[WATCHDOG] Final 2.4 changes for wdt_pci.c

drivers/char/watchdog/wdt_pci.c

@@ -30,7 +30,9 @@
  *		Alan Cox	:	Split ISA and PCI cards into two drivers
  *		Jeff Garzik	:	PCI cleanups
  *		Tigran Aivazian	:	Restructured wdtpci_init_one() to handle failures
- *		Matt Domsch	:	added nowayout and timeout module options
+ *		Joel Becker 	:	Added WDIOC_GET/SETTIMEOUT
+ *		Zwane Mwaikambo	:	Magic char closing, locking changes, cleanups
+ *		Matt Domsch	:	nowayout module option
  */
 
 #include <linux/config.h>
@@ -67,23 +69,18 @@
 #define PCI_DEVICE_ID_WDG_CSM 0x22c0
 #endif
 
-static unsigned long wdt_is_open;
+static struct semaphore open_sem;
+static spinlock_t wdtpci_lock;
 static int expect_close = 0;
 
-/*
- *	You must set these - there is no sane way to probe for this board.
- *	You can use wdt=x,y to set these now.
- */
- 
-static int io=0x240;
-static int irq=11;
+static int io;
+static int irq;
 
+/* Default timeout */
 #define WD_TIMO (100*60)		/* 1 minute */
+#define WD_TIMO_MAX (WD_TIMO*60)	/* 1 hour(?) */
 
-static int timeout_val = WD_TIMO;	/* value passed to card */
-static int timeout = 60;	        /* in seconds */
-MODULE_PARM(timeout,"i");
-MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default=60)");
+static int wd_margin = WD_TIMO;
 
 #ifdef CONFIG_WATCHDOG_NOWAYOUT
 static int nowayout = 1;
@@ -94,43 +91,6 @@ static int nowayout = 0;
 MODULE_PARM(nowayout,"i");
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 
-static void __init
-wdtpci_validate_timeout(void)
-{
-	timeout_val = timeout * 100;
-}
-
-#ifndef MODULE
-
-/**
- *	wdtpci_setup:
- *	@str: command line string
- *
- *	Setup options. The board isn't really probe-able so we have to
- *	get the user to tell us the configuration. Sane people build it 
- *	modular but the others come here.
- */
- 
-static int __init wdtpci_setup(char *str)
-{
-	int ints[4];
-
-	str = get_options (str, ARRAY_SIZE(ints), ints);
-
-	if (ints[0] > 0)
-	{
-		io = ints[1];
-		if(ints[0] > 1)
-			irq = ints[2];
-	}
-
-	return 1;
-}
-
-__setup("wdt=", wdtpci_setup);
-
-#endif /* !MODULE */
- 
 /*
  *	Programming support
  */
@@ -246,11 +206,15 @@ static void wdtpci_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  
 static void wdtpci_ping(void)
 {
+	unsigned long flags;
+
 	/* Write a watchdog value */
+	spin_lock_irqsave(&wdtpci_lock, flags);
 	inb_p(WDT_DC);
 	wdtpci_ctr_mode(1,2);
-	wdtpci_ctr_load(1,timeout_val);		/* Timeout */
+	wdtpci_ctr_load(1,wd_margin);		/* Timeout */
 	outb_p(0, WDT_DC);
+	spin_unlock_irqrestore(&wdtpci_lock, flags);
 }
 
 /**
@@ -270,10 +234,12 @@ static ssize_t wdtpci_write(struct file *file, const char *buf, size_t count, lo
 	if (ppos != &file->f_pos)
 		return -ESPIPE;
 
-	if(count)
-	{
+	if (count) {
 		if (!nowayout) {
 			size_t i;
+
+			expect_close = 0;
+
 			for (i = 0; i != count; i++) {
 				char c;
 				if(get_user(c, buf+i))
@@ -283,9 +249,9 @@ static ssize_t wdtpci_write(struct file *file, const char *buf, size_t count, lo
 			}
 		}
 		wdtpci_ping();
-		return 1;
 	}
-	return 0;
+
+	return count;
 }
 
