drivers/cpufreq/integrator-cpufreq.c

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