arch/arm/mach-omap2/pm44xx.c

   1 /*
   2  * OMAP4 Power Management Routines
   3  *
   4  * Copyright (C) 2010 Texas Instruments, Inc.
   5  * Rajendra Nayak <rnayak@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/pm.h>
  13 #include <linux/suspend.h>
  14 #include <linux/module.h>
  15 #include <linux/list.h>
  16 #include <linux/err.h>
  17 #include <linux/slab.h>
  18
  19 #include <plat/powerdomain.h>
  20 #include <mach/omap4-common.h>
  21
  22 struct power_state {
  23         struct powerdomain *pwrdm;
  24         u32 next_state;
  25 #ifdef CONFIG_SUSPEND
  26         u32 saved_state;
  27 #endif
  28         struct list_head node;
  29 };
  30
  31 static LIST_HEAD(pwrst_list);
  32
  33 #ifdef CONFIG_SUSPEND
  34 static int omap4_pm_prepare(void)
  35 {
  36         disable_hlt();
  37         return 0;
  38 }
  39
  40 static int omap4_pm_suspend(void)
  41 {
  42         do_wfi();
  43         return 0;
  44 }
  45
  46 static int omap4_pm_enter(suspend_state_t suspend_state)
  47 {
  48         int ret = 0;
  49
  50         switch (suspend_state) {
  51         case PM_SUSPEND_STANDBY:
  52         case PM_SUSPEND_MEM:
  53                 ret = omap4_pm_suspend();
  54                 break;
  55         default:
  56                 ret = -EINVAL;
  57         }
  58
  59         return ret;
  60 }
  61
  62 static void omap4_pm_finish(void)
  63 {
  64         enable_hlt();
  65         return;
  66 }
  67
  68 static int omap4_pm_begin(suspend_state_t state)
  69 {
  70         return 0;
  71 }
  72
  73 static void omap4_pm_end(void)
  74 {
  75         return;
  76 }
  77
  78 static struct platform_suspend_ops omap_pm_ops = {
  79         .begin          = omap4_pm_begin,
  80         .end            = omap4_pm_end,
  81         .prepare        = omap4_pm_prepare,
  82         .enter          = omap4_pm_enter,
  83         .finish         = omap4_pm_finish,
  84         .valid          = suspend_valid_only_mem,
  85 };
  86 #endif /* CONFIG_SUSPEND */
  87
  88 static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
  89 {
  90         struct power_state *pwrst;
  91
  92         if (!pwrdm->pwrsts)
  93                 return 0;
  94
  95         pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
  96         if (!pwrst)
  97                 return -ENOMEM;
  98         pwrst->pwrdm = pwrdm;
  99         pwrst->next_state = PWRDM_POWER_ON;
 100         list_add(&pwrst->node, &pwrst_list);
 101
 102         return pwrdm_set_next_pwrst(pwrst->pwrdm, pwrst->next_state);
 103 }
 104
 105 /**
 106  * omap4_pm_init - Init routine for OMAP4 PM
 107  *
 108  * Initializes all powerdomain and clockdomain target states
 109  * and all PRCM settings.
 110  */
 111 static int __init omap4_pm_init(void)
 112 {
 113         int ret;
 114
 115         if (!cpu_is_omap44xx())
 116                 return -ENODEV;
 117
 118         pr_err("Power Management for TI OMAP4.\n");
 119
 120 #ifdef CONFIG_PM
 121         ret = pwrdm_for_each(pwrdms_setup, NULL);
 122         if (ret) {
 123                 pr_err("Failed to setup powerdomains\n");
 124                 goto err2;
 125         }
 126 #endif
 127
 128 #ifdef CONFIG_SUSPEND
 129         suspend_set_ops(&omap_pm_ops);
 130 #endif /* CONFIG_SUSPEND */
 131
 132 err2:
 133         return ret;
 134 }
 135 late_initcall(omap4_pm_init);