/*
* 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/delay.h>
#include <linux/videodev2.h>
#include <media/v4l2-common.h>
#include <media/v4l2-chip-ident.h>
#include <linux/i2c.h>
MODULE_AUTHOR("Jonathan Corbet <corbet@lwn.net>");
MODULE_DESCRIPTION("A low-level driver for OmniVision ov7670 sensors");
MODULE_LICENSE("GPL");
/*
* 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
/*
* Our nominal (default) frame rate.
*/
#define OV7670_FRAME_RATE 30
/*
* 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 ov7670_format_struct *fmt; /* Current format */
unsigned char sat; /* Saturation value */
int hue; /* Hue value */
};
/*
* 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 },
{ 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 },
{ 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, 0x40 }, /* Magic reserved bit */
{ 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.
*/
static int ov7670_read(struct i2c_client *c, unsigned char reg,
unsigned char *value)
{
int ret;
ret = i2c_smbus_read_byte_data(c, reg);
if (ret >= 0) {
*value = (unsigned char) ret;
ret = 0;
}
return ret;
}
static int ov7670_write(struct i2c_client *c, unsigned char reg,
unsigned char value)
{
int ret = i2c_smbus_write_byte_data(c, reg, value);
if (reg == REG_COM7 && (value & COM7_RESET))
msleep(2); /* Wait for reset to run */
return ret;
}
/*
* Write a list of register settings; ff/ff stops the process.
*/
static int ov7670_write_array(struct i2c_client *c, struct regval_list *vals)
{
while (vals->reg_num != 0xff || vals->value != 0xff) {
int ret = ov7670_write(c, vals->reg_num, vals->value);
if (ret < 0)
return ret;
vals++;
}
return 0;
}
/*
* Stuff that knows about the sensor.
*/
static void ov7670_reset(struct i2c_client *client)
{
ov7670_write(client, REG_COM7, COM7_RESET);
msleep(1);
}
static int ov7670_init(struct i2c_client *client)
{
return ov7670_write_array(client, ov7670_default_regs);
}
static int ov7670_detect(struct i2c_client *client)
{
unsigned char v;
int ret;
ret = ov7670_init(client);
if (ret < 0)
return ret;
ret = ov7670_read(client, REG_MIDH, &v);
if (ret < 0)
return ret;
if (v != 0x7f) /* OV manuf. id. */
return -ENODEV;
ret = ov7670_read(client, 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(client, REG_PID, &v);
if (ret < 0)
return ret;
if (v != 0x76) /* PID + VER = 0x76 / 0x73 */
return -ENODEV;
ret = ov7670_read(client, 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 nubmers come from OmniVision.
*/
static struct ov7670_format_struct {
__u8 *desc;
__u32 pixelformat;
struct regval_list *regs;
int cmatrix[CMATRIX_LEN];
int bpp; /* Bytes per pixel */
} ov7670_formats[] = {
{
.desc = "YUYV 4:2:2",
.pixelformat = V4L2_PIX_FMT_YUYV,
.regs = ov7670_fmt_yuv422,
.cmatrix = { 128, -128, 0, -34, -94, 128 },
.bpp = 2,
},
{
.desc = "RGB 444",
.pixelformat = V4L2_PIX_FMT_RGB444,
.regs = ov7670_fmt_rgb444,
.cmatrix = { 179, -179, 0, -61, -176, 228 },
.bpp = 2,
},
{
.desc = "RGB 565",
.pixelformat = V4L2_PIX_FMT_RGB565,
.regs = ov7670_fmt_rgb565,
.cmatrix = { 179, -179, 0, -61, -176, 228 },
.bpp = 2,
},
{
.desc = "Raw RGB Bayer",
.pixelformat = V4L2_PIX_FMT_SBGGR8,
.regs = ov7670_fmt_raw,
.cmatrix = { 0, 0, 0, 0, 0, 0 },
.bpp = 1
},
};
#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 = 164, /* Empirically determined */
.hstop = 20,
.vstart = 14,
.vstop = 494,
.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 i2c_client *client, 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(client, REG_HSTART, (hstart >> 3) & 0xff);
ret += ov7670_write(client, REG_HSTOP, (hstop >> 3) & 0xff);
ret += ov7670_read(client, REG_HREF, &v);
v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
msleep(10);
ret += ov7670_write(client, REG_HREF, v);
/*
* Vertical: similar arrangement, but only 10 bits.
