[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / watchdog / pc87413_wdt.c

/*
 *      NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x
 *
 *      This code is based on wdt.c with original copyright.
 *
 *      (C) Copyright 2006 Sven Anders, <anders@anduras.de>
 *                     and Marcus Junker, <junker@anduras.de>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 *
 *      Neither Sven Anders, Marcus Junker nor ANDURAS AG
 *      admit liability nor provide warranty for any of this software.
 *      This material is provided "AS-IS" and at no charge.
 *
 *      Release 1.1
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/moduleparam.h>
#include <linux/io.h>
#include <linux/uaccess.h>


/* #define DEBUG 1 */

#define DEFAULT_TIMEOUT     1		/* 1 minute */
#define MAX_TIMEOUT         255

#define VERSION             "1.1"
#define MODNAME             "pc87413 WDT"
#define DPFX                MODNAME " - DEBUG: "

#define WDT_INDEX_IO_PORT   (io+0)	/* I/O port base (index register) */
#define WDT_DATA_IO_PORT    (WDT_INDEX_IO_PORT+1)
#define SWC_LDN             0x04
#define SIOCFG2             0x22	/* Serial IO register */
#define WDCTL               0x10	/* Watchdog-Timer-Control-Register */
#define WDTO                0x11	/* Watchdog timeout register */
#define WDCFG               0x12	/* Watchdog config register */

#define IO_DEFAULT	0x2E		/* Address used on Portwell Boards */

static int io = IO_DEFAULT;
static int swc_base_addr = -1;

static int timeout = DEFAULT_TIMEOUT;	/* timeout value */
static unsigned long timer_enabled;	/* is the timer enabled? */

static char expect_close;		/* is the close expected? */

static DEFINE_SPINLOCK(io_lock);	/* to guard us from io races */

static bool nowayout = WATCHDOG_NOWAYOUT;

/* -- Low level function ----------------------------------------*/

/* Select pins for Watchdog output */

static inline void pc87413_select_wdt_out(void)
{
	unsigned int cr_data = 0;

	/* Step 1: Select multiple pin,pin55,as WDT output */

	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);

	cr_data = inb(WDT_DATA_IO_PORT);

	cr_data |= 0x80; /* Set Bit7 to 1*/
	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);

	outb_p(cr_data, WDT_DATA_IO_PORT);

#ifdef DEBUG
	pr_info(DPFX
		"Select multiple pin,pin55,as WDT output: Bit7 to 1: %d\n",
								cr_data);
#endif
}

/* Enable SWC functions */

static inline void pc87413_enable_swc(void)
{
	unsigned int cr_data = 0;

	/* Step 2: Enable SWC functions */

	outb_p(0x07, WDT_INDEX_IO_PORT);	/* Point SWC_LDN (LDN=4) */
	outb_p(SWC_LDN, WDT_DATA_IO_PORT);

	outb_p(0x30, WDT_INDEX_IO_PORT);	/* Read Index 0x30 First */
	cr_data = inb(WDT_DATA_IO_PORT);
	cr_data |= 0x01;			/* Set Bit0 to 1 */
	outb_p(0x30, WDT_INDEX_IO_PORT);
	outb_p(cr_data, WDT_DATA_IO_PORT);	/* Index0x30_bit0P1 */

#ifdef DEBUG
	pr_info(DPFX "pc87413 - Enable SWC functions\n");
#endif
}

/* Read SWC I/O base address */

static void pc87413_get_swc_base_addr(void)
{
	unsigned char addr_l, addr_h = 0;

	/* Step 3: Read SWC I/O Base Address */

	outb_p(0x60, WDT_INDEX_IO_PORT);	/* Read Index 0x60 */
	addr_h = inb(WDT_DATA_IO_PORT);

	outb_p(0x61, WDT_INDEX_IO_PORT);	/* Read Index 0x61 */

	addr_l = inb(WDT_DATA_IO_PORT);

	swc_base_addr = (addr_h << 8) + addr_l;
#ifdef DEBUG
	pr_info(DPFX
		"Read SWC I/O Base Address: low %d, high %d, res %d\n",
						addr_l, addr_h, swc_base_addr);
#endif
}

/* Select Bank 3 of SWC */

static inline void pc87413_swc_bank3(void)
{
	/* Step 4: Select Bank3 of SWC */
	outb_p(inb(swc_base_addr + 0x0f) | 0x03, swc_base_addr + 0x0f);
#ifdef DEBUG
	pr_info(DPFX "Select Bank3 of SWC\n");
#endif
}

