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
  21 static 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
  27 static 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
  54 static struct cpuidle_device cpuidle_dev;
  55 static struct cpuidle_driver cpuidle_driver = {
  56         .name                   = "sh_idle",
  57         .owner                  = THIS_MODULE,
  58         .en_core_tk_irqen       = 1,
  59 };
  60
  61 void sh_mobile_setup_cpuidle(void)
  62 {
  63         struct cpuidle_device *dev = &cpuidle_dev;
  64         struct cpuidle_driver *drv = &cpuidle_driver;
  65         struct cpuidle_state *state;
  66         int i;
  67
  68         i = CPUIDLE_DRIVER_STATE_START;
  69
  70         state = &drv->states[i++];
  71         snprintf(state->name, CPUIDLE_NAME_LEN, "C1");
  72         strncpy(state->desc, "SuperH Sleep Mode", CPUIDLE_DESC_LEN);
  73         state->exit_latency = 1;
  74         state->target_residency = 1 * 2;
  75         state->power_usage = 3;
  76         state->flags = 0;
  77         state->flags |= CPUIDLE_FLAG_TIME_VALID;
  78         state->enter = cpuidle_sleep_enter;
  79
  80         drv->safe_state_index = i-1;
  81
  82         if (sh_mobile_sleep_supported & SUSP_SH_SF) {
  83                 state = &drv->states[i++];
  84                 snprintf(state->name, CPUIDLE_NAME_LEN, "C2");
  85                 strncpy(state->desc, "SuperH Sleep Mode [SF]",
  86                         CPUIDLE_DESC_LEN);
  87                 state->exit_latency = 100;
  88                 state->target_residency = 1 * 2;
  89                 state->power_usage = 1;
  90                 state->flags = 0;
  91                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
  92                 state->enter = cpuidle_sleep_enter;
  93         }
  94
  95         if (sh_mobile_sleep_supported & SUSP_SH_STANDBY) {
  96                 state = &drv->states[i++];
  97                 snprintf(state->name, CPUIDLE_NAME_LEN, "C3");
  98                 strncpy(state->desc, "SuperH Mobile Standby Mode [SF]",
  99                         CPUIDLE_DESC_LEN);
 100                 state->exit_latency = 2300;
 101                 state->target_residency = 1 * 2;
 102                 state->power_usage = 1;
 103                 state->flags = 0;
 104                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
 105                 state->enter = cpuidle_sleep_enter;
 106         }
 107
 108         drv->state_count = i;
 109         dev->state_count = i;
 110
 111         cpuidle_register_driver(&cpuidle_driver);
 112
 113         cpuidle_register_device(dev);
 114 }