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 <mach/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         cpu_init();
  46
  47         if (state != PM_SUSPEND_STANDBY && pxa_cpu_pm_fns->restore) {
  48                 /* after sleeping, validate the checksum */
  49                 for (i = 0; i < pxa_cpu_pm_fns->save_count - 1; i++)
  50                         checksum += sleep_save[i];
  51
  52                 /* if invalid, display message and wait for a hardware reset */
  53                 if (checksum != sleep_save_checksum) {
  54
  55                         lubbock_set_hexled(0xbadbadc5);
  56
  57                         while (1)
  58                                 pxa_cpu_pm_fns->enter(state);
  59                 }
  60                 pxa_cpu_pm_fns->restore(sleep_save);
  61         }
  62
  63         pr_debug("*** made it back from resume\n");
  64
  65         return 0;
  66 }
  67
  68 EXPORT_SYMBOL_GPL(pxa_pm_enter);
  69
  70 static int pxa_pm_valid(suspend_state_t state)
  71 {
  72         if (pxa_cpu_pm_fns)
  73                 return pxa_cpu_pm_fns->valid(state);
  74
  75         return -EINVAL;
  76 }
  77
  78 int pxa_pm_prepare(void)
  79 {
  80         int ret = 0;
  81
  82         if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->prepare)
  83                 ret = pxa_cpu_pm_fns->prepare();
  84
  85         return ret;
  86 }
  87
  88 void pxa_pm_finish(void)
  89 {
  90         if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->finish)
  91                 pxa_cpu_pm_fns->finish();
  92 }
  93
  94 static const struct platform_suspend_ops pxa_pm_ops = {
  95         .valid          = pxa_pm_valid,
  96         .enter          = pxa_pm_enter,
  97         .prepare        = pxa_pm_prepare,
  98         .finish         = pxa_pm_finish,
  99 };
 100
 101 static int __init pxa_pm_init(void)
 102 {
 103         if (!pxa_cpu_pm_fns) {
 104                 printk(KERN_ERR "no valid pxa_cpu_pm_fns defined\n");
 105                 return -EINVAL;
 106         }
 107
 108         sleep_save = kmalloc(pxa_cpu_pm_fns->save_count * sizeof(unsigned long),
 109                              GFP_KERNEL);
 110         if (!sleep_save) {
 111                 printk(KERN_ERR "failed to alloc memory for pm save\n");
 112                 return -ENOMEM;
 113         }
 114
 115         suspend_set_ops(&pxa_pm_ops);
 116         return 0;
 117 }
 118
 119 device_initcall(pxa_pm_init);