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Subject[PATCH 4/7 v4] i2c-eg20t: Separate error processing
Date
From: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>

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>
---
drivers/i2c/busses/i2c-eg20t.c | 173 ++++++++++++++++++++++++++-------------
1 files changed, 115 insertions(+), 58 deletions(-)

diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index 6ee719c..0693246 100644
--- a/drivers/i2c/busses/i2c-eg20t.c
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -394,6 +394,7 @@ 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;
@@ -416,11 +417,25 @@ 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;
}
@@ -431,30 +446,48 @@ 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);

@@ -515,6 +548,7 @@ 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;
@@ -588,56 +622,79 @@ 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;
--
1.7.4.4


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