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kernel/linux-rt-4.4.41/drivers/cpufreq/ppc_cbe_cpufreq_pervasive.c 2.86 KB
5113f6f70   김현기   kernel add
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  /*
   * pervasive backend for the cbe_cpufreq driver
   *
   * This driver makes use of the pervasive unit to
   * engage the desired frequency.
   *
   * (C) Copyright IBM Deutschland Entwicklung GmbH 2005-2007
   *
   * Author: Christian Krafft <krafft@de.ibm.com>
   *
   * 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; either version 2, or (at your option)
   * any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #include <linux/io.h>
  #include <linux/kernel.h>
  #include <linux/time.h>
  #include <asm/machdep.h>
  #include <asm/hw_irq.h>
  #include <asm/cell-regs.h>
  
  #include "ppc_cbe_cpufreq.h"
  
  /* to write to MIC register */
  static u64 MIC_Slow_Fast_Timer_table[] = {
  	[0 ... 7] = 0x007fc00000000000ull,
  };
  
  /* more values for the MIC */
  static u64 MIC_Slow_Next_Timer_table[] = {
  	0x0000240000000000ull,
  	0x0000268000000000ull,
  	0x000029C000000000ull,
  	0x00002D0000000000ull,
  	0x0000300000000000ull,
  	0x0000334000000000ull,
  	0x000039C000000000ull,
  	0x00003FC000000000ull,
  };
  
  
  int cbe_cpufreq_set_pmode(int cpu, unsigned int pmode)
  {
  	struct cbe_pmd_regs __iomem *pmd_regs;
  	struct cbe_mic_tm_regs __iomem *mic_tm_regs;
  	unsigned long flags;
  	u64 value;
  #ifdef DEBUG
  	long time;
  #endif
  
  	local_irq_save(flags);
  
  	mic_tm_regs = cbe_get_cpu_mic_tm_regs(cpu);
  	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
  
  #ifdef DEBUG
  	time = jiffies;
  #endif
  
  	out_be64(&mic_tm_regs->slow_fast_timer_0, MIC_Slow_Fast_Timer_table[pmode]);
  	out_be64(&mic_tm_regs->slow_fast_timer_1, MIC_Slow_Fast_Timer_table[pmode]);
  
  	out_be64(&mic_tm_regs->slow_next_timer_0, MIC_Slow_Next_Timer_table[pmode]);
  	out_be64(&mic_tm_regs->slow_next_timer_1, MIC_Slow_Next_Timer_table[pmode]);
  
  	value = in_be64(&pmd_regs->pmcr);
  	/* set bits to zero */
  	value &= 0xFFFFFFFFFFFFFFF8ull;
  	/* set bits to next pmode */
  	value |= pmode;
  
  	out_be64(&pmd_regs->pmcr, value);
  
  #ifdef DEBUG
  	/* wait until new pmode appears in status register */
  	value = in_be64(&pmd_regs->pmsr) & 0x07;
  	while (value != pmode) {
  		cpu_relax();
  		value = in_be64(&pmd_regs->pmsr) & 0x07;
  	}
  
  	time = jiffies  - time;
  	time = jiffies_to_msecs(time);
  	pr_debug("had to wait %lu ms for a transition using " \
  		 "pervasive unit
  ", time);
  #endif
  	local_irq_restore(flags);
  
  	return 0;
  }
  
  
  int cbe_cpufreq_get_pmode(int cpu)
  {
  	int ret;
  	struct cbe_pmd_regs __iomem *pmd_regs;
  
  	pmd_regs = cbe_get_cpu_pmd_regs(cpu);
  	ret = in_be64(&pmd_regs->pmsr) & 0x07;
  
  	return ret;
  }