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
  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_driver *drv,
  29                                int index)
  30{
  31        unsigned long allowed_mode = SUSP_SH_SLEEP;
  32        int requested_state = index;
  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        sh_mobile_call_standby(cpuidle_mode[k]);
  50
  51        return k;
  52}
  53
  54static struct cpuidle_driver cpuidle_driver = {
  55        .name   = "sh_idle",
  56        .owner  = THIS_MODULE,
  57        .states = {
  58                {
  59                        .exit_latency = 1,
  60                        .target_residency = 1 * 2,
  61                        .power_usage = 3,
  62                        .enter = cpuidle_sleep_enter,
  63                        .name = "C1",
  64                        .desc = "SuperH Sleep Mode",
  65                },
  66                {
  67                        .exit_latency = 100,
  68                        .target_residency = 1 * 2,
  69                        .power_usage = 1,
  70                        .enter = cpuidle_sleep_enter,
  71                        .name = "C2",
  72                        .desc = "SuperH Sleep Mode [SF]",
  73                        .disabled = true,
  74                },
  75                {
  76                        .exit_latency = 2300,
  77                        .target_residency = 1 * 2,
  78                        .power_usage = 1,
  79                        .enter = cpuidle_sleep_enter,
  80                        .name = "C3",
  81                        .desc = "SuperH Mobile Standby Mode [SF]",
  82                        .disabled = true,
  83                },
  84        },
  85        .safe_state_index = 0,
  86        .state_count = 3,
  87};
  88
  89int __init sh_mobile_setup_cpuidle(void)
  90{
  91        if (sh_mobile_sleep_supported & SUSP_SH_SF)
  92                cpuidle_driver.states[1].disabled = false;
  93
  94        if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
  95                cpuidle_driver.states[2].disabled = false;
  96
  97        return cpuidle_register(&cpuidle_driver, NULL);
  98}
  99