Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / media / i2c / ov7670.c
diff --git a/kernel/drivers/media/i2c/ov7670.c b/kernel/drivers/media/i2c/ov7670.c
new file mode 100644 (file)
index 0000000..b984752
--- /dev/null
@@ -0,0 +1,1656 @@
+/*
+ * 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-ctrls.h>
+#include <media/v4l2-mediabus.h>
+#include <media/v4l2-image-sizes.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)");
+
+/*
+ * The 7670 sits on i2c with ID 0x42
+ */
+#define OV7670_I2C_ADDR 0x42
+
+#define PLL_FACTOR     4
+
+/* 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_DBLV       0x6b    /* PLL control an debugging */
+#define   DBLV_BYPASS    0x00    /* Bypass PLL */
+#define   DBLV_X4        0x01    /* clock x4 */
+#define   DBLV_X6        0x10    /* clock x6 */
+#define   DBLV_X8        0x11    /* clock x8 */
+
+#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 */
+
+enum ov7670_model {
+       MODEL_OV7670 = 0,
+       MODEL_OV7675,
+};
+
+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 */
+};
+
+struct ov7670_devtype {
+       /* formats supported for each model */
+       struct ov7670_win_size *win_sizes;
+       unsigned int n_win_sizes;
+       /* callbacks for frame rate control */
+       int (*set_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
+       void (*get_framerate)(struct v4l2_subdev *, struct v4l2_fract *);
+};
+
+/*
+ * Information we maintain about a known sensor.
+ */
+struct ov7670_format_struct;  /* coming later */
+struct ov7670_info {
+       struct v4l2_subdev sd;
+       struct v4l2_ctrl_handler hdl;
+       struct {
+               /* gain cluster */
+               struct v4l2_ctrl *auto_gain;
+               struct v4l2_ctrl *gain;
+       };
+       struct {
+               /* exposure cluster */
+               struct v4l2_ctrl *auto_exposure;
+               struct v4l2_ctrl *exposure;
+       };
+       struct {
+               /* saturation/hue cluster */
+               struct v4l2_ctrl *saturation;
+               struct v4l2_ctrl *hue;
+       };
+       struct ov7670_format_struct *fmt;  /* Current format */
+       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 */
+       bool pll_bypass;
+       bool pclk_hb_disable;
+       const struct ov7670_devtype *devtype; /* Device specifics */
+};
+
+static inline struct ov7670_info *to_state(struct v4l2_subdev *sd)
+{
+       return container_of(sd, struct ov7670_info, sd);
+}
+
+static inline struct v4l2_subdev *to_sd(struct v4l2_ctrl *ctrl)
+{
+       return &container_of(ctrl->handler, struct ov7670_info, hdl)->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, 0x48 }, /* 32x 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 {
+       u32 mbus_code;
+       enum v4l2_colorspace colorspace;
+       struct regval_list *regs;
+       int cmatrix[CMATRIX_LEN];
+} ov7670_formats[] = {
+       {
+               .mbus_code      = MEDIA_BUS_FMT_YUYV8_2X8,
+               .colorspace     = V4L2_COLORSPACE_JPEG,
+               .regs           = ov7670_fmt_yuv422,
+               .cmatrix        = { 128, -128, 0, -34, -94, 128 },
+       },
+       {
+               .mbus_code      = MEDIA_BUS_FMT_RGB444_2X8_PADHI_LE,
+               .colorspace     = V4L2_COLORSPACE_SRGB,
+               .regs           = ov7670_fmt_rgb444,
+               .cmatrix        = { 179, -179, 0, -61, -176, 228 },
+       },
+       {
+               .mbus_code      = MEDIA_BUS_FMT_RGB565_2X8_LE,
+               .colorspace     = V4L2_COLORSPACE_SRGB,
+               .regs           = ov7670_fmt_rgb565,
+               .cmatrix        = { 179, -179, 0, -61, -176, 228 },
+       },
+       {
+               .mbus_code      = MEDIA_BUS_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 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,
+       }
+};
+
+static struct ov7670_win_size ov7675_win_sizes[] = {
+       /*
+        * Currently, only VGA is supported. Theoretically it could be possible
+        * to support CIF, QVGA and QCIF too. Taking values for ov7670 as a
+        * base and tweak them empirically could be required.
