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> |
Russell King | fced80c | 2008-09-06 12:10:45 +0100 | [diff] [blame] | 23 | #include <linux/io.h> |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 24 | |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 25 | #include <mach/hardware.h> |
Tony Lindgren | ce491cf | 2009-10-20 09:40:47 -0700 | [diff] [blame] | 26 | #include <plat/clock.h> |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 27 | #include <asm/system.h> |
| 28 | |
Tony Lindgren | a7ca9d2 | 2006-06-26 16:16:17 -0700 | [diff] [blame] | 29 | #define VERY_HI_RATE 900000000 |
| 30 | |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 31 | static struct cpufreq_frequency_table *freq_table; |
| 32 | |
Tony Lindgren | a7ca9d2 | 2006-06-26 16:16:17 -0700 | [diff] [blame] | 33 | #ifdef CONFIG_ARCH_OMAP1 |
| 34 | #define MPU_CLK "mpu" |
| 35 | #else |
| 36 | #define MPU_CLK "virt_prcm_set" |
| 37 | #endif |
| 38 | |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 39 | static struct clk *mpu_clk; |
| 40 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 41 | /* TODO: Add support for SDRAM timing changes */ |
| 42 | |
Manjunath Kondaiah G | b0a330d | 2010-10-08 10:00:19 -0700 | [diff] [blame^] | 43 | static int omap_verify_speed(struct cpufreq_policy *policy) |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 44 | { |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 45 | if (freq_table) |
| 46 | return cpufreq_frequency_table_verify(policy, freq_table); |
| 47 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 48 | if (policy->cpu) |
| 49 | return -EINVAL; |
| 50 | |
| 51 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, |
| 52 | policy->cpuinfo.max_freq); |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 53 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 54 | policy->min = clk_round_rate(mpu_clk, policy->min * 1000) / 1000; |
| 55 | policy->max = clk_round_rate(mpu_clk, policy->max * 1000) / 1000; |
| 56 | cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq, |
| 57 | policy->cpuinfo.max_freq); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 58 | return 0; |
| 59 | } |
| 60 | |
Manjunath Kondaiah G | b0a330d | 2010-10-08 10:00:19 -0700 | [diff] [blame^] | 61 | static unsigned int omap_getspeed(unsigned int cpu) |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 62 | { |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 63 | unsigned long rate; |
| 64 | |
| 65 | if (cpu) |
| 66 | return 0; |
| 67 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 68 | rate = clk_get_rate(mpu_clk) / 1000; |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 69 | return rate; |
| 70 | } |
| 71 | |
| 72 | static int omap_target(struct cpufreq_policy *policy, |
| 73 | unsigned int target_freq, |
| 74 | unsigned int relation) |
| 75 | { |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 76 | struct cpufreq_freqs freqs; |
| 77 | int ret = 0; |
| 78 | |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 79 | /* Ensure desired rate is within allowed range. Some govenors |
| 80 | * (ondemand) will just pass target_freq=0 to get the minimum. */ |
Eero Nurkkala | 60c45ae | 2009-06-23 12:53:29 +0300 | [diff] [blame] | 81 | if (target_freq < policy->min) |
| 82 | target_freq = policy->min; |
| 83 | if (target_freq > policy->max) |
| 84 | target_freq = policy->max; |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 85 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 86 | freqs.old = omap_getspeed(0); |
| 87 | freqs.new = clk_round_rate(mpu_clk, target_freq * 1000) / 1000; |
| 88 | freqs.cpu = 0; |
| 89 | |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 90 | if (freqs.old == freqs.new) |
| 91 | return ret; |
| 92 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 93 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 94 | #ifdef CONFIG_CPU_FREQ_DEBUG |
| 95 | printk(KERN_DEBUG "cpufreq-omap: transition: %u --> %u\n", |
| 96 | freqs.old, freqs.new); |
| 97 | #endif |
| 98 | ret = clk_set_rate(mpu_clk, freqs.new * 1000); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 99 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 100 | |
| 101 | return ret; |
| 102 | } |
| 103 | |
| 104 | static int __init omap_cpu_init(struct cpufreq_policy *policy) |
| 105 | { |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 106 | int result = 0; |
| 107 | |
Tony Lindgren | a7ca9d2 | 2006-06-26 16:16:17 -0700 | [diff] [blame] | 108 | mpu_clk = clk_get(NULL, MPU_CLK); |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 109 | if (IS_ERR(mpu_clk)) |
| 110 | return PTR_ERR(mpu_clk); |
| 111 | |
| 112 | if (policy->cpu != 0) |
| 113 | return -EINVAL; |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 114 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 115 | policy->cur = policy->min = policy->max = omap_getspeed(0); |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 116 | |
| 117 | clk_init_cpufreq_table(&freq_table); |
| 118 | if (freq_table) { |
| 119 | result = cpufreq_frequency_table_cpuinfo(policy, freq_table); |
| 120 | if (!result) |
| 121 | cpufreq_frequency_table_get_attr(freq_table, |
| 122 | policy->cpu); |
| 123 | } else { |
| 124 | policy->cpuinfo.min_freq = clk_round_rate(mpu_clk, 0) / 1000; |
| 125 | policy->cpuinfo.max_freq = clk_round_rate(mpu_clk, |
| 126 | VERY_HI_RATE) / 1000; |
| 127 | } |
| 128 | |
| 129 | /* FIXME: what's the actual transition time? */ |
Mike Turquette | b029839 | 2009-11-11 11:00:38 -0800 | [diff] [blame] | 130 | policy->cpuinfo.transition_latency = 300 * 1000; |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 131 | |
| 132 | return 0; |
| 133 | } |
| 134 | |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 135 | static int omap_cpu_exit(struct cpufreq_policy *policy) |
| 136 | { |
Paul Walmsley | 4e37c10 | 2010-01-08 15:23:16 -0700 | [diff] [blame] | 137 | clk_exit_cpufreq_table(&freq_table); |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 138 | clk_put(mpu_clk); |
| 139 | return 0; |
| 140 | } |
| 141 | |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 142 | static struct freq_attr *omap_cpufreq_attr[] = { |
| 143 | &cpufreq_freq_attr_scaling_available_freqs, |
| 144 | NULL, |
| 145 | }; |
| 146 | |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 147 | static struct cpufreq_driver omap_driver = { |
| 148 | .flags = CPUFREQ_STICKY, |
| 149 | .verify = omap_verify_speed, |
| 150 | .target = omap_target, |
| 151 | .get = omap_getspeed, |
| 152 | .init = omap_cpu_init, |
Hiroshi DOYU | b8488fb | 2007-08-30 12:46:39 +0300 | [diff] [blame] | 153 | .exit = omap_cpu_exit, |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 154 | .name = "omap", |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 155 | .attr = omap_cpufreq_attr, |
Tony Lindgren | ec6bced | 2005-07-10 19:58:20 +0100 | [diff] [blame] | 156 | }; |
| 157 | |
| 158 | static int __init omap_cpufreq_init(void) |
| 159 | { |
| 160 | return cpufreq_register_driver(&omap_driver); |
| 161 | } |
| 162 | |
| 163 | arch_initcall(omap_cpufreq_init); |
Kevin Hilman | aeec299 | 2009-01-27 19:13:38 -0700 | [diff] [blame] | 164 | |
| 165 | /* |
| 166 | * if ever we want to remove this, upon cleanup call: |
| 167 | * |
| 168 | * cpufreq_unregister_driver() |
| 169 | * cpufreq_frequency_table_put_attr() |
| 170 | */ |
| 171 | |