LXR linux/arch/sh/kernel/cpu/shmobile/cpuidle.c

   1/*
   2 * arch/sh/kernel/cpu/shmobile/cpuidle.c
   3 *
   4 * Cpuidle support code for SuperH Mobile
   5 *
   6 *  Copyright (C) 2009 Magnus Damm
   7 *
   8 * This file is subject to the terms and conditions of the GNU General Public
   9 * License.  See the file "COPYING" in the main directory of this archive
  10 * for more details.
  11 */
  12#include <linux/init.h>
  13#include <linux/kernel.h>
  14#include <linux/io.h>
  15#include <linux/suspend.h>
  16#include <linux/cpuidle.h>
  17#include <linux/export.h>
  18#include <asm/suspend.h>
  19#include <asm/uaccess.h>
  20#include <asm/hwblk.h>
  21
  22static unsigned long cpuidle_mode[] = {
  23        SUSP_SH_SLEEP, /* regular sleep mode */
  24        SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */
  25        SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */
  26};
  27
  28static int cpuidle_sleep_enter(struct cpuidle_device *dev,
  29                                struct cpuidle_driver *drv,
  30                                int index)
  31{
  32        unsigned long allowed_mode = arch_hwblk_sleep_mode();
  33        ktime_t before, after;
  34        int requested_state = index;
  35        int allowed_state;
  36        int k;
  37
  38        /* convert allowed mode to allowed state */
  39        for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
  40                if (cpuidle_mode[k] == allowed_mode)
  41                        break;
  42
  43        allowed_state = k;
  44
  45        /* take the following into account for sleep mode selection:
  46         * - allowed_state: best mode allowed by hardware (clock deps)
  47         * - requested_state: best mode allowed by software (latencies)
  48         */
  49        k = min_t(int, allowed_state, requested_state);
  50
  51        before = ktime_get();
  52        sh_mobile_call_standby(cpuidle_mode[k]);
  53        after = ktime_get();
  54
  55        dev->last_residency = (int)ktime_to_ns(ktime_sub(after, before)) >> 10;
  56
  57        return k;
  58}
  59
  60static struct cpuidle_device cpuidle_dev;
  61static struct cpuidle_driver cpuidle_driver = {
  62        .name =         "sh_idle",
  63        .owner =        THIS_MODULE,
  64};
  65
  66void sh_mobile_setup_cpuidle(void)
  67{
  68        struct cpuidle_device *dev = &cpuidle_dev;
  69        struct cpuidle_driver *drv = &cpuidle_driver;
  70        struct cpuidle_state *state;
  71        int i;
  72
  73
  74        for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
  75                drv->states[i].name[0] = '\0';
  76                drv->states[i].desc[0] = '\0';
  77        }
  78
  79        i = CPUIDLE_DRIVER_STATE_START;
  80
  81        state = &drv->states[i++];
  82        snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
  83        strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN);
  84        state->exit_latency = 1;
  85        state->target_residency = 1 * 2;
  86        state->power_usage = 3;
  87        state->flags = 0;
  88        state->flags |= CPUIDLE_FLAG_TIME_VALID;
  89        state->enter = cpuidle_sleep_enter;
  90
  91        drv->safe_state_index = i-1;
  92
  93        if (sh_mobile_sleep_supported & SUSP_SH_SF) {
  94                state = &drv->states[i++];
  95                snprintf(state->name, CPUIDLE_NAME_LEN, "C2");
  96                strncpy(state->desc, "SuperH Sleep Mode [SF]",
  97                        CPUIDLE_DESC_LEN);
  98                state->exit_latency = 100;
  99                state->target_residency = 1 * 2;
 100                state->power_usage = 1;
 101                state->flags = 0;
 102                state->flags |= CPUIDLE_FLAG_TIME_VALID;
 103                state->enter = cpuidle_sleep_enter;
 104        }
 105
 106        if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) {
 107                state = &drv->states[i++];
 108                snprintf(state->name, CPUIDLE_NAME_LEN, "C3");
 109                strncpy(state->desc, "SuperH Mobile Standby Mode [SF]",
 110                        CPUIDLE_DESC_LEN);
 111                state->exit_latency = 2300;
 112                state->target_residency = 1 * 2;
 113                state->power_usage = 1;
 114                state->flags = 0;
 115                state->flags |= CPUIDLE_FLAG_TIME_VALID;
 116                state->enter = cpuidle_sleep_enter;
 117        }
 118
 119        drv->state_count = i;
 120        dev->state_count = i;
 121
 122        cpuidle_register_driver(&cpuidle_driver);
 123
 124        cpuidle_register_device(dev);
 125}
 126