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         omap_do_wfi();
  75         return index;
  76 }
  77
  78 static int omap_enter_idle_coupled(struct cpuidle_device *dev,
  79                         struct cpuidle_driver *drv,
  80                         int index)
  81 {
  82         struct idle_statedata *cx = state_ptr + index;
  83
  84         /*
  85          * CPU0 has to wait and stay ON until CPU1 is OFF state.
  86          * This is necessary to honour hardware recommondation
  87          * of triggeing all the possible low power modes once CPU1 is
  88          * out of coherency and in OFF mode.
  89          */
  90         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
  91                 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
  92                         cpu_relax();
  93
  94                         /*
  95                          * CPU1 could have already entered & exited idle
  96                          * without hitting off because of a wakeup
  97                          * or a failed attempt to hit off mode.  Check for
  98                          * that here, otherwise we could spin forever
  99                          * waiting for CPU1 off.
 100                          */
 101                         if (cpu_done[1])
 102                             goto fail;
 103
 104                 }
 105         }
 106
 107         /*
 108          * Call idle CPU PM enter notifier chain so that
 109          * VFP and per CPU interrupt context is saved.
 110          */
 111         cpu_pm_enter();
 112
 113         if (dev->cpu == 0) {
 114                 pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
 115                 omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 116
 117                 /*
 118                  * Call idle CPU cluster PM enter notifier chain
 119                  * to save GIC and wakeupgen context.
 120                  */
 121                 if ((cx->mpu_state == PWRDM_POWER_RET) &&
 122                         (cx->mpu_logic_state == PWRDM_POWER_OFF))
 123                                 cpu_cluster_pm_enter();
 124         }
 125
 126         omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 127         cpu_done[dev->cpu] = true;
 128
 129         /* Wakeup CPU1 only if it is not offlined */
 130         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
 131                 clkdm_wakeup(cpu_clkdm[1]);
 132                 omap_set_pwrdm_state(cpu_pd[1], PWRDM_POWER_ON);
 133                 clkdm_allow_idle(cpu_clkdm[1]);
 134         }
 135
 136         /*
 137          * Call idle CPU PM exit notifier chain to restore
 138          * VFP and per CPU IRQ context.
 139          */
 140         cpu_pm_exit();
 141
 142         /*
 143          * Call idle CPU cluster PM exit notifier chain
 144          * to restore GIC and wakeupgen context.
 145          */
 146         if (dev->cpu == 0 && (cx->mpu_state == PWRDM_POWER_RET) &&
 147                 (cx->mpu_logic_state == PWRDM_POWER_OFF))
 148                 cpu_cluster_pm_exit();
 149
 150 fail:
 151         cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
 152         cpu_done[dev->cpu] = false;
 153
 154         return index;
 155 }
 156
 157 static struct cpuidle_driver omap4_idle_driver = {
 158         .name                           = "omap4_idle",
 159         .owner                          = THIS_MODULE,
 160         .states = {
 161                 {
 162                         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
 163                         .exit_latency = 2 + 2,
 164                         .target_residency = 5,
 165                         .flags = CPUIDLE_FLAG_TIME_VALID,
 166                         .enter = omap_enter_idle_simple,
 167                         .name = "C1",
 168                         .desc = "CPUx ON, MPUSS ON"
 169                 },
 170                 {
 171                         /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 172                         .exit_latency = 328 + 440,
 173                         .target_residency = 960,
 174                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
 175                                  CPUIDLE_FLAG_TIMER_STOP,
 176                         .enter = omap_enter_idle_coupled,
 177                         .name = "C2",
 178                         .desc = "CPUx OFF, MPUSS CSWR",
 179                 },
 180                 {
 181                         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
 182                         .exit_latency = 460 + 518,
 183                         .target_residency = 1100,
 184                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED |
 185                                  CPUIDLE_FLAG_TIMER_STOP,
 186                         .enter = omap_enter_idle_coupled,
 187                         .name = "C3",
 188                         .desc = "CPUx OFF, MPUSS OSWR",
 189                 },
 190         },
 191         .state_count = ARRAY_SIZE(omap4_idle_data),
 192         .safe_state_index = 0,
 193 };
 194
 195 /* Public functions */
 196
 197 /**
 198  * omap4_idle_init - Init routine for OMAP4+ idle
 199  *
 200  * Registers the OMAP4+ specific cpuidle driver to the cpuidle
 201  * framework with the valid set of states.
 202  */
 203 int __init omap4_idle_init(void)
 204 {
 205         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 206         cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
 207         cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
 208         if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
 209                 return -ENODEV;
 210
 211         cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
 212         cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
 213         if (!cpu_clkdm[0] || !cpu_clkdm[1])
 214                 return -ENODEV;
 215
 216         return cpuidle_register(&omap4_idle_driver, cpu_online_mask);
 217 }