arch/arm/mach-omap2/cpuidle44xx.c

   1 /*
   2  * OMAP4+ CPU idle Routines
   3  *
   4  * Copyright (C) 2011-2013 Texas Instruments, Inc.
   5  * Santosh Shilimkar <santosh.shilimkar@ti.com>
   6  * Rajendra Nayak <rnayak@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/sched.h>
  14 #include <linux/cpuidle.h>
  15 #include <linux/cpu_pm.h>
  16 #include <linux/export.h>
  17 #include <linux/tick.h>
  18
  19 #include <asm/cpuidle.h>
  20
  21 #include "common.h"
  22 #include "pm.h"
  23 #include "prm.h"
  24 #include "soc.h"
  25 #include "clockdomain.h"
  26
  27 #define MAX_CPUS        2
  28
  29 /* Machine specific information */
  30 struct idle_statedata {
  31         u32 cpu_state;
  32         u32 mpu_logic_state;
  33         u32 mpu_state;
  34         u32 mpu_state_vote;
  35 };
  36
  37 static struct idle_statedata omap4_idle_data[] = {
  38         {
  39                 .cpu_state = PWRDM_POWER_ON,
  40                 .mpu_state = PWRDM_POWER_ON,
  41                 .mpu_logic_state = PWRDM_POWER_RET,
  42         },
  43         {
  44                 .cpu_state = PWRDM_POWER_OFF,
  45                 .mpu_state = PWRDM_POWER_RET,
  46                 .mpu_logic_state = PWRDM_POWER_RET,
  47         },
  48         {
  49                 .cpu_state = PWRDM_POWER_OFF,
  50                 .mpu_state = PWRDM_POWER_RET,
  51                 .mpu_logic_state = PWRDM_POWER_OFF,
  52         },
  53 };
  54
  55 static struct idle_statedata omap5_idle_data[] = {
  56         {
  57                 .cpu_state = PWRDM_POWER_ON,
  58                 .mpu_state = PWRDM_POWER_ON,
  59                 .mpu_logic_state = PWRDM_POWER_ON,
  60         },
  61         {
  62                 .cpu_state = PWRDM_POWER_RET,
  63                 .mpu_state = PWRDM_POWER_RET,
  64                 .mpu_logic_state = PWRDM_POWER_RET,
  65         },
  66 };
  67
  68 static struct powerdomain *mpu_pd, *cpu_pd[MAX_CPUS];
  69 static struct clockdomain *cpu_clkdm[MAX_CPUS];
  70
  71 static atomic_t abort_barrier;
  72 static bool cpu_done[MAX_CPUS];
  73 static struct idle_statedata *state_ptr = &omap4_idle_data[0];
  74 static DEFINE_RAW_SPINLOCK(mpu_lock);
  75
  76 /* Private functions */
  77
  78 /**
  79  * omap_enter_idle_[simple/coupled] - OMAP4PLUS cpuidle entry functions
  80  * @dev: cpuidle device
  81  * @drv: cpuidle driver
  82  * @index: the index of state to be entered
  83  *
  84  * Called from the CPUidle framework to program the device to the
  85  * specified low power state selected by the governor.
  86  * Returns the amount of time spent in the low power state.
  87  */
  88 static int omap_enter_idle_simple(struct cpuidle_device *dev,
  89                         struct cpuidle_driver *drv,
  90                         int index)
  91 {
  92         omap_do_wfi();
  93         return index;
  94 }
  95
  96 static int omap_enter_idle_smp(struct cpuidle_device *dev,
  97                                struct cpuidle_driver *drv,
  98                                int index)
  99 {
 100         struct idle_statedata *cx = state_ptr + index;
 101         unsigned long flag;
 102
 103         raw_spin_lock_irqsave(&mpu_lock, flag);
 104         cx->mpu_state_vote++;
 105         if (cx->mpu_state_vote == num_online_cpus()) {
 106                 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
 107                 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 108         }
 109         raw_spin_unlock_irqrestore(&mpu_lock, flag);
 110
 111         omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 112
 113         raw_spin_lock_irqsave(&mpu_lock, flag);
 114         if (cx->mpu_state_vote == num_online_cpus())
 115                 omap_set_pwrdm_state(mpu_pd, PWRDM_POWER_ON);
 116         cx->mpu_state_vote--;
 117         raw_spin_unlock_irqrestore(&mpu_lock, flag);
 118
 119         return index;
 120 }
 121
 122 static int omap_enter_idle_coupled(struct cpuidle_device *dev,
 123                         struct cpuidle_driver *drv,
 124                         int index)
 125 {
 126         struct idle_statedata *cx = state_ptr + index;
 127         u32 mpuss_can_lose_context = 0;
 128
 129         /*
 130          * CPU0 has to wait and stay ON until CPU1 is OFF state.
 131          * This is necessary to honour hardware recommondation
 132          * of triggeing all the possible low power modes once CPU1 is
 133          * out of coherency and in OFF mode.
 134          */
 135         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
 136                 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
 137                         cpu_relax();
 138
 139                         /*
 140                          * CPU1 could have already entered & exited idle
 141                          * without hitting off because of a wakeup
 142                          * or a failed attempt to hit off mode.  Check for
 143                          * that here, otherwise we could spin forever
 144                          * waiting for CPU1 off.
