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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02002 * linux/drivers/parisc/power.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * HP PARISC soft power switch support driver
4 *
Helge Deller8039de12006-01-10 20:35:03 -05005 * Copyright (c) 2001-2005 Helge Deller <deller@gmx.de>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * All rights reserved.
7 *
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions, and the following disclaimer,
14 * without modification.
15 * 2. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * Alternatively, this software may be distributed under the terms of the
19 * GNU General Public License ("GPL").
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
25 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 *
31 *
32 *
33 * HINT:
34 * Support of the soft power switch button may be enabled or disabled at
35 * runtime through the "/proc/sys/kernel/power" procfs entry.
36 */
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/module.h>
39#include <linux/init.h>
40#include <linux/kernel.h>
41#include <linux/string.h>
42#include <linux/notifier.h>
43#include <linux/reboot.h>
44#include <linux/sched.h>
45#include <linux/interrupt.h>
46#include <linux/workqueue.h>
47
48#include <asm/pdc.h>
49#include <asm/io.h>
50#include <asm/led.h>
51#include <asm/uaccess.h>
52
53
54#ifdef DEBUG
55# define DPRINTK(x...) printk(x)
56#else
57# define DPRINTK(x...)
58#endif
59
60
61/* filename in /proc which can be used to enable/disable the power switch */
62#define SYSCTL_FILENAME "sys/kernel/power"
63
64
65#define DIAG_CODE(code) (0x14000000 + ((code)<<5))
66
67/* this will go to processor.h or any other place... */
68/* taken from PCXL ERS page 82 */
69#define MFCPU_X(rDiagReg, t_ch, t_th, code) \
70 (DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
71
72#define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */
73#define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */
74#define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */
75
76#define __getDIAG(dr) ( { \
77 register unsigned long __res asm("r28");\
78 __asm__ __volatile__ ( \
79 ".word %1\n nop\n" : "=&r" (__res) : "i" (MFCPU_T(dr,28)) \
80 ); \
81 __res; \
82} )
83
84
85static void deferred_poweroff(void *dummy)
86{
Cedric Le Goater9ec52092006-10-02 02:19:00 -070087 if (kill_cad_pid(SIGINT, 1)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 /* just in case killing init process failed */
89 machine_power_off();
90 }
91}
92
93/*
94 * This function gets called from interrupt context.
95 * As it's called within an interrupt, it wouldn't sync if we don't
96 * use schedule_work().
97 */
98
99static DECLARE_WORK(poweroff_work, deferred_poweroff, NULL);
100
101static void poweroff(void)
102{
Helge Deller8039de12006-01-10 20:35:03 -0500103 static int powering_off __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105 if (powering_off)
106 return;
107
108 powering_off++;
109 schedule_work(&poweroff_work);
110}
111
112
113/* local time-counter for shutdown */
Helge Deller8039de12006-01-10 20:35:03 -0500114static int shutdown_timer __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115
116/* check, give feedback and start shutdown after one second */
117static void process_shutdown(void)
118{
119 if (shutdown_timer == 0)
120 DPRINTK(KERN_INFO "Shutdown requested...\n");
121
122 shutdown_timer++;
123
124 /* wait until the button was pressed for 1 second */
125 if (shutdown_timer == HZ) {
126#if defined (DEBUG) || defined(CONFIG_CHASSIS_LCD_LED)
127 static char msg[] = "Shutting down...";
128#endif
129 DPRINTK(KERN_INFO "%s\n", msg);
130 lcd_print(msg);
131 poweroff();
132 }
133}
134
135
136/* main power switch tasklet struct (scheduled from time.c) */
137DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0);
138
139/* soft power switch enabled/disabled */
Helge Deller8039de12006-01-10 20:35:03 -0500140int pwrsw_enabled __read_mostly = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142/*
143 * On gecko style machines (e.g. 712/xx and 715/xx)
144 * the power switch status is stored in Bit 0 ("the highest bit")
145 * of CPU diagnose register 25.
