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
  25 #ifdef CONFIG_CPU_IDLE
  26
  27 /* Machine specific information to be recorded in the C-state driver_data */
  28 struct omap4_idle_statedata {
  29         u32 cpu_state;
  30         u32 mpu_logic_state;
  31         u32 mpu_state;
  32         u8 valid;
  33 };
  34
  35 static struct cpuidle_params cpuidle_params_table[] = {
  36         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
  37         {.exit_latency = 2 + 2 , .target_residency = 5, .valid = 1},
  38         /* C2- CPU0 OFF + CPU1 OFF + MPU CSWR */
  39         {.exit_latency = 328 + 440 , .target_residency = 960, .valid = 1},
  40         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
  41         {.exit_latency = 460 + 518 , .target_residency = 1100, .valid = 1},
  42 };
  43
  44 #define OMAP4_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
  45
  46 struct omap4_idle_statedata omap4_idle_data[OMAP4_NUM_STATES];
  47 static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd;
  48
  49 /**
  50  * omap4_enter_idle - Programs OMAP4 to enter the specified state
  51  * @dev: cpuidle device
  52  * @drv: cpuidle driver
  53  * @index: the index of state to be entered
  54  *
  55  * Called from the CPUidle framework to program the device to the
  56  * specified low power state selected by the governor.
  57  * Returns the amount of time spent in the low power state.
  58  */
  59 static int omap4_enter_idle(struct cpuidle_device *dev,
  60                         struct cpuidle_driver *drv,
  61                         int index)
  62 {
  63         struct omap4_idle_statedata *cx =
  64                         cpuidle_get_statedata(&dev->states_usage[index]);
  65         struct timespec ts_preidle, ts_postidle, ts_idle;
  66         u32 cpu1_state;
  67         int idle_time;
  68         int cpu_id = smp_processor_id();
  69
  70         /* Used to keep track of the total time in idle */
  71         getnstimeofday(&ts_preidle);
  72
  73         local_irq_disable();
  74         local_fiq_disable();
  75
  76         /*
  77          * CPU0 has to stay ON (i.e in C1) until CPU1 is OFF state.
  78          * This is necessary to honour hardware recommondation
  79          * of triggeing all the possible low power modes once CPU1 is
  80          * out of coherency and in OFF mode.
  81          * Update dev->last_state so that governor stats reflects right
  82          * data.
  83          */
  84         cpu1_state = pwrdm_read_pwrst(cpu1_pd);
  85         if (cpu1_state != PWRDM_POWER_OFF) {
  86                 index = drv->safe_state_index;
  87                 cx = cpuidle_get_statedata(&dev->states_usage[index]);
  88         }
  89
  90         if (index > 0)
  91                 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
  92
  93         /*
  94          * Call idle CPU PM enter notifier chain so that
  95          * VFP and per CPU interrupt context is saved.
  96          */
  97         if (cx->cpu_state == PWRDM_POWER_OFF)
  98                 cpu_pm_enter();
  99
 100         pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
 101         omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
 102
 103         /*
 104          * Call idle CPU cluster PM enter notifier chain
 105          * to save GIC and wakeupgen context.
 106          */
 107         if ((cx->mpu_state == PWRDM_POWER_RET) &&
 108                 (cx->mpu_logic_state == PWRDM_POWER_OFF))
 109                         cpu_cluster_pm_enter();
 110
 111         omap4_enter_lowpower(dev->cpu, cx->cpu_state);
 112
 113         /*
 114          * Call idle CPU PM exit notifier chain to restore
 115          * VFP and per CPU IRQ context. Only CPU0 state is
 116          * considered since CPU1 is managed by CPU hotplug.
 117          */
 118         if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF)
 119                 cpu_pm_exit();
 120
 121         /*
 122          * Call idle CPU cluster PM exit notifier chain
 123          * to restore GIC and wakeupgen context.
