2 * linux/arch/parisc/kernel/power.c
3 * HP PARISC soft power switch support driver
5 * Copyright (c) 2001-2002 Helge Deller <deller@gmx.de>
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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.
18 * Alternatively, this software may be distributed under the terms of the
19 * GNU General Public License ("GPL").
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
34 * Support of the soft power switch button may be enabled or disabled at
35 * runtime through the "/proc/sys/kernel/power" procfs entry.
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>
53 #include <asm/uaccess.h>
57 # define DPRINTK(x) printk x
59 # define DPRINTK(x) do { } while (0)
63 /* filename in /proc which can be used to enable/disable the power switch */
64 #define SYSCTL_FILENAME "sys/kernel/power"
67 #define DIAG_CODE(code) (0x14000000 + ((code)<<5))
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) )
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 */
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)) \
87 static void deferred_poweroff(void *dummy)
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 */
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_work().
102 static DECLARE_WORK(poweroff_work, deferred_poweroff, NULL);
104 static void poweroff(void)
106 static int powering_off;
112 schedule_work(&poweroff_work);
116 /* local time-counter for shutdown */
117 static int shutdown_timer;
119 /* check, give feedback and start shutdown after one second */
120 static void process_shutdown(void)
122 if (shutdown_timer == 0)
123 DPRINTK((KERN_INFO "Shutdown requested...\n"));
127 /* wait until the button was pressed for 1 second */
128 if (shutdown_timer == HZ) {
129 static char msg[] = "Shutting down...";
130 DPRINTK((KERN_INFO "%s\n", msg));
131 #ifdef CONFIG_CHASSIS_LCD_LED
139 /* main power switch tasklet struct (scheduled from time.c) */
140 DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0);
142 /* soft power switch enabled/disabled */
143 int pwrsw_enabled = 1;
146 * On gecko style machines (e.g. 712/xx and 715/xx)
147 * the power switch status is stored in Bit 0 ("the highest bit")
148 * of CPU diagnose register 25.
151 static void gecko_tasklet_func(unsigned long unused)
156 if (__getDIAG(25) & 0x80000000) {
157 /* power switch button not pressed or released again */
158 /* Warning: Some machines do never reset this DIAG flag! */
168 * Check the power switch status which is read from the
169 * real I/O location at soft_power_reg.
170 * Bit 31 ("the lowest bit) is the status of the power switch.
173 static void polling_tasklet_func(unsigned long soft_power_reg)
175 unsigned long current_status;
180 current_status = gsc_readl(soft_power_reg);
181 if (current_status & 0x1) {
182 /* power switch button not pressed */
191 * powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
194 static void powerfail_interrupt(int code, void *x, struct pt_regs *regs)
196 printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
204 /* parisc_panic_event() is called by the panic handler.
205 * As soon as a panic occurs, our tasklets above will not be
206 * executed any longer. This function then re-enables the
207 * soft-power switch and allows the user to switch off the system
209 static int parisc_panic_event(struct notifier_block *this,
210 unsigned long event, void *ptr)
212 /* re-enable the soft-power switch */
213 pdc_soft_power_button(0);
217 static struct notifier_block parisc_panic_block = {
218 .notifier_call = parisc_panic_event,
223 static int __init power_init(void)
226 unsigned long soft_power_reg = 0;
229 request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
230 0, "powerfail", NULL);
233 /* enable the soft power switch if possible */
234 ret = pdc_soft_power_info(&soft_power_reg);
236 ret = pdc_soft_power_button(1);
238 soft_power_reg = -1UL;
240 switch (soft_power_reg) {
241 case 0: printk(KERN_INFO "Gecko-style soft power switch enabled.\n");
242 power_tasklet.func = gecko_tasklet_func;
245 case -1UL: printk(KERN_INFO "Soft power switch support not available.\n");
248 default: printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n",
250 power_tasklet.data = soft_power_reg;
251 power_tasklet.func = polling_tasklet_func;
254 /* Register a call for panic conditions. */
255 notifier_chain_register(&panic_notifier_list, &parisc_panic_block);
257 tasklet_enable(&power_tasklet);
262 static void __exit power_exit(void)
264 if (!power_tasklet.func)
267 tasklet_disable(&power_tasklet);
268 notifier_chain_unregister(&panic_notifier_list, &parisc_panic_block);
269 power_tasklet.func = NULL;
270 pdc_soft_power_button(0);
273 module_init(power_init);
274 module_exit(power_exit);
277 MODULE_AUTHOR("Helge Deller");
278 MODULE_DESCRIPTION("Soft power switch driver");
279 MODULE_LICENSE("Dual BSD/GPL");