*/
ret += ov7670_write(client, REG_VSTART, (vstart >> 2) & 0xff);
ret += ov7670_write(client, REG_VSTOP, (vstop >> 2) & 0xff);
ret += ov7670_read(client, REG_VREF, &v);
v = (v & 0xf0) | ((vstop & 0x3) << 2) | (vstart & 0x3);
msleep(10);
ret += ov7670_write(client, REG_VREF, v);
return ret;
}
static int ov7670_enum_fmt(struct i2c_client *c, struct v4l2_fmtdesc *fmt)
{
struct ov7670_format_struct *ofmt;
if (fmt->index >= N_OV7670_FMTS)
return -EINVAL;
ofmt = ov7670_formats + fmt->index;
fmt->flags = 0;
strcpy(fmt->description, ofmt->desc);
fmt->pixelformat = ofmt->pixelformat;
return 0;
}
static int ov7670_try_fmt(struct i2c_client *c, struct v4l2_format *fmt,
struct ov7670_format_struct **ret_fmt,
struct ov7670_win_size **ret_wsize)
{
int index;
struct ov7670_win_size *wsize;
struct v4l2_pix_format *pix = &fmt->fmt.pix;
for (index = 0; index < N_OV7670_FMTS; index++)
if (ov7670_formats[index].pixelformat == pix->pixelformat)
break;
if (index >= N_OV7670_FMTS) {
/* default to first format */
index = 0;
pix->pixelformat = ov7670_formats[0].pixelformat;
}
if (ret_fmt != NULL)
*ret_fmt = ov7670_formats + index;
/*
* Fields: the OV devices claim to be progressive.
*/
pix->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 (pix->width >= wsize->width && pix->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.
*/
pix->width = wsize->width;
pix->height = wsize->height;
pix->bytesperline = pix->width*ov7670_formats[index].bpp;
pix->sizeimage = pix->height*pix->bytesperline;
return 0;
}
/*
* Set a format.
*/
static int ov7670_s_fmt(struct i2c_client *c, struct v4l2_format *fmt)
{
int ret;
struct ov7670_format_struct *ovfmt;
struct ov7670_win_size *wsize;
struct ov7670_info *info = i2c_get_clientdata(c);
unsigned char com7, clkrc;
ret = ov7670_try_fmt(c, fmt, &ovfmt, &wsize);
if (ret)
return ret;
/*
* HACK: if we're running rgb565 we need to grab then rewrite
* CLKRC. If we're *not*, however, then rewriting clkrc hoses
* the colors.
*/
if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565) {
ret = ov7670_read(c, REG_CLKRC, &clkrc);
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(c, REG_COM7, com7);
/*
* Now write the rest of the array. Also store start/stops
*/
ov7670_write_array(c, ovfmt->regs + 1);
ov7670_set_hw(c, wsize->hstart, wsize->hstop, wsize->vstart,
wsize->vstop);
ret = 0;
if (wsize->regs)
ret = ov7670_write_array(c, wsize->regs);
info->fmt = ovfmt;
if (fmt->fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565 && ret == 0)
ret = ov7670_write(c, REG_CLKRC, clkrc);
return ret;
}
/*
* 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 i2c_client *c, struct v4l2_streamparm *parms)
{
struct v4l2_captureparm *cp = &parms->parm.capture;
unsigned char clkrc;
int ret;
if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
return -EINVAL;
ret = ov7670_read(c, REG_CLKRC, &clkrc);
if (ret < 0)
return ret;
memset(cp, 0, sizeof(struct v4l2_captureparm));
cp->capability = V4L2_CAP_TIMEPERFRAME;
cp->timeperframe.numerator = 1;
cp->timeperframe.denominator = OV7670_FRAME_RATE;
if ((clkrc & CLK_EXT) == 0 && (clkrc & CLK_SCALE) > 1)
cp->timeperframe.denominator /= (clkrc & CLK_SCALE);
return 0;
}
static int ov7670_s_parm(struct i2c_client *c, struct v4l2_streamparm *parms)
{
struct v4l2_captureparm *cp = &parms->parm.capture;
struct v4l2_fract *tpf = &cp->timeperframe;
unsigned char clkrc;
int ret, div;
if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
return -EINVAL;
if (cp->extendedmode != 0)
return -EINVAL;
/*
* CLKRC has a reserved bit, so let's preserve it.
