w9968cf.c

V4l driver for DVB HD

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 int
w9968cf_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 int
w9968cf_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 int
w9968cf_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 int
w9968cf_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 int
w9968cf_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 int
w9968cf_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;
}



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