watchdog: Convert twl4030_wdt to watchdog core

Convert the twl4030_wdt watchdog driver to watchdog core.

While at there use devm_kzalloc and set the default timeout in order to be
able test this driver with a simple shell script.

Signed-off-by: Jarkko Nikula <jarkko.nikula@jollamobile.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

2 files changed, 35 insertions, 149 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index ad1bb9382a96..ae5af82ac31a 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -300,6 +300,7 @@ config COH901327_WATCHDOG
 config TWL4030_WATCHDOG
         tristate "TWL4030 Watchdog"
         depends on TWL4030_CORE
+        select WATCHDOG_CORE
         help
           Support for TI TWL4030 watchdog.  Say 'Y' here to enable the
           watchdog timer support for TWL4030 chips.
diff --git a/drivers/watchdog/twl4030_wdt.c b/drivers/watchdog/twl4030_wdt.c
index 9f54b1da7185..01d63674c94f 100644
--- a/drivers/watchdog/twl4030_wdt.c
+++ b/drivers/watchdog/twl4030_wdt.c
@@ -22,26 +22,12 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/kernel.h>
-#include <linux/fs.h>
 #include <linux/watchdog.h>
 #include <linux/platform_device.h>
-#include <linux/miscdevice.h>
-#include <linux/uaccess.h>
 #include <linux/i2c/twl.h>
 
 #define TWL4030_WATCHDOG_CFG_REG_OFFS   0x3
 
-#define TWL4030_WDT_STATE_OPEN          0x1
-#define TWL4030_WDT_STATE_ACTIVE        0x8
-
-static struct platform_device *twl4030_wdt_dev;
-
-struct twl4030_wdt {
-        struct miscdevice       miscdev;
-        int                     timer_margin;
-        unsigned long           state;
-};
-
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
@@ -53,171 +39,71 @@ static int twl4030_wdt_write(unsigned char val)
                                         TWL4030_WATCHDOG_CFG_REG_OFFS);
 }
 
-static int twl4030_wdt_enable(struct twl4030_wdt *wdt)
+static int twl4030_wdt_start(struct watchdog_device *wdt)
 {
-        return twl4030_wdt_write(wdt->timer_margin + 1);
+        return twl4030_wdt_write(wdt->timeout + 1);
 }
 
-static int twl4030_wdt_disable(struct twl4030_wdt *wdt)
+static int twl4030_wdt_stop(struct watchdog_device *wdt)
 {
         return twl4030_wdt_write(0);
 }
 
-static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout)
-{
-        if (timeout < 0 || timeout > 30) {
-                dev_warn(wdt->miscdev.parent,
-                        "Timeout can only be in the range [0-30] seconds");
-                return -EINVAL;
-        }
-        wdt->timer_margin = timeout;
-        return twl4030_wdt_enable(wdt);
-}
-
-static ssize_t twl4030_wdt_write_fop(struct file *file,
-                const char __user *data, size_t len, loff_t *ppos)
+static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
+                                   unsigned int timeout)
 {
-        struct twl4030_wdt *wdt = file->private_data;
-
-        if (len)
-                twl4030_wdt_enable(wdt);
-
-        return len;
-}
-
-static long twl4030_wdt_ioctl(struct file *file,
-                unsigned int cmd, unsigned long arg)
-{
-        void __user *argp = (void __user *)arg;
-        int __user *p = argp;
-        int new_margin;
-        struct twl4030_wdt *wdt = file->private_data;
-
-        static const struct watchdog_info twl4030_wd_ident = {
-                .identity = "TWL4030 Watchdog",
-                .options = WDIOF_SETTIMEOUT,
-                .firmware_version = 0,
-        };
-
-        switch (cmd) {
-        case WDIOC_GETSUPPORT:
-                return copy_to_user(argp, &twl4030_wd_ident,
-                                sizeof(twl4030_wd_ident)) ? -EFAULT : 0;
-
-        case WDIOC_GETSTATUS:
-        case WDIOC_GETBOOTSTATUS:
-                return put_user(0, p);
-
-        case WDIOC_KEEPALIVE:
-                twl4030_wdt_enable(wdt);
-                break;
-
-        case WDIOC_SETTIMEOUT:
-                if (get_user(new_margin, p))
-                        return -EFAULT;
-                if (twl4030_wdt_set_timeout(wdt, new_margin))
-                        return -EINVAL;
-                return put_user(wdt->timer_margin, p);
-
-        case WDIOC_GETTIMEOUT:
-                return put_user(wdt->timer_margin, p);
-
-        default:
-                return -ENOTTY;
-        }
-
+        wdt->timeout = timeout;
         return 0;
 }
 
