arch/mips/sgi-ip22/ip22-reset.c

   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.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);