1 files changed, 163 insertions, 320 deletions

diff --git a/drivers/watchdog/shwdt.c b/drivers/watchdog/shwdt.c
index 6fc74065abe..061756e36cf 100644
--- a/drivers/watchdog/shwdt.c
+++ b/drivers/watchdog/shwdt.c
@@ -1,9 +1,9 @@
 /*
- * drivers/char/watchdog/shwdt.c
+ * drivers/watchdog/shwdt.c
  *
  * Watchdog driver for integrated watchdog in the SuperH processors.
  *
- * Copyright (C) 2001, 2002, 2003 Paul Mundt <lethal@linux-sh.org>
+ * Copyright (C) 2001 - 2012  Paul Mundt <lethal@linux-sh.org>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
@@ -17,22 +17,26 @@
  *     Added expect close support, made emulated timeout runtime changeable
  *     general cleanups, add some ioctls
  */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/moduleparam.h>
+#include <linux/platform_device.h>
 #include <linux/init.h>
 #include <linux/types.h>
-#include <linux/miscdevice.h>
+#include <linux/spinlock.h>
 #include <linux/watchdog.h>
-#include <linux/reboot.h>
-#include <linux/notifier.h>
-#include <linux/ioport.h>
+#include <linux/pm_runtime.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
+#include <linux/slab.h>
 #include <linux/io.h>
-#include <linux/uaccess.h>
+#include <linux/clk.h>
+#include <linux/err.h>
 #include <asm/watchdog.h>
 
-#define PFX "shwdt: "
+#define DRV_NAME "sh-wdt"
 
 /*
  * Default clock division ratio is 5.25 msecs. For an additional table of
@@ -48,7 +52,7 @@
  * necssary.
  *
  * As a result of this timing problem, the only modes that are particularly
- * feasible are the 4096 and the 2048 divisors, which yeild 5.25 and 2.62ms
+ * feasible are the 4096 and the 2048 divisors, which yield 5.25 and 2.62ms
  * overflow periods respectively.
  *
  * Also, since we can't really expect userspace to be responsive enough
@@ -62,37 +66,35 @@
  * misses its deadline, the kernel timer will allow the WDT to overflow.
  */
 static int clock_division_ratio = WTCSR_CKS_4096;
-
-#define next_ping_period(cks)	msecs_to_jiffies(cks - 4)
-
-static void sh_wdt_ping(unsigned long data);
-
-static unsigned long shwdt_is_open;
-static const struct watchdog_info sh_wdt_info;
-static char shwdt_expect_close;
-static DEFINE_TIMER(timer, sh_wdt_ping, 0, 0);
-static unsigned long next_heartbeat;
-static DEFINE_SPINLOCK(shwdt_lock);
+#define next_ping_period(cks)	(jiffies + msecs_to_jiffies(cks - 4))
 
 #define WATCHDOG_HEARTBEAT 30			/* 30 sec default heartbeat */
 static int heartbeat = WATCHDOG_HEARTBEAT;	/* in seconds */
+static bool nowayout = WATCHDOG_NOWAYOUT;
+static unsigned long next_heartbeat;
 
-static int nowayout = WATCHDOG_NOWAYOUT;
+struct sh_wdt {
+	void __iomem		*base;
+	struct device		*dev;
+	struct clk		*clk;
+	spinlock_t		lock;
 
-/**
- * 	sh_wdt_start - Start the Watchdog
- *
- * 	Starts the watchdog.
- */
-static void sh_wdt_start(void)
+	struct timer_list	timer;
+};
+
+static int sh_wdt_start(struct watchdog_device *wdt_dev)
 {
-	__u8 csr;
+	struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
 	unsigned long flags;
+	u8 csr;
+
+	pm_runtime_get_sync(wdt->dev);
+	clk_enable(wdt->clk);
 
-	spin_lock_irqsave(&shwdt_lock, flags);
+	spin_lock_irqsave(&wdt->lock, flags);
 
 	next_heartbeat = jiffies + (heartbeat * HZ);
-	mod_timer(&timer, next_ping_period(clock_division_ratio));
+	mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
 
 	csr = sh_wdt_read_csr();
 	csr |= WTCSR_WT | clock_division_ratio;
@@ -114,84 +116,73 @@ static void sh_wdt_start(void)
 	sh_wdt_write_csr(csr);
 