 /**
@@ -337,6 +303,7 @@ static ssize_t wdtpci_read(struct file *file, char *buf, size_t count, loff_t *p
 static int wdtpci_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 	unsigned long arg)
 {
+	int new_margin;
 	static struct watchdog_info ident = {
 		.options	= WDIOF_OVERHEAT  | WDIOF_POWERUNDER |
 				  WDIOF_POWEROVER | WDIOF_EXTERN1 |
@@ -361,6 +328,18 @@ static int wdtpci_ioctl(struct inode *inode, struct file *file, unsigned int cmd
 		case WDIOC_KEEPALIVE:
 			wdtpci_ping();
 			return 0;
+		case WDIOC_SETTIMEOUT:
+			if (get_user(new_margin, (int *)arg))
+				return -EFAULT;
+			/* Arbitrary, can't find the card's limits */
+			new_margin *= 100;
+			if ((new_margin < 0) || (new_margin > WD_TIMO_MAX))
+				return -EINVAL;
+			wd_margin = new_margin;
+			wdtpci_ping();
+			/* Fall */
+		case WDIOC_GETTIMEOUT:
+			return put_user(wd_margin / 100, (int *)arg);
 	}
 }
 
@@ -378,19 +357,21 @@ static int wdtpci_ioctl(struct inode *inode, struct file *file, unsigned int cmd
  
 static int wdtpci_open(struct inode *inode, struct file *file)
 {
+	unsigned long flags;
+
 	switch(minor(inode->i_rdev))
 	{
 		case WATCHDOG_MINOR:
-			if( test_and_set_bit(0,&wdt_is_open) ) 
-			{
+			if (down_trylock(&open_sem))
 				return -EBUSY;
-			}
+
 			if (nowayout) {
 				MOD_INC_USE_COUNT;
 			}
 			/*
 			 *	Activate 
 			 */
+			spin_lock_irqsave(&wdtpci_lock, flags);
 			
 			inb_p(WDT_DC);		/* Disable */
 
@@ -413,9 +394,10 @@ static int wdtpci_open(struct inode *inode, struct file *file)
 			wdtpci_ctr_mode(1,2);
 			wdtpci_ctr_mode(2,1);
 			wdtpci_ctr_load(0,20833);	/* count at 100Hz */
-			wdtpci_ctr_load(1,timeout_val); /* Timeout */
+			wdtpci_ctr_load(1,wd_margin);/* Timeout 60 seconds */
 			/* DO NOT LOAD CTR2 on PCI card! -- JPN */
 			outb_p(0, WDT_DC);	/* Enable */
+			spin_unlock_irqrestore(&wdtpci_lock, flags);
 			return 0;
 		case TEMP_MINOR:
 			return 0;
@@ -438,13 +420,19 @@ static int wdtpci_open(struct inode *inode, struct file *file)
  
 static int wdtpci_release(struct inode *inode, struct file *file)
 {
-	if(minor(inode->i_rdev)==WATCHDOG_MINOR)
-	{
-		if (!nowayout) {
+
+	if (minor(inode->i_rdev)==WATCHDOG_MINOR) {
+		unsigned long flags;
+		if (expect_close) {
+			spin_lock_irqsave(&wdtpci_lock, flags);
 			inb_p(WDT_DC);		/* Disable counters */
 			wdtpci_ctr_load(2,0);	/* 0 length reset pulses now */
+			spin_unlock_irqrestore(&wdtpci_lock, flags);
+		} else {
+			printk(KERN_CRIT PFX "Unexpected close, not stopping timer!");
+			wdtpci_ping();
 		}
-		clear_bit(0, &wdt_is_open );
+		up(&open_sem);
 	}
 	return 0;
 }
@@ -464,11 +452,14 @@ static int wdtpci_release(struct inode *inode, struct file *file)
 static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
 	void *unused)
 {
-	if(code==SYS_DOWN || code==SYS_HALT)
-	{
+	unsigned long flags;
+
+	if (code==SYS_DOWN || code==SYS_HALT) {
 		/* Turn the card off */
+		spin_lock_irqsave(&wdtpci_lock, flags);
 		inb_p(WDT_DC);
 		wdtpci_ctr_load(2,0);
+		spin_unlock_irqrestore(&wdtpci_lock, flags);
 	}
 	return NOTIFY_DONE;
 }
@@ -528,6 +519,9 @@ static int __init wdtpci_init_one (struct pci_dev *dev,
 	if (pci_enable_device (dev))
 		goto out;
 
+	sema_init(&open_sem, 1);
+	spin_lock_init(&wdtpci_lock);
+
 	irq = dev->irq;
 	io = pci_resource_start (dev, 2);
 	printk ("WDT501-P(PCI-WDG-CSM) driver 0.07 at %X "
@@ -646,8 +640,6 @@ static int __init wdtpci_init(void)
 	if (rc < 1)
 		return -ENODEV;
 	
-	wdtpci_validate_timeout();
-	
 	return 0;
 }