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i2c-eg20t: Separate error processing
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Error processing for NACK or wait-event must be precessed separately.
So divide wait-event error processing into NACK-receiving and timeout.
Add arbitration lost processing.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.lapis-semi.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
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Tomoya MORINAGA authored and Ben Dooks committed Oct 29, 2011
1 parent c249ac2 commit 12bd314
Showing 1 changed file with 115 additions and 58 deletions.
173 changes: 115 additions & 58 deletions drivers/i2c/busses/i2c-eg20t.c
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Original file line number Diff line number Diff line change
Expand Up @@ -391,6 +391,7 @@ static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
u32 addr_2_msb;
u32 addr_8_lsb;
s32 wrcount;
s32 rtn;
void __iomem *p = adap->pch_base_address;

length = msgs->len;
Expand All @@ -413,11 +414,25 @@ static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
iowrite32(addr_2_msb | TEN_BIT_ADDR_MASK, p + PCH_I2CDR);
if (first)
pch_i2c_start(adap);
if (pch_i2c_wait_for_xfer_complete(adap) == 0 &&
pch_i2c_getack(adap) == 0) {

rtn = pch_i2c_wait_for_xfer_complete(adap);
if (rtn == 0) {
if (pch_i2c_getack(adap)) {
pch_dbg(adap, "Receive NACK for slave address"
"setting\n");
return -EIO;
}
addr_8_lsb = (addr & I2C_ADDR_MSK);
iowrite32(addr_8_lsb, p + PCH_I2CDR);
} else {
} else if (rtn == -EIO) { /* Arbitration Lost */
pch_err(adap, "Lost Arbitration\n");
pch_clrbit(adap->pch_base_address, PCH_I2CSR,
I2CMAL_BIT);
pch_clrbit(adap->pch_base_address, PCH_I2CSR,
I2CMIF_BIT);
pch_i2c_init(adap);
return -EAGAIN;
} else { /* wait-event timeout */
pch_i2c_stop(adap);
return -ETIME;
}
Expand All @@ -428,30 +443,48 @@ static s32 pch_i2c_writebytes(struct i2c_adapter *i2c_adap,
pch_i2c_start(adap);
}

if ((pch_i2c_wait_for_xfer_complete(adap) == 0) &&
(pch_i2c_getack(adap) == 0)) {
for (wrcount = 0; wrcount < length; ++wrcount) {
/* write buffer value to I2C data register */
iowrite32(buf[wrcount], p + PCH_I2CDR);
pch_dbg(adap, "writing %x to Data register\n",
buf[wrcount]);
rtn = pch_i2c_wait_for_xfer_complete(adap);
if (rtn == 0) {
if (pch_i2c_getack(adap)) {
pch_dbg(adap, "Receive NACK for slave address"
"setting\n");
return -EIO;
}
} else if (rtn == -EIO) { /* Arbitration Lost */
pch_err(adap, "Lost Arbitration\n");
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
return -EAGAIN;
} else { /* wait-event timeout */
return -ETIME;
}

if (pch_i2c_wait_for_xfer_complete(adap) != 0)
return -ETIME;
for (wrcount = 0; wrcount < length; ++wrcount) {
/* write buffer value to I2C data register */
iowrite32(buf[wrcount], p + PCH_I2CDR);
pch_dbg(adap, "writing %x to Data register\n", buf[wrcount]);

if (pch_i2c_getack(adap))
rtn = pch_i2c_wait_for_xfer_complete(adap);
if (rtn == 0) {
if (pch_i2c_getack(adap)) {
pch_dbg(adap, "Receive NACK for slave address"
"setting\n");
return -EIO;
}
pch_clrbit(adap->pch_base_address, PCH_I2CSR,
I2CMCF_BIT);
pch_clrbit(adap->pch_base_address, PCH_I2CSR,
I2CMIF_BIT);
} else { /* wait-event timeout */
return -ETIME;
}
}