/* Set watchdog timeout to x minutes */

static inline void pc87413_programm_wdto(char pc87413_time)
{
	/* Step 5: Programm WDTO, Twd. */
	outb_p(pc87413_time, swc_base_addr + WDTO);
#ifdef DEBUG
	pr_info(DPFX "Set WDTO to %d minutes\n", pc87413_time);
#endif
}

/* Enable WDEN */

static inline void pc87413_enable_wden(void)
{
	/* Step 6: Enable WDEN */
	outb_p(inb(swc_base_addr + WDCTL) | 0x01, swc_base_addr + WDCTL);
#ifdef DEBUG
	pr_info(DPFX "Enable WDEN\n");
#endif
}

/* Enable SW_WD_TREN */
static inline void pc87413_enable_sw_wd_tren(void)
{
	/* Enable SW_WD_TREN */
	outb_p(inb(swc_base_addr + WDCFG) | 0x80, swc_base_addr + WDCFG);
#ifdef DEBUG
	pr_info(DPFX "Enable SW_WD_TREN\n");
#endif
}

/* Disable SW_WD_TREN */

static inline void pc87413_disable_sw_wd_tren(void)
{
	/* Disable SW_WD_TREN */
	outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
#ifdef DEBUG
	pr_info(DPFX "pc87413 - Disable SW_WD_TREN\n");
#endif
}

/* Enable SW_WD_TRG */

static inline void pc87413_enable_sw_wd_trg(void)
{
	/* Enable SW_WD_TRG */
	outb_p(inb(swc_base_addr + WDCTL) | 0x80, swc_base_addr + WDCTL);
#ifdef DEBUG
	pr_info(DPFX "pc87413 - Enable SW_WD_TRG\n");
#endif
}

/* Disable SW_WD_TRG */

static inline void pc87413_disable_sw_wd_trg(void)
{
	/* Disable SW_WD_TRG */
	outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
#ifdef DEBUG
	pr_info(DPFX "Disable SW_WD_TRG\n");
#endif
}

/* -- Higher level functions ------------------------------------*/

/* Enable the watchdog */

static void pc87413_enable(void)
{
	spin_lock(&io_lock);

	pc87413_swc_bank3();
	pc87413_programm_wdto(timeout);
	pc87413_enable_wden();
	pc87413_enable_sw_wd_tren();
	pc87413_enable_sw_wd_trg();

	spin_unlock(&io_lock);
}

/* Disable the watchdog */

static void pc87413_disable(void)
{
	spin_lock(&io_lock);

	pc87413_swc_bank3();
	pc87413_disable_sw_wd_tren();
	pc87413_disable_sw_wd_trg();
	pc87413_programm_wdto(0);

	spin_unlock(&io_lock);
}

/* Refresh the watchdog */

static void pc87413_refresh(void)
{
	spin_lock(&io_lock);

	pc87413_swc_bank3();
	pc87413_disable_sw_wd_tren();
	pc87413_disable_sw_wd_trg();
	pc87413_programm_wdto(timeout);
	pc87413_enable_wden();
	pc87413_enable_sw_wd_tren();
	pc87413_enable_sw_wd_trg();

	spin_unlock(&io_lock);
}

/* -- File operations -------------------------------------------*/

/**
 *	pc87413_open:
 *	@inode: inode of device
 *	@file: file handle to device
 *
 */

static int pc87413_open(struct inode *inode, struct file *file)
{
	/* /dev/watchdog can only be opened once */

	if (test_and_set_bit(0, &timer_enabled))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	/* Reload and activate timer */
	pc87413_refresh();

	pr_info("Watchdog enabled. Timeout set to %d minute(s).\n", timeout);

	return nonseekable_open(inode, file);
}

/**
 *	pc87413_release:
 *	@inode: inode to board
 *	@file: file handle to board
 *
 *	The watchdog has a configurable API. There is a religious dispute
 *	between people who want their watchdog to be able to shut down and
 *	those who want to be sure if the watchdog manager dies the machine
 *	reboots. In the former case we disable the counters, in the latter
 *	case you have to open it again very soon.
 */

static int pc87413_release(struct inode *inode, struct file *file)
{
	/* Shut off the timer. */

	if (expect_close == 42) {
		pc87413_disable();
		pr_info("Watchdog disabled, sleeping again...\n");
	} else {
		pr_crit("Unexpected close, not stopping watchdog!\n");
		pc87413_refresh();
	}
	clear_bit(0, &timer_enabled);
	expect_close = 0;
	return 0;
}