 #ifdef CONFIG_CPU_SH2
-	/*
-	 * Whoever came up with the RSTCSR semantics must've been smoking
-	 * some of the good stuff, since in addition to the WTCSR/WTCNT write
-	 * brain-damage, it's managed to fuck things up one step further..
-	 *
-	 * If we need to clear the WOVF bit, the upper byte has to be 0xa5..
-	 * but if we want to touch RSTE or RSTS, the upper byte has to be
-	 * 0x5a..
-	 */
 	csr = sh_wdt_read_rstcsr();
 	csr &= ~RSTCSR_RSTS;
 	sh_wdt_write_rstcsr(csr);
 #endif
-	spin_unlock_irqrestore(&shwdt_lock, flags);
+	spin_unlock_irqrestore(&wdt->lock, flags);
+
+	return 0;
 }
 
-/**
- * 	sh_wdt_stop - Stop the Watchdog
- * 	Stops the watchdog.
- */
-static void sh_wdt_stop(void)
+static int sh_wdt_stop(struct watchdog_device *wdt_dev)
 {
-	__u8 csr;
+	struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
 	unsigned long flags;
+	u8 csr;
 
-	spin_lock_irqsave(&shwdt_lock, flags);
+	spin_lock_irqsave(&wdt->lock, flags);
 
-	del_timer(&timer);
+	del_timer(&wdt->timer);
 
 	csr = sh_wdt_read_csr();
 	csr &= ~WTCSR_TME;
 	sh_wdt_write_csr(csr);
-	spin_unlock_irqrestore(&shwdt_lock, flags);
+
+	spin_unlock_irqrestore(&wdt->lock, flags);
+
+	clk_disable(wdt->clk);
+	pm_runtime_put_sync(wdt->dev);
+
+	return 0;
 }
 
-/**
- * 	sh_wdt_keepalive - Keep the Userspace Watchdog Alive
- * 	The Userspace watchdog got a KeepAlive: schedule the next heartbeat.
- */
-static inline void sh_wdt_keepalive(void)
+static int sh_wdt_keepalive(struct watchdog_device *wdt_dev)
 {
+	struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
 	unsigned long flags;
 
-	spin_lock_irqsave(&shwdt_lock, flags);
+	spin_lock_irqsave(&wdt->lock, flags);
 	next_heartbeat = jiffies + (heartbeat * HZ);
-	spin_unlock_irqrestore(&shwdt_lock, flags);
+	spin_unlock_irqrestore(&wdt->lock, flags);
+
+	return 0;
 }
 
-/**
- * 	sh_wdt_set_heartbeat - Set the Userspace Watchdog heartbeat
- * 	Set the Userspace Watchdog heartbeat
- */
-static int sh_wdt_set_heartbeat(int t)
+static int sh_wdt_set_heartbeat(struct watchdog_device *wdt_dev, unsigned t)
 {
+	struct sh_wdt *wdt = watchdog_get_drvdata(wdt_dev);
 	unsigned long flags;
 
 	if (unlikely(t < 1 || t > 3600)) /* arbitrary upper limit */
 		return -EINVAL;
 
-	spin_lock_irqsave(&shwdt_lock, flags);
+	spin_lock_irqsave(&wdt->lock, flags);
 	heartbeat = t;
-	spin_unlock_irqrestore(&shwdt_lock, flags);
+	wdt_dev->timeout = t;
+	spin_unlock_irqrestore(&wdt->lock, flags);
+
 	return 0;
 }
 
-/**
- * 	sh_wdt_ping - Ping the Watchdog
- *	@data: Unused
- *
- * 	Clears overflow bit, resets timer counter.
- */
 static void sh_wdt_ping(unsigned long data)
 {
+	struct sh_wdt *wdt = (struct sh_wdt *)data;
 	unsigned long flags;
 
-	spin_lock_irqsave(&shwdt_lock, flags);
+	spin_lock_irqsave(&wdt->lock, flags);
 	if (time_before(jiffies, next_heartbeat)) {
-		__u8 csr;
+		u8 csr;
 
 		csr = sh_wdt_read_csr();
 		csr &= ~WTCSR_IOVF;
@@ -199,299 +190,154 @@ static void sh_wdt_ping(unsigned long data)
 
 		sh_wdt_write_cnt(0);
 
-		mod_timer(&timer, next_ping_period(clock_division_ratio));
+		mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
 	} else
-		printk(KERN_WARNING PFX "Heartbeat lost! Will not ping "
-		       "the watchdog\n");
-	spin_unlock_irqrestore(&shwdt_lock, flags);
+		dev_warn(wdt->dev, "Heartbeat lost! Will not ping "
+		         "the watchdog\n");
+	spin_unlock_irqrestore(&wdt->lock, flags);
 }
 
