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
  19 #include <asm/addrspace.h>
  20 #include <asm/irq.h>
  21 #include <asm/reboot.h>
  22 #include <asm/system.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 paniced.
  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_paniced, 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         volatile 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         volatile unsigned char reg_a, reg_c, xctrl_a;
  94
  95         reg_c = CMOS_READ(RTC_INTR_FLAGS);
  96         CMOS_WRITE(reg_a | DS_REGA_DV0, RTC_REG_A);
  97         wbflush();
  98         xctrl_a = CMOS_READ(DS_B1_XCTRL4A);
  99         if ((xctrl_a & DS_XCTRL4A_IFS) || (reg_c & RTC_IRQF )) {
 100                 /* Interrupt still being sent. */
 101                 debounce_timer.expires = jiffies + 50;
 102                 add_timer(&debounce_timer);
 103
 104                 /* clear interrupt source */
 105                 CMOS_WRITE(xctrl_a & ~DS_XCTRL4A_IFS, DS_B1_XCTRL4A);
 106                 CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
 107                 return;
 108         }
 109         CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
 110
 111         if (has_paniced)
 112                 ip32_machine_restart(NULL);
 113
 114         enable_irq(MACEISA_RTC_IRQ);
 115 }
 116
 117 static inline void ip32_power_button(void)
 118 {
 119         if (has_paniced)
 120                 return;
 121
 122         if (shuting_down || kill_proc(1, SIGINT, 1)) {
 123                 /* No init process or button pressed twice.  */
 124                 ip32_machine_power_off();
 125         }
 126
 127         shuting_down = 1;
 128         blink_timer.data = POWERDOWN_FREQ;
 129         blink_timeout(POWERDOWN_FREQ);
 130
 131         init_timer(&power_timer);
 132         power_timer.function = power_timeout;
 133         power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
 134         add_timer(&power_timer);
 135 }
 136
 137 static irqreturn_t ip32_rtc_int(int irq, void *dev_id, struct pt_regs *regs)
 138 {
 139         volatile unsigned char reg_c;
 140
 141         reg_c = CMOS_READ(RTC_INTR_FLAGS);
 142         if (!(reg_c & RTC_IRQF)) {
 143                 printk(KERN_WARNING
 144                         "%s: RTC IRQ without RTC_IRQF\n", __FUNCTION__);
 145         }
 146         /* Wait until interrupt goes away */
 147         disable_irq(MACEISA_RTC_IRQ);
 148         init_timer(&debounce_timer);
 149         debounce_timer.function = debounce;
 150         debounce_timer.expires = jiffies + 50;
 151         add_timer(&debounce_timer);
 152
 153         printk(KERN_DEBUG "Power button pressed\n");
 154         ip32_power_button();
 155         return IRQ_HANDLED;
 156 }
 157
 158 static int panic_event(struct notifier_block *this, unsigned long event,
 159                        void *ptr)
 160 {
 161         unsigned long led;
 162
 163         if (has_paniced)
 164                 return NOTIFY_DONE;
 165         has_paniced = 1;
 166
 167         /* turn off the green LED */
 168         led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
 169         mace->perif.ctrl.misc = led;
 170
 171         blink_timer.data = PANIC_FREQ;
 172         blink_timeout(PANIC_FREQ);
 173
 174         return NOTIFY_DONE;
 175 }
 176
 177 static struct notifier_block panic_block = {
 178         .notifier_call = panic_event,
 179 };
 180
 181 static __init int ip32_reboot_setup(void)
 182 {
 183         /* turn on the green led only */
 184         unsigned long led = mace->perif.ctrl.misc;
 185         led |= MACEISA_LED_RED;
 186         led &= ~MACEISA_LED_GREEN;
 187         mace->perif.ctrl.misc = led;
 188
 189         _machine_restart = ip32_machine_restart;
 190         _machine_halt = ip32_machine_halt;
 191         _machine_power_off = ip32_machine_power_off;
 192
 193         init_timer(&blink_timer);
 194         blink_timer.function = blink_timeout;
 195         notifier_chain_register(&panic_notifier_list, &panic_block);
 196
 197         request_irq(MACEISA_RTC_IRQ, ip32_rtc_int, 0, "rtc", NULL);
 198
 199         return 0;
 200 }
 201
 202 subsys_initcall(ip32_reboot_setup);