+        */
+       {
+               .width          = VGA_WIDTH,
+               .height         = VGA_HEIGHT,
+               .com7_bit       = COM7_FMT_VGA,
+               .hstart         = 158,  /* These values from */
+               .hstop          =  14,  /* Omnivision */
+               .vstart         =  14,  /* Empirically determined */
+               .vstop          = 494,
+               .regs           = NULL,
+       }
+};
+
+static void ov7675_get_framerate(struct v4l2_subdev *sd,
+                                struct v4l2_fract *tpf)
+{
+       struct ov7670_info *info = to_state(sd);
+       u32 clkrc = info->clkrc;
+       int pll_factor;
+
+       if (info->pll_bypass)
+               pll_factor = 1;
+       else
+               pll_factor = PLL_FACTOR;
+
+       clkrc++;
+       if (info->fmt->mbus_code == MEDIA_BUS_FMT_SBGGR8_1X8)
+               clkrc = (clkrc >> 1);
+
+       tpf->numerator = 1;
+       tpf->denominator = (5 * pll_factor * info->clock_speed) /
+                       (4 * clkrc);
+}
+
+static int ov7675_set_framerate(struct v4l2_subdev *sd,
+                                struct v4l2_fract *tpf)
+{
+       struct ov7670_info *info = to_state(sd);
+       u32 clkrc;
+       int pll_factor;
+       int ret;
+
+       /*
+        * The formula is fps = 5/4*pixclk for YUV/RGB and
+        * fps = 5/2*pixclk for RAW.
+        *
+        * pixclk = clock_speed / (clkrc + 1) * PLLfactor
+        *
+        */
+       if (info->pll_bypass) {
+               pll_factor = 1;
+               ret = ov7670_write(sd, REG_DBLV, DBLV_BYPASS);
+       } else {
+               pll_factor = PLL_FACTOR;
+               ret = ov7670_write(sd, REG_DBLV, DBLV_X4);
+       }
+       if (ret < 0)
+               return ret;
+
+       if (tpf->numerator == 0 || tpf->denominator == 0) {
+               clkrc = 0;
+       } else {
+               clkrc = (5 * pll_factor * info->clock_speed * tpf->numerator) /
+                       (4 * tpf->denominator);
+               if (info->fmt->mbus_code == MEDIA_BUS_FMT_SBGGR8_1X8)
+                       clkrc = (clkrc << 1);
+               clkrc--;
+       }
+
+       /*
+        * The datasheet claims that clkrc = 0 will divide the input clock by 1
+        * but we've checked with an oscilloscope that it divides by 2 instead.
+        * So, if clkrc = 0 just bypass the divider.
+        */
+       if (clkrc <= 0)
+               clkrc = CLK_EXT;
+       else if (clkrc > CLK_SCALE)
+               clkrc = CLK_SCALE;
+       info->clkrc = clkrc;
+
+       /* Recalculate frame rate */
+       ov7675_get_framerate(sd, tpf);
+
+       ret = ov7670_write(sd, REG_CLKRC, info->clkrc);
+       if (ret < 0)
+               return ret;
+
+       return ov7670_write(sd, REG_DBLV, DBLV_X4);
+}
+
+static void ov7670_get_framerate_legacy(struct v4l2_subdev *sd,
+                                struct v4l2_fract *tpf)
+{
+       struct ov7670_info *info = to_state(sd);
+
+       tpf->numerator = 1;
+       tpf->denominator = info->clock_speed;
+       if ((info->clkrc & CLK_EXT) == 0 && (info->clkrc & CLK_SCALE) > 1)
+               tpf->denominator /= (info->clkrc & CLK_SCALE);
+}
+
+static int ov7670_set_framerate_legacy(struct v4l2_subdev *sd,
+                                       struct v4l2_fract *tpf)
+{
+       struct ov7670_info *info = to_state(sd);
+       int div;
+
+       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);
+}
+
+/*
+ * 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,
+                                       u32 *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, i;
+       struct ov7670_win_size *wsize;
+       struct ov7670_info *info = to_state(sd);
+       unsigned int n_win_sizes = info->devtype->n_win_sizes;
+       unsigned int win_sizes_limit = n_win_sizes;
+
+       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;
+
+       /*
+        * Don't consider values that don't match min_height and min_width
+        * constraints.
