arch/mips/loongson2ef/common/pm.c

   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);