arch/mips/sgi-ip32/ip32-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) 2001 Keith M Wesolowski
   7  * Copyright (C) 2001 Paul Mundt
   8  * Copyright (C) 2003 Guido Guenther <agx@sigxcpu.org>
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/notifier.h>
  15 #include <linux/delay.h>
  16 #include <linux/ds17287rtc.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/pm.h>
  19
  20 #include <asm/addrspace.h>
  21 #include <asm/irq.h>
  22 #include <asm/reboot.h>
  23 #include <asm/wbflush.h>
  24 #include <asm/ip32/mace.h>
  25 #include <asm/ip32/crime.h>
  26 #include <asm/ip32/ip32_ints.h>
  27
  28 #define POWERDOWN_TIMEOUT       120
  29 /*
  30  * Blink frequency during reboot grace period and when panicked.
  31  */
  32 #define POWERDOWN_FREQ          (HZ / 4)
  33 #define PANIC_FREQ              (HZ / 8)
  34
  35 static struct timer_list power_timer, blink_timer, debounce_timer;
  36 static int has_panicked, shuting_down;
  37
  38 static void ip32_machine_restart(char *command) __attribute__((noreturn));
  39 static void ip32_machine_halt(void) __attribute__((noreturn));
  40 static void ip32_machine_power_off(void) __attribute__((noreturn));
  41
  42 static void ip32_machine_restart(char *cmd)
  43 {
  44         crime->control = CRIME_CONTROL_HARD_RESET;
  45         while (1);
  46 }
  47
  48 static inline void ip32_machine_halt(void)
  49 {
  50         ip32_machine_power_off();
  51 }
  52
  53 static void ip32_machine_power_off(void)
  54 {
  55         unsigned char reg_a, xctrl_a, xctrl_b;
  56
  57         disable_irq(MACEISA_RTC_IRQ);
  58         reg_a = CMOS_READ(RTC_REG_A);
  59
  60         /* setup for kickstart & wake-up (DS12287 Ref. Man. p. 19) */
  61         reg_a &= ~DS_REGA_DV2;
  62         reg_a |= DS_REGA_DV1;
  63
  64         CMOS_WRITE(reg_a | DS_REGA_DV0, RTC_REG_A);
  65         wbflush();
  66         xctrl_b = CMOS_READ(DS_B1_XCTRL4B)
  67                    | DS_XCTRL4B_ABE | DS_XCTRL4B_KFE;
  68         CMOS_WRITE(xctrl_b, DS_B1_XCTRL4B);
  69         xctrl_a = CMOS_READ(DS_B1_XCTRL4A) & ~DS_XCTRL4A_IFS;
  70         CMOS_WRITE(xctrl_a, DS_B1_XCTRL4A);
  71         wbflush();
  72         /* adios amigos... */
  73         CMOS_WRITE(xctrl_a | DS_XCTRL4A_PAB, DS_B1_XCTRL4A);
  74         CMOS_WRITE(reg_a, RTC_REG_A);
  75         wbflush();
  76         while (1);
  77 }
  78
  79 static void power_timeout(unsigned long data)
  80 {
  81         ip32_machine_power_off();
  82 }
  83
  84 static void blink_timeout(unsigned long data)
  85 {
  86         unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
  87         mace->perif.ctrl.misc = led;
  88         mod_timer(&blink_timer, jiffies + data);
  89 }
  90
  91 static void debounce(unsigned long data)
  92 {
  93         unsigned char reg_a, reg_c, xctrl_a;
  94
  95         reg_c = CMOS_READ(RTC_INTR_FLAGS);
  96         reg_a = CMOS_READ(RTC_REG_A);
  97         CMOS_WRITE(reg_a | DS_REGA_DV0, RTC_REG_A);
  98         wbflush();
  99         xctrl_a = CMOS_READ(DS_B1_XCTRL4A);
 100         if ((xctrl_a & DS_XCTRL4A_IFS) || (reg_c & RTC_IRQF )) {
 101                 /* Interrupt still being sent. */
 102                 debounce_timer.expires = jiffies + 50;
 103                 add_timer(&debounce_timer);
 104
 105                 /* clear interrupt source */
 106                 CMOS_WRITE(xctrl_a & ~DS_XCTRL4A_IFS, DS_B1_XCTRL4A);
 107                 CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
 108                 return;
 109         }
 110         CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
 111
 112         if (has_panicked)
 113                 ip32_machine_restart(NULL);
 114
 115         enable_irq(MACEISA_RTC_IRQ);
 116 }
 117
 118 static inline void ip32_power_button(void)
 119 {
 120         if (has_panicked)
 121                 return;
 122
 123         if (shuting_down || kill_cad_pid(SIGINT, 1)) {
 124                 /* No init process or button pressed twice.  */
 125                 ip32_machine_power_off();
 126         }
 127
 128         shuting_down = 1;
 129         blink_timer.data = POWERDOWN_FREQ;
 130         blink_timeout(POWERDOWN_FREQ);
 131
 132         init_timer(&power_timer);
 133         power_timer.function = power_timeout;
 134         power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
 135         add_timer(&power_timer);
 136 }
 137
 138 static irqreturn_t ip32_rtc_int(int irq, void *dev_id)
 139 {
 140         unsigned char reg_c;
 141
 142         reg_c = CMOS_READ(RTC_INTR_FLAGS);
 143         if (!(reg_c & RTC_IRQF)) {
 144                 printk(KERN_WARNING
 145                         "%s: RTC IRQ without RTC_IRQF\n", __func__);
 146         }
 147         /* Wait until interrupt goes away */
 148         disable_irq_nosync(MACEISA_RTC_IRQ);
 149         init_timer(&debounce_timer);
 150         debounce_timer.function = debounce;
 151         debounce_timer.expires = jiffies + 50;
 152         add_timer(&debounce_timer);
 153
 154         printk(KERN_DEBUG "Power button pressed\n");
 155         ip32_power_button();
 156         return IRQ_HANDLED;
 157 }
 158
 159 static int panic_event(struct notifier_block *this, unsigned long event,
 160                        void *ptr)
 161 {
 162         unsigned long led;
 163
 164         if (has_panicked)
 165                 return NOTIFY_DONE;
 166         has_panicked = 1;
 167
 168         /* turn off the green LED */
 169         led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
 170         mace->perif.ctrl.misc = led;
 171
 172         blink_timer.data = PANIC_FREQ;
 173         blink_timeout(PANIC_FREQ);
 174
 175         return NOTIFY_DONE;
 176 }
 177
 178 static struct notifier_block panic_block = {
 179         .notifier_call = panic_event,
 180 };
 181
 182 static __init int ip32_reboot_setup(void)
 183 {
 184         /* turn on the green led only */
 185         unsigned long led = mace->perif.ctrl.misc;
 186         led |= MACEISA_LED_RED;
 187         led &= ~MACEISA_LED_GREEN;
 188         mace->perif.ctrl.misc = led;
 189
 190         _machine_restart = ip32_machine_restart;
 191         _machine_halt = ip32_machine_halt;
 192         pm_power_off = ip32_machine_power_off;
 193
 194         init_timer(&blink_timer);
 195         blink_timer.function = blink_timeout;
 196         atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
 197
 198         if (request_irq(MACEISA_RTC_IRQ, ip32_rtc_int, 0, "rtc", NULL))
 199                 panic("Can't allocate MACEISA RTC IRQ");
 200
 201         return 0;
 202 }
 203
 204 subsys_initcall(ip32_reboot_setup);