xref: /openbmc/linux/arch/mips/sgi-ip32/ip32-reset.c (revision bc5aa3a0)
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/notifier.h>
17 #include <linux/delay.h>
18 #include <linux/rtc/ds1685.h>
19 #include <linux/interrupt.h>
20 #include <linux/pm.h>
21 
22 #include <asm/addrspace.h>
23 #include <asm/irq.h>
24 #include <asm/reboot.h>
25 #include <asm/wbflush.h>
26 #include <asm/ip32/mace.h>
27 #include <asm/ip32/crime.h>
28 #include <asm/ip32/ip32_ints.h>
29 
30 #define POWERDOWN_TIMEOUT	120
31 /*
32  * Blink frequency during reboot grace period and when panicked.
33  */
34 #define POWERDOWN_FREQ		(HZ / 4)
35 #define PANIC_FREQ		(HZ / 8)
36 
37 extern struct platform_device ip32_rtc_device;
38 
39 static struct timer_list power_timer, blink_timer;
40 static int has_panicked, shutting_down;
41 
42 static __noreturn void ip32_poweroff(void *data)
43 {
44 	void (*poweroff_func)(struct platform_device *) =
45 		symbol_get(ds1685_rtc_poweroff);
46 
47 #ifdef CONFIG_MODULES
48 	/* If the first __symbol_get failed, our module wasn't loaded. */
49 	if (!poweroff_func) {
50 		request_module("rtc-ds1685");
51 		poweroff_func = symbol_get(ds1685_rtc_poweroff);
52 	}
53 #endif
54 
55 	if (!poweroff_func)
56 		pr_emerg("RTC not available for power-off.  Spinning forever ...\n");
57 	else {
58 		(*poweroff_func)((struct platform_device *)data);
59 		symbol_put(ds1685_rtc_poweroff);
60 	}
61 
62 	unreachable();
63 }
64 
65 static void ip32_machine_restart(char *cmd) __noreturn;
66 static void ip32_machine_restart(char *cmd)
67 {
68 	msleep(20);
69 	crime->control = CRIME_CONTROL_HARD_RESET;
70 	unreachable();
71 }
72 
73 static void blink_timeout(unsigned long data)
74 {
75 	unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
76 	mace->perif.ctrl.misc = led;
77 	mod_timer(&blink_timer, jiffies + data);
78 }
79 
80 static void ip32_machine_halt(void)
81 {
82 	ip32_poweroff(&ip32_rtc_device);
83 }
84 
85 static void power_timeout(unsigned long data)
86 {
87 	ip32_poweroff(&ip32_rtc_device);
88 }
89 
90 void ip32_prepare_poweroff(void)
91 {
92 	if (has_panicked)
93 		return;
94 
95 	if (shutting_down || kill_cad_pid(SIGINT, 1)) {
96 		/* No init process or button pressed twice.  */
97 		ip32_poweroff(&ip32_rtc_device);
98 	}
99 
100 	shutting_down = 1;
101 	blink_timer.data = POWERDOWN_FREQ;
102 	blink_timeout(POWERDOWN_FREQ);
103 
104 	init_timer(&power_timer);
105 	power_timer.function = power_timeout;
106 	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
107 	add_timer(&power_timer);
108 }
109 
110 static int panic_event(struct notifier_block *this, unsigned long event,
111 		       void *ptr)
112 {
113 	unsigned long led;
114 
115 	if (has_panicked)
116 		return NOTIFY_DONE;
117 	has_panicked = 1;
118 
119 	/* turn off the green LED */
120 	led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
121 	mace->perif.ctrl.misc = led;
122 
123 	blink_timer.data = PANIC_FREQ;
124 	blink_timeout(PANIC_FREQ);
125 
126 	return NOTIFY_DONE;
127 }
128 
129 static struct notifier_block panic_block = {
130 	.notifier_call = panic_event,
131 };
132 
133 static __init int ip32_reboot_setup(void)
134 {
135 	/* turn on the green led only */
136 	unsigned long led = mace->perif.ctrl.misc;
137 	led |= MACEISA_LED_RED;
138 	led &= ~MACEISA_LED_GREEN;
139 	mace->perif.ctrl.misc = led;
140 
141 	_machine_restart = ip32_machine_restart;
142 	_machine_halt = ip32_machine_halt;
143 	pm_power_off = ip32_machine_halt;
144 
145 	init_timer(&blink_timer);
146 	blink_timer.function = blink_timeout;
147 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
148 
149 	return 0;
150 }
151 
152 subsys_initcall(ip32_reboot_setup);
153