static int w9968cf_smbus_stop(struct w9968cf_device* cam){	int err = 0;	err += w9968cf_write_sb(cam, 0x0011); /* SDE=1, SDA=0, SCL=1 */	err += w9968cf_write_sb(cam, 0x0013); /* SDE=1, SDA=1, SCL=1 */	return err;}static int w9968cf_smbus_write_byte(struct w9968cf_device* cam, u8 v){	u8 bit;	int err = 0, sda;	for (bit = 0 ; bit < 8 ; bit++) {		sda = (v & 0x80) ? 2 : 0;		v <<= 1;		/* SDE=1, SDA=sda, SCL=0 */		err += w9968cf_write_sb(cam, 0x10 | sda);		/* SDE=1, SDA=sda, SCL=1 */		err += w9968cf_write_sb(cam, 0x11 | sda);		/* SDE=1, SDA=sda, SCL=0 */		err += w9968cf_write_sb(cam, 0x10 | sda);	}	return err;}static int w9968cf_smbus_read_byte(struct w9968cf_device* cam, u8* v){	u8 bit;	int err = 0;	*v = 0;	for (bit = 0 ; bit < 8 ; bit++) {		*v <<= 1;		err += w9968cf_write_sb(cam, 0x0013);		*v |= (w9968cf_read_sb(cam) & 0x0008) ? 1 : 0;		err += w9968cf_write_sb(cam, 0x0012);	}	return err;}static int w9968cf_smbus_write_ack(struct w9968cf_device* cam){	int err = 0;	err += w9968cf_write_sb(cam, 0x0010); /* SDE=1, SDA=0, SCL=0 */	err += w9968cf_write_sb(cam, 0x0011); /* SDE=1, SDA=0, SCL=1 */	err += w9968cf_write_sb(cam, 0x0010); /* SDE=1, SDA=0, SCL=0 */	return err;}static int w9968cf_smbus_read_ack(struct w9968cf_device* cam){	int err = 0, sda;	err += w9968cf_write_sb(cam, 0x0013); /* SDE=1, SDA=1, SCL=1 */	sda = (w9968cf_read_sb(cam) & 0x08) ? 1 : 0; /* sda = SDA */	err += w9968cf_write_sb(cam, 0x0012); /* SDE=1, SDA=1, SCL=0 */	if (sda < 0)		err += sda;	if (sda == 1) {		DBG(6, "Couldn't receive the ACK")		err += -1;	}	return err;}/* This seems to refresh the communication through the serial bus */static int w9968cf_smbus_refresh_bus(struct w9968cf_device* cam){	int err = 0, j;	for (j = 1; j <= 10; j++) {		err = w9968cf_write_reg(cam, 0x0020, 0x01);		err += w9968cf_write_reg(cam, 0x0000, 0x01);		if (err)			break;	}	return err;}/* SMBus protocol: S Addr Wr [A] Subaddr [A] Value [A] P */static intw9968cf_i2c_adap_fastwrite_byte_data(struct w9968cf_device* cam,				     u16 address, u8 subaddress,u8 value){	u16* data = cam->data_buffer;	int err = 0;	err += w9968cf_smbus_refresh_bus(cam);	/* Enable SBUS outputs */	err += w9968cf_write_sb(cam, 0x0020);	data[0] = 0x082f | ((address & 0x80) ? 0x1500 : 0x0);	data[0] |= (address & 0x40) ? 0x4000 : 0x0;	data[1] = 0x2082 | ((address & 0x40) ? 0x0005 : 0x0);	data[1] |= (address & 0x20) ? 0x0150 : 0x0;	data[1] |= (address & 0x10) ? 0x5400 : 0x0;	data[2] = 0x8208 | ((address & 0x08) ? 0x0015 : 0x0);	data[2] |= (address & 0x04) ? 0x0540 : 0x0;	data[2] |= (address & 0x02) ? 0x5000 : 0x0;	data[3] = 0x1d20 | ((address & 0x02) ? 0x0001 : 0x0);	data[3] |= (address & 0x01) ? 0x0054 : 0x0;	err += w9968cf_write_fsb(cam, data);	data[0] = 0x8208 | ((subaddress & 0x80) ? 0x0015 : 0x0);	data[0] |= (subaddress & 0x40) ? 0x0540 : 0x0;	data[0] |= (subaddress & 0x20) ? 0x5000 : 0x0;	data[1] = 0x0820 | ((subaddress & 0x20) ? 0x0001 : 0x0);	data[1] |= (subaddress & 0x10) ? 0x0054 : 0x0;	data[1] |= (subaddress & 0x08) ? 0x1500 : 0x0;	data[1] |= (subaddress & 0x04) ? 0x4000 : 0x0;	data[2] = 0x2082 | ((subaddress & 0x04) ? 0x0005 : 0x0);	data[2] |= (subaddress & 0x02) ? 0x0150 : 0x0;	data[2] |= (subaddress & 0x01) ? 