cgroup: superblock can't be released with active dentries
[firefly-linux-kernel-4.4.55.git] / drivers / watchdog / ep93xx_wdt.c
index 09cd888db6197238200b270f24a9bc00b257cbd5..77050037597a08603c1cbbe6d0e6cf9acb32efee 100644 (file)
@@ -8,6 +8,9 @@
  * Authors: Ray Lehtiniemi <rayl@mail.com>,
  *     Alessandro Zummo <a.zummo@towertech.it>
  *
+ * Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
+ *     Convert to a platform device and use the watchdog framework API
+ *
  * This file is licensed under the terms of the GNU General Public
  * License version 2. This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
 
 #include <linux/platform_device.h>
 #include <linux/module.h>
-#include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/watchdog.h>
 #include <linux/timer.h>
-#include <linux/uaccess.h>
 #include <linux/io.h>
 
-#define WDT_VERSION    "0.3"
-#define PFX            "ep93xx_wdt: "
+#define WDT_VERSION    "0.4"
 
 /* default timeout (secs) */
 #define WDT_TIMEOUT 30
 
-static int nowayout = WATCHDOG_NOWAYOUT;
-static int timeout = WDT_TIMEOUT;
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
+
+static unsigned int timeout = WDT_TIMEOUT;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+       "Watchdog timeout in seconds. (1<=timeout<=3600, default="
+                               __MODULE_STRING(WDT_TIMEOUT) ")");
 
 static void __iomem *mmio_base;
 static struct timer_list timer;
 static unsigned long next_heartbeat;
-static unsigned long wdt_status;
-static unsigned long boot_status;
-
-#define WDT_IN_USE             0
-#define WDT_OK_TO_CLOSE                1
 
 #define EP93XX_WATCHDOG                0x00
 #define EP93XX_WDSTATUS                0x04
 
-/* reset the wdt every ~200ms */
+/* reset the wdt every ~200ms - the heartbeat of the device is 0.250 seconds*/
 #define WDT_INTERVAL (HZ/5)
 
-static void wdt_enable(void)
+static void ep93xx_wdt_timer_ping(unsigned long data)
 {
-       writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);
-}
-
-static void wdt_disable(void)
-{
-       writel(0xaa55, mmio_base + EP93XX_WATCHDOG);
-}
+       if (time_before(jiffies, next_heartbeat))
+               writel(0x5555, mmio_base + EP93XX_WATCHDOG);
 
-static inline void wdt_ping(void)
-{
-       writel(0x5555, mmio_base + EP93XX_WATCHDOG);
+       /* Re-set the timer interval */
+       mod_timer(&timer, jiffies + WDT_INTERVAL);
 }
 
-static void wdt_startup(void)
+static int ep93xx_wdt_start(struct watchdog_device *wdd)
 {
        next_heartbeat = jiffies + (timeout * HZ);
 
-       wdt_enable();
+       writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);
        mod_timer(&timer, jiffies + WDT_INTERVAL);
+
+       return 0;
 }
 
-static void wdt_shutdown(void)
+static int ep93xx_wdt_stop(struct watchdog_device *wdd)
 {
        del_timer_sync(&timer);
-       wdt_disable();
+       writel(0xaa55, mmio_base + EP93XX_WATCHDOG);
+
+       return 0;
 }
 
-static void wdt_keepalive(void)
+static int ep93xx_wdt_keepalive(struct watchdog_device *wdd)
 {
        /* user land ping */
        next_heartbeat = jiffies + (timeout * HZ);
-}
-
-static int ep93xx_wdt_open(struct inode *inode, struct file *file)
-{
-       if (test_and_set_bit(WDT_IN_USE, &wdt_status))
-               return -EBUSY;
-
-       clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-
-       wdt_startup();
-
-       return nonseekable_open(inode, file);
-}
-
-static ssize_t
-ep93xx_wdt_write(struct file *file, const char __user *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);
-                               else
-                                       clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
-                       }
-               }
-               wdt_keepalive();
-       }
 
-       return len;
+       return 0;
 }
 
-static const struct watchdog_info ident = {
-       .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE,
-       .identity = "EP93xx Watchdog",
+static const struct watchdog_info ep93xx_wdt_ident = {
+       .options        = WDIOF_CARDRESET |
+                         WDIOF_MAGICCLOSE |
+                         WDIOF_KEEPALIVEPING,
+       .identity       = "EP93xx Watchdog",
 };
 
