[PATCH v2 8/8] i2c: piix4: Enable EFCH MMIO for Family 17h+

[Terry Bowman]

Enable EFCH MMIO using check for SMBus PCI revision ID value 0x51 or
greater. SMBus PCI revision ID 0x51 is first used by family 17h. This
PCI revision ID check will also enable future AMD processors with the
same EFCH SMBus controller HW.

Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
To: Guenter Roeck <linux@xxxxxxxxxxxx>
To: linux-watchdog@xxxxxxxxxxxxxxx
To: Jean Delvare <jdelvare@xxxxxxxx>
To: linux-i2c@xxxxxxxxxxxxxxx
To: Wolfram Sang <wsa@xxxxxxxxxx>
To: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
To: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx>
Cc: Robert Richter <rrichter@xxxxxxx>
Cc: Thomas Lendacky <thomas.lendacky@xxxxxxx>
---
 drivers/i2c/busses/i2c-piix4.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index b59d2c74abf6..f5533a7d8a13 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -102,6 +102,8 @@
 #define SB800_PIIX4_FCH_PM_ADDR                 0xFED80300
 #define SB800_PIIX4_FCH_PM_SIZE                 8
 
+#define AMD_PCI_SMBUS_REVISION_MMIO             0x51
+
 /* insmod parameters */
 
 /* If force is set to anything different from 0, we forcibly enable the
@@ -229,6 +231,13 @@ static void piix4_sb800_region_release(struct device *dev,
 	}
 }
 
+static bool piix4_sb800_use_mmio(struct pci_dev *PIIX4_dev)
+{
+	return (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
+		PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
+		PIIX4_dev->revision >= AMD_PCI_SMBUS_REVISION_MMIO);
+}
+
 static int piix4_setup(struct pci_dev *PIIX4_dev,
 		       const struct pci_device_id *id)
 {
@@ -339,7 +348,7 @@ static int piix4_setup_sb800_smba(struct pci_dev *PIIX4_dev,
 	u8 smba_en_hi;
 	int retval;
 
-	mmio_cfg.use_mmio = 0;
+	mmio_cfg.use_mmio = piix4_sb800_use_mmio(PIIX4_dev);
 
 	retval = piix4_sb800_region_setup(&PIIX4_dev->dev, &mmio_cfg);
 	if (retval)
-- 
2.30.2