of HREF */
+#define   COM10_PCLK_HB	  0x20	  /* Suppress PCLK on horiz blank */
+#define   COM10_HREF_REV  0x08	  /* Reverse HREF */
+#define   COM10_VS_LEAD	  0x04	  /* VSYNC on clock leading edge */
+#define   COM10_VS_NEG	  0x02	  /* VSYNC negative */
+#define   COM10_HS_NEG	  0x01	  /* HSYNC negative */
+#define REG_HSTART	0x17	/* Horiz start high bits */
+#define REG_HSTOP	0x18	/* Horiz stop high bits */
+#define REG_VSTART	0x19	/* Vert start high bits */
+#define REG_VSTOP	0x1a	/* Vert stop high bits */
+#define REG_PSHFT	0x1b	/* Pixel delay after HREF */
+#define REG_MIDH	0x1c	/* Manuf. ID high */
+#define REG_MIDL	0x1d	/* Manuf. ID low */
+#define REG_MVFP	0x1e	/* Mirror / vflip */
+#define   MVFP_MIRROR	  0x20	  /* Mirror image */
+#define   MVFP_FLIP	  0x10	  /* Vertical flip */
+
+#define REG_AEW		0x24	/* AGC upper limit */
+#define REG_AEB		0x25	/* AGC lower limit */
+#define REG_VPT		0x26	/* AGC/AEC fast mode op region */
+#define REG_HSYST	0x30	/* HSYNC rising edge delay */
+#define REG_HSYEN	0x31	/* HSYNC falling edge delay */
+#define REG_HREF	0x32	/* HREF pieces */
+#define REG_TSLB	0x3a	/* lots of stuff */
+#define   TSLB_YLAST	  0x04	  /* UYVY or VYUY - see com13 */
+#define REG_COM11	0x3b	/* Control 11 */
+#define   COM11_NIGHT	  0x80	  /* NIght mode enable */
+#define   COM11_NMFR	  0x60	  /* Two bit NM frame rate */
+#define   COM11_HZAUTO	  0x10	  /* Auto detect 50/60 Hz */
+#define	  COM11_50HZ	  0x08	  /* Manual 50Hz select */
+#define   COM11_EXP	  0x02
+#define REG_COM12	0x3c	/* Control 12 */
+#define   COM12_HREF	  0x80	  /* HREF always */
+#define REG_COM13	0x3d	/* Control 13 */
+#define   COM13_GAMMA	  0x80	  /* Gamma enable */
+#define	  COM13_UVSAT	  0x40	  /* UV saturation auto adjustment */
+#define   COM13_UVSWAP	  0x01	  /* V before U - w/TSLB */
+#define REG_COM14	0x3e	/* Control 14 */
+#define   COM14_DCWEN	  0x10	  /* DCW/PCLK-scale enable */
+#define REG_EDGE	0x3f	/* Edge enhancement factor */
+#define REG_COM15	0x40	/* Control 15 */
+#define   COM15_R10F0	  0x00	  /* Data range 10 to F0 */
+#define	  COM15_R01FE	  0x80	  /*            01 to FE */
+#define   COM15_R00FF	  0xc0	  /*            00 to FF */
+#define   COM15_RGB565	  0x10	  /* RGB565 output */
+#define   COM15_RGB555	  0x30	  /* RGB555 output */
+#define REG_COM16	0x41	/* Control 16 */
+#define   COM16_AWBGAIN   0x08	  /* AWB gain enable */
+#define REG_COM17	0x42	/* Control 17 */
+#define   COM17_AECWIN	  0xc0	  /* AEC window - must match COM4 */
+#define   COM17_CBAR	  0x08	  /* DSP Color bar */
+
+/*
+ * This matrix defines how the colors are generated, must be
+ * tweaked to adjust hue and saturation.
+ *
+ * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
+ *
+ * They are nine-bit signed quantities, with the sign bit
+ * stored in 0x58.  Sign for v-red is bit 0, and up from there.
+ */
+#define	REG_CMATRIX_BASE 0x4f
+#define   CMATRIX_LEN 6
+#define REG_CMATRIX_SIGN 0x58
+
+
+#define REG_BRIGHT	0x55	/* Brightness */
+#define REG_CONTRAS	0x56	/* Contrast control */
+
+#define REG_GFIX	0x69	/* Fix gain control */
+
+#define REG_REG76	0x76	/* OV's name */
+#define   R76_BLKPCOR	  0x80	  /* Black pixel correction enable */
+#define   R76_WHTPCOR	  0x40	  /* White pixel correction enable */
+
+#define REG_RGB444	0x8c	/* RGB 444 control */
+#define   R444_ENABLE	  0x02	  /* Turn on RGB444, overrides 5x5 */
+#define   R444_RGBX	  0x01	  /* Empty nibble at end */
+
+#define REG_HAECC1	0x9f	/* Hist AEC/AGC control 1 */
+#define REG_HAECC2	0xa0	/* Hist AEC/AGC control 2 */
+
+#define REG_BD50MAX	0xa5	/* 50hz banding step limit */
+#define REG_HAECC3	0xa6	/* Hist AEC/AGC control 3 */
+#define REG_HAECC4	0xa7	/* Hist AEC/AGC control 4 */
+#define REG_HAECC5	0xa8	/* Hist AEC/AGC control 5 */
+#define REG_HAECC6	0xa9	/* Hist AEC/AGC control 6 */
+#define REG_HAECC7	0xaa	/* Hist AEC/AGC control 7 */
+#define REG_BD60MAX	0xab	/* 60hz banding step limit */
+
+
+/*
+ * Information we maintain about a known sensor.
+ */
+struct ov7670_format_struct;  /* coming later */
+struct ov7670_info {
+	struct v4l2_subdev sd;
+	struct ov7670_format_struct *fmt;  /* Current format */
+	unsigned char sat;		/* Saturation value */
+	int hue;			/* Hue value */
+	int min_width;			/* Filter out smaller sizes */
+	int min_height;			/* Filter out smaller sizes */
+	int clock_speed;		/* External clock speed (MHz) */
+	u8 clkrc;			/* Clock divider value */
+	bool use_smbus;			/* Use smbus I/O instead of I2C */
+};
+
+static inline struct ov7670_info *to_state(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct ov7670_info, sd);
+}
+
+
+
+/*
+ * The default register settings, as obtained from OmniVision.  There
+ * is really no making sense of most of these - lots of "reserved" values
+ * and such.
+ *
+ * These settings give VGA YUYV.
+ */
+
+struct regval_list {
+	unsigned char reg_num;
+	unsigned char value;
+};
+
+static struct regval_list ov7670_default_regs[] = {
+	{ REG_COM7, COM7_RESET },
+/*
+ * Clock scale: 3 = 15fps
+ *              2 = 20fps
+ *              1 = 30fps
+ */
+	{ REG_CLKRC, 0x1 },	/* OV: clock scale (30 fps) */
+	{ REG_TSLB,  0x04 },	/* OV */
+	{ REG_COM7, 0 },	/* VGA */
+	/*
+	 * Set the hardware window.  These values from OV don't entirely
+	 * make sense - hstop is less than hstart.  But they work...
