watchdog: xilinx: Convert driver to the watchdog framework

- Remove uneeded headers, fops functions
- Use xilinx_wdt prefix in start/stop/keepalive functions
  and in new structures

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/Kconfig

@@ -1026,6 +1026,7 @@ config M54xx_WATCHDOG
 config XILINX_WATCHDOG
 	tristate "Xilinx Watchdog timer"
 	depends on MICROBLAZE
+	select WATCHDOG_CORE
 	---help---
 	  Watchdog driver for the xps_timebase_wdt ip core.
 

drivers/watchdog/of_xilinx_wdt.c

@@ -1,6 +1,7 @@
 /*
  * Watchdog Device Driver for Xilinx axi/xps_timebase_wdt
  *
+ * (C) Copyright 2013 - 2014 Xilinx, Inc.
  * (C) Copyright 2011 (Alejandro Cabrera <aldaya@gmail.com>)
  *
  * This program is free software; you can redistribute it and/or
@@ -14,12 +15,9 @@
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/miscdevice.h>
 #include <linux/ioport.h>
 #include <linux/watchdog.h>
 #include <linux/io.h>
-#include <linux/uaccess.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_address.h>
@@ -47,22 +45,18 @@
 struct xwdt_device {
 	struct resource  res;
 	void __iomem *base;
-	u32 nowayout;
 	u32 wdt_interval;
-	u32 boot_status;
 };
 
 static struct xwdt_device xdev;
 
 static  u32 timeout;
 static  u32 control_status_reg;
-static  u8  expect_close;
 static  u8  no_timeout;
-static unsigned long driver_open;
 
 static  DEFINE_SPINLOCK(spinlock);
 
-static void xwdt_start(void)
+static int xilinx_wdt_start(struct watchdog_device *wdd)
 {
 	spin_lock(&spinlock);
 
@@ -76,9 +70,11 @@ static void xwdt_start(void)
 	iowrite32(XWT_CSRX_EWDT2_MASK, xdev.base + XWT_TWCSR1_OFFSET);
 
 	spin_unlock(&spinlock);
+
+	return 0;
 }
 
-static void xwdt_stop(void)
+static int xilinx_wdt_stop(struct watchdog_device *wdd)
 {
 	spin_lock(&spinlock);
 
@@ -91,9 +87,11 @@ static void xwdt_stop(void)
 
 	spin_unlock(&spinlock);
 	pr_info("Stopped!\n");
+
+	return 0;
 }
 
-static void xwdt_keepalive(void)
+static int xilinx_wdt_keepalive(struct watchdog_device *wdd)
 {
 	spin_lock(&spinlock);
 
@@ -102,23 +100,28 @@ static void xwdt_keepalive(void)
 	iowrite32(control_status_reg, xdev.base + XWT_TWCSR0_OFFSET);
 
 	spin_unlock(&spinlock);
-}
 
-static void xwdt_get_status(int *status)
-{
-	int new_status;
+	return 0;
+}
 
-	spin_lock(&spinlock);
+static const struct watchdog_info xilinx_wdt_ident = {
+	.options =  WDIOF_MAGICCLOSE |
+		    WDIOF_KEEPALIVEPING,
+	.firmware_version =	1,
+	.identity =	WATCHDOG_NAME,
+};
 
-	control_status_reg = ioread32(xdev.base + XWT_TWCSR0_OFFSET);
-	new_status = ((control_status_reg &
-			(XWT_CSR0_WRS_MASK | XWT_CSR0_WDS_MASK)) != 0);
-	spin_unlock(&spinlock);
+static const struct watchdog_ops xilinx_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = xilinx_wdt_start,
+	.stop = xilinx_wdt_stop,
+	.ping = xilinx_wdt_keepalive,
+};
 
-	*status = 0;
-	if (new_status & 1)
-		*status |= WDIOF_CARDRESET;
-}
+static struct watchdog_device xilinx_wdt_wdd = {
+	.info = &xilinx_wdt_ident,
+	.ops = &xilinx_wdt_ops,
+};
 
 static u32 xwdt_selftest(void)
 {
@@ -145,139 +148,6 @@ static u32 xwdt_selftest(void)
 		return XWT_TIMER_FAILED;
 }
 
