1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1997, 1998, 2001, 03, 05, 06 by Ralf Baechle 7 */ 8 #include <linux/linkage.h> 9 #include <linux/init.h> 10 #include <linux/rtc/ds1286.h> 11 #include <linux/interrupt.h> 12 #include <linux/kernel.h> 13 #include <linux/sched/signal.h> 14 #include <linux/notifier.h> 15 #include <linux/pm.h> 16 #include <linux/timer.h> 17 18 #include <asm/io.h> 19 #include <asm/irq.h> 20 #include <asm/reboot.h> 21 #include <asm/sgialib.h> 22 #include <asm/sgi/ioc.h> 23 #include <asm/sgi/hpc3.h> 24 #include <asm/sgi/mc.h> 25 #include <asm/sgi/ip22.h> 26 27 /* 28 * Just powerdown if init hasn't done after POWERDOWN_TIMEOUT seconds. 29 * I'm not sure if this feature is a good idea, for now it's here just to 30 * make the power button make behave just like under IRIX. 31 */ 32 #define POWERDOWN_TIMEOUT 120 33 34 /* 35 * Blink frequency during reboot grace period and when panicked. 36 */ 37 #define POWERDOWN_FREQ (HZ / 4) 38 #define PANIC_FREQ (HZ / 8) 39 40 static struct timer_list power_timer, blink_timer, debounce_timer; 41 42 #define MACHINE_PANICED 1 43 #define MACHINE_SHUTTING_DOWN 2 44 45 static int machine_state; 46 47 static void __noreturn sgi_machine_power_off(void) 48 { 49 unsigned int tmp; 50 51 local_irq_disable(); 52 53 /* Disable watchdog */ 54 tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff; 55 hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM; 56 hpc3c0->rtcregs[RTC_WSEC] = 0; 57 hpc3c0->rtcregs[RTC_WHSEC] = 0; 58 59 while (1) { 60 sgioc->panel = ~SGIOC_PANEL_POWERON; 61 /* Good bye cruel world ... */ 62 63 /* If we're still running, we probably got sent an alarm 64 interrupt. Read the flag to clear it. */ 65 tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM]; 66 } 67 } 68 69 static void __noreturn sgi_machine_restart(char *command) 70 { 71 if (machine_state & MACHINE_SHUTTING_DOWN) 72 sgi_machine_power_off(); 73 sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT; 74 while (1); 75 } 76 77 static void __noreturn sgi_machine_halt(void) 78 { 79 if (machine_state & MACHINE_SHUTTING_DOWN) 80 sgi_machine_power_off(); 81 ArcEnterInteractiveMode(); 82 } 83 84 static void power_timeout(unsigned long data) 85 { 86 sgi_machine_power_off(); 87 } 88 89 static void blink_timeout(unsigned long data) 90 { 91 /* XXX fix this for fullhouse */ 92 sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF); 93 sgioc->reset = sgi_ioc_reset; 94 95 mod_timer(&blink_timer, jiffies + data); 96 } 97 98 static void debounce(unsigned long data) 99 { 100 del_timer(&debounce_timer); 101 if (sgint->istat1 & SGINT_ISTAT1_PWR) { 102 /* Interrupt still being sent. */ 103 debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s */ 104 add_timer(&debounce_timer); 105 106 sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR | 107 SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD | 108 SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD; 109 110 return; 111 } 112 113 if (machine_state & MACHINE_PANICED) 114 sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT; 115 116 enable_irq(SGI_PANEL_IRQ); 117 } 118 119 static inline void power_button(void) 120 { 121 if (machine_state & MACHINE_PANICED) 122 return; 123 124 if ((machine_state & MACHINE_SHUTTING_DOWN) || 125 kill_cad_pid(SIGINT, 1)) { 126 /* No init process or button pressed twice. */ 127 sgi_machine_power_off(); 128 } 129 130 machine_state |= MACHINE_SHUTTING_DOWN; 131 blink_timer.data = POWERDOWN_FREQ; 132 blink_timeout(POWERDOWN_FREQ); 133 134 init_timer(&power_timer); 135 power_timer.function = power_timeout; 136 power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ; 137 add_timer(&power_timer); 138 } 139 140 static irqreturn_t panel_int(int irq, void *dev_id) 141 { 142 unsigned int buttons; 143 144 buttons = sgioc->panel; 145 sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR; 146 147 if (sgint->istat1 & SGINT_ISTAT1_PWR) { 148 /* Wait until interrupt goes away */ 149 disable_irq_nosync(SGI_PANEL_IRQ); 150 init_timer(&debounce_timer); 151 debounce_timer.function = debounce; 152 debounce_timer.expires = jiffies + 5; 153 add_timer(&debounce_timer); 154 } 155 156 /* Power button was pressed 157 * ioc.ps page 22: "The Panel Register is called Power Control by Full 158 * House. Only lowest 2 bits are used. Guiness uses upper four bits 159 * for volume control". This is not true, all bits are pulled high 160 * on fullhouse */ 161 if (!(buttons & SGIOC_PANEL_POWERINTR)) 162 power_button(); 163 164 return IRQ_HANDLED; 165 } 166 167 static int panic_event(struct notifier_block *this, unsigned long event, 168 void *ptr) 169 { 170 if (machine_state & MACHINE_PANICED) 171 return NOTIFY_DONE; 172 machine_state |= MACHINE_PANICED; 173 174 blink_timer.data = PANIC_FREQ; 175 blink_timeout(PANIC_FREQ); 176 177 return NOTIFY_DONE; 178 } 179 180 static struct notifier_block panic_block = { 181 .notifier_call = panic_event, 182 }; 183 184 static int __init reboot_setup(void) 185 { 186 int res; 187 188 _machine_restart = sgi_machine_restart; 189 _machine_halt = sgi_machine_halt; 190 pm_power_off = sgi_machine_power_off; 191 192 res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL); 193 if (res) { 194 printk(KERN_ERR "Allocation of front panel IRQ failed\n"); 195 return res; 196 } 197 198 init_timer(&blink_timer); 199 blink_timer.function = blink_timeout; 200 atomic_notifier_chain_register(&panic_notifier_list, &panic_block); 201 202 return 0; 203 } 204 205 subsys_initcall(reboot_setup); 206