cpwatchdog: Cleanup and convert to pure OF driver.
David S. Miller [Sat, 30 Aug 2008 00:05:51 +0000 (17:05 -0700)]
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/sbus/char/cpwatchdog.c

index 23abfdf..c88df62 100644 (file)
@@ -11,6 +11,7 @@
  *                     reset 'stopped' watchdogs on affected platforms.
  *
  * Copyright (c) 2000 Eric Brower (ebrower@usa.net)
+ * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
  */
 
 #include <linux/kernel.h>
 #include <linux/timer.h>
 #include <linux/smp_lock.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
 #include <asm/irq.h>
-#include <asm/ebus.h>
-#include <asm/oplib.h>
 #include <asm/uaccess.h>
 
 #include <asm/watchdog.h>
 
+#define DRIVER_NAME    "cpwd"
+#define PFX            DRIVER_NAME ": "
+
 #define WD_OBPNAME     "watchdog"
-#define WD_BADMODEL "SUNW,501-5336"
+#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
+#define WD1_ID                 1
+#define WD2_ID                 2
+#define WD_NUMDEVS             3
 
-/* 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_INTR_OFF            0
+#define WD_INTR_ON             1
 
 #define WD_STAT_INIT   0x01    /* Watchdog timer is initialized        */
 #define WD_STAT_BSTOP  0x02    /* Watchdog timer is brokenstopped      */
 #define WD_S_RUNNING   0x01    /* Watchdog device status running       */
 #define WD_S_EXPIRED   0x02    /* Watchdog device status expired       */
 
+struct cpwd {
+       void __iomem    *regs;
+       spinlock_t      lock;
+
+       unsigned int    irq;
+
+       unsigned long   timeout;
+       bool            enabled;
+       bool            reboot;
+       bool            broken;
+       bool            initialized;
+
+       struct {
+               struct miscdevice       misc;
+               void __iomem            *regs;
+               u8                      intr_mask;
+               u8                      runstatus;
+               u16                     timeout;
+       } devs[WD_NUMDEVS];
+};
+
+static struct cpwd *cpwd_device;
+
 /* Sun uses Altera PLD EPF8820ATC144-4 
  * providing three hardware watchdogs:
  *
 #define PLD_IMASK      (PLD_OFF + 0x00)
 #define PLD_STATUS     (PLD_OFF + 0x04)
 
-/* Individual timer structure 
- */
-struct wd_timer {
-       __u16                   timeout;
-       __u8                    intr_mask;
-       unsigned char           runstatus;
-       void __iomem            *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];
-       void __iomem    *regs;
-};
-
-static struct wd_device wd_dev = { 
-               0, __SPIN_LOCK_UNLOCKED(wd_dev.lock), 0, 0, 0, 0,
-};
-
-static struct timer_list wd_timer;
+static struct timer_list cpwd_timer;
 
 static int wd0_timeout = 0;
 static int wd1_timeout = 0;
 static int wd2_timeout = 0;
 
-#ifdef MODULE
 module_param   (wd0_timeout, int, 0);
 MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs");
 module_param   (wd1_timeout, int, 0);
@@ -171,234 +165,313 @@ MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs");
 module_param   (wd2_timeout, int, 0);
 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_AUTHOR("Eric Brower <ebrower@usa.net>");
+MODULE_DESCRIPTION("Hardware watchdog driver for Sun Microsystems CP1400/1500");
 MODULE_LICENSE("GPL");
-MODULE_SUPPORTED_DEVICE
-       ("watchdog");
-#endif /* ifdef MODULE */
+MODULE_SUPPORTED_DEVICE("watchdog");
+
+static void cpwd_writew(u16 val, void __iomem *addr)
+{
+       writew(cpu_to_le16(val), addr);
+}
+static u16 cpwd_readw(void __iomem *addr)
+{
+       u16 val = readw(addr);
+
+       return le16_to_cpu(val);
+}
+
+static void cpwd_writeb(u8 val, void __iomem *addr)
+{
+       writeb(val, addr);
+}
+
+static u8 cpwd_readb(void __iomem *addr)
+{
+       return readb(addr);
+}
 
