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, 13 insertions, 12 deletions

diff --git a/drivers/i2c/busses/i2c-nforce2.c b/drivers/i2c/busses/i2c-nforce2.c
index f95efff9b3d1..081fdf3393f4 100644
--- a/drivers/i2c/busses/i2c-nforce2.c
+++ b/drivers/i2c/busses/i2c-nforce2.c
@@ -172,16 +172,16 @@ static int nforce2_check_status(struct i2c_adapter *adap)
 		dev_dbg(&adap->dev, "SMBus Timeout!\n");
 		if (smbus->can_abort)
 			nforce2_abort(adap);
-		return -1;
+		return -ETIMEDOUT;
 	}
 	if (!(temp & NVIDIA_SMB_STS_DONE) || (temp & NVIDIA_SMB_STS_STATUS)) {
 		dev_dbg(&adap->dev, "Transaction failed (0x%02x)!\n", temp);
-		return -1;
+		return -EIO;
 	}
 	return 0;
 }
 
-/* Return -1 on error */
+/* Return negative errno on error */
 static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
 		unsigned short flags, char read_write,
 		u8 command, int size, union i2c_smbus_data * data)
@@ -189,7 +189,7 @@ static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
 	struct nforce2_smbus *smbus = adap->algo_data;
 	unsigned char protocol, pec;
 	u8 len;
-	int i;
+	int i, status;
 
 	protocol = (read_write == I2C_SMBUS_READ) ? NVIDIA_SMB_PRTCL_READ :
 		NVIDIA_SMB_PRTCL_WRITE;
@@ -233,7 +233,7 @@ static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
 						"Transaction failed "
 						"(requested block size: %d)\n",
 						len);
-					return -1;
+					return -EINVAL;
 				}
 				outb_p(len, NVIDIA_SMB_BCNT);
 				for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
@@ -245,14 +245,15 @@ static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
 
 		default:
 			dev_err(&adap->dev, "Unsupported transaction %d\n", size);
-			return -1;
+			return -EOPNOTSUPP;
 	}
 
 	outb_p((addr & 0x7f) << 1, NVIDIA_SMB_ADDR);
 	outb_p(protocol, NVIDIA_SMB_PRTCL);
 
-	if (nforce2_check_status(adap))
-		return -1;
+	status = nforce2_check_status(adap);
+	if (status)
+		return status;
 
 	if (read_write == I2C_SMBUS_WRITE)
 		return 0;
@@ -274,7 +275,7 @@ static s32 nforce2_access(struct i2c_adapter * adap, u16 addr,
 				dev_err(&adap->dev, "Transaction failed "
 					"(received block size: 0x%02x)\n",
 					len);
-				return -1;
+				return -EPROTO;
 			}
 			for (i = 0; i < len; i++)
 				data->block[i+1] = inb_p(NVIDIA_SMB_DATA + i);
@@ -335,7 +336,7 @@ static int __devinit nforce2_probe_smb (struct pci_dev *dev, int bar,
 		    != PCIBIOS_SUCCESSFUL) {
 			dev_err(&dev->dev, "Error reading PCI config for %s\n",
 				name);
-			return -1;
+			return -EIO;
 		}
 
 		smbus->base = iobase & PCI_BASE_ADDRESS_IO_MASK;
@@ -345,7 +346,7 @@ static int __devinit nforce2_probe_smb (struct pci_dev *dev, int bar,
 	if (!request_region(smbus->base, smbus->size, nforce2_driver.name)) {
 		dev_err(&smbus->adapter.dev, "Error requesting region %02x .. %02X for %s\n",
 			smbus->base, smbus->base+smbus->size-1, name);
-		return -1;
+		return -EBUSY;
 	}
 	smbus->adapter.owner = THIS_MODULE;
 	smbus->adapter.id = I2C_HW_SMBUS_NFORCE2;
@@ -360,7 +361,7 @@ static int __devinit nforce2_probe_smb (struct pci_dev *dev, int bar,
 	if (error) {
 		dev_err(&smbus->adapter.dev, "Failed to register adapter.\n");
 		release_region(smbus->base, smbus->size);
-		return -1;
+		return error;
 	}
 	dev_info(&smbus->adapter.dev, "nForce2 SMBus adapter at %#x\n", smbus->base);
 	return 0;