[WATCHDOG] add Nano 7240 driver
authorGilles Gigan <gilles.gigan@gmail.com>
Wed, 31 Oct 2007 06:31:42 +0000 (16:31 +1000)
committerWim Van Sebroeck <wim@iguana.be>
Tue, 4 Dec 2007 16:48:06 +0000 (16:48 +0000)
Adds support for the built-in watchdog on EPIC Nano 7240 boards from IEI.

Tested on Nano-7240RS.

Hardware documentation of the platform (including watchdog) can be found
on the IEI website: http://www.ieiworld.com

Signed-off-by: Gilles Gigan <gilles.gigan@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/Kconfig
drivers/watchdog/Makefile
drivers/watchdog/sbc7240_wdt.c [new file with mode: 0644]

index 126b554810c8f9d9ba36e1e4fedc5592ac0051ee..52dff40ec192caeea2042f07cb09021914c52c36 100644 (file)
@@ -466,6 +466,19 @@ config SBC8360_WDT
 
          Most people will say N.
 
+config SBC7240_WDT
+       tristate "SBC Nano 7240 Watchdog Timer"
+       depends on X86_32
+       ---help---
+         This is the driver for the hardware watchdog found on the IEI
+         single board computers EPIC Nano 7240 (and likely others). This
+         watchdog simply watches your kernel to make sure it doesn't freeze,
+         and if it does, it reboots your computer after a certain amount of
+         time.
+
+         To compile this driver as a module, choose M here: the
+         module will be called sbc7240_wdt.
+
 config CPU5_WDT
        tristate "SMA CPU5 Watchdog"
        depends on X86
index e4779f76b1edf41b903d45d382acf12b05931d38..87483cc63252a12b7fdf4c2b1f1f412834afbf9f 100644 (file)
@@ -72,6 +72,7 @@ obj-$(CONFIG_SCx200_WDT) += scx200_wdt.o
 obj-$(CONFIG_PC87413_WDT) += pc87413_wdt.o
 obj-$(CONFIG_60XX_WDT) += sbc60xxwdt.o
 obj-$(CONFIG_SBC8360_WDT) += sbc8360.o
+obj-$(CONFIG_SBC7240_WDT) += sbc7240_wdt.o
 obj-$(CONFIG_CPU5_WDT) += cpu5wdt.o
 obj-$(CONFIG_SMSC37B787_WDT) += smsc37b787_wdt.o
 obj-$(CONFIG_W83627HF_WDT) += w83627hf_wdt.o
diff --git a/drivers/watchdog/sbc7240_wdt.c b/drivers/watchdog/sbc7240_wdt.c
new file mode 100644 (file)
index 0000000..4c8cefb
--- /dev/null
@@ -0,0 +1,324 @@
+/*
+ *     NANO7240 SBC Watchdog device driver
+ *
+ *     Based on w83877f.c by Scott Jennings,
+ *
+ *     This program is free software; you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License version 2 as
+ *     published by the Free Software Foundation;
+ *
+ *     Software distributed under the License is distributed on an "AS IS"
+ *     basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ *     implied. See the License for the specific language governing
+ *     rights and limitations under the License.
+ *
+ *     (c) Copyright 2007  Gilles GIGAN <gilles.gigan@jcu.edu.au>
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/miscdevice.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <asm/atomic.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#define SBC7240_PREFIX "sbc7240_wdt: "
+
+#define SBC7240_ENABLE_PORT            0x443
+#define SBC7240_DISABLE_PORT           0x043
+#define SBC7240_SET_TIMEOUT_PORT       SBC7240_ENABLE_PORT
+#define SBC7240_MAGIC_CHAR             'V'
+
+#define SBC7240_TIMEOUT                30
+#define SBC7240_MAX_TIMEOUT            255
+static int timeout = SBC7240_TIMEOUT;  /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<="
+                __MODULE_STRING(SBC7240_MAX_TIMEOUT) ", default="
+                __MODULE_STRING(SBC7240_TIMEOUT) ")");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Disable watchdog when closing device file");
+
+#define SBC7240_OPEN_STATUS_BIT                0
+#define SBC7240_ENABLED_STATUS_BIT     1
+#define SBC7240_EXPECT_CLOSE_STATUS_BIT        2
+static unsigned long wdt_status;
+
+/*
+ * Utility routines
+ */
+
+static void wdt_disable(void)
+{
+       /* disable the watchdog */
+       if (test_and_clear_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status)) {
