release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/mach-integrator/cpu.c

   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
  26 static 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
  33 static 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
  45 static 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  */
  60 static 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
  82 static 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
 159 static 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
 189 static 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
 201 static 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
 209 static int __init integrator_cpu_init(void)
 210 {
 211         return cpufreq_register_driver(&integrator_driver);
 212 }
 213
 214 static void __exit integrator_cpu_exit(void)
 215 {
 216         cpufreq_unregister_driver(&integrator_driver);
 217 }
 218
 219 MODULE_AUTHOR ("Russell M. King");
 220 MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
 221 MODULE_LICENSE ("GPL");
 222
 223 module_init(integrator_cpu_init);
 224 module_exit(integrator_cpu_exit);