patch-2.4.1 linux/drivers/sbus/char/cpwatchdog.c

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diff -u --recursive --new-file v2.4.0/linux/drivers/sbus/char/cpwatchdog.c linux/drivers/sbus/char/cpwatchdog.c
@@ -0,0 +1,838 @@
+/* cpwatchdog.c - driver implementation for hardware watchdog
+ * timers found on Sun Microsystems CP1400 and CP1500 boards.
+ *
+ * This device supports both the generic Linux watchdog 
+ * interface and Solaris-compatible ioctls as best it is
+ * able.
+ *
+ * NOTE: 	CP1400 systems appear to have a defective intr_mask
+ * 			register on the PLD, preventing the disabling of
+ * 			timer interrupts.  We use a timer to periodically 
+ * 			reset 'stopped' watchdogs on affected platforms.
+ *
+ * TODO:	DevFS support (/dev/watchdogs/0 ... /dev/watchdogs/2)
+ *
+ * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/major.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <asm/irq.h>
+#include <asm/ebus.h>
+#include <asm/oplib.h>
+#include <asm/uaccess.h>
+
+#include <asm/watchdog.h>
+
+#define WD_OBPNAME	"watchdog"
+#define WD_BADMODEL "SUNW,501-5336"
+#define WD_BTIMEOUT	(jiffies + (HZ * 1000))
+#define WD_BLIMIT	0xFFFF
+
+#define WD0_DEVNAME "watchdog0"
+#define WD1_DEVNAME "watchdog1"
+#define WD2_DEVNAME "watchdog2"
+
+#define WD0_MINOR	212
+#define WD1_MINOR	213	
+#define WD2_MINOR	214	
+
+
+/* Internal driver definitions
+ */
+#define WD0_ID			0		/* Watchdog0						*/
+#define WD1_ID			1		/* Watchdog1						*/
+#define WD2_ID			2		/* Watchdog2						*/
+#define WD_NUMDEVS		3		/* Device contains 3 timers			*/
+
+#define WD_INTR_OFF		0		/* Interrupt disable value			*/
+#define WD_INTR_ON		1		/* Interrupt enable value			*/
+
+#define WD_STAT_INIT	0x01	/* Watchdog timer is initialized	*/
+#define WD_STAT_BSTOP	0x02	/* Watchdog timer is brokenstopped	*/
+#define WD_STAT_SVCD	0x04	/* Watchdog interrupt occurred		*/
+
+/* Register value definitions
+ */
+#define WD0_INTR_MASK	0x01	/* Watchdog device interrupt masks	*/
+#define WD1_INTR_MASK	0x02
+#define WD2_INTR_MASK	0x04
+
+#define WD_S_RUNNING	0x01	/* Watchdog device status running	*/
+#define WD_S_EXPIRED	0x02	/* Watchdog device status expired	*/
+
+/* Sun uses Altera PLD EPF8820ATC144-4 
+ * providing three hardware watchdogs:
+ *
+ * 	1) RIC - sends an interrupt when triggered
+ * 	2) XIR - asserts XIR_B_RESET when triggered, resets CPU
+ * 	3) POR - asserts POR_B_RESET when triggered, resets CPU, backplane, board
+ *
+ *** Timer register block definition (struct wd_timer_regblk)
+ *
+ * dcntr and limit registers (halfword access):      
+ * -------------------
+ * | 15 | ...| 1 | 0 |
+ * -------------------
+ * |-  counter val  -|
+ * -------------------
+ * dcntr - 	Current 16-bit downcounter value.
+ * 			When downcounter reaches '0' watchdog expires.
+ * 			Reading this register resets downcounter with 'limit' value.
+ * limit - 	16-bit countdown value in 1/10th second increments.
+ * 			Writing this register begins countdown with input value.
+ * 			Reading from this register does not affect counter.