/**
 *	pc87413_status:
 *
 *      return, if the watchdog is enabled (timeout is set...)
 */


static int pc87413_status(void)
{
	  return 0; /* currently not supported */
}

/**
 *	pc87413_write:
 *	@file: file handle to the watchdog
 *	@data: data buffer to write
 *	@len: length in bytes
 *	@ppos: pointer to the position to write. No seeks allowed
 *
 *	A write to a watchdog device is defined as a keepalive signal. Any
 *	write of data will do, as we we don't define content meaning.
 */

static ssize_t pc87413_write(struct file *file, const char __user *data,
			     size_t len, loff_t *ppos)
{
	/* See if we got the magic character 'V' and reload the timer */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* reset expect flag */
			expect_close = 0;

			/* scan to see whether or not we got the
			   magic character */
			for (i = 0; i != len; i++) {
				char c;
				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}

		/* someone wrote to us, we should reload the timer */
		pc87413_refresh();
	}
	return len;
}

/**
 *	pc87413_ioctl:
 *	@file: file handle to the device
 *	@cmd: watchdog command
 *	@arg: argument pointer
 *
 *	The watchdog API defines a common set of functions for all watchdogs
 *	according to their available features. We only actually usefully support
 *	querying capabilities and current status.
 */

static long pc87413_ioctl(struct file *file, unsigned int cmd,
						unsigned long arg)
{
	int new_timeout;

	union {
		struct watchdog_info __user *ident;
		int __user *i;
	} uarg;

	static const struct watchdog_info ident = {
		.options          = WDIOF_KEEPALIVEPING |
				    WDIOF_SETTIMEOUT |
				    WDIOF_MAGICCLOSE,
		.firmware_version = 1,
		.identity         = "PC87413(HF/F) watchdog",
	};

	uarg.i = (int __user *)arg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(uarg.ident, &ident,
					sizeof(ident)) ? -EFAULT : 0;
	case WDIOC_GETSTATUS:
		return put_user(pc87413_status(), uarg.i);
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, uarg.i);
	case WDIOC_SETOPTIONS:
	{
		int options, retval = -EINVAL;
		if (get_user(options, uarg.i))
			return -EFAULT;
		if (options & WDIOS_DISABLECARD) {
			pc87413_disable();
			retval = 0;
		}
		if (options & WDIOS_ENABLECARD) {
			pc87413_enable();
			retval = 0;
		}
		return retval;
	}
	case WDIOC_KEEPALIVE:
		pc87413_refresh();
#ifdef DEBUG
		pr_info(DPFX "keepalive\n");
#endif
		return 0;
	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, uarg.i))
			return -EFAULT;
		/* the API states this is given in secs */
		new_timeout /= 60;
		if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
			return -EINVAL;
		timeout = new_timeout;
		pc87413_refresh();
		/* fall through and return the new timeout... */
	case WDIOC_GETTIMEOUT:
		new_timeout = timeout * 60;
		return put_user(new_timeout, uarg.i);
	default:
		return -ENOTTY;
	}
}

/* -- Notifier funtions -----------------------------------------*/

/**
 *	notify_sys:
 *	@this: our notifier block
 *	@code: the event being reported
 *	@unused: unused
 *
 *	Our notifier is called on system shutdowns. We want to turn the card
 *	off at reboot otherwise the machine will reboot again during memory
 *	test or worse yet during the following fsck. This would suck, in fact
 *	trust me - if it happens it does suck.
 */

static int pc87413_notify_sys(struct notifier_block *this,
			      unsigned long code,
			      void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		/* Turn the card off */
		pc87413_disable();
	return NOTIFY_DONE;
}

/* -- Module's structures ---------------------------------------*/

static const struct file_operations pc87413_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= pc87413_write,
	.unlocked_ioctl	= pc87413_ioctl,
	.open		= pc87413_open,
	.release	= pc87413_release,
};

static struct notifier_block pc87413_notifier = {
	.notifier_call  = pc87413_notify_sys,
};

static struct miscdevice pc87413_miscdev = {
	.minor          = WATCHDOG_MINOR,
	.name           = "watchdog",
	.fops           = &pc87413_fops,
};

/* -- Module init functions -------------------------------------*/

/**
 *	pc87413_init: module's "constructor"
 *
 *	Set up the WDT watchdog board. All we have to do is grab the
 *	resources we require and bitch if anyone beat us to them.
 *	The open() function will actually kick the board off.
 */

static int __init pc87413_init(void)
{
	int ret;

	pr_info("Version " VERSION " at io 0x%X\n",
							WDT_INDEX_IO_PORT);

	if (!request_muxed_region(io, 2, MODNAME))
		return -EBUSY;

	ret = register_reboot_notifier(&pc87413_notifier);
	if (ret != 0) {
		pr_err("cannot register reboot notifier (err=%d)\n", ret);
	}

