diff options
| author | Terry Bowman <terry.bowman@amd.com> | 2022-02-09 11:27:16 -0600 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2022-02-11 15:38:22 +0100 |
| commit | 381a3083c6747ae5cdbef9b176d57d1b966db49f (patch) | |
| tree | 2ae1ec4f0f3e67bc8906baea656a1b9f9e242af9 /drivers/i2c | |
| parent | 46967bc1ee93acd1d8953c87dc16f43de4076f93 (diff) | |
| download | lwn-381a3083c6747ae5cdbef9b176d57d1b966db49f.tar.gz lwn-381a3083c6747ae5cdbef9b176d57d1b966db49f.zip | |
i2c: piix4: Add EFCH MMIO support for SMBus port select
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@amd.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-piix4.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c index 7f312177eb27..4789fc9ad270 100644 --- a/drivers/i2c/busses/i2c-piix4.c +++ b/drivers/i2c/busses/i2c-piix4.c @@ -753,10 +753,19 @@ 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); @@ -843,12 +852,12 @@ 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); |