+ * NOTES:	After watchdog reset, dcntr and limit contain '1'
+ *
+ * status register (byte access):
+ * ---------------------------
+ * | 7 | ... | 2 |  1  |  0  |
+ * --------------+------------
+ * |-   UNUSED  -| EXP | RUN |
+ * ---------------------------
+ * status-	Bit 0 - Watchdog is running
+ * 			Bit 1 - Watchdog has expired
+ *
+ *** PLD register block definition (struct wd_pld_regblk)
+ *
+ * intr_mask register (byte access):
+ * ---------------------------------
+ * | 7 | ... | 3 |  2  |  1  |  0  |
+ * +-------------+------------------
+ * |-   UNUSED  -| WD3 | WD2 | WD1 |
+ * ---------------------------------
+ * WD3 -  1 == Interrupt disabled for watchdog 3
+ * WD2 -  1 == Interrupt disabled for watchdog 2
+ * WD1 -  1 == Interrupt disabled for watchdog 1
+ *
+ * pld_status register (byte access):
+ * UNKNOWN, MAGICAL MYSTERY REGISTER
+ *
+ */
+struct wd_timer_regblk {
+	volatile __u16	dcntr;		/* down counter		- hw	*/
+	volatile __u16	dcntr_pad;
+	volatile __u16	limit;		/* limit register	- hw	*/
+	volatile __u16	limit_pad;
+	volatile __u8	status;		/* status register	- b		*/
+	volatile __u8	status_pad;
+	volatile __u16	status_pad2;
+	volatile __u32	pad32;		/* yet more padding			*/
+};
+
+struct wd_pld_regblk {
+	volatile __u8	intr_mask;	/* interrupt mask	- b		*/
+	volatile __u8	intr_mask_pad;
+	volatile __u16	intr_mask_pad2;
+	volatile __u8	status;		/* device status	- b		*/
+	volatile __u8	status_pad;
+	volatile __u16	status_pad2;
+};
+
+struct wd_regblk {
+	volatile struct wd_timer_regblk		wd0_regs;
+	volatile struct wd_timer_regblk		wd1_regs;
+	volatile struct wd_timer_regblk		wd2_regs;
+	volatile struct wd_pld_regblk		pld_regs;
+};
+
+/* Individual timer structure 
+ */
+struct wd_timer {
+	__u16			timeout;
+	__u8			intr_mask;
+	unsigned char	runstatus;
+	volatile struct wd_timer_regblk* regs;
+};
+
+/* Device structure
+ */
+struct wd_device {
+	int				irq;
+	spinlock_t		lock;
+	unsigned char	isbaddoggie;	/* defective PLD */
+	unsigned char	opt_enable;
+	unsigned char	opt_reboot;
+	unsigned short	opt_timeout;
+	unsigned char	initialized;
+	struct wd_timer	watchdog[WD_NUMDEVS];
+	volatile struct	wd_regblk* regs;
+};
+
+static struct wd_device wd_dev = { 
+		0, SPIN_LOCK_UNLOCKED, 0, 0, 0, 0,
+};
+
+struct timer_list wd_timer;
+
+static int wd0_timeout = 0;
+static int wd1_timeout = 0;
+static int wd2_timeout = 0;
+
+#ifdef MODULE
+EXPORT_NO_SYMBOLS;
+
+MODULE_PARM		(wd0_timeout, "i");
+MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs");
+MODULE_PARM 	(wd1_timeout, "i");
+MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs");
+MODULE_PARM 	(wd2_timeout, "i");
+MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs");
+
+MODULE_AUTHOR
+	("Eric Brower <ebrower@usa.net>");
+MODULE_DESCRIPTION
+	("Hardware watchdog driver for Sun Microsystems CP1400/1500");
+MODULE_SUPPORTED_DEVICE
+	("watchdog");
+#endif /* ifdef MODULE */
+
+/* Forward declarations of internal methods
+ */
+void wd_dumpregs(void);
+void wd_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+void wd_toggleintr(struct wd_timer* pTimer, int enable);
+void wd_pingtimer(struct wd_timer* pTimer);
+void wd_starttimer(struct wd_timer* pTimer);
+void wd_resetbrokentimer(struct wd_timer* pTimer);
+void wd_stoptimer(struct wd_timer* pTimer);
+void wd_brokentimer(unsigned long data);
+int  wd_getstatus(struct wd_timer* pTimer);
+
+/* PLD expects words to be written in LSB format,
+ * so we must flip all words prior to writing them to regs
+ */
+inline unsigned short flip_word(unsigned short word)
+{
+	return ((word & 0xff) << 8) | ((word >> 8) & 0xff);
+}
+
+#define wd_writew(val, addr) 	(writew(flip_word(val), addr))
+#define wd_readw(addr) 			(flip_word(readw(addr)))
+#define wd_writeb(val, addr) 	(writeb(val, addr))
+#define wd_readb(addr) 			(readb(addr))
+
+
+/* CP1400s seem to have broken PLD implementations--
+ * the interrupt_mask register cannot be written, so
+ * no timer interrupts can be masked within the PLD.