	ret = misc_register(&pc87413_miscdev);
	if (ret != 0) {
		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
		       WATCHDOG_MINOR, ret);
		goto reboot_unreg;
	}
	pr_info("initialized. timeout=%d min\n", timeout);

	pc87413_select_wdt_out();
	pc87413_enable_swc();
	pc87413_get_swc_base_addr();

	if (!request_region(swc_base_addr, 0x20, MODNAME)) {
		pr_err("cannot request SWC region at 0x%x\n", swc_base_addr);
		ret = -EBUSY;
		goto misc_unreg;
	}

	pc87413_enable();

	release_region(io, 2);
	return 0;

misc_unreg:
	misc_deregister(&pc87413_miscdev);
reboot_unreg:
	unregister_reboot_notifier(&pc87413_notifier);
	release_region(io, 2);
	return ret;
}

/**
 *	pc87413_exit: module's "destructor"
 *
 *	Unload the watchdog. You cannot do this with any file handles open.
 *	If your watchdog is set to continue ticking on close and you unload
 *	it, well it keeps ticking. We won't get the interrupt but the board
 *	will not touch PC memory so all is fine. You just have to load a new
 *	module in 60 seconds or reboot.
 */

static void __exit pc87413_exit(void)
{
	/* Stop the timer before we leave */
	if (!nowayout) {
		pc87413_disable();
		pr_info("Watchdog disabled\n");
	}

	misc_deregister(&pc87413_miscdev);
	unregister_reboot_notifier(&pc87413_notifier);
	release_region(swc_base_addr, 0x20);

	pr_info("watchdog component driver removed\n");
}

module_init(pc87413_init);
module_exit(pc87413_exit);

MODULE_AUTHOR("Sven Anders <anders@anduras.de>, "
		"Marcus Junker <junker@anduras.de>,");
MODULE_DESCRIPTION("PC87413 WDT driver");
MODULE_LICENSE("GPL");

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

module_param(io, int, 0);
MODULE_PARM_DESC(io, MODNAME " I/O port (default: "
					__MODULE_STRING(IO_DEFAULT) ").");

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
		"Watchdog timeout in minutes (default="
				__MODULE_STRING(DEFAULT_TIMEOUT) ").");

