ov511.c

ov511.c是linux下的wabcam的驱动

	char dirname[10];

	if (!ov511_proc_entry || !ov)
		return;

	/* Create per-device directory */
	snprintf(dirname, 10, "%d", ov->vdev.minor);
	PDEBUG(4, "creating /proc/video/ov511/%s/", dirname);
	ov->proc_devdir = create_proc_entry(dirname, S_IFDIR, ov511_proc_entry);
	if (!ov->proc_devdir)
		return;
	ov->proc_devdir->owner = THIS_MODULE;

	/* Create "info" entry (human readable device information) */
	PDEBUG(4, "creating /proc/video/ov511/%s/info", dirname);
	ov->proc_info = create_proc_read_entry("info", S_IFREG|S_IRUGO|S_IWUSR,
		ov->proc_devdir, ov511_read_proc_info, ov);
	if (!ov->proc_info)
		return;
	ov->proc_info->owner = THIS_MODULE;

	/* Don't create it if old snapshot mode on (would cause race cond.) */
	if (!snapshot) {
		/* Create "button" entry (snapshot button status) */
		PDEBUG(4, "creating /proc/video/ov511/%s/button", dirname);
		ov->proc_button = create_proc_read_entry("button",
			S_IFREG|S_IRUGO|S_IWUSR, ov->proc_devdir,
			ov511_read_proc_button, ov);
		if (!ov->proc_button)
			return;
		ov->proc_button->owner = THIS_MODULE;
	}

	/* Create "control" entry (ioctl() interface) */
	PDEBUG(4, "creating /proc/video/ov511/%s/control", dirname);
	lock_kernel();
	ov->proc_control = create_proc_entry("control",	S_IFREG|S_IRUGO|S_IWUSR,
		ov->proc_devdir);
	if (!ov->proc_control) {
		unlock_kernel();
		return;
	}
	ov->proc_control->owner = THIS_MODULE;
	ov->proc_control->data = ov;
	ov->proc_control->proc_fops = &ov511_control_fops;
	unlock_kernel();
}

static void
destroy_proc_ov511_cam(struct usb_ov511 *ov)
{
	char dirname[10];

	if (!ov || !ov->proc_devdir)
		return;

	snprintf(dirname, 10, "%d", ov->vdev.minor);

	/* Destroy "control" entry */
	if (ov->proc_control) {
		PDEBUG(4, "destroying /proc/video/ov511/%s/control", dirname);
		remove_proc_entry("control", ov->proc_devdir);
		ov->proc_control = NULL;
	}

	/* Destroy "button" entry */
	if (ov->proc_button) {
		PDEBUG(4, "destroying /proc/video/ov511/%s/button", dirname);
		remove_proc_entry("button", ov->proc_devdir);
		ov->proc_button = NULL;
	}

	/* Destroy "info" entry */
	if (ov->proc_info) {
		PDEBUG(4, "destroying /proc/video/ov511/%s/info", dirname);
		remove_proc_entry("info", ov->proc_devdir);
		ov->proc_info = NULL;
	}

	/* Destroy per-device directory */
	PDEBUG(4, "destroying /proc/video/ov511/%s/", dirname);
	remove_proc_entry(dirname, ov511_proc_entry);
	ov->proc_devdir = NULL;
}

static void
proc_ov511_create(void)
{
	/* No current standard here. Alan prefers /proc/video/ as it keeps
	 * /proc "less cluttered than /proc/randomcardifoundintheshed/"
	 * -claudio
	 */
	if (video_proc_entry == NULL) {
		err("Error: /proc/video/ does not exist");
		return;
	}

	ov511_proc_entry = create_proc_entry("ov511", S_IFDIR,
					     video_proc_entry);

	if (ov511_proc_entry)
		ov511_proc_entry->owner = THIS_MODULE;
	else
		err("Unable to create /proc/video/ov511");
}

static void
proc_ov511_destroy(void)
{
	PDEBUG(3, "removing /proc/video/ov511");

	if (ov511_proc_entry == NULL)
		return;

	remove_proc_entry("ov511", video_proc_entry);
}
#endif /* CONFIG_PROC_FS && CONFIG_VIDEO_PROC_FS */