+        */
+       if (info->min_width || info->min_height)
+               for (i = 0; i < n_win_sizes; i++) {
+                       wsize = info->devtype->win_sizes + i;
+
+                       if (wsize->width < info->min_width ||
+                               wsize->height < info->min_height) {
+                               win_sizes_limit = i;
+                               break;
+                       }
+               }
+       /*
+        * Round requested image size down to the nearest
+        * we support, but not below the smallest.
+        */
+       for (wsize = info->devtype->win_sizes;
+            wsize < info->devtype->win_sizes + win_sizes_limit; wsize++)
+               if (fmt->width >= wsize->width && fmt->height >= wsize->height)
+                       break;
+       if (wsize >= info->devtype->win_sizes + win_sizes_limit)
+               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;
+       info->devtype->get_framerate(sd, &cp->timeperframe);
+
+       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);
+
+       if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               return -EINVAL;
+       if (cp->extendedmode != 0)
+               return -EINVAL;
+
+       return info->devtype->set_framerate(sd, tpf);
+}
+
+
+/*
+ * 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_frame_interval(struct v4l2_subdev *sd,
+                                     struct v4l2_subdev_pad_config *cfg,
+                                     struct v4l2_subdev_frame_interval_enum *fie)
+{
+       if (fie->pad)
+               return -EINVAL;
+       if (fie->index >= ARRAY_SIZE(ov7670_frame_rates))
+               return -EINVAL;
+       fie->interval.numerator = 1;
+       fie->interval.denominator = ov7670_frame_rates[fie->index];
+       return 0;
+}
+
+/*
+ * Frame size enumeration
+ */
+static int ov7670_enum_frame_size(struct v4l2_subdev *sd,
+                                 struct v4l2_subdev_pad_config *cfg,
+                                 struct v4l2_subdev_frame_size_enum *fse)
+{
+       struct ov7670_info *info = to_state(sd);
+       int i;
+       int num_valid = -1;
+       __u32 index = fse->index;
+       unsigned int n_win_sizes = info->devtype->n_win_sizes;
+
+       if (fse->pad)
+               return -EINVAL;
+
+       /*
+        * 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 = &info->devtype->win_sizes[i];
+               if (info->min_width && win->width < info->min_width)
+                       continue;
+               if (info->min_height && win->height < info->min_height)
+                       continue;
+               if (index == ++num_valid) {
+                       fse->min_width = fse->max_width = win->width;
+                       fse->min_height = fse->max_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 sat, int hue)
+{
+       int i;
+       /*
+        * Apply the current saturation setting first.
+        */
+       for (i = 0; i < CMATRIX_LEN; i++)
+               matrix[i] = (info->fmt->cmatrix[i] * sat) >> 7;
+       /*
+        * Then, if need be, rotate the hue value.
+        */
+       if (hue != 0) {
+               int sinth, costh, tmpmatrix[CMATRIX_LEN];
+
+               memcpy(tmpmatrix, matrix, CMATRIX_LEN*sizeof(int));
+               sinth = ov7670_sine(hue);
+               costh = ov7670_cosine(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_hue(struct v4l2_subdev *sd, int sat, int hue)
+{
+       struct ov7670_info *info = to_state(sd);
+       int matrix[CMATRIX_LEN];
+       int ret;
+
+       ov7670_calc_cmatrix(info, matrix, sat, hue);
+       ret = ov7670_store_cmatrix(sd, matrix);
+       return ret;
+}
+
+
+/*
+ * Some weird registers seem to store values in a sign/magnitude format!