module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Commit	Line	Data
	1	/*
	2	* NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x
	3	*
	4	* This code is based on wdt.c with original copyright.
	5	*
	6	* (C) Copyright 2006 Sven Anders, <anders@anduras.de>
	7	* and Marcus Junker, <junker@anduras.de>
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*
	14	* Neither Sven Anders, Marcus Junker nor ANDURAS AG
	15	* admit liability nor provide warranty for any of this software.
	16	* This material is provided "AS-IS" and at no charge.
	17	*
	18	* Release 1.1
	19	*/
	20
	21	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	22
	23	#include <linux/module.h>
	24	#include <linux/types.h>
	25	#include <linux/miscdevice.h>
	26	#include <linux/watchdog.h>
	27	#include <linux/ioport.h>
	28	#include <linux/delay.h>
	29	#include <linux/notifier.h>
	30	#include <linux/fs.h>
	31	#include <linux/reboot.h>
	32	#include <linux/init.h>
	33	#include <linux/spinlock.h>
	34	#include <linux/moduleparam.h>
	35	#include <linux/io.h>
	36	#include <linux/uaccess.h>
	37
	38
	39	/* #define DEBUG 1 */
	40
	41	#define DEFAULT_TIMEOUT 1 /* 1 minute */
	42	#define MAX_TIMEOUT 255
	43
	44	#define VERSION "1.1"
	45	#define MODNAME "pc87413 WDT"
	46	#define DPFX MODNAME " - DEBUG: "
	47
	48	#define WDT_INDEX_IO_PORT (io+0) /* I/O port base (index register) */
	49	#define WDT_DATA_IO_PORT (WDT_INDEX_IO_PORT+1)
	50	#define SWC_LDN 0x04
	51	#define SIOCFG2 0x22 /* Serial IO register */
	52	#define WDCTL 0x10 /* Watchdog-Timer-Control-Register */
	53	#define WDTO 0x11 /* Watchdog timeout register */
	54	#define WDCFG 0x12 /* Watchdog config register */
	55
	56	#define IO_DEFAULT 0x2E /* Address used on Portwell Boards */
	57
	58	static int io = IO_DEFAULT;
	59	static int swc_base_addr = -1;
	60
	61	static int timeout = DEFAULT_TIMEOUT; /* timeout value */
	62	static unsigned long timer_enabled; /* is the timer enabled? */
	63
	64	static char expect_close; /* is the close expected? */
	65
	66	static DEFINE_SPINLOCK(io_lock); /* to guard us from io races */
	67
	68	static bool nowayout = WATCHDOG_NOWAYOUT;
	69
	70	/* -- Low level function ----------------------------------------*/
	71
	72	/* Select pins for Watchdog output */
	73
	74	static inline void pc87413_select_wdt_out(void)
	75	{
	76	unsigned int cr_data = 0;
	77
	78	/* Step 1: Select multiple pin,pin55,as WDT output */
	79
	80	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
	81
	82	cr_data = inb(WDT_DATA_IO_PORT);
	83
	84	cr_data \|= 0x80; /* Set Bit7 to 1*/
	85	outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
	86
	87	outb_p(cr_data, WDT_DATA_IO_PORT);
	88
	89	#ifdef DEBUG
	90	pr_info(DPFX
	91	"Select multiple pin,pin55,as WDT output: Bit7 to 1: %d\n",
	92	cr_data);
	93	#endif
	94	}
	95
	96	/* Enable SWC functions */
	97
	98	static inline void pc87413_enable_swc(void)
	99	{
	100	unsigned int cr_data = 0;
	101
	102	/* Step 2: Enable SWC functions */
	103
	104	outb_p(0x07, WDT_INDEX_IO_PORT); /* Point SWC_LDN (LDN=4) */
	105	outb_p(SWC_LDN, WDT_DATA_IO_PORT);
	106
	107	outb_p(0x30, WDT_INDEX_IO_PORT); /* Read Index 0x30 First */
	108	cr_data = inb(WDT_DATA_IO_PORT);
	109	cr_data \|= 0x01; /* Set Bit0 to 1 */
	110	outb_p(0x30, WDT_INDEX_IO_PORT);
	111	outb_p(cr_data, WDT_DATA_IO_PORT); /* Index0x30_bit0P1 */
	112
	113	#ifdef DEBUG
	114	pr_info(DPFX "pc87413 - Enable SWC functions\n");
	115	#endif
	116	}
	117
	118	/* Read SWC I/O base address */
	119
	120	static void pc87413_get_swc_base_addr(void)
	121	{
	122	unsigned char addr_l, addr_h = 0;
	123
	124	/* Step 3: Read SWC I/O Base Address */
	125
	126	outb_p(0x60, WDT_INDEX_IO_PORT); /* Read Index 0x60 */
	127	addr_h = inb(WDT_DATA_IO_PORT);
	128
	129	outb_p(0x61, WDT_INDEX_IO_PORT); /* Read Index 0x61 */
	130
	131	addr_l = inb(WDT_DATA_IO_PORT);
	132
	133	swc_base_addr = (addr_h << 8) + addr_l;
	134	#ifdef DEBUG
	135	pr_info(DPFX
	136	"Read SWC I/O Base Address: low %d, high %d, res %d\n",
	137	addr_l, addr_h, swc_base_addr);
	138	#endif
	139	}
	140
	141	/* Select Bank 3 of SWC */
	142
	143	static inline void pc87413_swc_bank3(void)
