watchdog: remove bfin_wdt driver

nowayout: Watchdog cannot be stopped once started

	(default=kernel config parameter)

-------------------------------------------------

bfin_wdt:

timeout: Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=20)

nowayout: Watchdog cannot be stopped once started

	(default=kernel config parameter)

-------------------------------------------------

coh901327_wdt:

margin: Watchdog margin in seconds (default 60s)

-------------------------------------------------

	  Say Y here to include watchdog timer supported

	  by Spreadtrum system.

# BLACKFIN Architecture

config BFIN_WDT

	tristate "Blackfin On-Chip Watchdog Timer"

	depends on BLACKFIN

	---help---

	  If you say yes here you will get support for the Blackfin On-Chip

	  Watchdog Timer. If you have one of these processors and wish to

	  have watchdog support enabled, say Y, otherwise say N.

	  To compile this driver as a module, choose M here: the

	  module will be called bfin_wdt.

# X86 (i386 + ia64 + x86_64) Architecture

config ACQUIRE_WDT

obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o

obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o

# BLACKFIN Architecture

obj-$(CONFIG_BFIN_WDT) += bfin_wdt.o

# X86 (i386 + ia64 + x86_64) Architecture

obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o

obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o

/*

 * Blackfin On-Chip Watchdog Driver

 *

 * Originally based on softdog.c

 * Copyright 2006-2010 Analog Devices Inc.

 * Copyright 2006-2007 Michele d'Amico

 * Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>

 *

 * Enter bugs at http://blackfin.uclinux.org/

 *

 * Licensed under the GPL-2 or later.

 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/platform_device.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/types.h>

#include <linux/timer.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <linux/fs.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/uaccess.h>

#include <asm/blackfin.h>

#include <asm/bfin_watchdog.h>

#define stamp(fmt, args...) \

	pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)

#define stampit() stamp("here i am")

#define WATCHDOG_NAME "bfin-wdt"

/* The BF561 has two watchdogs (one per core), but since Linux

 * only runs on core A, we'll just work with that one.

 */

#ifdef BF561_FAMILY

# define bfin_read_WDOG_CTL()    bfin_read_WDOGA_CTL()

# define bfin_read_WDOG_CNT()    bfin_read_WDOGA_CNT()

# define bfin_read_WDOG_STAT()   bfin_read_WDOGA_STAT()

# define bfin_write_WDOG_CTL(x)  bfin_write_WDOGA_CTL(x)

# define bfin_write_WDOG_CNT(x)  bfin_write_WDOGA_CNT(x)

# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)

#endif

/* some defaults */

#define WATCHDOG_TIMEOUT 20

static unsigned int timeout = WATCHDOG_TIMEOUT;

static bool nowayout = WATCHDOG_NOWAYOUT;

static const struct watchdog_info bfin_wdt_info;

static unsigned long open_check;

static char expect_close;

static DEFINE_SPINLOCK(bfin_wdt_spinlock);

/**

 *	bfin_wdt_keepalive - Keep the Userspace Watchdog Alive

 *

 *	The Userspace watchdog got a KeepAlive: schedule the next timeout.

 */

static int bfin_wdt_keepalive(void)

{

	stampit();

	bfin_write_WDOG_STAT(0);

	return 0;

}

/**

 *	bfin_wdt_stop - Stop the Watchdog

 *

 *	Stops the on-chip watchdog.

 */

static int bfin_wdt_stop(void)

{

	stampit();

	bfin_write_WDOG_CTL(WDEN_DISABLE);

	return 0;

}

/**

 *	bfin_wdt_start - Start the Watchdog

 *

 *	Starts the on-chip watchdog.  Automatically loads WDOG_CNT

 *	into WDOG_STAT for us.

 */

static int bfin_wdt_start(void)

{

	stampit();

	bfin_write_WDOG_CTL(WDEN_ENABLE | ICTL_RESET);

	return 0;

}

/**

 *	bfin_wdt_running - Check Watchdog status

 *

 *	See if the watchdog is running.

 */

static int bfin_wdt_running(void)

{

	stampit();

	return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);

}

/**

 *	bfin_wdt_set_timeout - Set the Userspace Watchdog timeout

 *	@t: new timeout value (in seconds)

 *

 *	Translate the specified timeout in seconds into System Clock

 *	terms which is what the on-chip Watchdog requires.

