arch/mips/loongson2ef/lemote-2f/clock.c

   1 /*
   2  * Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology
   3  * Author: Yanhua, yanh@lemote.com
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  */
   9 #include <linux/cpufreq.h>
  10 #include <linux/errno.h>
  11 #include <linux/export.h>
  12
  13 #include <asm/mach-loongson2ef/loongson.h>
  14
  15 enum {
  16         DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT,
  17         DC_87PT, DC_DISABLE, DC_RESV
  18 };
  19
  20 struct cpufreq_frequency_table loongson2_clockmod_table[] = {
  21         {0, DC_RESV, CPUFREQ_ENTRY_INVALID},
  22         {0, DC_ZERO, CPUFREQ_ENTRY_INVALID},
  23         {0, DC_25PT, 0},
  24         {0, DC_37PT, 0},
  25         {0, DC_50PT, 0},
  26         {0, DC_62PT, 0},
  27         {0, DC_75PT, 0},
  28         {0, DC_87PT, 0},
  29         {0, DC_DISABLE, 0},
  30         {0, DC_RESV, CPUFREQ_TABLE_END},
  31 };
  32 EXPORT_SYMBOL_GPL(loongson2_clockmod_table);
  33
  34 int loongson2_cpu_set_rate(unsigned long rate_khz)
  35 {
  36         struct cpufreq_frequency_table *pos;
  37         int regval;
  38
  39         cpufreq_for_each_valid_entry(pos, loongson2_clockmod_table)
  40                 if (rate_khz == pos->frequency)
  41                         break;
  42         if (rate_khz != pos->frequency)
  43                 return -ENOTSUPP;
  44
  45         regval = readl(LOONGSON_CHIPCFG);
  46         regval = (regval & ~0x7) | (pos->driver_data - 1);
  47         writel(regval, LOONGSON_CHIPCFG);
  48
  49         return 0;
  50 }
  51 EXPORT_SYMBOL_GPL(loongson2_cpu_set_rate);