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gerrit-public.fairphone.software / kernel / msm-4.9 / ec6bced6c7b92904f5ead39c9c1b8dc734e6eff0 / . / arch / arm / plat-omap / cpu-omap.c
blob: 409aac2c4b9de75400cf0f34bc50131362bb7125 [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>
22
23#include <asm/hardware.h>
24#include <asm/mach-types.h>
25#include <asm/io.h>
26#include <asm/system.h>
27
28#include <asm/hardware/clock.h>
29
30/* TODO: Add support for SDRAM timing changes */
31
32int omap_verify_speed(struct cpufreq_policy *policy)
33{
34 struct clk * mpu_clk;
35
36 if (policy->cpu)
37 return -EINVAL;
38
39 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
40 policy->cpuinfo.max_freq);
41 mpu_clk = clk_get(NULL, "mpu");
42 if (IS_ERR(mpu_clk))
43 return PTR_ERR(mpu_clk);
44 policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000;
45 policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000;
46 cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
47 policy->cpuinfo.max_freq);
48 clk_put(mpu_clk);
49
50 return 0;
51}
52
53unsigned int omap_getspeed(unsigned int cpu)
54{
55 struct clk * mpu_clk;
56 unsigned long rate;
57
58 if (cpu)
59 return 0;
60
61 mpu_clk = clk_get(NULL, "mpu");
62 if (IS_ERR(mpu_clk))
63 return 0;
64 rate = clk_get_rate(mpu_clk) / 1000;
65 clk_put(mpu_clk);
66
67 return rate;
68}
69
70static int omap_target(struct cpufreq_policy *policy,
71 unsigned int target_freq,
72 unsigned int relation)
73{
74 struct clk * mpu_clk;
75 struct cpufreq_freqs freqs;
76 int ret = 0;
77
78 mpu_clk = clk_get(NULL, "mpu");
79 if (IS_ERR(mpu_clk))
80 return PTR_ERR(mpu_clk);
81
82 freqs.old = omap_getspeed(0);
83 freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000;
84 freqs.cpu = 0;
85
86 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
87 ret = clk_set_rate(mpu_clk, target_freq * 1000);
88 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
89 clk_put(mpu_clk);
90
91 return ret;
92}
93
94static int __init omap_cpu_init(struct cpufreq_policy *policy)
95{
96 struct clk * mpu_clk;
97
98 mpu_clk = clk_get(NULL, "mpu");
99 if (IS_ERR(mpu_clk))
100 return PTR_ERR(mpu_clk);
101
102 if (policy->cpu != 0)
103 return -EINVAL;
104 policy->cur = policy->min = policy->max = omap_getspeed(0);
105 policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
106 policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000;
107 policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, 216000000) / 1000;
108 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
109 clk_put(mpu_clk);
110
111 return 0;
112}
113
114static struct cpufreq_driver omap_driver = {
115 .flags = CPUFREQ_STICKY,
116 .verify = omap_verify_speed,
117 .target = omap_target,
118 .get = omap_getspeed,
119 .init = omap_cpu_init,
120 .name = "omap",
121};
122
123static int __init omap_cpufreq_init(void)
124{
125 return cpufreq_register_driver(&omap_driver);
126}
127
128arch_initcall(omap_cpufreq_init);