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
40 static struct timer_list power_timer, blink_timer, debounce_timer;
41 static unsigned long blink_timer_timeout;
42
43 #define MACHINE_PANICKED 1
44 #define MACHINE_SHUTTING_DOWN 2
45
46 static int machine_state;
47
48 static 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
70 static 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
78 static void __noreturn sgi_machine_halt(void)
79 {
80 if (machine_state & MACHINE_SHUTTING_DOWN)
81 sgi_machine_power_off();
82 ArcEnterInteractiveMode();
83 }
84
85 static void power_timeout(struct timer_list *unused)
86 {
87 sgi_machine_power_off();
88 }
89
90 static 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
99 static 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
120 static 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
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 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
166 static 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
179 static struct notifier_block panic_block = {
180 .notifier_call = panic_event,
181 };
182
183 static 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
203 subsys_initcall(reboot_setup);
204
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