+ */
+static inline int wd_isbroken(void)
+{
+	/* we could test this by read/write/read/restore
+	 * on the interrupt mask register only if OBP
+	 * 'watchdog-enable?' == FALSE, but it seems 
+	 * ubiquitous on CP1400s
+	 */
+	char val[32];
+	prom_getproperty(prom_root_node, "model", val, sizeof(val));
+	return((!strcmp(val, WD_BADMODEL)) ? 1 : 0);
+}
+		
+/* Retrieve watchdog-enable? option from OBP
+ * Returns 0 if false, 1 if true
+ */
+static inline int wd_opt_enable(void)
+{
+	int opt_node;
+
+	opt_node = prom_getchild(prom_root_node);
+	opt_node = prom_searchsiblings(opt_node, "options");
+	return((-1 == prom_getint(opt_node, "watchdog-enable?")) ? 0 : 1);
+}
+
+/* Retrieve watchdog-reboot? option from OBP
+ * Returns 0 if false, 1 if true
+ */
+static inline int wd_opt_reboot(void)
+{
+	int opt_node;
+
+	opt_node = prom_getchild(prom_root_node);
+	opt_node = prom_searchsiblings(opt_node, "options");
+	return((-1 == prom_getint(opt_node, "watchdog-reboot?")) ? 0 : 1);
+}
+
+/* Retrieve watchdog-timeout option from OBP
+ * Returns OBP value, or 0 if not located
+ */
+static inline int wd_opt_timeout(void)
+{
+	int opt_node;
+	char value[32];
+	char *p = value;
+
+	opt_node = prom_getchild(prom_root_node);
+	opt_node = prom_searchsiblings(opt_node, "options");
+	opt_node = prom_getproperty(opt_node, 
+								"watchdog-timeout", 
+								value, 
+								sizeof(value));
+	if(-1 != opt_node) {
+		/* atoi implementation */
+		for(opt_node = 0; /* nop */; p++) {
+			if(*p >= '0' && *p <= '9') {
+				opt_node = (10*opt_node)+(*p-'0');
+			}
+			else {
+				break;
+			}
+		}
+	}
+	return((-1 == opt_node) ? (0) : (opt_node)); 
+}
+
+static int wd_open(struct inode *inode, struct file *f)
+{
+	switch(MINOR(inode->i_rdev))
+	{
+		case WD0_MINOR:
+			f->private_data = &wd_dev.watchdog[WD0_ID];
+			break;
+		case WD1_MINOR:
+			f->private_data = &wd_dev.watchdog[WD1_ID];
+			break;
+		case WD2_MINOR:
+			f->private_data = &wd_dev.watchdog[WD2_ID];
+			break;
+		default:
+			return(-ENODEV);
+	}
+
+	/* Register IRQ on first open of device */
+	if(0 == wd_dev.initialized)
+	{	
+		if (request_irq(wd_dev.irq, 
+						&wd_interrupt, 
+						SA_SHIRQ,
+						WD_OBPNAME,
+						(void *)wd_dev.regs)) {
+			printk("%s: Cannot register IRQ %s\n", 
+				WD_OBPNAME, __irq_itoa(wd_dev.irq));
+			return(-EBUSY);
+		}
+		wd_dev.initialized = 1;
+	}
+
+	MOD_INC_USE_COUNT;