/**********************************************************************
 *
 * Register I/O
 *
 **********************************************************************/

/* Write an OV51x register */
static int
reg_w(struct usb_ov511 *ov, unsigned char reg, unsigned char value)
{
	int rc;

	PDEBUG(5, "0x%02X:0x%02X", reg, value);

	down(&ov->cbuf_lock);
	ov->cbuf[0] = value;
	rc = usb_control_msg(ov->dev,
			     usb_sndctrlpipe(ov->dev, 0),
			     (ov->bclass == BCL_OV518)?1:2 /* REG_IO */,
			     USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			     0, (__u16)reg, &ov->cbuf[0], 1, HZ);
	up(&ov->cbuf_lock);

	if (rc < 0)
		err("reg write: error %d: %s", rc, symbolic(urb_errlist, rc));

	return rc;
}

/* Read from an OV51x register */
/* returns: negative is error, pos or zero is data */
static int
reg_r(struct usb_ov511 *ov, unsigned char reg)
{
	int rc;

	down(&ov->cbuf_lock);
	rc = usb_control_msg(ov->dev,
			     usb_rcvctrlpipe(ov->dev, 0),
			     (ov->bclass == BCL_OV518)?1:3 /* REG_IO */,
			     USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			     0, (__u16)reg, &ov->cbuf[0], 1, HZ);

	if (rc < 0) {
		err("reg read: error %d: %s", rc, symbolic(urb_errlist, rc));
	} else {
		rc = ov->cbuf[0];
		PDEBUG(5, "0x%02X:0x%02X", reg, ov->cbuf[0]);
	}

	up(&ov->cbuf_lock);

	return rc;
}

/*
 * Writes bits at positions specified by mask to an OV51x reg. Bits that are in
 * the same position as 1's in "mask" are cleared and set to "value". Bits
 * that are in the same position as 0's in "mask" are preserved, regardless
 * of their respective state in "value".
 */
static int
reg_w_mask(struct usb_ov511 *ov,
	   unsigned char reg,
	   unsigned char value,
	   unsigned char mask)
{
	int ret;
	unsigned char oldval, newval;

	ret = reg_r(ov, reg);
	if (ret < 0)
		return ret;

	oldval = (unsigned char) ret;
	oldval &= (~mask);		/* Clear the masked bits */
	value &= mask;			/* Enforce mask on value */
	newval = oldval | value;	/* Set the desired bits */

	return (reg_w(ov, reg, newval));
}

/* 
 * Writes multiple (n) byte value to a single register. Only valid with certain
 * registers (0x30 and 0xc4 - 0xce).
 */
static int
ov518_reg_w32(struct usb_ov511 *ov, unsigned char reg, u32 val, int n)
{
	int rc;

	PDEBUG(5, "0x%02X:%7d, n=%d", reg, val, n);

	down(&ov->cbuf_lock);

	*((u32 *)ov->cbuf) = __cpu_to_le32(val);

	rc = usb_control_msg(ov->dev,
			     usb_sndctrlpipe(ov->dev, 0),
			     1 /* REG_IO */,
			     USB_TYPE_VENDOR | USB_RECIP_DEVICE,
			     0, (__u16)reg, ov->cbuf, n, HZ);
	up(&ov->cbuf_lock);

	if (rc < 0)
		err("reg write multiple: error %d: %s", rc,
		    symbolic(urb_errlist, rc));

	return rc;
}

static int
ov511_upload_quan_tables(struct usb_ov511 *ov)
{
	unsigned char *pYTable = yQuanTable511;
	unsigned char *pUVTable = uvQuanTable511;
	unsigned char val0, val1;
	int i, rc, reg = R511_COMP_LUT_BEGIN;

