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/arch/mips/sgi-ip22/ip22-reset.c

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35
C | 207 lines | 139 code | 40 blank | 28 comment | 12 complexity | a3f1289537b51c70cda66ae9ab42d1dd MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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/ds1286.h>
 11#include <linux/module.h>
 12#include <linux/interrupt.h>
 13#include <linux/kernel.h>
 14#include <linux/sched.h>
 15#include <linux/notifier.h>
 16#include <linux/pm.h>
 17#include <linux/timer.h>
 18
 19#include <asm/io.h>
 20#include <asm/irq.h>
 21#include <asm/system.h>
 22#include <asm/reboot.h>
 23#include <asm/sgialib.h>
 24#include <asm/sgi/ioc.h>
 25#include <asm/sgi/hpc3.h>
 26#include <asm/sgi/mc.h>
 27#include <asm/sgi/ip22.h>
 28
 29/*
 30 * Just powerdown if init hasn't done after POWERDOWN_TIMEOUT seconds.
 31 * I'm not sure if this feature is a good idea, for now it's here just to
 32 * make the power button make behave just like under IRIX.
 33 */
 34#define POWERDOWN_TIMEOUT	120
 35
 36/*
 37 * Blink frequency during reboot grace period and when panicked.
 38 */
 39#define POWERDOWN_FREQ		(HZ / 4)
 40#define PANIC_FREQ		(HZ / 8)
 41
 42static struct timer_list power_timer, blink_timer, debounce_timer;
 43
 44#define MACHINE_PANICED		1
 45#define MACHINE_SHUTTING_DOWN	2
 46
 47static int machine_state;
 48
 49static void __noreturn sgi_machine_power_off(void)
 50{
 51	unsigned int tmp;
 52
 53	local_irq_disable();
 54
 55	/* Disable watchdog */
 56	tmp = hpc3c0->rtcregs[RTC_CMD] & 0xff;
 57	hpc3c0->rtcregs[RTC_CMD] = tmp | RTC_WAM;
 58	hpc3c0->rtcregs[RTC_WSEC] = 0;
 59	hpc3c0->rtcregs[RTC_WHSEC] = 0;
 60
 61	while (1) {
 62		sgioc->panel = ~SGIOC_PANEL_POWERON;
 63		/* Good bye cruel world ...  */
 64
 65		/* If we're still running, we probably got sent an alarm
 66		   interrupt.  Read the flag to clear it.  */
 67		tmp = hpc3c0->rtcregs[RTC_HOURS_ALARM];
 68	}
 69}
 70
 71static void __noreturn sgi_machine_restart(char *command)
 72{
 73	if (machine_state & MACHINE_SHUTTING_DOWN)
 74		sgi_machine_power_off();
 75	sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
 76	while (1);
 77}
 78
 79static void __noreturn sgi_machine_halt(void)
 80{
 81	if (machine_state & MACHINE_SHUTTING_DOWN)
 82		sgi_machine_power_off();
 83	ArcEnterInteractiveMode();
 84}
 85
 86static void power_timeout(unsigned long data)
 87{
 88	sgi_machine_power_off();
 89}
 90
 91static void blink_timeout(unsigned long data)
 92{
 93	/* XXX fix this for fullhouse  */
 94	sgi_ioc_reset ^= (SGIOC_RESET_LC0OFF|SGIOC_RESET_LC1OFF);
 95	sgioc->reset = sgi_ioc_reset;
 96
 97	mod_timer(&blink_timer, jiffies + data);
 98}
 99
100static void debounce(unsigned long data)
101{
102	del_timer(&debounce_timer);
103	if (sgint->istat1 & SGINT_ISTAT1_PWR) {
104		/* Interrupt still being sent. */
105		debounce_timer.expires = jiffies + (HZ / 20); /* 0.05s  */
106		add_timer(&debounce_timer);
107
108		sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR |
109			       SGIOC_PANEL_VOLDNINTR | SGIOC_PANEL_VOLDNHOLD |
110			       SGIOC_PANEL_VOLUPINTR | SGIOC_PANEL_VOLUPHOLD;
111
112		return;
113	}
114
115	if (machine_state & MACHINE_PANICED)
116		sgimc->cpuctrl0 |= SGIMC_CCTRL0_SYSINIT;
117
118	enable_irq(SGI_PANEL_IRQ);
119}
120
121static inline void power_button(void)
122{
123	if (machine_state & MACHINE_PANICED)
124		return;
125
126	if ((machine_state & MACHINE_SHUTTING_DOWN) ||
127			kill_cad_pid(SIGINT, 1)) {
128		/* No init process or button pressed twice.  */
129		sgi_machine_power_off();
130	}
131
132	machine_state |= MACHINE_SHUTTING_DOWN;
133	blink_timer.data = POWERDOWN_FREQ;
134	blink_timeout(POWERDOWN_FREQ);
135
136	init_timer(&power_timer);
137	power_timer.function = power_timeout;
138	power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
139	add_timer(&power_timer);
140}
141
142static irqreturn_t panel_int(int irq, void *dev_id)
143{
144	unsigned int buttons;
145
146	buttons = sgioc->panel;
147	sgioc->panel = SGIOC_PANEL_POWERON | SGIOC_PANEL_POWERINTR;
148
149	if (sgint->istat1 & SGINT_ISTAT1_PWR) {
150		/* Wait until interrupt goes away */
151		disable_irq_nosync(SGI_PANEL_IRQ);
152		init_timer(&debounce_timer);
153		debounce_timer.function = debounce;
154		debounce_timer.expires = jiffies + 5;
155		add_timer(&debounce_timer);
156	}
157
158	/* Power button was pressed
159	 * ioc.ps page 22: "The Panel Register is called Power Control by Full
160	 * House. Only lowest 2 bits are used. Guiness uses upper four bits
161	 * for volume control". This is not true, all bits are pulled high
162	 * on fullhouse */
163	if (!(buttons & SGIOC_PANEL_POWERINTR))
164		power_button();
165
166	return IRQ_HANDLED;
167}
168
169static int panic_event(struct notifier_block *this, unsigned long event,
170                      void *ptr)
171{
172	if (machine_state & MACHINE_PANICED)
173		return NOTIFY_DONE;
174	machine_state |= MACHINE_PANICED;
175
176	blink_timer.data = PANIC_FREQ;
177	blink_timeout(PANIC_FREQ);
178
179	return NOTIFY_DONE;
180}
181
182static struct notifier_block panic_block = {
183	.notifier_call	= panic_event,
184};
185
186static int __init reboot_setup(void)
187{
188	int res;
189
190	_machine_restart = sgi_machine_restart;
191	_machine_halt = sgi_machine_halt;
192	pm_power_off = sgi_machine_power_off;
193
194	res = request_irq(SGI_PANEL_IRQ, panel_int, 0, "Front Panel", NULL);
195	if (res) {
196		printk(KERN_ERR "Allocation of front panel IRQ failed\n");
197		return res;
198	}
199
200	init_timer(&blink_timer);
201	blink_timer.function = blink_timeout;
202	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
203
204	return 0;
205}
206
207subsys_initcall(reboot_setup);