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 <linux/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_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
  89 int __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 }