diff options
Diffstat (limited to 'src/soc/intel/apollolake/bootblock/bootblock.c')
| -rw-r--r-- | src/soc/intel/apollolake/bootblock/bootblock.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/soc/intel/apollolake/bootblock/bootblock.c b/src/soc/intel/apollolake/bootblock/bootblock.c index cd23f5984b..77d98d98be 100644 --- a/src/soc/intel/apollolake/bootblock/bootblock.c +++ b/src/soc/intel/apollolake/bootblock/bootblock.c @@ -41,8 +41,13 @@ static void enable_pm_timer(void) { /* ACPI PM timer emulation */ msr_t msr; - /* Multiplier value that somehow 3.579545MHz freq */ - msr.hi = 0x2FBA2E25; + /* + * The derived frequency is calculated as follows: + * (CTC_FREQ * msr[63:32]) >> 32 = target frequency. + * Back solve the multiplier so the 3.579545MHz ACPI timer + * frequency is used. + */ + msr.hi = (3579545ULL << 32) / CTC_FREQ; /* Set PM1 timer IO port and enable*/ msr.lo = EMULATE_PM_TMR_EN | (ACPI_PMIO_BASE + R_ACPI_PM1_TMR); wrmsr(MSR_EMULATE_PM_TMR, msr); |