/* * Watchdog driver for Kendin/Micrel KS8695. * * (C) 2007 Andrew Victor * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */#include <linux/bitops.h>#include <linux/errno.h>#include <linux/fs.h>#include <linux/init.h>#include <linux/kernel.h>#include <linux/miscdevice.h>#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/platform_device.h>#include <linux/types.h>#include <linux/watchdog.h>#include <asm/io.h>#include <asm/uaccess.h>#include <asm/arch/regs-timer.h>#define WDT_DEFAULT_TIME	5	/* seconds */#define WDT_MAX_TIME		171	/* seconds */static int wdt_time = WDT_DEFAULT_TIME;static int nowayout = WATCHDOG_NOWAYOUT;module_param(wdt_time, int, 0);MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="__MODULE_STRING(WDT_DEFAULT_TIME) ")");#ifdef CONFIG_WATCHDOG_NOWAYOUTmodule_param(nowayout, int, 0);MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");#endifstatic unsigned long ks8695wdt_busy;/* ......................................................................... *//* * Disable the watchdog. */static void inline ks8695_wdt_stop(void){	unsigned long tmcon;	/* disable timer0 */	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);}/* * Enable and reset the watchdog. */static void inline ks8695_wdt_start(void){	unsigned long tmcon;	unsigned long tval = wdt_time * CLOCK_TICK_RATE;	/* disable timer0 */	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);	/* program timer0 */	__raw_writel(tval | T0TC_WATCHDOG, KS8695_TMR_VA + KS8695_T0TC);	/* re-enable timer0 */	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);	__raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);}/* * Reload the watchdog timer.  (ie, pat the watchdog) */static void inline ks8695_wdt_reload(void){	unsigned long tmcon;	/* disable, then re-enable timer0 */	tmcon = __raw_readl(KS8695_TMR_VA + KS8695_TMCON);	__raw_writel(tmcon & ~TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);	__raw_writel(tmcon | TMCON_T0EN, KS8695_TMR_VA + KS8695_TMCON);}/* * Change the watchdog time interval. */static int ks8695_wdt_settimeout(int new_time){	/*	 * All counting occurs at SLOW_CLOCK / 128 = 0.256 Hz	 *	 * Since WDV is a 16-bit counter, the maximum period is	 * 65536 / 0.256 = 256 seconds.	 */	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))		return -EINVAL;	/* Set new watchdog time. It will be used when ks8695_wdt_start() is called. */	wdt_time = new_time;	return 0;}/* ......................................................................... *//* * Watchdog device is opened, and watchdog starts running. */static int ks8695_wdt_open(struct inode *inode, struct file *file){	if (test_and_set_bit(0, &ks8695wdt_busy))		return -EBUSY;	ks8695_wdt_start();	return nonseekable_open(inode, file);}/* * Close the watchdog device. * If CONFIG_WATCHDOG_NOWAYOUT is NOT defined then the watchdog is also *  disabled. */static int ks8695_wdt_close(struct inode *inode, struct file *file){	if (!nowayout)		ks8695_wdt_stop();	/* Disable the watchdog when file is closed */	clear_bit(0, &ks8695wdt_busy);	return 0;}static struct watchdog_info ks8695_wdt_info = {	.identity	= "ks8695 watchdog",	.options	= WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,};/* * Handle commands from user-space. */static int ks8695_wdt_ioctl(struct inode *inode, struct file *file,		unsigned int cmd, unsigned long arg){	void __user *argp = (void __user *)arg;	int __user *p = argp;	int new_value;	switch(cmd) {		case WDIOC_KEEPALIVE:			ks8695_wdt_reload();	/* pat the watchdog */			return 0;		case WDIOC_GETSUPPORT:			return copy_to_user(argp, &ks8695_wdt_info, sizeof(ks8695_wdt_info)) ? -EFAULT : 0;		case WDIOC_SETTIMEOUT:			if (get_user(new_value, p))				return -EFAULT;			if (ks8695_wdt_settimeout(new_value))				return -EINVAL;			/* Enable new time value */			ks8695_wdt_start();			/* Return current value */			return put_user(wdt_time, p);		case WDIOC_GETTIMEOUT:			return put_user(wdt_time, p);		case WDIOC_GETSTATUS:		case WDIOC_GETBOOTSTATUS:			return put_user(0, p);		case WDIOC_SETOPTIONS:			if (get_user(new_value, p))				return -EFAULT;			if (new_value & WDIOS_DISABLECARD)				ks8695_wdt_stop();			if (new_value & WDIOS_ENABLECARD)				ks8695_wdt_start();			return 0;		default:			return -ENOTTY;	}}/* * Pat the watchdog whenever device is written to. */static ssize_t ks8695_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos){	ks8695_wdt_reload();		/* pat the watchdog */	return len;}/* ......................................................................... */static const struct file_operations ks8695wdt_fops = {	.owner		= THIS_MODULE,	.llseek		= no_llseek,	.ioctl		= ks8695_wdt_ioctl,	.open		= ks8695_wdt_open,	.release	= ks8695_wdt_close,	.write		= ks8695_wdt_write,};static struct miscdevice ks8695wdt_miscdev = {	.minor		= WATCHDOG_MINOR,	.name		= "watchdog",	.fops		= &ks8695wdt_fops,};static int __init ks8695wdt_probe(struct platform_device *pdev){	int res;	if (ks8695wdt_miscdev.parent)		return -EBUSY;	ks8695wdt_miscdev.parent = &pdev->dev;	res = misc_register(&ks8695wdt_miscdev);	if (res)		return res;	printk("KS8695 Watchdog Timer enabled (%d seconds%s)\n", wdt_time, nowayout ? ", nowayout" : "");	return 0;}static int __exit ks8695wdt_remove(struct platform_device *pdev){	int res;	res = misc_deregister(&ks8695wdt_miscdev);	if (!res)		ks8695wdt_miscdev.parent = NULL;	return res;}static void ks8695wdt_shutdown(struct platform_device *pdev){	ks8695_wdt_stop();}#ifdef CONFIG_PMstatic int ks8695wdt_suspend(struct platform_device *pdev, pm_message_t message){	ks8695_wdt_stop();	return 0;}static int ks8695wdt_resume(struct platform_device *pdev){	if (ks8695wdt_busy)		ks8695_wdt_start();	return 0;}#else#define ks8695wdt_suspend NULL#define ks8695wdt_resume	NULL#endifstatic struct platform_driver ks8695wdt_driver = {	.probe		= ks8695wdt_probe,	.remove		= __exit_p(ks8695wdt_remove),	.shutdown	= ks8695wdt_shutdown,	.suspend	= ks8695wdt_suspend,	.resume		= ks8695wdt_resume,	.driver		= {		.name	= "ks8695_wdt",		.owner	= THIS_MODULE,	},};static int __init ks8695_wdt_init(void){	/* Check that the heartbeat value is within range; if not reset to the default */	if (ks8695_wdt_settimeout(wdt_time)) {		ks8695_wdt_settimeout(WDT_DEFAULT_TIME);		pr_info("ks8695_wdt: wdt_time value must be 1 <= wdt_time <= %i, using %d\n", wdt_time, WDT_MAX_TIME);	}	return platform_driver_register(&ks8695wdt_driver);}static void __exit ks8695_wdt_exit(void){	platform_driver_unregister(&ks8695wdt_driver);}module_init(ks8695_wdt_init);module_exit(ks8695_wdt_exit);MODULE_AUTHOR("Andrew Victor");MODULE_DESCRIPTION("Watchdog driver for KS8695");MODULE_LICENSE("GPL");MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);