 124          */
 125         if (omap4_mpuss_read_prev_context_state())
 126                 cpu_cluster_pm_exit();
 127
 128         if (index > 0)
 129                 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
 130
 131         getnstimeofday(&ts_postidle);
 132         ts_idle = timespec_sub(ts_postidle, ts_preidle);
 133
 134         local_irq_enable();
 135         local_fiq_enable();
 136
 137         idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \
 138                                                                 USEC_PER_SEC;
 139
 140         /* Update cpuidle counters */
 141         dev->last_residency = idle_time;
 142
 143         return index;
 144 }
 145
 146 DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
 147
 148 struct cpuidle_driver omap4_idle_driver = {
 149         .name =         "omap4_idle",
 150         .owner =        THIS_MODULE,
 151 };
 152
 153 static inline void _fill_cstate(struct cpuidle_driver *drv,
 154                                         int idx, const char *descr)
 155 {
 156         struct cpuidle_state *state = &drv->states[idx];
 157
 158         state->exit_latency     = cpuidle_params_table[idx].exit_latency;
 159         state->target_residency = cpuidle_params_table[idx].target_residency;
 160         state->flags            = CPUIDLE_FLAG_TIME_VALID;
 161         state->enter            = omap4_enter_idle;
 162         sprintf(state->name, "C%d", idx + 1);
 163         strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
 164 }
 165
 166 static inline struct omap4_idle_statedata *_fill_cstate_usage(
 167                                         struct cpuidle_device *dev,
 168                                         int idx)
 169 {
 170         struct omap4_idle_statedata *cx = &omap4_idle_data[idx];
 171         struct cpuidle_state_usage *state_usage = &dev->states_usage[idx];
 172
 173         cx->valid               = cpuidle_params_table[idx].valid;
 174         cpuidle_set_statedata(state_usage, cx);
 175
 176         return cx;
 177 }
 178
 179
 180
 181 /**
 182  * omap4_idle_init - Init routine for OMAP4 idle
 183  *
 184  * Registers the OMAP4 specific cpuidle driver to the cpuidle
 185  * framework with the valid set of states.
 186  */
 187 int __init omap4_idle_init(void)
 188 {
 189         struct omap4_idle_statedata *cx;
 190         struct cpuidle_device *dev;
 191         struct cpuidle_driver *drv = &omap4_idle_driver;
 192         unsigned int cpu_id = 0;
 193
 194         mpu_pd = pwrdm_lookup("mpu_pwrdm");
 195         cpu0_pd = pwrdm_lookup("cpu0_pwrdm");
 196         cpu1_pd = pwrdm_lookup("cpu1_pwrdm");
 197         if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd))
 198                 return -ENODEV;
 199
 200
 201         drv->safe_state_index = -1;
 202         dev = &per_cpu(omap4_idle_dev, cpu_id);
 203         dev->cpu = cpu_id;
 204
 205         /* C1 - CPU0 ON + CPU1 ON + MPU ON */
 206         _fill_cstate(drv, 0, "MPUSS ON");
 207         drv->safe_state_index = 0;
 208         cx = _fill_cstate_usage(dev, 0);
 209         cx->valid = 1;  /* C1 is always valid */
 210         cx->cpu_state = PWRDM_POWER_ON;
 211         cx->mpu_state = PWRDM_POWER_ON;
 212         cx->mpu_logic_state = PWRDM_POWER_RET;
 213
 214         /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 215         _fill_cstate(drv, 1, "MPUSS CSWR");
 216         cx = _fill_cstate_usage(dev, 1);
 217         cx->cpu_state = PWRDM_POWER_OFF;
 218         cx->mpu_state = PWRDM_POWER_RET;
 219         cx->mpu_logic_state = PWRDM_POWER_RET;
 220
 221         /* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
 222         _fill_cstate(drv, 2, "MPUSS OSWR");
 223         cx = _fill_cstate_usage(dev, 2);
 224         cx->cpu_state = PWRDM_POWER_OFF;
 225         cx->mpu_state = PWRDM_POWER_RET;
 226         cx->mpu_logic_state = PWRDM_POWER_OFF;
 227
 228         drv->state_count = OMAP4_NUM_STATES;
 229         cpuidle_register_driver(&omap4_idle_driver);
 230
 231         dev->state_count = OMAP4_NUM_STATES;
 232         if (cpuidle_register_device(dev)) {
 233                 pr_err("%s: CPUidle register device failed\n", __func__);
 234                         return -EIO;
 235                 }
 236
 237         return 0;
 238 }
 239 #else
 240 int __init omap4_idle_init(void)
 241 {
 242         return 0;
 243 }
 244 #endif /* CONFIG_CPU_IDLE */