ov511.c

linux下的usb接口驱动程序

	int rc, value;

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

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

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

	value = reg_r(ov, R51x_I2C_DATA);

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

	return value;

error:
	err("ov518 i2c read: error %d", rc);
	return rc;
}

/* 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) goto error;

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

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

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

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

		if (--retries < 0) {
			err("i2c write retries exhausted");
			rc = -1;
			goto error;
		}
	}

	/* 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) goto error;

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

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

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

		if (--retries < 0) {
			err("i2c read retries exhausted");
			rc = -1;
			goto error;
		}
	}

	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)
		goto error;
	
	return value;

error:
	err("i2c read: error %d", rc);
	return rc;
}

/* 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;
}

/* Do not call this function directly! */
static int 
ov51x_i2c_write_mask_internal(struct usb_ov511 *ov,
			      unsigned char reg,
			      unsigned char value,
			      unsigned char mask)
{
	int rc;
	unsigned char oldval, newval;

	if (mask == 0xff) {
		newval = value;
	} else {
		if (ov->bclass == BCL_OV518)
			rc = ov518_i2c_read_internal(ov, reg);
		else
			rc = ov511_i2c_read_internal(ov, reg);
		if (rc < 0)
			return rc;

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

	if (ov->bclass == BCL_OV518)
		return (ov518_i2c_write_internal(ov, reg, newval));
	else
		return (ov511_i2c_write_internal(ov, reg, newval));
}

/* Writes bits at positions specified by mask to an I2C 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 
i2c_w_mask(struct usb_ov511 *ov,
	   unsigned char reg,
	   unsigned char value,
	   unsigned char mask)
{
	int rc;

	down(&ov->i2c_lock);
	rc = ov51x_i2c_write_mask_internal(ov, reg, value, mask);
	up(&ov->i2c_lock);

	return rc;
}

/* Write to a specific I2C slave ID and register, using the specified mask */
static int 
i2c_w_slave(struct usb_ov511 *ov,
	    unsigned char slave,
	    unsigned char reg,
	    unsigned char value,
	    unsigned char mask)
{
	int rc = 0;

	down(&ov->i2c_lock);

	/* Set new slave IDs */
	if (reg_w(ov, R51x_I2C_W_SID, slave) < 0) {
		rc = -EIO;
		goto out;
	}

	if (reg_w(ov, R51x_I2C_R_SID, slave + 1) < 0) {
		rc = -EIO;
		goto out;
	}

	rc = ov51x_i2c_write_mask_internal(ov, reg, value, mask);
	/* Don't bail out yet if error; IDs must be restored */

	/* Restore primary IDs */
	slave = ov->primary_i2c_slave;
	if (reg_w(ov, R51x_I2C_W_SID, slave) < 0) {
		rc = -EIO;
		goto out;
	}

	if (reg_w(ov, R51x_I2C_R_SID, slave + 1) < 0) {
		rc = -EIO;
		goto out;
	}

out:
	up(&ov->i2c_lock);
	return rc;
}

/* Read from a specific I2C slave ID and register */
static int 
i2c_r_slave(struct usb_ov511 *ov,
	    unsigned char slave,
	    unsigned char reg)
{
	int rc;

	down(&ov->i2c_lock);

	/* Set new slave IDs */
	if (reg_w(ov, R51x_I2C_W_SID, slave) < 0) {
		rc = -EIO;
		goto out;
	}

	if (reg_w(ov, R51x_I2C_R_SID, slave + 1) < 0) {
		rc = -EIO;
		goto out;
	}

	if (ov->bclass == BCL_OV518)
		rc = ov518_i2c_read_internal(ov, reg);
	else
		rc = ov511_i2c_read_internal(ov, reg);
	/* Don't bail out yet if error; IDs must be restored */