-/* Forward declarations of internal methods
+/* Enable or disable watchdog interrupts
+ * Because of the CP1400 defect this should only be
+ * called during initialzation or by wd_[start|stop]timer()
+ *
+ * index       - sub-device index, or -1 for 'all'
+ * enable      - non-zero to enable interrupts, zero to disable
  */
-#ifdef WD_DEBUG
-static void wd_dumpregs(void);
-#endif
-static irqreturn_t wd_interrupt(int irq, void *dev_id);
-static void wd_toggleintr(struct wd_timer* pTimer, int enable);
-static void wd_pingtimer(struct wd_timer* pTimer);
-static void wd_starttimer(struct wd_timer* pTimer);
-static void wd_resetbrokentimer(struct wd_timer* pTimer);
-static void wd_stoptimer(struct wd_timer* pTimer);
-static void wd_brokentimer(unsigned long data);
-static 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
+static void cpwd_toggleintr(struct cpwd *p, int index, int enable)
+{
+       unsigned char curregs = cpwd_readb(p->regs + PLD_IMASK);
+       unsigned char setregs = 
+               (index == -1) ? 
+               (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) : 
+               (p->devs[index].intr_mask);
+
+       if (enable == WD_INTR_ON)
+               curregs &= ~setregs;
+       else
+               curregs |= setregs;
+
+       cpwd_writeb(curregs, p->regs + PLD_IMASK);
+}
+
+/* Restarts timer with maximum limit value and
+ * does not unset 'brokenstop' value.
  */
-static inline unsigned short flip_word(unsigned short word)
+static void cpwd_resetbrokentimer(struct cpwd *p, int index)
 {
-       return ((word & 0xff) << 8) | ((word >> 8) & 0xff);
+       cpwd_toggleintr(p, index, WD_INTR_ON);
+       cpwd_writew(WD_BLIMIT, p->devs[index].regs + WD_LIMIT);
 }
 
-#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))
+/* 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.
+ */
+static void cpwd_brokentimer(unsigned long data)
+{
+       struct cpwd *p = (struct cpwd *) data;
+       int id, tripped = 0;
+
+       /* kill a running timer instance, in case we
+        * were called directly instead of by kernel timer
+        */
+       if (timer_pending(&cpwd_timer))
+               del_timer(&cpwd_timer);
 
+       for (id = 0; id < WD_NUMDEVS; id++) {
+               if (p->devs[id].runstatus & WD_STAT_BSTOP) {
+                       ++tripped;
+                       cpwd_resetbrokentimer(p, id);
+               }
+       }
 
-/* CP1400s seem to have broken PLD implementations--
- * the interrupt_mask register cannot be written, so
- * no timer interrupts can be masked within the PLD.
+       if (tripped) {
+               /* there is at least one timer brokenstopped-- reschedule */
+               cpwd_timer.expires = WD_BTIMEOUT;
+               add_timer(&cpwd_timer);
+       }
+}
+
+/* Reset countdown timer with 'limit' value and continue countdown.
+ * This will not start a stopped timer.
  */
-static inline int wd_isbroken(void)
+static void cpwd_pingtimer(struct cpwd *p, int index)
 {
-       /* 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);
+       if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING)
+               cpwd_readw(p->devs[index].regs + WD_DCNTR);
 }
-               
-/* Retrieve watchdog-enable? option from OBP
- * Returns 0 if false, 1 if true
+
+/* Stop a running watchdog timer-- the timer actually keeps
+ * running, but the interrupt is masked so that no action is
+ * taken upon expiration.
  */
-static inline int wd_opt_enable(void)
+static void cpwd_stoptimer(struct cpwd *p, int index)
 {
-       int opt_node;
+       if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING) {
+               cpwd_toggleintr(p, index, WD_INTR_OFF);
 
-       opt_node = prom_getchild(prom_root_node);
-       opt_node = prom_searchsiblings(opt_node, "options");
-       return((-1 == prom_getint(opt_node, "watchdog-enable?")) ? 0 : 1);
+               if (p->broken) {
+                       p->devs[index].runstatus |= WD_STAT_BSTOP;
+                       cpwd_brokentimer((unsigned long) p);
+               }
+       }
 }
 
