1 /*
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
48 #include <asm/gsc.h>
49 #include <asm/pdc.h>
50 #include <asm/irq.h>
51 #include <asm/io.h>
52 #include <asm/led.h>
53 #include <asm/uaccess.h>
54
55
56 #ifdef DEBUG
57 # define DPRINTK(x) printk x
58 #else
59 # define DPRINTK(x) do { } while (0)
60 #endif
61
62
63 /* filename in /proc which can be used to enable/disable the power switch */
64 #define SYSCTL_FILENAME "sys/kernel/power"
65
66
67 #define DIAG_CODE(code) (0x14000000 + ((code)<<5))
68
69 /* this will go to processor.h or any other place... */
70 /* taken from PCXL ERS page 82 */
71 #define MFCPU_X(rDiagReg, t_ch, t_th, code) \
72 (DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
73
74 #define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */
75 #define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */
76 #define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */
77
78 #define __getDIAG(dr) ( { \
79 register unsigned long __res asm("r28");\
80 __asm__ __volatile__ ( \
81 ".word %1\n nop\n" : "=&r" (__res) : "i" (MFCPU_T(dr,28)) \
82 ); \
83 __res; \
84 } )
85
86
deferred_poweroff(void * dummy)87 static void deferred_poweroff(void *dummy)
88 {
89 extern int cad_pid; /* from kernel/sys.c */
90 if (kill_proc(cad_pid, SIGINT, 1)) {
91 /* just in case killing init process failed */
92 machine_power_off();
93 }
94 }
95
96 /*
97 * This function gets called from interrupt context.
98 * As it's called within an interrupt, it wouldn't sync if we don't
99 * use schedule_task().
100 */
101
poweroff(void)102 static void poweroff(void)
103 {
104 static int powering_off;
105 static struct tq_struct poweroff_tq = {
106 routine: deferred_poweroff,
107 };
108
109 if (powering_off)
110 return;
111
112 powering_off++;
113 schedule_task(&poweroff_tq);
114 }
115
116
117 /* local time-counter for shutdown */
118 static int shutdown_timer;
119
120 /* check, give feedback and start shutdown after one second */
process_shutdown(void)121 static void process_shutdown(void)
122 {
123 if (shutdown_timer == 0)
124 DPRINTK((KERN_INFO "Shutdown requested...\n"));
125
126 shutdown_timer++;
127
128 /* wait until the button was pressed for 1 second */
129 if (shutdown_timer == HZ) {
130 static char msg[] = "Shutting down...";
131 DPRINTK((KERN_INFO "%s\n", msg));
132 #ifdef CONFIG_CHASSIS_LCD_LED
133 lcd_print(msg);
134 #endif
135 poweroff();
136 }
137 }
138
139
140 /* main power switch tasklet struct (scheduled from time.c) */
141 DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0);
142
143 /* soft power switch enabled/disabled */
144 int pwrsw_enabled = 1;
145
146 /*
147 * On gecko style machines (e.g. 712/xx and 715/xx)
148 * the power switch status is stored in Bit 0 ("the highest bit")
149 * of CPU diagnose register 25.
150 *
151 */
gecko_tasklet_func(unsigned long unused)152 static void gecko_tasklet_func(unsigned long unused)
153 {
154 if (!pwrsw_enabled)
155 return;
156
157 if (__getDIAG(25) & 0x80000000) {
158 /* power switch button not pressed or released again */
159 /* Warning: Some machines do never reset this DIAG flag! */
160 shutdown_timer = 0;
161 } else {
162 process_shutdown();
163 }
164 }
165
166
167
168 /*
169 * Check the power switch status which is read from the
170 * real I/O location at soft_power_reg.
171 * Bit 31 ("the lowest bit) is the status of the power switch.
172 */
173
polling_tasklet_func(unsigned long soft_power_reg)174 static void polling_tasklet_func(unsigned long soft_power_reg)
175 {
176 unsigned long current_status;
177
178 if (!pwrsw_enabled)
179 return;
180
181 current_status = gsc_readl(soft_power_reg);
182 if (current_status & 0x1) {
183 /* power switch button not pressed */
184 shutdown_timer = 0;
185 } else {
186 process_shutdown();
187 }
188 }
189
190
191 /*
192 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
193 */
194 #if 0
195 static void powerfail_interrupt(int code, void *x, struct pt_regs *regs)
196 {
197 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
198 poweroff();
199 }
200 #endif
201
202
203
204
205 /* parisc_panic_event() is called by the panic handler.
206 * As soon as a panic occurs, our tasklets above will not be
207 * executed any longer. This function then re-enables the
208 * soft-power switch and allows the user to switch off the system
209 */
parisc_panic_event(struct notifier_block * this,unsigned long event,void * ptr)210 static int parisc_panic_event(struct notifier_block *this,
211 unsigned long event, void *ptr)
212 {
213 /* re-enable the soft-power switch */
214 pdc_soft_power_button(0);
215 return NOTIFY_DONE;
216 }
217
218 static struct notifier_block parisc_panic_block = {
219 notifier_call: parisc_panic_event,
220 priority: INT_MAX,
221 };
222
223
power_init(void)224 static int __init power_init(void)
225 {
226 unsigned long ret;
227 unsigned long soft_power_reg = 0;
228
229 #if 0
230 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
231 0, "powerfail", NULL);
232 #endif
233
234 /* enable the soft power switch if possible */
235 ret = pdc_soft_power_info(&soft_power_reg);
236 if (ret == PDC_OK)
237 ret = pdc_soft_power_button(1);
238 if (ret != PDC_OK)
239 soft_power_reg = -1UL;
240
241 switch (soft_power_reg) {
242 case 0: printk(KERN_INFO "Gecko-style soft power switch enabled.\n");
243 power_tasklet.func = gecko_tasklet_func;
244 break;
245
246 case -1UL: printk(KERN_INFO "Soft power switch support not available.\n");
247 return -ENODEV;
248
249 default: printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n",
250 soft_power_reg);
251 power_tasklet.data = soft_power_reg;
252 power_tasklet.func = polling_tasklet_func;
253 }
254
255 /* Register a call for panic conditions. */
256 notifier_chain_register(&panic_notifier_list, &parisc_panic_block);
257
258 tasklet_enable(&power_tasklet);
259
260 return 0;
261 }
262
power_exit(void)263 static void __exit power_exit(void)
264 {
265 if (!power_tasklet.func)
266 return;
267
268 tasklet_disable(&power_tasklet);
269 notifier_chain_unregister(&panic_notifier_list, &parisc_panic_block);
270 power_tasklet.func = NULL;
271 pdc_soft_power_button(0);
272 }
273
274 module_init(power_init);
275 module_exit(power_exit);
276
277
278 MODULE_AUTHOR("Helge Deller");
279 MODULE_DESCRIPTION("Soft power switch driver");
280 MODULE_LICENSE("Dual BSD/GPL");
281
282
283 EXPORT_NO_SYMBOLS;
284
285