146 *
147 */
148static void gecko_tasklet_func(unsigned long unused)
149{
Helge Deller8039de12006-01-10 20:35:03 -0500150 if (unlikely(!pwrsw_enabled))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 return;
152
153 if (__getDIAG(25) & 0x80000000) {
154 /* power switch button not pressed or released again */
155 /* Warning: Some machines do never reset this DIAG flag! */
156 shutdown_timer = 0;
157 } else {
158 process_shutdown();
159 }
160}
161
162
163
164/*
165 * Check the power switch status which is read from the
166 * real I/O location at soft_power_reg.
167 * Bit 31 ("the lowest bit) is the status of the power switch.
168 */
169
170static void polling_tasklet_func(unsigned long soft_power_reg)
171{
172 unsigned long current_status;
173
Helge Deller8039de12006-01-10 20:35:03 -0500174 if (unlikely(!pwrsw_enabled))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 return;
176
177 current_status = gsc_readl(soft_power_reg);
178 if (current_status & 0x1) {
179 /* power switch button not pressed */
180 shutdown_timer = 0;
181 } else {
182 process_shutdown();
183 }
184}
185
186
187/*
188 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
189 */
190#if 0
David Howells7d12e782006-10-05 14:55:46 +0100191static void powerfail_interrupt(int code, void *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
193 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
194 poweroff();
195}
196#endif
197
198
199
200
201/* parisc_panic_event() is called by the panic handler.
202 * As soon as a panic occurs, our tasklets above will not be
203 * executed any longer. This function then re-enables the
204 * soft-power switch and allows the user to switch off the system
205 */
206static int parisc_panic_event(struct notifier_block *this,
207 unsigned long event, void *ptr)
208{
209 /* re-enable the soft-power switch */
210 pdc_soft_power_button(0);
211 return NOTIFY_DONE;
212}
213
214static struct notifier_block parisc_panic_block = {
215 .notifier_call = parisc_panic_event,
216 .priority = INT_MAX,
217};
218
219
220static int __init power_init(void)
221{
222 unsigned long ret;
223 unsigned long soft_power_reg = 0;
224
225#if 0
226 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
227 0, "powerfail", NULL);
228#endif
229
230 /* enable the soft power switch if possible */
231 ret = pdc_soft_power_info(&soft_power_reg);
232 if (ret == PDC_OK)
233 ret = pdc_soft_power_button(1);
234 if (ret != PDC_OK)
235 soft_power_reg = -1UL;
236
237 switch (soft_power_reg) {
238 case 0: printk(KERN_INFO "Gecko-style soft power switch enabled.\n");
239 power_tasklet.func = gecko_tasklet_func;
240 break;
241
242 case -1UL: printk(KERN_INFO "Soft power switch support not available.\n");
243 return -ENODEV;
244
245 default: printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n",
246 soft_power_reg);
247 power_tasklet.data = soft_power_reg;
248 power_tasklet.func = polling_tasklet_func;
249 }
250
251 /* Register a call for panic conditions. */
Alan Sterne041c682006-03-27 01:16:30 -0800252 atomic_notifier_chain_register(&panic_notifier_list,
253 &parisc_panic_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255 tasklet_enable(&power_tasklet);
256
257 return 0;
258}
259
260static void __exit power_exit(void)
261{
262 if (!power_tasklet.func)
263 return;
264
265 tasklet_disable(&power_tasklet);
Alan Sterne041c682006-03-27 01:16:30 -0800266 atomic_notifier_chain_unregister(&panic_notifier_list,
267 &parisc_panic_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 power_tasklet.func = NULL;
269 pdc_soft_power_button(0);
270}
271
272module_init(power_init);
273module_exit(power_exit);
274
275
276MODULE_AUTHOR("Helge Deller");
277MODULE_DESCRIPTION("Soft power switch driver");
278MODULE_LICENSE("Dual BSD/GPL");