	/* Restore primary IDs */
	slave = ov->primary_i2c_slave;
	if (reg_w(ov, R51x_I2C_W_SID, slave) < 0) {
		rc = -EIO;
		goto out;
	}

	if (reg_w(ov, R51x_I2C_R_SID, slave + 1) < 0) {
		rc = -EIO;
		goto out;
	}

out:
	up(&ov->i2c_lock);
	return rc;
}

/* Sets I2C read and write slave IDs. Returns <0 for error */
static int 
ov51x_set_slave_ids(struct usb_ov511 *ov, unsigned char sid)
{
	down(&ov->i2c_lock);

	if (reg_w(ov, R51x_I2C_W_SID, sid) < 0)
		return -EIO;

	if (reg_w(ov, R51x_I2C_R_SID, sid + 1) < 0)
		return -EIO;

	if (ov51x_reset(ov, OV511_RESET_NOREGS) < 0)
		return -EIO;

	up(&ov->i2c_lock);

	return 0;
}

static int 
write_regvals(struct usb_ov511 *ov, struct ov511_regvals * pRegvals)
{
	int rc;

	while (pRegvals->bus != OV511_DONE_BUS) {
		if (pRegvals->bus == OV511_REG_BUS) {
			if ((rc = reg_w(ov, pRegvals->reg, pRegvals->val)) < 0)
				goto error;
		} else if (pRegvals->bus == OV511_I2C_BUS) {
			if ((rc = i2c_w(ov, pRegvals->reg, pRegvals->val)) < 0)
				goto error;
		} else {
			err("Bad regval array");
			rc = -1;
			goto error;
		}
		pRegvals++;
	}
	return 0;

error:
	err("write regvals: error %d", rc);
	return rc;
}

#ifdef OV511_DEBUG 
static void 
dump_i2c_range(struct usb_ov511 *ov, int reg1, int regn)
{
	int i;
	int rc;

	for (i = reg1; i <= regn; i++) {
		rc = i2c_r(ov, i);
		info("OV7610[0x%X] = 0x%X", i, rc);
	}
}

static void 
dump_i2c_regs(struct usb_ov511 *ov)
{
	info("I2C REGS");
	dump_i2c_range(ov, 0x00, 0x7C);
}

static void 
dump_reg_range(struct usb_ov511 *ov, int reg1, int regn)
{
	int i;
	int rc;

	for (i = reg1; i <= regn; i++) {
		rc = reg_r(ov, i);
		info("OV511[0x%X] = 0x%X", i, rc);
	}
}

/* FIXME: Should there be an OV518 version of this? */
static void 
ov511_dump_regs(struct usb_ov511 *ov)
{
	info("CAMERA INTERFACE REGS");
	dump_reg_range(ov, 0x10, 0x1f);
	info("DRAM INTERFACE REGS");
	dump_reg_range(ov, 0x20, 0x23);
	info("ISO FIFO REGS");
	dump_reg_range(ov, 0x30, 0x31);
	info("PIO REGS");
	dump_reg_range(ov, 0x38, 0x39);
	dump_reg_range(ov, 0x3e, 0x3e);
	info("I2C REGS");
	dump_reg_range(ov, 0x40, 0x49);
	info("SYSTEM CONTROL REGS");
	dump_reg_range(ov, 0x50, 0x55);
	dump_reg_range(ov, 0x5e, 0x5f);
	info("OmniCE REGS");
	dump_reg_range(ov, 0x70, 0x79);
	/* NOTE: Quantization tables are not readable. You will get the value
	 * in reg. 0x79 for every table register */
	dump_reg_range(ov, 0x80, 0x9f);
	dump_reg_range(ov, 0xa0, 0xbf);

}
#endif

/**********************************************************************
 *
 * Kernel I2C Interface
 *
 **********************************************************************/

/* For as-yet unimplemented I2C interface */
static void 
call_i2c_clients(struct usb_ov511 *ov, unsigned int cmd,
		 void *arg)
{
	/* Do nothing */
}

/*****************************************************************************/

/* Temporarily stops OV511 from functioning. Must do this before changing
 * registers while the camera is streaming */
static inline int 
ov51x_stop(struct usb_ov511 *ov)
{
	PDEBUG(4, "stopping");
	ov->stopped = 1;	
	if (ov->bclass == BCL_OV518)
		return (reg_w(ov, R51x_SYS_RESET, 0x3a));
	else
		return (reg_w(ov, R51x_SYS_RESET, 0x3d));
}

/* Restarts OV511 after ov511_stop() is called. Has no effect if it is not
 * actually stopped (for performance). */
static inline int 
ov51x_restart(struct usb_ov511 *ov)
{
	if (ov->stopped) {
		PDEBUG(4, "restarting");
		ov->stopped = 0;	

