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