watchdog: imx2_wdt: convert to watchdog core api
authorAnatolij Gustschin <agust@denx.de>
Fri, 11 Apr 2014 06:57:14 +0000 (08:57 +0200)
committerWim Van Sebroeck <wim@iguana.be>
Tue, 10 Jun 2014 19:42:59 +0000 (21:42 +0200)
Convert the imx2_wdt driver to the new watchdog core api.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/Kconfig
drivers/watchdog/imx2_wdt.c

index 65ef91e3e497f4b543fa9964f638fc1fde970bb4..9360c5525fa994a9bb1e249c5ada03ee6ffefaa4 100644 (file)
@@ -379,6 +379,7 @@ config IMX2_WDT
        tristate "IMX2+ Watchdog"
        depends on ARCH_MXC
        select REGMAP_MMIO
+       select WATCHDOG_CORE
        help
          This is the driver for the hardware watchdog
          on the Freescale IMX2 and later processors.
index 76fa724930ca562fd5e35dfef7c4bfe2fbfbdb7d..9d4874f09948aa2110fc207730f57d0fe1772fbd 100644 (file)
  */
 
 #include <linux/clk.h>
-#include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
-#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/timer.h>
-#include <linux/uaccess.h>
 #include <linux/watchdog.h>
 
 #define DRIVER_NAME "imx2-wdt"
 
 #define WDOG_SEC_TO_COUNT(s)   ((s * 2 - 1) << 8)
 
-#define IMX2_WDT_STATUS_OPEN   0
-#define IMX2_WDT_STATUS_STARTED        1
-#define IMX2_WDT_EXPECT_CLOSE  2
-
-static struct {
+struct imx2_wdt_device {
        struct clk *clk;
        struct regmap *regmap;
-       unsigned timeout;
-       unsigned long status;
        struct timer_list timer;        /* Pings the watchdog when closed */
-} imx2_wdt;
-
-static struct miscdevice imx2_wdt_miscdev;
+       struct watchdog_device wdog;
+};
 
 static bool nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, bool, 0);
@@ -86,11 +76,12 @@ static const struct watchdog_info imx2_wdt_info = {
        .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 };
 
-static inline void imx2_wdt_setup(void)
+static inline void imx2_wdt_setup(struct watchdog_device *wdog)
 {
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
        u32 val;
 
-       regmap_read(imx2_wdt.regmap, IMX2_WDT_WCR, &val);
+       regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
 
        /* Suspend timer in low power mode, write once-only */
        val |= IMX2_WDT_WCR_WDZST;
@@ -101,157 +92,93 @@ static inline void imx2_wdt_setup(void)
        /* Keep Watchdog Disabled */
        val &= ~IMX2_WDT_WCR_WDE;
        /* Set the watchdog's Time-Out value */
-       val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);
+       val |= WDOG_SEC_TO_COUNT(wdog->timeout);
 
-       regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);
+       regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
 
        /* enable the watchdog */
        val |= IMX2_WDT_WCR_WDE;
-       regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);
+       regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
 }
 
-static inline void imx2_wdt_ping(void)
+static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev)
 {
-       regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
-       regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
-}
+       u32 val;
 
-static void imx2_wdt_timer_ping(unsigned long arg)
-{
-       /* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */
-       imx2_wdt_ping();
-       mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2);
+       regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
+
+       return val & IMX2_WDT_WCR_WDE;
 }
 
-static void imx2_wdt_start(void)
+static int imx2_wdt_ping(struct watchdog_device *wdog)
 {
-       if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
-               /* at our first start we enable clock and do initialisations */
-               clk_prepare_enable(imx2_wdt.clk);
-
-               imx2_wdt_setup();
-       } else  /* delete the timer that pings the watchdog after close */
-               del_timer_sync(&imx2_wdt.timer);
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
 
-       /* Watchdog is enabled - time to reload the timeout value */
-       imx2_wdt_ping();
+       regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
+       regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
+       return 0;
 }
 
-static void imx2_wdt_stop(void)
+static void imx2_wdt_timer_ping(unsigned long arg)
 {
-       /* we don't need a clk_disable, it cannot be disabled once started.
-        * We use a timer to ping the watchdog while /dev/watchdog is closed */
-       imx2_wdt_timer_ping(0);
+       struct watchdog_device *wdog = (struct watchdog_device *)arg;
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+       /* ping it every wdog->timeout / 2 seconds to prevent reboot */
+       imx2_wdt_ping(wdog);
+       mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2);
 }
 
