Commit | Line | Data |
---|---|---|
ec6bced6 TL |
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> | |
f8ce2547 | 22 | #include <linux/clk.h> |
ec6bced6 TL |
23 | |
24 | #include <asm/hardware.h> | |
ec6bced6 TL |
25 | #include <asm/io.h> |
26 | #include <asm/system.h> | |
27 | ||
a7ca9d2b TL |
28 | #define VERY_HI_RATE 900000000 |
29 | ||
30 | #ifdef CONFIG_ARCH_OMAP1 | |
31 | #define MPU_CLK "mpu" | |
32 | #else | |
33 | #define MPU_CLK "virt_prcm_set" | |
34 | #endif | |
35 | ||
ec6bced6 TL |
36 | /* TODO: Add support for SDRAM timing changes */ |
37 | ||
38 | int omap_verify_speed(struct cpufreq_policy *policy) | |
39 | { | |
40 | struct clk * mpu_clk; | |
41 | ||
42 | if (policy->cpu) | |
43 | return -EINVAL; | |
44 | ||
45 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, | |
46 | policy->cpuinfo.max_freq); | |
a7ca9d2b | 47 | mpu_clk = clk_get(NULL, MPU_CLK); |
ec6bced6 TL |
48 | if (IS_ERR(mpu_clk)) |
49 | return PTR_ERR(mpu_clk); | |
50 | policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000; | |
51 | policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000; | |
52 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, | |
53 | policy->cpuinfo.max_freq); | |
54 | clk_put(mpu_clk); | |
55 | ||
56 | return 0; | |
57 | } | |
58 | ||
59 | unsigned int omap_getspeed(unsigned int cpu) | |
60 | { | |
61 | struct clk * mpu_clk; | |
62 | unsigned long rate; | |
63 | ||
64 | if (cpu) | |
65 | return 0; | |
66 | ||
a7ca9d2b | 67 | mpu_clk = clk_get(NULL, MPU_CLK); |
ec6bced6 TL |
68 | if (IS_ERR(mpu_clk)) |
69 | return 0; | |
70 | rate = clk_get_rate(mpu_clk) / 1000; | |
71 | clk_put(mpu_clk); | |
72 | ||
73 | return rate; | |
74 | } | |
75 | ||
76 | static int omap_target(struct cpufreq_policy *policy, | |
77 | unsigned int target_freq, | |
78 | unsigned int relation) | |
79 | { | |
80 | struct clk * mpu_clk; | |
81 | struct cpufreq_freqs freqs; | |
82 | int ret = 0; | |
83 | ||
a7ca9d2b | 84 | mpu_clk = clk_get(NULL, MPU_CLK); |
ec6bced6 TL |
85 | if (IS_ERR(mpu_clk)) |
86 | return PTR_ERR(mpu_clk); | |
87 | ||
88 | freqs.old = omap_getspeed(0); | |
89 | freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000; | |
90 | freqs.cpu = 0; | |
91 | ||
92 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
93 | ret = clk_set_rate(mpu_clk, target_freq * 1000); | |
94 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
95 | clk_put(mpu_clk); | |
96 | ||
97 | return ret; | |
98 | } | |
99 | ||
100 | static int __init omap_cpu_init(struct cpufreq_policy *policy) | |
101 | { | |
102 | struct clk * mpu_clk; | |
103 | ||
a7ca9d2b | 104 | mpu_clk = clk_get(NULL, MPU_CLK); |
ec6bced6 TL |
105 | if (IS_ERR(mpu_clk)) |
106 | return PTR_ERR(mpu_clk); | |
107 | ||
108 | if (policy->cpu != 0) | |
109 | return -EINVAL; | |
110 | policy->cur = policy->min = policy->max = omap_getspeed(0); | |
ec6bced6 | 111 | policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000; |
a7ca9d2b | 112 | policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, VERY_HI_RATE) / 1000; |
ec6bced6 TL |
113 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
114 | clk_put(mpu_clk); | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
119 | static struct cpufreq_driver omap_driver = { | |
120 | .flags = CPUFREQ_STICKY, | |
121 | .verify = omap_verify_speed, | |
122 | .target = omap_target, | |
123 | .get = omap_getspeed, | |
124 | .init = omap_cpu_init, | |
125 | .name = "omap", | |
126 | }; | |
127 | ||
128 | static int __init omap_cpufreq_init(void) | |
129 | { | |
130 | return cpufreq_register_driver(&omap_driver); | |
131 | } | |
132 | ||
133 | arch_initcall(omap_cpufreq_init); |