+	return(0);
+}
+
+static int wd_release(struct inode *inode, struct file *file)
+{
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
+
+static int wd_ioctl(struct inode *inode, struct file *file, 
+		     unsigned int cmd, unsigned long arg)
+{
+	int 	setopt 				= 0;
+	struct 	wd_timer* pTimer 	= (struct wd_timer*)file->private_data;
+	struct 	watchdog_info info 	= {
+		0,
+		0,
+		"Altera EPF8820ATC144-4"
+	};
+
+	if(NULL == pTimer) {
+		return(-EINVAL);
+	}
+
+	switch(cmd)
+	{
+		/* Generic Linux IOCTLs */
+		case WDIOC_GETSUPPORT:
+			if(copy_to_user((struct watchdog_info *)arg, 
+							(struct watchdog_info *)&info, 
+							sizeof(struct watchdog_info *))) {
+				return(-EFAULT);
+			}
+			break;
+		case WDIOC_KEEPALIVE:
+			wd_pingtimer(pTimer);
+			break;
+		case WDIOC_SETOPTIONS:
+			if(copy_from_user(&setopt, (void*) arg, sizeof(unsigned int))) {
+				return -EFAULT;
+			}
+			if(setopt & WDIOS_DISABLECARD) {
+				if(wd_dev.opt_enable) {
+					printk(
+						"%s: cannot disable watchdog in ENABLED mode\n",
+						WD_OBPNAME);
+					return(-EINVAL);
+				}
+				wd_stoptimer(pTimer);
+			}
+			else if(setopt & WDIOS_ENABLECARD) {
+				wd_starttimer(pTimer);
+			}
+			else {
+				return(-EINVAL);
+			}	
+			break;
+		/* Solaris-compatible IOCTLs */
+		case WIOCGSTAT:
+			setopt = wd_getstatus(pTimer);
+			if(copy_to_user((void*)arg, &setopt, sizeof(unsigned int))) {
+				return(-EFAULT);
+			}
+			break;
+		case WIOCSTART:
+			wd_starttimer(pTimer);
+			break;
+		case WIOCSTOP:
+			if(wd_dev.opt_enable) {
+				printk("%s: cannot disable watchdog in ENABLED mode\n",
+					WD_OBPNAME);
+				return(-EINVAL);
+			}
+			wd_stoptimer(pTimer);
+			break;
+		default:
+			return(-EINVAL);
+	}
+	return(0);
+}
+
+static ssize_t wd_write(	struct file 	*file, 
+							const char		*buf, 
+							size_t 			count, 
+							loff_t 			*ppos)
+{
+	struct wd_timer* pTimer = (struct wd_timer*)file->private_data;
+
+	if(NULL == pTimer) {
+		return(-EINVAL);
+	}
+
+	wd_pingtimer(pTimer);
+	return(count);
+}
+
+static ssize_t wd_read(struct file * file, char * buffer,
+		        size_t count, loff_t *ppos)
+{
+#ifdef WD_DEBUG
+	wd_dumpregs();
+	return(0);
+#else
+	return(-EINVAL);
+#endif /* ifdef WD_DEBUG */
+}
+
+void wd_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	/* Only WD0 will interrupt-- others are NMI and we won't
+	 * see them here....