	PDEBUG(4, "Uploading quantization tables");

	for (i = 0; i < OV511_QUANTABLESIZE / 2; i++) {
		if (ENABLE_Y_QUANTABLE)	{
			val0 = *pYTable++;
			val1 = *pYTable++;
			val0 &= 0x0f;
			val1 &= 0x0f;
			val0 |= val1 << 4;
			rc = reg_w(ov, reg, val0);
			if (rc < 0)
				return rc;
		}

		if (ENABLE_UV_QUANTABLE) {
			val0 = *pUVTable++;
			val1 = *pUVTable++;
			val0 &= 0x0f;
			val1 &= 0x0f;
			val0 |= val1 << 4;
			rc = reg_w(ov, reg + OV511_QUANTABLESIZE/2, val0);
			if (rc < 0)
				return rc;
		}

		reg++;
	}

	return 0;
}

/* OV518 quantization tables are 8x4 (instead of 8x8) */
static int
ov518_upload_quan_tables(struct usb_ov511 *ov)
{
	unsigned char *pYTable = yQuanTable518;
	unsigned char *pUVTable = uvQuanTable518;
	unsigned char val0, val1;
	int i, rc, reg = R511_COMP_LUT_BEGIN;

	PDEBUG(4, "Uploading quantization tables");

	for (i = 0; i < OV518_QUANTABLESIZE / 2; i++) {
		if (ENABLE_Y_QUANTABLE) {
			val0 = *pYTable++;
			val1 = *pYTable++;
			val0 &= 0x0f;
			val1 &= 0x0f;
			val0 |= val1 << 4;
			rc = reg_w(ov, reg, val0);
			if (rc < 0)
				return rc;
		}

		if (ENABLE_UV_QUANTABLE) {
			val0 = *pUVTable++;
			val1 = *pUVTable++;
			val0 &= 0x0f;
			val1 &= 0x0f;
			val0 |= val1 << 4;
			rc = reg_w(ov, reg + OV518_QUANTABLESIZE/2, val0);
			if (rc < 0)
				return rc;
		}

		reg++;
	}

	return 0;
}

static int
ov51x_reset(struct usb_ov511 *ov, unsigned char reset_type)
{
	int rc;

	/* Setting bit 0 not allowed on 518/518Plus */
	if (ov->bclass == BCL_OV518)
		reset_type &= 0xfe;

	PDEBUG(4, "Reset: type=0x%02X", reset_type);

	rc = reg_w(ov, R51x_SYS_RESET, reset_type);
	rc = reg_w(ov, R51x_SYS_RESET, 0);

	if (rc < 0)
		err("reset: command failed");

	return rc;
}

/**********************************************************************
 *
 * Low-level I2C I/O functions
 *
 **********************************************************************/

/* NOTE: Do not call this function directly!
 * The OV518 I2C I/O procedure is different, hence, this function.
 * This is normally only called from i2c_w(). Note that this function
 * always succeeds regardless of whether the sensor is present and working.
 */
static int
ov518_i2c_write_internal(struct usb_ov511 *ov,
			 unsigned char reg,
			 unsigned char value)
{
	int rc;

	PDEBUG(5, "0x%02X:0x%02X", reg, value);

	/* Select camera register */
	rc = reg_w(ov, R51x_I2C_SADDR_3, reg);
	if (rc < 0) return rc;

	/* Write "value" to I2C data port of OV511 */
	rc = reg_w(ov, R51x_I2C_DATA, value);
	if (rc < 0) return rc;

	/* Initiate 3-byte write cycle */
	rc = reg_w(ov, R518_I2C_CTL, 0x01);
	if (rc < 0) return rc;

	return 0;
}

/* NOTE: Do not call this function directly! */
static int
ov511_i2c_write_internal(struct usb_ov511 *ov,
			 unsigned char reg,
			 unsigned char value)
{
	int rc, retries;

	PDEBUG(5, "0x%02X:0x%02X", reg, value);

	/* Three byte write cycle */
	for (retries = OV511_I2C_RETRIES; ; ) {
		/* Select camera register */
		rc = reg_w(ov, R51x_I2C_SADDR_3, reg);
		if (rc < 0) return rc;

		/* Write "value" to I2C data port of OV511 */
		rc = reg_w(ov, R51x_I2C_DATA, value);
		if (rc < 0) return rc;

