projects / mirror_ubuntu-artful-kernel.git / blame
| 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); |