1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * loongson-specific suspend support 4 * 5 * Copyright (C) 2009 Lemote Inc. 6 * Author: Wu Zhangjin <wuzhangjin@gmail.com> 7 */ 8 #include <linux/suspend.h> 9 #include <linux/interrupt.h> 10 #include <linux/pm.h> 11 12 #include <asm/i8259.h> 13 #include <asm/mipsregs.h> 14 15 #include <loongson.h> 16 17 static unsigned int __maybe_unused cached_master_mask; /* i8259A */ 18 static unsigned int __maybe_unused cached_slave_mask; 19 static unsigned int __maybe_unused cached_bonito_irq_mask; /* bonito */ 20 21 void arch_suspend_disable_irqs(void) 22 { 23 /* disable all mips events */ 24 local_irq_disable(); 25 26 #ifdef CONFIG_I8259 27 /* disable all events of i8259A */ 28 cached_slave_mask = inb(PIC_SLAVE_IMR); 29 cached_master_mask = inb(PIC_MASTER_IMR); 30 31 outb(0xff, PIC_SLAVE_IMR); 32 inb(PIC_SLAVE_IMR); 33 outb(0xff, PIC_MASTER_IMR); 34 inb(PIC_MASTER_IMR); 35 #endif 36 /* disable all events of bonito */ 37 cached_bonito_irq_mask = LOONGSON_INTEN; 38 LOONGSON_INTENCLR = 0xffff; 39 (void)LOONGSON_INTENCLR; 40 } 41 42 void arch_suspend_enable_irqs(void) 43 { 44 /* enable all mips events */ 45 local_irq_enable(); 46 #ifdef CONFIG_I8259 47 /* only enable the cached events of i8259A */ 48 outb(cached_slave_mask, PIC_SLAVE_IMR); 49 outb(cached_master_mask, PIC_MASTER_IMR); 50 #endif 51 /* enable all cached events of bonito */ 52 LOONGSON_INTENSET = cached_bonito_irq_mask; 53 (void)LOONGSON_INTENSET; 54 } 55 56 /* 57 * Setup the board-specific events for waking up loongson from wait mode 58 */ 59 void __weak setup_wakeup_events(void) 60 { 61 } 62 63 /* 64 * Check wakeup events 65 */ 66 int __weak wakeup_loongson(void) 67 { 68 return 1; 69 } 70 71 /* 72 * If the events are really what we want to wakeup the CPU, wake it up 73 * otherwise put the CPU asleep again. 74 */ 75 static void wait_for_wakeup_events(void) 76 { 77 while (!wakeup_loongson()) 78 writel(readl(LOONGSON_CHIPCFG) & ~0x7, LOONGSON_CHIPCFG); 79 } 80 81 /* 82 * Stop all perf counters 83 * 84 * $24 is the control register of Loongson perf counter 85 */ 86 static inline void stop_perf_counters(void) 87 { 88 __write_64bit_c0_register($24, 0, 0); 89 } 90 91 92 static void loongson_suspend_enter(void) 93 { 94 unsigned int cached_cpu_freq; 95 96 /* setup wakeup events via enabling the IRQs */ 97 setup_wakeup_events(); 98 99 stop_perf_counters(); 100 101 cached_cpu_freq = readl(LOONGSON_CHIPCFG); 102 103 /* Put CPU into wait mode */ 104 writel(readl(LOONGSON_CHIPCFG) & ~0x7, LOONGSON_CHIPCFG); 105 106 /* wait for the given events to wakeup cpu from wait mode */ 107 wait_for_wakeup_events(); 108 109 writel(cached_cpu_freq, LOONGSON_CHIPCFG); 110 111 mmiowb(); 112 } 113 114 void __weak mach_suspend(void) 115 { 116 } 117 118 void __weak mach_resume(void) 119 { 120 } 121 122 static int loongson_pm_enter(suspend_state_t state) 123 { 124 mach_suspend(); 125 126 /* processor specific suspend */ 127 loongson_suspend_enter(); 128 129 mach_resume(); 130 131 return 0; 132 } 133 134 static int loongson_pm_valid_state(suspend_state_t state) 135 { 136 switch (state) { 137 case PM_SUSPEND_ON: 138 case PM_SUSPEND_STANDBY: 139 case PM_SUSPEND_MEM: 140 return 1; 141 142 default: 143 return 0; 144 } 145 } 146 147 static const struct platform_suspend_ops loongson_pm_ops = { 148 .valid = loongson_pm_valid_state, 149 .enter = loongson_pm_enter, 150 }; 151 152 static int __init loongson_pm_init(void) 153 { 154 suspend_set_ops(&loongson_pm_ops); 155 156 return 0; 157 } 158 arch_initcall(loongson_pm_init); 159