-/**
- * 	sh_wdt_open - Open the Device
- * 	@inode: inode of device
- * 	@file: file handle of device
- *
- * 	Watchdog device is opened and started.
- */
-static int sh_wdt_open(struct inode *inode, struct file *file)
-{
-	if (test_and_set_bit(0, &shwdt_is_open))
-		return -EBUSY;
-	if (nowayout)
-		__module_get(THIS_MODULE);
+static const struct watchdog_info sh_wdt_info = {
+	.options		= WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
+				  WDIOF_MAGICCLOSE,
+	.firmware_version	= 1,
+	.identity		= "SH WDT",
+};
 
-	sh_wdt_start();
+static const struct watchdog_ops sh_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= sh_wdt_start,
+	.stop		= sh_wdt_stop,
+	.ping		= sh_wdt_keepalive,
+	.set_timeout	= sh_wdt_set_heartbeat,
+};
 
-	return nonseekable_open(inode, file);
-}
+static struct watchdog_device sh_wdt_dev = {
+	.info	= &sh_wdt_info,
+	.ops	= &sh_wdt_ops,
+};
 
-/**
- * 	sh_wdt_close - Close the Device
- * 	@inode: inode of device
- * 	@file: file handle of device
- *
- * 	Watchdog device is closed and stopped.
- */
-static int sh_wdt_close(struct inode *inode, struct file *file)
+static int sh_wdt_probe(struct platform_device *pdev)
 {
-	if (shwdt_expect_close == 42) {
-		sh_wdt_stop();
-	} else {
-		printk(KERN_CRIT PFX "Unexpected close, not "
-		       "stopping watchdog!\n");
-		sh_wdt_keepalive();
-	}
+	struct sh_wdt *wdt;
+	struct resource *res;
+	int rc;
 
-	clear_bit(0, &shwdt_is_open);
-	shwdt_expect_close = 0;
+	/*
+	 * As this driver only covers the global watchdog case, reject
+	 * any attempts to register per-CPU watchdogs.
+	 */
+	if (pdev->id != -1)
+		return -EINVAL;
 
-	return 0;
-}
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(!res))
+		return -EINVAL;
 
-/**
- * 	sh_wdt_write - Write to Device
- * 	@file: file handle of device
- * 	@buf: buffer to write
- * 	@count: length of buffer
- * 	@ppos: offset
- *
- * 	Pings the watchdog on write.
- */
-static ssize_t sh_wdt_write(struct file *file, const char *buf,
-			    size_t count, loff_t *ppos)
-{
-	if (count) {
-		if (!nowayout) {
-			size_t i;
-
-			shwdt_expect_close = 0;
-
-			for (i = 0; i != count; i++) {
-				char c;
-				if (get_user(c, buf + i))
-					return -EFAULT;
-				if (c == 'V')
-					shwdt_expect_close = 42;
-			}
-		}
-		sh_wdt_keepalive();
+	wdt = devm_kzalloc(&pdev->dev, sizeof(struct sh_wdt), GFP_KERNEL);
+	if (unlikely(!wdt))
+		return -ENOMEM;
+
+	wdt->dev = &pdev->dev;
+
+	wdt->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(wdt->clk)) {
+		/*
+		 * Clock framework support is optional, continue on
+		 * anyways if we don't find a matching clock.
+		 */
+		wdt->clk = NULL;
 	}
 
-	return count;
-}
+	wdt->base = devm_ioremap_resource(wdt->dev, res);
+	if (IS_ERR(wdt->base))
+		return PTR_ERR(wdt->base);
 
-/**
- * 	sh_wdt_mmap - map WDT/CPG registers into userspace
- * 	@file: file structure for the device
- * 	@vma: VMA to map the registers into
- *
- * 	A simple mmap() implementation for the corner cases where the counter
- * 	needs to be mapped in userspace directly. Due to the relatively small
- * 	size of the area, neighbouring registers not necessarily tied to the
- * 	CPG will also be accessible through the register page, so this remains
- * 	configurable for users that really know what they're doing.
- *
- *	Additionaly, the register page maps in the CPG register base relative
- *	to the nearest page-aligned boundary, which requires that userspace do
- *	the appropriate CPU subtype math for calculating the page offset for
- *	the counter value.
- */
-static int sh_wdt_mmap(struct file *file, struct vm_area_struct *vma)
-{
-	int ret = -ENOSYS;
+	watchdog_set_nowayout(&sh_wdt_dev, nowayout);
+	watchdog_set_drvdata(&sh_wdt_dev, wdt);
 
