diff options
Diffstat (limited to 'arch/x86/platform/intel-mid/mrfld.c')
| -rw-r--r-- | arch/x86/platform/intel-mid/mrfld.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/x86/platform/intel-mid/mrfld.c b/arch/x86/platform/intel-mid/mrfld.c new file mode 100644 index 000000000000..59253db41bbc --- /dev/null +++ b/arch/x86/platform/intel-mid/mrfld.c @@ -0,0 +1,100 @@ +/* + * Intel Merrifield platform specific setup code + * + * (C) Copyright 2013 Intel Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include <linux/init.h> + +#include <asm/apic.h> +#include <asm/intel-mid.h> + +#include "intel_mid_weak_decls.h" + +static unsigned long __init tangier_calibrate_tsc(void) +{ + unsigned long fast_calibrate; + u32 lo, hi, ratio, fsb, bus_freq; + + /* *********************** */ + /* Compute TSC:Ratio * FSB */ + /* *********************** */ + + /* Compute Ratio */ + rdmsr(MSR_PLATFORM_INFO, lo, hi); + pr_debug("IA32 PLATFORM_INFO is 0x%x : %x\n", hi, lo); + + ratio = (lo >> 8) & 0xFF; + pr_debug("ratio is %d\n", ratio); + if (!ratio) { + pr_err("Read a zero ratio, force tsc ratio to 4 ...\n"); + ratio = 4; + } + + /* Compute FSB */ + rdmsr(MSR_FSB_FREQ, lo, hi); + pr_debug("Actual FSB frequency detected by SOC 0x%x : %x\n", + hi, lo); + + bus_freq = lo & 0x7; + pr_debug("bus_freq = 0x%x\n", bus_freq); + + if (bus_freq == 0) + fsb = FSB_FREQ_100SKU; + else if (bus_freq == 1) + fsb = FSB_FREQ_100SKU; + else if (bus_freq == 2) + fsb = FSB_FREQ_133SKU; + else if (bus_freq == 3) + fsb = FSB_FREQ_167SKU; + else if (bus_freq == 4) + fsb = FSB_FREQ_83SKU; + else if (bus_freq == 5) + fsb = FSB_FREQ_400SKU; + else if (bus_freq == 6) + fsb = FSB_FREQ_267SKU; + else if (bus_freq == 7) + fsb = FSB_FREQ_333SKU; + else { + BUG(); + pr_err("Invalid bus_freq! Setting to minimal value!\n"); + fsb = FSB_FREQ_100SKU; + } + + /* TSC = FSB Freq * Resolved HFM Ratio */ + fast_calibrate = ratio * fsb; + pr_debug("calculate tangier tsc %lu KHz\n", fast_calibrate); + + /* ************************************ */ + /* Calculate Local APIC Timer Frequency */ + /* ************************************ */ + lapic_timer_frequency = (fsb * 1000) / HZ; + + pr_debug("Setting lapic_timer_frequency = %d\n", + lapic_timer_frequency); + + /* mark tsc clocksource as reliable */ + set_cpu_cap(&boot_cpu_data, X86_FEATURE_TSC_RELIABLE); + + return fast_calibrate; +} + +static void __init tangier_arch_setup(void) +{ + x86_platform.calibrate_tsc = tangier_calibrate_tsc; +} + +/* tangier arch ops */ +static struct intel_mid_ops tangier_ops = { + .arch_setup = tangier_arch_setup, +}; + +void *get_tangier_ops(void) +{ + return &tangier_ops; +} |