*/
ret = ov7670_read(c, REG_CLKRC, &clkrc);
if (ret < 0)
return ret;
if (tpf->numerator == 0 || tpf->denominator == 0)
div = 1; /* Reset to full rate */
else
div = (tpf->numerator*OV7670_FRAME_RATE)/tpf->denominator;
if (div == 0)
div = 1;
else if (div > CLK_SCALE)
div = CLK_SCALE;
clkrc = (clkrc & 0x80) | div;
tpf->numerator = 1;
tpf->denominator = OV7670_FRAME_RATE/div;
return ov7670_write(c, REG_CLKRC, clkrc);
}
/*
* Code for dealing with controls.
*/
static int ov7670_store_cmatrix(struct i2c_client *client,
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(client, 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(client, REG_CMATRIX_BASE + i, raw);
}
ret += ov7670_write(client, 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_t_sat(struct i2c_client *client, int value)
{
struct ov7670_info *info = i2c_get_clientdata(client);
int matrix[CMATRIX_LEN];
int ret;
info->sat = value;
ov7670_calc_cmatrix(info, matrix);
ret = ov7670_store_cmatrix(client, matrix);
return ret;
}
static int ov7670_q_sat(struct i2c_client *client, __s32 *value)
{
struct ov7670_info *info = i2c_get_clientdata(client);
*value = info->sat;
return 0;
}
static int ov7670_t_hue(struct i2c_client *client, int value)
{
struct ov7670_info *info = i2c_get_clientdata(client);
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(client, matrix);
return ret;
}
static int ov7670_q_hue(struct i2c_client *client, __s32 *value)
{
struct ov7670_info *info = i2c_get_clientdata(client);
*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;
else
return 128 - (v & 0x7f);
}
static unsigned char ov7670_abs_to_sm(unsigned char v)
{
if (v > 127)
return v & 0x7f;
else
return (128 - v) | 0x80;
}
static int ov7670_t_brightness(struct i2c_client *client, int value)
{
unsigned char com8 = 0, v;
int ret;
ov7670_read(client, REG_COM8, &com8);
com8 &= ~COM8_AEC;
ov7670_write(client, REG_COM8, com8);
v = ov7670_abs_to_sm(value);
ret = ov7670_write(client, REG_BRIGHT, v);
return ret;
}
static int ov7670_q_brightness(struct i2c_client *client, __s32 *value)
{
unsigned char v = 0;
int ret = ov7670_read(client, REG_BRIGHT, &v);
*value = ov7670_sm_to_abs(v);
return ret;
}
static int ov7670_t_contrast(struct i2c_client *client, int value)
{
return ov7670_write(client, REG_CONTRAS, (unsigned char) value);
}
static int ov7670_q_contrast(struct i2c_client *client, __s32 *value)
{
unsigned char v = 0;
int ret = ov7670_read(client, REG_CONTRAS, &v);
*value = v;
return ret;
}
static int ov7670_q_hflip(struct i2c_client *client, __s32 *value)
{
int ret;
unsigned char v = 0;
ret = ov7670_read(client, REG_MVFP, &v);
*value = (v & MVFP_MIRROR) == MVFP_MIRROR;
return ret;
}
static int ov7670_t_hflip(struct i2c_client *client, int value)
{
unsigned char v = 0;
int ret;
ret = ov7670_read(client, REG_MVFP, &v);
if (value)
v |= MVFP_MIRROR;
else
v &= ~MVFP_MIRROR;
msleep(10); /* FIXME */
ret += ov7670_write(client, REG_MVFP, v);
return ret;
}
static int ov7670_q_vflip(struct i2c_client *client, __s32 *value)
