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/slab.h>
  17 #include <linux/sched.h>
  18 #include <linux/smp.h>
  19 #include <linux/init.h>
  20 #include <linux/io.h>
  21
  22 #include <mach/hardware.h>
  23 #include <mach/platform.h>
  24 #include <asm/mach-types.h>
  25 #include <asm/hardware/icst525.h>
  26
  27 static struct cpufreq_driver integrator_driver;
  28
  29 #define CM_ID   IO_ADDRESS(INTEGRATOR_HDR_ID)
  30 #define CM_OSC  IO_ADDRESS(INTEGRATOR_HDR_OSC)
  31 #define CM_STAT IO_ADDRESS(INTEGRATOR_HDR_STAT)
  32 #define CM_LOCK IO_ADDRESS(INTEGRATOR_HDR_LOCK)
  33
  34 static const struct icst_params lclk_params = {
  35         .ref            = 24000000,
  36         .vco_max        = ICST525_VCO_MAX_5V,
  37         .vco_min        = ICST525_VCO_MIN,
  38         .vd_min         = 8,
  39         .vd_max         = 132,
  40         .rd_min         = 24,
  41         .rd_max         = 24,
  42         .s2div          = icst525_s2div,
  43         .idx2s          = icst525_idx2s,
  44 };
  45
  46 static const struct icst_params cclk_params = {
  47         .ref            = 24000000,
  48         .vco_max        = ICST525_VCO_MAX_5V,
  49         .vco_min        = ICST525_VCO_MIN,
  50         .vd_min         = 12,
  51         .vd_max         = 160,
  52         .rd_min         = 24,
  53         .rd_max         = 24,
  54         .s2div          = icst525_s2div,
  55         .idx2s          = icst525_idx2s,
  56 };
  57
  58 /*
  59  * Validate the speed policy.
  60  */
  61 static int integrator_verify_policy(struct cpufreq_policy *policy)
  62 {
  63         struct icst_vco vco;
  64
  65         cpufreq_verify_within_limits(policy,
  66                                      policy->cpuinfo.min_freq,
  67                                      policy->cpuinfo.max_freq);
  68
  69         vco = icst525_hz_to_vco(&cclk_params, policy->max * 1000);
  70         policy->max = icst525_hz(&cclk_params, vco) / 1000;
  71
  72         vco = icst525_hz_to_vco(&cclk_params, policy->min * 1000);
  73         policy->min = icst525_hz(&cclk_params, vco) / 1000;
  74
  75         cpufreq_verify_within_limits(policy,
  76                                      policy->cpuinfo.min_freq,
  77                                      policy->cpuinfo.max_freq);
  78
  79         return 0;
  80 }
  81
  82
  83 static int integrator_set_target(struct cpufreq_policy *policy,
  84                                  unsigned int target_freq,
  85                                  unsigned int relation)
  86 {
  87         cpumask_t cpus_allowed;
  88         int cpu = policy->cpu;
  89         struct icst_vco vco;
  90         struct cpufreq_freqs freqs;
  91         u_int cm_osc;
  92
  93         /*
  94          * Save this threads cpus_allowed mask.
  95          */
  96         cpus_allowed = current->cpus_allowed;
  97
  98         /*
  99          * Bind to the specified CPU.  When this call returns,
 100          * we should be running on the right CPU.
 101          */
 102         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 103         BUG_ON(cpu != smp_processor_id());
 104
 105         /* get current setting */
 106         cm_osc = __raw_readl(CM_OSC);
 107
 108         if (machine_is_integrator()) {
 109                 vco.s = (cm_osc >> 8) & 7;
 110         } else if (machine_is_cintegrator()) {
 111                 vco.s = 1;
 112         }
 113         vco.v = cm_osc & 255;
 114         vco.r = 22;
 115         freqs.old = icst525_hz(&cclk_params, vco) / 1000;
 116
 117         /* icst525_hz_to_vco rounds down -- so we need the next
 118          * larger freq in case of CPUFREQ_RELATION_L.