+ */
+
+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_s_contrast(struct v4l2_subdev *sd, int value)
+{
+       return ov7670_write(sd, REG_CONTRAS, (unsigned char) value);
+}
+
+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_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_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;
+}
+
+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_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_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
+{
+       struct v4l2_subdev *sd = to_sd(ctrl);
+       struct ov7670_info *info = to_state(sd);
+
+       switch (ctrl->id) {
+       case V4L2_CID_AUTOGAIN:
+               return ov7670_g_gain(sd, &info->gain->val);
+       }
+       return -EINVAL;
+}
+
+static int ov7670_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+       struct v4l2_subdev *sd = to_sd(ctrl);
+       struct ov7670_info *info = to_state(sd);
+
+       switch (ctrl->id) {
+       case V4L2_CID_BRIGHTNESS:
+               return ov7670_s_brightness(sd, ctrl->val);
+       case V4L2_CID_CONTRAST:
+               return ov7670_s_contrast(sd, ctrl->val);
+       case V4L2_CID_SATURATION:
+               return ov7670_s_sat_hue(sd,
+                               info->saturation->val, info->hue->val);
+       case V4L2_CID_VFLIP:
+               return ov7670_s_vflip(sd, ctrl->val);
+       case V4L2_CID_HFLIP:
+               return ov7670_s_hflip(sd, ctrl->val);
+       case V4L2_CID_AUTOGAIN:
+               /* Only set manual gain if auto gain is not explicitly
+                  turned on. */
+               if (!ctrl->val) {
+                       /* ov7670_s_gain turns off auto gain */
+                       return ov7670_s_gain(sd, info->gain->val);
+               }
+               return ov7670_s_autogain(sd, ctrl->val);
+       case V4L2_CID_EXPOSURE_AUTO:
+               /* Only set manual exposure if auto exposure is not explicitly
+                  turned on. */
+               if (ctrl->val == V4L2_EXPOSURE_MANUAL) {
+                       /* ov7670_s_exp turns off auto exposure */
+                       return ov7670_s_exp(sd, info->exposure->val);
+               }
+               return ov7670_s_autoexp(sd, ctrl->val);
+       }
+       return -EINVAL;
+}
+
+static const struct v4l2_ctrl_ops ov7670_ctrl_ops = {
+       .s_ctrl = ov7670_s_ctrl,
+       .g_volatile_ctrl = ov7670_g_volatile_ctrl,
+};
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int ov7670_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
+{
+       unsigned char val = 0;
+       int ret;
+
+       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, const struct v4l2_dbg_register *reg)
+{
+       ov7670_write(sd, reg->reg & 0xff, reg->val & 0xff);
+       return 0;
+}
+#endif
+
+/* ----------------------------------------------------------------------- */
+
+static const struct v4l2_subdev_core_ops ov7670_core_ops = {
+       .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,
+};
+
+static const struct v4l2_subdev_pad_ops ov7670_pad_ops = {
+       .enum_frame_interval = ov7670_enum_frame_interval,
+       .enum_frame_size = ov7670_enum_frame_size,
+};
+
+static const struct v4l2_subdev_ops ov7670_ops = {
+       .core = &ov7670_core_ops,
+       .video = &ov7670_video_ops,
+       .pad = &ov7670_pad_ops,
+};
+
+/* ----------------------------------------------------------------------- */
+
+static const struct ov7670_devtype ov7670_devdata[] = {
+       [MODEL_OV7670] = {
+               .win_sizes = ov7670_win_sizes,
+               .n_win_sizes = ARRAY_SIZE(ov7670_win_sizes),
+               .set_framerate = ov7670_set_framerate_legacy,
+               .get_framerate = ov7670_get_framerate_legacy,
+       },
+       [MODEL_OV7675] = {
+               .win_sizes = ov7675_win_sizes,
+               .n_win_sizes = ARRAY_SIZE(ov7675_win_sizes),
+               .set_framerate = ov7675_set_framerate,
+               .get_framerate = ov7675_get_framerate,
+       },
+};
+
+static int ov7670_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+       struct v4l2_fract tpf;
+       struct v4l2_subdev *sd;
+       struct ov7670_info *info;
+       int ret;
+
+       info = devm_kzalloc(&client->dev, sizeof(*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;
+
+               /*
+                * It should be allowed for ov7670 too when it is migrated to
+                * the new frame rate formula.