-/* Retrieve watchdog-reboot? option from OBP
- * Returns 0 if false, 1 if true
+/* 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.
  */
-static inline int wd_opt_reboot(void)
+static void cpwd_starttimer(struct cpwd *p, int index)
 {
-       int opt_node;
+       if (p->broken)
+               p->devs[index].runstatus &= ~WD_STAT_BSTOP;
+
+       p->devs[index].runstatus &= ~WD_STAT_SVCD;
 
-       opt_node = prom_getchild(prom_root_node);
-       opt_node = prom_searchsiblings(opt_node, "options");
-       return((-1 == prom_getint(opt_node, "watchdog-reboot?")) ? 0 : 1);
+       cpwd_writew(p->devs[index].timeout, p->devs[index].regs + WD_LIMIT);
+       cpwd_toggleintr(p, index, WD_INTR_ON);
 }
 
-/* Retrieve watchdog-timeout option from OBP
- * Returns OBP value, or 0 if not located
- */
-static inline int wd_opt_timeout(void)
+static int cpwd_getstatus(struct cpwd *p, int index)
 {
-       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;
+       unsigned char stat = cpwd_readb(p->devs[index].regs + WD_STATUS);
+       unsigned char intr = cpwd_readb(p->devs[index].regs + PLD_IMASK);
+       unsigned char ret  = WD_STOPPED;
+
+       /* determine STOPPED */
+       if (!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 & p->devs[index].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 (p->broken &&
+                           (p->devs[index].runstatus & WD_STAT_BSTOP)) {
+                               if (p->devs[index].runstatus & WD_STAT_SVCD) {
+                                       ret = WD_EXPIRED;
+                               } else {
+                                       /* we could as well pretend we are expired */
+                                       ret = WD_FREERUN;
+                               }
+                       } else {
+                               ret = WD_RUNNING;
                        }
                }
        }
-       return((-1 == opt_node) ? (0) : (opt_node)); 
+
+       /* determine SERVICED */
+       if (p->devs[index].runstatus & WD_STAT_SVCD)
+               ret |= WD_SERVICED;
+
+       return(ret);
+}
+
+static irqreturn_t cpwd_interrupt(int irq, void *dev_id)
+{
+       struct cpwd *p = dev_id;
+
+       /* Only WD0 will interrupt-- others are NMI and we won't
+        * see them here....
+        */
+       spin_lock_irq(&p->lock);
+
+       cpwd_stoptimer(p, WD0_ID);
+       p->devs[WD0_ID].runstatus |=  WD_STAT_SVCD;
+
+       spin_unlock_irq(&p->lock);
+
+       return IRQ_HANDLED;
 }
 
-static int wd_open(struct inode *inode, struct file *f)
+static int cpwd_open(struct inode *inode, struct file *f)
 {
+       struct cpwd *p = cpwd_device;
+
        lock_kernel();
-       switch(iminor(inode))
-       {
+       switch(iminor(inode)) {
                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:
                        unlock_kernel();
-                       return(-ENODEV);
+                       return -ENODEV;
        }
 
        /* Register IRQ on first open of device */
-       if(0 == wd_dev.initialized)
-       {       
-               if (request_irq(wd_dev.irq, 
-                                               &wd_interrupt, 
-                                               IRQF_SHARED,
-                                               WD_OBPNAME,
-                                               (void *)wd_dev.regs)) {
-                       printk("%s: Cannot register IRQ %d\n", 
-                               WD_OBPNAME, wd_dev.irq);
+       if (!p->initialized) {
+               if (request_irq(p->irq, &cpwd_interrupt, 
+                               IRQF_SHARED, DRIVER_NAME, p)) {
+                       printk(KERN_ERR PFX "Cannot register IRQ %d\n", 
+                               p->irq);
                        unlock_kernel();
-                       return(-EBUSY);
+                       return -EBUSY;
                }
-               wd_dev.initialized = 1;
+               p->initialized = true;
        }
 
        unlock_kernel();
-       return(nonseekable_open(inode, f));
+
+       return nonseekable_open(inode, f);
 }
 
