kernel/arch/unicore32/kernel/pm.c

   1 /*
   2  * linux/arch/unicore32/kernel/pm.c
   3  *
   4  * Code specific to PKUnity SoC and UniCore ISA
   5  *
   6  *      Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
   7  *      Copyright (C) 2001-2010 Guan Xuetao
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  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 #include <linux/io.h>
  19
  20 #include <mach/hardware.h>
  21 #include <mach/pm.h>
  22
  23 #include "setup.h"
  24
  25 struct puv3_cpu_pm_fns *puv3_cpu_pm_fns;
  26 static unsigned long *sleep_save;
  27
  28 int puv3_pm_enter(suspend_state_t state)
  29 {
  30         unsigned long sleep_save_checksum = 0, checksum = 0;
  31         int i;
  32
  33         /* skip registers saving for standby */
  34         if (state != PM_SUSPEND_STANDBY) {
  35                 puv3_cpu_pm_fns->save(sleep_save);
  36                 /* before sleeping, calculate and save a checksum */
  37                 for (i = 0; i < puv3_cpu_pm_fns->save_count - 1; i++)
  38                         sleep_save_checksum += sleep_save[i];
  39         }
  40
  41         /* *** go zzz *** */
  42         puv3_cpu_pm_fns->enter(state);
  43         cpu_init();
  44 #ifdef CONFIG_INPUT_KEYBOARD
  45         puv3_ps2_init();
  46 #endif
  47 #ifdef CONFIG_PCI
  48         pci_puv3_preinit();
  49 #endif
  50         if (state != PM_SUSPEND_STANDBY) {
  51                 /* after sleeping, validate the checksum */
  52                 for (i = 0; i < puv3_cpu_pm_fns->save_count - 1; i++)
  53                         checksum += sleep_save[i];
  54
  55                 /* if invalid, display message and wait for a hardware reset */
  56                 if (checksum != sleep_save_checksum) {
  57                         while (1)
  58                                 puv3_cpu_pm_fns->enter(state);
  59                 }
  60                 puv3_cpu_pm_fns->restore(sleep_save);
  61         }
  62
  63         pr_debug("*** made it back from resume\n");
  64
  65         return 0;
  66 }
  67 EXPORT_SYMBOL_GPL(puv3_pm_enter);
  68
  69 unsigned long sleep_phys_sp(void *sp)
  70 {
  71         return virt_to_phys(sp);
  72 }
  73
  74 static int puv3_pm_valid(suspend_state_t state)
  75 {
  76         if (puv3_cpu_pm_fns)
  77                 return puv3_cpu_pm_fns->valid(state);
  78
  79         return -EINVAL;
  80 }
  81
  82 static int puv3_pm_prepare(void)
  83 {
  84         int ret = 0;
  85
  86         if (puv3_cpu_pm_fns && puv3_cpu_pm_fns->prepare)
  87                 ret = puv3_cpu_pm_fns->prepare();
  88
  89         return ret;
  90 }
  91
  92 static void puv3_pm_finish(void)
  93 {
  94         if (puv3_cpu_pm_fns && puv3_cpu_pm_fns->finish)
  95                 puv3_cpu_pm_fns->finish();
  96 }
  97
  98 static struct platform_suspend_ops puv3_pm_ops = {
  99         .valid          = puv3_pm_valid,
 100         .enter          = puv3_pm_enter,
 101         .prepare        = puv3_pm_prepare,
 102         .finish         = puv3_pm_finish,
 103 };
 104
 105 static int __init puv3_pm_init(void)
 106 {
 107         if (!puv3_cpu_pm_fns) {
 108                 printk(KERN_ERR "no valid puv3_cpu_pm_fns defined\n");
 109                 return -EINVAL;
 110         }
 111
 112         sleep_save = kmalloc(puv3_cpu_pm_fns->save_count
 113                                 * sizeof(unsigned long), GFP_KERNEL);
 114         if (!sleep_save) {
 115                 printk(KERN_ERR "failed to alloc memory for pm save\n");
 116                 return -ENOMEM;
 117         }
 118
 119         suspend_set_ops(&puv3_pm_ops);
 120         return 0;
 121 }
 122
 123 device_initcall(puv3_pm_init);