 119          */
 120         if (relation == CPUFREQ_RELATION_L)
 121                 target_freq += 999;
 122         if (target_freq > policy->max)
 123                 target_freq = policy->max;
 124         vco = icst525_hz_to_vco(&cclk_params, target_freq * 1000);
 125         freqs.new = icst525_hz(&cclk_params, vco) / 1000;
 126
 127         freqs.cpu = policy->cpu;
 128
 129         if (freqs.old == freqs.new) {
 130                 set_cpus_allowed(current, cpus_allowed);
 131                 return 0;
 132         }
 133
 134         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
 135
 136         cm_osc = __raw_readl(CM_OSC);
 137
 138         if (machine_is_integrator()) {
 139                 cm_osc &= 0xfffff800;
 140                 cm_osc |= vco.s << 8;
 141         } else if (machine_is_cintegrator()) {
 142                 cm_osc &= 0xffffff00;
 143         }
 144         cm_osc |= vco.v;
 145
 146         __raw_writel(0xa05f, CM_LOCK);
 147         __raw_writel(cm_osc, CM_OSC);
 148         __raw_writel(0, CM_LOCK);
 149
 150         /*
 151          * Restore the CPUs allowed mask.
 152          */
 153         set_cpus_allowed(current, cpus_allowed);
 154
 155         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 156
 157         return 0;
 158 }
 159
 160 static unsigned int integrator_get(unsigned int cpu)
 161 {
 162         cpumask_t cpus_allowed;
 163         unsigned int current_freq;
 164         u_int cm_osc;
 165         struct icst_vco vco;
 166
 167         cpus_allowed = current->cpus_allowed;
 168
 169         set_cpus_allowed(current, cpumask_of_cpu(cpu));
 170         BUG_ON(cpu != smp_processor_id());
 171
 172         /* detect memory etc. */
 173         cm_osc = __raw_readl(CM_OSC);
 174
 175         if (machine_is_integrator()) {
 176                 vco.s = (cm_osc >> 8) & 7;
 177         } else if (machine_is_cintegrator()) {
 178                 vco.s = 1;
 179         }
 180         vco.v = cm_osc & 255;
 181         vco.r = 22;
 182
 183         current_freq = icst525_hz(&cclk_params, vco) / 1000; /* current freq */
 184
 185         set_cpus_allowed(current, cpus_allowed);
 186
 187         return current_freq;
 188 }
 189
 190 static int integrator_cpufreq_init(struct cpufreq_policy *policy)
 191 {
 192
 193         /* set default policy and cpuinfo */
 194         policy->cpuinfo.max_freq = 160000;
 195         policy->cpuinfo.min_freq = 12000;
 196         policy->cpuinfo.transition_latency = 1000000; /* 1 ms, assumed */
 197         policy->cur = policy->min = policy->max = integrator_get(policy->cpu);
 198
 199         return 0;
 200 }
 201
 202 static struct cpufreq_driver integrator_driver = {
 203         .verify         = integrator_verify_policy,
 204         .target         = integrator_set_target,
 205         .get            = integrator_get,
 206         .init           = integrator_cpufreq_init,
 207         .name           = "integrator",
 208 };
 209
 210 static int __init integrator_cpu_init(void)
 211 {
 212         return cpufreq_register_driver(&integrator_driver);
 213 }
 214
 215 static void __exit integrator_cpu_exit(void)
 216 {
 217         cpufreq_unregister_driver(&integrator_driver);
 218 }
 219
 220 MODULE_AUTHOR ("Russell M. King");
 221 MODULE_DESCRIPTION ("cpufreq driver for ARM Integrator CPUs");
 222 MODULE_LICENSE ("GPL");
 223
 224 module_init(integrator_cpu_init);
 225 module_exit(integrator_cpu_exit);