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/panic_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
40static struct timer_list power_timer, blink_timer, debounce_timer;
41static unsigned long blink_timer_timeout;
42
43#define MACHINE_PANICKED		1
44#define MACHINE_SHUTTING_DOWN	2
45
46static int machine_state;
47
48static void __noreturn sgi_machine_power_off(void)
49{
50	unsigned int tmp;
51
52	local_irq_disable();
53
54	/* Disable watchdog */
55	tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff;
56	hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM;
57	hpc3c0->rtcregs[RTC_WSEC] = 0;
58	hpc3c0->rtcregs[RTC_WHSEC] = 0;
59
60	while (1) {
61		sgioc->panel = ~SGIOC_PANEL_POWERON;
62		/* Good bye cruel world ...  */
63
64		/* If we're still running, we probably got sent an alarm
65		   interrupt.  Read the flag to clear it.  */
66		tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM];
67	}
68}
69
70static void __noreturn sgi_machine_restart(char *command)
71{
72	if (machine_state & MACHINE_SHUTTING_DOWN)
73		sgi_machine_power_off();
74	sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
75	while (1);
76}
77
78static void __noreturn sgi_machine_halt(void)
79{
80	if (machine_state & MACHINE_SHUTTING_DOWN)
81		sgi_machine_power_off();
82	ArcEnterInteractiveMode();
83}
84
85static void power_timeout(struct timer_list *unused)
86{
87	sgi_machine_power_off();
88}
89
90static void blink_timeout(struct timer_list *unused)
91{
92	/* XXX fix this for fullhouse  */
93	sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
94	sgioc->reset = sgi_ioc_reset;
95
96	mod_timer(&blink_timer, jiffies + blink_timer_timeout);
97}
98
99static void debounce(struct timer_list *unused)
100{
101	del_timer(&debounce_timer);
102	if (sgint->istat1 & SGINT_ISTAT1_PWR) {
103		/* Interrupt still being sent. */
104		debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s	*/
105		add_timer(&debounce_timer);
106
107		sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
108			       SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
109			       SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;
110
111		return;
112	}
113
114	if (machine_state & MACHINE_PANICKED)
115		sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
116
117	enable_irq(SGI_PANEL_IRQ);
118}
119
120static inline void power_button(void)
121{
122	if (machine_state & MACHINE_PANICKED)
123		return;
124
125	if ((machine_state & MACHINE_SHUTTING_DOWN) ||
126			kill_cad_pid(SIGINT, 1)) {
127		/* No init process or button pressed twice.  */
128		sgi_machine_power_off();
129	}
130
131	machine_state |= MACHINE_SHUTTING_DOWN;
132	blink_timer_timeout = POWERDOWN_FREQ;
133	blink_timeout(&blink_timer);
134
135	timer_setup(&power_timer, power_timeout, 0);
136	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
137	add_timer(&power_timer);
138}
139
140static 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		timer_setup(&debounce_timer, debounce, 0);
151		debounce_timer.expires = jiffies + 5;
152		add_timer(&debounce_timer);
153	}
154
155	/* Power button was pressed
156	 * ioc.ps page 22: "The Panel Register is called Power Control by Full
157	 * House. Only lowest 2 bits are used. Guiness uses upper four bits
158	 * for volume control". This is not true, all bits are pulled high
159	 * on fullhouse */
160	if (!(buttons & SGIOC_PANEL_POWERINTR))
161		power_button();
162
163	return IRQ_HANDLED;
164}
165
166static int panic_event(struct notifier_block *this, unsigned long event,
167		      void *ptr)
168{
169	if (machine_state & MACHINE_PANICKED)
170		return NOTIFY_DONE;
171	machine_state |= MACHINE_PANICKED;
172
173	blink_timer_timeout = PANIC_FREQ;
174	blink_timeout(&blink_timer);
175
176	return NOTIFY_DONE;
177}
178
179static struct notifier_block panic_block = {
180	.notifier_call	= panic_event,
181};
182
183static int __init reboot_setup(void)
184{
185	int res;
186
187	_machine_restart = sgi_machine_restart;
188	_machine_halt = sgi_machine_halt;
189	pm_power_off = sgi_machine_power_off;
190
191	res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
192	if (res) {
193		printk(KERN_ERR "Allocation of front panel IRQ failed\n");
194		return res;
195	}
196
197	timer_setup(&blink_timer, blink_timeout, 0);
198	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
199
200	return 0;
201}
202
203subsys_initcall(reboot_setup);
204