xref: /openbmc/linux/arch/mips/sgi-ip32/ip32-reset.c (revision a36954f5)
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/sched.h>
16 #include <linux/sched/signal.h>
17 #include <linux/notifier.h>
18 #include <linux/delay.h>
19 #include <linux/rtc/ds1685.h>
20 #include <linux/interrupt.h>
21 #include <linux/pm.h>
22 
23 #include <asm/addrspace.h>
24 #include <asm/irq.h>
25 #include <asm/reboot.h>
26 #include <asm/wbflush.h>
27 #include <asm/ip32/mace.h>
28 #include <asm/ip32/crime.h>
29 #include <asm/ip32/ip32_ints.h>
30 
31 #define POWERDOWN_TIMEOUT	120
32 /*
33  * Blink frequency during reboot grace period and when panicked.
34  */
35 #define POWERDOWN_FREQ		(HZ / 4)
36 #define PANIC_FREQ		(HZ / 8)
37 
38 extern struct platform_device ip32_rtc_device;
39 
40 static struct timer_list power_timer, blink_timer;
41 static int has_panicked, shutting_down;
42 
43 static __noreturn void ip32_poweroff(void *data)
44 {
45 	void (*poweroff_func)(struct platform_device *) =
46 		symbol_get(ds1685_rtc_poweroff);
47 
48 #ifdef CONFIG_MODULES
49 	/* If the first __symbol_get failed, our module wasn't loaded. */
50 	if (!poweroff_func) {
51 		request_module("rtc-ds1685");
52 		poweroff_func = symbol_get(ds1685_rtc_poweroff);
53 	}
54 #endif
55 
56 	if (!poweroff_func)
57 		pr_emerg("RTC not available for power-off.  Spinning forever ...\n");
58 	else {
59 		(*poweroff_func)((struct platform_device *)data);
60 		symbol_put(ds1685_rtc_poweroff);
61 	}
62 
63 	unreachable();
64 }
65 
66 static void ip32_machine_restart(char *cmd) __noreturn;
67 static void ip32_machine_restart(char *cmd)
68 {
69 	msleep(20);
70 	crime->control = CRIME_CONTROL_HARD_RESET;
71 	unreachable();
72 }
73 
74 static void blink_timeout(unsigned long data)
75 {
76 	unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
77 	mace->perif.ctrl.misc = led;
78 	mod_timer(&blink_timer, jiffies + data);
79 }
80 
81 static void ip32_machine_halt(void)
82 {
83 	ip32_poweroff(&ip32_rtc_device);
84 }
85 
86 static void power_timeout(unsigned long data)
87 {
88 	ip32_poweroff(&ip32_rtc_device);
89 }
90 
91 void ip32_prepare_poweroff(void)
92 {
93 	if (has_panicked)
94 		return;
95 
96 	if (shutting_down || kill_cad_pid(SIGINT, 1)) {
97 		/* No init process or button pressed twice.  */
98 		ip32_poweroff(&ip32_rtc_device);
99 	}
100 
101 	shutting_down = 1;
102 	blink_timer.data = POWERDOWN_FREQ;
103 	blink_timeout(POWERDOWN_FREQ);
104 
105 	init_timer(&power_timer);
106 	power_timer.function = power_timeout;
107 	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
108 	add_timer(&power_timer);
109 }
110 
111 static int panic_event(struct notifier_block *this, unsigned long event,
112 		       void *ptr)
113 {
114 	unsigned long led;
115 
116 	if (has_panicked)
117 		return NOTIFY_DONE;
118 	has_panicked = 1;
119 
120 	/* turn off the green LED */
121 	led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
122 	mace->perif.ctrl.misc = led;
123 
124 	blink_timer.data = PANIC_FREQ;
125 	blink_timeout(PANIC_FREQ);
126 
127 	return NOTIFY_DONE;
128 }
129 
130 static struct notifier_block panic_block = {
131 	.notifier_call = panic_event,
132 };
133 
134 static __init int ip32_reboot_setup(void)
135 {
136 	/* turn on the green led only */
137 	unsigned long led = mace->perif.ctrl.misc;
138 	led |= MACEISA_LED_RED;
139 	led &= ~MACEISA_LED_GREEN;
140 	mace->perif.ctrl.misc = led;
141 
142 	_machine_restart = ip32_machine_restart;
143 	_machine_halt = ip32_machine_halt;
144 	pm_power_off = ip32_machine_halt;
145 
146 	init_timer(&blink_timer);
147 	blink_timer.function = blink_timeout;
148 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
149 
150 	return 0;
151 }
152 
153 subsys_initcall(ip32_reboot_setup);
154