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
  18 #include <asm/proc-fns.h>
  19
  20 #include "common.h"
  21 #include "pm.h"
  22 #include "prm.h"
  23 #include "clockdomain.h"
  24
  25 /* Machine specific information */
  26 struct idle_statedata {
  27         u32 cpu_state;
  28         u32 mpu_logic_state;
  29         u32 mpu_state;
  30 };
  31
  32 static struct idle_statedata omap4_idle_data[] = {
  33         {
  34                 .cpu_state = PWRDM_POWER_ON,
  35                 .mpu_state = PWRDM_POWER_ON,
  36                 .mpu_logic_state = PWRDM_POWER_RET,
  37         },
  38         {
  39                 .cpu_state = PWRDM_POWER_OFF,
  40                 .mpu_state = PWRDM_POWER_RET,
  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_OFF,
  47         },
  48 };
  49
  50 static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS];
  51 static struct clockdomain *cpu_clkdm[NR_CPUS];
  52
  53 static atomic_t abort_barrier;
  54 static bool cpu_done[NR_CPUS];
  55 static struct idle_statedata *state_ptr = &omap4_idle_data[0];
  56
  57 /* Private functions */
  58
  59 /**
  60  * omap_enter_idle_[simple/coupled] - OMAP4PLUS cpuidle entry functions
  61  * @dev: cpuidle device
  62  * @drv: cpuidle driver
  63  * @index: the index of state to be entered
  64  *
  65  * Called from the CPUidle framework to program the device to the
  66  * specified low power state selected by the governor.
  67  * Returns the amount of time spent in the low power state.
  68  */
  69 static int omap_enter_idle_simple(struct cpuidle_device *dev,
  70                         struct cpuidle_driver *drv,
  71                         int index)
  72 {
  73         local_fiq_disable();
  74         omap_do_wfi();
  75         local_fiq_enable();
  76
  77         return index;
  78 }
  79
  80 static int omap_enter_idle_coupled(struct cpuidle_device *dev,
  81                         struct cpuidle_driver *drv,
  82                         int index)
  83 {
  84         struct idle_statedata *cx = state_ptr + index;
  85
  86         local_fiq_disable();
  87
  88         /*
  89          * CPU0 has to wait and stay ON until CPU1 is OFF state.
  90          * This is necessary to honour hardware recommondation
  91          * of triggeing all the possible low power modes once CPU1 is
  92          * out of coherency and in OFF mode.
  93          */
  94         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
  95                 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
  96                         cpu_relax();
  97
  98                         /*
  99                          * CPU1 could have already entered & exited idle
 100                          * without hitting off because of a wakeup
 101                          * or a failed attempt to hit off mode.  Check for
 102                          * that here, otherwise we could spin forever
 103                          * waiting for CPU1 off.
 104                          */
 105                         if (cpu_done[1])
 106                             goto fail;
 107
 108                 }
 109         }
 110
 111         /*
 112          * Call idle CPU PM enter notifier chain so that
 113          * VFP and per CPU interrupt context is saved.
 114          */
 115         cpu_pm_enter();
 116
 117         if (dev->cpu == 0) {
 118                 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
 119                 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 120
 121                 /*
 122                  * Call idle CPU cluster PM enter notifier chain
 123                  * to save GIC and wakeupgen context.
 124                  */
 125                 if ((cx->mpu_state == PWRDM_POWER_RET) &&
 126                         (cx->mpu_logic_state == PWRDM_POWER_OFF))
 127                                 cpu_cluster_pm_enter();
 128         }
 129
 130         omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 131         cpu_done[dev->cpu] = true;
 132
 133         /* Wakeup CPU1 only if it is not offlined */
 134         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
 135                 clkdm_wakeup(cpu_clkdm[1]);
 136                 clkdm_allow_idle(cpu_clkdm[1]);
 137         }
 138
 139         /*
 140          * Call idle CPU PM exit notifier chain to restore
 141          * VFP and per CPU IRQ context.
 142          */
 143         cpu_pm_exit();
 144
 145         /*
 146          * Call idle CPU cluster PM exit notifier chain
 147          * to restore GIC and wakeupgen context.
 148          */
 149         if ((cx->mpu_state == PWRDM_POWER_RET) &&
 150                 (cx->mpu_logic_state == PWRDM_POWER_OFF))
 151                 cpu_cluster_pm_exit();
 152
 153 fail:
 154         cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
 155         cpu_done[dev->cpu] = false;
 156
 157         local_fiq_enable();
 158
 159         return index;
 160 }
 161
 162 static DEFINE_PER_CPU(struct cpuidle_device, omap_idle_dev);
 163
 164 static struct cpuidle_driver omap4_idle_driver = {
 165         .name                           = "omap4_idle",
 166         .owner                          = THIS_MODULE,
 167         .states = {
 168                 {
 169                         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
 170                         .exit_latency = 2 + 2,
 171                         .target_residency = 5,
 172                         .flags = CPUIDLE_FLAG_TIME_VALID,
 173                         .enter = omap_enter_idle_simple,
 174                         .name = "C1",
 175                         .desc = "CPUx ON, MPUSS ON"
 176                 },
 177                 {
 178                         /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 179                         .exit_latency = 328 + 440,
 180                         .target_residency = 960,
 181                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
 182                                  CPUIDLE_FLAG_TIMER_STOP,
 183                         .enter = omap_enter_idle_coupled,
 184                         .name = "C2",
 185                         .desc = "CPUx OFF, MPUSS CSWR",
 186                 },
 187                 {
 188                         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
 189                         .exit_latency = 460 + 518,
 190                         .target_residency = 1100,
 191                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
 192                                  CPUIDLE_FLAG_TIMER_STOP,
 193                         .enter = omap_enter_idle_coupled,
 194                         .name = "C3",
 195                         .desc = "CPUx OFF, MPUSS OSWR",
 196                 },
 197         },
 198         .state_count = ARRAY_SIZE(omap4_idle_data),
 199         .safe_state_index = 0,
 200 };
 201
 202 /* Public functions */
 203
 204 /**
 205  * omap4_idle_init - Init routine for OMAP4+ idle
 206  *
 207  * Registers the OMAP4+ specific cpuidle driver to the cpuidle
 208  * framework with the valid set of states.
 209  */
 210 int __init omap4_idle_init(void)
 211 {
 212         struct cpuidle_device *dev;
 213         unsigned int cpu_id = 0;
 214
 215         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 216         cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
 217         cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
 218         if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
 219                 return -ENODEV;
 220
 221         cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
 222         cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
 223         if (!cpu_clkdm[0] || !cpu_clkdm[1])
 224                 return -ENODEV;
 225
 226         if (cpuidle_register_driver(&omap4_idle_driver)) {
 227                 pr_err("%s: CPUidle driver register failed\n", __func__);
 228                 return -EIO;
 229         }
 230
 231         for_each_cpu(cpu_id, cpu_online_mask) {
 232                 dev = &per_cpu(omap_idle_dev, cpu_id);
 233                 dev->cpu = cpu_id;
 234 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 235                 dev->coupled_cpus = *cpu_online_mask;
 236 #endif
 237                 if (cpuidle_register_device(dev)) {
 238                         pr_err("%s: CPUidle register failed\n", __func__);
 239                         cpuidle_unregister_driver(&omap4_idle_driver);
 240                         return -EIO;
 241                 }
 242         }
 243
 244         return 0;
 245 }