+	 */
+	spin_lock_irq(&wd_dev.lock);
+	if((unsigned long)wd_dev.regs == (unsigned long)dev_id)
+	{
+		wd_stoptimer(&wd_dev.watchdog[WD0_ID]);
+		wd_dev.watchdog[WD0_ID].runstatus |=  WD_STAT_SVCD;
+	}
+	spin_unlock_irq(&wd_dev.lock);
+	return;
+}
+
+static struct file_operations wd_fops = {
+	owner:		THIS_MODULE,
+	ioctl:		wd_ioctl,
+	open:		wd_open,
+	write:		wd_write,
+	read:		wd_read,
+	release:	wd_release,
+};
+
+static struct miscdevice wd0_miscdev = { WD0_MINOR, WD0_DEVNAME, &wd_fops };
+static struct miscdevice wd1_miscdev = { WD1_MINOR, WD1_DEVNAME, &wd_fops };
+static struct miscdevice wd2_miscdev = { WD2_MINOR, WD2_DEVNAME, &wd_fops };
+
+void wd_dumpregs(void)
+{
+	/* Reading from downcounters initiates watchdog countdown--
+	 * Example is included below for illustration purposes.
+	 */
+	int i;
+	printk("%s: dumping register values\n", WD_OBPNAME);
+	for(i = WD0_ID; i < WD_NUMDEVS; ++i) {
+			/* printk("\t%s%i: dcntr  at 0x%lx: 0x%x\n", 
+			 * 	WD_OBPNAME,
+		 	 *	i,
+			 *	(unsigned long)(&wd_dev.watchdog[i].regs->dcntr), 
+			 *	readw(&wd_dev.watchdog[i].regs->dcntr));
+			 */
+			printk("\t%s%i: limit  at 0x%lx: 0x%x\n", 
+				WD_OBPNAME,
+				i,
+				(unsigned long)(&wd_dev.watchdog[i].regs->limit), 
+				readw(&wd_dev.watchdog[i].regs->limit));
+			printk("\t%s%i: status at 0x%lx: 0x%x\n", 
+				WD_OBPNAME,
+				i,
+				(unsigned long)(&wd_dev.watchdog[i].regs->status), 
+				readb(&wd_dev.watchdog[i].regs->status));
+			printk("\t%s%i: driver status: 0x%x\n",
+				WD_OBPNAME,
+				i,
+				wd_getstatus(&wd_dev.watchdog[i]));
+	}
+	printk("\tintr_mask  at 0x%lx: 0x%x\n", 
+		(unsigned long)(&wd_dev.regs->pld_regs.intr_mask), 
+		readb(&wd_dev.regs->pld_regs.intr_mask));
+	printk("\tpld_status at 0x%lx: 0x%x\n", 
+		(unsigned long)(&wd_dev.regs->pld_regs.status), 
+		readb(&wd_dev.regs->pld_regs.status));
+}
+
+/* Enable or disable watchdog interrupts
+ * Because of the CP1400 defect this should only be
+ * called during initialzation or by wd_[start|stop]timer()
+ *
+ * pTimer 	- pointer to timer device, or NULL to indicate all timers 
+ * enable	- non-zero to enable interrupts, zero to disable
+ */
+void wd_toggleintr(struct wd_timer* pTimer, int enable)
+{
+	unsigned char curregs = wd_readb(&wd_dev.regs->pld_regs.intr_mask);
+	unsigned char setregs = 
+		(NULL == pTimer) ? 
+			(WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) : 
+			(pTimer->intr_mask);
+
+	(WD_INTR_ON == enable) ?
+		(curregs &= ~setregs):
+		(curregs |=  setregs);
+
+	wd_writeb(curregs, &wd_dev.regs->pld_regs.intr_mask);
+	return;
+}
+
+/* Reset countdown timer with 'limit' value and continue countdown.
+ * This will not start a stopped timer.
