i2c: sh_mobile: improve error handling

Use standard i2c error codes for i2c failures. Also, don't print
something on timeout since it happens regularly with i2c. Simplify some,
logic, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
(cherry picked from commit 5a72b25e7896e6358b62b590ce5b3a457516ae40)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index d91625e..d2fa222 100644 (file)
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -480,7 +480,7 @@ static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
 {
        if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
                dev_err(pd->dev, "Unsupported zero length i2c read\n");
-               return -EIO;
+               return -EOPNOTSUPP;
        }
 
        if (do_init) {
@@ -515,17 +515,12 @@ static int poll_dte(struct sh_mobile_i2c_data *pd)
                        break;
 
                if (val & ICSR_TACK)
-                       return -EIO;
+                       return -ENXIO;
 
                udelay(10);
        }
 
-       if (!i) {
-               dev_warn(pd->dev, "Timeout polling for DTE!\n");
-               return -ETIMEDOUT;
-       }
-
-       return 0;
+       return i ? 0 : -ETIMEDOUT;
 }
 
 static int poll_busy(struct sh_mobile_i2c_data *pd)
@@ -543,20 +538,18 @@ static int poll_busy(struct sh_mobile_i2c_data *pd)
                 */
                if (!(val & ICSR_BUSY)) {
                        /* handle missing acknowledge and arbitration lost */
-                       if ((val | pd->sr) & (ICSR_TACK | ICSR_AL))
-                               return -EIO;
+                       val |= pd->sr;
+                       if (val & ICSR_TACK)
+                               return -ENXIO;
+                       if (val & ICSR_AL)
+                               return -EAGAIN;
                        break;
                }
 
                udelay(10);
        }
 
-       if (!i) {
-               dev_err(pd->dev, "Polling timed out\n");
-               return -ETIMEDOUT;
-       }
-
-       return 0;
+       return i ? 0 : -ETIMEDOUT;
 }
 
 static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,