0x5400 : 0x0;	data[3] = 0x001d;	err += w9968cf_write_fsb(cam, data);	data[0] = 0x8208 | ((value & 0x80) ? 0x0015 : 0x0);	data[0] |= (value & 0x40) ? 0x0540 : 0x0;	data[0] |= (value & 0x20) ? 0x5000 : 0x0;	data[1] = 0x0820 | ((value & 0x20) ? 0x0001 : 0x0);	data[1] |= (value & 0x10) ? 0x0054 : 0x0;	data[1] |= (value & 0x08) ? 0x1500 : 0x0;	data[1] |= (value & 0x04) ? 0x4000 : 0x0;	data[2] = 0x2082 | ((value & 0x04) ? 0x0005 : 0x0);	data[2] |= (value & 0x02) ? 0x0150 : 0x0;	data[2] |= (value & 0x01) ? 0x5400 : 0x0;	data[3] = 0xfe1d;	err += w9968cf_write_fsb(cam, data);	/* Disable SBUS outputs */	err += w9968cf_write_sb(cam, 0x0000);	if (!err)		DBG(5, "I2C write byte data done, addr.0x%04X, subaddr.0x%02X "		       "value 0x%02X", address, subaddress, value)	else		DBG(5, "I2C write byte data failed, addr.0x%04X, "		       "subaddr.0x%02X, value 0x%02X",		    address, subaddress, value)	return err;}/* SMBus protocol: S Addr Wr [A] Subaddr [A] P S Addr+1 Rd [A] [Value] NA P */static intw9968cf_i2c_adap_read_byte_data(struct w9968cf_device* cam,				u16 address, u8 subaddress,				u8* value){	int err = 0;	/* Serial data enable */	err += w9968cf_write_sb(cam, 0x0013); /* don't change ! */	err += w9968cf_smbus_start(cam);	err += w9968cf_smbus_write_byte(cam, address);	err += w9968cf_smbus_read_ack(cam);	err += w9968cf_smbus_write_byte(cam, subaddress);	err += w9968cf_smbus_read_ack(cam);	err += w9968cf_smbus_stop(cam);	err += w9968cf_smbus_start(cam);	err += w9968cf_smbus_write_byte(cam, address + 1);	err += w9968cf_smbus_read_ack(cam);	err += w9968cf_smbus_read_byte(cam, value);	err += w9968cf_smbus_write_ack(cam);	err += w9968cf_smbus_stop(cam);	/* Serial data disable */	err += w9968cf_write_sb(cam, 0x0000);	if (!err)		DBG(5, "I2C read byte data done, addr.0x%04X, "		       "subaddr.0x%02X, value 0x%02X",		    address, subaddress, *value)	else		DBG(5, "I2C read byte data failed, addr.0x%04X, "		       "subaddr.0x%02X, wrong value 0x%02X",		    address, subaddress, *value)	return err;}/* SMBus protocol: S Addr+1 Rd [A] [Value] NA P */static intw9968cf_i2c_adap_read_byte(struct w9968cf_device* cam,			   u16 address, u8* value){	int err = 0;	/* Serial data enable */	err += w9968cf_write_sb(cam, 0x0013);	err += w9968cf_smbus_start(cam);	err += w9968cf_smbus_write_byte(cam, address + 1);	err += w9968cf_smbus_read_ack(cam);	err += w9968cf_smbus_read_byte(cam, value);	err += w9968cf_smbus_write_ack(cam);	err += w9968cf_smbus_stop(cam);	/* Serial data disable */	err += w9968cf_write_sb(cam, 0x0000);	if (!err)		DBG(5, "I2C read byte done, addr.0x%04X, "		       "value 0x%02X", address, *value)	else		DBG(5, "I2C read byte failed, addr.0x%04X, "		       "wrong value 0x%02X", address, *value)	return err;}/* SMBus protocol: S Addr Wr [A] Value [A] P */static intw9968cf_i2c_adap_write_byte(struct w9968cf_device* cam,			    u16 address, u8 value){	DBG(4, "i2c_write_byte() is an unsupported transfer mode")	return -EINVAL;}/**************************************************************************** * I2C interface to kernel                                                  * ****************************************************************************/static intw9968cf_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,		       