AMD processors include registers capable of selecting between 2 SMBus
ports. Port selection is made during each user access by writing to
FCH::PM::DECODEEN[smbus0sel]. Change the driver to use MMIO during
SMBus port selection because cd6h/cd7h port I/O is not available on
later AMD processors.
Signed-off-by: Terry Bowman <terry.bowman@xxxxxxx>
---
drivers/i2c/busses/i2c-piix4.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index a23c0327e1f6..c5325cadaf55 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -752,10 +752,19 @@ static void piix4_imc_wakeup(void)
release_region(KERNCZ_IMC_IDX, 2);
}
-static int piix4_sb800_port_sel(u8 port)
+static int piix4_sb800_port_sel(u8 port, struct sb800_mmio_cfg *mmio_cfg)
{
u8 smba_en_lo, val;
+ if (mmio_cfg->use_mmio) {
+ smba_en_lo = ioread8(mmio_cfg->addr + piix4_port_sel_sb800);
+ val = (smba_en_lo & ~piix4_port_mask_sb800) | port;
+ if (smba_en_lo != val)
+ iowrite8(val, mmio_cfg->addr + piix4_port_sel_sb800);
+
+ return (smba_en_lo & piix4_port_mask_sb800);
+ }
+
outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
@@ -765,6 +774,7 @@ static int piix4_sb800_port_sel(u8 port)
return (smba_en_lo & piix4_port_mask_sb800);
}
+
/*
* Handles access to multiple SMBus ports on the SB800.
* The port is selected by bits 2:1 of the smb_en register (0x2c).
@@ -841,12 +851,12 @@ static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
}
}
- prev_port = piix4_sb800_port_sel(adapdata->port);
+ prev_port = piix4_sb800_port_sel(adapdata->port, &adapdata->mmio_cfg);
retval = piix4_access(adap, addr, flags, read_write,
command, size, data);
- piix4_sb800_port_sel(prev_port);
+ piix4_sb800_port_sel(prev_port, &adapdata->mmio_cfg);
/* Release the semaphore */
outb_p(smbslvcnt | 0x20, SMBSLVCNT);
--
2.30.2
