1/* 2 * linux/arch/arm/mach-integrator/cpu.c 3 * 4 * Copyright (C) 2001-2002 Deep Blue Solutions Ltd. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 * CPU support functions 11 */ 12#include <linux/module.h> 13#include <linux/types.h> 14#include <linux/kernel.h> 15#include <linux/cpufreq.h> 16#include <linux/sched.h> 17#include <linux/smp.h> 18#include <linux/init.h> 19#include <linux/io.h> 20 21#include <mach/hardware.h> 22#include <mach/platform.h> 23#include <asm/mach-types.h> 24#include <asm/hardware/icst.h> 25 26static struct cpufreq_driver integrator_driver; 27 28#define CM_ID IO_ADDRESS(INTEGRATOR_HDR_ID) 29#define CM_OSC IO_ADDRESS(INTEGRATOR_HDR_OSC) 30#define CM_STAT IO_ADDRESS(INTEGRATOR_HDR_STAT) 31#define CM_LOCK IO_ADDRESS(INTEGRATOR_HDR_LOCK) 32 33static const struct icst_params lclk_params = { 34 .ref = 24000000, 35 .vco_max = ICST525_VCO_MAX_5V, 36 .vco_min = ICST525_VCO_MIN, 37 .vd_min = 8, 38 .vd_max = 132, 39 .rd_min = 24, 40 .rd_max = 24, 41 .s2div = icst525_s2div, 42 .idx2s = icst525_idx2s, 43}; 44 45static const struct icst_params cclk_params = { 46 .ref = 24000000, 47 .vco_max = ICST525_VCO_MAX_5V, 48 .vco_min = ICST525_VCO_MIN, 49 .vd_min = 12, 50 .vd_max = 160, 51 .rd_min = 24, 52 .rd_max = 24, 53 .s2div = icst525_s2div, 54 .idx2s = icst525_idx2s, 55}; 56 57/* 58 * Validate the speed policy. 59 */ 60static int integrator_verify_policy(struct cpufreq_policy *policy) 61{ 62 struct icst_vco vco; 63 64 cpufreq_verify_within_limits(policy, 65 policy->cpuinfo.min_freq, 66 policy->cpuinfo.max_freq); 67 68 vco = icst_hz_to_vco(&cclk_params, policy->max * 1000); 69 policy->max = icst_hz(&cclk_params, vco) / 1000; 70 71 vco = icst_hz_to_vco(&cclk_params, policy->min * 1000); 72 policy->min = icst_hz(&cclk_params, vco) / 1000; 73 74 cpufreq_verify_within_limits(policy, 75 policy->cpuinfo.min_freq, 76 policy->cpuinfo.max_freq); 77 78 return 0; 79} 80 81 82static int integrator_set_target(struct cpufreq_policy *policy, 83 unsigned int target_freq, 84 unsigned int relation) 85{ 86 cpumask_t cpus_allowed; 87 int cpu = policy->cpu; 88 struct icst_vco vco; 89 struct cpufreq_freqs freqs; 90 u_int cm_osc; 91 92 /* 93 * Save this threads cpus_allowed mask. 94 */ 95 cpus_allowed = current->cpus_allowed; 96 97 /* 98 * Bind to the specified CPU. When this call returns, 99 * we should be running on the right CPU. 100 */ 101 set_cpus_allowed(current, cpumask_of_cpu(cpu)); 102 BUG_ON(cpu != smp_processor_id()); 103 104 /* get current setting */ 105 cm_osc = __raw_readl(CM_OSC); 106 107 if (machine_is_integrator()) { 108 vco.s = (cm_osc >> 8) & 7; 109 } else if (machine_is_cintegrator()) { 110 vco.s = 1; 111 } 112 vco.v = cm_osc & 255; 113 vco.r = 22; 114 freqs.old = icst_hz(&cclk_params, vco) / 1000; 115 116 /* icst_hz_to_vco rounds down -- so we need the next 117 * larger freq in case of CPUFREQ_RELATION_L. 118 */ 119 if (relation == CPUFREQ_RELATION_L) 120 target_freq += 999; 121 if (target_freq > policy->max) 122 target_freq = policy->max; 123 vco = icst_hz_to_vco(&cclk_params, target_freq * 1000); 124 freqs.new = icst_hz(&cclk_params, vco) / 1000; 125 126 freqs.cpu = policy->cpu; 127 128 if (freqs.old == freqs.new) { 129 set_cpus_allowed(current, cpus_allowed); 130 return 0; 131 } 132 133 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); 134 135 cm_osc = __raw_readl(CM_OSC); 136 137 if (machine_is_integrator()) { 138 cm_osc &= 0xfffff800; 139 cm_osc |= vco.s << 8; 140 } else if (machine_is_cintegrator()) { 141 cm_osc &= 0xffffff00; 142 } 143 cm_osc |= vco.v; 144 145 __raw_writel(0xa05f, CM_LOCK); 146 __raw_writel(cm_osc, CM_OSC); 147 __raw_writel(0, CM_LOCK); 148 149 /* 150 * Restore the CPUs allowed mask. 151 */ 152 set_cpus_allowed(current, cpus_allowed); 153 154 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); 155 156 return 0; 157} 158 159static unsigned int integrator_get(unsigned int cpu) 160{ 161 cpumask_t cpus_allowed; 162 unsigned int current_freq; 163 u_int cm_osc; 164 struct icst_vco vco; 165 166 cpus_allowed = current->cpus_allowed; 167 168 set_cpus_allowed(current, cpumask_of_cpu(cpu)); 169 BUG_ON(cpu != smp_processor_id()); 170 171 /* detect memory etc. */ 172 cm_osc = __raw_readl(CM_OSC); 173 174 if (machine_is_integrator()) { 175 vco.s = (cm_osc >> 8) & 7; 176 } else if (machine_is_cintegrator()) { 177 vco.s = 1; 178 } 179 vco.v = cm_osc & 255; 180 vco.r = 22; 181 182 current_freq = icst_hz(&cclk_params, vco) / 1000; /* current freq */ 183 184 set_cpus_allowed(current, cpus_allowed); 185 186 return current_freq; 187} 188 189static int integrator_cpufreq_init(struct cpufreq_policy *policy) 190{ 191 192 /* set default policy and cpuinfo */ 193 policy->cpuinfo.max_freq = 160000; 194 policy->cpuinfo.min_freq = 12000; 195 policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */ 196 policy->cur = policy->min = policy->max = integrator_get(policy->cpu); 197 198 return 0; 199} 200 201static struct cpufreq_driver integrator_driver = { 202 .verify = integrator_verify_policy, 203 .target = integrator_set_target, 204 .get = integrator_get, 205 .init = integrator_cpufreq_init, 206 .name = "integrator", 207}; 208 209static int __init integrator_cpu_init(void) 210{ 211 return cpufreq_register_driver(&integrator_driver); 212} 213 214static void __exit integrator_cpu_exit(void) 215{ 216 cpufreq_unregister_driver(&integrator_driver); 217} 218 219MODULE_AUTHOR ("Russell M. King"); 220MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs"); 221MODULE_LICENSE ("GPL"); 222 223module_init(integrator_cpu_init); 224module_exit(integrator_cpu_exit); 225