		/* Initiate 3-byte write cycle */
		rc = reg_w(ov, R511_I2C_CTL, 0x01);
		if (rc < 0) return rc;

		do rc = reg_r(ov, R511_I2C_CTL);
		while (rc > 0 && ((rc&1) == 0)); /* Retry until idle */
		if (rc < 0) return rc;

		if ((rc&2) == 0) /* Ack? */
			break;
#if 0
		/* I2C abort */
		reg_w(ov, R511_I2C_CTL, 0x10);
#endif
		if (--retries < 0) {
			err("i2c write retries exhausted");
			return -1;
		}
	}

	return 0;
}

/* NOTE: Do not call this function directly!
 * The OV518 I2C I/O procedure is different, hence, this function.
 * This is normally only called from i2c_r(). Note that this function
 * always succeeds regardless of whether the sensor is present and working.
 */
static int
ov518_i2c_read_internal(struct usb_ov511 *ov, unsigned char reg)
{
	int rc, value;

	/* Select camera register */
	rc = reg_w(ov, R51x_I2C_SADDR_2, reg);
	if (rc < 0) return rc;

	/* Initiate 2-byte write cycle */
	rc = reg_w(ov, R518_I2C_CTL, 0x03);
	if (rc < 0) return rc;

	/* Initiate 2-byte read cycle */
	rc = reg_w(ov, R518_I2C_CTL, 0x05);
	if (rc < 0) return rc;

	value = reg_r(ov, R51x_I2C_DATA);

	PDEBUG(5, "0x%02X:0x%02X", reg, value);

	return value;
}

/* NOTE: Do not call this function directly!
 * returns: negative is error, pos or zero is data */
static int
ov511_i2c_read_internal(struct usb_ov511 *ov, unsigned char reg)
{
	int rc, value, retries;

	/* Two byte write cycle */
	for (retries = OV511_I2C_RETRIES; ; ) {
		/* Select camera register */
		rc = reg_w(ov, R51x_I2C_SADDR_2, reg);
		if (rc < 0) return rc;

		/* Initiate 2-byte write cycle */
		rc = reg_w(ov, R511_I2C_CTL, 0x03);
		if (rc < 0) return rc;

		do rc = reg_r(ov, R511_I2C_CTL);
		while (rc > 0 && ((rc&1) == 0)); /* Retry until idle */
		if (rc < 0) return rc;

		if ((rc&2) == 0) /* Ack? */
			break;

		/* I2C abort */
		reg_w(ov, R511_I2C_CTL, 0x10);

		if (--retries < 0) {
			err("i2c write retries exhausted");
			return -1;
		}
	}

	/* Two byte read cycle */
	for (retries = OV511_I2C_RETRIES; ; ) {
		/* Initiate 2-byte read cycle */
		rc = reg_w(ov, R511_I2C_CTL, 0x05);
		if (rc < 0) return rc;

		do rc = reg_r(ov, R511_I2C_CTL);
		while (rc > 0 && ((rc&1) == 0)); /* Retry until idle */
		if (rc < 0) return rc;

		if ((rc&2) == 0) /* Ack? */
			break;

		/* I2C abort */
		rc = reg_w(ov, R511_I2C_CTL, 0x10);
		if (rc < 0) return rc;

		if (--retries < 0) {
			err("i2c read retries exhausted");
			return -1;
		}
	}

	value = reg_r(ov, R51x_I2C_DATA);

	PDEBUG(5, "0x%02X:0x%02X", reg, value);

	/* This is needed to make i2c_w() work */
	rc = reg_w(ov, R511_I2C_CTL, 0x05);
	if (rc < 0)
		return rc;

	return value;
}

/* returns: negative is error, pos or zero is data */
static int
i2c_r(struct usb_ov511 *ov, unsigned char reg)
{
	int rc;

	down(&ov->i2c_lock);

	if (ov->bclass == BCL_OV518)
		rc = ov518_i2c_read_internal(ov, reg);
	else
		rc = ov511_i2c_read_internal(ov, reg);

	up(&ov->i2c_lock);

	return rc;
}

static int
i2c_w(struct usb_ov511 *ov, unsigned char reg, unsigned char value)
{
	int rc;

	down(&ov->i2c_lock);

	if (ov->bclass == BCL_OV518)
		rc = ov518_i2c_write_internal(ov, reg, value);
	else
		rc = ov511_i2c_write_internal(ov, reg, value);

	up(&ov->i2c_lock);

	return rc;