-static int twl4030_wdt_open(struct inode *inode, struct file *file)
-{
-        struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev);
-
-        /* /dev/watchdog can only be opened once */
-        if (test_and_set_bit(0, &wdt->state))
-                return -EBUSY;
-
-        wdt->state |= TWL4030_WDT_STATE_ACTIVE;
-        file->private_data = (void *) wdt;
-
-        twl4030_wdt_enable(wdt);
-        return nonseekable_open(inode, file);
-}
-
-static int twl4030_wdt_release(struct inode *inode, struct file *file)
-{
-        struct twl4030_wdt *wdt = file->private_data;
-        if (nowayout) {
-                dev_alert(wdt->miscdev.parent,
-                       "Unexpected close, watchdog still running!\n");
-                twl4030_wdt_enable(wdt);
-        } else {
-                if (twl4030_wdt_disable(wdt))
-                        return -EFAULT;
-                wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
-        }
-
-        clear_bit(0, &wdt->state);
-        return 0;
-}
+static const struct watchdog_info twl4030_wdt_info = {
+        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+        .identity = "TWL4030 Watchdog",
+};
 
-static const struct file_operations twl4030_wdt_fops = {
+static const struct watchdog_ops twl4030_wdt_ops = {
         .owner          = THIS_MODULE,
-        .llseek         = no_llseek,
-        .open           = twl4030_wdt_open,
-        .release        = twl4030_wdt_release,
-        .unlocked_ioctl = twl4030_wdt_ioctl,
-        .write          = twl4030_wdt_write_fop,
+        .start          = twl4030_wdt_start,
+        .stop           = twl4030_wdt_stop,
+        .set_timeout    = twl4030_wdt_set_timeout,
 };
 
 static int twl4030_wdt_probe(struct platform_device *pdev)
 {
         int ret = 0;
-        struct twl4030_wdt *wdt;
+        struct watchdog_device *wdt;
 
-        wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL);
+        wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
         if (!wdt)
                 return -ENOMEM;
 
-        wdt->state              = 0;
-        wdt->timer_margin       = 30;
-        wdt->miscdev.parent     = &pdev->dev;
-        wdt->miscdev.fops       = &twl4030_wdt_fops;
-        wdt->miscdev.minor      = WATCHDOG_MINOR;
-        wdt->miscdev.name       = "watchdog";
+        wdt->info               = &twl4030_wdt_info;
+        wdt->ops                = &twl4030_wdt_ops;
+        wdt->status             = 0;
+        wdt->timeout            = 30;
+        wdt->min_timeout        = 1;
+        wdt->max_timeout        = 30;
 
+        watchdog_set_nowayout(wdt, nowayout);
         platform_set_drvdata(pdev, wdt);
 
-        twl4030_wdt_dev = pdev;
+        twl4030_wdt_stop(wdt);
 
-        twl4030_wdt_disable(wdt);
-
-        ret = misc_register(&wdt->miscdev);
+        ret = watchdog_register_device(wdt);
         if (ret) {
-                dev_err(wdt->miscdev.parent,
-                        "Failed to register misc device\n");
                 platform_set_drvdata(pdev, NULL);
-                kfree(wdt);
-                twl4030_wdt_dev = NULL;
                 return ret;
         }
+
         return 0;
 }
 
 static int twl4030_wdt_remove(struct platform_device *pdev)
 {
-        struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
-
-        if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
-                if (twl4030_wdt_disable(wdt))
-                        return -EFAULT;
-
-        wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
-        misc_deregister(&wdt->miscdev);
+        struct watchdog_device *wdt = platform_get_drvdata(pdev);
 
+        watchdog_unregister_device(wdt);
         platform_set_drvdata(pdev, NULL);
-        kfree(wdt);
-        twl4030_wdt_dev = NULL;
 
         return 0;
 }
@@ -225,18 +111,18 @@ static int twl4030_wdt_remove(struct platform_device *pdev)
 #ifdef CONFIG_PM
 static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
 {
-        struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
-        if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
-                return twl4030_wdt_disable(wdt);
+        struct watchdog_device *wdt = platform_get_drvdata(pdev);
+        if (watchdog_active(wdt))
+                return twl4030_wdt_stop(wdt);
 
         return 0;
 }
 
 static int twl4030_wdt_resume(struct platform_device *pdev)
 {
-        struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
-        if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
-                return twl4030_wdt_enable(wdt);
+        struct watchdog_device *wdt = platform_get_drvdata(pdev);
+        if (watchdog_active(wdt))
+                return twl4030_wdt_start(wdt);
 
         return 0;
 }
@@ -260,6 +146,5 @@ module_platform_driver(twl4030_wdt_driver);
 
 MODULE_AUTHOR("Nokia Corporation");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 MODULE_ALIAS("platform:twl4030_wdt");