i2c-piix4: Support AMD auxiliary SMBus controller

Some AMD chipsets, such as the SP5100, have an auxiliary SMBus
controller with a second set of registers. This patch adds
support for this auxiliary controller.

Tested on ASUS KCMA-D8 motherboard.

Signed-off-by: Andrew Armenia <andrew@asquaredlabs.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7244c8be6063..2e7530a4e7b8 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -133,7 +133,7 @@ config I2C_PIIX4
             ATI IXP300
             ATI IXP400
             ATI SB600
-            ATI SB700
+            ATI SB700/SP5100
             ATI SB800
             AMD Hudson-2
             Serverworks OSB4
@@ -143,6 +143,10 @@ config I2C_PIIX4
             Serverworks HT-1100
             SMSC Victory66
 
+          Some AMD chipsets contain two PIIX4-compatible SMBus
+          controllers. This driver will attempt to use both controllers
+          on the SB700/SP5100, if they have been initialized by the BIOS.
+
           This driver can also be built as a module.  If so, the module
           will be called i2c-piix4.