LXR linux/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
  21static unsigned int __maybe_unused cached_master_mask;  /* i8259A */
  22static unsigned int __maybe_unused cached_slave_mask;
  23static unsigned int __maybe_unused cached_bonito_irq_mask; /* bonito */
  24
  25void 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
  46void 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 */
  63void __weak setup_wakeup_events(void)
  64{
  65}
  66
  67/*
  68 * Check wakeup events
  69 */
  70int __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 */
  79static 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 */
  90static inline void stop_perf_counters(void)
  91{
  92        __write_64bit_c0_register($24, 0, 0);
  93}
  94
  95
  96static 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
 117void __weak mach_suspend(void)
 118{
 119}
 120
 121void __weak mach_resume(void)
 122{
 123}
 124
 125static 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
 137static 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
 150static const struct platform_suspend_ops loongson_pm_ops = {
 151        .valid  = loongson_pm_valid_state,
 152        .enter  = loongson_pm_enter,
 153};
 154
 155static int __init loongson_pm_init(void)
 156{
 157        suspend_set_ops(&loongson_pm_ops);
 158
 159        return 0;
 160}
 161arch_initcall(loongson_pm_init);
 162