-static int wd_release(struct inode *inode, struct file *file)
+static int cpwd_release(struct inode *inode, struct file *file)
 {
        return 0;
 }
 
-static int wd_ioctl(struct inode *inode, struct file *file, 
-                    unsigned int cmd, unsigned long arg)
+static int cpwd_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;
-       void __user *argp = (void __user *)arg;
-       struct  watchdog_info info      = {
-               0,
-               0,
-               "Altera EPF8820ATC144-4"
+       static struct watchdog_info info = {
+               .options                = WDIOF_SETTIMEOUT,
+               .firmware_version       = 1,
+               .identity               = DRIVER_NAME,
        };
+       void __user *argp = (void __user *)arg;
+       int index = iminor(inode) - WD0_MINOR;
+       struct cpwd *p = cpwd_device;
+       int setopt = 0;
 
-       if(NULL == pTimer) {
-               return(-EINVAL);
-       }
+       switch (cmd) {
+       /* Generic Linux IOCTLs */
+       case WDIOC_GETSUPPORT:
+               if (copy_to_user(argp, &info, sizeof(struct watchdog_info)))
+                       return -EFAULT;
+               break;
 
-       switch(cmd)
-       {
-               /* Generic Linux IOCTLs */
-               case WDIOC_GETSUPPORT:
-                       if(copy_to_user(argp, &info, sizeof(struct watchdog_info))) {
-                               return(-EFAULT);
-                       }
-                       break;
-               case WDIOC_GETSTATUS:
-               case WDIOC_GETBOOTSTATUS:
-                       if (put_user(0, (int __user *)argp))
-                               return -EFAULT;
-                       break;
-               case WDIOC_KEEPALIVE:
-                       wd_pingtimer(pTimer);
-                       break;
-               case WDIOC_SETOPTIONS:
-                       if(copy_from_user(&setopt, argp, 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(argp, &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:
+       case WDIOC_GETSTATUS:
+       case WDIOC_GETBOOTSTATUS:
+               if (put_user(0, (int __user *)argp))
+                       return -EFAULT;
+               break;
+
+       case WDIOC_KEEPALIVE:
+               cpwd_pingtimer(p, index);
+               break;
+
+       case WDIOC_SETOPTIONS:
+               if (copy_from_user(&setopt, argp, sizeof(unsigned int)))
+                       return -EFAULT;
+
+               if (setopt & WDIOS_DISABLECARD) {
+                       if (p->enabled)
+                               return -EINVAL;
+                       cpwd_stoptimer(p, index);
+               } else if (setopt & WDIOS_ENABLECARD) {
+                       cpwd_starttimer(p, index);
+               } else {
+                       return -EINVAL;
+               }       
+               break;
+
+       /* Solaris-compatible IOCTLs */
+       case WIOCGSTAT:
+               setopt = cpwd_getstatus(p, index);
+               if (copy_to_user(argp, &setopt, sizeof(unsigned int)))
+                       return -EFAULT;
+               break;
+
+       case WIOCSTART:
+               cpwd_starttimer(p, index);
+               break;
+
+       case WIOCSTOP:
+               if (p->enabled)
                        return(-EINVAL);
+
+               cpwd_stoptimer(p, index);
+               break;
+
+       default:
+               return -EINVAL;
        }
-       return(0);
+
+       return 0;
 }
 
-static long wd_compat_ioctl(struct file *file, unsigned int cmd,
-               unsigned long arg)
+static long cpwd_compat_ioctl(struct file *file, unsigned int cmd,
+                             unsigned long arg)
 {
        int rval = -ENOIOCTLCMD;
 
@@ -408,9 +481,10 @@ static long wd_compat_ioctl(struct file *file, unsigned int cmd,
        case WIOCSTOP:
        case WIOCGSTAT:
                lock_kernel();
-               rval = wd_ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
+               rval = cpwd_ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
                unlock_kernel();
                break;
+
        /* everything else is handled by the generic compat layer */
        default:
                break;
@@ -419,440 +493,203 @@ static long wd_compat_ioctl(struct file *file, unsigned int cmd,
        return rval;
 }
 
