xref: /linux/arch/mips/sgi-ip32/ip32-reset.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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/sched.h>
15 #include <linux/notifier.h>
16 #include <linux/delay.h>
17 #include <linux/ds17287rtc.h>
18 #include <linux/interrupt.h>
19 #include <linux/pm.h>
20 
21 #include <asm/addrspace.h>
22 #include <asm/irq.h>
23 #include <asm/reboot.h>
24 #include <asm/wbflush.h>
25 #include <asm/ip32/mace.h>
26 #include <asm/ip32/crime.h>
27 #include <asm/ip32/ip32_ints.h>
28 
29 #define POWERDOWN_TIMEOUT	120
30 /*
31  * Blink frequency during reboot grace period and when panicked.
32  */
33 #define POWERDOWN_FREQ		(HZ / 4)
34 #define PANIC_FREQ		(HZ / 8)
35 
36 static struct timer_list power_timer, blink_timer, debounce_timer;
37 static int has_panicked, shuting_down;
38 
39 static void ip32_machine_restart(char *command) __noreturn;
40 static void ip32_machine_halt(void) __noreturn;
41 static void ip32_machine_power_off(void) __noreturn;
42 
43 static void ip32_machine_restart(char *cmd)
44 {
45 	crime->control = CRIME_CONTROL_HARD_RESET;
46 	while (1);
47 }
48 
49 static inline void ip32_machine_halt(void)
50 {
51 	ip32_machine_power_off();
52 }
53 
54 static void ip32_machine_power_off(void)
55 {
56 	unsigned char reg_a, xctrl_a, xctrl_b;
57 
58 	disable_irq(MACEISA_RTC_IRQ);
59 	reg_a = CMOS_READ(RTC_REG_A);
60 
61 	/* setup for kickstart & wake-up (DS12287 Ref. Man. p. 19) */
62 	reg_a &= ~DS_REGA_DV2;
63 	reg_a |= DS_REGA_DV1;
64 
65 	CMOS_WRITE(reg_a | DS_REGA_DV0, RTC_REG_A);
66 	wbflush();
67 	xctrl_b = CMOS_READ(DS_B1_XCTRL4B)
68 		   | DS_XCTRL4B_ABE | DS_XCTRL4B_KFE;
69 	CMOS_WRITE(xctrl_b, DS_B1_XCTRL4B);
70 	xctrl_a = CMOS_READ(DS_B1_XCTRL4A) & ~DS_XCTRL4A_IFS;
71 	CMOS_WRITE(xctrl_a, DS_B1_XCTRL4A);
72 	wbflush();
73 	/* adios amigos... */
74 	CMOS_WRITE(xctrl_a | DS_XCTRL4A_PAB, DS_B1_XCTRL4A);
75 	CMOS_WRITE(reg_a, RTC_REG_A);
76 	wbflush();
77 	while (1);
78 }
79 
80 static void power_timeout(unsigned long data)
81 {
82 	ip32_machine_power_off();
83 }
84 
85 static void blink_timeout(unsigned long data)
86 {
87 	unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
88 	mace->perif.ctrl.misc = led;
89 	mod_timer(&blink_timer, jiffies + data);
90 }
91 
92 static void debounce(unsigned long data)
93 {
94 	unsigned char reg_a, reg_c, xctrl_a;
95 
96 	reg_c = CMOS_READ(RTC_INTR_FLAGS);
97 	reg_a = CMOS_READ(RTC_REG_A);
98 	CMOS_WRITE(reg_a | DS_REGA_DV0, RTC_REG_A);
99 	wbflush();
100 	xctrl_a = CMOS_READ(DS_B1_XCTRL4A);
101 	if ((xctrl_a & DS_XCTRL4A_IFS) || (reg_c & RTC_IRQF )) {
102 		/* Interrupt still being sent. */
103 		debounce_timer.expires = jiffies + 50;
104 		add_timer(&debounce_timer);
105 
106 		/* clear interrupt source */
107 		CMOS_WRITE(xctrl_a & ~DS_XCTRL4A_IFS, DS_B1_XCTRL4A);
108 		CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
109 		return;
110 	}
111 	CMOS_WRITE(reg_a & ~DS_REGA_DV0, RTC_REG_A);
112 
113 	if (has_panicked)
114 		ip32_machine_restart(NULL);
115 
116 	enable_irq(MACEISA_RTC_IRQ);
117 }
118 
119 static inline void ip32_power_button(void)
120 {
121 	if (has_panicked)
122 		return;
123 
124 	if (shuting_down || kill_cad_pid(SIGINT, 1)) {
125 		/* No init process or button pressed twice.  */
126 		ip32_machine_power_off();
127 	}
128 
129 	shuting_down = 1;
130 	blink_timer.data = POWERDOWN_FREQ;
131 	blink_timeout(POWERDOWN_FREQ);
132 
133 	init_timer(&power_timer);
134 	power_timer.function = power_timeout;
135 	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
136 	add_timer(&power_timer);
137 }
138 
139 static irqreturn_t ip32_rtc_int(int irq, void *dev_id)
140 {
141 	unsigned char reg_c;
142 
143 	reg_c = CMOS_READ(RTC_INTR_FLAGS);
144 	if (!(reg_c & RTC_IRQF)) {
145 		printk(KERN_WARNING
146 			"%s: RTC IRQ without RTC_IRQF\n", __func__);
147 	}
148 	/* Wait until interrupt goes away */
149 	disable_irq_nosync(MACEISA_RTC_IRQ);
150 	init_timer(&debounce_timer);
151 	debounce_timer.function = debounce;
152 	debounce_timer.expires = jiffies + 50;
153 	add_timer(&debounce_timer);
154 
155 	printk(KERN_DEBUG "Power button pressed\n");
156 	ip32_power_button();
157 	return IRQ_HANDLED;
158 }
159 
160 static int panic_event(struct notifier_block *this, unsigned long event,
161 		       void *ptr)
162 {
163 	unsigned long led;
164 
165 	if (has_panicked)
166 		return NOTIFY_DONE;
167 	has_panicked = 1;
168 
169 	/* turn off the green LED */
170 	led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
171 	mace->perif.ctrl.misc = led;
172 
173 	blink_timer.data = PANIC_FREQ;
174 	blink_timeout(PANIC_FREQ);
175 
176 	return NOTIFY_DONE;
177 }
178 
179 static struct notifier_block panic_block = {
180 	.notifier_call = panic_event,
181 };
182 
183 static __init int ip32_reboot_setup(void)
184 {
185 	/* turn on the green led only */
186 	unsigned long led = mace->perif.ctrl.misc;
187 	led |= MACEISA_LED_RED;
188 	led &= ~MACEISA_LED_GREEN;
189 	mace->perif.ctrl.misc = led;
190 
191 	_machine_restart = ip32_machine_restart;
192 	_machine_halt = ip32_machine_halt;
193 	pm_power_off = ip32_machine_power_off;
194 
195 	init_timer(&blink_timer);
196 	blink_timer.function = blink_timeout;
197 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
198 
199 	if (request_irq(MACEISA_RTC_IRQ, ip32_rtc_int, 0, "rtc", NULL))
200 		panic("Can't allocate MACEISA RTC IRQ");
201 
202 	return 0;
203 }
204 
205 subsys_initcall(ip32_reboot_setup);
206