/* * 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 #include #include #include #include #include #include #include MODULE_AUTHOR("Jonathan Corbet = 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; } /* * 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]; } ov7670_formats[] = { { .desc = "YUYV 4:2:2", .pixelformat = V4L2_PIX_FMT_YUYV, .regs = ov7670_fmt_yuv422, .cmatrix = { 128, -128, 0, -34, -94, 128 }, }, { .desc = "RGB 444", .pixelformat = V4L2_PIX_FMT_RGB444, .regs = ov7670_fmt_rgb444, .cmatrix = { 179, -179, 0, -61, -176, 228 }, }, { .desc = "RGB 565", .pixelformat = V4L2_PIX_FMT_RGB565, .regs = ov7670_fmt_rgb565, .cmatrix = { 179, -179, 0, -61, -176, 228 }, }, }; #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. */ /* * 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 (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; 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; 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); ret = 0; if (wsize->regs) ret = ov7670_write_array(c, wsize->regs); info->fmt = ovfmt; 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 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; /* * 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, 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; 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; 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; 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; 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; 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; 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 (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; 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; i2c_attach_client(client); 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_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); 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, .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);