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kernel/linux-rt-4.4.41/arch/x86/platform/intel-mid/mfld.c 1.63 KB
5113f6f70   김현기   kernel add
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  /*
   * mfld.c: Intel Medfield platform 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 <asm/intel_mid_vrtc.h>
  
  #include "intel_mid_weak_decls.h"
  
  static void penwell_arch_setup(void);
  /* penwell arch ops */
  static struct intel_mid_ops penwell_ops = {
  	.arch_setup = penwell_arch_setup,
  };
  
  static void mfld_power_off(void)
  {
  }
  
  static unsigned long __init mfld_calibrate_tsc(void)
  {
  	unsigned long fast_calibrate;
  	u32 lo, hi, ratio, fsb;
  
  	rdmsr(MSR_IA32_PERF_STATUS, lo, hi);
  	pr_debug("IA32 perf status is 0x%x, 0x%0x
  ", lo, hi);
  	ratio = (hi >> 8) & 0x1f;
  	pr_debug("ratio is %d
  ", ratio);
  	if (!ratio) {
  		pr_err("read a zero ratio, should be incorrect!
  ");
  		pr_err("force tsc ratio to 16 ...
  ");
  		ratio = 16;
  	}
  	rdmsr(MSR_FSB_FREQ, lo, hi);
  	if ((lo & 0x7) == 0x7)
  		fsb = FSB_FREQ_83SKU;
  	else
  		fsb = FSB_FREQ_100SKU;
  	fast_calibrate = ratio * fsb;
  	pr_debug("read penwell tsc %lu khz
  ", fast_calibrate);
  	lapic_timer_frequency = fsb * 1000 / HZ;
  	/* mark tsc clocksource as reliable */
  	set_cpu_cap(&boot_cpu_data, X86_FEATURE_TSC_RELIABLE);
  
  	if (fast_calibrate)
  		return fast_calibrate;
  
  	return 0;
  }
  
  static void __init penwell_arch_setup(void)
  {
  	x86_platform.calibrate_tsc = mfld_calibrate_tsc;
  	pm_power_off = mfld_power_off;
  }
  
  void *get_penwell_ops(void)
  {
  	return &penwell_ops;
  }
  
  void *get_cloverview_ops(void)
  {
  	return &penwell_ops;
  }