loongson2ef/lemote-2f/clock.c

0001 /*
0002  * Copyright (C) 2006 - 2008 Lemote Inc. & Institute of Computing Technology
0003  * Author: Yanhua, yanh@lemote.com
0004  *
0005  * This file is subject to the terms and conditions of the GNU General Public
0006  * License.  See the file "COPYING" in the main directory of this archive
0007  * for more details.
0008  */
0009 #include <linux/cpufreq.h>
0010 #include <linux/errno.h>
0011 #include <linux/export.h>
0012
0013 #include <asm/mach-loongson2ef/loongson.h>
0014
0015 enum {
0016     DC_ZERO, DC_25PT = 2, DC_37PT, DC_50PT, DC_62PT, DC_75PT,
0017     DC_87PT, DC_DISABLE, DC_RESV
0018 };
0019
0020 struct cpufreq_frequency_table loongson2_clockmod_table[] = {
0021     {0, DC_RESV, CPUFREQ_ENTRY_INVALID},
0022     {0, DC_ZERO, CPUFREQ_ENTRY_INVALID},
0023     {0, DC_25PT, 0},
0024     {0, DC_37PT, 0},
0025     {0, DC_50PT, 0},
0026     {0, DC_62PT, 0},
0027     {0, DC_75PT, 0},
0028     {0, DC_87PT, 0},
0029     {0, DC_DISABLE, 0},
0030     {0, DC_RESV, CPUFREQ_TABLE_END},
0031 };
0032 EXPORT_SYMBOL_GPL(loongson2_clockmod_table);
0033
0034 int loongson2_cpu_set_rate(unsigned long rate_khz)
0035 {
0036     struct cpufreq_frequency_table *pos;
0037     int regval;
0038
0039     cpufreq_for_each_valid_entry(pos, loongson2_clockmod_table)
0040         if (rate_khz == pos->frequency)
0041             break;
0042     if (rate_khz != pos->frequency)
0043         return -ENOTSUPP;
0044
0045     regval = readl(LOONGSON_CHIPCFG);
0046     regval = (regval & ~0x7) | (pos->driver_data - 1);
0047     writel(regval, LOONGSON_CHIPCFG);
0048
0049     return 0;
0050 }
0051 EXPORT_SYMBOL_GPL(loongson2_cpu_set_rate);