-static ssize_t wd_write(struct file    *file, 
-                       const char      __user *buf, 
-                       size_t          count, 
-                       loff_t          *ppos)
+static ssize_t cpwd_write(struct file *file, const char __user *buf, 
+                         size_t count, loff_t *ppos)
 {
-       struct wd_timer* pTimer = (struct wd_timer*)file->private_data;
-
-       if(NULL == pTimer) {
-               return(-EINVAL);
-       }
+       struct inode *inode = file->f_path.dentry->d_inode;
+       struct cpwd *p = cpwd_device;
+       int index = iminor(inode);
 
        if (count) {
-               wd_pingtimer(pTimer);
+               cpwd_pingtimer(p, index);
                return 1;
        }
-       return 0;
-}
 
-static ssize_t wd_read(struct file * file, char __user *buffer,
-                       size_t count, loff_t *ppos)
-{
-#ifdef WD_DEBUG
-       wd_dumpregs();
-       return(0);
-#else
-       return(-EINVAL);
-#endif /* ifdef WD_DEBUG */
+       return 0;
 }
 
-static irqreturn_t wd_interrupt(int irq, void *dev_id)
+static ssize_t cpwd_read(struct file * file, char __user *buffer,
+                        size_t count, loff_t *ppos)
 {
-       /* 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 IRQ_HANDLED;
+       return -EINVAL;
 }
 
-static const struct file_operations wd_fops = {
+static const struct file_operations cpwd_fops = {
        .owner =        THIS_MODULE,
-       .ioctl =        wd_ioctl,
-       .compat_ioctl = wd_compat_ioctl,
-       .open =         wd_open,
-       .write =        wd_write,
-       .read =         wd_read,
-       .release =      wd_release,
+       .ioctl =        cpwd_ioctl,
+       .compat_ioctl = cpwd_compat_ioctl,
+       .open =         cpwd_open,
+       .write =        cpwd_write,
+       .read =         cpwd_read,
+       .release =      cpwd_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 };
-
-#ifdef WD_DEBUG
-static void wd_dumpregs(void)
+static int __devinit cpwd_probe(struct of_device *op,
+                               const struct of_device_id *match)
 {
-       /* 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 %p: 0x%x\n", 
-               wd_dev.regs + PLD_IMASK,
-               readb(wd_dev.regs + PLD_IMASK));
-       printk("\tpld_status at %p: 0x%x\n", 
-               wd_dev.regs + PLD_STATUS, 
-               readb(wd_dev.regs + PLD_STATUS));
-}
-#endif
-
-/* 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
- */
-static void wd_toggleintr(struct wd_timer* pTimer, int enable)
-{
-       unsigned char curregs = wd_readb(wd_dev.regs + PLD_IMASK);
-       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);
+       struct device_node *options;
+       const char *str_prop;
+       const void *prop_val;
+       int i, err = -EINVAL;
+       struct cpwd *p;
 
-       wd_writeb(curregs, wd_dev.regs + PLD_IMASK);
-       return;
-}
+       if (cpwd_device)
+               return -EINVAL;
 
-/* Reset countdown timer with 'limit' value and continue countdown.
- * This will not start a stopped timer.
- *
- * pTimer      - pointer to timer device
- */
-static void wd_pingtimer(struct wd_timer* pTimer)
-{
-       if (wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) {
-               wd_readw(pTimer->regs + WD_DCNTR);
+       p = kzalloc(sizeof(*p), GFP_KERNEL);
+       err = -ENOMEM;
+       if (!p) {
+               printk(KERN_ERR PFX "Unable to allocate struct cpwd.\n");
+               goto out;
        }
-}
 
-/* 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
- */
-static void wd_stoptimer(struct wd_timer* pTimer)
-{
-       if(wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) {
-               wd_toggleintr(pTimer, WD_INTR_OFF);
+       p->irq = op->irqs[0];
 
-               if(wd_dev.isbaddoggie) {
-                       pTimer->runstatus |= WD_STAT_BSTOP;
-                       wd_brokentimer((unsigned long)&wd_dev);
-               }
-       }
-}
+       spin_lock_init(&p->lock);
 
