diff options
Diffstat (limited to 'src/soc/intel/braswell/tsc_freq.c')
| -rw-r--r-- | src/soc/intel/braswell/tsc_freq.c | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/src/soc/intel/braswell/tsc_freq.c b/src/soc/intel/braswell/tsc_freq.c index 284ba2b23e..fff882eb9b 100644 --- a/src/soc/intel/braswell/tsc_freq.c +++ b/src/soc/intel/braswell/tsc_freq.c @@ -26,12 +26,38 @@ #endif #include <stdint.h> +static const unsigned int cpu_bus_clk_freq_table[] = { + 83333, + 100000, + 133333, + 116666, + 80000, + 93333, + 90000, + 88900, + 87500 +}; + +unsigned int cpu_bus_freq_khz(void) +{ + msr_t clk_info = rdmsr(MSR_BSEL_CR_OVERCLOCK_CONTROL); + if((clk_info.lo & 0xF) < (sizeof(cpu_bus_clk_freq_table)/sizeof(unsigned int))) + { + return(cpu_bus_clk_freq_table[clk_info.lo & 0xF]); + } + return 0; +} + unsigned long tsc_freq_mhz(void) { - msr_t ia_core_ratios; + msr_t platform_info; + unsigned int bclk_khz = cpu_bus_freq_khz(); + + if (!bclk_khz) + return 0; - ia_core_ratios = rdmsr(MSR_IACORE_RATIOS); - return (BUS_FREQ_KHZ * ((ia_core_ratios.lo >> 16) & 0x3f)) / 1000; + platform_info = rdmsr(MSR_PLATFORM_INFO); + return (bclk_khz * ((platform_info.lo >> 8) & 0xff)) / 1000; } #if !ENV_SMM |