ov7670.c

trident tm5600的linux驱动

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.
 */

#if 0  /* This seems unneeded after all, should probably come out */
/*
 * Fetch and store the color matrix.
 */
static int ov7670_get_cmatrix(struct i2c_client *client,
	int matrix[CMATRIX_LEN])
{
	int i, ret;
	unsigned char signbits;

	ret = ov7670_read(client, REG_CMATRIX_SIGN, &signbits);
	for (i = 0; i < CMATRIX_LEN; i++) {
		unsigned char raw;

		ret += ov7670_read(client, REG_CMATRIX_BASE + i, &raw);
		matrix[i] = (int) raw;
		if (signbits & (1 << i))
			matrix[i] *= -1;
	}
	return ret;
}
#endif




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;
}