-/* 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
- */
-static void wd_starttimer(struct wd_timer* pTimer)
-{
-       if(wd_dev.isbaddoggie) {
-               pTimer->runstatus &= ~WD_STAT_BSTOP;
+       p->regs = of_ioremap(&op->resource[0], 0,
+                            4 * WD_TIMER_REGSZ, DRIVER_NAME);
+       if (!p->regs) {
+               printk(KERN_ERR PFX "Unable to map registers.\n");
+               goto out_free;
        }
-       pTimer->runstatus &= ~WD_STAT_SVCD;
 
-       wd_writew(pTimer->timeout, pTimer->regs + WD_LIMIT);
-       wd_toggleintr(pTimer, WD_INTR_ON);
-}
+       options = of_find_node_by_path("/options");
+       err = -ENODEV;
+       if (!options) {
+               printk(KERN_ERR PFX "Unable to find /options node.\n");
+               goto out_iounmap;
+       }
 
-/* Restarts timer with maximum limit value and
- * does not unset 'brokenstop' value.
- */
-static void wd_resetbrokentimer(struct wd_timer* pTimer)
-{
-       wd_toggleintr(pTimer, WD_INTR_ON);
-       wd_writew(WD_BLIMIT, pTimer->regs + WD_LIMIT);
-}
+       prop_val = of_get_property(options, "watchdog-enable?", NULL);
+       p->enabled = (prop_val ? true : false);
 
-/* Timer device initialization helper.
- * Returns 0 on success, other on failure
- */
-static int wd_inittimer(int whichdog)
-{
-       struct miscdevice                               *whichmisc;
-       void __iomem *whichregs;
-       char                                                    whichident[8];
-       int                                                             whichmask;
-       __u16                                                   whichlimit;
+       prop_val = of_get_property(options, "watchdog-reboot?", NULL);
+       p->reboot = (prop_val ? true : false);
 
-       switch(whichdog)
-       {
-               case WD0_ID:
-                       whichmisc = &wd0_miscdev;
-                       strcpy(whichident, "RIC");
-                       whichregs = wd_dev.regs + WD0_OFF;
-                       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_OFF;
-                       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_OFF;
-                       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, __func__, 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);
-}
+       str_prop = of_get_property(options, "watchdog-timeout", NULL);
+       if (str_prop)
+               p->timeout = simple_strtoul(str_prop, NULL, 10);
 
-/* 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.
- */
-static 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
+       /* CP1400s seem to have broken PLD implementations-- the
+        * interrupt_mask register cannot be written, so no timer
+        * interrupts can be masked within the PLD.
         */
-       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]);
+       str_prop = of_get_property(op->node, "model", NULL);
+       p->broken = (str_prop && !strcmp(str_prop, WD_BADMODEL));
+
+       if (!p->enabled)
+               cpwd_toggleintr(p, -1, WD_INTR_OFF);
+
+       for (i = 0; i < WD_NUMDEVS; i++) {
+               static const char *cpwd_names[] = { "RIC", "XIR", "POR" };
+               static int *parms[] = { &wd0_timeout,
+                                       &wd1_timeout,
+                                       &wd2_timeout };
+               struct miscdevice *mp = &p->devs[i].misc;
+
+               mp->minor = WD0_MINOR + i;
+               mp->name = cpwd_names[i];
+               mp->fops = &cpwd_fops;
+
+               p->devs[i].regs = p->regs + (i * WD_TIMER_REGSZ);
+               p->devs[i].intr_mask = (WD0_INTR_MASK << i);
+               p->devs[i].runstatus &= ~WD_STAT_BSTOP;
+               p->devs[i].runstatus |= WD_STAT_INIT;
+               p->devs[i].timeout = p->timeout;
+               if (*parms[i])
+                       p->devs[i].timeout = *parms[i];
+
+               err = misc_register(&p->devs[i].misc);
+               if (err) {
+                       printk(KERN_ERR "Could not register misc device for "
+                              "dev %d\n", i);
+                       goto out_unregister;
                }
        }
 
