1 files changed, 140 insertions, 78 deletions

diff --git a/drivers/char/watchdog/mv64x60_wdt.c b/drivers/char/watchdog/mv64x60_wdt.c
index b887cdb0133..0365c317f7e 100644
--- a/drivers/char/watchdog/mv64x60_wdt.c
+++ b/drivers/char/watchdog/mv64x60_wdt.c
@@ -23,61 +23,101 @@
 #include <linux/watchdog.h>
 #include <linux/platform_device.h>
 
-#include <asm/mv64x60.h>
+#include <linux/mv643xx.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
-/* MV64x60 WDC (config) register access definitions */
-#define MV64x60_WDC_CTL1_MASK	(3 << 24)
-#define MV64x60_WDC_CTL1(val)	((val & 3) << 24)
-#define MV64x60_WDC_CTL2_MASK	(3 << 26)
-#define MV64x60_WDC_CTL2(val)	((val & 3) << 26)
+#define MV64x60_WDT_WDC_OFFSET	0
+
+/*
+ * The watchdog configuration register contains a pair of 2-bit fields,
+ *   1.  a reload field, bits 27-26, which triggers a reload of
+ *       the countdown register, and
+ *   2.  an enable field, bits 25-24, which toggles between
+ *       enabling and disabling the watchdog timer.
+ * Bit 31 is a read-only field which indicates whether the
+ * watchdog timer is currently enabled.
+ *
+ * The low 24 bits contain the timer reload value.
+ */
+#define MV64x60_WDC_ENABLE_SHIFT	24
+#define MV64x60_WDC_SERVICE_SHIFT	26
+#define MV64x60_WDC_ENABLED_SHIFT	31
+
+#define MV64x60_WDC_ENABLED_TRUE	1
+#define MV64x60_WDC_ENABLED_FALSE	0
 
 /* Flags bits */
 #define MV64x60_WDOG_FLAG_OPENED	0
-#define MV64x60_WDOG_FLAG_ENABLED	1
 
 static unsigned long wdt_flags;
 static int wdt_status;
-static void __iomem *mv64x60_regs;
+static void __iomem *mv64x60_wdt_regs;
 static int mv64x60_wdt_timeout;
+static int mv64x60_wdt_count;
+static unsigned int bus_clk;
+static char expect_close;
+static DEFINE_SPINLOCK(mv64x60_wdt_spinlock);
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
-static void mv64x60_wdt_reg_write(u32 val)
+static int mv64x60_wdt_toggle_wdc(int enabled_predicate, int field_shift)
 {
-	/* Allow write only to CTL1 / CTL2 fields, retaining values in
-	 * other fields.
-	 */
-	u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
-	data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
-	data |= val;
-	writel(data, mv64x60_regs + MV64x60_WDT_WDC);
+	u32 data;
+	u32 enabled;
+	int ret = 0;
+
+	spin_lock(&mv64x60_wdt_spinlock);
+	data = readl(mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
+	enabled = (data >> MV64x60_WDC_ENABLED_SHIFT) & 1;
+
+	/* only toggle the requested field if enabled state matches predicate */
+	if ((enabled ^ enabled_predicate) == 0) {
+		/* We write a 1, then a 2 -- to the appropriate field */
+		data = (1 << field_shift) | mv64x60_wdt_count;
+		writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
+
+		data = (2 << field_shift) | mv64x60_wdt_count;
+		writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
+		ret = 1;
+	}
+	spin_unlock(&mv64x60_wdt_spinlock);
+
+	return ret;
 }
 
 static void mv64x60_wdt_service(void)
 {
-	/* Write 01 followed by 10 to CTL2 */
-	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
-	mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
+	mv64x60_wdt_toggle_wdc(MV64x60_WDC_ENABLED_TRUE,
+			       MV64x60_WDC_SERVICE_SHIFT);
+}
+
+static void mv64x60_wdt_handler_enable(void)
+{
+	if (mv64x60_wdt_toggle_wdc(MV64x60_WDC_ENABLED_FALSE,
+				   MV64x60_WDC_ENABLE_SHIFT)) {
+		mv64x60_wdt_service();
+		printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
+	}
 }
 
 static void mv64x60_wdt_handler_disable(void)
 {
-	if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
-		/* Write 01 followed by 10 to CTL1 */
-		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
-		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
+	if (mv64x60_wdt_toggle_wdc(MV64x60_WDC_ENABLED_TRUE,
+				   MV64x60_WDC_ENABLE_SHIFT))
 		printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
-	}
 }
 
-static void mv64x60_wdt_handler_enable(void)
+static void mv64x60_wdt_set_timeout(unsigned int timeout)
 {
-	if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
-		/* Write 01 followed by 10 to CTL1 */
-		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
-		mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
-		printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
-	}
+	/* maximum bus cycle count is 0xFFFFFFFF */
+	if (timeout > 0xFFFFFFFF / bus_clk)
+		timeout = 0xFFFFFFFF / bus_clk;
+
+	mv64x60_wdt_count = timeout * bus_clk >> 8;
+	mv64x60_wdt_timeout = timeout;
 }
 
 static int mv64x60_wdt_open(struct inode *inode, struct file *file)
@@ -85,21 +125,24 @@ static int mv64x60_wdt_open(struct inode *inode, struct file *file)
 	if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
 		return -EBUSY;
 
-	mv64x60_wdt_service();
-	mv64x60_wdt_handler_enable();
+	if (nowayout)
+		__module_get(THIS_MODULE);
 
-	nonseekable_open(inode, file);
+	mv64x60_wdt_handler_enable();
 
