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, 23 insertions, 21 deletions

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index b0f771fe4326..7d6d9dfcc58a 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -151,7 +151,7 @@ static int i801_transaction(int xact)
                 outb_p(temp, SMBHSTSTS);
                 if ((temp = (0x1f & inb_p(SMBHSTSTS))) != 0x00) {
                         dev_dbg(&I801_dev->dev, "Failed! (%02x)\n", temp);
-                        return -1;
+                        return -EBUSY;
                 } else {
                         dev_dbg(&I801_dev->dev, "Successful!\n");
                 }
@@ -170,7 +170,7 @@ static int i801_transaction(int xact)
         /* If the SMBus is still busy, we give up */
         if (timeout >= MAX_TIMEOUT) {
                 dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
-                result = -1;
+                result = -ETIMEDOUT;
                 /* try to stop the current command */
                 dev_dbg(&I801_dev->dev, "Terminating the current operation\n");
                 outb_p(inb_p(SMBHSTCNT) | SMBHSTCNT_KILL, SMBHSTCNT);
@@ -179,19 +179,19 @@ static int i801_transaction(int xact)
         }
 
         if (temp & SMBHSTSTS_FAILED) {
-                result = -1;
+                result = -EIO;
                 dev_dbg(&I801_dev->dev, "Error: Failed bus transaction\n");
         }
 
         if (temp & SMBHSTSTS_BUS_ERR) {
-                result = -1;
+                result = -EIO;
                 dev_err(&I801_dev->dev, "Bus collision! SMBus may be locked "
                         "until next hard reset. (sorry!)\n");
                 /* Clock stops and slave is stuck in mid-transmission */
         }
 
         if (temp & SMBHSTSTS_DEV_ERR) {
-                result = -1;
+                result = -ENXIO;
                 dev_dbg(&I801_dev->dev, "Error: no response!\n");
         }
 
@@ -231,6 +231,7 @@ static int i801_block_transaction_by_block(union i2c_smbus_data *data,
                                            char read_write, int hwpec)
 {
         int i, len;
+        int status;
 
         inb_p(SMBHSTCNT); /* reset the data buffer index */
 
@@ -242,14 +243,15 @@ static int i801_block_transaction_by_block(union i2c_smbus_data *data,
                         outb_p(data->block[i+1], SMBBLKDAT);
         }
 
-        if (i801_transaction(I801_BLOCK_DATA | ENABLE_INT9 |
-                             I801_PEC_EN * hwpec))
-                return -1;
+        status = i801_transaction(I801_BLOCK_DATA | ENABLE_INT9 |
+                                  I801_PEC_EN * hwpec);
+        if (status)
+                return status;
 
         if (read_write == I2C_SMBUS_READ) {
                 len = inb_p(SMBHSTDAT0);
                 if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
-                        return -1;
+                        return -EPROTO;
 
                 data->block[0] = len;
                 for (i = 0; i < len; i++)
@@ -314,11 +316,11 @@ static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
                         if (((temp = inb_p(SMBHSTSTS)) & errmask) != 0x00) {
                                 dev_err(&I801_dev->dev,
                                         "Reset failed! (%02x)\n", temp);
-                                return -1;
+                                return -EBUSY;
                         }
                         if (i != 1)
                                 /* if die in middle of block transaction, fail */
-                                return -1;
+                                return -EIO;
                 }
 
                 if (i == 1)
@@ -342,19 +344,19 @@ static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
                         msleep(1);
                         outb_p(inb_p(SMBHSTCNT) & (~SMBHSTCNT_KILL),
                                 SMBHSTCNT);
-                        result = -1;
+                        result = -ETIMEDOUT;
                         dev_dbg(&I801_dev->dev, "SMBus Timeout!\n");
                 }
 
                 if (temp & SMBHSTSTS_FAILED) {
-                        result = -1;
+                        result = -EIO;
                         dev_dbg(&I801_dev->dev,
                                 "Error: Failed bus transaction\n");
                 } else if (temp & SMBHSTSTS_BUS_ERR) {
-                        result = -1;
+                        result = -EIO;
                         dev_err(&I801_dev->dev, "Bus collision!\n");
                 } else if (temp & SMBHSTSTS_DEV_ERR) {
-                        result = -1;
+                        result = -ENXIO;
                         dev_dbg(&I801_dev->dev, "Error: no response!\n");
                 }
 
@@ -362,7 +364,7 @@ static int i801_block_transaction_byte_by_byte(union i2c_smbus_data *data,
                  && command != I2C_SMBUS_I2C_BLOCK_DATA) {
                         len = inb_p(SMBHSTDAT0);
                         if (len < 1 || len > I2C_SMBUS_BLOCK_MAX)
-                                return -1;
+                                return -EPROTO;
                         data->block[0] = len;
                 }
 
@@ -394,7 +396,7 @@ static int i801_set_block_buffer_mode(void)
 {
         outb_p(inb_p(SMBAUXCTL) | SMBAUXCTL_E32B, SMBAUXCTL);
         if ((inb_p(SMBAUXCTL) & SMBAUXCTL_E32B) == 0)
-                return -1;
+                return -EIO;
         return 0;
 }
 
@@ -414,7 +416,7 @@ static int i801_block_transaction(union i2c_smbus_data *data, char read_write,
                 } else if (!(i801_features & FEATURE_I2C_BLOCK_READ)) {
                         dev_err(&I801_dev->dev,
                                 "I2C block read is unsupported!\n");
-                        return -1;
+                        return -EOPNOTSUPP;
                 }
         }
 
@@ -449,7 +451,7 @@ static int i801_block_transaction(union i2c_smbus_data *data, char read_write,
         return result;
 }
 
-/* Return -1 on error. */
+/* Return negative errno on error. */
 static s32 i801_access(struct i2c_adapter * adap, u16 addr,
                        unsigned short flags, char read_write, u8 command,
                        int size, union i2c_smbus_data * data)
@@ -514,7 +516,7 @@ static s32 i801_access(struct i2c_adapter * adap, u16 addr,
         case I2C_SMBUS_PROC_CALL:
         default:
                 dev_err(&I801_dev->dev, "Unsupported transaction %d\n", size);
-                return -1;
+                return -EOPNOTSUPP;
         }
 
         if (hwpec)      /* enable/disable hardware PEC */
@@ -537,7 +539,7 @@ static s32 i801_access(struct i2c_adapter * adap, u16 addr,
         if(block)
                 return ret;
         if(ret)
-                return -1;
+                return ret;
         if ((read_write == I2C_SMBUS_WRITE) || (xact == I801_QUICK))
                 return 0;