-static long ep93xx_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 __user *)arg, &ident,
-                               sizeof(ident)) ? -EFAULT : 0;
-               break;
-
-       case WDIOC_GETSTATUS:
-               ret = put_user(0, (int __user *)arg);
-               break;
-
-       case WDIOC_GETBOOTSTATUS:
-               ret = put_user(boot_status, (int __user *)arg);
-               break;
-
-       case WDIOC_KEEPALIVE:
-               wdt_keepalive();
-               ret = 0;
-               break;
-
-       case WDIOC_GETTIMEOUT:
-               /* actually, it is 0.250 seconds.... */
-               ret = put_user(1, (int __user *)arg);
-               break;
-       }
-       return ret;
-}
-
-static int ep93xx_wdt_release(struct inode *inode, struct file *file)
-{
-       if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
-               wdt_shutdown();
-       else
-               printk(KERN_CRIT PFX
-                       "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 ep93xx_wdt_fops = {
+static struct watchdog_ops ep93xx_wdt_ops = {
        .owner          = THIS_MODULE,
-       .write          = ep93xx_wdt_write,
-       .unlocked_ioctl = ep93xx_wdt_ioctl,
-       .open           = ep93xx_wdt_open,
-       .release        = ep93xx_wdt_release,
-       .llseek         = no_llseek,
+       .start          = ep93xx_wdt_start,
+       .stop           = ep93xx_wdt_stop,
+       .ping           = ep93xx_wdt_keepalive,
 };
 
-static struct miscdevice ep93xx_wdt_miscdev = {
-       .minor          = WATCHDOG_MINOR,
-       .name           = "watchdog",
-       .fops           = &ep93xx_wdt_fops,
+static struct watchdog_device ep93xx_wdt_wdd = {
+       .info           = &ep93xx_wdt_ident,
+       .ops            = &ep93xx_wdt_ops,
 };
 
-static void ep93xx_timer_ping(unsigned long data)
-{
-       if (time_before(jiffies, next_heartbeat))
-               wdt_ping();
-
-       /* Re-set the timer interval */
-       mod_timer(&timer, jiffies + WDT_INTERVAL);
-}
-
 static int __devinit ep93xx_wdt_probe(struct platform_device *pdev)
 {
        struct resource *res;
@@ -224,30 +130,35 @@ static int __devinit ep93xx_wdt_probe(struct platform_device *pdev)
        if (!mmio_base)
                return -ENXIO;
 
-       err = misc_register(&ep93xx_wdt_miscdev);
-
-       val = readl(mmio_base + EP93XX_WATCHDOG);
-       boot_status = val & 0x01 ? 1 : 0;
-
-       printk(KERN_INFO PFX "EP93XX watchdog, driver version "
-               WDT_VERSION "%s\n",
-               (val & 0x08) ? " (nCS1 disable detected)" : "");
-
        if (timeout < 1 || timeout > 3600) {
                timeout = WDT_TIMEOUT;
-               printk(KERN_INFO PFX
+               dev_warn(&pdev->dev,
                        "timeout value must be 1<=x<=3600, using %d\n",
                        timeout);
        }
 
-       setup_timer(&timer, ep93xx_timer_ping, 1);
-       return err;
+       val = readl(mmio_base + EP93XX_WATCHDOG);
+       ep93xx_wdt_wdd.bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
+       ep93xx_wdt_wdd.timeout = timeout;
+
+       watchdog_set_nowayout(&ep93xx_wdt_wdd, nowayout);
+
+       setup_timer(&timer, ep93xx_wdt_timer_ping, 1);
+
+       err = watchdog_register_device(&ep93xx_wdt_wdd);
+       if (err)
+               return err;
+
+       dev_info(&pdev->dev,
+               "EP93XX watchdog, driver version " WDT_VERSION "%s\n",
+               (val & 0x08) ? " (nCS1 disable detected)" : "");
+
+       return 0;
 }
 
 static int __devexit ep93xx_wdt_remove(struct platform_device *pdev)
 {
-       wdt_shutdown();
-       misc_deregister(&ep93xx_wdt_miscdev);
+       watchdog_unregister_device(&ep93xx_wdt_wdd);
        return 0;
 }
 
@@ -262,16 +173,9 @@ static struct platform_driver ep93xx_wdt_driver = {
 
 module_platform_driver(ep93xx_wdt_driver);
 
-module_param(nowayout, int, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
-
-module_param(timeout, int, 0);
-MODULE_PARM_DESC(timeout,
-       "Watchdog timeout in seconds. (1<=timeout<=3600, default="
-                               __MODULE_STRING(WDT_TIMEOUT) ")");
-
 MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>,"
-               "Alessandro Zummo <a.zummo@towertech.it>");
+               "Alessandro Zummo <a.zummo@towertech.it>,"
+               "H Hartley Sweeten <hsweeten@visionengravers.com>");
 MODULE_DESCRIPTION("EP93xx Watchdog");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(WDT_VERSION);