+	 */
+	{ REG_HSTART, 0x13 },	{ REG_HSTOP, 0x01 },
+	{ REG_HREF, 0xb6 },	{ REG_VSTART, 0x02 },
+	{ REG_VSTOP, 0x7a },	{ REG_VREF, 0x0a },
+
+	{ REG_COM3, 0 },	{ REG_COM14, 0 },
+	/* Mystery scaling numbers */
+	{ 0x70, 0x3a },		{ 0x71, 0x35 },
+	{ 0x72, 0x11 },		{ 0x73, 0xf0 },
+	{ 0xa2, 0x02 },		{ REG_COM10, 0x0 },
+
+	/* Gamma curve values */
+	{ 0x7a, 0x20 },		{ 0x7b, 0x10 },
+	{ 0x7c, 0x1e },		{ 0x7d, 0x35 },
+	{ 0x7e, 0x5a },		{ 0x7f, 0x69 },
+	{ 0x80, 0x76 },		{ 0x81, 0x80 },
+	{ 0x82, 0x88 },		{ 0x83, 0x8f },
+	{ 0x84, 0x96 },		{ 0x85, 0xa3 },
+	{ 0x86, 0xaf },		{ 0x87, 0xc4 },
+	{ 0x88, 0xd7 },		{ 0x89, 0xe8 },
+
+	/* AGC and AEC parameters.  Note we start by disabling those features,
+	   then turn them only after tweaking the values. */
+	{ REG_COM8, COM8_FASTAEC | COM8_AECSTEP | COM8_BFILT },
+	{ REG_GAIN, 0 },	{ REG_AECH, 0 },
+	{ REG_COM4, 0x40 }, /* magic reserved bit */
+	{ REG_COM9, 0x18 }, /* 4x gain + magic rsvd bit */
+	{ REG_BD50MAX, 0x05 },	{ REG_BD60MAX, 0x07 },
+	{ REG_AEW, 0x95 },	{ REG_AEB, 0x33 },
+	{ REG_VPT, 0xe3 },	{ REG_HAECC1, 0x78 },
+	{ REG_HAECC2, 0x68 },	{ 0xa1, 0x03 }, /* magic */
+	{ REG_HAECC3, 0xd8 },	{ REG_HAECC4, 0xd8 },
+	{ REG_HAECC5, 0xf0 },	{ REG_HAECC6, 0x90 },
+	{ REG_HAECC7, 0x94 },
+	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC },
+
+	/* Almost all of these are magic "reserved" values.  */
+	{ REG_COM5, 0x61 },	{ REG_COM6, 0x4b },
+	{ 0x16, 0x02 },		{ REG_MVFP, 0x07 },
+	{ 0x21, 0x02 },		{ 0x22, 0x91 },
+	{ 0x29, 0x07 },		{ 0x33, 0x0b },
+	{ 0x35, 0x0b },		{ 0x37, 0x1d },
+	{ 0x38, 0x71 },		{ 0x39, 0x2a },
+	{ REG_COM12, 0x78 },	{ 0x4d, 0x40 },
+	{ 0x4e, 0x20 },		{ REG_GFIX, 0 },
+	{ 0x6b, 0x4a },		{ 0x74, 0x10 },
+	{ 0x8d, 0x4f },		{ 0x8e, 0 },
+	{ 0x8f, 0 },		{ 0x90, 0 },
+	{ 0x91, 0 },		{ 0x96, 0 },
+	{ 0x9a, 0 },		{ 0xb0, 0x84 },
+	{ 0xb1, 0x0c },		{ 0xb2, 0x0e },
+	{ 0xb3, 0x82 },		{ 0xb8, 0x0a },
+
+	/* More reserved magic, some of which tweaks white balance */
+	{ 0x43, 0x0a },		{ 0x44, 0xf0 },
+	{ 0x45, 0x34 },		{ 0x46, 0x58 },
+	{ 0x47, 0x28 },		{ 0x48, 0x3a },
+	{ 0x59, 0x88 },		{ 0x5a, 0x88 },
+	{ 0x5b, 0x44 },		{ 0x5c, 0x67 },
+	{ 0x5d, 0x49 },		{ 0x5e, 0x0e },
+	{ 0x6c, 0x0a },		{ 0x6d, 0x55 },
+	{ 0x6e, 0x11 },		{ 0x6f, 0x9f }, /* "9e for advance AWB" */
+	{ 0x6a, 0x40 },		{ REG_BLUE, 0x40 },
+	{ REG_RED, 0x60 },
+	{ REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC|COM8_AWB },
+
+	/* Matrix coefficients */
+	{ 0x4f, 0x80 },		{ 0x50, 0x80 },
+	{ 0x51, 0 },		{ 0x52, 0x22 },
+	{ 0x53, 0x5e },		{ 0x54, 0x80 },
+	{ 0x58, 0x9e },
+
+	{ REG_COM16, COM16_AWBGAIN },	{ REG_EDGE, 0 },
+	{ 0x75, 0x05 },		{ 0x76, 0xe1 },
+	{ 0x4c, 0 },		{ 0x77, 0x01 },
+	{ REG_COM13, 0xc3 },	{ 0x4b, 0x09 },
+	{ 0xc9, 0x60 },		{ REG_COM16, 0x38 },
+	{ 0x56, 0x40 },
+
+	{ 0x34, 0x11 },		{ REG_COM11, COM11_EXP|COM11_HZAUTO },
+	{ 0xa4, 0x88 },		{ 0x96, 0 },
+	{ 0x97, 0x30 },		{ 0x98, 0x20 },
+	{ 0x99, 0x30 },		{ 0x9a, 0x84 },
+	{ 0x9b, 0x29 },		{ 0x9c, 0x03 },
+	{ 0x9d, 0x4c },		{ 0x9e, 0x3f },
+	{ 0x78, 0x04 },
+
+	/* Extra-weird stuff.  Some sort of multiplexor register */
+	{ 0x79, 0x01 },		{ 0xc8, 0xf0 },
+	{ 0x79, 0x0f },		{ 0xc8, 0x00 },
+	{ 0x79, 0x10 },		{ 0xc8, 0x7e },
+	{ 0x79, 0x0a },		{ 0xc8, 0x80 },
+	{ 0x79, 0x0b },		{ 0xc8, 0x01 },
+	{ 0x79, 0x0c },		{ 0xc8, 0x0f },
+	{ 0x79, 0x0d },		{ 0xc8, 0x20 },
+	{ 0x79, 0x09 },		{ 0xc8, 0x80 },
+	{ 0x79, 0x02 },		{ 0xc8, 0xc0 },
+	{ 0x79, 0x03 },		{ 0xc8, 0x40 },
+	{ 0x79, 0x05 },		{ 0xc8, 0x30 },
+	{ 0x79, 0x26 },
+
+	{ 0xff, 0xff },	/* END MARKER */
+};
+
+
+/*
+ * Here we'll try to encapsulate the changes for just the output
+ * video format.
+ *
+ * RGB656 and YUV422 come from OV; RGB444 is homebrewed.
