watchdog: at91sam9_wdt: Convert to use the watchdog framework

According to Documentation/watchdog/convert_drivers_to_kernel_api.txt,
remove the file_operations struct, miscdevice, and obsolete includes

Since the at91sam watchdog inherent characteristics, add the watchdog
operations: at91wdt_start, at91wdt_stop and at91wdt_ping.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

2 files changed, 43 insertions, 119 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index f3aae8ccb6f0..83ac1f7ac32c 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -125,6 +125,7 @@ config AT91RM9200_WATCHDOG
 config AT91SAM9X_WATCHDOG
         tristate "AT91SAM9X / AT91CAP9 watchdog"
         depends on ARCH_AT91 && !ARCH_AT91RM9200
+        select WATCHDOG_CORE
         help
           Watchdog timer embedded into AT91SAM9X and AT91CAP9 chips. This will
           reboot your system when the timeout is reached.
diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
index feb203f39e1a..8038b20284ce 100644
--- a/drivers/watchdog/at91sam9_wdt.c
+++ b/drivers/watchdog/at91sam9_wdt.c
@@ -18,11 +18,9 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/errno.h>
-#include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
-#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
@@ -68,19 +66,17 @@ module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
         "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
+static struct watchdog_device at91_wdt_dev;
 static void at91_ping(unsigned long data);
 
 static struct {
         void __iomem *base;
         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
-        unsigned long open;
-        char expect_close;
         struct timer_list timer;        /* The timer that pings the watchdog */
 } at91wdt_private;
 
 /* ......................................................................... */
 
-
 /*
  * Reload the watchdog timer.  (ie, pat the watchdog)
  */
@@ -95,39 +91,37 @@ static inline void at91_wdt_reset(void)
 static void at91_ping(unsigned long data)
 {
         if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
-                        (!nowayout && !at91wdt_private.open)) {
+            (!watchdog_active(&at91_wdt_dev))) {
                 at91_wdt_reset();
                 mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
         } else
                 pr_crit("I will reset your machine !\n");
 }
 
-/*
- * Watchdog device is opened, and watchdog starts running.
- */
-static int at91_wdt_open(struct inode *inode, struct file *file)
+static int at91_wdt_ping(struct watchdog_device *wdd)
 {
-        if (test_and_set_bit(0, &at91wdt_private.open))
-                return -EBUSY;
+        /* calculate when the next userspace timeout will be */
+        at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
+        return 0;
+}
 
-        at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
+static int at91_wdt_start(struct watchdog_device *wdd)
+{
+        /* calculate the next userspace timeout and modify the timer */
+        at91_wdt_ping(wdd);
         mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
-
-        return nonseekable_open(inode, file);
+        return 0;
 }
 
-/*
- * Close the watchdog device.
- */
-static int at91_wdt_close(struct inode *inode, struct file *file)
+static int at91_wdt_stop(struct watchdog_device *wdd)
 {
-        clear_bit(0, &at91wdt_private.open);
-
-        /* stop internal ping */
-        if (!at91wdt_private.expect_close)
-                del_timer(&at91wdt_private.timer);
+        /* The watchdog timer hardware can not be stopped... */
+        return 0;
+}
 
-        at91wdt_private.expect_close = 0;
+static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int new_timeout)
+{
+        wdd->timeout = new_timeout;
         return 0;
 }
 
@@ -163,96 +157,27 @@ static int at91_wdt_settimeout(unsigned int timeout)
         return 0;
 }
 
+/* ......................................................................... */
+
 static const struct watchdog_info at91_wdt_info = {
         .identity       = DRV_NAME,
         .options        = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
                                                 WDIOF_MAGICCLOSE,
 };
 
