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 <asm/mach-types.h>
  23 #include <asm/hardware/icst525.h>
  24
  25 static struct cpufreq_driver integrator_driver;
  26
  27 #define CM_ID   (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_ID_OFFSET)
  28 #define CM_OSC  (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_OSC_OFFSET)
  29 #define CM_STAT (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_STAT_OFFSET)
  30 #define CM_LOCK (IO_ADDRESS(INTEGRATOR_HDR_BASE)+INTEGRATOR_HDR_LOCK_OFFSET)
  31
  32 static const struct icst525_params lclk_params = {
  33         .ref            = 24000,
  34         .vco_max        = 320000,
  35         .vd_min         = 8,
  36         .vd_max         = 132,
  37         .rd_min         = 24,
  38         .rd_max         = 24,
  39 };
  40
  41 static const struct icst525_params cclk_params = {
  42         .ref            = 24000,
  43         .vco_max        = 320000,
  44         .vd_min         = 12,
  45         .vd_max         = 160,
  46         .rd_min         = 24,
  47         .rd_max         = 24,
  48 };
  49
  50 /*
  51  * Validate the speed policy.
  52  */
  53 static int integrator_verify_policy(struct cpufreq_policy *policy)
  54 {
  55         struct icst525_vco vco;
  56
  57         cpufreq_verify_within_limits(policy,
  58                                      policy->cpuinfo.min_freq,
  59                                      policy->cpuinfo.max_freq);
  60
  61         vco = icst525_khz_to_vco(&cclk_params, policy->max);
  62         policy->max = icst525_khz(&cclk_params, vco);
  63
  64         vco = icst525_khz_to_vco(&cclk_params, policy->min);
  65         policy->min = icst525_khz(&cclk_params, vco);
  66
  67         cpufreq_verify_within_limits(policy,
  68                                      policy->cpuinfo.min_freq,
  69                                      policy->cpuinfo.max_freq);
  70
  71         return 0;
  72 }
  73
  74
  75 static int integrator_set_target(struct cpufreq_policy *policy,
  76                                  unsigned int target_freq,
  77                                  unsigned int relation)
  78 {
  79         cpumask_t cpus_allowed;
  80         int cpu = policy->cpu;
  81         struct icst525_vco vco;
  82         struct cpufreq_freqs freqs;
  83         u_int cm_osc;
  84
  85         /*
  86          * Save this threads cpus_allowed mask.
  87          */
  88         cpus_allowed = current->cpus_allowed;
  89
  90         /*
  91          * Bind to the specified CPU.  When this call returns,
  92          * we should be running on the right CPU.
  93          */
  94         set_cpus_allowed(current, cpumask_of_cpu(cpu));
  95         BUG_ON(cpu != smp_processor_id());
  96
  97         /* get current setting */
  98         cm_osc = __raw_readl(CM_OSC);
  99
 100         if (machine_is_integrator()) {
 101                 vco.s = (cm_osc >> 8) & 7;
 102         } else if (machine_is_cintegrator()) {
 103                 vco.s = 1;
 104         }
 105         vco.v = cm_osc & 255;
 106         vco.r = 22;
 107         freqs.old = icst525_khz(&cclk_params, vco);
 108
 109         /* icst525_khz_to_vco rounds down -- so we need the next
 110          * larger freq in case of CPUFREQ_RELATION_L.
 111          */
 112         if (relation == CPUFREQ_RELATION_L)
 113                 target_freq += 999;
 114         if (target_freq > policy->max)
 115                 target_freq = policy->max;
 116         vco = icst525_khz_to_vco(&cclk_params, target_freq);
 117         freqs.new = icst525_khz(&cclk_params, vco);
 118
 119         freqs.cpu = policy->cpu;
 120
 121         if (freqs.old == freqs.new) {
 122                 set_cpus_allowed(current, cpus_allowed);
 123                 return 0;
 124         }
 125
 126         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 127
 128         cm_osc = __raw_readl(CM_OSC);
 129
 130         if (machine_is_integrator()) {
 131                 cm_osc &= 0xfffff800;
 132                 cm_osc |= vco.s << 8;
 133         } else if (machine_is_cintegrator()) {
 134                 cm_osc &= 0xffffff00;
 135         }
 136         cm_osc |= vco.v;
 137
 138         __raw_writel(0xa05f, CM_LOCK);
 139         __raw_writel(cm_osc, CM_OSC);
 140         __raw_writel(0, CM_LOCK);
 141
 142         /*
 143          * Restore the CPUs allowed mask.
 144          */
 145         set_cpus_allowed(current, cpus_allowed);
 146
 147         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 148
 149         return 0;
 150 }
 151
 152 static unsigned int integrator_get(unsigned int cpu)
 153 {
 154         cpumask_t cpus_allowed;
 155         unsigned int current_freq;
 156         u_int cm_osc;
 157         struct icst525_vco vco;
 158
 159         cpus_allowed = current->cpus_allowed;
 160
 161         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 162         BUG_ON(cpu != smp_processor_id());
 163
 164         /* detect memory etc. */
 165         cm_osc = __raw_readl(CM_OSC);
 166
 167         if (machine_is_integrator()) {
 168                 vco.s = (cm_osc >> 8) & 7;
 169         } else if (machine_is_cintegrator()) {
 170                 vco.s = 1;
 171         }
 172         vco.v = cm_osc & 255;
 173         vco.r = 22;
 174
 175         current_freq = icst525_khz(&cclk_params, vco); /* current freq */
 176
 177         set_cpus_allowed(current, cpus_allowed);
 178
 179         return current_freq;
 180 }
 181
 182 static int integrator_cpufreq_init(struct cpufreq_policy *policy)
 183 {
 184
 185         /* set default policy and cpuinfo */
 186         policy->cpuinfo.max_freq = 160000;
 187         policy->cpuinfo.min_freq = 12000;
 188         policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */
 189         policy->cur = policy->min = policy->max = integrator_get(policy->cpu);
 190
 191         return 0;
 192 }
 193
 194 static struct cpufreq_driver integrator_driver = {
 195         .verify         = integrator_verify_policy,
 196         .target         = integrator_set_target,
 197         .get            = integrator_get,
 198         .init           = integrator_cpufreq_init,
 199         .name           = "integrator",
 200 };
 201
 202 static int __init integrator_cpu_init(void)
 203 {
 204         return cpufreq_register_driver(&integrator_driver);
 205 }
 206
 207 static void __exit integrator_cpu_exit(void)
 208 {
 209         cpufreq_unregister_driver(&integrator_driver);
 210 }
 211
 212 MODULE_AUTHOR ("Russell M. King");
 213 MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
 214 MODULE_LICENSE ("GPL");
 215
 216 module_init(integrator_cpu_init);
 217 module_exit(integrator_cpu_exit);