+               inb_p(SBC7240_DISABLE_PORT);
+               printk(KERN_INFO SBC7240_PREFIX
+                      "Watchdog timer is now disabled.\n");
+       }
+}
+
+static void wdt_enable(void)
+{
+       /* enable the watchdog */
+       if (!test_and_set_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status)) {
+               inb_p(SBC7240_ENABLE_PORT);
+               printk(KERN_INFO SBC7240_PREFIX
+                      "Watchdog timer is now enabled.\n");
+       }
+}
+
+static int wdt_set_timeout(int t)
+{
+       if (t < 1 || t > SBC7240_MAX_TIMEOUT) {
+               printk(KERN_ERR SBC7240_PREFIX
+                      "timeout value must be 1<=x<=%d\n",
+                      SBC7240_MAX_TIMEOUT);
+               return -1;
+       }
+       /* set the timeout */
+       outb_p((unsigned)t, SBC7240_SET_TIMEOUT_PORT);
+       timeout = t;
+       printk(KERN_INFO SBC7240_PREFIX "timeout set to %d seconds\n", t);
+       return 0;
+}
+
+/* Whack the dog */
+static inline void wdt_keepalive(void)
+{
+       if (test_bit(SBC7240_ENABLED_STATUS_BIT, &wdt_status))
+               inb_p(SBC7240_ENABLE_PORT);
+}
+
+/*
+ * /dev/watchdog handling
+ */
+static ssize_t fop_write(struct file *file, const char __user *buf,
+                        size_t count, loff_t *ppos)
+{
+       size_t i;
+       char c;
+
+       if (count) {
+               if (!nowayout) {
+                       clear_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT,
+                               &wdt_status);
+
+                       /* is there a magic char ? */
+                       for (i = 0; i != count; i++) {
+                               if (get_user(c, buf + i))
+                                       return -EFAULT;
+                               if (c == SBC7240_MAGIC_CHAR) {
+                                       set_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT,
+                                               &wdt_status);
+                                       break;
+                               }
+                       }
+               }
+
+               wdt_keepalive();
+       }
+
+       return count;
+}
+
+static int fop_open(struct inode *inode, struct file *file)
+{
+       if (test_and_set_bit(SBC7240_OPEN_STATUS_BIT, &wdt_status))
+               return -EBUSY;
+
+       wdt_enable();
+
+       return nonseekable_open(inode, file);
+}
+
+static int fop_close(struct inode *inode, struct file *file)
+{
+       if (test_and_clear_bit(SBC7240_EXPECT_CLOSE_STATUS_BIT, &wdt_status)
+           || !nowayout) {
+               wdt_disable();
+       } else {
+               printk(KERN_CRIT SBC7240_PREFIX
+                      "Unexpected close, not stopping watchdog!\n");
+               wdt_keepalive();
+       }
+
+       clear_bit(SBC7240_OPEN_STATUS_BIT, &wdt_status);
+       return 0;
+}
+
+static struct watchdog_info ident = {
+       .options = WDIOF_KEEPALIVEPING|
+                  WDIOF_SETTIMEOUT|
+                  WDIOF_MAGICCLOSE,
+       .firmware_version = 1,
+       .identity = "SBC7240",
+};
+
+
+static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+                    unsigned long arg)
+{
+       switch (cmd) {
+       case WDIOC_GETSUPPORT:
+               return copy_to_user
+                       ((void __user *)arg, &ident, sizeof(ident))
+                        ? -EFAULT : 0;
+       case WDIOC_GETSTATUS:
+       case WDIOC_GETBOOTSTATUS:
+               return put_user(0, (int __user *)arg);
+       case WDIOC_KEEPALIVE:
+               wdt_keepalive();
+               return 0;
+       case WDIOC_SETOPTIONS:{
+                       int options;
+                       int retval = -EINVAL;
+
+                       if (get_user(options, (int __user *)arg))
+                               return -EFAULT;
+
+                       if (options & WDIOS_DISABLECARD) {
