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