+ *
+ * pTimer	- pointer to timer device
+ */
+void wd_pingtimer(struct wd_timer* pTimer)
+{
+	if(wd_readb(&pTimer->regs->status) & WD_S_RUNNING) {
+		wd_readb(&pTimer->regs->dcntr);
+	}
+}
+
+/* Stop a running watchdog timer-- the timer actually keeps
+ * running, but the interrupt is masked so that no action is
+ * taken upon expiration.
+ *
+ * pTimer	- pointer to timer device
+ */
+void wd_stoptimer(struct wd_timer* pTimer)
+{
+	if(wd_readb(&pTimer->regs->status) & WD_S_RUNNING) {
+		wd_toggleintr(pTimer, WD_INTR_OFF);
+
+		if(wd_dev.isbaddoggie) {
+			pTimer->runstatus |= WD_STAT_BSTOP;
+			wd_brokentimer((unsigned long)&wd_dev);
+		}
+	}
+}
+
+/* Start a watchdog timer with the specified limit value
+ * If the watchdog is running, it will be restarted with
+ * the provided limit value.
+ *
+ * This function will enable interrupts on the specified
+ * watchdog.
+ *
+ * pTimer	- pointer to timer device
+ * limit	- limit (countdown) value in 1/10th seconds
+ */
+void wd_starttimer(struct wd_timer* pTimer)
+{
+	if(wd_dev.isbaddoggie) {
+		pTimer->runstatus &= ~WD_STAT_BSTOP;
+	}
+	pTimer->runstatus &= ~WD_STAT_SVCD;
+
+	wd_writew(pTimer->timeout, &pTimer->regs->limit);
+	wd_toggleintr(pTimer, WD_INTR_ON);
+}
+
+/* Restarts timer with maximum limit value and
+ * does not unset 'brokenstop' value.
+ */
+void wd_resetbrokentimer(struct wd_timer* pTimer)
+{
+	wd_toggleintr(pTimer, WD_INTR_ON);
+	wd_writew(WD_BLIMIT, &pTimer->regs->limit);
+}
+
+/* Timer device initialization helper.
+ * Returns 0 on success, other on failure
+ */
+int wd_inittimer(int whichdog)
+{
+	struct miscdevice 				*whichmisc;
+	volatile struct wd_timer_regblk	*whichregs;
+	char 							whichident[8];
+	int								whichmask;
+	__u16							whichlimit;
+
+	switch(whichdog)
+	{
+		case WD0_ID:
+			whichmisc = &wd0_miscdev;
+			strcpy(whichident, "RIC");
+			whichregs = &wd_dev.regs->wd0_regs;
+			whichmask = WD0_INTR_MASK;
+			whichlimit= (0 == wd0_timeout) 	? 
+						(wd_dev.opt_timeout): 
+						(wd0_timeout);
+			break;
+		case WD1_ID:
+			whichmisc = &wd1_miscdev;
+			strcpy(whichident, "XIR");
+			whichregs = &wd_dev.regs->wd1_regs;
+			whichmask = WD1_INTR_MASK;
+			whichlimit= (0 == wd1_timeout) 	? 
+						(wd_dev.opt_timeout): 
+						(wd1_timeout);
+			break;
+		case WD2_ID:
+			whichmisc = &wd2_miscdev;
+			strcpy(whichident, "POR");
+			whichregs = &wd_dev.regs->wd2_regs;
+			whichmask = WD2_INTR_MASK;
+			whichlimit= (0 == wd2_timeout) 	? 