unsigned short flags, char read_write, u8 command,		       int size, union i2c_smbus_data *data){	struct w9968cf_device* cam = i2c_get_adapdata(adapter);	u8 i;	int err = 0;	switch (addr) {		case OV6xx0_SID:		case OV7xx0_SID:			break;		default:			DBG(4, "Rejected slave ID 0x%04X", addr)			return -EINVAL;	}	if (size == I2C_SMBUS_BYTE) {		/* Why addr <<= 1? See OVXXX0_SID defines in ovcamchip.h */		addr <<= 1;		if (read_write == I2C_SMBUS_WRITE)			err = w9968cf_i2c_adap_write_byte(cam, addr, command);		else if (read_write == I2C_SMBUS_READ)			err = w9968cf_i2c_adap_read_byte(cam,addr,&data->byte);	} else if (size == I2C_SMBUS_BYTE_DATA) {		addr <<= 1;		if (read_write == I2C_SMBUS_WRITE)			err = w9968cf_i2c_adap_fastwrite_byte_data(cam, addr,							  command, data->byte);		else if (read_write == I2C_SMBUS_READ) {			for (i = 1; i <= W9968CF_I2C_RW_RETRIES; i++) {				err = w9968cf_i2c_adap_read_byte_data(cam,addr,							 command, &data->byte);				if (err) {					if (w9968cf_smbus_refresh_bus(cam)) {						err = -EIO;						break;					}				} else					break;			}		} else			return -EINVAL;	} else {		DBG(4, "Unsupported I2C transfer mode (%d)", size)		return -EINVAL;	}	return err;}static u32 w9968cf_i2c_func(struct i2c_adapter* adap){	return I2C_FUNC_SMBUS_READ_BYTE |	       I2C_FUNC_SMBUS_READ_BYTE_DATA  |	       I2C_FUNC_SMBUS_WRITE_BYTE_DATA;}static int w9968cf_i2c_attach_inform(struct i2c_client* client){	struct w9968cf_device* cam = i2c_get_adapdata(client->adapter);	int id = client->driver->id, err = 0;	if (id == I2C_DRIVERID_OVCAMCHIP) {		cam->sensor_client = client;		err = w9968cf_sensor_init(cam);		if (err) {			cam->sensor_client = NULL;			return err;		}	} else {		DBG(4, "Rejected client [%s] with driver [%s]",		    client->name, client->driver->driver.name)		return -EINVAL;	}	DBG(5, "I2C attach client [%s] with driver [%s]",	    client->name, client->driver->driver.name)	return 0;}static int w9968cf_i2c_detach_inform(struct i2c_client* client){	struct w9968cf_device* cam = i2c_get_adapdata(client->adapter);	if (cam->sensor_client == client)		cam->sensor_client = NULL;	DBG(5, "I2C detach client [%s]", client->name)	return 0;}static intw9968cf_i2c_control(struct i2c_adapter* adapter, unsigned int cmd,		    unsigned long arg){	return 0;}static int w9968cf_i2c_init(struct w9968cf_device* cam){	int err = 0;	static struct i2c_algorithm algo = {		.smbus_xfer =    w9968cf_i2c_smbus_xfer,		.algo_control =  w9968cf_i2c_control,		.functionality = w9968cf_i2c_func,	};	static struct i2c_adapter adap = {		.id =                I2C_HW_SMBUS_W9968CF,		.class =             I2C_CLASS_CAM_DIGITAL,		.owner =             THIS_MODULE,		.client_register =   w9968cf_i2c_attach_inform,		.client_unregister = w9968cf_i2c_detach_inform,		.algo =              &algo,	};	memcpy(&cam->i2c_adapter, &adap, sizeof(struct i2c_adapter));	strcpy(cam->i2c_adapter.name, "w9968cf");	i2c_set_adapdata(&cam->i2c_adapter, cam);	DBG(6, "Registering I2C adapter with kernel...")	err = i2c_add_adapter(&cam->i2c_adapter);	if (err)		DBG(1, "Failed to register the I2C adapter")	else		DBG(5, "I2C adapter registered")	return err;}/****************************************************************************