V4L/DVB (4798): OmniVision OV7670 driver
This patch adds a V4L2 driver for the OmniVision OV7670 camera.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/ov7670.c b/drivers/media/video/ov7670.c
new file mode 100644
index 0000000..382aa83
--- /dev/null
+++ b/drivers/media/video/ov7670.c
@@ -0,0 +1,1002 @@
+/*
+ * 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.
+ *
+ * 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/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/videodev.h>
+#include <media/v4l2-common.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
+
+/*
+ * 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 */
+
+#define REG_BRIGHT 0x55 /* Brightness */
+#define REG_CONTRAS 0x56 /* Contrast control */
+
+#define REG_GFIX 0x69 /* Fix gain control */
+
+#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 */
+
+
+/*
+ * 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 (15 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|MVFP_MIRROR },
+ { 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 },
+ { 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 },
+
+ /* Not sure if these should be here */
+ { 0xf1, 0x10 }, { 0x0f, 0x1d },
+ { 0x0f, 0x1f },
+
+ { 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" */
+ { 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" */
+ { 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" */
+ { 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 },
+};
+
+
+
+
+/*
+ * 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;
+ return ret;
+}
+
+
+static int ov7670_write(struct i2c_client *c, unsigned char reg,
+ unsigned char value)
+{
+ return i2c_smbus_write_byte_data(c, reg, value);
+}
+
+
+/*
+ * 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;
+}
+
+
+
+
+
+static struct ov7670_format_struct {
+ __u8 *desc;
+ __u32 pixelformat;
+ struct regval_list *regs;
+} ov7670_formats[] = {
+ {
+ .desc = "YUYV 4:2:2",
+ .pixelformat = V4L2_PIX_FMT_YUYV,
+ .regs = ov7670_fmt_yuv422,
+ },
+ {
+ .desc = "RGB 444",
+ .pixelformat = V4L2_PIX_FMT_RGB444,
+ .regs = ov7670_fmt_rgb444,
+ },
+ {
+ .desc = "RGB 565",
+ .pixelformat = V4L2_PIX_FMT_RGB565,
+ .regs = ov7670_fmt_rgb565,
+ },
+ /*
+ * Pretend we do RGB32. This is here on the assumption that the
+ * upper layer will reformat RGB444 appropriately.
+ *
+ * The entire purpose for this thing's existence is to enable easy
+ * display of RGB444 for debugging purposes. It will come out soon.
+ */
+ {
+ .desc = "RGB32 (faked)",
+ .pixelformat = V4L2_PIX_FMT_RGB32,
+ .regs = ov7670_fmt_rgb444,
+ },
+};
+#define N_OV7670_FMTS (sizeof(ov7670_formats)/sizeof(ov7670_formats[0]))
+
+/*
+ * All formats we support are 2 bytes/pixel.
+ */
+#define BYTES_PER_PIXEL 2
+
+/*
+ * Then there is the issue of window sizes. Try to capture the info here.
+ */
+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... */
+/* 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,
+ },
+ /* CIF */
+ {
+ .width = CIF_WIDTH,
+ .height = CIF_HEIGHT,
+ .com7_bit = COM7_FMT_CIF,
+ .hstart = 170, /* Empirically determined */
+ .hstop = 90,
+ .vstart = 14,
+ .vstop = 494,
+ },
+ /* QVGA */
+ {
+ .width = QVGA_WIDTH,
+ .height = QVGA_HEIGHT,
+ .com7_bit = COM7_FMT_QVGA,
+ .hstart = 164, /* Empirically determined */
+ .hstop = 20,
+ .vstart = 14,
+ .vstop = 494,
+ },
+};
+
+#define N_WIN_SIZES (sizeof(ov7670_win_sizes)/sizeof(ov7670_win_sizes[0]))
+
+
+/*
+ * 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)
+ return -EINVAL;
+ if (ret_fmt != NULL)
+ *ret_fmt = ov7670_formats + index;
+ /*
+ * Fields: the OV devices claim to be progressive.
+ */
+ if (pix->field == V4L2_FIELD_ANY)
+ pix->field = V4L2_FIELD_NONE;
+ else if (pix->field != V4L2_FIELD_NONE)
+ return -EINVAL;
+ /*
+ * 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*BYTES_PER_PIXEL;
+ if (pix->pixelformat == V4L2_PIX_FMT_RGB32)
+ pix->bytesperline *= 2;
+ 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;
+ unsigned char com7;
+
+ ret = ov7670_try_fmt(c, 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(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);
+ return 0;
+}
+
+/*
+ * Code for dealing with controls.
