watchdog: Convert max63xx_wdt driver to watchdog framework

This patch converts max63xx_wdt driver to watchdog framework.
Also use devm_* APIs to save a few error handling code.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

2 files changed, 32 insertions, 159 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c83a83fe0398..8f5c31763286 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -330,6 +330,7 @@ config TS72XX_WATCHDOG
 config MAX63XX_WATCHDOG
         tristate "Max63xx watchdog"
         depends on ARM && HAS_IOMEM
+        select WATCHDOG_CORE
         help
           Support for memory mapped max63{69,70,71,72,73,74} watchdog timer.
 
diff --git a/drivers/watchdog/max63xx_wdt.c b/drivers/watchdog/max63xx_wdt.c
index c9e9ff2a9c9d..8f4a74e91619 100644
--- a/drivers/watchdog/max63xx_wdt.c
+++ b/drivers/watchdog/max63xx_wdt.c
@@ -18,22 +18,19 @@
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
-#include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/init.h>
 #include <linux/bitops.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
-#include <linux/uaccess.h>
 #include <linux/io.h>
-#include <linux/device.h>
 #include <linux/slab.h>
 
 #define DEFAULT_HEARTBEAT 60
 #define MAX_HEARTBEAT     60
 
-static int heartbeat = DEFAULT_HEARTBEAT;
+static unsigned int heartbeat = DEFAULT_HEARTBEAT;
 static bool nowayout  = WATCHDOG_NOWAYOUT;
 
 /*
@@ -45,15 +42,8 @@ static bool nowayout  = WATCHDOG_NOWAYOUT;
 
 static DEFINE_SPINLOCK(io_lock);
 
-static unsigned long wdt_status;
-#define WDT_IN_USE      0
-#define WDT_RUNNING     1
-#define WDT_OK_TO_CLOSE 2
-
 static int nodelay;
-static struct resource  *wdt_mem;
 static void __iomem     *wdt_base;
-static struct platform_device *max63xx_pdev;
 
 /*
  * The timeout values used are actually the absolute minimum the chip
@@ -117,7 +107,7 @@ max63xx_select_timeout(struct max63xx_timeout *table, int value)
         return NULL;
 }
 
-static void max63xx_wdt_ping(void)
+static int max63xx_wdt_ping(struct watchdog_device *wdd)
 {
         u8 val;
 
@@ -129,15 +119,14 @@ static void max63xx_wdt_ping(void)
         __raw_writeb(val & ~MAX6369_WDI, wdt_base);
 
         spin_unlock(&io_lock);
+        return 0;
 }
 
-static void max63xx_wdt_enable(struct max63xx_timeout *entry)
+static int max63xx_wdt_start(struct watchdog_device *wdd)
 {
+        struct max63xx_timeout *entry = watchdog_get_drvdata(wdd);
         u8 val;
 
-        if (test_and_set_bit(WDT_RUNNING, &wdt_status))
-                return;
-
         spin_lock(&io_lock);
 
         val = __raw_readb(wdt_base);
@@ -149,10 +138,11 @@ static void max63xx_wdt_enable(struct max63xx_timeout *entry)
 
         /* check for a edge triggered startup */
         if (entry->tdelay == 0)
-                max63xx_wdt_ping();
+                max63xx_wdt_ping(wdd);
+        return 0;
 }
 
-static void max63xx_wdt_disable(void)
+static int max63xx_wdt_stop(struct watchdog_device *wdd)
 {
         u8 val;
 
@@ -164,113 +154,29 @@ static void max63xx_wdt_disable(void)
         __raw_writeb(val, wdt_base);
 
         spin_unlock(&io_lock);
-
-        clear_bit(WDT_RUNNING, &wdt_status);
-}
-
-static int max63xx_wdt_open(struct inode *inode, struct file *file)
-{
-        if (test_and_set_bit(WDT_IN_USE, &wdt_status))
-                return -EBUSY;
-
-        max63xx_wdt_enable(current_timeout);
-        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
-        return nonseekable_open(inode, file);
-}
-
-static ssize_t max63xx_wdt_write(struct file *file, const char *data,
-                                 size_t len, loff_t *ppos)
-{
-        if (len) {
-                if (!nowayout) {
-                        size_t i;
-
-                        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-                        for (i = 0; i != len; i++) {
-                                char c;
-
-                                if (get_user(c, data + i))
-                                        return -EFAULT;
-
-                                if (c == 'V')
-                                        set_bit(WDT_OK_TO_CLOSE, &wdt_status);
-                        }
-                }
-
-                max63xx_wdt_ping();
-        }
-
-        return len;
+        return 0;
 }
 
-static const struct watchdog_info ident = {
-        .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+static const struct watchdog_info max63xx_wdt_info = {
+        .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
         .identity = "max63xx Watchdog",
 };
 
