static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
{
int temp, result = 0, timeout = 0;
/* We will always wait for a fraction of a second! */
do {
msleep(1);
temp = sis630_read(SMB_STS);
/* check if block transmitted */
if (size == SIS630_BLOCK_DATA && (temp & BYTE_DONE_STS))
break;
} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
/* If the SMBus is still busy, we give up */
if (timeout > MAX_TIMEOUT) {
dev_dbg(&adap->dev, "SMBus Timeout!\n");
result = -ETIMEDOUT;
}
if (temp & SMBERR_STS) {
dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
result = -ENXIO;
}
if (temp & SMBCOL_STS) {
dev_err(&adap->dev, "Bus collision!\n");
result = -EAGAIN;
}
return result;
}
static void sis630_transaction_end(struct i2c_adapter *adap, u8 oldclock)
{
int temp = 0;
/* clear all status "sticky" bits */
sis630_write(SMB_STS, temp);
dev_dbg(&adap->dev, "SMB_CNT before clock restore 0x%02x\n", sis630_read(SMB_CNT));
/*
* restore old Host Master Clock if high_clock is set
* and oldclock was not 56KHz
*/
if (high_clock && !(oldclock & 0x20))
sis630_write(SMB_CNT,(sis630_read(SMB_CNT) & ~0x20));
dev_dbg(&adap->dev, "SMB_CNT after clock restore 0x%02x\n", sis630_read(SMB_CNT));
}
static int sis630_transaction_start(struct i2c_adapter *adap, int size,
u8 *oldclock)
{
int temp;
/* Make sure the SMBus host is ready to start transmitting. */
temp = sis630_read(SMB_CNT);
if ((temp & (SMB_PROBE | SMB_HOSTBUSY)) != 0x00) {
dev_dbg(&adap->dev, "SMBus busy (%02x). Resetting...\n", temp);
/* kill smbus transaction */
sis630_write(SMBHOST_CNT, SMB_KILL);
temp = sis630_read(SMB_CNT);
if (temp & (SMB_PROBE | SMB_HOSTBUSY)) {
dev_dbg(&adap->dev, "Failed! (%02x)\n", temp);
return -EBUSY;
} else {
dev_dbg(&adap->dev, "Successful!\n");
}
}
/* save old clock, so we can prevent machine for hung */
*oldclock = sis630_read(SMB_CNT);
dev_dbg(&adap->dev, "saved clock 0x%02x\n", *oldclock);
/* disable timeout interrupt,
* set Host Master Clock to 56KHz if requested */
if (high_clock)
sis630_write(SMB_CNT, SMBCLK_SEL);
else
sis630_write(SMB_CNT, (*oldclock & ~MSTO_EN));
/* clear all sticky bits */
temp = sis630_read(SMB_STS);
sis630_write(SMB_STS, temp & 0x1e);
/* start the transaction by setting bit 4 and size */
sis630_write(SMBHOST_CNT, SMB_START | (size & 0x07));
return 0;
}
static int sis630_transaction_wait(struct i2c_adapter *adap, int size)
{
int temp, result = 0, timeout = 0;
/* We will always wait for a fraction of a second! */
do {
msleep(1);
temp = sis630_read(SMB_STS);
/* check if block transmitted */
if (size == SIS630_BLOCK_DATA && (temp & 0x10))
break;
} while (!(temp & 0x0e) && (timeout++ < MAX_TIMEOUT));
/* If the SMBus is still busy, we give up */
if (timeout > MAX_TIMEOUT) {
dev_dbg(&adap->dev, "SMBus Timeout!\n");
result = -ETIMEDOUT;
}
if (temp & 0x02) {
dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
result = -ENXIO;
}
if (temp & 0x04) {
dev_err(&adap->dev, "Bus collision!\n");
result = -EIO;
/*
TBD: Datasheet say:
the software should clear this bit and restart SMBUS operation.
Should we do it or user start request again?
*/
}
return result;
}
static int sis630_block_data(struct i2c_adapter *adap, union i2c_smbus_data *data, int read_write)
{
int i, len = 0, rc = 0;
u8 oldclock = 0;
if (read_write == I2C_SMBUS_WRITE) {
len = data->block[0];
if (len < 0)
len = 0;
else if (len > 32)
len = 32;
sis630_write(SMB_COUNT, len);
for (i=1; i <= len; i++) {
dev_dbg(&adap->dev, "set data 0x%02x\n", data->block[i]);
/* set data */
sis630_write(SMB_BYTE+(i-1)%8, data->block[i]);
if (i==8 || (len<8 && i==len)) {
dev_dbg(&adap->dev, "start trans len=%d i=%d\n",len ,i);
/* first transaction */
rc = sis630_transaction_start(adap,
SIS630_BLOCK_DATA, &oldclock);
if (rc)
return rc;
}
else if ((i-1)%8 == 7 || i==len) {
dev_dbg(&adap->dev, "trans_wait len=%d i=%d\n",len,i);
if (i>8) {
dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
/*
If this is not first transaction,
we must clear sticky bit.
clear SMBARY_STS
*/
sis630_write(SMB_STS,0x10);
}
rc = sis630_transaction_wait(adap,
SIS630_BLOCK_DATA);
if (rc) {
dev_dbg(&adap->dev, "trans_wait failed\n");
break;
}
}
}
}
else {
/* read request */
data->block[0] = len = 0;
rc = sis630_transaction_start(adap,
SIS630_BLOCK_DATA, &oldclock);
if (rc)
return rc;
do {
rc = sis630_transaction_wait(adap, SIS630_BLOCK_DATA);
if (rc) {
dev_dbg(&adap->dev, "trans_wait failed\n");
break;
}
/* if this first transaction then read byte count */
if (len == 0)
data->block[0] = sis630_read(SMB_COUNT);
/* just to be sure */
if (data->block[0] > 32)
data->block[0] = 32;
dev_dbg(&adap->dev, "block data read len=0x%x\n", data->block[0]);
for (i=0; i < 8 && len < data->block[0]; i++,len++) {
dev_dbg(&adap->dev, "read i=%d len=%d\n", i, len);
data->block[len+1] = sis630_read(SMB_BYTE+i);
}
dev_dbg(&adap->dev, "clear smbary_sts len=%d i=%d\n",len,i);
/* clear SMBARY_STS */
sis630_write(SMB_STS,0x10);
} while(len < data->block[0]);
}
sis630_transaction_end(adap, oldclock);
return rc;
}