+						(wd_dev.opt_timeout): 
+						(wd2_timeout);
+			break;
+		default:
+			printk("%s: %s: invalid watchdog id: %i\n",
+				WD_OBPNAME, __FUNCTION__, whichdog);
+			return(1);
+	}
+	if(0 != misc_register(whichmisc))
+	{
+		return(1);
+	}
+	wd_dev.watchdog[whichdog].regs			= whichregs;
+	wd_dev.watchdog[whichdog].timeout 		= whichlimit;
+	wd_dev.watchdog[whichdog].intr_mask		= whichmask;
+	wd_dev.watchdog[whichdog].runstatus 	&= ~WD_STAT_BSTOP;
+	wd_dev.watchdog[whichdog].runstatus 	|= WD_STAT_INIT;
+
+	printk("%s%i: %s hardware watchdog [%01i.%i sec] %s\n", 
+		WD_OBPNAME, 
+		whichdog, 
+		whichident, 
+		wd_dev.watchdog[whichdog].timeout / 10,
+		wd_dev.watchdog[whichdog].timeout % 10,
+		(0 != wd_dev.opt_enable) ? "in ENABLED mode" : "");
+	return(0);
+}
+
+/* Timer method called to reset stopped watchdogs--
+ * because of the PLD bug on CP1400, we cannot mask
+ * interrupts within the PLD so me must continually
+ * reset the timers ad infinitum.
+ */
+void wd_brokentimer(unsigned long data)
+{
+	struct wd_device* pDev = (struct wd_device*)data;
+	int id, tripped = 0;
+
+	/* kill a running timer instance, in case we
+	 * were called directly instead of by kernel timer
+	 */
+	if(timer_pending(&wd_timer)) {
+		del_timer(&wd_timer);
+	}
+
+	for(id = WD0_ID; id < WD_NUMDEVS; ++id) {
+		if(pDev->watchdog[id].runstatus & WD_STAT_BSTOP) {
+			++tripped;
+			wd_resetbrokentimer(&pDev->watchdog[id]);
+		}
+	}
+
+	if(tripped) {
+		/* there is at least one timer brokenstopped-- reschedule */
+		wd_timer.expires = WD_BTIMEOUT;
+		add_timer(&wd_timer);
+	}
+}
+
+int wd_getstatus(struct wd_timer* pTimer)
+{
+	unsigned char stat = wd_readb(&pTimer->regs->status);
+	unsigned char intr = wd_readb(&wd_dev.regs->pld_regs.intr_mask);
+	unsigned char ret  = WD_STOPPED;
+
+	/* determine STOPPED */
+	if(0 == stat ) { 
+		return(ret);
+	}
+	/* determine EXPIRED vs FREERUN vs RUNNING */
+	else if(WD_S_EXPIRED & stat) {
+		ret = WD_EXPIRED;
+	}
+	else if(WD_S_RUNNING & stat) {
+		if(intr & pTimer->intr_mask) {
+			ret = WD_FREERUN;
+		}
+		else {
+			/* Fudge WD_EXPIRED status for defective CP1400--
+			 * IF timer is running 
+			 * 	AND brokenstop is set 
+			 * 	AND an interrupt has been serviced
+			 * we are WD_EXPIRED.
+			 *
+			 * IF timer is running 
+			 * 	AND brokenstop is set 
+			 * 	AND no interrupt has been serviced
+			 * we are WD_FREERUN.