/* check if this is the last message */
if (last)
pch_i2c_stop(adap);
else
pch_i2c_repstart(adap);
} else {
/* check if this is the last message */
if (last)
pch_i2c_stop(adap);
return -EIO;
}
else
pch_i2c_repstart(adap);

pch_dbg(adap, "return=%d\n", wrcount);

Expand Down Expand Up @@ -512,6 +545,7 @@ static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
u32 addr_2_msb;
u32 addr_8_lsb;
void __iomem *p = adap->pch_base_address;
s32 rtn;

length = msgs->len;
buf = msgs->buf;
Expand Down Expand Up @@ -585,56 +619,79 @@ static s32 pch_i2c_readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
if (first)
pch_i2c_start(adap);

if ((pch_i2c_wait_for_xfer_complete(adap) == 0) &&
(pch_i2c_getack(adap) == 0)) {
pch_dbg(adap, "return %d\n", 0);
rtn = pch_i2c_wait_for_xfer_complete(adap);
if (rtn == 0) {
if (pch_i2c_getack(adap)) {
pch_dbg(adap, "Receive NACK for slave address"
"setting\n");
return -EIO;
}
} else if (rtn == -EIO) { /* Arbitration Lost */
pch_err(adap, "Lost Arbitration\n");
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMAL_BIT);
pch_clrbit(adap->pch_base_address, PCH_I2CSR, I2CMIF_BIT);
return -EAGAIN;
} else { /* wait-event timeout */
return -ETIME;
}

if (length == 0) {
pch_i2c_stop(adap);
ioread32(p + PCH_I2CDR); /* Dummy read needs */
if (length == 0) {
pch_i2c_stop(adap);
ioread32(p + PCH_I2CDR); /* Dummy read needs */

count = length;
} else {
int read_index;
int loop;
pch_i2c_sendack(adap);
count = length;
} else {
int read_index;
int loop;
pch_i2c_sendack(adap);

/* Dummy read */
for (loop = 1, read_index = 0; loop < length; loop++) {
buf[read_index] = ioread32(p + PCH_I2CDR);
/* Dummy read */
for (loop = 1, read_index = 0; loop < length; loop++) {
buf[read_index] = ioread32(p + PCH_I2CDR);

if (loop != 1)
read_index++;
if (loop != 1)
read_index++;

if (pch_i2c_wait_for_xfer_complete(adap) != 0) {
pch_i2c_stop(adap);
return -ETIME;
rtn = pch_i2c_wait_for_xfer_complete(adap);
if (rtn == 0) {
if (pch_i2c_getack(adap)) {
pch_dbg(adap, "Receive NACK for slave"
"address setting\n");
return -EIO;
}
} /* end for */
} else { /* wait-event timeout */
pch_i2c_stop(adap);
return -ETIME;
}

pch_i2c_sendnack(adap);
} /* end for */

buf[read_index] = ioread32(p + PCH_I2CDR);
pch_i2c_sendnack(adap);

if (length != 1)
read_index++;
buf[read_index] = ioread32(p + PCH_I2CDR); /* Read final - 1 */

if (pch_i2c_wait_for_xfer_complete(adap) == 0) {
if (last)
pch_i2c_stop(adap);
else
pch_i2c_repstart(adap);
if (length != 1)
read_index++;

buf[read_index++] = ioread32(p + PCH_I2CDR);
count = read_index;
} else {
count = -ETIME;
rtn = pch_i2c_wait_for_xfer_complete(adap);
if (rtn == 0) {
if (pch_i2c_getack(adap)) {
pch_dbg(adap, "Receive NACK for slave"
"address setting\n");
return -EIO;
}

} else { /* wait-event timeout */
pch_i2c_stop(adap);
return -ETIME;
}
} else {
count = -ETIME;
pch_i2c_stop(adap);

if (last)
pch_i2c_stop(adap);
else
pch_i2c_repstart(adap);

buf[read_index++] = ioread32(p + PCH_I2CDR); /* Read Final */
count = read_index;
}

return count;
Expand Down

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