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/compiler.h>
 12#include <linux/init.h>
 13#include <linux/kernel.h>
 14#include <linux/module.h>
 15#include <linux/panic_notifier.h>
 16#include <linux/sched.h>
 17#include <linux/sched/signal.h>
 18#include <linux/notifier.h>
 19#include <linux/delay.h>
 20#include <linux/rtc/ds1685.h>
 21#include <linux/interrupt.h>
 22#include <linux/pm.h>
 23
 24#include <asm/addrspace.h>
 25#include <asm/irq.h>
 26#include <asm/reboot.h>
 27#include <asm/wbflush.h>
 28#include <asm/ip32/mace.h>
 29#include <asm/ip32/crime.h>
 30#include <asm/ip32/ip32_ints.h>
 31
 32#include "ip32-common.h"
 33
 34#define POWERDOWN_TIMEOUT	120
 35/*
 36 * Blink frequency during reboot grace period and when panicked.
 37 */
 38#define POWERDOWN_FREQ		(HZ / 4)
 39#define PANIC_FREQ		(HZ / 8)
 40
 41extern struct platform_device ip32_rtc_device;
 42
 43static struct timer_list power_timer, blink_timer;
 44static unsigned long blink_timer_timeout;
 45static int has_panicked, shutting_down;
 46
 47static __noreturn void ip32_poweroff(void *data)
 48{
 49	void (*poweroff_func)(struct platform_device *) =
 50		symbol_get(ds1685_rtc_poweroff);
 51
 52#ifdef CONFIG_MODULES
 53	/* If the first __symbol_get failed, our module wasn't loaded. */
 54	if (!poweroff_func) {
 55		request_module("rtc-ds1685");
 56		poweroff_func = symbol_get(ds1685_rtc_poweroff);
 57	}
 58#endif
 59
 60	if (!poweroff_func)
 61		pr_emerg("RTC not available for power-off.  Spinning forever ...\n");
 62	else {
 63		(*poweroff_func)((struct platform_device *)data);
 64		symbol_put(ds1685_rtc_poweroff);
 65	}
 66
 67	unreachable();
 68}
 69
 70static void ip32_machine_restart(char *cmd) __noreturn;
 71static void ip32_machine_restart(char *cmd)
 72{
 73	msleep(20);
 74	crime->control = CRIME_CONTROL_HARD_RESET;
 75	unreachable();
 76}
 77
 78static void blink_timeout(struct timer_list *unused)
 79{
 80	unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
 81	mace->perif.ctrl.misc = led;
 82	mod_timer(&blink_timer, jiffies + blink_timer_timeout);
 83}
 84
 85static void ip32_machine_halt(void)
 86{
 87	ip32_poweroff(&ip32_rtc_device);
 88}
 89
 90static void power_timeout(struct timer_list *unused)
 91{
 92	ip32_poweroff(&ip32_rtc_device);
 93}
 94
 95void ip32_prepare_poweroff(void)
 96{
 97	if (has_panicked)
 98		return;
 99
100	if (shutting_down || kill_cad_pid(SIGINT, 1)) {
101		/* No init process or button pressed twice.  */
102		ip32_poweroff(&ip32_rtc_device);
103	}
104
105	shutting_down = 1;
106	blink_timer_timeout = POWERDOWN_FREQ;
107	blink_timeout(&blink_timer);
108
109	timer_setup(&power_timer, power_timeout, 0);
110	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
111	add_timer(&power_timer);
112}
113
114static int panic_event(struct notifier_block *this, unsigned long event,
115		       void *ptr)
116{
117	unsigned long led;
118
119	if (has_panicked)
120		return NOTIFY_DONE;
121	has_panicked = 1;
122
123	/* turn off the green LED */
124	led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
125	mace->perif.ctrl.misc = led;
126
127	blink_timer_timeout = PANIC_FREQ;
128	blink_timeout(&blink_timer);
129
130	return NOTIFY_DONE;
131}
132
133static struct notifier_block panic_block = {
134	.notifier_call = panic_event,
135};
136
137static __init int ip32_reboot_setup(void)
138{
139	/* turn on the green led only */
140	unsigned long led = mace->perif.ctrl.misc;
141	led |= MACEISA_LED_RED;
142	led &= ~MACEISA_LED_GREEN;
143	mace->perif.ctrl.misc = led;
144
145	_machine_restart = ip32_machine_restart;
146	_machine_halt = ip32_machine_halt;
147	pm_power_off = ip32_machine_halt;
148
149	timer_setup(&blink_timer, blink_timeout, 0);
150	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
151
152	return 0;
153}
154
155subsys_initcall(ip32_reboot_setup);