	144	{
	145	/* Step 4: Select Bank3 of SWC */
	146	outb_p(inb(swc_base_addr + 0x0f) \| 0x03, swc_base_addr + 0x0f);
	147	#ifdef DEBUG
	148	pr_info(DPFX "Select Bank3 of SWC\n");
	149	#endif
	150	}
	151
	152	/* Set watchdog timeout to x minutes */
	153
	154	static inline void pc87413_programm_wdto(char pc87413_time)
	155	{
	156	/* Step 5: Programm WDTO, Twd. */
	157	outb_p(pc87413_time, swc_base_addr + WDTO);
	158	#ifdef DEBUG
	159	pr_info(DPFX "Set WDTO to %d minutes\n", pc87413_time);
	160	#endif
	161	}
	162
	163	/* Enable WDEN */
	164
	165	static inline void pc87413_enable_wden(void)
	166	{
	167	/* Step 6: Enable WDEN */
	168	outb_p(inb(swc_base_addr + WDCTL) \| 0x01, swc_base_addr + WDCTL);
	169	#ifdef DEBUG
	170	pr_info(DPFX "Enable WDEN\n");
	171	#endif
	172	}
	173
	174	/* Enable SW_WD_TREN */
	175	static inline void pc87413_enable_sw_wd_tren(void)
	176	{
	177	/* Enable SW_WD_TREN */
	178	outb_p(inb(swc_base_addr + WDCFG) \| 0x80, swc_base_addr + WDCFG);
	179	#ifdef DEBUG
	180	pr_info(DPFX "Enable SW_WD_TREN\n");
	181	#endif
	182	}
	183
	184	/* Disable SW_WD_TREN */
	185
	186	static inline void pc87413_disable_sw_wd_tren(void)
	187	{
	188	/* Disable SW_WD_TREN */
	189	outb_p(inb(swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
	190	#ifdef DEBUG
	191	pr_info(DPFX "pc87413 - Disable SW_WD_TREN\n");
	192	#endif
	193	}
	194
	195	/* Enable SW_WD_TRG */
	196
	197	static inline void pc87413_enable_sw_wd_trg(void)
	198	{
	199	/* Enable SW_WD_TRG */
	200	outb_p(inb(swc_base_addr + WDCTL) \| 0x80, swc_base_addr + WDCTL);
	201	#ifdef DEBUG
	202	pr_info(DPFX "pc87413 - Enable SW_WD_TRG\n");
	203	#endif
	204	}
	205
	206	/* Disable SW_WD_TRG */
	207
	208	static inline void pc87413_disable_sw_wd_trg(void)
	209	{
	210	/* Disable SW_WD_TRG */
	211	outb_p(inb(swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
	212	#ifdef DEBUG
	213	pr_info(DPFX "Disable SW_WD_TRG\n");
	214	#endif
	215	}
	216
	217	/* -- Higher level functions ------------------------------------*/
	218
	219	/* Enable the watchdog */
	220
	221	static void pc87413_enable(void)
	222	{
	223	spin_lock(&io_lock);
	224
	225	pc87413_swc_bank3();
	226	pc87413_programm_wdto(timeout);
	227	pc87413_enable_wden();
	228	pc87413_enable_sw_wd_tren();
	229	pc87413_enable_sw_wd_trg();
	230
	231	spin_unlock(&io_lock);
	232	}
	233
	234	/* Disable the watchdog */
	235
	236	static void pc87413_disable(void)
	237	{
	238	spin_lock(&io_lock);
	239
	240	pc87413_swc_bank3();
	241	pc87413_disable_sw_wd_tren();
	242	pc87413_disable_sw_wd_trg();
	243	pc87413_programm_wdto(0);
	244
	245	spin_unlock(&io_lock);
	246	}
	247
	248	/* Refresh the watchdog */
	249
	250	static void pc87413_refresh(void)
	251	{
	252	spin_lock(&io_lock);
	253
	254	pc87413_swc_bank3();
	255	pc87413_disable_sw_wd_tren();
	256	pc87413_disable_sw_wd_trg();
	257	pc87413_programm_wdto(timeout);
	258	pc87413_enable_wden();
	259	pc87413_enable_sw_wd_tren();
	260	pc87413_enable_sw_wd_trg();
	261
	262	spin_unlock(&io_lock);
	263	}
	264
	265	/* -- File operations -------------------------------------------*/
	266
	267	/**
	268	* pc87413_open:
	269	* @inode: inode of device
	270	* @file: file handle to device
	271	*
	272	*/
	273
	274	static int pc87413_open(struct inode inode, struct file file)
	275	{
	276	/* /dev/watchdog can only be opened once */
	277
	278	if (test_and_set_bit(0, &timer_enabled))
	279	return -EBUSY;
	280
	281	if (nowayout)
	282	__module_get(THIS_MODULE);
	283
	284	/* Reload and activate timer */
	285	pc87413_refresh();
	286
	287	pr_info("Watchdog enabled. Timeout set to %d minute(s).\n", timeout);
	288
	289	return nonseekable_open(inode, file);
	290	}
	291
	292	/**
	293	* pc87413_release:
	294	* @inode: inode to board
	295	* @file: file handle to board
	296	*
	297	* The watchdog has a configurable API. There is a religious dispute
	298	* between people who want their watchdog to be able to shut down and
	299	* those who want to be sure if the watchdog manager dies the machine
	300	* reboots. In the former case we disable the counters, in the latter
	301	* case you have to open it again very soon.