-#ifdef CONFIG_SH_WDT_MMAP
-	unsigned long addr;
+	spin_lock_init(&wdt->lock);
 
-	/* Only support the simple cases where we map in a register page. */
-	if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
-		return -EINVAL;
+	rc = sh_wdt_set_heartbeat(&sh_wdt_dev, heartbeat);
+	if (unlikely(rc)) {
+		/* Default timeout if invalid */
+		sh_wdt_set_heartbeat(&sh_wdt_dev, WATCHDOG_HEARTBEAT);
 
-	/*
-	 * Pick WTCNT as the start, it's usually the first register after the
-	 * FRQCR, and neither one are generally page-aligned out of the box.
-	 */
-	addr = WTCNT & ~(PAGE_SIZE - 1);
+		dev_warn(&pdev->dev,
+			 "heartbeat value must be 1<=x<=3600, using %d\n",
+			 sh_wdt_dev.timeout);
+	}
 
-	vma->vm_flags |= VM_IO;
-	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	dev_info(&pdev->dev, "configured with heartbeat=%d sec (nowayout=%d)\n",
+		 sh_wdt_dev.timeout, nowayout);
 
-	if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
-			       PAGE_SIZE, vma->vm_page_prot)) {
-		printk(KERN_ERR PFX "%s: io_remap_pfn_range failed\n",
-		       __func__);
-		return -EAGAIN;
+	rc = watchdog_register_device(&sh_wdt_dev);
+	if (unlikely(rc)) {
+		dev_err(&pdev->dev, "Can't register watchdog (err=%d)\n", rc);
+		return rc;
 	}
 
-	ret = 0;
-#endif
+	init_timer(&wdt->timer);
+	wdt->timer.function	= sh_wdt_ping;
+	wdt->timer.data		= (unsigned long)wdt;
+	wdt->timer.expires	= next_ping_period(clock_division_ratio);
 
-	return ret;
-}
+	dev_info(&pdev->dev, "initialized.\n");
+
+	pm_runtime_enable(&pdev->dev);
 
-/**
- * 	sh_wdt_ioctl - Query Device
- * 	@file: file handle of device
- * 	@cmd: watchdog command
- * 	@arg: argument
- *
- * 	Query basic information from the device or ping it, as outlined by the
- * 	watchdog API.
- */
-static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
-							unsigned long arg)
-{
-	int new_heartbeat;
-	int options, retval = -EINVAL;
-
-	switch (cmd) {
-	case WDIOC_GETSUPPORT:
-		return copy_to_user((struct watchdog_info *)arg,
-			  &sh_wdt_info, sizeof(sh_wdt_info)) ? -EFAULT : 0;
-	case WDIOC_GETSTATUS:
-	case WDIOC_GETBOOTSTATUS:
-		return put_user(0, (int *)arg);
-	case WDIOC_SETOPTIONS:
-		if (get_user(options, (int *)arg))
-			return -EFAULT;
-
-		if (options & WDIOS_DISABLECARD) {
-			sh_wdt_stop();
-			retval = 0;
-		}
-
-		if (options & WDIOS_ENABLECARD) {
-			sh_wdt_start();
-			retval = 0;
-		}
-
-		return retval;
-	case WDIOC_KEEPALIVE:
-		sh_wdt_keepalive();
-		return 0;
-	case WDIOC_SETTIMEOUT:
-		if (get_user(new_heartbeat, (int *)arg))
-			return -EFAULT;
-
-		if (sh_wdt_set_heartbeat(new_heartbeat))
-			return -EINVAL;
-
-		sh_wdt_keepalive();
-		/* Fall */
-	case WDIOC_GETTIMEOUT:
-		return put_user(heartbeat, (int *)arg);
-	default:
-		return -ENOTTY;
-	}
 	return 0;
 }
 
-/**
- * 	sh_wdt_notify_sys - Notifier Handler
- * 	@this: notifier block
- * 	@code: notifier event
- * 	@unused: unused
- *
- * 	Handles specific events, such as turning off the watchdog during a
- * 	shutdown event.
- */
-static int sh_wdt_notify_sys(struct notifier_block *this,
-			     unsigned long code, void *unused)
+static int sh_wdt_remove(struct platform_device *pdev)
 {
-	if (code == SYS_DOWN || code == SYS_HALT)
-		sh_wdt_stop();
+	watchdog_unregister_device(&sh_wdt_dev);
 
