arch/arm/mach-omap2/cpuidle44xx.c

   1 /*
   2  * OMAP4 CPU idle Routines
   3  *
   4  * Copyright (C) 2011 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/clockchips.h>
  18
  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 omap4_idle_statedata {
  28         u32 cpu_state;
  29         u32 mpu_logic_state;
  30         u32 mpu_state;
  31 };
  32
  33 static struct omap4_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
  57 /**
  58  * omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions
  59  * @dev: cpuidle device
  60  * @drv: cpuidle driver
  61  * @index: the index of state to be entered
  62  *
  63  * Called from the CPUidle framework to program the device to the
  64  * specified low power state selected by the governor.
  65  * Returns the amount of time spent in the low power state.
  66  */
  67 static int omap4_enter_idle_simple(struct cpuidle_device *dev,
  68                         struct cpuidle_driver *drv,
  69                         int index)
  70 {
  71         local_fiq_disable();
  72         omap_do_wfi();
  73         local_fiq_enable();
  74
  75         return index;
  76 }
  77
  78 static int omap4_enter_idle_coupled(struct cpuidle_device *dev,
  79                         struct cpuidle_driver *drv,
  80                         int index)
  81 {
  82         struct omap4_idle_statedata *cx = &omap4_idle_data[index];
  83         int cpu_id = smp_processor_id();
  84
  85         local_fiq_disable();
  86
  87         /*
  88          * CPU0 has to wait and stay ON until CPU1 is OFF state.
  89          * This is necessary to honour hardware recommondation
  90          * of triggeing all the possible low power modes once CPU1 is
  91          * out of coherency and in OFF mode.
  92          */
  93         if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
  94                 while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
  95                         cpu_relax();
  96
  97                         /*
  98                          * CPU1 could have already entered & exited idle
  99                          * without hitting off because of a wakeup
 100                          * or a failed attempt to hit off mode.  Check for
 101                          * that here, otherwise we could spin forever
 102                          * waiting for CPU1 off.
 103                          */
 104                         if (cpu_done[1])
 105                             goto fail;
 106
 107                 }
 108         }
 109
 110         clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
 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 (omap4_mpuss_read_prev_context_state())
 151                 cpu_cluster_pm_exit();
 152
 153         clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
 154
 155 fail:
 156         cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
 157         cpu_done[dev->cpu] = false;
 158
 159         local_fiq_enable();
 160
 161         return index;
 162 }
 163
 164 DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
 165
 166 struct cpuidle_driver omap4_idle_driver = {
 167         .name                           = "omap4_idle",
 168         .owner                          = THIS_MODULE,
 169         .en_core_tk_irqen               = 1,
 170         .states = {
 171                 {
 172                         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
 173                         .exit_latency = 2 + 2,
 174                         .target_residency = 5,
 175                         .flags = CPUIDLE_FLAG_TIME_VALID,
 176                         .enter = omap4_enter_idle_simple,
 177                         .name = "C1",
 178                         .desc = "MPUSS ON"
 179                 },
 180                 {
 181                         /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 182                         .exit_latency = 328 + 440,
 183                         .target_residency = 960,
 184                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
 185                         .enter = omap4_enter_idle_coupled,
 186                         .name = "C2",
 187                         .desc = "MPUSS CSWR",
 188                 },
 189                 {
 190                         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
 191                         .exit_latency = 460 + 518,
 192                         .target_residency = 1100,
 193                         .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
 194                         .enter = omap4_enter_idle_coupled,
 195                         .name = "C3",
 196                         .desc = "MPUSS OSWR",
 197                 },
 198         },
 199         .state_count = ARRAY_SIZE(omap4_idle_data),
 200         .safe_state_index = 0,
 201 };
 202
 203 /*
 204  * For each cpu, setup the broadcast timer because local timers
 205  * stops for the states above C1.
 206  */
 207 static void omap_setup_broadcast_timer(void *arg)
 208 {
 209         int cpu = smp_processor_id();
 210         clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu);
 211 }
 212
 213 /**
 214  * omap4_idle_init - Init routine for OMAP4 idle
 215  *
 216  * Registers the OMAP4 specific cpuidle driver to the cpuidle
 217  * framework with the valid set of states.
 218  */
 219 int __init omap4_idle_init(void)
 220 {
 221         struct cpuidle_device *dev;
 222         unsigned int cpu_id = 0;
 223
 224         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 225         cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
 226         cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
 227         if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
 228                 return -ENODEV;
 229
 230         cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
 231         cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
 232         if (!cpu_clkdm[0] || !cpu_clkdm[1])
 233                 return -ENODEV;
 234
 235         /* Configure the broadcast timer on each cpu */
 236         on_each_cpu(omap_setup_broadcast_timer, NULL, 1);
 237
 238         for_each_cpu(cpu_id, cpu_online_mask) {
 239                 dev = &per_cpu(omap4_idle_dev, cpu_id);
 240                 dev->cpu = cpu_id;
 241 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 242                 dev->coupled_cpus = *cpu_online_mask;
 243 #endif
 244                 cpuidle_register_driver(&omap4_idle_driver);
 245
 246                 if (cpuidle_register_device(dev)) {
 247                         pr_err("%s: CPUidle register failed\n", __func__);
 248                         return -EIO;
 249                 }
 250         }
 251
 252         return 0;
 253 }