| /* |
| * mrfl.c: 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; |
| } |