+ *
+ * IMPORTANT RULE: the first entry must be for COM7, see ov7670_s_fmt for why.
+ */
+
+
+static struct regval_list ov7670_fmt_yuv422[] = {
+	{ REG_COM7, 0x0 },  /* Selects YUV mode */
+	{ REG_RGB444, 0 },	/* No RGB444 please */
+	{ REG_COM1, 0 },	/* CCIR601 */
+	{ REG_COM15, COM15_R00FF },
+	{ REG_COM9, 0x18 }, /* 4x gain ceiling; 0x8 is reserved bit */
+	{ 0x4f, 0x80 }, 	/* "matrix coefficient 1" */
+	{ 0x50, 0x80 }, 	/* "matrix coefficient 2" */
+	{ 0x51, 0    },		/* vb */
+	{ 0x52, 0x22 }, 	/* "matrix coefficient 4" */
+	{ 0x53, 0x5e }, 	/* "matrix coefficient 5" */
+	{ 0x54, 0x80 }, 	/* "matrix coefficient 6" */
+	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
+	{ 0xff, 0xff },
+};
+
+static struct regval_list ov7670_fmt_rgb565[] = {
+	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
+	{ REG_RGB444, 0 },	/* No RGB444 please */
+	{ REG_COM1, 0x0 },	/* CCIR601 */
+	{ REG_COM15, COM15_RGB565 },
+	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
+	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
+	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
+	{ 0x51, 0    },		/* vb */
+	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
+	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
+	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
+	{ REG_COM13, COM13_GAMMA|COM13_UVSAT },
+	{ 0xff, 0xff },
+};
+
+static struct regval_list ov7670_fmt_rgb444[] = {
+	{ REG_COM7, COM7_RGB },	/* Selects RGB mode */
+	{ REG_RGB444, R444_ENABLE },	/* Enable xxxxrrrr ggggbbbb */
+	{ REG_COM1, 0x0 },	/* CCIR601 */
+	{ REG_COM15, COM15_R01FE|COM15_RGB565 }, /* Data range needed? */
+	{ REG_COM9, 0x38 }, 	/* 16x gain ceiling; 0x8 is reserved bit */
+	{ 0x4f, 0xb3 }, 	/* "matrix coefficient 1" */
+	{ 0x50, 0xb3 }, 	/* "matrix coefficient 2" */
+	{ 0x51, 0    },		/* vb */
+	{ 0x52, 0x3d }, 	/* "matrix coefficient 4" */
+	{ 0x53, 0xa7 }, 	/* "matrix coefficient 5" */
+	{ 0x54, 0xe4 }, 	/* "matrix coefficient 6" */
+	{ REG_COM13, COM13_GAMMA|COM13_UVSAT|0x2 },  /* Magic rsvd bit */
+	{ 0xff, 0xff },
+};
+
+static struct regval_list ov7670_fmt_raw[] = {
+	{ REG_COM7, COM7_BAYER },
+	{ REG_COM13, 0x08 }, /* No gamma, magic rsvd bit */
+	{ REG_COM16, 0x3d }, /* Edge enhancement, denoise */
+	{ REG_REG76, 0xe1 }, /* Pix correction, magic rsvd */
+	{ 0xff, 0xff },
+};
+
+
+
+/*
+ * Low-level register I/O.
+ *
+ * Note that there are two versions of these.  On the XO 1, the
+ * i2c controller only does SMBUS, so that's what we use.  The
+ * ov7670 is not really an SMBUS device, though, so the communication
+ * is not always entirely reliable.
+ */
+static int ov7670_read_smbus(struct v4l2_subdev *sd, unsigned char reg,
+		unsigned char *value)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, reg);
+	if (ret >= 0) {
+		*value = (unsigned char)ret;
+		ret = 0;
+	}
+	return ret;
+}
+
+
+static int ov7670_write_smbus(struct v4l2_subdev *sd, unsigned char reg,
+		unsigned char value)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	int ret = i2c_smbus_write_byte_data(client, reg, value);
+
+	if (reg == REG_COM7 && (value & COM7_RESET))
+		msleep(5);  /* Wait for reset to run */
+	return ret;
+}
+
+/*
+ * On most platforms, we'd rather do straight i2c I/O.
+ */
+static int ov7670_read_i2c(struct v4l2_subdev *sd, unsigned char reg,
+		unsigned char *value)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	u8 data = reg;
+	struct i2c_msg msg;
+	int ret;
+
+	/*
+	 * Send out the register address...
+	 */
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = 1;
+	msg.buf = &data;
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret < 0) {
+		printk(KERN_ERR "Error %d on register write\n", ret);
+		return ret;
+	}
+	/*
+	 * ...then read back the result.
+	 */
+	msg.flags = I2C_M_RD;
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret >= 0) {
+		*value = data;
+		ret = 0;
+	}
+	return ret;
+}
+
+
+static int ov7670_write_i2c(struct v4l2_subdev *sd, unsigned char reg,
+		unsigned char value)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	struct i2c_msg msg;
+	unsigned char data[2] = { reg, value };
+	int ret;
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = 2;
+	msg.buf = data;
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	if (ret > 0)
+		ret = 0;
+	if (reg == REG_COM7 && (value & COM7_RESET))
+		msleep(5);  /* Wait for reset to run */
+	return ret;
+}
+
+static int ov7670_read(struct v4l2_subdev *sd, unsigned char reg,
+		unsigned char *value)
+{
+	struct ov7670_info *info = to_state(sd);
+	if (info->use_smbus)
+		return ov7670_read_smbus(sd, reg, value);
+	else
+		return ov7670_read_i2c(sd, reg, value);
+}
+
+static int ov7670_write(struct v4l2_subdev *sd, unsigned char reg,
+		unsigned char value)
+{
+	struct ov7670_info *info = to_state(sd);
+	if (info->use_smbus)
+		return ov7670_write_smbus(sd, reg, value);
+	else
+		return ov7670_write_i2c(sd, reg, value);
+}
+
+/*
+ * Write a list of register settings; ff/ff stops the process.
+ */
+static int ov7670_write_array(struct v4l2_subdev *sd, struct regval_list *vals)
+{
+	while (vals->reg_num != 0xff || vals->value != 0xff) {
+		int ret = ov7670_write(sd, vals->reg_num, vals->value);
+		if (ret < 0)
+			return ret;
+		vals++;
+	}
+	return 0;
+}
+
+
+/*
+ * Stuff that knows about the sensor.
+ */
+static int ov7670_reset(struct v4l2_subdev *sd, u32 val)
+{
+	ov7670_write(sd, REG_COM7, COM7_RESET);
+	msleep(1);
+	return 0;
+}
+
+
+static int ov7670_init(struct v4l2_subdev *sd, u32 val)
+{
+	return ov7670_write_array(sd, ov7670_default_regs);
+}
+
+
+
+static int ov7670_detect(struct v4l2_subdev *sd)
+{
+	unsigned char v;
+	int ret;
+
+	ret = ov7670_init(sd, 0);
+	if (ret < 0)
+		return ret;
+	ret = ov7670_read(sd, REG_MIDH, &v);
+	if (ret < 0)
+		return ret;
+	if (v != 0x7f) /* OV manuf. id. */
+		return -ENODEV;
+	ret = ov7670_read(sd, REG_MIDL, &v);
+	if (ret < 0)
+		return ret;
+	if (v != 0xa2)
+		return -ENODEV;
+	/*
+	 * OK, we know we have an OmniVision chip...but which one?
