i2c: Bus drivers return -Errno not -1

Tighten error paths used by various i2c adapters (mostly x86) so
they return real fault/errno codes instead of a "-1" (which is
most often interpreted as "-EPERM").  Build tested, with eyeball
review.

One minor initial goal is to have adapters consistently return
the code "-ENXIO" when addressing a device doesn't get an ACK
response, at least in the probe paths where they are already
good at stifling related logspam.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 10 insertions, 9 deletions

diff --git a/drivers/i2c/busses/i2c-ali15x3.c b/drivers/i2c/busses/i2c-ali15x3.c
index 93bf87d70961..3d752561dc37 100644
--- a/drivers/i2c/busses/i2c-ali15x3.c
+++ b/drivers/i2c/busses/i2c-ali15x3.c
@@ -282,7 +282,7 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
                         dev_err(&adap->dev, "SMBus reset failed! (0x%02x) - "
                                 "controller or device on bus is probably hung\n",
                                 temp);
-                        return -1;
+                        return -EBUSY;
                 }
         } else {
                 /* check and clear done bit */
@@ -304,12 +304,12 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
 
         /* If the SMBus is still busy, we give up */
         if (timeout >= MAX_TIMEOUT) {
-                result = -1;
+                result = -ETIMEDOUT;
                 dev_err(&adap->dev, "SMBus Timeout!\n");
         }
 
         if (temp & ALI15X3_STS_TERM) {
-                result = -1;
+                result = -EIO;
                 dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
         }
 
@@ -320,7 +320,7 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
           This means that bus collisions go unreported.
         */
         if (temp & ALI15X3_STS_COLL) {
-                result = -1;
+                result = -ENXIO;
                 dev_dbg(&adap->dev,
                         "Error: no response or bus collision ADD=%02x\n",
                         inb_p(SMBHSTADD));
@@ -328,7 +328,7 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
 
         /* haven't ever seen this */
         if (temp & ALI15X3_STS_DEV) {
-                result = -1;
+                result = -EIO;
                 dev_err(&adap->dev, "Error: device error\n");
         }
         dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
@@ -338,7 +338,7 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
         return result;
 }
 
-/* Return -1 on error. */
+/* Return negative errno on error. */
 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
                    unsigned short flags, char read_write, u8 command,
                    int size, union i2c_smbus_data * data)
@@ -364,7 +364,7 @@ static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
         switch (size) {
         case I2C_SMBUS_PROC_CALL:
                 dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
-                return -1;
+                return -EOPNOTSUPP;
         case I2C_SMBUS_QUICK:
                 outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
                        SMBHSTADD);
@@ -421,8 +421,9 @@ static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
 
         outb_p(size, SMBHSTCNT);        /* output command */
 
-        if (ali15x3_transaction(adap))  /* Error in transaction */
-                return -1;
+        temp = ali15x3_transaction(adap);
+        if (temp)
+                return temp;
 
         if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
                 return 0;