-static int xwdt_open(struct inode *inode, struct file *file)
-{
-	/* Only one process can handle the wdt at a time */
-	if (test_and_set_bit(0, &driver_open))
-		return -EBUSY;
-
-	/* Make sure that the module are always loaded...*/
-	if (xdev.nowayout)
-		__module_get(THIS_MODULE);
-
-	xwdt_start();
-	pr_info("Started...\n");
-
-	return nonseekable_open(inode, file);
-}
-
-static int xwdt_release(struct inode *inode, struct file *file)
-{
-	if (expect_close == 42) {
-		xwdt_stop();
-	} else {
-		pr_crit("Unexpected close, not stopping watchdog!\n");
-		xwdt_keepalive();
-	}
-
-	clear_bit(0, &driver_open);
-	expect_close = 0;
-	return 0;
-}
-
-/*
- *      xwdt_write:
- *      @file: file handle to the watchdog
- *      @buf: buffer to write (unused as data does not matter here
- *      @count: count of bytes
- *      @ppos: pointer to the position to write. No seeks allowed
- *
- *      A write to a watchdog device is defined as a keepalive signal. Any
- *      write of data will do, as we don't define content meaning.
- */
-static ssize_t xwdt_write(struct file *file, const char __user *buf,
-						size_t len, loff_t *ppos)
-{
-	if (len) {
-		if (!xdev.nowayout) {
-			size_t i;
-
-			/* In case it was set long ago */
-			expect_close = 0;
-
-			for (i = 0; i != len; i++) {
-				char c;
-
-				if (get_user(c, buf + i))
-					return -EFAULT;
-				if (c == 'V')
-					expect_close = 42;
-			}
-		}
-		xwdt_keepalive();
-	}
-	return len;
-}
-
-static const struct watchdog_info ident = {
-	.options =  WDIOF_MAGICCLOSE |
-		    WDIOF_KEEPALIVEPING,
-	.firmware_version =	1,
-	.identity =	WATCHDOG_NAME,
-};
-
-/*
- *      xwdt_ioctl:
- *      @file: file handle to the device
- *      @cmd: watchdog command
- *      @arg: argument pointer
- *
- *      The watchdog API defines a common set of functions for all watchdogs
- *      according to their available features.
- */
-static long xwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
-	int status;
-
-	union {
-		struct watchdog_info __user *ident;
-		int __user *i;
-	} uarg;
-
-	uarg.i = (int __user *)arg;
-
-	switch (cmd) {
-	case WDIOC_GETSUPPORT:
-		return copy_to_user(uarg.ident, &ident,
-					sizeof(ident)) ? -EFAULT : 0;
-
-	case WDIOC_GETBOOTSTATUS:
-		return put_user(xdev.boot_status, uarg.i);
-
-	case WDIOC_GETSTATUS:
-		xwdt_get_status(&status);
-		return put_user(status, uarg.i);
-
-	case WDIOC_KEEPALIVE:
-		xwdt_keepalive();
-		return 0;
-
-	case WDIOC_GETTIMEOUT:
-		if (no_timeout)
-			return -ENOTTY;
-		else
-			return put_user(timeout, uarg.i);
-
-	default:
-		return -ENOTTY;
-	}
-}
-
-static const struct file_operations xwdt_fops = {
-	.owner      = THIS_MODULE,
-	.llseek     = no_llseek,
-	.write      = xwdt_write,
-	.open       = xwdt_open,
-	.release    = xwdt_release,
-	.unlocked_ioctl = xwdt_ioctl,
-};
-
-static struct miscdevice xwdt_miscdev = {
-	.minor      = WATCHDOG_MINOR,
-	.name       = "watchdog",
-	.fops       = &xwdt_fops,
-};
-
 static int xwdt_probe(struct platform_device *pdev)
 {
 	int rc;
@@ -313,7 +183,7 @@ static int xwdt_probe(struct platform_device *pdev)
 					"xlnx,wdt-enable-once", NULL);
 	if (tmptr == NULL) {
 		pr_warn("Parameter \"xlnx,wdt-enable-once\" not found in device tree!\n");
-		xdev.nowayout = WATCHDOG_NOWAYOUT;
+		watchdog_set_nowayout(&xilinx_wdt_wdd, true);
 	}
 
 /*
@@ -343,24 +213,14 @@ static int xwdt_probe(struct platform_device *pdev)
 		goto unmap_io;
 	}
 
-	xwdt_get_status(&xdev.boot_status);
-
-	rc = misc_register(&xwdt_miscdev);
+	rc = watchdog_register_device(&xilinx_wdt_wdd);
 	if (rc) {
-		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
-		       xwdt_miscdev.minor, rc);
+		pr_err("cannot register watchdog (err=%d)\n", rc);
 		goto unmap_io;
 	}
 
-	if (no_timeout)
-		pr_info("driver loaded (timeout=? sec, nowayout=%d)\n",
-			xdev.nowayout);
-	else
-		pr_info("driver loaded (timeout=%d sec, nowayout=%d)\n",
-			timeout, xdev.nowayout);
-
-	expect_close = 0;
-	clear_bit(0, &driver_open);
+	dev_info(&pdev->dev, "Xilinx Watchdog Timer at %p with timeout %ds\n",
+		 xdev.base, timeout);
 
 	return 0;
 
@@ -374,7 +234,7 @@ err_out:
 
 static int xwdt_remove(struct platform_device *dev)
 {
-	misc_deregister(&xwdt_miscdev);
+	watchdog_unregister_device(&xilinx_wdt_wdd);
 	iounmap(xdev.base);
 	release_mem_region(xdev.res.start, resource_size(&xdev.res));