+	 */
+	ret = ov7670_read(sd, REG_PID, &v);
+	if (ret < 0)
+		return ret;
+	if (v != 0x76)  /* PID + VER = 0x76 / 0x73 */
+		return -ENODEV;
+	ret = ov7670_read(sd, REG_VER, &v);
+	if (ret < 0)
+		return ret;
+	if (v != 0x73)  /* PID + VER = 0x76 / 0x73 */
+		return -ENODEV;
+	return 0;
+}
+
+
+/*
+ * Store information about the video data format.  The color matrix
+ * is deeply tied into the format, so keep the relevant values here.
+ * The magic matrix numbers come from OmniVision.
+ */
+static struct ov7670_format_struct {
+	enum v4l2_mbus_pixelcode mbus_code;
+	enum v4l2_colorspace colorspace;
+	struct regval_list *regs;
+	int cmatrix[CMATRIX_LEN];
+} ov7670_formats[] = {
+	{
+		.mbus_code	= V4L2_MBUS_FMT_YUYV8_2X8,
+		.colorspace	= V4L2_COLORSPACE_JPEG,
+		.regs 		= ov7670_fmt_yuv422,
+		.cmatrix	= { 128, -128, 0, -34, -94, 128 },
+	},
+	{
+		.mbus_code	= V4L2_MBUS_FMT_RGB444_2X8_PADHI_LE,
+		.colorspace	= V4L2_COLORSPACE_SRGB,
+		.regs		= ov7670_fmt_rgb444,
+		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
+	},
+	{
+		.mbus_code	= V4L2_MBUS_FMT_RGB565_2X8_LE,
+		.colorspace	= V4L2_COLORSPACE_SRGB,
+		.regs		= ov7670_fmt_rgb565,
+		.cmatrix	= { 179, -179, 0, -61, -176, 228 },
+	},
+	{
+		.mbus_code	= V4L2_MBUS_FMT_SBGGR8_1X8,
+		.colorspace	= V4L2_COLORSPACE_SRGB,
+		.regs 		= ov7670_fmt_raw,
+		.cmatrix	= { 0, 0, 0, 0, 0, 0 },
+	},
+};
+#define N_OV7670_FMTS ARRAY_SIZE(ov7670_formats)
+
+
+/*
+ * Then there is the issue of window sizes.  Try to capture the info here.
+ */
+
+/*
+ * QCIF mode is done (by OV) in a very strange way - it actually looks like
+ * VGA with weird scaling options - they do *not* use the canned QCIF mode
+ * which is allegedly provided by the sensor.  So here's the weird register
+ * settings.
+ */
+static struct regval_list ov7670_qcif_regs[] = {
+	{ REG_COM3, COM3_SCALEEN|COM3_DCWEN },
+	{ REG_COM3, COM3_DCWEN },
+	{ REG_COM14, COM14_DCWEN | 0x01},
+	{ 0x73, 0xf1 },
+	{ 0xa2, 0x52 },
+	{ 0x7b, 0x1c },
+	{ 0x7c, 0x28 },
+	{ 0x7d, 0x3c },
+	{ 0x7f, 0x69 },
+	{ REG_COM9, 0x38 },
+	{ 0xa1, 0x0b },
+	{ 0x74, 0x19 },
+	{ 0x9a, 0x80 },
+	{ 0x43, 0x14 },
+	{ REG_COM13, 0xc0 },
+	{ 0xff, 0xff },
+};
+
+static struct ov7670_win_size {
+	int	width;
+	int	height;
+	unsigned char com7_bit;
+	int	hstart;		/* Start/stop values for the camera.  Note */
+	int	hstop;		/* that they do not always make complete */
+	int	vstart;		/* sense to humans, but evidently the sensor */
+	int	vstop;		/* will do the right thing... */
+	struct regval_list *regs; /* Regs to tweak */
+/* h/vref stuff */
+} ov7670_win_sizes[] = {
+	/* VGA */
+	{
+		.width		= VGA_WIDTH,
+		.height		= VGA_HEIGHT,
+		.com7_bit	= COM7_FMT_VGA,
+		.hstart		= 158,		/* These values from */
+		.hstop		=  14,		/* Omnivision */
+		.vstart		=  10,
+		.vstop		= 490,
+		.regs 		= NULL,
+	},
+	/* CIF */
+	{
+		.width		= CIF_WIDTH,
+		.height		= CIF_HEIGHT,
+		.com7_bit	= COM7_FMT_CIF,
+		.hstart		= 170,		/* Empirically determined */
+		.hstop		=  90,
+		.vstart		=  14,
+		.vstop		= 494,
+		.regs 		= NULL,
+	},
+	/* QVGA */
+	{
+		.width		= QVGA_WIDTH,
+		.height		= QVGA_HEIGHT,
+		.com7_bit	= COM7_FMT_QVGA,
+		.hstart		= 168,		/* Empirically determined */
+		.hstop		=  24,
+		.vstart		=  12,
+		.vstop		= 492,
+		.regs 		= NULL,
+	},
+	/* QCIF */
+	{
+		.width		= QCIF_WIDTH,
+		.height		= QCIF_HEIGHT,
+		.com7_bit	= COM7_FMT_VGA, /* see comment above */
+		.hstart		= 456,		/* Empirically determined */
+		.hstop		=  24,
+		.vstart		=  14,
+		.vstop		= 494,
+		.regs 		= ov7670_qcif_regs,
+	},
+};
+
+#define N_WIN_SIZES (ARRAY_SIZE(ov7670_win_sizes))
+
+
+/*
+ * Store a set of start/stop values into the camera.
+ */
+static int ov7670_set_hw(struct v4l2_subdev *sd, int hstart, int hstop,
+		int vstart, int vstop)
+{
+	int ret;
+	unsigned char v;
+/*
+ * Horizontal: 11 bits, top 8 live in hstart and hstop.  Bottom 3 of
+ * hstart are in href[2:0], bottom 3 of hstop in href[5:3].  There is
+ * a mystery "edge offset" value in the top two bits of href.
+ */
+	ret =  ov7670_write(sd, REG_HSTART, (hstart >> 3) & 0xff);
+	ret += ov7670_write(sd, REG_HSTOP, (hstop >> 3) & 0xff);
+	ret += ov7670_read(sd, REG_HREF, &v);
+	v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
+	msleep(10);
+	ret += ov7670_write(sd, REG_HREF, v);
+/*
+ * Vertical: similar arrangement, but only 10 bits.
