AR7 watchdog supports magic close
[openwrt/svn-archive/archive.git] / target / linux / ar7 / files / drivers / char / watchdog / ar7_wdt.c
index 04c2e2e94b8d9a2ec6fbeb6745156c30eeaab620..97cd8105a977c537b429326822155a33d0663f8f 100644 (file)
@@ -1,7 +1,7 @@
 /*
- * linux/drivers/char/ar7_wdt.c
- * 
- * Copyright (C) 2007 OpenWrt.org
+ * drivers/watchdog/ar7_wdt.c
+ *
+ * Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>
  * Copyright (c) 2005 Enrik Berkhan <Enrik.Berkhan@akk.org>
  *
  * Some code taken from:
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
- * 
+ *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
@@ -55,11 +55,14 @@ static int nowayout = WATCHDOG_NOWAYOUT;
 module_param(nowayout, int, 0);
 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
 
+#define READ_REG(x) readl((void __iomem *)&(x))
+#define WRITE_REG(x, v) writel((v), (void __iomem *)&(x))
+
 struct ar7_wdt {
        u32 kick_lock;
        u32 kick;
        u32 change_lock;
-       u32 change ;
+       u32 change;
        u32 disable_lock;
        u32 disable;
        u32 prescale_lock;
@@ -93,11 +96,11 @@ static void ar7_wdt_get_regs(void)
 
 static void ar7_wdt_kick(u32 value)
 {
-       ar7_wdt->kick_lock = 0x5555;
-       if ((ar7_wdt->kick_lock & 3) == 1) {
-               ar7_wdt->kick_lock = 0xaaaa;
-               if ((ar7_wdt->kick_lock & 3) == 3) {
-                       ar7_wdt->kick = value;
+       WRITE_REG(ar7_wdt->kick_lock, 0x5555);
+       if ((READ_REG(ar7_wdt->kick_lock) & 3) == 1) {
+               WRITE_REG(ar7_wdt->kick_lock, 0xaaaa);
+               if ((READ_REG(ar7_wdt->kick_lock) & 3) == 3) {
+                       WRITE_REG(ar7_wdt->kick, value);
                        return;
                }
        }
@@ -106,11 +109,11 @@ static void ar7_wdt_kick(u32 value)
 
 static void ar7_wdt_prescale(u32 value)
 {
-       ar7_wdt->prescale_lock = 0x5a5a;
-       if ((ar7_wdt->prescale_lock & 3) == 1) {
-               ar7_wdt->prescale_lock = 0xa5a5;
-               if ((ar7_wdt->prescale_lock & 3) == 3) {
-                       ar7_wdt->prescale = value;
+       WRITE_REG(ar7_wdt->prescale_lock, 0x5a5a);
+       if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 1) {
+               WRITE_REG(ar7_wdt->prescale_lock, 0xa5a5);
+               if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 3) {
+                       WRITE_REG(ar7_wdt->prescale, value);
                        return;
                }
        }
@@ -119,11 +122,11 @@ static void ar7_wdt_prescale(u32 value)
 
 static void ar7_wdt_change(u32 value)
 {
-       ar7_wdt->change_lock = 0x6666;
-       if ((ar7_wdt->change_lock & 3) == 1) {
-               ar7_wdt->change_lock = 0xbbbb;
-               if ((ar7_wdt->change_lock & 3) == 3) {
-                       ar7_wdt->change = value;
+       WRITE_REG(ar7_wdt->change_lock, 0x6666);
+       if ((READ_REG(ar7_wdt->change_lock) & 3) == 1) {
+               WRITE_REG(ar7_wdt->change_lock, 0xbbbb);
+               if ((READ_REG(ar7_wdt->change_lock) & 3) == 3) {
+                       WRITE_REG(ar7_wdt->change, value);
                        return;
                }
        }
@@ -132,13 +135,13 @@ static void ar7_wdt_change(u32 value)
 
 static void ar7_wdt_disable(u32 value)
 {
-       ar7_wdt->disable_lock = 0x7777;
-       if ((ar7_wdt->disable_lock & 3) == 1) {
-               ar7_wdt->disable_lock = 0xcccc;
-               if ((ar7_wdt->disable_lock & 3) == 2) {
-                       ar7_wdt->disable_lock = 0xdddd;
-                       if ((ar7_wdt->disable_lock & 3) == 3) {
-                               ar7_wdt->disable = value;
+       WRITE_REG(ar7_wdt->disable_lock, 0x7777);
+       if ((READ_REG(ar7_wdt->disable_lock) & 3) == 1) {
+               WRITE_REG(ar7_wdt->disable_lock, 0xcccc);
+               if ((READ_REG(ar7_wdt->disable_lock) & 3) == 2) {
+                       WRITE_REG(ar7_wdt->disable_lock, 0xdddd);
+                       if ((READ_REG(ar7_wdt->disable_lock) & 3) == 3) {
+                               WRITE_REG(ar7_wdt->disable, value);
                                return;
                        }
                }
@@ -181,18 +184,18 @@ static int ar7_wdt_open(struct inode *inode, struct file *file)
        ar7_wdt_enable_wdt();
        expect_close = 0;
 
