Tony Lindgren | ec6bced | 2005-07-10 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 King | f8ce254 | 2006-01-07 16:15:52 +0000 | [diff] [blame] | 22 | #include <linux/clk.h> |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 23 | |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 24 | #include <mach/hardware.h> |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 25 | #include <asm/io.h> |
| 26 | #include <asm/system.h> |
| 27 | |
Tony Lindgren | a7ca9d2 | 2006-06-26 16:16:17 -0700 | [diff] [blame] | 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 | |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 36 | static struct clk *mpu_clk; |
| 37 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 38 | /* TODO: Add support for SDRAM timing changes */ |
| 39 | |
| 40 | int omap_verify_speed(struct cpufreq_policy *policy) |
| 41 | { |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 42 | if (policy->cpu) |
| 43 | return -EINVAL; |
| 44 | |
| 45 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, |
| 46 | policy->cpuinfo.max_freq); |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 47 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 48 | policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000; |
| 49 | policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000; |
| 50 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, |
| 51 | policy->cpuinfo.max_freq); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 52 | return 0; |
| 53 | } |
| 54 | |
| 55 | unsigned int omap_getspeed(unsigned int cpu) |
| 56 | { |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 57 | unsigned long rate; |
| 58 | |
| 59 | if (cpu) |
| 60 | return 0; |
| 61 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 62 | rate = clk_get_rate(mpu_clk) / 1000; |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 63 | return rate; |
| 64 | } |
| 65 | |
| 66 | static int omap_target(struct cpufreq_policy *policy, |
| 67 | unsigned int target_freq, |
| 68 | unsigned int relation) |
| 69 | { |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 70 | struct cpufreq_freqs freqs; |
| 71 | int ret = 0; |
| 72 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 73 | freqs.old = omap_getspeed(0); |
| 74 | freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000; |
| 75 | freqs.cpu = 0; |
| 76 | |
| 77 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
| 78 | ret = clk_set_rate(mpu_clk, target_freq * 1000); |
| 79 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 80 | |
| 81 | return ret; |
| 82 | } |
| 83 | |
| 84 | static int __init omap_cpu_init(struct cpufreq_policy *policy) |
| 85 | { |
Tony Lindgren | a7ca9d2 | 2006-06-26 16:16:17 -0700 | [diff] [blame] | 86 | mpu_clk = clk_get(NULL, MPU_CLK); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 87 | if (IS_ERR(mpu_clk)) |
| 88 | return PTR_ERR(mpu_clk); |
| 89 | |
| 90 | if (policy->cpu != 0) |
| 91 | return -EINVAL; |
| 92 | policy->cur = policy->min = policy->max = omap_getspeed(0); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 93 | policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000; |
Tony Lindgren | a7ca9d2 | 2006-06-26 16:16:17 -0700 | [diff] [blame] | 94 | policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, VERY_HI_RATE) / 1000; |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 95 | policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 96 | |
| 97 | return 0; |
| 98 | } |
| 99 | |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 100 | static int omap_cpu_exit(struct cpufreq_policy *policy) |
| 101 | { |
| 102 | clk_put(mpu_clk); |
| 103 | return 0; |
| 104 | } |
| 105 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 106 | static struct cpufreq_driver omap_driver = { |
| 107 | .flags = CPUFREQ_STICKY, |
| 108 | .verify = omap_verify_speed, |
| 109 | .target = omap_target, |
| 110 | .get = omap_getspeed, |
| 111 | .init = omap_cpu_init, |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 112 | .exit = omap_cpu_exit, |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 113 | .name = "omap", |
| 114 | }; |
| 115 | |
| 116 | static int __init omap_cpufreq_init(void) |
| 117 | { |
| 118 | return cpufreq_register_driver(&omap_driver); |
| 119 | } |
| 120 | |
| 121 | arch_initcall(omap_cpufreq_init); |