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
arch_suspend_disable_irqs(void)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
arch_suspend_enable_irqs(void)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 */
setup_wakeup_events(void)63 void __weak setup_wakeup_events(void)
64 {
65 }
66
67 /*
68 * Check wakeup events
69 */
wakeup_loongson(void)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 */
wait_for_wakeup_events(void)79 static void wait_for_wakeup_events(void)
80 {
81 while (!wakeup_loongson())
82 LOONGSON_CHIPCFG(0) &= ~0x7;
83 }
84
85 /*
86 * Stop all perf counters
87 *
88 * $24 is the control register of Loongson perf counter
89 */
stop_perf_counters(void)90 static inline void stop_perf_counters(void)
91 {
92 __write_64bit_c0_register($24, 0, 0);
93 }
94
95
loongson_suspend_enter(void)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_CHIPCFG(0);
106
107 /* Put CPU into wait mode */
108 LOONGSON_CHIPCFG(0) &= ~0x7;
109
110 /* wait for the given events to wakeup cpu from wait mode */
111 wait_for_wakeup_events();
112
113 LOONGSON_CHIPCFG(0) = cached_cpu_freq;
114 mmiowb();
115 }
116
mach_suspend(void)117 void __weak mach_suspend(void)
118 {
119 }
120
mach_resume(void)121 void __weak mach_resume(void)
122 {
123 }
124
loongson_pm_enter(suspend_state_t state)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
loongson_pm_valid_state(suspend_state_t state)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 const struct platform_suspend_ops loongson_pm_ops = {
151 .valid = loongson_pm_valid_state,
152 .enter = loongson_pm_enter,
153 };
154
loongson_pm_init(void)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);
162