-static void imx2_wdt_set_timeout(int new_timeout)
+static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
+                               unsigned int new_timeout)
 {
-       regmap_update_bits(imx2_wdt.regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+       regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
                           WDOG_SEC_TO_COUNT(new_timeout));
+       return 0;
 }
 
-static int imx2_wdt_open(struct inode *inode, struct file *file)
+static int imx2_wdt_start(struct watchdog_device *wdog)
 {
-       if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
-               return -EBUSY;
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
 
-       imx2_wdt_start();
-       return nonseekable_open(inode, file);
+       if (imx2_wdt_is_running(wdev)) {
+               /* delete the timer that pings the watchdog after close */
+               del_timer_sync(&wdev->timer);
+               imx2_wdt_set_timeout(wdog, wdog->timeout);
+       } else
+               imx2_wdt_setup(wdog);
+
+       return imx2_wdt_ping(wdog);
 }
 
-static int imx2_wdt_close(struct inode *inode, struct file *file)
+static int imx2_wdt_stop(struct watchdog_device *wdog)
 {
-       if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout)
-               imx2_wdt_stop();
-       else {
-               dev_crit(imx2_wdt_miscdev.parent,
-                       "Unexpected close: Expect reboot!\n");
-               imx2_wdt_ping();
-       }
-
-       clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
-       clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status);
+       /*
+        * We don't need a clk_disable, it cannot be disabled once started.
+        * We use a timer to ping the watchdog while /dev/watchdog is closed
+        */
+       imx2_wdt_timer_ping((unsigned long)wdog);
        return 0;
 }
 
-static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
-                                                       unsigned long arg)
+static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog)
 {
-       void __user *argp = (void __user *)arg;
-       int __user *p = argp;
-       int new_value;
-       u32 val;
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
 
-       switch (cmd) {
-       case WDIOC_GETSUPPORT:
-               return copy_to_user(argp, &imx2_wdt_info,
-                       sizeof(struct watchdog_info)) ? -EFAULT : 0;
-
-       case WDIOC_GETSTATUS:
-               return put_user(0, p);
-
-       case WDIOC_GETBOOTSTATUS:
-               regmap_read(imx2_wdt.regmap, IMX2_WDT_WRSR, &val);
-               new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
-               return put_user(new_value, p);
-
-       case WDIOC_KEEPALIVE:
-               imx2_wdt_ping();
-               return 0;
-
-       case WDIOC_SETTIMEOUT:
-               if (get_user(new_value, p))
-                       return -EFAULT;
-               if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME))
-                       return -EINVAL;
-               imx2_wdt_set_timeout(new_value);
-               imx2_wdt.timeout = new_value;
-               imx2_wdt_ping();
-
-               /* Fallthrough to return current value */
-       case WDIOC_GETTIMEOUT:
-               return put_user(imx2_wdt.timeout, p);
-
-       default:
-               return -ENOTTY;
+       if (imx2_wdt_is_running(wdev)) {
+               imx2_wdt_set_timeout(wdog, wdog->timeout);
+               imx2_wdt_timer_ping((unsigned long)wdog);
        }
 }
 
-static ssize_t imx2_wdt_write(struct file *file, const char __user *data,
-                                               size_t len, loff_t *ppos)
-{
-       size_t i;
-       char c;
-
-       if (len == 0)   /* Can we see this even ? */
-               return 0;
-
-       clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
-       /* scan to see whether or not we got the magic character */
-       for (i = 0; i != len; i++) {
-               if (get_user(c, data + i))
-                       return -EFAULT;
-               if (c == 'V')
-                       set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
-       }
-
-       imx2_wdt_ping();
-       return len;
-}
-
-static const struct file_operations imx2_wdt_fops = {
+static struct watchdog_ops imx2_wdt_ops = {
        .owner = THIS_MODULE,
-       .llseek = no_llseek,
-       .unlocked_ioctl = imx2_wdt_ioctl,
-       .open = imx2_wdt_open,
-       .release = imx2_wdt_close,
-       .write = imx2_wdt_write,
-};
-
-static struct miscdevice imx2_wdt_miscdev = {
-       .minor = WATCHDOG_MINOR,
-       .name = "watchdog",
-       .fops = &imx2_wdt_fops,
+       .start = imx2_wdt_start,
+       .stop = imx2_wdt_stop,
+       .ping = imx2_wdt_ping,
+       .set_timeout = imx2_wdt_set_timeout,
 };
 
 static struct regmap_config imx2_wdt_regmap_config = {
@@ -263,76 +190,101 @@ static struct regmap_config imx2_wdt_regmap_config = {
 
 static int __init imx2_wdt_probe(struct platform_device *pdev)
 {
+       struct imx2_wdt_device *wdev;
+       struct watchdog_device *wdog;
        struct resource *res;
        void __iomem *base;
        int ret;
+       u32 val;
+
+       wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
+       if (!wdev)
+               return -ENOMEM;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(base))
                return PTR_ERR(base);
 