	302	*/
	303
	304	static int pc87413_release(struct inode inode, struct file file)
	305	{
	306	/* Shut off the timer. */
	307
	308	if (expect_close == 42) {
	309	pc87413_disable();
	310	pr_info("Watchdog disabled, sleeping again...\n");
	311	} else {
	312	pr_crit("Unexpected close, not stopping watchdog!\n");
	313	pc87413_refresh();
	314	}
	315	clear_bit(0, &timer_enabled);
	316	expect_close = 0;
	317	return 0;
	318	}
	319
	320	/**
	321	* pc87413_status:
	322	*
	323	* return, if the watchdog is enabled (timeout is set...)
	324	*/
	325
	326
	327	static int pc87413_status(void)
	328	{
	329	return 0; /* currently not supported */
	330	}
	331
	332	/**
	333	* pc87413_write:
	334	* @file: file handle to the watchdog
	335	* @data: data buffer to write
	336	* @len: length in bytes
	337	* @ppos: pointer to the position to write. No seeks allowed
	338	*
	339	* A write to a watchdog device is defined as a keepalive signal. Any
	340	* write of data will do, as we we don't define content meaning.
	341	*/
	342
	343	static ssize_t pc87413_write(struct file file, const char __user data,
	344	size_t len, loff_t *ppos)
	345	{
	346	/* See if we got the magic character 'V' and reload the timer */
	347	if (len) {
	348	if (!nowayout) {
	349	size_t i;
	350
	351	/* reset expect flag */
	352	expect_close = 0;
	353
	354	/* scan to see whether or not we got the
	355	magic character */
	356	for (i = 0; i != len; i++) {
	357	char c;
	358	if (get_user(c, data + i))
	359	return -EFAULT;
	360	if (c == 'V')
	361	expect_close = 42;
	362	}
	363	}
	364
	365	/* someone wrote to us, we should reload the timer */
	366	pc87413_refresh();
	367	}
	368	return len;
	369	}
	370
	371	/**
	372	* pc87413_ioctl:
	373	* @file: file handle to the device
	374	* @cmd: watchdog command
	375	* @arg: argument pointer
	376	*
	377	* The watchdog API defines a common set of functions for all watchdogs
	378	* according to their available features. We only actually usefully support
	379	* querying capabilities and current status.
	380	*/
	381
	382	static long pc87413_ioctl(struct file *file, unsigned int cmd,
	383	unsigned long arg)
	384	{
	385	int new_timeout;
	386
	387	union {
	388	struct watchdog_info __user *ident;
	389	int __user *i;
	390	} uarg;
	391
	392	static const struct watchdog_info ident = {
	393	.options = WDIOF_KEEPALIVEPING \|
	394	WDIOF_SETTIMEOUT \|
	395	WDIOF_MAGICCLOSE,
	396	.firmware_version = 1,
	397	.identity = "PC87413(HF/F) watchdog",
	398	};
	399
	400	uarg.i = (int __user *)arg;
	401
	402	switch (cmd) {
	403	case WDIOC_GETSUPPORT:
	404	return copy_to_user(uarg.ident, &ident,
	405	sizeof(ident)) ? -EFAULT : 0;
	406	case WDIOC_GETSTATUS:
	407	return put_user(pc87413_status(), uarg.i);
	408	case WDIOC_GETBOOTSTATUS:
	409	return put_user(0, uarg.i);
	410	case WDIOC_SETOPTIONS:
	411	{
	412	int options, retval = -EINVAL;
	413	if (get_user(options, uarg.i))
	414	return -EFAULT;
	415	if (options & WDIOS_DISABLECARD) {
	416	pc87413_disable();
	417	retval = 0;
	418	}
	419	if (options & WDIOS_ENABLECARD) {
	420	pc87413_enable();
	421	retval = 0;
	422	}
	423	return retval;
	424	}
	425	case WDIOC_KEEPALIVE:
	426	pc87413_refresh();
	427	#ifdef DEBUG
	428	pr_info(DPFX "keepalive\n");
	429	#endif
	430	return 0;
	431	case WDIOC_SETTIMEOUT:
	432	if (get_user(new_timeout, uarg.i))
	433	return -EFAULT;
	434	/* the API states this is given in secs */
	435	new_timeout /= 60;
	436	if (new_timeout < 0 \|\| new_timeout > MAX_TIMEOUT)
	437	return -EINVAL;
	438	timeout = new_timeout;
	439	pc87413_refresh();
	440	/* fall through and return the new timeout... */
	441	case WDIOC_GETTIMEOUT:
	442	new_timeout = timeout * 60;
	443	return put_user(new_timeout, uarg.i);
	444	default:
	445	return -ENOTTY;
	446	}
	447	}
	448
	449	/* -- Notifier funtions -----------------------------------------*/
	450
	451	/**
	452	* notify_sys:
	453	* @this: our notifier block
	454	* @code: the event being reported
	455	* @unused: unused
	456	*
	457	* Our notifier is called on system shutdowns. We want to turn the card
	458	* off at reboot otherwise the machine will reboot again during memory