 */

static int bfin_wdt_set_timeout(unsigned long t)

{

	u32 cnt, max_t, sclk;

	unsigned long flags;

	sclk = get_sclk();

	max_t = -1 / sclk;

	cnt = t * sclk;

	stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt);

	if (t > max_t) {

		pr_warn("timeout value is too large\n");

		return -EINVAL;

	}

	spin_lock_irqsave(&bfin_wdt_spinlock, flags);

	{

		int run = bfin_wdt_running();

		bfin_wdt_stop();

		bfin_write_WDOG_CNT(cnt);

		if (run)

			bfin_wdt_start();

	}

	spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);

	timeout = t;

	return 0;

}

/**

 *	bfin_wdt_open - Open the Device

 *	@inode: inode of device

 *	@file: file handle of device

 *

 *	Watchdog device is opened and started.

 */

static int bfin_wdt_open(struct inode *inode, struct file *file)

{

	stampit();

	if (test_and_set_bit(0, &open_check))

		return -EBUSY;

	if (nowayout)

		__module_get(THIS_MODULE);

	bfin_wdt_keepalive();

	bfin_wdt_start();

	return nonseekable_open(inode, file);

}

/**

 *	bfin_wdt_close - Close the Device

 *	@inode: inode of device

 *	@file: file handle of device

 *

 *	Watchdog device is closed and stopped.

 */

static int bfin_wdt_release(struct inode *inode, struct file *file)

{

	stampit();

	if (expect_close == 42)

		bfin_wdt_stop();

	else {

		pr_crit("Unexpected close, not stopping watchdog!\n");

		bfin_wdt_keepalive();

	}

	expect_close = 0;

	clear_bit(0, &open_check);

	return 0;

}

/**

 *	bfin_wdt_write - Write to Device

 *	@file: file handle of device

 *	@buf: buffer to write

 *	@count: length of buffer

 *	@ppos: offset

 *

 *	Pings the watchdog on write.

 */

static ssize_t bfin_wdt_write(struct file *file, const char __user *data,

						size_t len, loff_t *ppos)

{

	stampit();

	if (len) {

		if (!nowayout) {

			size_t i;

			/* In case it was set long ago */

			expect_close = 0;

			for (i = 0; i != len; i++) {

				char c;

				if (get_user(c, data + i))

					return -EFAULT;

				if (c == 'V')

					expect_close = 42;

			}

		}

		bfin_wdt_keepalive();

	}

	return len;

}

/**

 *	bfin_wdt_ioctl - Query Device

 *	@file: file handle of device

 *	@cmd: watchdog command

 *	@arg: argument

 *

 *	Query basic information from the device or ping it, as outlined by the

 *	watchdog API.

 */

static long bfin_wdt_ioctl(struct file *file,

				unsigned int cmd, unsigned long arg)

{

	void __user *argp = (void __user *)arg;

	int __user *p = argp;

	stampit();

	switch (cmd) {

	case WDIOC_GETSUPPORT:

		if (copy_to_user(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))

			return -EFAULT;

		else

			return 0;

	case WDIOC_GETSTATUS:

	case WDIOC_GETBOOTSTATUS:

		return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);

	case WDIOC_SETOPTIONS: {

		unsigned long flags;

		int options, ret = -EINVAL;

		if (get_user(options, p))

			return -EFAULT;

		spin_lock_irqsave(&bfin_wdt_spinlock, flags);

		if (options & WDIOS_DISABLECARD) {

			bfin_wdt_stop();

			ret = 0;

		}

		if (options & WDIOS_ENABLECARD) {

			bfin_wdt_start();

			ret = 0;

		}

		spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);

		return ret;

	}

	case WDIOC_KEEPALIVE:

		bfin_wdt_keepalive();

		return 0;

	case WDIOC_SETTIMEOUT: {

		int new_timeout;

		if (get_user(new_timeout, p))

			return -EFAULT;

		if (bfin_wdt_set_timeout(new_timeout))

			return -EINVAL;

	}

	/* Fall */

	case WDIOC_GETTIMEOUT:

		return put_user(timeout, p);

	default:

		return -ENOTTY;

	}

}

#ifdef CONFIG_PM

static int state_before_suspend;

/**

 *	bfin_wdt_suspend - suspend the watchdog

 *	@pdev: device being suspended

 *	@state: requested suspend state

 *

 *	Remember if the watchdog was running and stop it.

 *	TODO: is this even right?  Doesn't seem to be any

 *	      standard in the watchdog world ...

 */

static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)

{

	stampit();

	state_before_suspend = bfin_wdt_running();

	bfin_wdt_stop();

	return 0;

}

/**

 *	bfin_wdt_resume - resume the watchdog

 *	@pdev: device being resumed

 *

 *	If the watchdog was running, turn it back on.