+ */
+	ret += ov7670_write(sd, REG_VSTART, (vstart >> 2) & 0xff);
+	ret += ov7670_write(sd, REG_VSTOP, (vstop >> 2) & 0xff);
+	ret += ov7670_read(sd, REG_VREF, &v);
+	v = (v & 0xf0) | ((vstop & 0x3) << 2) | (vstart & 0x3);
+	msleep(10);
+	ret += ov7670_write(sd, REG_VREF, v);
+	return ret;
+}
+
+
+static int ov7670_enum_mbus_fmt(struct v4l2_subdev *sd, unsigned index,
+					enum v4l2_mbus_pixelcode *code)
+{
+	if (index >= N_OV7670_FMTS)
+		return -EINVAL;
+
+	*code = ov7670_formats[index].mbus_code;
+	return 0;
+}
+
+static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
+		struct v4l2_mbus_framefmt *fmt,
+		struct ov7670_format_struct **ret_fmt,
+		struct ov7670_win_size **ret_wsize)
+{
+	int index;
+	struct ov7670_win_size *wsize;
+
+	for (index = 0; index < N_OV7670_FMTS; index++)
+		if (ov7670_formats[index].mbus_code == fmt->code)
+			break;
+	if (index >= N_OV7670_FMTS) {
+		/* default to first format */
+		index = 0;
+		fmt->code = ov7670_formats[0].mbus_code;
+	}
+	if (ret_fmt != NULL)
+		*ret_fmt = ov7670_formats + index;
+	/*
+	 * Fields: the OV devices claim to be progressive.
+	 */
+	fmt->field = V4L2_FIELD_NONE;
+	/*
+	 * Round requested image size down to the nearest
+	 * we support, but not below the smallest.
+	 */
+	for (wsize = ov7670_win_sizes; wsize < ov7670_win_sizes + N_WIN_SIZES;
+	     wsize++)
+		if (fmt->width >= wsize->width && fmt->height >= wsize->height)
+			break;
+	if (wsize >= ov7670_win_sizes + N_WIN_SIZES)
+		wsize--;   /* Take the smallest one */
+	if (ret_wsize != NULL)
+		*ret_wsize = wsize;
+	/*
+	 * Note the size we'll actually handle.
+	 */
+	fmt->width = wsize->width;
+	fmt->height = wsize->height;
+	fmt->colorspace = ov7670_formats[index].colorspace;
+	return 0;
+}
+
+static int ov7670_try_mbus_fmt(struct v4l2_subdev *sd,
+			    struct v4l2_mbus_framefmt *fmt)
+{
+	return ov7670_try_fmt_internal(sd, fmt, NULL, NULL);
+}
+
+/*
+ * Set a format.
+ */
+static int ov7670_s_mbus_fmt(struct v4l2_subdev *sd,
+			  struct v4l2_mbus_framefmt *fmt)
+{
+	struct ov7670_format_struct *ovfmt;
+	struct ov7670_win_size *wsize;
+	struct ov7670_info *info = to_state(sd);
+	unsigned char com7;
+	int ret;
+
+	ret = ov7670_try_fmt_internal(sd, fmt, &ovfmt, &wsize);
+
+	if (ret)
+		return ret;
+	/*
+	 * COM7 is a pain in the ass, it doesn't like to be read then
+	 * quickly written afterward.  But we have everything we need
+	 * to set it absolutely here, as long as the format-specific
+	 * register sets list it first.
+	 */
+	com7 = ovfmt->regs[0].value;
+	com7 |= wsize->com7_bit;
+	ov7670_write(sd, REG_COM7, com7);
+	/*
+	 * Now write the rest of the array.  Also store start/stops
+	 */
+	ov7670_write_array(sd, ovfmt->regs + 1);
+	ov7670_set_hw(sd, wsize->hstart, wsize->hstop, wsize->vstart,
+			wsize->vstop);
+	ret = 0;
+	if (wsize->regs)
+		ret = ov7670_write_array(sd, wsize->regs);
+	info->fmt = ovfmt;
+
+	/*
+	 * If we're running RGB565, we must rewrite clkrc after setting
+	 * the other parameters or the image looks poor.  If we're *not*
+	 * doing RGB565, we must not rewrite clkrc or the image looks
+	 * *really* poor.
+	 *
+	 * (Update) Now that we retain clkrc state, we should be able
+	 * to write it unconditionally, and that will make the frame
+	 * rate persistent too.
+	 */
+	if (ret == 0)
+		ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
+	return 0;
+}
+
+/*
+ * Implement G/S_PARM.  There is a "high quality" mode we could try
+ * to do someday; for now, we just do the frame rate tweak.
+ */
+static int ov7670_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
+{
+	struct v4l2_captureparm *cp = &parms->parm.capture;
+	struct ov7670_info *info = to_state(sd);
+
+	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	memset(cp, 0, sizeof(struct v4l2_captureparm));
+	cp->capability = V4L2_CAP_TIMEPERFRAME;
+	cp->timeperframe.numerator = 1;
+	cp->timeperframe.denominator = info->clock_speed;
+	if ((info->clkrc & CLK_EXT) == 0 && (info->clkrc & CLK_SCALE) > 1)
+		cp->timeperframe.denominator /= (info->clkrc & CLK_SCALE);
+	return 0;
+}
+
+static int ov7670_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
+{
+	struct v4l2_captureparm *cp = &parms->parm.capture;
+	struct v4l2_fract *tpf = &cp->timeperframe;
+	struct ov7670_info *info = to_state(sd);
+	int div;
+
+	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+	if (cp->extendedmode != 0)
+		return -EINVAL;
+
+	if (tpf->numerator == 0 || tpf->denominator == 0)
+		div = 1;  /* Reset to full rate */
+	else
+		div = (tpf->numerator * info->clock_speed) / tpf->denominator;
+	if (div == 0)
+		div = 1;
+	else if (div > CLK_SCALE)
+		div = CLK_SCALE;
+	info->clkrc = (info->clkrc & 0x80) | div;
+	tpf->numerator = 1;
+	tpf->denominator = info->clock_speed / div;
+	return ov7670_write(sd, REG_CLKRC, info->clkrc);
+}
+
+
+/*
+ * Frame intervals.  Since frame rates are controlled with the clock
+ * divider, we can only do 30/n for integer n values.  So no continuous
+ * or stepwise options.  Here we just pick a handful of logical values.
+ */
+
+static int ov7670_frame_rates[] = { 30, 15, 10, 5, 1 };
+
+static int ov7670_enum_frameintervals(struct v4l2_subdev *sd,
+		struct v4l2_frmivalenum *interval)
+{
+	if (interval->index >= ARRAY_SIZE(ov7670_frame_rates))
+		return -EINVAL;
+	interval->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+	interval->discrete.numerator = 1;
+	interval->discrete.denominator = ov7670_frame_rates[interval->index];
+	return 0;
+}
+
+/*
+ * Frame size enumeration
+ */
+static int ov7670_enum_framesizes(struct v4l2_subdev *sd,
+		struct v4l2_frmsizeenum *fsize)
+{
+	struct ov7670_info *info = to_state(sd);
+	int i;
+	int num_valid = -1;
+	__u32 index = fsize->index;
+
+	/*
+	 * If a minimum width/height was requested, filter out the capture
+	 * windows that fall outside that.
