i2c: Fix oops on bus multiplexer driver loading

[linux-2.6-omap-h63xx.git] / drivers / i2c / busses / i2c-amd756-s4882.c

diff --git a/drivers/i2c/busses/i2c-amd756-s4882.c b/drivers/i2c/busses/i2c-amd756-s4882.c
index 2f150e33c74c9b19ae6f93dc6e1828ebd619d933..8ba2bcf727d31a3ed725a2a9a0baf5a506046da8 100644 (file)
--- a/drivers/i2c/busses/i2c-amd756-s4882.c
+++ b/drivers/i2c/busses/i2c-amd756-s4882.c
@@ -155,14 +155,23 @@ static int __init amd756_s4882_init(void)
        int i, error;
        union i2c_smbus_data ioconfig;
 
+       if (!amd756_smbus.dev.parent)
+               return -ENODEV;
+
+       /* Configure the PCA9556 multiplexer */
+       ioconfig.byte = 0x00; /* All I/O to output mode */
+       error = i2c_smbus_xfer(&amd756_smbus, 0x18, 0, I2C_SMBUS_WRITE, 0x03,
+                              I2C_SMBUS_BYTE_DATA, &ioconfig);
+       if (error) {
+               dev_err(&amd756_smbus.dev, "PCA9556 configuration failed\n");
+               error = -EIO;
+               goto ERROR0;
+       }
+
        /* Unregister physical bus */
        error = i2c_del_adapter(&amd756_smbus);
        if (error) {
-               if (error == -EINVAL)
-                       error = -ENODEV;
-               else
-                       dev_err(&amd756_smbus.dev, "Physical bus removal "
-                               "failed\n");
+               dev_err(&amd756_smbus.dev, "Physical bus removal failed\n");
                goto ERROR0;
        }
 
@@ -198,22 +207,11 @@ static int __init amd756_s4882_init(void)
        s4882_algo[3].smbus_xfer = amd756_access_virt3;
        s4882_algo[4].smbus_xfer = amd756_access_virt4;
 
-       /* Configure the PCA9556 multiplexer */
-       ioconfig.byte = 0x00; /* All I/O to output mode */
-       error = amd756_smbus.algo->smbus_xfer(&amd756_smbus, 0x18, 0,
-                                             I2C_SMBUS_WRITE, 0x03,
-                                             I2C_SMBUS_BYTE_DATA, &ioconfig);
-       if (error) {
-               dev_err(&amd756_smbus.dev, "PCA9556 configuration failed\n");
-               error = -EIO;
-               goto ERROR3;
-       }
-
        /* Register virtual adapters */
        for (i = 0; i < 5; i++) {
                error = i2c_add_adapter(s4882_adapter+i);
                if (error) {
-                       dev_err(&amd756_smbus.dev,
+                       printk(KERN_ERR "i2c-amd756-s4882: "
                               "Virtual adapter %d registration "
                               "failed, module not inserted\n", i);
                        for (i--; i >= 0; i--)
@@ -252,8 +250,8 @@ static void __exit amd756_s4882_exit(void)
 
        /* Restore physical bus */
        if (i2c_add_adapter(&amd756_smbus))
-               dev_err(&amd756_smbus.dev, "Physical bus restoration "
-                       "failed\n");
+               printk(KERN_ERR "i2c-amd756-s4882: "
+                      "Physical bus restoration failed\n");
 }
 
 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");