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/cpuidle.h>
  19 #include <asm/proc-fns.h>
  20
  21 #include "common.h"
  22 #include "pm.h"
  23 #include "prm.h"
  24 #include "clockdomain.h"
  25
  26 /* Machine specific information */
  27 struct idle_statedata {
  28         u32 cpu_state;
  29         u32 mpu_logic_state;
  30         u32 mpu_state;
  31 };
  32
  33 static struct idle_statedata omap4_idle_data[] = {
  34         {
  35                 .cpu_state = PWRDM_POWER_ON,
  36                 .mpu_state = PWRDM_POWER_ON,
  37                 .mpu_logic_state = PWRDM_POWER_RET,
  38         },
  39         {
  40                 .cpu_state = PWRDM_POWER_OFF,
  41                 .mpu_state = PWRDM_POWER_RET,
  42                 .mpu_logic_state = PWRDM_POWER_RET,
  43         },
  44         {
  45                 .cpu_state = PWRDM_POWER_OFF,
  46                 .mpu_state = PWRDM_POWER_RET,
  47                 .mpu_logic_state = PWRDM_POWER_OFF,
  48         },
  49 };
  50
  51 static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS];
  52 static struct clockdomain *cpu_clkdm[NR_CPUS];
  53
  54 static atomic_t abort_barrier;
  55 static bool cpu_done[NR_CPUS];
  56 static struct idle_statedata *state_ptr = &omap4_idle_data[0];
  57
  58 /* Private functions */
  59
  60 /**
  61  * omap_enter_idle_[simple/coupled] - OMAP4PLUS cpuidle entry functions
  62  * @dev: cpuidle device
  63  * @drv: cpuidle driver
  64  * @index: the index of state to be entered
  65  *
  66  * Called from the CPUidle framework to program the device to the
  67  * specified low power state selected by the governor.
  68  * Returns the amount of time spent in the low power state.
  69  */
  70 static int omap_enter_idle_simple(struct cpuidle_device *dev,
  71                         struct cpuidle_driver *drv,
  72                         int index)
  73 {
  74         local_fiq_disable();
  75         omap_do_wfi();
  76         local_fiq_enable();
  77
  78         return index;
  79 }
  80
  81 static int omap_enter_idle_coupled(struct cpuidle_device *dev,
  82                         struct cpuidle_driver *drv,
  83                         int index)
  84 {
  85         struct idle_statedata *cx = state_ptr + index;
  86
  87         local_fiq_disable();
  88
  89         /*
  90          * CPU0 has to wait and stay ON until CPU1 is OFF state.
  91          * This is necessary to honour hardware recommondation
  92          * of triggeing all the possible low power modes once CPU1 is
  93          * out of coherency and in OFF mode.
  94          */
  95         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
  96                 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
  97                         cpu_relax();
  98
  99                         /*
 100                          * CPU1 could have already entered & exited idle
 101                          * without hitting off because of a wakeup
 102                          * or a failed attempt to hit off mode.  Check for
 103                          * that here, otherwise we could spin forever
 104                          * waiting for CPU1 off.
 105                          */
 106                         if (cpu_done[1])
 107                             goto fail;
 108
 109                 }
 110         }
 111
 112         /*
 113          * Call idle CPU PM enter notifier chain so that
 114          * VFP and per CPU interrupt context is saved.
 115          */
 116         cpu_pm_enter();
 117
 118         if (dev->cpu == 0) {
 119                 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
 120                 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 121
 122                 /*
 123                  * Call idle CPU cluster PM enter notifier chain
 124                  * to save GIC and wakeupgen context.
 125                  */
 126                 if ((cx->mpu_state == PWRDM_POWER_RET) &&
 127                         (cx->mpu_logic_state == PWRDM_POWER_OFF))
 128                                 cpu_cluster_pm_enter();
 129         }
 130
 131         omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 132         cpu_done[dev->cpu] = true;
 133
 134         /* Wakeup CPU1 only if it is not offlined */
 135         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
 136                 clkdm_wakeup(cpu_clkdm[1]);
 137                 clkdm_allow_idle(cpu_clkdm[1]);
 138         }
 139
 140         /*
 141          * Call idle CPU PM exit notifier chain to restore
 142          * VFP and per CPU IRQ context.
 143          */
 144         cpu_pm_exit();
 145
 146         /*
 147          * Call idle CPU cluster PM exit notifier chain
 148          * to restore GIC and wakeupgen context.
 149          */
 150         if ((cx->mpu_state == PWRDM_POWER_RET) &&
 151                 (cx->mpu_logic_state == PWRDM_POWER_OFF))
 152                 cpu_cluster_pm_exit();
 153
 154 fail:
 155         cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
 156         cpu_done[dev->cpu] = false;
 157
 158         local_fiq_enable();
 159
 160         return index;
 161 }
 162
 163 static struct cpuidle_driver omap4_idle_driver = {
 164         .name                           = "omap4_idle",
 165         .owner                          = THIS_MODULE,
 166         .states = {
 167                 {
 168                         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
 169                         .exit_latency = 2 + 2,
 170                         .target_residency = 5,
 171                         .flags = CPUIDLE_FLAG_TIME_VALID,
 172                         .enter = omap_enter_idle_simple,
 173                         .name = "C1",
 174                         .desc = "CPUx ON, MPUSS ON"
 175                 },
 176                 {
 177                         /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 178                         .exit_latency = 328 + 440,
 179                         .target_residency = 960,
 180                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
 181                                  CPUIDLE_FLAG_TIMER_STOP,
 182                         .enter = omap_enter_idle_coupled,
 183                         .name = "C2",
 184                         .desc = "CPUx OFF, MPUSS CSWR",
 185                 },
 186                 {
 187                         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
 188                         .exit_latency = 460 + 518,
 189                         .target_residency = 1100,
 190                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
 191                                  CPUIDLE_FLAG_TIMER_STOP,
 192                         .enter = omap_enter_idle_coupled,
 193                         .name = "C3",
 194                         .desc = "CPUx OFF, MPUSS OSWR",
 195                 },
 196         },
 197         .state_count = ARRAY_SIZE(omap4_idle_data),
 198         .safe_state_index = 0,
 199 };
 200
 201 /* Public functions */
 202
 203 /**
 204  * omap4_idle_init - Init routine for OMAP4+ idle
 205  *
 206  * Registers the OMAP4+ specific cpuidle driver to the cpuidle
 207  * framework with the valid set of states.
 208  */
 209 int __init omap4_idle_init(void)
 210 {
 211         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 212         cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
 213         cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
 214         if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
 215                 return -ENODEV;
 216
 217         cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
 218         cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
 219         if (!cpu_clkdm[0] || !cpu_clkdm[1])
 220                 return -ENODEV;
 221
 222         return cpuidle_register(&omap4_idle_driver, cpu_online_mask);
 223 }