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gerrit-public.fairphone.software / kernel / msm-4.9 / f8ce25476d5f12ffa29b885e49c38cd95053437e / . / arch / arm / plat-omap / cpu-omap.c
blob: 98edc9fdd6d10df39ee8d360b5108397f78112fe [file] [log] [blame]
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100[diff] [blame]1/*
2 * linux/arch/arm/plat-omap/cpu-omap.c
3 *
4 * CPU frequency scaling for OMAP
5 *
6 * Copyright (C) 2005 Nokia Corporation
7 * Written by Tony Lindgren <tony@atomide.com>
8 *
9 * Based on cpu-sa1110.c, Copyright (C) 2001 Russell King
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/sched.h>
18#include <linux/cpufreq.h>
19#include <linux/delay.h>
20#include <linux/init.h>
21#include <linux/err.h>
Russell Kingf8ce2542006-01-07 16:15:52 +0000[diff] [blame^]22#include <linux/clk.h>
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100[diff] [blame]23
24#include <asm/hardware.h>
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100[diff] [blame]25#include <asm/io.h>
26#include <asm/system.h>
27
Tony Lindgrenec6bced2005-07-10 19:58:20 +0100[diff] [blame]28/* TODO: Add support for SDRAM timing changes */
29
30int omap_verify_speed(struct cpufreq_policy *policy)
31{
32 struct clk * mpu_clk;
33
34 if (policy->cpu)
35 return -EINVAL;
36
37 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
38 policy->cpuinfo.max_freq);
39 mpu_clk = clk_get(NULL, "mpu");
40 if (IS_ERR(mpu_clk))
41 return PTR_ERR(mpu_clk);
42 policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000;
43 policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000;
44 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
45 policy->cpuinfo.max_freq);
46 clk_put(mpu_clk);
47
48 return 0;
49}
50
51unsigned int omap_getspeed(unsigned int cpu)
52{
53 struct clk * mpu_clk;
54 unsigned long rate;
55
56 if (cpu)
57 return 0;
58
59 mpu_clk = clk_get(NULL, "mpu");
60 if (IS_ERR(mpu_clk))
61 return 0;
62 rate = clk_get_rate(mpu_clk) / 1000;
63 clk_put(mpu_clk);
64
65 return rate;
66}
67
68static int omap_target(struct cpufreq_policy *policy,
69 unsigned int target_freq,
70 unsigned int relation)
71{
72 struct clk * mpu_clk;
73 struct cpufreq_freqs freqs;
74 int ret = 0;
75
76 mpu_clk = clk_get(NULL, "mpu");
77 if (IS_ERR(mpu_clk))
78 return PTR_ERR(mpu_clk);
79
80 freqs.old = omap_getspeed(0);
81 freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000;
82 freqs.cpu = 0;
83
84 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
85 ret = clk_set_rate(mpu_clk, target_freq * 1000);
86 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
87 clk_put(mpu_clk);
88
89 return ret;
90}
91
92static int __init omap_cpu_init(struct cpufreq_policy *policy)
93{
94 struct clk * mpu_clk;
95
96 mpu_clk = clk_get(NULL, "mpu");
97 if (IS_ERR(mpu_clk))
98 return PTR_ERR(mpu_clk);
99
100 if (policy->cpu != 0)
101 return -EINVAL;
102 policy->cur = policy->min = policy->max = omap_getspeed(0);
103 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
104 policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000;
105 policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, 216000000) / 1000;
106 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
107 clk_put(mpu_clk);
108
109 return 0;
110}
111
112static struct cpufreq_driver omap_driver = {
113 .flags = CPUFREQ_STICKY,
114 .verify = omap_verify_speed,
115 .target = omap_target,
116 .get = omap_getspeed,
117 .init = omap_cpu_init,
118 .name = "omap",
119};
120
121static int __init omap_cpufreq_init(void)
122{
123 return cpufreq_register_driver(&omap_driver);
124}
125
126arch_initcall(omap_cpufreq_init);