-       imx2_wdt.regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
-                                                   &imx2_wdt_regmap_config);
-       if (IS_ERR(imx2_wdt.regmap)) {
+       wdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
+                                                &imx2_wdt_regmap_config);
+       if (IS_ERR(wdev->regmap)) {
                dev_err(&pdev->dev, "regmap init failed\n");
-               return PTR_ERR(imx2_wdt.regmap);
+               return PTR_ERR(wdev->regmap);
        }
 
-       imx2_wdt.clk = devm_clk_get(&pdev->dev, NULL);
-       if (IS_ERR(imx2_wdt.clk)) {
+       wdev->clk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(wdev->clk)) {
                dev_err(&pdev->dev, "can't get Watchdog clock\n");
-               return PTR_ERR(imx2_wdt.clk);
+               return PTR_ERR(wdev->clk);
        }
 
-       imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
-       if (imx2_wdt.timeout != timeout)
-               dev_warn(&pdev->dev, "Initial timeout out of range! "
-                       "Clamped from %u to %u\n", timeout, imx2_wdt.timeout);
+       wdog                    = &wdev->wdog;
+       wdog->info              = &imx2_wdt_info;
+       wdog->ops               = &imx2_wdt_ops;
+       wdog->min_timeout       = 1;
+       wdog->max_timeout       = IMX2_WDT_MAX_TIME;
 
-       setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0);
+       clk_prepare_enable(wdev->clk);
 
-       imx2_wdt_miscdev.parent = &pdev->dev;
-       ret = misc_register(&imx2_wdt_miscdev);
-       if (ret)
-               goto fail;
+       regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);
+       wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
 
-       dev_info(&pdev->dev,
-               "IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n",
-                                               imx2_wdt.timeout, nowayout);
-       return 0;
+       wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
+       if (wdog->timeout != timeout)
+               dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n",
+                        timeout, wdog->timeout);
+
+       platform_set_drvdata(pdev, wdog);
+       watchdog_set_drvdata(wdog, wdev);
+       watchdog_set_nowayout(wdog, nowayout);
+       watchdog_init_timeout(wdog, timeout, &pdev->dev);
+
+       setup_timer(&wdev->timer, imx2_wdt_timer_ping, (unsigned long)wdog);
 
-fail:
-       imx2_wdt_miscdev.parent = NULL;
-       return ret;
+       imx2_wdt_ping_if_active(wdog);
+
+       ret = watchdog_register_device(wdog);
+       if (ret) {
+               dev_err(&pdev->dev, "cannot register watchdog device\n");
+               return ret;
+       }
+
+       dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n",
+                wdog->timeout, nowayout);
+
+       return 0;
 }
 
 static int __exit imx2_wdt_remove(struct platform_device *pdev)
 {
-       misc_deregister(&imx2_wdt_miscdev);
+       struct watchdog_device *wdog = platform_get_drvdata(pdev);
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
 
-       if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
-               del_timer_sync(&imx2_wdt.timer);
+       watchdog_unregister_device(wdog);
 
-               dev_crit(imx2_wdt_miscdev.parent,
-                       "Device removed: Expect reboot!\n");
+       if (imx2_wdt_is_running(wdev)) {
+               del_timer_sync(&wdev->timer);
+               imx2_wdt_ping(wdog);
+               dev_crit(&pdev->dev, "Device removed: Expect reboot!\n");
        }
-
-       imx2_wdt_miscdev.parent = NULL;
        return 0;
 }
 
 static void imx2_wdt_shutdown(struct platform_device *pdev)
 {
-       if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
-               /* we are running, we need to delete the timer but will give
-                * max timeout before reboot will take place */
-               del_timer_sync(&imx2_wdt.timer);
-               imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME);
-               imx2_wdt_ping();
-
-               dev_crit(imx2_wdt_miscdev.parent,
-                       "Device shutdown: Expect reboot!\n");
+       struct watchdog_device *wdog = platform_get_drvdata(pdev);
+       struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
+
+       if (imx2_wdt_is_running(wdev)) {
+               /*
+                * We are running, we need to delete the timer but will
+                * give max timeout before reboot will take place
+                */
+               del_timer_sync(&wdev->timer);
+               imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
+               imx2_wdt_ping(wdog);
+               dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n");
        }
 }