-static long max63xx_wdt_ioctl(struct file *file, unsigned int cmd,
-                              unsigned long arg)
-{
-        int ret = -ENOTTY;
-
-        switch (cmd) {
-        case WDIOC_GETSUPPORT:
-                ret = copy_to_user((struct watchdog_info *)arg, &ident,
-                                   sizeof(ident)) ? -EFAULT : 0;
-                break;
-
-        case WDIOC_GETSTATUS:
-        case WDIOC_GETBOOTSTATUS:
-                ret = put_user(0, (int *)arg);
-                break;
-
-        case WDIOC_KEEPALIVE:
-                max63xx_wdt_ping();
-                ret = 0;
-                break;
-
-        case WDIOC_GETTIMEOUT:
-                ret = put_user(heartbeat, (int *)arg);
-                break;
-        }
-        return ret;
-}
-
-static int max63xx_wdt_release(struct inode *inode, struct file *file)
-{
-        if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
-                max63xx_wdt_disable();
-        else
-                dev_crit(&max63xx_pdev->dev,
-                         "device closed unexpectedly - timer will not stop\n");
-
-        clear_bit(WDT_IN_USE, &wdt_status);
-        clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
-        return 0;
-}
-
-static const struct file_operations max63xx_wdt_fops = {
-        .owner          = THIS_MODULE,
-        .llseek         = no_llseek,
-        .write          = max63xx_wdt_write,
-        .unlocked_ioctl = max63xx_wdt_ioctl,
-        .open           = max63xx_wdt_open,
-        .release        = max63xx_wdt_release,
+static const struct watchdog_ops max63xx_wdt_ops = {
+        .owner = THIS_MODULE,
+        .start = max63xx_wdt_start,
+        .stop = max63xx_wdt_stop,
+        .ping = max63xx_wdt_ping,
 };
 
-static struct miscdevice max63xx_wdt_miscdev = {
-        .minor  = WATCHDOG_MINOR,
-        .name   = "watchdog",
-        .fops   = &max63xx_wdt_fops,
+static struct watchdog_device max63xx_wdt_dev = {
+        .info = &max63xx_wdt_info,
+        .ops = &max63xx_wdt_ops,
 };
 
 static int __devinit max63xx_wdt_probe(struct platform_device *pdev)
 {
-        int ret = 0;
-        int size;
-        struct device *dev = &pdev->dev;
+        struct resource *wdt_mem;
         struct max63xx_timeout *table;
 
         table = (struct max63xx_timeout *)pdev->id_entry->driver_data;
@@ -278,68 +184,34 @@ static int __devinit max63xx_wdt_probe(struct platform_device *pdev)
         if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
                 heartbeat = DEFAULT_HEARTBEAT;
 
-        dev_info(dev, "requesting %ds heartbeat\n", heartbeat);
+        dev_info(&pdev->dev, "requesting %ds heartbeat\n", heartbeat);
         current_timeout = max63xx_select_timeout(table, heartbeat);
 
         if (!current_timeout) {
-                dev_err(dev, "unable to satisfy heartbeat request\n");
+                dev_err(&pdev->dev, "unable to satisfy heartbeat request\n");
                 return -EINVAL;
         }
 
-        dev_info(dev, "using %ds heartbeat with %ds initial delay\n",
+        dev_info(&pdev->dev, "using %ds heartbeat with %ds initial delay\n",
                  current_timeout->twd, current_timeout->tdelay);
 
         heartbeat = current_timeout->twd;
 
-        max63xx_pdev = pdev;
-
         wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-        if (wdt_mem == NULL) {
-                dev_err(dev, "failed to get memory region resource\n");
-                return -ENOENT;
-        }
+        wdt_base = devm_request_and_ioremap(&pdev->dev, wdt_mem);
+        if (!wdt_base)
+                return -ENOMEM;
 
-        size = resource_size(wdt_mem);
-        if (!request_mem_region(wdt_mem->start, size, pdev->name)) {
-                dev_err(dev, "failed to get memory region\n");
-                return -ENOENT;
-        }
-
-        wdt_base = ioremap(wdt_mem->start, size);
-        if (!wdt_base) {
-                dev_err(dev, "failed to map memory region\n");
-                ret = -ENOMEM;
-                goto out_request;
-        }
+        max63xx_wdt_dev.timeout = heartbeat;
+        watchdog_set_nowayout(&max63xx_wdt_dev, nowayout);
+        watchdog_set_drvdata(&max63xx_wdt_dev, current_timeout);
 
-        ret = misc_register(&max63xx_wdt_miscdev);
-        if (ret < 0) {
-                dev_err(dev, "cannot register misc device\n");
-                goto out_unmap;
-        }
-
-        return 0;
-
-out_unmap:
-        iounmap(wdt_base);
-out_request:
-        release_mem_region(wdt_mem->start, size);
-        wdt_mem = NULL;
-
-        return ret;
+        return watchdog_register_device(&max63xx_wdt_dev);
 }
 
 static int __devexit max63xx_wdt_remove(struct platform_device *pdev)
 {
-        misc_deregister(&max63xx_wdt_miscdev);
-        if (wdt_mem) {
-                release_mem_region(wdt_mem->start, resource_size(wdt_mem));
-                wdt_mem = NULL;
-        }
-
-        if (wdt_base)
-                iounmap(wdt_base);
-
+        watchdog_unregister_device(&max63xx_wdt_dev);
         return 0;
 }