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
  22 static 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
  28 static 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
  60 static struct cpuidle_device cpuidle_dev;
  61 static struct cpuidle_driver cpuidle_driver = {
  62         .name =         "sh_idle",
  63         .owner =        THIS_MODULE,
  64 };
  65
  66 void 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 }