+	 */
+	for (i = 0; i < N_WIN_SIZES; i++) {
+		struct ov7670_win_size *win = &ov7670_win_sizes[index];
+		if (info->min_width && win->width < info->min_width)
+			continue;
+		if (info->min_height && win->height < info->min_height)
+			continue;
+		if (index == ++num_valid) {
+			fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+			fsize->discrete.width = win->width;
+			fsize->discrete.height = win->height;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * Code for dealing with controls.
+ */
+
+static int ov7670_store_cmatrix(struct v4l2_subdev *sd,
+		int matrix[CMATRIX_LEN])
+{
+	int i, ret;
+	unsigned char signbits = 0;
+
+	/*
+	 * Weird crap seems to exist in the upper part of
+	 * the sign bits register, so let's preserve it.
+	 */
+	ret = ov7670_read(sd, REG_CMATRIX_SIGN, &signbits);
+	signbits &= 0xc0;
+
+	for (i = 0; i < CMATRIX_LEN; i++) {
+		unsigned char raw;
+
+		if (matrix[i] < 0) {
+			signbits |= (1 << i);
+			if (matrix[i] < -255)
+				raw = 0xff;
+			else
+				raw = (-1 * matrix[i]) & 0xff;
+		}
+		else {
+			if (matrix[i] > 255)
+				raw = 0xff;
+			else
+				raw = matrix[i] & 0xff;
+		}
+		ret += ov7670_write(sd, REG_CMATRIX_BASE + i, raw);
+	}
+	ret += ov7670_write(sd, REG_CMATRIX_SIGN, signbits);
+	return ret;
+}
+
+
+/*
+ * Hue also requires messing with the color matrix.  It also requires
+ * trig functions, which tend not to be well supported in the kernel.
+ * So here is a simple table of sine values, 0-90 degrees, in steps
+ * of five degrees.  Values are multiplied by 1000.
+ *
+ * The following naive approximate trig functions require an argument
+ * carefully limited to -180 <= theta <= 180.
+ */
+#define SIN_STEP 5
+static const int ov7670_sin_table[] = {
+	   0,	 87,   173,   258,   342,   422,
+	 499,	573,   642,   707,   766,   819,
+	 866,	906,   939,   965,   984,   996,
+	1000
+};
+
+static int ov7670_sine(int theta)
+{
+	int chs = 1;
+	int sine;
+
+	if (theta < 0) {
+		theta = -theta;
+		chs = -1;
+	}
+	if (theta <= 90)
+		sine = ov7670_sin_table[theta/SIN_STEP];
+	else {
+		theta -= 90;
+		sine = 1000 - ov7670_sin_table[theta/SIN_STEP];
+	}
+	return sine*chs;
+}
+
+static int ov7670_cosine(int theta)
+{
+	theta = 90 - theta;
+	if (theta > 180)
+		theta -= 360;
+	else if (theta < -180)
+		theta += 360;
+	return ov7670_sine(theta);
+}
+
+
+
+
+static void ov7670_calc_cmatrix(struct ov7670_info *info,
+		int matrix[CMATRIX_LEN])
+{
+	int i;
+	/*
+	 * Apply the current saturation setting first.
+	 */
+	for (i = 0; i < CMATRIX_LEN; i++)
+		matrix[i] = (info->fmt->cmatrix[i]*info->sat) >> 7;
+	/*
+	 * Then, if need be, rotate the hue value.
+	 */
+	if (info->hue != 0) {
+		int sinth, costh, tmpmatrix[CMATRIX_LEN];
+
+		memcpy(tmpmatrix, matrix, CMATRIX_LEN*sizeof(int));
+		sinth = ov7670_sine(info->hue);
+		costh = ov7670_cosine(info->hue);
+
+		matrix[0] = (matrix[3]*sinth + matrix[0]*costh)/1000;
+		matrix[1] = (matrix[4]*sinth + matrix[1]*costh)/1000;
+		matrix[2] = (matrix[5]*sinth + matrix[2]*costh)/1000;
+		matrix[3] = (matrix[3]*costh - matrix[0]*sinth)/1000;
+		matrix[4] = (matrix[4]*costh - matrix[1]*sinth)/1000;
+		matrix[5] = (matrix[5]*costh - matrix[2]*sinth)/1000;
+	}
+}
+
+
+
+static int ov7670_s_sat(struct v4l2_subdev *sd, int value)
+{
+	struct ov7670_info *info = to_state(sd);
+	int matrix[CMATRIX_LEN];
+	int ret;
+
+	info->sat = value;
+	ov7670_calc_cmatrix(info, matrix);
+	ret = ov7670_store_cmatrix(sd, matrix);
+	return ret;
+}
+
+static int ov7670_g_sat(struct v4l2_subdev *sd, __s32 *value)
+{
+	struct ov7670_info *info = to_state(sd);
+
+	*value = info->sat;
+	return 0;
+}
+
+static int ov7670_s_hue(struct v4l2_subdev *sd, int value)
+{
+	struct ov7670_info *info = to_state(sd);
+	int matrix[CMATRIX_LEN];
+	int ret;
+
+	if (value < -180 || value > 180)
+		return -EINVAL;
+	info->hue = value;
+	ov7670_calc_cmatrix(info, matrix);
+	ret = ov7670_store_cmatrix(sd, matrix);
+	return ret;
+}
+
+
+static int ov7670_g_hue(struct v4l2_subdev *sd, __s32 *value)
+{
+	struct ov7670_info *info = to_state(sd);
+
+	*value = info->hue;
+	return 0;
+}
+
+
+/*
+ * Some weird registers seem to store values in a sign/magnitude format!
