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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/parisc/kernel/power.c
3 * HP PARISC soft power switch support driver
4 *
5 * Copyright (c) 2001-2002 Helge Deller <deller@gmx.de>
6 * 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
38#include <linux/config.h>
39#include <linux/module.h>
40#include <linux/init.h>
41#include <linux/kernel.h>
42#include <linux/string.h>
43#include <linux/notifier.h>
44#include <linux/reboot.h>
45#include <linux/sched.h>
46#include <linux/interrupt.h>
47#include <linux/workqueue.h>
48
49#include <asm/pdc.h>
50#include <asm/io.h>
51#include <asm/led.h>
52#include <asm/uaccess.h>
53
54
55#ifdef DEBUG
56# define DPRINTK(x...) printk(x)
57#else
58# define DPRINTK(x...)
59#endif
60
61
62/* filename in /proc which can be used to enable/disable the power switch */
63#define SYSCTL_FILENAME "sys/kernel/power"
64
65
66#define DIAG_CODE(code) (0x14000000 + ((code)<<5))
67
68/* this will go to processor.h or any other place... */
69/* taken from PCXL ERS page 82 */
70#define MFCPU_X(rDiagReg, t_ch, t_th, code) \
71 (DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
72
73#define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */
74#define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */
75#define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */
76
77#define __getDIAG(dr) ( { \
78 register unsigned long __res asm("r28");\
79 __asm__ __volatile__ ( \
80 ".word %1\n nop\n" : "=&r" (__res) : "i" (MFCPU_T(dr,28)) \
81 ); \
82 __res; \
83} )
84
85
86static void deferred_poweroff(void *dummy)
87{
88 extern int cad_pid; /* from kernel/sys.c */
89 if (kill_proc(cad_pid, SIGINT, 1)) {
90 /* just in case killing init process failed */
91 machine_power_off();
92 }
93}
94
95/*
96 * This function gets called from interrupt context.
97 * As it's called within an interrupt, it wouldn't sync if we don't
98 * use schedule_work().
99 */
100
101static DECLARE_WORK(poweroff_work, deferred_poweroff, NULL);
102
103static void poweroff(void)
104{
105 static int powering_off;
106
107 if (powering_off)
108 return;
109
110 powering_off++;
111 schedule_work(&poweroff_work);
112}
113
114
115/* local time-counter for shutdown */
116static int shutdown_timer;
117
118/* check, give feedback and start shutdown after one second */
119static void process_shutdown(void)
120{
121 if (shutdown_timer == 0)
122 DPRINTK(KERN_INFO "Shutdown requested...\n");
123
124 shutdown_timer++;
125
126 /* wait until the button was pressed for 1 second */
127 if (shutdown_timer == HZ) {
128#if defined (DEBUG) || defined(CONFIG_CHASSIS_LCD_LED)
129 static char msg[] = "Shutting down...";
130#endif
131 DPRINTK(KERN_INFO "%s\n", msg);
132 lcd_print(msg);
133 poweroff();
134 }
135}
136
137
138/* main power switch tasklet struct (scheduled from time.c) */
139DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0);
140
141/* soft power switch enabled/disabled */
142int pwrsw_enabled = 1;
143
144/*
145 * On gecko style machines (e.g. 712/xx and 715/xx)
146 * the power switch status is stored in Bit 0 ("the highest bit")
147 * of CPU diagnose register 25.
148 *
149 */
150static void gecko_tasklet_func(unsigned long unused)
151{
152 if (!pwrsw_enabled)
153 return;
154
155 if (__getDIAG(25) & 0x80000000) {
156 /* power switch button not pressed or released again */
157 /* Warning: Some machines do never reset this DIAG flag! */
158 shutdown_timer = 0;
159 } else {
160 process_shutdown();
161 }
162}
163
164
165
166/*
167 * Check the power switch status which is read from the
168 * real I/O location at soft_power_reg.
169 * Bit 31 ("the lowest bit) is the status of the power switch.
170 */
171
172static void polling_tasklet_func(unsigned long soft_power_reg)
173{
174 unsigned long current_status;
175
176 if (!pwrsw_enabled)
177 return;
178
179 current_status = gsc_readl(soft_power_reg);
180 if (current_status & 0x1) {
181 /* power switch button not pressed */
182 shutdown_timer = 0;
183 } else {
184 process_shutdown();
185 }
186}
187
188
189/*
190 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
191 */
192#if 0
193static void powerfail_interrupt(int code, void *x, struct pt_regs *regs)
194{
195 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
196 poweroff();
197}
198#endif
199
200
201
202
203/* parisc_panic_event() is called by the panic handler.
204 * As soon as a panic occurs, our tasklets above will not be
205 * executed any longer. This function then re-enables the
206 * soft-power switch and allows the user to switch off the system
207 */
208static int parisc_panic_event(struct notifier_block *this,
209 unsigned long event, void *ptr)
210{
211 /* re-enable the soft-power switch */
212 pdc_soft_power_button(0);
213 return NOTIFY_DONE;
214}
215
216static struct notifier_block parisc_panic_block = {
217 .notifier_call = parisc_panic_event,
218 .priority = INT_MAX,
219};
220
221
222static int __init power_init(void)
223{
224 unsigned long ret;
225 unsigned long soft_power_reg = 0;
226
227#if 0
228 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
229 0, "powerfail", NULL);
230#endif
231
232 /* enable the soft power switch if possible */
233 ret = pdc_soft_power_info(&soft_power_reg);
234 if (ret == PDC_OK)
235 ret = pdc_soft_power_button(1);
236 if (ret != PDC_OK)
237 soft_power_reg = -1UL;
238
239 switch (soft_power_reg) {
240 case 0: printk(KERN_INFO "Gecko-style soft power switch enabled.\n");
241 power_tasklet.func = gecko_tasklet_func;
242 break;
243
244 case -1UL: printk(KERN_INFO "Soft power switch support not available.\n");
245 return -ENODEV;
246
247 default: printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n",
248 soft_power_reg);
249 power_tasklet.data = soft_power_reg;
250 power_tasklet.func = polling_tasklet_func;
251 }
252
253 /* Register a call for panic conditions. */
254 notifier_chain_register(&panic_notifier_list, &parisc_panic_block);
255
256 tasklet_enable(&power_tasklet);
257
258 return 0;
259}
260
261static void __exit power_exit(void)
262{
263 if (!power_tasklet.func)
264 return;
265
266 tasklet_disable(&power_tasklet);
267 notifier_chain_unregister(&panic_notifier_list, &parisc_panic_block);
268 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");