+                */
+               if (config->pll_bypass && id->driver_data != MODEL_OV7670)
+                       info->pll_bypass = true;
+
+               if (config->pclk_hb_disable)
+                       info->pclk_hb_disable = true;
+       }
+
+       /* 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);
+               return ret;
+       }
+       v4l_info(client, "chip found @ 0x%02x (%s)\n",
+                       client->addr << 1, client->adapter->name);
+
+       info->devtype = &ov7670_devdata[id->driver_data];
+       info->fmt = &ov7670_formats[0];
+       info->clkrc = 0;
+
+       /* Set default frame rate to 30 fps */
+       tpf.numerator = 1;
+       tpf.denominator = 30;
+       info->devtype->set_framerate(sd, &tpf);
+
+       if (info->pclk_hb_disable)
+               ov7670_write(sd, REG_COM10, COM10_PCLK_HB);
+
+       v4l2_ctrl_handler_init(&info->hdl, 10);
+       v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
+       v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_CONTRAST, 0, 127, 1, 64);
+       v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_VFLIP, 0, 1, 1, 0);
+       v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_HFLIP, 0, 1, 1, 0);
+       info->saturation = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_SATURATION, 0, 256, 1, 128);
+       info->hue = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_HUE, -180, 180, 5, 0);
+       info->gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_GAIN, 0, 255, 1, 128);
+       info->auto_gain = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
+       info->exposure = v4l2_ctrl_new_std(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_EXPOSURE, 0, 65535, 1, 500);
+       info->auto_exposure = v4l2_ctrl_new_std_menu(&info->hdl, &ov7670_ctrl_ops,
+                       V4L2_CID_EXPOSURE_AUTO, V4L2_EXPOSURE_MANUAL, 0,
+                       V4L2_EXPOSURE_AUTO);
+       sd->ctrl_handler = &info->hdl;
+       if (info->hdl.error) {
+               int err = info->hdl.error;
+
+               v4l2_ctrl_handler_free(&info->hdl);
+               return err;
+       }
+       /*
+        * We have checked empirically that hw allows to read back the gain
+        * value chosen by auto gain but that's not the case for auto exposure.
+        */
+       v4l2_ctrl_auto_cluster(2, &info->auto_gain, 0, true);
+       v4l2_ctrl_auto_cluster(2, &info->auto_exposure,
+                              V4L2_EXPOSURE_MANUAL, false);
+       v4l2_ctrl_cluster(2, &info->saturation);
+       v4l2_ctrl_handler_setup(&info->hdl);
+
+       return 0;
+}
+
+
+static int ov7670_remove(struct i2c_client *client)
+{
+       struct v4l2_subdev *sd = i2c_get_clientdata(client);
+       struct ov7670_info *info = to_state(sd);
+
+       v4l2_device_unregister_subdev(sd);
+       v4l2_ctrl_handler_free(&info->hdl);
+       return 0;
+}
+
+static const struct i2c_device_id ov7670_id[] = {
+       { "ov7670", MODEL_OV7670 },
+       { "ov7675", MODEL_OV7675 },
+       { }
+};
+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);