{
int ret;
unsigned char v = 0;
ret = ov7670_read(client, REG_MVFP, &v);
*value = (v & MVFP_FLIP) == MVFP_FLIP;
return ret;
}
static int ov7670_t_vflip(struct i2c_client *client, int value)
{
unsigned char v = 0;
int ret;
ret = ov7670_read(client, REG_MVFP, &v);
if (value)
v |= MVFP_FLIP;
else
v &= ~MVFP_FLIP;
msleep(10); /* FIXME */
ret += ov7670_write(client, REG_MVFP, v);
return ret;
}
static struct ov7670_control {
struct v4l2_queryctrl qc;
int (*query)(struct i2c_client *c, __s32 *value);
int (*tweak)(struct i2c_client *c, int value);
} ov7670_controls[] =
{
{
.qc = {
.id = V4L2_CID_BRIGHTNESS,
.type = V4L2_CTRL_TYPE_INTEGER,
.name = "Brightness",
.minimum = 0,
.maximum = 255,
.step = 1,
.default_value = 0x80,
.flags = V4L2_CTRL_FLAG_SLIDER
},
.tweak = ov7670_t_brightness,
.query = ov7670_q_brightness,
},
{
.qc = {
.id = V4L2_CID_CONTRAST,
.type = V4L2_CTRL_TYPE_INTEGER,
.name = "Contrast",
.minimum = 0,
.maximum = 127,
.step = 1,
.default_value = 0x40, /* XXX ov7670 spec */
.flags = V4L2_CTRL_FLAG_SLIDER
},
.tweak = ov7670_t_contrast,
.query = ov7670_q_contrast,
},
{
.qc = {
.id = V4L2_CID_SATURATION,
.type = V4L2_CTRL_TYPE_INTEGER,
.name = "Saturation",
.minimum = 0,
.maximum = 256,
.step = 1,
.default_value = 0x80,
.flags = V4L2_CTRL_FLAG_SLIDER
},
.tweak = ov7670_t_sat,
.query = ov7670_q_sat,
},
{
.qc = {
.id = V4L2_CID_HUE,
.type = V4L2_CTRL_TYPE_INTEGER,
.name = "HUE",
.minimum = -180,
.maximum = 180,
.step = 5,
.default_value = 0,
.flags = V4L2_CTRL_FLAG_SLIDER
},
.tweak = ov7670_t_hue,
.query = ov7670_q_hue,
},
{
.qc = {
.id = V4L2_CID_VFLIP,
.type = V4L2_CTRL_TYPE_BOOLEAN,
.name = "Vertical flip",
.minimum = 0,
.maximum = 1,
.step = 1,
.default_value = 0,
},
.tweak = ov7670_t_vflip,
.query = ov7670_q_vflip,
},
{
.qc = {
.id = V4L2_CID_HFLIP,
.type = V4L2_CTRL_TYPE_BOOLEAN,
.name = "Horizontal mirror",
.minimum = 0,
.maximum = 1,
.step = 1,
.default_value = 0,
},
.tweak = ov7670_t_hflip,
.query = ov7670_q_hflip,
},
};
#define N_CONTROLS (ARRAY_SIZE(ov7670_controls))
static struct ov7670_control *ov7670_find_control(__u32 id)
{
int i;
for (i = 0; i < N_CONTROLS; i++)
if (ov7670_controls[i].qc.id == id)
return ov7670_controls + i;
return NULL;
}
static int ov7670_queryctrl(struct i2c_client *client,
struct v4l2_queryctrl *qc)
{
struct ov7670_control *ctrl = ov7670_find_control(qc->id);
if (ctrl == NULL)
return -EINVAL;
*qc = ctrl->qc;
return 0;
}
static int ov7670_g_ctrl(struct i2c_client *client, struct v4l2_control *ctrl)
{
struct ov7670_control *octrl = ov7670_find_control(ctrl->id);
int ret;
if (octrl == NULL)
return -EINVAL;
ret = octrl->query(client, &ctrl->value);
if (ret >= 0)
return 0;
return ret;
}
static int ov7670_s_ctrl(struct i2c_client *client, struct v4l2_control *ctrl)
{
struct ov7670_control *octrl = ov7670_find_control(ctrl->id);
int ret;
if (octrl == NULL)
return -EINVAL;
ret = octrl->tweak(client, ctrl->value);
if (ret >= 0)
return 0;
return ret;
}
/*
* Basic i2c stuff.