 */

static int bfin_wdt_resume(struct platform_device *pdev)

{

	stampit();

	if (state_before_suspend) {

		bfin_wdt_set_timeout(timeout);

		bfin_wdt_start();

	}

	return 0;

}

#else

# define bfin_wdt_suspend NULL

# define bfin_wdt_resume NULL

#endif

static const struct file_operations bfin_wdt_fops = {

	.owner		= THIS_MODULE,

	.llseek		= no_llseek,

	.write		= bfin_wdt_write,

	.unlocked_ioctl	= bfin_wdt_ioctl,

	.open		= bfin_wdt_open,

	.release	= bfin_wdt_release,

};

static struct miscdevice bfin_wdt_miscdev = {

	.minor    = WATCHDOG_MINOR,

	.name     = "watchdog",

	.fops     = &bfin_wdt_fops,

};

static const struct watchdog_info bfin_wdt_info = {

	.identity = "Blackfin Watchdog",

	.options  = WDIOF_SETTIMEOUT |

		    WDIOF_KEEPALIVEPING |

		    WDIOF_MAGICCLOSE,

};

/**

 *	bfin_wdt_probe - Initialize module

 *

 *	Registers the misc device.  Actual device

 *	initialization is handled by bfin_wdt_open().

 */

static int bfin_wdt_probe(struct platform_device *pdev)

{

	int ret;

	ret = misc_register(&bfin_wdt_miscdev);

	if (ret) {

		pr_err("cannot register miscdev on minor=%d (err=%d)\n",

		       WATCHDOG_MINOR, ret);

		return ret;

	}

	pr_info("initialized: timeout=%d sec (nowayout=%d)\n",

		timeout, nowayout);

	return 0;

}

/**

 *	bfin_wdt_remove - Initialize module

 *

 *	Unregisters the misc device.  Actual device

 *	deinitialization is handled by bfin_wdt_close().

 */

static int bfin_wdt_remove(struct platform_device *pdev)

{

	misc_deregister(&bfin_wdt_miscdev);

	return 0;

}

/**

 *	bfin_wdt_shutdown - Soft Shutdown Handler

 *

 *	Handles the soft shutdown event.

 */

static void bfin_wdt_shutdown(struct platform_device *pdev)

{

	stampit();

	bfin_wdt_stop();

}

static struct platform_device *bfin_wdt_device;

static struct platform_driver bfin_wdt_driver = {

	.probe     = bfin_wdt_probe,

	.remove    = bfin_wdt_remove,

	.shutdown  = bfin_wdt_shutdown,

	.suspend   = bfin_wdt_suspend,

	.resume    = bfin_wdt_resume,

	.driver    = {

		.name  = WATCHDOG_NAME,

	},

};

/**

 *	bfin_wdt_init - Initialize module

 *

 *	Checks the module params and registers the platform device & driver.

 *	Real work is in the platform probe function.

 */

static int __init bfin_wdt_init(void)

{

	int ret;

	stampit();

	/* Check that the timeout value is within range */

	if (bfin_wdt_set_timeout(timeout))

		return -EINVAL;

	/* Since this is an on-chip device and needs no board-specific

	 * resources, we'll handle all the platform device stuff here.

	 */

	ret = platform_driver_register(&bfin_wdt_driver);

	if (ret) {

		pr_err("unable to register driver\n");

		return ret;

	}

	bfin_wdt_device = platform_device_register_simple(WATCHDOG_NAME,

								-1, NULL, 0);

	if (IS_ERR(bfin_wdt_device)) {

		pr_err("unable to register device\n");

		platform_driver_unregister(&bfin_wdt_driver);

		return PTR_ERR(bfin_wdt_device);

	}

	return 0;

}

/**

 *	bfin_wdt_exit - Deinitialize module

 *

 *	Back out the platform device & driver steps.  Real work is in the

 *	platform remove function.

 */

static void __exit bfin_wdt_exit(void)

{

	platform_device_unregister(bfin_wdt_device);

	platform_driver_unregister(&bfin_wdt_driver);

}

module_init(bfin_wdt_init);

module_exit(bfin_wdt_exit);

MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");

MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");

MODULE_LICENSE("GPL");

module_param(timeout, uint, 0);

MODULE_PARM_DESC(timeout,

	"Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default="

		__MODULE_STRING(WATCHDOG_TIMEOUT) ")");

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout,

	"Watchdog cannot be stopped once started (default="

		__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");