-       return 0;
+       return nonseekable_open(inode, file);
 }
 
 static int ar7_wdt_release(struct inode *inode, struct file *file)
 {
-       if (!expect_close) {
+       if (!expect_close)
                printk(KERN_WARNING DRVNAME
                ": watchdog device closed unexpectedly,"
                "will not disable the watchdog timer\n");
-       } else if (!nowayout) {
+       else if (!nowayout)
                ar7_wdt_disable_wdt();
-       }
+
        up(&open_semaphore);
 
        return 0;
@@ -215,9 +218,6 @@ static struct notifier_block ar7_wdt_notifier = {
 static ssize_t ar7_wdt_write(struct file *file, const char *data,
                             size_t len, loff_t *ppos)
 {
-       if (ppos != &file->f_pos)
-               return -ESPIPE;
-
        /* check for a magic close character */
        if (len) {
                size_t i;
@@ -243,7 +243,7 @@ static int ar7_wdt_ioctl(struct inode *inode, struct file *file,
        static struct watchdog_info ident = {
                .identity = LONGNAME,
                .firmware_version = 1,
-               .options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING),
+               .options = (WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING),
        };
        int new_margin;
 
@@ -280,24 +280,24 @@ static int ar7_wdt_ioctl(struct inode *inode, struct file *file,
 }
 
 static struct file_operations ar7_wdt_fops = {
-       .owner   = THIS_MODULE,
-       .write   = ar7_wdt_write,
-       .ioctl   = ar7_wdt_ioctl,
-       .open    = ar7_wdt_open,
-       .release = ar7_wdt_release,
+       .owner          = THIS_MODULE,
+       .write          = ar7_wdt_write,
+       .ioctl          = ar7_wdt_ioctl,
+       .open           = ar7_wdt_open,
+       .release        = ar7_wdt_release,
 };
 
 static struct miscdevice ar7_wdt_miscdev = {
-       .minor = WATCHDOG_MINOR,
-       .name  = "watchdog",
-       .fops  = &ar7_wdt_fops,
+       .minor          = WATCHDOG_MINOR,
+       .name           = "watchdog",
+       .fops           = &ar7_wdt_fops,
 };
 
 static int __init ar7_wdt_init(void)
 {
        int rc;
 
-    ar7_wdt_get_regs();
+       ar7_wdt_get_regs();
 
        if (!request_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt),
                                                        LONGNAME)) {
@@ -314,23 +314,24 @@ static int __init ar7_wdt_init(void)
 
        sema_init(&open_semaphore, 1);
 
-       rc = misc_register(&ar7_wdt_miscdev);
+       rc = register_reboot_notifier(&ar7_wdt_notifier);
        if (rc) {
-               printk(KERN_ERR DRVNAME ": unable to register misc device\n");
+               printk(KERN_ERR DRVNAME
+                       ": unable to register reboot notifier\n");
                goto out_alloc;
        }
 
-       rc = register_reboot_notifier(&ar7_wdt_notifier);
+       rc = misc_register(&ar7_wdt_miscdev);
        if (rc) {
-               printk(KERN_ERR DRVNAME
-                       ": unable to register reboot notifier\n");
+               printk(KERN_ERR DRVNAME ": unable to register misc device\n");
                goto out_register;
        }
        goto out;
 
 out_register:
-       misc_deregister(&ar7_wdt_miscdev);
+       unregister_reboot_notifier(&ar7_wdt_notifier);
 out_alloc:
+       iounmap(ar7_wdt);
        release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
 out:
        return rc;
@@ -338,8 +339,8 @@ out:
 
 static void __exit ar7_wdt_cleanup(void)
 {
-       unregister_reboot_notifier(&ar7_wdt_notifier);
        misc_deregister(&ar7_wdt_miscdev);
+       unregister_reboot_notifier(&ar7_wdt_notifier);
        iounmap(ar7_wdt);
        release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
 }