*/
static struct i2c_driver ov7670_driver;
static int ov7670_attach(struct i2c_adapter *adapter)
{
int ret;
struct i2c_client *client;
struct ov7670_info *info;
/*
* For now: only deal with adapters we recognize.
*/
if (adapter->id != I2C_HW_SMBUS_CAFE)
return -ENODEV;
client = kzalloc(sizeof (struct i2c_client), GFP_KERNEL);
if (! client)
return -ENOMEM;
client->adapter = adapter;
client->addr = OV7670_I2C_ADDR;
client->driver = &ov7670_driver,
strcpy(client->name, "OV7670");
/*
* Set up our info structure.
*/
info = kzalloc(sizeof (struct ov7670_info), GFP_KERNEL);
if (! info) {
ret = -ENOMEM;
goto out_free;
}
info->fmt = &ov7670_formats[0];
info->sat = 128; /* Review this */
i2c_set_clientdata(client, info);
/*
* Make sure it's an ov7670
*/
ret = ov7670_detect(client);
if (ret)
goto out_free_info;
ret = i2c_attach_client(client);
if (ret)
goto out_free_info;
return 0;
out_free_info:
kfree(info);
out_free:
kfree(client);
return ret;
}
static int ov7670_detach(struct i2c_client *client)
{
i2c_detach_client(client);
kfree(i2c_get_clientdata(client));
kfree(client);
return 0;
}
static int ov7670_command(struct i2c_client *client, unsigned int cmd,
void *arg)
{
switch (cmd) {
case VIDIOC_DBG_G_CHIP_IDENT:
return v4l2_chip_ident_i2c_client(client, arg, V4L2_IDENT_OV7670, 0);
case VIDIOC_INT_RESET:
ov7670_reset(client);
return 0;
case VIDIOC_INT_INIT:
return ov7670_init(client);
case VIDIOC_ENUM_FMT:
return ov7670_enum_fmt(client, (struct v4l2_fmtdesc *) arg);
case VIDIOC_TRY_FMT:
return ov7670_try_fmt(client, (struct v4l2_format *) arg, NULL, NULL);
case VIDIOC_S_FMT:
return ov7670_s_fmt(client, (struct v4l2_format *) arg);
case VIDIOC_QUERYCTRL:
return ov7670_queryctrl(client, (struct v4l2_queryctrl *) arg);
case VIDIOC_S_CTRL:
return ov7670_s_ctrl(client, (struct v4l2_control *) arg);
case VIDIOC_G_CTRL:
return ov7670_g_ctrl(client, (struct v4l2_control *) arg);
case VIDIOC_S_PARM:
return ov7670_s_parm(client, (struct v4l2_streamparm *) arg);
case VIDIOC_G_PARM:
return ov7670_g_parm(client, (struct v4l2_streamparm *) arg);
}
return -EINVAL;
}
static struct i2c_driver ov7670_driver = {
.driver = {
.name = "ov7670",
},
.id = I2C_DRIVERID_OV7670,
.attach_adapter = ov7670_attach,
.detach_client = ov7670_detach,
.command = ov7670_command,
};
/*
* Module initialization
*/
static int __init ov7670_mod_init(void)
{
printk(KERN_NOTICE "OmniVision ov7670 sensor driver, at your service\n");
return i2c_add_driver(&ov7670_driver);
}
static void __exit ov7670_mod_exit(void)
{
i2c_del_driver(&ov7670_driver);
}
module_init(ov7670_mod_init);
module_exit(ov7670_mod_exit);