	459	* test or worse yet during the following fsck. This would suck, in fact
	460	* trust me - if it happens it does suck.
	461	*/
	462
	463	static int pc87413_notify_sys(struct notifier_block *this,
	464	unsigned long code,
	465	void *unused)
	466	{
	467	if (code == SYS_DOWN \|\| code == SYS_HALT)
	468	/* Turn the card off */
	469	pc87413_disable();
	470	return NOTIFY_DONE;
	471	}
	472
	473	/* -- Module's structures ---------------------------------------*/
	474
	475	static const struct file_operations pc87413_fops = {
	476	.owner = THIS_MODULE,
	477	.llseek = no_llseek,
	478	.write = pc87413_write,
	479	.unlocked_ioctl = pc87413_ioctl,
	480	.open = pc87413_open,
	481	.release = pc87413_release,
	482	};
	483
	484	static struct notifier_block pc87413_notifier = {
	485	.notifier_call = pc87413_notify_sys,
	486	};
	487
	488	static struct miscdevice pc87413_miscdev = {
	489	.minor = WATCHDOG_MINOR,
	490	.name = "watchdog",
	491	.fops = &pc87413_fops,
	492	};
	493
	494	/* -- Module init functions -------------------------------------*/
	495
	496	/**
	497	* pc87413_init: module's "constructor"
	498	*
	499	* Set up the WDT watchdog board. All we have to do is grab the
	500	* resources we require and bitch if anyone beat us to them.
	501	* The open() function will actually kick the board off.
	502	*/
	503
	504	static int __init pc87413_init(void)
	505	{
	506	int ret;
	507
	508	pr_info("Version " VERSION " at io 0x%X\n",
	509	WDT_INDEX_IO_PORT);
	510
	511	if (!request_muxed_region(io, 2, MODNAME))
	512	return -EBUSY;
	513
	514	ret = register_reboot_notifier(&pc87413_notifier);
	515	if (ret != 0) {
	516	pr_err("cannot register reboot notifier (err=%d)\n", ret);
	517	}
	518
	519	ret = misc_register(&pc87413_miscdev);
	520	if (ret != 0) {
	521	pr_err("cannot register miscdev on minor=%d (err=%d)\n",
	522	WATCHDOG_MINOR, ret);
	523	goto reboot_unreg;
	524	}
	525	pr_info("initialized. timeout=%d min\n", timeout);
	526
	527	pc87413_select_wdt_out();
	528	pc87413_enable_swc();
	529	pc87413_get_swc_base_addr();
	530
	531	if (!request_region(swc_base_addr, 0x20, MODNAME)) {
	532	pr_err("cannot request SWC region at 0x%x\n", swc_base_addr);
	533	ret = -EBUSY;
	534	goto misc_unreg;
	535	}
	536
	537	pc87413_enable();
	538
	539	release_region(io, 2);
	540	return 0;
	541
	542	misc_unreg:
	543	misc_deregister(&pc87413_miscdev);
	544	reboot_unreg:
	545	unregister_reboot_notifier(&pc87413_notifier);
	546	release_region(io, 2);
	547	return ret;
	548	}
	549
	550	/**
	551	* pc87413_exit: module's "destructor"
	552	*
	553	* Unload the watchdog. You cannot do this with any file handles open.
	554	* If your watchdog is set to continue ticking on close and you unload
	555	* it, well it keeps ticking. We won't get the interrupt but the board
	556	* will not touch PC memory so all is fine. You just have to load a new
	557	* module in 60 seconds or reboot.
	558	*/
	559
	560	static void __exit pc87413_exit(void)
	561	{
	562	/* Stop the timer before we leave */
	563	if (!nowayout) {
	564	pc87413_disable();
	565	pr_info("Watchdog disabled\n");
	566	}
	567
	568	misc_deregister(&pc87413_miscdev);
	569	unregister_reboot_notifier(&pc87413_notifier);
	570	release_region(swc_base_addr, 0x20);
	571
	572	pr_info("watchdog component driver removed\n");
	573	}
	574
	575	module_init(pc87413_init);
	576	module_exit(pc87413_exit);
	577
	578	MODULE_AUTHOR("Sven Anders <anders@anduras.de>, "
	579	"Marcus Junker <junker@anduras.de>,");
	580	MODULE_DESCRIPTION("PC87413 WDT driver");
	581	MODULE_LICENSE("GPL");
	582
	583	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	584
	585	module_param(io, int, 0);
	586	MODULE_PARM_DESC(io, MODNAME " I/O port (default: "
	587	__MODULE_STRING(IO_DEFAULT) ").");
	588
	589	module_param(timeout, int, 0);
	590	MODULE_PARM_DESC(timeout,
	591	"Watchdog timeout in minutes (default="
	592	__MODULE_STRING(DEFAULT_TIMEOUT) ").");
	593
	594	module_param(nowayout, bool, 0);
	595	MODULE_PARM_DESC(nowayout,
	596	"Watchdog cannot be stopped once started (default="
	597	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	598