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 <asm/suspend.h>
  18#include <asm/uaccess.h>
  19#include <asm/hwblk.h>
  20
  21static unsigned long cpuidle_mode[] = {
  22        SUSP_SH_SLEEP, /* regular sleep mode */
  23        SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */
  24        SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */
  25};
  26
  27static int cpuidle_sleep_enter(struct cpuidle_device *dev,
  28                               struct cpuidle_state *state)
  29{
  30        unsigned long allowed_mode = arch_hwblk_sleep_mode();
  31        ktime_t before, after;
  32        int requested_state = state - &dev->states[0];
  33        int allowed_state;
  34        int k;
  35
  36        /* convert allowed mode to allowed state */
  37        for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
  38                if (cpuidle_mode[k] == allowed_mode)
  39                        break;
  40
  41        allowed_state = k;
  42
  43        /* take the following into account for sleep mode selection:
  44         * - allowed_state: best mode allowed by hardware (clock deps)
  45         * - requested_state: best mode allowed by software (latencies)
  46         */
  47        k = min_t(int, allowed_state, requested_state);
  48
  49        dev->last_state = &dev->states[k];
  50        before = ktime_get();
  51        sh_mobile_call_standby(cpuidle_mode[k]);
  52        after = ktime_get();
  53        return ktime_to_ns(ktime_sub(after, before)) >> 10;
  54}
  55
  56static struct cpuidle_device cpuidle_dev;
  57static struct cpuidle_driver cpuidle_driver = {
  58        .name =         "sh_idle",
  59        .owner =        THIS_MODULE,
  60};
  61
  62void sh_mobile_setup_cpuidle(void)
  63{
  64        struct cpuidle_device *dev = &cpuidle_dev;
  65        struct cpuidle_state *state;
  66        int i;
  67
  68        cpuidle_register_driver(&cpuidle_driver);
  69
  70        for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
  71                dev->states[i].name[0] = '\0';
  72                dev->states[i].desc[0] = '\0';
  73        }
  74
  75        i = CPUIDLE_DRIVER_STATE_START;
  76
  77        state = &dev->states[i++];
  78        snprintf(state->name, CPUIDLE_NAME_LEN, "C0");
  79        strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN);
  80        state->exit_latency = 1;
  81        state->target_residency = 1 * 2;
  82        state->power_usage = 3;
  83        state->flags = 0;
  84        state->flags |= CPUIDLE_FLAG_TIME_VALID;
  85        state->enter = cpuidle_sleep_enter;
  86
  87        dev->safe_state = state;
  88
  89        if (sh_mobile_sleep_supported & SUSP_SH_SF) {
  90                state = &dev->states[i++];
  91                snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
  92                strncpy(state->desc, "SuperH Sleep Mode [SF]",
  93                        CPUIDLE_DESC_LEN);
  94                state->exit_latency = 100;
  95                state->target_residency = 1 * 2;
  96                state->power_usage = 1;
  97                state->flags = 0;
  98                state->flags |= CPUIDLE_FLAG_TIME_VALID;
  99                state->enter = cpuidle_sleep_enter;
 100        }
 101
 102        if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) {
 103                state = &dev->states[i++];
 104                snprintf(state->name, CPUIDLE_NAME_LEN, "C2");
 105                strncpy(state->desc, "SuperH Mobile Standby Mode [SF]",
 106                        CPUIDLE_DESC_LEN);
 107                state->exit_latency = 2300;
 108                state->target_residency = 1 * 2;
 109                state->power_usage = 1;
 110                state->flags = 0;
 111                state->flags |= CPUIDLE_FLAG_TIME_VALID;
 112                state->enter = cpuidle_sleep_enter;
 113        }
 114
 115        dev->state_count = i;
 116
 117        cpuidle_register_device(dev);
 118}
 119