arch/unicore32/kernel/pm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/arch/unicore32/kernel/pm.c
   4  *
   5  * Code specific to PKUnity SoC and UniCore ISA
   6  *
   7  *      Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
   8  *      Copyright (C) 2001-2010 Guan Xuetao
   9  */
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/suspend.h>
  13 #include <linux/errno.h>
  14 #include <linux/slab.h>
  15 #include <linux/io.h>
  16
  17 #include <mach/hardware.h>
  18 #include <mach/pm.h>
  19
  20 #include "setup.h"
  21
  22 struct puv3_cpu_pm_fns *puv3_cpu_pm_fns;
  23 static unsigned long *sleep_save;
  24
  25 int puv3_pm_enter(suspend_state_t state)
  26 {
  27         unsigned long sleep_save_checksum = 0, checksum = 0;
  28         int i;
  29
  30         /* skip registers saving for standby */
  31         if (state != PM_SUSPEND_STANDBY) {
  32                 puv3_cpu_pm_fns->save(sleep_save);
  33                 /* before sleeping, calculate and save a checksum */
  34                 for (i = 0; i < puv3_cpu_pm_fns->save_count - 1; i++)
  35                         sleep_save_checksum += sleep_save[i];
  36         }
  37
  38         /* *** go zzz *** */
  39         puv3_cpu_pm_fns->enter(state);
  40         cpu_init();
  41 #ifdef CONFIG_INPUT_KEYBOARD
  42         puv3_ps2_init();
  43 #endif
  44 #ifdef CONFIG_PCI
  45         pci_puv3_preinit();
  46 #endif
  47         if (state != PM_SUSPEND_STANDBY) {
  48                 /* after sleeping, validate the checksum */
  49                 for (i = 0; i < puv3_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                         while (1)
  55                                 puv3_cpu_pm_fns->enter(state);
  56                 }
  57                 puv3_cpu_pm_fns->restore(sleep_save);
  58         }
  59
  60         pr_debug("*** made it back from resume\n");
  61
  62         return 0;
  63 }
  64 EXPORT_SYMBOL_GPL(puv3_pm_enter);
  65
  66 unsigned long sleep_phys_sp(void *sp)
  67 {
  68         return virt_to_phys(sp);
  69 }
  70
  71 static int puv3_pm_valid(suspend_state_t state)
  72 {
  73         if (puv3_cpu_pm_fns)
  74                 return puv3_cpu_pm_fns->valid(state);
  75
  76         return -EINVAL;
  77 }
  78
  79 static int puv3_pm_prepare(void)
  80 {
  81         int ret = 0;
  82
  83         if (puv3_cpu_pm_fns && puv3_cpu_pm_fns->prepare)
  84                 ret = puv3_cpu_pm_fns->prepare();
  85
  86         return ret;
  87 }
  88
  89 static void puv3_pm_finish(void)
  90 {
  91         if (puv3_cpu_pm_fns && puv3_cpu_pm_fns->finish)
  92                 puv3_cpu_pm_fns->finish();
  93 }
  94
  95 static struct platform_suspend_ops puv3_pm_ops = {
  96         .valid          = puv3_pm_valid,
  97         .enter          = puv3_pm_enter,
  98         .prepare        = puv3_pm_prepare,
  99         .finish         = puv3_pm_finish,
 100 };
 101
 102 static int __init puv3_pm_init(void)
 103 {
 104         if (!puv3_cpu_pm_fns) {
 105                 printk(KERN_ERR "no valid puv3_cpu_pm_fns defined\n");
 106                 return -EINVAL;
 107         }
 108
 109         sleep_save = kmalloc_array(puv3_cpu_pm_fns->save_count,
 110                                    sizeof(unsigned long),
 111                                    GFP_KERNEL);
 112         if (!sleep_save) {
 113                 printk(KERN_ERR "failed to alloc memory for pm save\n");
 114                 return -ENOMEM;
 115         }
 116
 117         suspend_set_ops(&puv3_pm_ops);
 118         return 0;
 119 }
 120
 121 device_initcall(puv3_pm_init);