/*
* linux/arch/parisc/kernel/power.c
* HP PARISC soft power switch support driver
*
* Copyright (c) 2001-2005 Helge Deller <deller@gmx.de>
* All rights reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL").
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
*
*
*
* HINT:
* Support of the soft power switch button may be enabled or disabled at
* runtime through the "/proc/sys/kernel/power" procfs entry.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <asm/pdc.h>
#include <asm/io.h>
#include <asm/led.h>
#include <asm/uaccess.h>
#ifdef DEBUG
# define DPRINTK(x...) printk(x)
#else
# define DPRINTK(x...)
#endif
/* filename in /proc which can be used to enable/disable the power switch */
#define SYSCTL_FILENAME "sys/kernel/power"
#define DIAG_CODE(code) (0x14000000 + ((code)<<5))
/* this will go to processor.h or any other place... */
/* taken from PCXL ERS page 82 */
#define MFCPU_X(rDiagReg, t_ch, t_th, code) \
(DIAG_CODE(code) + ((rDiagReg)<<21) + ((t_ch)<<16) + ((t_th)<<0) )
#define MTCPU(dr, gr) MFCPU_X(dr, gr, 0, 0x12) /* move value of gr to dr[dr] */
#define MFCPU_C(dr, gr) MFCPU_X(dr, gr, 0, 0x30) /* for dr0 and dr8 only ! */
#define MFCPU_T(dr, gr) MFCPU_X(dr, 0, gr, 0xa0) /* all dr except dr0 and dr8 */
#define __getDIAG(dr) ( { \
register unsigned long __res asm("r28");\
__asm__ __volatile__ ( \
".word %1\n nop\n" : "=&r" (__res) : "i" (MFCPU_T(dr,28)) \
); \
__res; \
} )
static void deferred_poweroff(void *dummy)
{
extern int cad_pid; /* from kernel/sys.c */
if (kill_proc(cad_pid, SIGINT, 1)) {
/* just in case killing init process failed */
machine_power_off();
}
}
/*
* This function gets called from interrupt context.
* As it's called within an interrupt, it wouldn't sync if we don't
* use schedule_work().
*/
static DECLARE_WORK(poweroff_work, deferred_poweroff, NULL);
static void poweroff(void)
{
static int powering_off __read_mostly;
if (powering_off)
return;
powering_off++;
schedule_work(&poweroff_work);
}
/* local time-counter for shutdown */
static int shutdown_timer __read_mostly;
/* check, give feedback and start shutdown after one second */
static void process_shutdown(void)
{
if (shutdown_timer == 0)
DPRINTK(KERN_INFO "Shutdown requested...\n");
shutdown_timer++;
/* wait until the button was pressed for 1 second */
if (shutdown_timer == HZ) {
#if defined (DEBUG) || defined(CONFIG_CHASSIS_LCD_LED)
static char msg[] = "Shutting down...";
#endif
DPRINTK(KERN_INFO "%s\n", msg);
lcd_print(msg);
poweroff();
}
}
/* main power switch tasklet struct (scheduled from time.c) */
DECLARE_TASKLET_DISABLED(power_tasklet, NULL, 0);
/* soft power switch enabled/disabled */
int pwrsw_enabled __read_mostly = 1;
/*
* On gecko style machines (e.g. 712/xx and 715/xx)
* the power switch status is stored in Bit 0 ("the highest bit")
* of CPU diagnose register 25.
*
*/
static void gecko_tasklet_func(unsigned long unused)
{
if (unlikely(!pwrsw_enabled))
return;
if (__getDIAG(25) & 0x80000000) {
/* power switch button not pressed or released again */
/* Warning: Some machines do never reset this DIAG flag! */
shutdown_timer = 0;
} else {
process_shutdown();
}
}
/*
* Check the power switch status which is read from the
* real I/O location at soft_power_reg.
* Bit 31 ("the lowest bit) is the status of the power switch.
*/
static void polling_tasklet_func(unsigned long soft_power_reg)
{
unsigned long current_status;
if (unlikely(!pwrsw_enabled))
return;
current_status = gsc_readl(soft_power_reg);
if (current_status & 0x1) {
/* power switch button not pressed */
shutdown_timer = 0;
} else {
process_shutdown();
}
}
/*
* powerfail interruption handler (irq IRQ_FROM_REGION(CPU_IRQ_REGION)+2)
*/
#if 0
static void powerfail_interrupt(int code, void *x, struct pt_regs *regs)
{
printk(KERN_CRIT "POWERFAIL INTERRUPTION !\n");
poweroff();
}
#endif
/* parisc_panic_event() is called by the panic handler.
* As soon as a panic occurs, our tasklets above will not be
* executed any longer. This function then re-enables the
* soft-power switch and allows the user to switch off the system
*/
static int parisc_panic_event(struct notifier_block *this,
unsigned long event, void *ptr)
{
/* re-enable the soft-power switch */
pdc_soft_power_button(0);
return NOTIFY_DONE;
}
static struct notifier_block parisc_panic_block = {
.notifier_call = parisc_panic_event,
.priority = INT_MAX,
};
static int __init power_init(void)
{
unsigned long ret;
unsigned long soft_power_reg = 0;
#if 0
request_irq( IRQ_FROM_REGION(CPU_IRQ_REGION)+2, &powerfail_interrupt,
0, "powerfail", NULL);
#endif
/* enable the soft power switch if possible */
ret = pdc_soft_power_info(&soft_power_reg);
if (ret == PDC_OK)
ret = pdc_soft_power_button(1);
if (ret != PDC_OK)
soft_power_reg = -1UL;
switch (soft_power_reg) {
case 0: printk(KERN_INFO "Gecko-style soft power switch enabled.\n");
power_tasklet.func = gecko_tasklet_func;
break;
case -1UL: printk(KERN_INFO "Soft power switch support not available.\n");
return -ENODEV;
default: printk(KERN_INFO "Soft power switch enabled, polling @ 0x%08lx.\n",
soft_power_reg);
power_tasklet.data = soft_power_reg;
power_tasklet.func = polling_tasklet_func;
}
/* Register a call for panic conditions. */
atomic_notifier_chain_register(&panic_notifier_list,
&parisc_panic_block);
tasklet_enable(&power_tasklet);
return 0;
}
static void __exit power_exit(void)
{
if (!power_tasklet.func)
return;
tasklet_disable(&power_tasklet);
atomic_notifier_chain_unregister(&panic_notifier_list,
&parisc_panic_block);
power_tasklet.func = NULL;
pdc_soft_power_button(0);
}
module_init(power_init);
module_exit(power_exit);
MODULE_AUTHOR("Helge Deller");
MODULE_DESCRIPTION("Soft power switch driver");
MODULE_LICENSE("Dual BSD/GPL");
