/* Return -1 on error. */
static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data * data)
{
switch (size) {
case I2C_SMBUS_QUICK:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
size = SIS96x_QUICK;
break;
case I2C_SMBUS_BYTE:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
if (read_write == I2C_SMBUS_WRITE)
sis96x_write(SMB_CMD, command);
size = SIS96x_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
sis96x_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE)
sis96x_write(SMB_BYTE, data->byte);
size = SIS96x_BYTE_DATA;
break;
case I2C_SMBUS_PROC_CALL:
case I2C_SMBUS_WORD_DATA:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
sis96x_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE) {
sis96x_write(SMB_BYTE, data->word & 0xff);
sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
}
size = (size == I2C_SMBUS_PROC_CALL ?
SIS96x_PROC_CALL : SIS96x_WORD_DATA);
break;
case I2C_SMBUS_BLOCK_DATA:
/* TO DO: */
dev_info(&adap->dev, "SMBus block not implemented!\n");
return -1;
break;
default:
dev_info(&adap->dev, "Unsupported I2C size\n");
return -1;
break;
}
static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data * data)
{
int status;
switch (size) {
case I2C_SMBUS_QUICK:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
size = SIS96x_QUICK;
break;
case I2C_SMBUS_BYTE:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
if (read_write == I2C_SMBUS_WRITE)
sis96x_write(SMB_CMD, command);
size = SIS96x_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
sis96x_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE)
sis96x_write(SMB_BYTE, data->byte);
size = SIS96x_BYTE_DATA;
break;
case I2C_SMBUS_PROC_CALL:
case I2C_SMBUS_WORD_DATA:
sis96x_write(SMB_ADDR, ((addr & 0x7f) << 1) | (read_write & 0x01));
sis96x_write(SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE) {
sis96x_write(SMB_BYTE, data->word & 0xff);
sis96x_write(SMB_BYTE + 1, (data->word & 0xff00) >> 8);
}
size = (size == I2C_SMBUS_PROC_CALL ?
SIS96x_PROC_CALL : SIS96x_WORD_DATA);
break;
default:
dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
return -EOPNOTSUPP;
}
static int sis96x_transaction(int size)
{
int temp;
int result = 0;
int timeout = 0;
dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size);
if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). "
"Resetting...\n", temp);
sis96x_write(SMB_HOST_CNT, 0x20);
if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);
return -EBUSY;
} else {
dev_dbg(&sis96x_adapter.dev, "Successful\n");
}
}
sis96x_write(SMB_CNT, 0x20);
temp = sis96x_read(SMB_STS);
sis96x_write(SMB_STS, temp & 0x1e);
sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07));
do {
msleep(1);
temp = sis96x_read(SMB_STS);
} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
if (timeout > MAX_TIMEOUT) {
dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);
result = -ETIMEDOUT;
}
if (temp & 0x02) {
dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");
result = -ENXIO;
}
if (temp & 0x04) {
dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");
result = -EIO;
}
sis96x_write(SMB_STS, temp);
if ((temp = sis96x_read(SMB_STS))) {
dev_dbg(&sis96x_adapter.dev, "Failed reset at "
"end of transaction! (0x%02x)\n", temp);
}
return result;
}
/* Execute a SMBus transaction.
int size is from SIS96x_QUICK to SIS96x_BLOCK_DATA
*/
static int sis96x_transaction(int size)
{
int temp;
int result = 0;
int timeout = 0;
dev_dbg(&sis96x_adapter.dev, "SMBus transaction %d\n", size);
/* Make sure the SMBus host is ready to start transmitting */
if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
dev_dbg(&sis96x_adapter.dev, "SMBus busy (0x%02x). "
"Resetting...\n", temp);
/* kill the transaction */
sis96x_write(SMB_HOST_CNT, 0x20);
/* check it again */
if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);
return -EBUSY;
} else {
dev_dbg(&sis96x_adapter.dev, "Successful\n");
}
}
/* Turn off timeout interrupts, set fast host clock */
sis96x_write(SMB_CNT, 0x20);
/* clear all (sticky) status flags */
temp = sis96x_read(SMB_STS);
sis96x_write(SMB_STS, temp & 0x1e);
/* start the transaction by setting bit 4 and size bits */
sis96x_write(SMB_HOST_CNT, 0x10 | (size & 0x07));
/* We will always wait for a fraction of a second! */
do {
msleep(1);
temp = sis96x_read(SMB_STS);
} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
/* If the SMBus is still busy, we give up */
if (timeout > MAX_TIMEOUT) {
dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);
result = -ETIMEDOUT;
}
/* device error - probably missing ACK */
if (temp & 0x02) {
dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");
result = -ENXIO;
}
/* bus collision */
if (temp & 0x04) {
dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");
result = -EIO;
}
/* Finish up by resetting the bus */
sis96x_write(SMB_STS, temp);
if ((temp = sis96x_read(SMB_STS))) {
dev_dbg(&sis96x_adapter.dev, "Failed reset at "
"end of transaction! (0x%02x)\n", temp);
}
return result;
}
