xref: /openbmc/linux/arch/mips/sgi-ip32/ip32-reset.c (revision 3cf3cdea)
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 #define POWERDOWN_TIMEOUT	120
33 /*
34  * Blink frequency during reboot grace period and when panicked.
35  */
36 #define POWERDOWN_FREQ		(HZ / 4)
37 #define PANIC_FREQ		(HZ / 8)
38 
39 extern struct platform_device ip32_rtc_device;
40 
41 static struct timer_list power_timer, blink_timer;
42 static unsigned long blink_timer_timeout;
43 static int has_panicked, shutting_down;
44 
45 static __noreturn void ip32_poweroff(void *data)
46 {
47 	void (*poweroff_func)(struct platform_device *) =
48 		symbol_get(ds1685_rtc_poweroff);
49 
50 #ifdef CONFIG_MODULES
51 	/* If the first __symbol_get failed, our module wasn't loaded. */
52 	if (!poweroff_func) {
53 		request_module("rtc-ds1685");
54 		poweroff_func = symbol_get(ds1685_rtc_poweroff);
55 	}
56 #endif
57 
58 	if (!poweroff_func)
59 		pr_emerg("RTC not available for power-off.  Spinning forever ...\n");
60 	else {
61 		(*poweroff_func)((struct platform_device *)data);
62 		symbol_put(ds1685_rtc_poweroff);
63 	}
64 
65 	unreachable();
66 }
67 
68 static void ip32_machine_restart(char *cmd) __noreturn;
69 static void ip32_machine_restart(char *cmd)
70 {
71 	msleep(20);
72 	crime->control = CRIME_CONTROL_HARD_RESET;
73 	unreachable();
74 }
75 
76 static void blink_timeout(struct timer_list *unused)
77 {
78 	unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
79 	mace->perif.ctrl.misc = led;
80 	mod_timer(&blink_timer, jiffies + blink_timer_timeout);
81 }
82 
83 static void ip32_machine_halt(void)
84 {
85 	ip32_poweroff(&ip32_rtc_device);
86 }
87 
88 static void power_timeout(struct timer_list *unused)
89 {
90 	ip32_poweroff(&ip32_rtc_device);
91 }
92 
93 void ip32_prepare_poweroff(void)
94 {
95 	if (has_panicked)
96 		return;
97 
98 	if (shutting_down || kill_cad_pid(SIGINT, 1)) {
99 		/* No init process or button pressed twice.  */
100 		ip32_poweroff(&ip32_rtc_device);
101 	}
102 
103 	shutting_down = 1;
104 	blink_timer_timeout = POWERDOWN_FREQ;
105 	blink_timeout(&blink_timer);
106 
107 	timer_setup(&power_timer, power_timeout, 0);
108 	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
109 	add_timer(&power_timer);
110 }
111 
112 static int panic_event(struct notifier_block *this, unsigned long event,
113 		       void *ptr)
114 {
115 	unsigned long led;
116 
117 	if (has_panicked)
118 		return NOTIFY_DONE;
119 	has_panicked = 1;
120 
121 	/* turn off the green LED */
122 	led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
123 	mace->perif.ctrl.misc = led;
124 
125 	blink_timer_timeout = PANIC_FREQ;
126 	blink_timeout(&blink_timer);
127 
128 	return NOTIFY_DONE;
129 }
130 
131 static struct notifier_block panic_block = {
132 	.notifier_call = panic_event,
133 };
134 
135 static __init int ip32_reboot_setup(void)
136 {
137 	/* turn on the green led only */
138 	unsigned long led = mace->perif.ctrl.misc;
139 	led |= MACEISA_LED_RED;
140 	led &= ~MACEISA_LED_GREEN;
141 	mace->perif.ctrl.misc = led;
142 
143 	_machine_restart = ip32_machine_restart;
144 	_machine_halt = ip32_machine_halt;
145 	pm_power_off = ip32_machine_halt;
146 
147 	timer_setup(&blink_timer, blink_timeout, 0);
148 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
149 
150 	return 0;
151 }
152 
153 subsys_initcall(ip32_reboot_setup);
154