-	return 0;
+	return nonseekable_open(inode, file);
 }
 
 static int mv64x60_wdt_release(struct inode *inode, struct file *file)
 {
-	mv64x60_wdt_service();
-
-#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
-	mv64x60_wdt_handler_disable();
-#endif
+	if (expect_close == 42)
+		mv64x60_wdt_handler_disable();
+	else {
+		printk(KERN_CRIT
+		       "mv64x60_wdt: unexpected close, not stopping timer!\n");
+		mv64x60_wdt_service();
+	}
+	expect_close = 0;
 
 	clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
 
@@ -109,8 +152,22 @@ static int mv64x60_wdt_release(struct inode *inode, struct file *file)
 static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
 				 size_t len, loff_t * ppos)
 {
-	if (len)
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			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;
+			}
+		}
 		mv64x60_wdt_service();
+	}
 
 	return len;
 }
@@ -119,9 +176,12 @@ static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
 			     unsigned int cmd, unsigned long arg)
 {
 	int timeout;
+	int options;
 	void __user *argp = (void __user *)arg;
 	static struct watchdog_info info = {
-		.options = WDIOF_KEEPALIVEPING,
+		.options =	WDIOF_SETTIMEOUT	|
+				WDIOF_MAGICCLOSE	|
+				WDIOF_KEEPALIVEPING,
 		.firmware_version = 0,
 		.identity = "MV64x60 watchdog",
 	};
@@ -143,7 +203,15 @@ static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
 		return -EOPNOTSUPP;
 
 	case WDIOC_SETOPTIONS:
-		return -EOPNOTSUPP;
+		if (get_user(options, (int __user *)argp))
+			return -EFAULT;
+
+		if (options & WDIOS_DISABLECARD)
+			mv64x60_wdt_handler_disable();
+
+		if (options & WDIOS_ENABLECARD)
+			mv64x60_wdt_handler_enable();
+		break;
 
 	case WDIOC_KEEPALIVE:
 		mv64x60_wdt_service();
@@ -151,11 +219,13 @@ static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
 		break;
 
 	case WDIOC_SETTIMEOUT:
-		return -EOPNOTSUPP;
+		if (get_user(timeout, (int __user *)argp))
+			return -EFAULT;
+		mv64x60_wdt_set_timeout(timeout);
+		/* Fall through */
 
 	case WDIOC_GETTIMEOUT:
-		timeout = mv64x60_wdt_timeout * HZ;
-		if (put_user(timeout, (int __user *)argp))
+		if (put_user(mv64x60_wdt_timeout, (int __user *)argp))
 			return -EFAULT;
 		break;
 
@@ -184,18 +254,33 @@ static struct miscdevice mv64x60_wdt_miscdev = {
 static int __devinit mv64x60_wdt_probe(struct platform_device *dev)
 {
 	struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data;
-	int bus_clk = 133;
+	struct resource *r;
+	int timeout = 10;
 
-	mv64x60_wdt_timeout = 10;
+	bus_clk = 133;			/* in MHz */
 	if (pdata) {
-		mv64x60_wdt_timeout = pdata->timeout;
+		timeout = pdata->timeout;
 		bus_clk = pdata->bus_clk;
 	}
 
-	mv64x60_regs = mv64x60_get_bridge_vbase();
+	/* Since bus_clk is truncated MHz, actual frequency could be
+	 * up to 1MHz higher.  Round up, since it's better to time out
+	 * too late than too soon.
+	 */
+	bus_clk++;
+	bus_clk *= 1000000;		/* convert to Hz */
+
+	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+	if (!r)
+		return -ENODEV;
 
-	writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
-	       mv64x60_regs + MV64x60_WDT_WDC);
+	mv64x60_wdt_regs = ioremap(r->start, r->end - r->start + 1);
+	if (mv64x60_wdt_regs == NULL)
+		return -ENOMEM;
+
+	mv64x60_wdt_set_timeout(timeout);
+
+	mv64x60_wdt_handler_disable();	/* in case timer was already running */
 
 	return misc_register(&mv64x60_wdt_miscdev);
 }
@@ -204,9 +289,10 @@ static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
 {
 	misc_deregister(&mv64x60_wdt_miscdev);
 
-	mv64x60_wdt_service();
 	mv64x60_wdt_handler_disable();
 
+	iounmap(mv64x60_wdt_regs);
+
 	return 0;
 }
 
@@ -219,40 +305,16 @@ static struct platform_driver mv64x60_wdt_driver = {
 	},
 };
 
-static struct platform_device *mv64x60_wdt_dev;
-
 static int __init mv64x60_wdt_init(void)
 {
-	int ret;
-
 	printk(KERN_INFO "MV64x60 watchdog driver\n");
 
-	mv64x60_wdt_dev = platform_device_alloc(MV64x60_WDT_NAME, -1);
-	if (!mv64x60_wdt_dev) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	ret = platform_device_add(mv64x60_wdt_dev);
-	if (ret) {
-		platform_device_put(mv64x60_wdt_dev);
-		goto out;
-	}
-
-	ret = platform_driver_register(&mv64x60_wdt_driver);
-	if (ret) {
-		platform_device_unregister(mv64x60_wdt_dev);
-		goto out;
-	}
-
- out:
-	return ret;
+	return platform_driver_register(&mv64x60_wdt_driver);
 }
 
 static void __exit mv64x60_wdt_exit(void)
 {
 	platform_driver_unregister(&mv64x60_wdt_driver);
-	platform_device_unregister(mv64x60_wdt_dev);
 }
 
 module_init(mv64x60_wdt_init);