-/*
- * Handle commands from user-space.
- */
-static long at91_wdt_ioctl(struct file *file,
-                unsigned int cmd, unsigned long arg)
-{
-        void __user *argp = (void __user *)arg;
-        int __user *p = argp;
-        int new_value;
-
-        switch (cmd) {
-        case WDIOC_GETSUPPORT:
-                return copy_to_user(argp, &at91_wdt_info,
-                                    sizeof(at91_wdt_info)) ? -EFAULT : 0;
-
-        case WDIOC_GETSTATUS:
-        case WDIOC_GETBOOTSTATUS:
-                return put_user(0, p);
-
-        case WDIOC_KEEPALIVE:
-                at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
-                return 0;
-
-        case WDIOC_SETTIMEOUT:
-                if (get_user(new_value, p))
-                        return -EFAULT;
-
-                heartbeat = new_value;
-                at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
-
-                return put_user(new_value, p);  /* return current value */
-
-        case WDIOC_GETTIMEOUT:
-                return put_user(heartbeat, p);
-        }
-        return -ENOTTY;
-}
-
-/*
- * Pat the watchdog whenever device is written to.
- */
-static ssize_t at91_wdt_write(struct file *file, const char *data, size_t len,
-                                                                loff_t *ppos)
-{
-        if (!len)
-                return 0;
-
-        /* Scan for magic character */
-        if (!nowayout) {
-                size_t i;
-
-                at91wdt_private.expect_close = 0;
-
-                for (i = 0; i < len; i++) {
-                        char c;
-                        if (get_user(c, data + i))
-                                return -EFAULT;
-                        if (c == 'V') {
-                                at91wdt_private.expect_close = 42;
-                                break;
-                        }
-                }
-        }
-
-        at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
-
-        return len;
-}
-
-/* ......................................................................... */
-
-static const struct file_operations at91wdt_fops = {
-        .owner                  = THIS_MODULE,
-        .llseek                 = no_llseek,
-        .unlocked_ioctl = at91_wdt_ioctl,
-        .open                   = at91_wdt_open,
-        .release                = at91_wdt_close,
-        .write                  = at91_wdt_write,
+static const struct watchdog_ops at91_wdt_ops = {
+        .owner =        THIS_MODULE,
+        .start =        at91_wdt_start,
+        .stop =         at91_wdt_stop,
+        .ping =         at91_wdt_ping,
+        .set_timeout =  at91_wdt_set_timeout,
 };
 
-static struct miscdevice at91wdt_miscdev = {
-        .minor          = WATCHDOG_MINOR,
-        .name           = "watchdog",
-        .fops           = &at91wdt_fops,
+static struct watchdog_device at91_wdt_dev = {
+        .info =         &at91_wdt_info,
+        .ops =          &at91_wdt_ops,
+        .min_timeout =  1,
+        .max_timeout =  0xFFFF,
 };
 
 static int __init at91wdt_probe(struct platform_device *pdev)
@@ -260,10 +185,6 @@ static int __init at91wdt_probe(struct platform_device *pdev)
         struct resource *r;
         int res;
 
-        if (at91wdt_miscdev.parent)
-                return -EBUSY;
-        at91wdt_miscdev.parent = &pdev->dev;
-
         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         if (!r)
                 return -ENODEV;
@@ -273,16 +194,20 @@ static int __init at91wdt_probe(struct platform_device *pdev)
                 return -ENOMEM;
         }
 
+        at91_wdt_dev.timeout = heartbeat;
+        at91_wdt_dev.parent = &pdev->dev;
+        watchdog_set_nowayout(&at91_wdt_dev, nowayout);
+
         /* Set watchdog */
         res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
         if (res)
                 return res;
 
-        res = misc_register(&at91wdt_miscdev);
+        res = watchdog_register_device(&at91_wdt_dev);
         if (res)
                 return res;
 
-        at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
+        at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout * HZ;
         setup_timer(&at91wdt_private.timer, at91_ping, 0);
         mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
 
@@ -294,13 +219,12 @@ static int __init at91wdt_probe(struct platform_device *pdev)
 
 static int __exit at91wdt_remove(struct platform_device *pdev)
 {
-        int res;
+        watchdog_unregister_device(&at91_wdt_dev);
 
-        res = misc_deregister(&at91wdt_miscdev);
-        if (!res)
-                at91wdt_miscdev.parent = NULL;
+        pr_warn("I quit now, hardware will probably reboot!\n");
+        del_timer(&at91wdt_private.timer);
 
-        return res;
+        return 0;
 }
 
 #if defined(CONFIG_OF)
@@ -326,4 +250,3 @@ module_platform_driver_probe(at91wdt_driver, at91wdt_probe);
 MODULE_AUTHOR("Renaud CERRATO <r.cerrato@til-technologies.fr>");
 MODULE_DESCRIPTION("Watchdog driver for Atmel AT91SAM9x processors");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);