+ */
+static unsigned char ov7670_sm_to_abs(unsigned char v)
+{
+	if ((v & 0x80) == 0)
+		return v + 128;
+	return 128 - (v & 0x7f);
+}
+
+
+static unsigned char ov7670_abs_to_sm(unsigned char v)
+{
+	if (v > 127)
+		return v & 0x7f;
+	return (128 - v) | 0x80;
+}
+
+static int ov7670_s_brightness(struct v4l2_subdev *sd, int value)
+{
+	unsigned char com8 = 0, v;
+	int ret;
+
+	ov7670_read(sd, REG_COM8, &com8);
+	com8 &= ~COM8_AEC;
+	ov7670_write(sd, REG_COM8, com8);
+	v = ov7670_abs_to_sm(value);
+	ret = ov7670_write(sd, REG_BRIGHT, v);
+	return ret;
+}
+
+static int ov7670_g_brightness(struct v4l2_subdev *sd, __s32 *value)
+{
+	unsigned char v = 0;
+	int ret = ov7670_read(sd, REG_BRIGHT, &v);
+
+	*value = ov7670_sm_to_abs(v);
+	return ret;
+}
+
+static int ov7670_s_contrast(struct v4l2_subdev *sd, int value)
+{
+	return ov7670_write(sd, REG_CONTRAS, (unsigned char) value);
+}
+
+static int ov7670_g_contrast(struct v4l2_subdev *sd, __s32 *value)
+{
+	unsigned char v = 0;
+	int ret = ov7670_read(sd, REG_CONTRAS, &v);
+
+	*value = v;
+	return ret;
+}
+
+static int ov7670_g_hflip(struct v4l2_subdev *sd, __s32 *value)
+{
+	int ret;
+	unsigned char v = 0;
+
+	ret = ov7670_read(sd, REG_MVFP, &v);
+	*value = (v & MVFP_MIRROR) == MVFP_MIRROR;
+	return ret;
+}
+
+
+static int ov7670_s_hflip(struct v4l2_subdev *sd, int value)
+{
+	unsigned char v = 0;
+	int ret;
+
+	ret = ov7670_read(sd, REG_MVFP, &v);
+	if (value)
+		v |= MVFP_MIRROR;
+	else
+		v &= ~MVFP_MIRROR;
+	msleep(10);  /* FIXME */
+	ret += ov7670_write(sd, REG_MVFP, v);
+	return ret;
+}
+
+
+
+static int ov7670_g_vflip(struct v4l2_subdev *sd, __s32 *value)
+{
+	int ret;
+	unsigned char v = 0;
+
+	ret = ov7670_read(sd, REG_MVFP, &v);
+	*value = (v & MVFP_FLIP) == MVFP_FLIP;
+	return ret;
+}
+
+
+static int ov7670_s_vflip(struct v4l2_subdev *sd, int value)
+{
+	unsigned char v = 0;
+	int ret;
+
+	ret = ov7670_read(sd, REG_MVFP, &v);
+	if (value)
+		v |= MVFP_FLIP;
+	else
+		v &= ~MVFP_FLIP;
+	msleep(10);  /* FIXME */
+	ret += ov7670_write(sd, REG_MVFP, v);
+	return ret;
+}
+
+/*
+ * GAIN is split between REG_GAIN and REG_VREF[7:6].  If one believes
+ * the data sheet, the VREF parts should be the most significant, but
+ * experience shows otherwise.  There seems to be little value in
+ * messing with the VREF bits, so we leave them alone.
+ */
+static int ov7670_g_gain(struct v4l2_subdev *sd, __s32 *value)
+{
+	int ret;
+	unsigned char gain;
+
+	ret = ov7670_read(sd, REG_GAIN, &gain);
+	*value = gain;
+	return ret;
+}
+
+static int ov7670_s_gain(struct v4l2_subdev *sd, int value)
+{
+	int ret;
+	unsigned char com8;
+
+	ret = ov7670_write(sd, REG_GAIN, value & 0xff);
+	/* Have to turn off AGC as well */
+	if (ret == 0) {
+		ret = ov7670_read(sd, REG_COM8, &com8);
+		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AGC);
+	}
+	return ret;
+}
+
+/*
+ * Tweak autogain.
+ */
+static int ov7670_g_autogain(struct v4l2_subdev *sd, __s32 *value)
+{
+	int ret;
+	unsigned char com8;
+
+	ret = ov7670_read(sd, REG_COM8, &com8);
+	*value = (com8 & COM8_AGC) != 0;
+	return ret;
+}
+
+static int ov7670_s_autogain(struct v4l2_subdev *sd, int value)
+{
+	int ret;
+	unsigned char com8;
+
+	ret = ov7670_read(sd, REG_COM8, &com8);
+	if (ret == 0) {
+		if (value)
+			com8 |= COM8_AGC;
+		else
+			com8 &= ~COM8_AGC;
+		ret = ov7670_write(sd, REG_COM8, com8);
+	}
+	return ret;
+}
+
+/*
+ * Exposure is spread all over the place: top 6 bits in AECHH, middle
+ * 8 in AECH, and two stashed in COM1 just for the hell of it.
+ */
+static int ov7670_g_exp(struct v4l2_subdev *sd, __s32 *value)
+{
+	int ret;
+	unsigned char com1, aech, aechh;
+
+	ret = ov7670_read(sd, REG_COM1, &com1) +
+		ov7670_read(sd, REG_AECH, &aech) +
+		ov7670_read(sd, REG_AECHH, &aechh);
+	*value = ((aechh & 0x3f) << 10) | (aech << 2) | (com1 & 0x03);
+	return ret;
+}
+
+static int ov7670_s_exp(struct v4l2_subdev *sd, int value)
+{
+	int ret;
+	unsigned char com1, com8, aech, aechh;
+
+	ret = ov7670_read(sd, REG_COM1, &com1) +
+		ov7670_read(sd, REG_COM8, &com8);
+		ov7670_read(sd, REG_AECHH, &aechh);
+	if (ret)
+		return ret;
+
+	com1 = (com1 & 0xfc) | (value & 0x03);
+	aech = (value >> 2) & 0xff;
+	aechh = (aechh & 0xc0) | ((value >> 10) & 0x3f);
+	ret = ov7670_write(sd, REG_COM1, com1) +
+		ov7670_write(sd, REG_AECH, aech) +
+		ov7670_write(sd, REG_AECHH, aechh);
+	/* Have to turn off AEC as well */
+	if (ret == 0)
+		ret = ov7670_write(sd, REG_COM8, com8 & ~COM8_AEC);
+	return ret;
+}
+
+/*
+ * Tweak autoexposure.
