xref: /linux/arch/mips/loongson2ef/lemote-2f/clock.c (revision 02680c23d7b3febe45ea3d4f9818c2b2dc89020a)
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);
52