[PATCH v2 6/8] i2c: piix4: Add EFCH MMIO support to SMBus base address detect

From: Terry Bowman
Date: Tue Jan 18 2022 - 17:13:22 EST


The EFCH SMBus controller's base address is determined using details in
FCH::PM::DECODEEN[smbusasfiobase] and FCH::PM::DECODEEN[smbusasfioen].
This code also writes to FCH::PM::ISACONTROL[mmioen] to enable MMIO
decoding. These register fields were accessed using cd6h/cd7h port I/O.
cd6h/cd7h port I/O is no longer available in later AMD processors.
Change base address detection to use MMIO instead of port I/O cd6h/cd7h.

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 | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index ffb1367dd852..2937f3254c31 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -98,6 +98,7 @@
#define SB800_PIIX4_PORT_IDX_MASK_KERNCZ 0x18
#define SB800_PIIX4_PORT_IDX_SHIFT_KERNCZ 3

+#define SB800_PIIX4_FCH_PM_DECODEEN_MMIO BIT(1)
#define SB800_PIIX4_FCH_PM_ADDR 0xFED80300
#define SB800_PIIX4_FCH_PM_SIZE 8

@@ -344,10 +345,18 @@ static int piix4_setup_sb800_smba(struct pci_dev *PIIX4_dev,
if (retval)
return retval;

- outb_p(smb_en, SB800_PIIX4_SMB_IDX);
- smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
- outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX);
- smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1);
+ if (mmio_cfg.use_mmio) {
+ iowrite32(ioread32(mmio_cfg.addr + 4) | SB800_PIIX4_FCH_PM_DECODEEN_MMIO,
+ mmio_cfg.addr + 4);
+
+ smba_en_lo = ioread8(mmio_cfg.addr);
+ smba_en_hi = ioread8(mmio_cfg.addr + 1);
+ } else {
+ outb_p(smb_en, SB800_PIIX4_SMB_IDX);
+ smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
+ outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX);
+ smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1);
+ }

piix4_sb800_region_release(&PIIX4_dev->dev, &mmio_cfg);

--
2.30.2