+ */
+
+/*
+ * 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, unsigned char value)
+{
+ unsigned char com8;
+ int ret;
+
+ ov7670_read(client, REG_COM8, &com8);
+ com8 &= ~COM8_AEC;
+ ov7670_write(client, REG_COM8, com8);
+ value = ov7670_abs_to_sm(value);
+ ret = ov7670_write(client, REG_BRIGHT, value);
+ return ret;
+}
+
+static int ov7670_q_brightness(struct i2c_client *client, unsigned char *value)
+{
+ int ret;
+ ret = ov7670_read(client, REG_BRIGHT, value);
+ *value = ov7670_sm_to_abs(*value);
+ return ret;
+}
+
+static int ov7670_t_contrast(struct i2c_client *client, unsigned char value)
+{
+ return ov7670_write(client, REG_CONTRAS, value);
+}
+
+static int ov7670_q_contrast(struct i2c_client *client, unsigned char *value)
+{
+ return ov7670_read(client, REG_CONTRAS, value);
+}
+
+static int ov7670_q_hflip(struct i2c_client *client, unsigned char *value)
+{
+ int ret;
+ unsigned char v;
+
+ ret = ov7670_read(client, REG_MVFP, &v);
+ *value = (v & MVFP_MIRROR) == MVFP_MIRROR;
+ return ret;
+}
+
+
+static int ov7670_t_hflip(struct i2c_client *client, unsigned char value)
+{
+ unsigned char v;
+ 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, unsigned char *value)
+{
+ int ret;
+ unsigned char v;
+
+ ret = ov7670_read(client, REG_MVFP, &v);
+ *value = (v & MVFP_FLIP) == MVFP_FLIP;
+ return ret;
+}
+
+
+static int ov7670_t_vflip(struct i2c_client *client, unsigned char value)
+{
+ unsigned char v;
+ 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, unsigned char *value);
+ int (*tweak)(struct i2c_client *c, unsigned char 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_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 (sizeof(ov7670_controls)/sizeof(ov7670_controls[0]))
+
+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;
+ unsigned char v;
+
+ if (octrl == NULL)
+ return -EINVAL;
+ ret = octrl->query(client, &v);
+ if (ret >= 0) {
+ ctrl->value = v;
+ 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);
+
+ if (octrl == NULL)
+ return -EINVAL;
+ return octrl->tweak(client, ctrl->value);
+}
+
+
+
+
+
+
+
+/*
+ * Basic i2c stuff.
+ */
+static struct i2c_driver ov7670_driver;
+
+static int ov7670_attach(struct i2c_adapter *adapter)
+{
+ int ret;
+ struct i2c_client *client;
+
+ printk(KERN_ERR "ov7670 attach, id = %d\n", adapter->id);
+ /*
+ * For now: only deal with adapters we recognize.
+ */
+ if (adapter->id != I2C_HW_SMBUS_CAFE)
+ return -ENODEV;
+
+ printk(KERN_ERR "ov7670 accepting\n");
+ 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");
+ /* Do we need clientdata? */
+
+ /*
+ * Make sure it's an ov7670
+ */
+ ret = ov7670_detect(client);
+ printk(KERN_ERR "detect result is %d\n", ret);
+ if (ret)
+ goto out_free;
+ i2c_attach_client(client);
+ return 0;
+
+ out_free:
+ kfree(client);
+ return ret;
+}
+
+
+static int ov7670_detach(struct i2c_client *client)
+{
+ i2c_detach_client(client);
+ kfree(client);
+ return 0;
+}
+
+
+static int ov7670_command(struct i2c_client *client, unsigned int cmd,
+ void *arg)
+{
+ switch (cmd) {
+ case VIDIOC_INT_G_CHIP_IDENT:
+ * (enum v4l2_chip_ident *) arg = V4L2_IDENT_OV7670;
+ return 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);
+ /* Todo:
+ g/s_parm
+ initialization
+ */
+ }
+ return -EINVAL;
+}
+
+
+
+static struct i2c_driver ov7670_driver = {
+ .driver = {
+ .name = "ov7670",
+ },
+ .id = I2C_DRIVERID_OV7670,
+ .class = I2C_CLASS_CAM_DIGITAL,
+ .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);