+                               wdt_disable();
+                               retval = 0;
+                       }
+
+                       if (options & WDIOS_ENABLECARD) {
+                               wdt_enable();
+                               retval = 0;
+                       }
+
+                       return retval;
+               }
+       case WDIOC_SETTIMEOUT:{
+                       int new_timeout;
+
+                       if (get_user(new_timeout, (int __user *)arg))
+                               return -EFAULT;
+
+                       if (wdt_set_timeout(new_timeout))
+                               return -EINVAL;
+
+                       /* Fall through */
+               }
+       case WDIOC_GETTIMEOUT:
+               return put_user(timeout, (int __user *)arg);
+       default:
+               return -ENOTTY;
+       }
+}
+
+static const struct file_operations wdt_fops = {
+       .owner = THIS_MODULE,
+       .llseek = no_llseek,
+       .write = fop_write,
+       .open = fop_open,
+       .release = fop_close,
+       .ioctl = fop_ioctl,
+};
+
+static struct miscdevice wdt_miscdev = {
+       .minor = WATCHDOG_MINOR,
+       .name = "watchdog",
+       .fops = &wdt_fops,
+};
+
+/*
+ *     Notifier for system down
+ */
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
+                         void *unused)
+{
+       if (code == SYS_DOWN || code == SYS_HALT)
+               wdt_disable();
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block wdt_notifier = {
+       .notifier_call = wdt_notify_sys,
+};
+
+static void __exit sbc7240_wdt_unload(void)
+{
+       printk(KERN_INFO SBC7240_PREFIX "Removing watchdog\n");
+       misc_deregister(&wdt_miscdev);
+
+       unregister_reboot_notifier(&wdt_notifier);
+       release_region(SBC7240_ENABLE_PORT, 1);
+}
+
+static int __init sbc7240_wdt_init(void)
+{
+       int rc = -EBUSY;
+
+       if (!request_region(SBC7240_ENABLE_PORT, 1, "SBC7240 WDT")) {
+               printk(KERN_ERR SBC7240_PREFIX
+                      "I/O address 0x%04x already in use\n",
+                      SBC7240_ENABLE_PORT);
+               rc = -EIO;
+               goto err_out;
+       }
+
+       /* The IO port 0x043 used to disable the watchdog
+        * is already claimed by the system timer, so we
+        * cant request_region() it ...*/
+
+       if (timeout < 1 || timeout > SBC7240_MAX_TIMEOUT) {
+               timeout = SBC7240_TIMEOUT;
+               printk(KERN_INFO SBC7240_PREFIX
+                      "timeout value must be 1<=x<=%d, using %d\n",
+                      SBC7240_MAX_TIMEOUT, timeout);
+       }
+       wdt_set_timeout(timeout);
+       wdt_disable();
+
+       rc = register_reboot_notifier(&wdt_notifier);
+       if (rc) {
+               printk(KERN_ERR SBC7240_PREFIX
+                      "cannot register reboot notifier (err=%d)\n", rc);
+               goto err_out_region;
+       }
+
+       rc = misc_register(&wdt_miscdev);
+       if (rc) {
+               printk(KERN_ERR SBC7240_PREFIX
+                      "cannot register miscdev on minor=%d (err=%d)\n",
+                      wdt_miscdev.minor, rc);
+               goto err_out_reboot_notifier;
+       }
+
+       printk(KERN_INFO SBC7240_PREFIX
+              "Watchdog driver for SBC7240 initialised (nowayout=%d)\n",
+              nowayout);
+
+       return 0;
+
+err_out_reboot_notifier:
+       unregister_reboot_notifier(&wdt_notifier);
+err_out_region:
+       release_region(SBC7240_ENABLE_PORT, 1);
+err_out:
+       return rc;
+}
+
+module_init(sbc7240_wdt_init);
+module_exit(sbc7240_wdt_unload);
+
+MODULE_AUTHOR("Gilles Gigan");
+MODULE_DESCRIPTION("Watchdog device driver for single board"
+                  " computers EPIC Nano 7240 from iEi");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+