arch/sh/kernel/cpu/shmobile/cpuidle.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sh/kernel/cpu/shmobile/cpuidle.c
   4  *
   5  * Cpuidle support code for SuperH Mobile
   6  *
   7  *  Copyright (C) 2009 Magnus Damm
   8  */
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/io.h>
  12 #include <linux/suspend.h>
  13 #include <linux/cpuidle.h>
  14 #include <linux/export.h>
  15 #include <asm/suspend.h>
  16 #include <linux/uaccess.h>
  17
  18 static unsigned long cpuidle_mode[] = {
  19         SUSP_SH_SLEEP, /* regular sleep mode */
  20         SUSP_SH_SLEEP | SUSP_SH_SF, /* sleep mode + self refresh */
  21         SUSP_SH_STANDBY | SUSP_SH_SF, /* software standby mode + self refresh */
  22 };
  23
  24 static int cpuidle_sleep_enter(struct cpuidle_device *dev,
  25                                 struct cpuidle_driver *drv,
  26                                 int index)
  27 {
  28         unsigned long allowed_mode = SUSP_SH_SLEEP;
  29         int requested_state = index;
  30         int allowed_state;
  31         int k;
  32
  33         /* convert allowed mode to allowed state */
  34         for (k = ARRAY_SIZE(cpuidle_mode) - 1; k > 0; k--)
  35                 if (cpuidle_mode[k] == allowed_mode)
  36                         break;
  37
  38         allowed_state = k;
  39
  40         /* take the following into account for sleep mode selection:
  41          * - allowed_state: best mode allowed by hardware (clock deps)
  42          * - requested_state: best mode allowed by software (latencies)
  43          */
  44         k = min_t(int, allowed_state, requested_state);
  45
  46         sh_mobile_call_standby(cpuidle_mode[k]);
  47
  48         return k;
  49 }
  50
  51 static struct cpuidle_driver cpuidle_driver = {
  52         .name   = "sh_idle",
  53         .owner  = THIS_MODULE,
  54         .states = {
  55                 {
  56                         .exit_latency = 1,
  57                         .target_residency = 1 * 2,
  58                         .power_usage = 3,
  59                         .enter = cpuidle_sleep_enter,
  60                         .name = "C1",
  61                         .desc = "SuperH Sleep Mode",
  62                 },
  63                 {
  64                         .exit_latency = 100,
  65                         .target_residency = 1 * 2,
  66                         .power_usage = 1,
  67                         .enter = cpuidle_sleep_enter,
  68                         .name = "C2",
  69                         .desc = "SuperH Sleep Mode [SF]",
  70                         .flags = CPUIDLE_FLAG_UNUSABLE,
  71                 },
  72                 {
  73                         .exit_latency = 2300,
  74                         .target_residency = 1 * 2,
  75                         .power_usage = 1,
  76                         .enter = cpuidle_sleep_enter,
  77                         .name = "C3",
  78                         .desc = "SuperH Mobile Standby Mode [SF]",
  79                         .flags = CPUIDLE_FLAG_UNUSABLE,
  80                 },
  81         },
  82         .safe_state_index = 0,
  83         .state_count = 3,
  84 };
  85
  86 int __init sh_mobile_setup_cpuidle(void)
  87 {
  88         if (sh_mobile_sleep_supported & SUSP_SH_SF)
  89                 cpuidle_driver.states[1].flags = CPUIDLE_FLAG_NONE;
  90
  91         if (sh_mobile_sleep_supported & SUSP_SH_STANDBY)
  92                 cpuidle_driver.states[2].flags = CPUIDLE_FLAG_NONE;
  93
  94         return cpuidle_register(&cpuidle_driver, NULL);
  95 }