-	return NOTIFY_DONE;
-}
+	pm_runtime_disable(&pdev->dev);
 
-static const struct file_operations sh_wdt_fops = {
-	.owner		= THIS_MODULE,
-	.llseek		= no_llseek,
-	.write		= sh_wdt_write,
-	.unlocked_ioctl	= sh_wdt_ioctl,
-	.open		= sh_wdt_open,
-	.release	= sh_wdt_close,
-	.mmap		= sh_wdt_mmap,
-};
+	return 0;
+}
 
-static const struct watchdog_info sh_wdt_info = {
-	.options		= WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
-				  WDIOF_MAGICCLOSE,
-	.firmware_version	= 1,
-	.identity		= "SH WDT",
-};
+static void sh_wdt_shutdown(struct platform_device *pdev)
+{
+	sh_wdt_stop(&sh_wdt_dev);
+}
 
-static struct notifier_block sh_wdt_notifier = {
-	.notifier_call		= sh_wdt_notify_sys,
-};
+static struct platform_driver sh_wdt_driver = {
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
 
-static struct miscdevice sh_wdt_miscdev = {
-	.minor		= WATCHDOG_MINOR,
-	.name		= "watchdog",
-	.fops		= &sh_wdt_fops,
+	.probe		= sh_wdt_probe,
+	.remove		= sh_wdt_remove,
+	.shutdown	= sh_wdt_shutdown,
 };
 
-/**
- * 	sh_wdt_init - Initialize module
- * 	Registers the device and notifier handler. Actual device
- * 	initialization is handled by sh_wdt_open().
- */
 static int __init sh_wdt_init(void)
 {
-	int rc;
-
-	if (clock_division_ratio < 0x5 || clock_division_ratio > 0x7) {
+	if (unlikely(clock_division_ratio < 0x5 ||
+		     clock_division_ratio > 0x7)) {
 		clock_division_ratio = WTCSR_CKS_4096;
-		printk(KERN_INFO PFX
-		  "clock_division_ratio value must be 0x5<=x<=0x7, using %d\n",
-				clock_division_ratio);
-	}
-
-	rc = sh_wdt_set_heartbeat(heartbeat);
-	if (unlikely(rc)) {
-		heartbeat = WATCHDOG_HEARTBEAT;
-		printk(KERN_INFO PFX
-			"heartbeat value must be 1<=x<=3600, using %d\n",
-								heartbeat);
-	}
 
-	rc = register_reboot_notifier(&sh_wdt_notifier);
-	if (unlikely(rc)) {
-		printk(KERN_ERR PFX
-			"Can't register reboot notifier (err=%d)\n", rc);
-		return rc;
+		pr_info("divisor must be 0x5<=x<=0x7, using %d\n",
+			clock_division_ratio);
 	}
 
-	rc = misc_register(&sh_wdt_miscdev);
-	if (unlikely(rc)) {
-		printk(KERN_ERR PFX
-			"Can't register miscdev on minor=%d (err=%d)\n",
-						sh_wdt_miscdev.minor, rc);
-		unregister_reboot_notifier(&sh_wdt_notifier);
-		return rc;
-	}
-
-	printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
-		heartbeat, nowayout);
-
-	return 0;
+	return platform_driver_register(&sh_wdt_driver);
 }
 
-/**
- * 	sh_wdt_exit - Deinitialize module
- * 	Unregisters the device and notifier handler. Actual device
- * 	deinitialization is handled by sh_wdt_close().
- */
 static void __exit sh_wdt_exit(void)
 {
-	misc_deregister(&sh_wdt_miscdev);
-	unregister_reboot_notifier(&sh_wdt_notifier);
+	platform_driver_unregister(&sh_wdt_driver);
 }
+module_init(sh_wdt_init);
+module_exit(sh_wdt_exit);
 
 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
 MODULE_DESCRIPTION("SuperH watchdog driver");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform:" DRV_NAME);
 
 module_param(clock_division_ratio, int, 0);
 MODULE_PARM_DESC(clock_division_ratio,
@@ -503,10 +349,7 @@ MODULE_PARM_DESC(heartbeat,
 	"Watchdog heartbeat in seconds. (1 <= heartbeat <= 3600, default="
 				__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 
-module_param(nowayout, int, 0);
+module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout,
 	"Watchdog cannot be stopped once started (default="
 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
-
-module_init(sh_wdt_init);
-module_exit(sh_wdt_exit);