260 lines
7.4 KiB
C
260 lines
7.4 KiB
C
/*
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* linux/drivers/parisc/power.c
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* HP PARISC soft power switch support driver
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*
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* Copyright (c) 2001-2007 Helge Deller <deller@gmx.de>
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* All rights reserved.
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*
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions, and the following disclaimer,
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* without modification.
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* 2. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* Alternatively, this software may be distributed under the terms of the
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* GNU General Public License ("GPL").
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
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* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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*
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*
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* HINT:
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* Support of the soft power switch button may be enabled or disabled at
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* runtime through the "/proc/sys/kernel/power" procfs entry.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/panic_notifier.h>
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#include <linux/reboot.h>
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#include <linux/sched/signal.h>
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#include <linux/kthread.h>
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#include <linux/pm.h>
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#include <asm/pdc.h>
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#include <asm/io.h>
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#include <asm/led.h>
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#define DRIVER_NAME "powersw"
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#define KTHREAD_NAME "kpowerswd"
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/* how often should the power button be polled ? */
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#define POWERSWITCH_POLL_PER_SEC 2
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/* how long does the power button needs to be down until we react ? */
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#define POWERSWITCH_DOWN_SEC 2
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/* assembly code to access special registers */
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/* taken from PCXL ERS page 82 */
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#define DIAG_CODE(code) (0x14000000 + ((code)<<5))
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#define MFCPU_X(rDiagReg, t_ch, t_th, code) \
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(DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
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#define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */
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#define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */
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#define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */
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#define __getDIAG(dr) ( { \
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register unsigned long __res asm("r28");\
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__asm__ __volatile__ ( \
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".word %1" : "=&r" (__res) : "i" (MFCPU_T(dr,28) ) \
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); \
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__res; \
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} )
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/* local shutdown counter */
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static int shutdown_timer __read_mostly;
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/* check, give feedback and start shutdown after one second */
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static void process_shutdown(void)
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{
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if (shutdown_timer == 0)
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printk(KERN_ALERT KTHREAD_NAME ": Shutdown requested...\n");
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shutdown_timer++;
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/* wait until the button was pressed for 1 second */
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if (shutdown_timer == (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC)) {
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static const char msg[] = "Shutting down...";
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printk(KERN_INFO KTHREAD_NAME ": %s\n", msg);
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lcd_print(msg);
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/* send kill signal */
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if (kill_cad_pid(SIGINT, 1)) {
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/* just in case killing init process failed */
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machine_power_off();
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}
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}
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}
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/* main power switch task struct */
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static struct task_struct *power_task;
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/* filename in /proc which can be used to enable/disable the power switch */
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#define SYSCTL_FILENAME "sys/kernel/power"
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/* soft power switch enabled/disabled */
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int pwrsw_enabled __read_mostly = 1;
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/* main kernel thread worker. It polls the button state */
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static int kpowerswd(void *param)
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{
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__set_current_state(TASK_RUNNING);
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do {
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int button_not_pressed;
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unsigned long soft_power_reg = (unsigned long) param;
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schedule_timeout_interruptible(pwrsw_enabled ? HZ : HZ/POWERSWITCH_POLL_PER_SEC);
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if (unlikely(!pwrsw_enabled))
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continue;
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if (soft_power_reg) {
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/*
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* Non-Gecko-style machines:
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* Check the power switch status which is read from the
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* real I/O location at soft_power_reg.
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* Bit 31 ("the lowest bit) is the status of the power switch.
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* This bit is "1" if the button is NOT pressed.
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*/
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button_not_pressed = (gsc_readl(soft_power_reg) & 0x1);
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} else {
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/*
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* On gecko style machines (e.g. 712/xx and 715/xx)
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* the power switch status is stored in Bit 0 ("the highest bit")
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* of CPU diagnose register 25.
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* Warning: Some machines never reset the DIAG flag, even if
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* the button has been released again.
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*/
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button_not_pressed = (__getDIAG(25) & 0x80000000);
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}
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if (likely(button_not_pressed)) {
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if (unlikely(shutdown_timer && /* avoid writing if not necessary */
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shutdown_timer < (POWERSWITCH_DOWN_SEC*POWERSWITCH_POLL_PER_SEC))) {
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shutdown_timer = 0;
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printk(KERN_INFO KTHREAD_NAME ": Shutdown request aborted.\n");
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}
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} else
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process_shutdown();
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} while (!kthread_should_stop());
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return 0;
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}
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/*
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* powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
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*/
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#if 0
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static void powerfail_interrupt(int code, void *x)
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{
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printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
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poweroff();
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}
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#endif
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/*
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* parisc_panic_event() is called by the panic handler.
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*
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* As soon as a panic occurs, our tasklets above will not
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* be executed any longer. This function then re-enables
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* the soft-power switch and allows the user to switch off
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* the system. We rely in pdc_soft_power_button_panic()
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* since this version spin_trylocks (instead of regular
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* spinlock), preventing deadlocks on panic path.
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*/
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static int parisc_panic_event(struct notifier_block *this,
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unsigned long event, void *ptr)
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{
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/* re-enable the soft-power switch */
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pdc_soft_power_button_panic(0);
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return NOTIFY_DONE;
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}
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static struct notifier_block parisc_panic_block = {
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.notifier_call = parisc_panic_event,
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.priority = INT_MAX,
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};
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static int __init power_init(void)
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{
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unsigned long ret;
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unsigned long soft_power_reg;
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#if 0
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request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
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0, "powerfail", NULL);
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#endif
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/* enable the soft power switch if possible */
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ret = pdc_soft_power_info(&soft_power_reg);
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if (ret == PDC_OK)
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ret = pdc_soft_power_button(1);
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if (ret != PDC_OK)
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soft_power_reg = -1UL;
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switch (soft_power_reg) {
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case 0: printk(KERN_INFO DRIVER_NAME ": Gecko-style soft power switch enabled.\n");
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break;
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case -1UL: printk(KERN_INFO DRIVER_NAME ": Soft power switch support not available.\n");
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return -ENODEV;
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default: printk(KERN_INFO DRIVER_NAME ": Soft power switch at 0x%08lx enabled.\n",
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soft_power_reg);
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}
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power_task = kthread_run(kpowerswd, (void*)soft_power_reg, KTHREAD_NAME);
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if (IS_ERR(power_task)) {
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printk(KERN_ERR DRIVER_NAME ": thread creation failed. Driver not loaded.\n");
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pdc_soft_power_button(0);
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return -EIO;
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}
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/* Register a call for panic conditions. */
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atomic_notifier_chain_register(&panic_notifier_list,
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&parisc_panic_block);
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return 0;
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}
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static void __exit power_exit(void)
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{
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kthread_stop(power_task);
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atomic_notifier_chain_unregister(&panic_notifier_list,
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&parisc_panic_block);
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pdc_soft_power_button(0);
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}
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arch_initcall(power_init);
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module_exit(power_exit);
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MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
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MODULE_DESCRIPTION("Soft power switch driver");
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MODULE_LICENSE("Dual BSD/GPL");
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