i2c-eg20t: Separate error processing

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>

1 files changed, 115 insertions, 58 deletions

diff --git a/drivers/i2c/busses/i2c-eg20t.c b/drivers/i2c/busses/i2c-eg20t.c
index 38e44d959f00..cb296862ae0a 100644
--- a/drivers/i2c/busses/i2c-eg20t.c
+++ b/drivers/i2c/busses/i2c-eg20t.c
@@ -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;
@@ -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;
                 }
@@ -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);
 
@@ -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;
@@ -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;