+			 */
+			if(wd_dev.isbaddoggie && (pTimer->runstatus & WD_STAT_BSTOP)) {
+				if(pTimer->runstatus & WD_STAT_SVCD) {
+					ret = WD_EXPIRED;
+				}
+				else {
+					/* we could as well pretend we are expired */
+					ret = WD_FREERUN;
+				}
+			}
+			else {
+				ret = WD_RUNNING;
+			}
+		}
+	}
+
+	/* determine SERVICED */
+	if(pTimer->runstatus & WD_STAT_SVCD) {
+		ret |= WD_SERVICED;
+	}
+
+	return(ret);
+}
+
+static int __init wd_init(void)
+{
+	int 	id;
+	struct 	linux_ebus *ebus = NULL;
+	struct 	linux_ebus_device *edev = NULL;
+
+	for_each_ebus(ebus) {
+		for_each_ebusdev(edev, ebus) {
+			if (!strcmp(edev->prom_name, WD_OBPNAME))
+				goto ebus_done;
+		}
+	}
+
+ebus_done:
+	if(!edev) {
+		printk("%s: unable to locate device\n", WD_OBPNAME);
+		return -ENODEV;
+	}
+
+	wd_dev.regs = 
+		ioremap(edev->resource[0].start, sizeof(struct wd_regblk));
+
+	if(NULL == wd_dev.regs) {
+		printk("%s: unable to map registers\n", WD_OBPNAME);
+		return(-ENODEV);
+	}
+
+	/* initialize device structure from OBP parameters */
+	wd_dev.irq 			= edev->irqs[0];
+	wd_dev.opt_enable	= wd_opt_enable();
+	wd_dev.opt_reboot	= wd_opt_reboot();
+	wd_dev.opt_timeout	= wd_opt_timeout();
+	wd_dev.isbaddoggie	= wd_isbroken();
+
+	/* disable all interrupts unless watchdog-enabled? == true */
+	if(! wd_dev.opt_enable) {
+		wd_toggleintr(NULL, WD_INTR_OFF);
+	}
+
+	/* register miscellaneous devices */
+	for(id = WD0_ID; id < WD_NUMDEVS; ++id) {
+		if(0 != wd_inittimer(id)) {
+			printk("%s%i: unable to initialize\n", WD_OBPNAME, id);
+		}
+	}
+
+	/* warn about possible defective PLD */
+	if(wd_dev.isbaddoggie) {
+		init_timer(&wd_timer);
+		wd_timer.function 	= wd_brokentimer;
+		wd_timer.data		= (unsigned long)&wd_dev;
+		wd_timer.expires	= WD_BTIMEOUT;
+
+		printk("%s: PLD defect workaround enabled for model %s\n",
+			WD_OBPNAME, WD_BADMODEL);
+	}
+	return(0);
+}
+
+static void __exit wd_cleanup(void)
+{
+	int id;
+
+	/* if 'watchdog-enable?' == TRUE, timers are not stopped 
+	 * when module is unloaded.  All brokenstopped timers will
+	 * also now eventually trip. 
+	 */
+	for(id = WD0_ID; id < WD_NUMDEVS; ++id) {
+		if(WD_S_RUNNING == wd_readb(&wd_dev.watchdog[id].regs->status)) {
+			if(wd_dev.opt_enable) {
+				printk(KERN_WARNING "%s%i: timer not stopped at release\n",
+					WD_OBPNAME, id);
+			}
+			else {
+				wd_stoptimer(&wd_dev.watchdog[id]);
+				if(wd_dev.watchdog[id].runstatus & WD_STAT_BSTOP) {
+					wd_resetbrokentimer(&wd_dev.watchdog[id]);
+					printk(KERN_WARNING 
+							"%s%i: defect workaround disabled at release, "\
+							"timer expires in ~%01i sec\n",
+							WD_OBPNAME, id, 
+							wd_readw(&wd_dev.watchdog[id].regs->limit) / 10);
+				}
+			}
+		}
+	}
+
+	if(wd_dev.isbaddoggie && timer_pending(&wd_timer)) {
+		del_timer(&wd_timer);
+	}
+	if(0 != (wd_dev.watchdog[WD0_ID].runstatus & WD_STAT_INIT)) {
+		misc_deregister(&wd0_miscdev);
+	}
+	if(0 != (wd_dev.watchdog[WD1_ID].runstatus & WD_STAT_INIT)) {
+		misc_deregister(&wd1_miscdev);
+	}
+	if(0 != (wd_dev.watchdog[WD2_ID].runstatus & WD_STAT_INIT)) {
+		misc_deregister(&wd2_miscdev);
+	}
+	if(0 != wd_dev.initialized) {
+		free_irq(wd_dev.irq, (void *)wd_dev.regs);
+	}
+	iounmap(wd_dev.regs);
+}
+
+module_init(wd_init);
+module_exit(wd_cleanup);
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)