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);