arch/arm/mach-pxa/pm.c

   1 /*
   2  * PXA250/210 Power Management Routines
   3  *
   4  * Original code for the SA11x0:
   5  * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
   6  *
   7  * Modified for the PXA250 by Nicolas Pitre:
   8  * Copyright (c) 2002 Monta Vista Software, Inc.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License.
  12  */
  13 #include <linux/init.h>
  14 #include <linux/module.h>
  15 #include <linux/suspend.h>
  16 #include <linux/errno.h>
  17 #include <linux/slab.h>
  18
  19 #include "pm.h"
  20
  21 struct pxa_cpu_pm_fns *pxa_cpu_pm_fns;
  22 static unsigned long *sleep_save;
  23
  24 int pxa_pm_enter(suspend_state_t state)
  25 {
  26         unsigned long sleep_save_checksum = 0, checksum = 0;
  27         int i;
  28
  29 #ifdef CONFIG_IWMMXT
  30         /* force any iWMMXt context to ram **/
  31         if (elf_hwcap & HWCAP_IWMMXT)
  32                 iwmmxt_task_disable(NULL);
  33 #endif
  34
  35         /* skip registers saving for standby */
  36         if (state != PM_SUSPEND_STANDBY && pxa_cpu_pm_fns->save) {
  37                 pxa_cpu_pm_fns->save(sleep_save);
  38                 /* before sleeping, calculate and save a checksum */
  39                 for (i = 0; i < pxa_cpu_pm_fns->save_count - 1; i++)
  40                         sleep_save_checksum += sleep_save[i];
  41         }
  42
  43         /* *** go zzz *** */
  44         pxa_cpu_pm_fns->enter(state);
  45
  46         if (state != PM_SUSPEND_STANDBY && pxa_cpu_pm_fns->restore) {
  47                 /* after sleeping, validate the checksum */
  48                 for (i = 0; i < pxa_cpu_pm_fns->save_count - 1; i++)
  49                         checksum += sleep_save[i];
  50
  51                 /* if invalid, display message and wait for a hardware reset */
  52                 if (checksum != sleep_save_checksum) {
  53
  54                         while (1)
  55                                 pxa_cpu_pm_fns->enter(state);
  56                 }
  57                 pxa_cpu_pm_fns->restore(sleep_save);
  58         }
  59
  60         pr_debug("*** made it back from resume\n");
  61
  62         return 0;
  63 }
  64
  65 EXPORT_SYMBOL_GPL(pxa_pm_enter);
  66
  67 static int pxa_pm_valid(suspend_state_t state)
  68 {
  69         if (pxa_cpu_pm_fns)
  70                 return pxa_cpu_pm_fns->valid(state);
  71
  72         return -EINVAL;
  73 }
  74
  75 int pxa_pm_prepare(void)
  76 {
  77         int ret = 0;
  78
  79         if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->prepare)
  80                 ret = pxa_cpu_pm_fns->prepare();
  81
  82         return ret;
  83 }
  84
  85 void pxa_pm_finish(void)
  86 {
  87         if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->finish)
  88                 pxa_cpu_pm_fns->finish();
  89 }
  90
  91 static const struct platform_suspend_ops pxa_pm_ops = {
  92         .valid          = pxa_pm_valid,
  93         .enter          = pxa_pm_enter,
  94         .prepare        = pxa_pm_prepare,
  95         .finish         = pxa_pm_finish,
  96 };
  97
  98 static int __init pxa_pm_init(void)
  99 {
 100         if (!pxa_cpu_pm_fns) {
 101                 printk(KERN_ERR "no valid pxa_cpu_pm_fns defined\n");
 102                 return -EINVAL;
 103         }
 104
 105         sleep_save = kmalloc_array(pxa_cpu_pm_fns->save_count,
 106                                    sizeof(*sleep_save),
 107                                    GFP_KERNEL);
 108         if (!sleep_save)
 109                 return -ENOMEM;
 110
 111         suspend_set_ops(&pxa_pm_ops);
 112         return 0;
 113 }
 114
 115 device_initcall(pxa_pm_init);