LXR linux/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
  15enum {
  16        DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT,
  17        DC_87PT, DC_DISABLE, DC_RESV
  18};
  19
  20struct 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};
  32EXPORT_SYMBOL_GPL(loongson2_clockmod_table);
  33
  34int 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}
  51EXPORT_SYMBOL_GPL(loongson2_cpu_set_rate);
  52