 145                          */
 146                         if (cpu_done[1])
 147                             goto fail;
 148
 149                 }
 150         }
 151
 152         mpuss_can_lose_context = (cx->mpu_state == PWRDM_POWER_RET) &&
 153                                  (cx->mpu_logic_state == PWRDM_POWER_OFF);
 154
 155         /* Enter broadcast mode for periodic timers */
 156         tick_broadcast_enable();
 157
 158         /* Enter broadcast mode for one-shot timers */
 159         tick_broadcast_enter();
 160
 161         /*
 162          * Call idle CPU PM enter notifier chain so that
 163          * VFP and per CPU interrupt context is saved.
 164          */
 165         cpu_pm_enter();
 166
 167         if (dev->cpu == 0) {
 168                 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
 169                 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 170
 171                 /*
 172                  * Call idle CPU cluster PM enter notifier chain
 173                  * to save GIC and wakeupgen context.
 174                  */
 175                 if (mpuss_can_lose_context)
 176                         cpu_cluster_pm_enter();
 177         }
 178
 179         omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 180         cpu_done[dev->cpu] = true;
 181
 182         /* Wakeup CPU1 only if it is not offlined */
 183         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
 184
 185                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
 186                     mpuss_can_lose_context)
 187                         gic_dist_disable();
 188
 189                 clkdm_deny_idle(cpu_clkdm[1]);
 190                 omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON);
 191                 clkdm_allow_idle(cpu_clkdm[1]);
 192
 193                 if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD) &&
 194                     mpuss_can_lose_context) {
 195                         while (gic_dist_disabled()) {
 196                                 udelay(1);
 197                                 cpu_relax();
 198                         }
 199                         gic_timer_retrigger();
 200                 }
 201         }
 202
 203         /*
 204          * Call idle CPU PM exit notifier chain to restore
 205          * VFP and per CPU IRQ context.
 206          */
 207         cpu_pm_exit();
 208
 209         /*
 210          * Call idle CPU cluster PM exit notifier chain
 211          * to restore GIC and wakeupgen context.
 212          */
 213         if (dev->cpu == 0 && mpuss_can_lose_context)
 214                 cpu_cluster_pm_exit();
 215
 216         tick_broadcast_exit();
 217
 218 fail:
 219         cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
 220         cpu_done[dev->cpu] = false;
 221
 222         return index;
 223 }
 224
 225 static struct cpuidle_driver omap4_idle_driver = {
 226         .name                           = "omap4_idle",
 227         .owner                          = THIS_MODULE,
 228         .states = {
 229                 {
 230                         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
 231                         .exit_latency = 2 + 2,
 232                         .target_residency = 5,
 233                         .enter = omap_enter_idle_simple,
 234                         .name = "C1",
 235                         .desc = "CPUx ON, MPUSS ON"
 236                 },
 237                 {
 238                         /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 239                         .exit_latency = 328 + 440,
 240                         .target_residency = 960,
 241                         .flags = CPUIDLE_FLAG_COUPLED,
 242                         .enter = omap_enter_idle_coupled,
 243                         .name = "C2",
 244                         .desc = "CPUx OFF, MPUSS CSWR",
 245                 },
 246                 {
 247                         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
 248                         .exit_latency = 460 + 518,
 249                         .target_residency = 1100,
 250                         .flags = CPUIDLE_FLAG_COUPLED,
 251                         .enter = omap_enter_idle_coupled,
 252                         .name = "C3",
 253                         .desc = "CPUx OFF, MPUSS OSWR",
 254                 },
 255         },
 256         .state_count = ARRAY_SIZE(omap4_idle_data),
 257         .safe_state_index = 0,
 258 };
 259
 260 static struct cpuidle_driver omap5_idle_driver = {
 261         .name                           = "omap5_idle",
 262         .owner                          = THIS_MODULE,
 263         .states = {
 264                 {
 265                         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
 266                         .exit_latency = 2 + 2,
 267                         .target_residency = 5,
 268                         .enter = omap_enter_idle_simple,
 269                         .name = "C1",
 270                         .desc = "CPUx WFI, MPUSS ON"
 271                 },
 272                 {
 273                         /* C2 - CPU0 RET + CPU1 RET + MPU CSWR */
 274                         .exit_latency = 48 + 60,
 275                         .target_residency = 100,
 276                         .flags = CPUIDLE_FLAG_TIMER_STOP,
 277                         .enter = omap_enter_idle_smp,
 278                         .name = "C2",
 279                         .desc = "CPUx CSWR, MPUSS CSWR",
 280                 },
 281         },
 282         .state_count = ARRAY_SIZE(omap5_idle_data),
 283         .safe_state_index = 0,
 284 };
 285
 286 /* Public functions */
 287
 288 /**
 289  * omap4_idle_init - Init routine for OMAP4+ idle
 290  *
 291  * Registers the OMAP4+ specific cpuidle driver to the cpuidle
 292  * framework with the valid set of states.
 293  */
 294 int __init omap4_idle_init(void)
 295 {
 296         struct cpuidle_driver *idle_driver;
 297
 298         if (soc_is_omap54xx()) {
 299                 state_ptr = &omap5_idle_data[0];
 300                 idle_driver = &omap5_idle_driver;
 301         } else {
 302                 state_ptr = &omap4_idle_data[0];
 303                 idle_driver = &omap4_idle_driver;
 304         }
 305
 306         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 307         cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
 308         cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
 309         if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
 310                 return -ENODEV;
 311
 312         cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
 313         cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
 314         if (!cpu_clkdm[0] || !cpu_clkdm[1])
 315                 return -ENODEV;
 316
 317         return cpuidle_register(idle_driver, cpu_online_mask);
 318 }