LXR linux/arch/x86/platform/intel-mid/mfld.c

   1/*
   2 * mfld.c: Intel Medfield platform setup code
   3 *
   4 * (C) Copyright 2013 Intel Corporation
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; version 2
   9 * of the License.
  10 */
  11
  12#include <linux/init.h>
  13
  14#include <asm/apic.h>
  15#include <asm/intel-mid.h>
  16#include <asm/intel_mid_vrtc.h>
  17
  18#include "intel_mid_weak_decls.h"
  19
  20static void penwell_arch_setup(void);
  21/* penwell arch ops */
  22static struct intel_mid_ops penwell_ops = {
  23        .arch_setup = penwell_arch_setup,
  24};
  25
  26static void mfld_power_off(void)
  27{
  28}
  29
  30static unsigned long __init mfld_calibrate_tsc(void)
  31{
  32        unsigned long fast_calibrate;
  33        u32 lo, hi, ratio, fsb;
  34
  35        rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
  36        pr_debug("IA32 perf status is 0x%x, 0x%0x\n", lo, hi);
  37        ratio = (hi >> 8) & 0x1f;
  38        pr_debug("ratio is %d\n", ratio);
  39        if (!ratio) {
  40                pr_err("read a zero ratio, should be incorrect!\n");
  41                pr_err("force tsc ratio to 16 ...\n");
  42                ratio = 16;
  43        }
  44        rdmsr(MSR_FSB_FREQ, lo, hi);
  45        if ((lo & 0x7) == 0x7)
  46                fsb = FSB_FREQ_83SKU;
  47        else
  48                fsb = FSB_FREQ_100SKU;
  49        fast_calibrate = ratio * fsb;
  50        pr_debug("read penwell tsc %lu khz\n", fast_calibrate);
  51        lapic_timer_frequency = fsb * 1000 / HZ;
  52        /* mark tsc clocksource as reliable */
  53        set_cpu_cap(&boot_cpu_data, X86_FEATURE_TSC_RELIABLE);
  54
  55        if (fast_calibrate)
  56                return fast_calibrate;
  57
  58        return 0;
  59}
  60
  61static void __init penwell_arch_setup(void)
  62{
  63        x86_platform.calibrate_tsc = mfld_calibrate_tsc;
  64        pm_power_off = mfld_power_off;
  65}
  66
  67void *get_penwell_ops(void)
  68{
  69        return &penwell_ops;
  70}
  71
  72void *get_cloverview_ops(void)
  73{
  74        return &penwell_ops;
  75}
  76