release/src-rt-6.x.4708/linux/linux-2.6.36/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         sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
  94         sgioc->reset = sgi_ioc_reset;
  95
  96         mod_timer(&blink_timer, jiffies + data);
  97 }
  98
  99 static void debounce(unsigned long data)
 100 {
 101         del_timer(&debounce_timer);
 102         if (sgint->istat1 & SGINT_ISTAT1_PWR) {
 103                 /* Interrupt still being sent. */
 104                 debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s  */
 105                 add_timer(&debounce_timer);
 106
 107                 sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
 108                                SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
 109                                SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;
 110
 111                 return;
 112         }
 113
 114         if (machine_state & MACHINE_PANICED)
 115                 sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
 116
 117         enable_irq(SGI_PANEL_IRQ);
 118 }
 119
 120 static inline void power_button(void)
 121 {
 122         if (machine_state & MACHINE_PANICED)
 123                 return;
 124
 125         if ((machine_state & MACHINE_SHUTTING_DOWN) ||
 126                         kill_cad_pid(SIGINT, 1)) {
 127                 /* No init process or button pressed twice.  */
 128                 sgi_machine_power_off();
 129         }
 130
 131         machine_state |= MACHINE_SHUTTING_DOWN;
 132         blink_timer.data = POWERDOWN_FREQ;
 133         blink_timeout(POWERDOWN_FREQ);
 134
 135         init_timer(&power_timer);
 136         power_timer.function = power_timeout;
 137         power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
 138         add_timer(&power_timer);
 139 }
 140
 141 static irqreturn_t panel_int(int irq, void *dev_id)
 142 {
 143         unsigned int buttons;
 144
 145         buttons = sgioc->panel;
 146         sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR;
 147
 148         if (sgint->istat1 & SGINT_ISTAT1_PWR) {
 149                 /* Wait until interrupt goes away */
 150                 disable_irq_nosync(SGI_PANEL_IRQ);
 151                 init_timer(&debounce_timer);
 152                 debounce_timer.function = debounce;
 153                 debounce_timer.expires = jiffies + 5;
 154                 add_timer(&debounce_timer);
 155         }
 156
 157         /* Power button was pressed
 158          * ioc.ps page 22: "The Panel Register is called Power Control by Full
 159          * House. Only lowest 2 bits are used. Guiness uses upper four bits
 160          * for volume control". This is not true, all bits are pulled high
 161          * on fullhouse */
 162         if (!(buttons & SGIOC_PANEL_POWERINTR))
 163                 power_button();
 164
 165         return IRQ_HANDLED;
 166 }
 167
 168 static int panic_event(struct notifier_block *this, unsigned long event,
 169                       void *ptr)
 170 {
 171         if (machine_state & MACHINE_PANICED)
 172                 return NOTIFY_DONE;
 173         machine_state |= MACHINE_PANICED;
 174
 175         blink_timer.data = PANIC_FREQ;
 176         blink_timeout(PANIC_FREQ);
 177
 178         return NOTIFY_DONE;
 179 }
 180
 181 static struct notifier_block panic_block = {
 182         .notifier_call  = panic_event,
 183 };
 184
 185 static int __init reboot_setup(void)
 186 {
 187         int res;
 188
 189         _machine_restart = sgi_machine_restart;
 190         _machine_halt = sgi_machine_halt;
 191         pm_power_off = sgi_machine_power_off;
 192
 193         res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
 194         if (res) {
 195                 printk(KERN_ERR "Allocation of front panel IRQ failed\n");
 196                 return res;
 197         }
 198
 199         init_timer(&blink_timer);
 200         blink_timer.function = blink_timeout;
 201         atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
 202
 203         return 0;
 204 }
 205
 206 subsys_initcall(reboot_setup);