release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/loongson/common/pm.c

   1 /*
   2  * loongson-specific suspend support
   3  *
   4  *  Copyright (C) 2009 Lemote Inc.
   5  *  Author: Wu Zhangjin <wuzhangjin@gmail.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 as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12 #include <linux/suspend.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/pm.h>
  15
  16 #include <asm/i8259.h>
  17 #include <asm/mipsregs.h>
  18
  19 #include <loongson.h>
  20
  21 static unsigned int __maybe_unused cached_master_mask;  /* i8259A */
  22 static unsigned int __maybe_unused cached_slave_mask;
  23 static unsigned int __maybe_unused cached_bonito_irq_mask; /* bonito */
  24
  25 void arch_suspend_disable_irqs(void)
  26 {
  27         /* disable all mips events */
  28         local_irq_disable();
  29
  30 #ifdef CONFIG_I8259
  31         /* disable all events of i8259A */
  32         cached_slave_mask = inb(PIC_SLAVE_IMR);
  33         cached_master_mask = inb(PIC_MASTER_IMR);
  34
  35         outb(0xff, PIC_SLAVE_IMR);
  36         inb(PIC_SLAVE_IMR);
  37         outb(0xff, PIC_MASTER_IMR);
  38         inb(PIC_MASTER_IMR);
  39 #endif
  40         /* disable all events of bonito */
  41         cached_bonito_irq_mask = LOONGSON_INTEN;
  42         LOONGSON_INTENCLR = 0xffff;
  43         (void)LOONGSON_INTENCLR;
  44 }
  45
  46 void arch_suspend_enable_irqs(void)
  47 {
  48         /* enable all mips events */
  49         local_irq_enable();
  50 #ifdef CONFIG_I8259
  51         /* only enable the cached events of i8259A */
  52         outb(cached_slave_mask, PIC_SLAVE_IMR);
  53         outb(cached_master_mask, PIC_MASTER_IMR);
  54 #endif
  55         /* enable all cached events of bonito */
  56         LOONGSON_INTENSET = cached_bonito_irq_mask;
  57         (void)LOONGSON_INTENSET;
  58 }
  59
  60 /*
  61  * Setup the board-specific events for waking up loongson from wait mode
  62  */
  63 void __weak setup_wakeup_events(void)
  64 {
  65 }
  66
  67 /*
  68  * Check wakeup events
  69  */
  70 int __weak wakeup_loongson(void)
  71 {
  72         return 1;
  73 }
  74
  75 /*
  76  * If the events are really what we want to wakeup the CPU, wake it up
  77  * otherwise put the CPU asleep again.
  78  */
  79 static void wait_for_wakeup_events(void)
  80 {
  81         while (!wakeup_loongson())
  82                 LOONGSON_CHIPCFG0 &= ~0x7;
  83 }
  84
  85 /*
  86  * Stop all perf counters
  87  *
  88  * $24 is the control register of Loongson perf counter
  89  */
  90 static inline void stop_perf_counters(void)
  91 {
  92         __write_64bit_c0_register($24, 0, 0);
  93 }
  94
  95
  96 static void loongson_suspend_enter(void)
  97 {
  98         static unsigned int cached_cpu_freq;
  99
 100         /* setup wakeup events via enabling the IRQs */
 101         setup_wakeup_events();
 102
 103         stop_perf_counters();
 104
 105         cached_cpu_freq = LOONGSON_CHIPCFG0;
 106
 107         /* Put CPU into wait mode */
 108         LOONGSON_CHIPCFG0 &= ~0x7;
 109
 110         /* wait for the given events to wakeup cpu from wait mode */
 111         wait_for_wakeup_events();
 112
 113         LOONGSON_CHIPCFG0 = cached_cpu_freq;
 114         mmiowb();
 115 }
 116
 117 void __weak mach_suspend(void)
 118 {
 119 }
 120
 121 void __weak mach_resume(void)
 122 {
 123 }
 124
 125 static int loongson_pm_enter(suspend_state_t state)
 126 {
 127         mach_suspend();
 128
 129         /* processor specific suspend */
 130         loongson_suspend_enter();
 131
 132         mach_resume();
 133
 134         return 0;
 135 }
 136
 137 static int loongson_pm_valid_state(suspend_state_t state)
 138 {
 139         switch (state) {
 140         case PM_SUSPEND_ON:
 141         case PM_SUSPEND_STANDBY:
 142         case PM_SUSPEND_MEM:
 143                 return 1;
 144
 145         default:
 146                 return 0;
 147         }
 148 }
 149
 150 static struct platform_suspend_ops loongson_pm_ops = {
 151         .valid  = loongson_pm_valid_state,
 152         .enter  = loongson_pm_enter,
 153 };
 154
 155 static int __init loongson_pm_init(void)
 156 {
 157         suspend_set_ops(&loongson_pm_ops);
 158
 159         return 0;
 160 }
 161 arch_initcall(loongson_pm_init);