+ */
+static int ov7670_g_autoexp(struct v4l2_subdev *sd, __s32 *value)
+{
+	int ret;
+	unsigned char com8;
+	enum v4l2_exposure_auto_type *atype = (enum v4l2_exposure_auto_type *) value;
+
+	ret = ov7670_read(sd, REG_COM8, &com8);
+	if (com8 & COM8_AEC)
+		*atype = V4L2_EXPOSURE_AUTO;
+	else
+		*atype = V4L2_EXPOSURE_MANUAL;
+	return ret;
+}
+
+static int ov7670_s_autoexp(struct v4l2_subdev *sd,
+		enum v4l2_exposure_auto_type value)
+{
+	int ret;
+	unsigned char com8;
+
+	ret = ov7670_read(sd, REG_COM8, &com8);
+	if (ret == 0) {
+		if (value == V4L2_EXPOSURE_AUTO)
+			com8 |= COM8_AEC;
+		else
+			com8 &= ~COM8_AEC;
+		ret = ov7670_write(sd, REG_COM8, com8);
+	}
+	return ret;
+}
+
+
+
+static int ov7670_queryctrl(struct v4l2_subdev *sd,
+		struct v4l2_queryctrl *qc)
+{
+	/* Fill in min, max, step and default value for these controls. */
+	switch (qc->id) {
+	case V4L2_CID_BRIGHTNESS:
+		return v4l2_ctrl_query_fill(qc, 0, 255, 1, 128);
+	case V4L2_CID_CONTRAST:
+		return v4l2_ctrl_query_fill(qc, 0, 127, 1, 64);
+	case V4L2_CID_VFLIP:
+	case V4L2_CID_HFLIP:
+		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 0);
+	case V4L2_CID_SATURATION:
+		return v4l2_ctrl_query_fill(qc, 0, 256, 1, 128);
+	case V4L2_CID_HUE:
+		return v4l2_ctrl_query_fill(qc, -180, 180, 5, 0);
+	case V4L2_CID_GAIN:
+		return v4l2_ctrl_query_fill(qc, 0, 255, 1, 128);
+	case V4L2_CID_AUTOGAIN:
+		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
+	case V4L2_CID_EXPOSURE:
+		return v4l2_ctrl_query_fill(qc, 0, 65535, 1, 500);
+	case V4L2_CID_EXPOSURE_AUTO:
+		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 0);
+	}
+	return -EINVAL;
+}
+
+static int ov7670_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
+{
+	switch (ctrl->id) {
+	case V4L2_CID_BRIGHTNESS:
+		return ov7670_g_brightness(sd, &ctrl->value);
+	case V4L2_CID_CONTRAST:
+		return ov7670_g_contrast(sd, &ctrl->value);
+	case V4L2_CID_SATURATION:
+		return ov7670_g_sat(sd, &ctrl->value);
+	case V4L2_CID_HUE:
+		return ov7670_g_hue(sd, &ctrl->value);
+	case V4L2_CID_VFLIP:
+		return ov7670_g_vflip(sd, &ctrl->value);
+	case V4L2_CID_HFLIP:
+		return ov7670_g_hflip(sd, &ctrl->value);
+	case V4L2_CID_GAIN:
+		return ov7670_g_gain(sd, &ctrl->value);
+	case V4L2_CID_AUTOGAIN:
+		return ov7670_g_autogain(sd, &ctrl->value);
+	case V4L2_CID_EXPOSURE:
+		return ov7670_g_exp(sd, &ctrl->value);
+	case V4L2_CID_EXPOSURE_AUTO:
+		return ov7670_g_autoexp(sd, &ctrl->value);
+	}
+	return -EINVAL;
+}
+
+static int ov7670_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
+{
+	switch (ctrl->id) {
+	case V4L2_CID_BRIGHTNESS:
+		return ov7670_s_brightness(sd, ctrl->value);
+	case V4L2_CID_CONTRAST:
+		return ov7670_s_contrast(sd, ctrl->value);
+	case V4L2_CID_SATURATION:
+		return ov7670_s_sat(sd, ctrl->value);
+	case V4L2_CID_HUE:
+		return ov7670_s_hue(sd, ctrl->value);
+	case V4L2_CID_VFLIP:
+		return ov7670_s_vflip(sd, ctrl->value);
+	case V4L2_CID_HFLIP:
+		return ov7670_s_hflip(sd, ctrl->value);
+	case V4L2_CID_GAIN:
+		return ov7670_s_gain(sd, ctrl->value);
+	case V4L2_CID_AUTOGAIN:
+		return ov7670_s_autogain(sd, ctrl->value);
+	case V4L2_CID_EXPOSURE:
+		return ov7670_s_exp(sd, ctrl->value);
+	case V4L2_CID_EXPOSURE_AUTO:
+		return ov7670_s_autoexp(sd,
+				(enum v4l2_exposure_auto_type) ctrl->value);
+	}
+	return -EINVAL;
+}
+
+static int ov7670_g_chip_ident(struct v4l2_subdev *sd,
+		struct v4l2_dbg_chip_ident *chip)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_OV7670, 0);
+}
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int ov7670_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	unsigned char val = 0;
+	int ret;
+
+	if (!v4l2_chip_match_i2c_client(client, &reg->match))
+		return -EINVAL;
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	ret = ov7670_read(sd, reg->reg & 0xff, &val);
+	reg->val = val;
+	reg->size = 1;
+	return ret;
+}
+
+static int ov7670_s_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+	if (!v4l2_chip_match_i2c_client(client, &reg->match))
+		return -EINVAL;
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	ov7670_write(sd, reg->reg & 0xff, reg->val & 0xff);
+	return 0;
+}
+#endif
+
+/* ----------------------------------------------------------------------- */
+
+static const struct v4l2_subdev_core_ops ov7670_core_ops = {
+	.g_chip_ident = ov7670_g_chip_ident,
+	.g_ctrl = ov7670_g_ctrl,
+	.s_ctrl = ov7670_s_ctrl,
+	.queryctrl = ov7670_queryctrl,
+	.reset = ov7670_reset,
+	.init = ov7670_init,
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register = ov7670_g_register,
+	.s_register = ov7670_s_register,
+#endif
+};
+
+static const struct v4l2_subdev_video_ops ov7670_video_ops = {
+	.enum_mbus_fmt = ov7670_enum_mbus_fmt,
+	.try_mbus_fmt = ov7670_try_mbus_fmt,
+	.s_mbus_fmt = ov7670_s_mbus_fmt,
+	.s_parm = ov7670_s_parm,
+	.g_parm = ov7670_g_parm,
+	.enum_frameintervals = ov7670_enum_frameintervals,
+	.enum_framesizes = ov7670_enum_framesizes,
+};
+
+static const struct v4l2_subdev_ops ov7670_ops = {
+	.core = &ov7670_core_ops,
+	.video = &ov7670_video_ops,
+};
+
+/* ----------------------------------------------------------------------- */
+
+static int ov7670_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct v4l2_subdev *sd;
+	struct ov7670_info *info;
+	int ret;
+
+	info = kzalloc(sizeof(struct ov7670_info), GFP_KERNEL);
+	if (info == NULL)
+		return -ENOMEM;
+	sd = &info->sd;
+	v4l2_i2c_subdev_init(sd, client, &ov7670_ops);
+
+	info->clock_speed = 30; /* default: a guess */
+	if (client->dev.platform_data) {
+		struct ov7670_config *config = client->dev.platform_data;
+
+		/*
+		 * Must apply configuration before initializing device, because it
+		 * selects I/O method.
+		 */
+		info->min_width = config->min_width;
+		info->min_height = config->min_height;
+		info->use_smbus = config->use_smbus;
+
+		if (config->clock_speed)
+			info->clock_speed = config->clock_speed;
+	}
+
+	/* Make sure it's an ov7670 */
+	ret = ov7670_detect(sd);
+	if (ret) {
+		v4l_dbg(1, debug, client,
+			"chip found @ 0x%x (%s) is not an ov7670 chip.\n",
+			client->addr << 1, client->adapter->name);
+		kfree(info);
+		return ret;
+	}
+	v4l_info(client, "chip found @ 0x%02x (%s)\n",
+			client->addr << 1, client->adapter->name);
+
+	info->fmt = &ov7670_formats[0];
+	info->sat = 128;	/* Review this */
+	info->clkrc = info->clock_speed / 30;
+	return 0;
+}
+
+
+static int ov7670_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *sd = i2c_get_clientdata(client);
+
+	v4l2_device_unregister_subdev(sd);
+	kfree(to_state(sd));
+	return 0;
+}
+
+static const struct i2c_device_id ov7670_id[] = {
+	{ "ov7670", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ov7670_id);
+
+static struct i2c_driver ov7670_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "ov7670",
+	},
+	.probe		= ov7670_probe,
+	.remove		= ov7670_remove,
+	.id_table	= ov7670_id,
+};
+
+module_i2c_driver(ov7670_driver);