From 0fe16195f89173652cf111d7b384941b00c5aabd Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Sat, 15 Jul 2017 16:51:26 -0700
Subject: [PATCH] i2c: piix4: Fix SMBus port selection for AMD Family 17h chips
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Git-commit: 0fe16195f89173652cf111d7b384941b00c5aabd
Patch-mainline: v4.14-rc6
References: bsc#1051510

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
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/i2c/busses/i2c-piix4.c |   30 ++++++++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

--- 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_
  */
 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_
 
 	/* 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_
 		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
 	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_
 
 	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;