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>
diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4
index 475bb4a..1e6634f 100644
--- a/Documentation/i2c/busses/i2c-piix4
+++ b/Documentation/i2c/busses/i2c-piix4
@@ -8,6 +8,11 @@
Datasheet: Only available via NDA from ServerWorks
* ATI IXP200, IXP300, IXP400, SB600, SB700 and SB800 southbridges
Datasheet: Not publicly available
+ SB700 register reference available at:
+ http://support.amd.com/us/Embedded_TechDocs/43009_sb7xx_rrg_pub_1.00.pdf
+ * AMD SP5100 (SB700 derivative found on some server mainboards)
+ Datasheet: Publicly available at the AMD website
+ http://support.amd.com/us/Embedded_TechDocs/44413.pdf
* AMD Hudson-2
Datasheet: Not publicly available
* Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge
@@ -68,6 +73,10 @@
The ServerWorks Southbridges, the Intel 440MX, and the Victory66 are
identical to the PIIX4 in I2C/SMBus support.
+The AMD SB700 and SP5100 chipsets implement two PIIX4-compatible SMBus
+controllers. If your BIOS initializes the secondary controller, it will
+be detected by this driver as an "Auxiliary SMBus Host Controller".
+
If you own Force CPCI735 motherboard or other OSB4 based systems you may need
to change the SMBus Interrupt Select register so the SMBus controller uses
the SMI mode.
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7244c8b..2e7530a 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -133,7 +133,7 @@
ATI IXP300
ATI IXP400
ATI SB600
- ATI SB700
+ ATI SB700/SP5100
ATI SB800
AMD Hudson-2
Serverworks OSB4
@@ -143,6 +143,10 @@
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.
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 42ed0af..ef511df 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -21,11 +21,12 @@
Supports:
Intel PIIX4, 440MX
Serverworks OSB4, CSB5, CSB6, HT-1000, HT-1100
- ATI IXP200, IXP300, IXP400, SB600, SB700, SB800
+ ATI IXP200, IXP300, IXP400, SB600, SB700/SP5100, SB800
AMD Hudson-2
SMSC Victory66
- Note: we assume there can only be one device, with one SMBus interface.
+ Note: we assume there can only be one device, with one or more
+ SMBus interfaces.
*/
#include <linux/module.h>
@@ -293,6 +294,46 @@
return piix4_smba;
}
+static int __devinit piix4_setup_aux(struct pci_dev *PIIX4_dev,
+ const struct pci_device_id *id,
+ unsigned short base_reg_addr)
+{
+ /* Set up auxiliary SMBus controllers found on some
+ * AMD chipsets e.g. SP5100 (SB700 derivative) */
+
+ unsigned short piix4_smba;
+
+ /* Read address of auxiliary SMBus controller */
+ pci_read_config_word(PIIX4_dev, base_reg_addr, &piix4_smba);
+ if ((piix4_smba & 1) == 0) {
+ dev_dbg(&PIIX4_dev->dev,
+ "Auxiliary SMBus controller not enabled\n");
+ return -ENODEV;
+ }
+
+ piix4_smba &= 0xfff0;
+ if (piix4_smba == 0) {
+ dev_dbg(&PIIX4_dev->dev,
+ "Auxiliary SMBus base address uninitialized\n");
+ return -ENODEV;
+ }
+
+ if (acpi_check_region(piix4_smba, SMBIOSIZE, piix4_driver.name))
+ return -ENODEV;
+
+ if (!request_region(piix4_smba, SMBIOSIZE, piix4_driver.name)) {
+ dev_err(&PIIX4_dev->dev, "Auxiliary SMBus region 0x%x "
+ "already in use!\n", piix4_smba);
+ return -EBUSY;
+ }
+
+ dev_info(&PIIX4_dev->dev,
+ "Auxiliary SMBus Host Controller at 0x%x\n",
+ piix4_smba);
+
+ return piix4_smba;
+}
+
static int piix4_transaction(struct i2c_adapter *piix4_adapter)
{
struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(piix4_adapter);
@@ -497,6 +538,7 @@
MODULE_DEVICE_TABLE (pci, piix4_ids);
static struct i2c_adapter *piix4_main_adapter;
+static struct i2c_adapter *piix4_aux_adapter;
static int __devinit piix4_add_adapter(struct pci_dev *dev,
unsigned short smba,
@@ -560,10 +602,28 @@
else
retval = piix4_setup(dev, id);
+ /* If no main SMBus found, give up */
if (retval < 0)
return retval;
- return piix4_add_adapter(dev, retval, &piix4_main_adapter);
+ /* Try to register main SMBus adapter, give up if we can't */
+ retval = piix4_add_adapter(dev, retval, &piix4_main_adapter);
+ if (retval < 0)
+ return retval;
+
+ /* Check for auxiliary SMBus on some AMD chipsets */
+ if (dev->vendor == PCI_VENDOR_ID_ATI &&
+ dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
+ dev->revision < 0x40) {
+ retval = piix4_setup_aux(dev, id, 0x58);
+ if (retval > 0) {
+ /* Try to add the aux adapter if it exists,
+ * piix4_add_adapter will clean up if this fails */
+ piix4_add_adapter(dev, retval, &piix4_aux_adapter);
+ }
+ }
+
+ return 0;
}
static void __devexit piix4_adap_remove(struct i2c_adapter *adap)
@@ -584,6 +644,11 @@
piix4_adap_remove(piix4_main_adapter);
piix4_main_adapter = NULL;
}
+
+ if (piix4_aux_adapter) {
+ piix4_adap_remove(piix4_aux_adapter);
+ piix4_aux_adapter = NULL;
+ }
}
static struct pci_driver piix4_driver = {