xref: /openbmc/linux/arch/mips/sgi-ip22/ip22-reset.c (revision 5d0e4d78)
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) 1997, 1998, 2001, 03, 05, 06 by Ralf Baechle
7  */
8 #include <linux/linkage.h>
9 #include <linux/init.h>
10 #include <linux/rtc/ds1286.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/sched/signal.h>
14 #include <linux/notifier.h>
15 #include <linux/pm.h>
16 #include <linux/timer.h>
17 
18 #include <asm/io.h>
19 #include <asm/irq.h>
20 #include <asm/reboot.h>
21 #include <asm/sgialib.h>
22 #include <asm/sgi/ioc.h>
23 #include <asm/sgi/hpc3.h>
24 #include <asm/sgi/mc.h>
25 #include <asm/sgi/ip22.h>
26 
27 /*
28  * Just powerdown if init hasn't done after POWERDOWN_TIMEOUT seconds.
29  * I'm not sure if this feature is a good idea, for now it's here just to
30  * make the power button make behave just like under IRIX.
31  */
32 #define POWERDOWN_TIMEOUT	120
33 
34 /*
35  * Blink frequency during reboot grace period and when panicked.
36  */
37 #define POWERDOWN_FREQ		(HZ / 4)
38 #define PANIC_FREQ		(HZ / 8)
39 
40 static struct timer_list power_timer, blink_timer, debounce_timer;
41 
42 #define MACHINE_PANICED		1
43 #define MACHINE_SHUTTING_DOWN	2
44 
45 static int machine_state;
46 
47 static void __noreturn sgi_machine_power_off(void)
48 {
49 	unsigned int tmp;
50 
51 	local_irq_disable();
52 
53 	/* Disable watchdog */
54 	tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff;
55 	hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM;
56 	hpc3c0->rtcregs[RTC_WSEC] = 0;
57 	hpc3c0->rtcregs[RTC_WHSEC] = 0;
58 
59 	while (1) {
60 		sgioc->panel = ~SGIOC_PANEL_POWERON;
61 		/* Good bye cruel world ...  */
62 
63 		/* If we're still running, we probably got sent an alarm
64 		   interrupt.  Read the flag to clear it.  */
65 		tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM];
66 	}
67 }
68 
69 static void __noreturn sgi_machine_restart(char *command)
70 {
71 	if (machine_state & MACHINE_SHUTTING_DOWN)
72 		sgi_machine_power_off();
73 	sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
74 	while (1);
75 }
76 
77 static void __noreturn sgi_machine_halt(void)
78 {
79 	if (machine_state & MACHINE_SHUTTING_DOWN)
80 		sgi_machine_power_off();
81 	ArcEnterInteractiveMode();
82 }
83 
84 static void power_timeout(unsigned long data)
85 {
86 	sgi_machine_power_off();
87 }
88 
89 static void blink_timeout(unsigned long data)
90 {
91 	/* XXX fix this for fullhouse  */
92 	sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
93 	sgioc->reset = sgi_ioc_reset;
94 
95 	mod_timer(&blink_timer, jiffies + data);
96 }
97 
98 static void debounce(unsigned long data)
99 {
100 	del_timer(&debounce_timer);
101 	if (sgint->istat1 & SGINT_ISTAT1_PWR) {
102 		/* Interrupt still being sent. */
103 		debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s	*/
104 		add_timer(&debounce_timer);
105 
106 		sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
107 			       SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
108 			       SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;
109 
110 		return;
111 	}
112 
113 	if (machine_state & MACHINE_PANICED)
114 		sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
115 
116 	enable_irq(SGI_PANEL_IRQ);
117 }
118 
119 static inline void power_button(void)
120 {
121 	if (machine_state & MACHINE_PANICED)
122 		return;
123 
124 	if ((machine_state & MACHINE_SHUTTING_DOWN) ||
125 			kill_cad_pid(SIGINT, 1)) {
126 		/* No init process or button pressed twice.  */
127 		sgi_machine_power_off();
128 	}
129 
130 	machine_state |= MACHINE_SHUTTING_DOWN;
131 	blink_timer.data = POWERDOWN_FREQ;
132 	blink_timeout(POWERDOWN_FREQ);
133 
134 	init_timer(&power_timer);
135 	power_timer.function = power_timeout;
136 	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
137 	add_timer(&power_timer);
138 }
139 
140 static irqreturn_t panel_int(int irq, void *dev_id)
141 {
142 	unsigned int buttons;
143 
144 	buttons = sgioc->panel;
145 	sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR;
146 
147 	if (sgint->istat1 & SGINT_ISTAT1_PWR) {
148 		/* Wait until interrupt goes away */
149 		disable_irq_nosync(SGI_PANEL_IRQ);
150 		init_timer(&debounce_timer);
151 		debounce_timer.function = debounce;
152 		debounce_timer.expires = jiffies + 5;
153 		add_timer(&debounce_timer);
154 	}
155 
156 	/* Power button was pressed
157 	 * ioc.ps page 22: "The Panel Register is called Power Control by Full
158 	 * House. Only lowest 2 bits are used. Guiness uses upper four bits
159 	 * for volume control". This is not true, all bits are pulled high
160 	 * on fullhouse */
161 	if (!(buttons & SGIOC_PANEL_POWERINTR))
162 		power_button();
163 
164 	return IRQ_HANDLED;
165 }
166 
167 static int panic_event(struct notifier_block *this, unsigned long event,
168 		      void *ptr)
169 {
170 	if (machine_state & MACHINE_PANICED)
171 		return NOTIFY_DONE;
172 	machine_state |= MACHINE_PANICED;
173 
174 	blink_timer.data = PANIC_FREQ;
175 	blink_timeout(PANIC_FREQ);
176 
177 	return NOTIFY_DONE;
178 }
179 
180 static struct notifier_block panic_block = {
181 	.notifier_call	= panic_event,
182 };
183 
184 static int __init reboot_setup(void)
185 {
186 	int res;
187 
188 	_machine_restart = sgi_machine_restart;
189 	_machine_halt = sgi_machine_halt;
190 	pm_power_off = sgi_machine_power_off;
191 
192 	res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
193 	if (res) {
194 		printk(KERN_ERR "Allocation of front panel IRQ failed\n");
195 		return res;
196 	}
197 
198 	init_timer(&blink_timer);
199 	blink_timer.function = blink_timeout;
200 	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
201 
202 	return 0;
203 }
204 
205 subsys_initcall(reboot_setup);
206