i2c: piix4: Fix SMBus port selection for AMD Family 17h chips

AMD Family 17h uses the KERNCZ SMBus controller. While its documentation
is not publicly available, it is documented in the BIOS and Kernel
Developer’s Guide for AMD Family 15h Models 60h-6Fh Processors.

On this SMBus controller, the port select register is at PMx register
0x02, bit 4:3 (PMx00 register bit 20:19).

Without this patch, the 4 SMBus channels on AMD Family 17h chips are
mirrored and report the same chips on all channels.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 0ecdb47a23abcbf9691bf809b126d72d6c3a46f8..01f767ee45466242b3ea2f785049fda98988421e 100644 (file)
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -94,6 +94,12 @@
 #define SB800_PIIX4_PORT_IDX_ALT       0x2e
 #define SB800_PIIX4_PORT_IDX_SEL       0x2f
 #define SB800_PIIX4_PORT_IDX_MASK      0x06
+#define SB800_PIIX4_PORT_IDX_SHIFT     1
+
+/* On kerncz, SmBus0Sel is at bit 20:19 of PMx00 DecodeEn */
+#define SB800_PIIX4_PORT_IDX_KERNCZ            0x02
+#define SB800_PIIX4_PORT_IDX_MASK_KERNCZ       0x18
+#define SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ      3
 
 /* insmod parameters */
 
@@ -149,6 +155,8 @@ static const struct dmi_system_id piix4_dmi_ibm[] = {
  */
 static DEFINE_MUTEX(piix4_mutex_sb800);
 static u8 piix4_port_sel_sb800;
+static u8 piix4_port_mask_sb800;
+static u8 piix4_port_shift_sb800;
 static const char *piix4_main_port_names_sb800[PIIX4_MAX_ADAPTERS] = {
        " port 0", " port 2", " port 3", " port 4"
 };
@@ -347,7 +355,19 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 
        /* Find which register is used for port selection */
        if (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD) {
-               piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_ALT;
+               switch (PIIX4_dev->device) {
+               case PCI_DEVICE_ID_AMD_KERNCZ_SMBUS:
+                       piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_KERNCZ;
+                       piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK_KERNCZ;
+                       piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ;
+                       break;
+               case PCI_DEVICE_ID_AMD_HUDSON2_SMBUS:
+               default:
+                       piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_ALT;
+                       piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK;
+                       piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT;
+                       break;
+               }
        } else {
                mutex_lock(&piix4_mutex_sb800);
                outb_p(SB800_PIIX4_PORT_IDX_SEL, SB800_PIIX4_SMB_IDX);
@@ -355,6 +375,8 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
                piix4_port_sel_sb800 = (port_sel & 0x01) ?
                                       SB800_PIIX4_PORT_IDX_ALT :
                                       SB800_PIIX4_PORT_IDX;
+               piix4_port_mask_sb800 = SB800_PIIX4_PORT_IDX_MASK;
+               piix4_port_shift_sb800 = SB800_PIIX4_PORT_IDX_SHIFT;
                mutex_unlock(&piix4_mutex_sb800);
        }
 
@@ -616,8 +638,8 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
        smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
 
        port = adapdata->port;
-       if ((smba_en_lo & SB800_PIIX4_PORT_IDX_MASK) != port)
-               outb_p((smba_en_lo & ~SB800_PIIX4_PORT_IDX_MASK) | port,
+       if ((smba_en_lo & piix4_port_mask_sb800) != port)
+               outb_p((smba_en_lo & ~piix4_port_mask_sb800) | port,
                       SB800_PIIX4_SMB_IDX + 1);
 
        retval = piix4_access(adap, addr, flags, read_write,
@@ -706,7 +728,7 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
 
        adapdata->smba = smba;
        adapdata->sb800_main = sb800_main;
-       adapdata->port = port << 1;
+       adapdata->port = port << piix4_port_shift_sb800;
 
        /* set up the sysfs linkage to our parent device */
        adap->dev.parent = &dev->dev;