		/* Reinitialize the stream */
		if (ov->bclass == BCL_OV518)
			reg_w(ov, 0x2f, 0x80);

		return (reg_w(ov, R51x_SYS_RESET, 0x00));
	}

	return 0;
}

/* Resets the hardware snapshot button */
static void 
ov51x_clear_snapshot(struct usb_ov511 *ov)
{
	if (ov->bclass == BCL_OV511) {
		reg_w(ov, R51x_SYS_SNAP, 0x01);
		reg_w(ov, R51x_SYS_SNAP, 0x03);
		reg_w(ov, R51x_SYS_SNAP, 0x01);
	} else if (ov->bclass == BCL_OV518) {
		warn("snapshot reset not supported yet on OV518(+)");
	} else {
		err("clear snap: invalid bridge type");
	}
	
}

/* Checks the status of the snapshot button. Returns 1 if it was pressed since
 * it was last cleared, and zero in all other cases (including errors) */
static int 
ov51x_check_snapshot(struct usb_ov511 *ov)
{
	int ret, status = 0;

	if (ov->bclass == BCL_OV511) {
		ret = reg_r(ov, R51x_SYS_SNAP);
		if (ret < 0) {
			err("Error checking snspshot status (%d)", ret);
		} else if (ret & 0x08) {
			status = 1;
		}
	} else if (ov->bclass == BCL_OV518) {
		warn("snapshot check not supported yet on OV518(+)");
	} else {
		err("check snap: invalid bridge type");
	}

	return status;
}

/* This does an initial reset of an OmniVision sensor and ensures that I2C
 * is synchronized. Returns <0 for failure.
 */
static int 
init_ov_sensor(struct usb_ov511 *ov)
{
	int i, success;

	/* Reset the sensor */ 
	if (i2c_w(ov, 0x12, 0x80) < 0) return -EIO;

	/* Wait for it to initialize */ 
	schedule_timeout (1 + 150 * HZ / 1000);

	for (i = 0, success = 0; i < i2c_detect_tries && !success; i++) {
		if ((i2c_r(ov, OV7610_REG_ID_HIGH) == 0x7F) &&
		    (i2c_r(ov, OV7610_REG_ID_LOW) == 0xA2)) {
			success = 1;
			continue;
		}

		/* Reset the sensor */ 
		if (i2c_w(ov, 0x12, 0x80) < 0) return -EIO;
		/* Wait for it to initialize */ 
		schedule_timeout(1 + 150 * HZ / 1000);
		/* Dummy read to sync I2C */
		if (i2c_r(ov, 0x00) < 0) return -EIO;
	}

	if (!success)
		return -EIO;
	
	PDEBUG(1, "I2C synced in %d attempt(s)", i);

	return 0;
}

static int 
ov51x_set_packet_size(struct usb_ov511 *ov, int size)
{
	int alt, mult;

	if (ov51x_stop(ov) < 0)
		return -EIO;

	mult = size >> 5;

	if (ov->bridge == BRG_OV511) {
		if (size == 0) alt = OV511_ALT_SIZE_0;
		else if (size == 257) alt = OV511_ALT_SIZE_257;
		else if (size == 513) alt = OV511_ALT_SIZE_513;
		else if (size == 769) alt = OV511_ALT_SIZE_769;
		else if (size == 993) alt = OV511_ALT_SIZE_993;
		else {
			err("Set packet size: invalid size (%d)", size);
			return -EINVAL;
		}
	} else if (ov->bridge == BRG_OV511PLUS) {
		if (size == 0) alt = OV511PLUS_ALT_SIZE_0;
		else if (size == 33) alt = OV511PLUS_ALT_SIZE_33;
		else if (size == 129) alt = OV511PLUS_ALT_SIZE_129;
		else if (size == 257) alt = OV511PLUS_ALT_SIZE_257;
		else if (size == 385) alt = OV511PLUS_ALT_SIZE_385;
		else if (size == 513) alt = OV511PLUS_ALT_SIZE_513;
		else if (size == 769) alt = OV511PLUS_ALT_SIZE_769;
		else if (size == 961) alt = OV511PLUS_ALT_SIZE_961;
		else {
			err("Set packet size: invalid size (%d)", size);