-       if(tripped) {
-               /* there is at least one timer brokenstopped-- reschedule */
-               init_timer(&wd_timer);
-               wd_timer.expires = WD_BTIMEOUT;
-               add_timer(&wd_timer);
+       if (p->broken) {
+               init_timer(&cpwd_timer);
+               cpwd_timer.function     = cpwd_brokentimer;
+               cpwd_timer.data         = (unsigned long) p;
+               cpwd_timer.expires      = WD_BTIMEOUT;
+
+               printk(KERN_INFO PFX "PLD defect workaround enabled for "
+                      "model " WD_BADMODEL ".\n");
        }
-}
 
-static int wd_getstatus(struct wd_timer* pTimer)
-{
-       unsigned char stat = wd_readb(pTimer->regs + WD_STATUS);
-       unsigned char intr = wd_readb(wd_dev.regs + PLD_IMASK);
-       unsigned char ret  = WD_STOPPED;
+       dev_set_drvdata(&op->dev, p);
+       cpwd_device = p;
+       err = 0;
 
-       /* 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;
-                       }
-               }
-       }
+out:
+       return err;
 
-       /* determine SERVICED */
-       if(pTimer->runstatus & WD_STAT_SVCD) {
-               ret |= WD_SERVICED;
-       }
+out_unregister:
+       for (i--; i >= 0; i--)
+               misc_deregister(&p->devs[i].misc);
 
-       return(ret);
+out_iounmap:
+       of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
+
+out_free:
+       kfree(p);
+       goto out;
 }
 
-static int __init wd_init(void)
+static int __devexit cpwd_remove(struct of_device *op)
 {
-       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->ofdev.node->name, WD_OBPNAME))
-                               goto ebus_done;
+       struct cpwd *p = dev_get_drvdata(&op->dev);
+       int i;
+
+       for (i = 0; i < 4; i++) {
+               misc_deregister(&p->devs[i].misc);
+
+               if (!p->enabled) {
+                       cpwd_stoptimer(p, i);
+                       if (p->devs[i].runstatus & WD_STAT_BSTOP)
+                               cpwd_resetbrokentimer(p, i);
                }
        }
 
-ebus_done:
-       if(!edev) {
-               printk("%s: unable to locate device\n", WD_OBPNAME);
-               return -ENODEV;
-       }
+       if (p->broken)
+               del_timer_sync(&cpwd_timer);
 
-       wd_dev.regs = 
-               ioremap(edev->resource[0].start, 4 * WD_TIMER_REGSZ); /* ? */
+       if (p->initialized)
+               free_irq(p->irq, p);
 
-       if(NULL == wd_dev.regs) {
-               printk("%s: unable to map registers\n", WD_OBPNAME);
-               return(-ENODEV);
-       }
+       of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ);
+       kfree(p);
 
-       /* 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();
+       cpwd_device = NULL;
 
-       /* disable all interrupts unless watchdog-enabled? == true */
-       if(! wd_dev.opt_enable) {
-               wd_toggleintr(NULL, WD_INTR_OFF);
-       }
+       return 0;
+}
 
-       /* 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);
-               }
-       }
+static struct of_device_id cpwd_match[] = {
+       {
+               .name = "watchdog",
+       },
+       {},
+};
+MODULE_DEVICE_TABLE(of, cpwd_match);
 
-       /* 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;
+static struct of_platform_driver cpwd_driver = {
+       .name           = DRIVER_NAME,
+       .match_table    = cpwd_match,
+       .probe          = cpwd_probe,
+       .remove         = __devexit_p(cpwd_remove),
+};
 
-               printk("%s: PLD defect workaround enabled for model %s\n",
-                       WD_OBPNAME, WD_BADMODEL);
-       }
-       return(0);
+static int __init cpwd_init(void)
+{
+       return of_register_driver(&cpwd_driver, &of_bus_type);
 }
 
-static void __exit wd_cleanup(void)
+static void __exit cpwd_exit(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 + WD_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 + WD_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);
+       of_unregister_driver(&cpwd_driver);
 }
 
-module_init(wd_init);
-module_exit(wd_cleanup);
+module_init(cpwd_init);
+module_exit(cpwd_exit);