diff options
Diffstat (limited to 'src/southbridge/amd/cimx/sb800/bootblock.c')
| -rw-r--r-- | src/southbridge/amd/cimx/sb800/bootblock.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/southbridge/amd/cimx/sb800/bootblock.c b/src/southbridge/amd/cimx/sb800/bootblock.c index 8ed198a9e4..d21b4fdbfd 100644 --- a/src/southbridge/amd/cimx/sb800/bootblock.c +++ b/src/southbridge/amd/cimx/sb800/bootblock.c @@ -97,10 +97,17 @@ static void enable_clocks(void) reg8 &= ~(1 << 1); outb(reg8, 0xCD7); - // Program SB800 MiscCntrl Device_CLK1_sel for 48 MHz (default is 14 MHz) + // Program SB800 MiscClkCntrl register to configure clock output on the + // 14M_25M_48M_OSC ball usually used for the Super-I/O. + // Almost all SIOs need 48 MHz, only the SMSC SCH311x wants 14 MHz, + // which is the SB800's power up default. We could switch back to 14 + // in the mainboard's romstage.c, but then the clock frequency would + // change twice. reg32 = *acpi_mmio; - reg32 &= ~((1 << 0) | (1 << 2)); - reg32 |= 1 << 1; + reg32 &= ~((1 << 2) | (3 << 0)); // enable, 14 MHz (power up default) +#if !CONFIG_SUPERIO_WANTS_14MHZ_CLOCK + reg32 |= 2 << 0; // Device_CLK1_sel = 48 MHz +#endif *acpi_mmio = reg32; } |