3 files changed, 239 insertions, 0 deletions

diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig
index a6544790af60..f68aaa60fa8f 100644
--- a/drivers/char/watchdog/Kconfig
+++ b/drivers/char/watchdog/Kconfig
@@ -395,6 +395,28 @@ config MACHZ_WDT
           To compile this driver as a module, choose M here: the
           module will be called machzwd.
 
+config SBC_EPX_C3_WATCHDOG
+        tristate "Winsystems SBC EPX-C3 watchdog"
+        depends on WATCHDOG && X86
+        ---help---
+          This is the driver for the built-in watchdog timer on the EPX-C3
+          Single-board computer made by Winsystems, Inc.
+
+          *Note*: This hardware watchdog is not probeable and thus there
+          is no way to know if writing to its IO address will corrupt
+          your system or have any real effect.  The only way to be sure
+          that this driver does what you want is to make sure you
+          are runnning it on an EPX-C3 from Winsystems with the watchdog
+          timer at IO address 0x1ee and 0x1ef.  It will write to both those
+          IO ports.  Basically, the assumption is made that if you compile
+          this driver into your kernel and/or load it as a module, that you
+          know what you are doing and that you are in fact running on an
+          EPX-C3 board!
+
+          To compile this driver as a module, choose M here: the
+          module will be called sbc_epx_c3.
+
+
 # PowerPC Architecture
 
 config 8xx_WDT
diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile
index cfd0a3987710..4fa2ca8e943c 100644
--- a/drivers/char/watchdog/Makefile
+++ b/drivers/char/watchdog/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_W83627HF_WDT) += w83627hf_wdt.o
 obj-$(CONFIG_W83877F_WDT) += w83877f_wdt.o
 obj-$(CONFIG_W83977F_WDT) += w83977f_wdt.o
 obj-$(CONFIG_MACHZ_WDT) += machzwd.o
+obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
 
 # PowerPC Architecture
 obj-$(CONFIG_8xx_WDT) += mpc8xx_wdt.o
diff --git a/drivers/char/watchdog/sbc_epx_c3.c b/drivers/char/watchdog/sbc_epx_c3.c
new file mode 100644
index 000000000000..951764614ebf
--- /dev/null
+++ b/drivers/char/watchdog/sbc_epx_c3.c
@@ -0,0 +1,216 @@
+/*
+ *      SBC EPX C3 0.1  A Hardware Watchdog Device for the Winsystems EPX-C3
+ *      single board computer
+ *
+ *      (c) Copyright 2006 Calin A. Culianu <calin@ajvar.org>, All Rights
+ *      Reserved.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify 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.
+ *
+ *      based on softdog.c by Alan Cox <alan@redhat.com>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#define PFX "epx_c3: "
+static int epx_c3_alive;
+
+#define WATCHDOG_TIMEOUT 1              /* 1 sec default timeout */
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+#define EPXC3_WATCHDOG_CTL_REG 0x1ee /* write 1 to enable, 0 to disable */
+#define EPXC3_WATCHDOG_PET_REG 0x1ef /* write anything to pet once enabled */
+
+static void epx_c3_start(void)
+{
+        outb(1, EPXC3_WATCHDOG_CTL_REG);
+}
+
+static void epx_c3_stop(void)
+{
+
+        outb(0, EPXC3_WATCHDOG_CTL_REG);
+
+        printk(KERN_INFO PFX "Stopped watchdog timer.\n");
+}
+
+static void epx_c3_pet(void)
+{
+        outb(1, EPXC3_WATCHDOG_PET_REG);
+}
+
+/*
+ *      Allow only one person to hold it open
+ */
+static int epx_c3_open(struct inode *inode, struct file *file)
+{
+        if (epx_c3_alive)
+                return -EBUSY;
+
+        if (nowayout)
+                __module_get(THIS_MODULE);
+
+        /* Activate timer */
+        epx_c3_start();
+        epx_c3_pet();
+
+        epx_c3_alive = 1;
+        printk(KERN_INFO "Started watchdog timer.\n");
+
+        return nonseekable_open(inode, file);
+}
+
+static int epx_c3_release(struct inode *inode, struct file *file)
+{
+        /* Shut off the timer.
+         * Lock it in if it's a module and we defined ...NOWAYOUT */
+        if (!nowayout)
+                epx_c3_stop();          /* Turn the WDT off */
+
+        epx_c3_alive = 0;
+
+        return 0;
+}
+
+static ssize_t epx_c3_write(struct file *file, const char *data,
+                        size_t len, loff_t *ppos)
+{
+        /* Refresh the timer. */
+        if (len)
+                epx_c3_pet();
+        return len;
+}
+
+static int epx_c3_ioctl(struct inode *inode, struct file *file,
+                        unsigned int cmd, unsigned long arg)
+{
+        int options, retval = -EINVAL;
+        static struct watchdog_info ident = {
+                .options                = WDIOF_KEEPALIVEPING |
+                                          WDIOF_MAGICCLOSE,
+                .firmware_version       = 0,
+                .identity               = "Winsystems EPX-C3 H/W Watchdog",
+        };
+
+        switch (cmd) {
+        case WDIOC_GETSUPPORT:
+                if (copy_to_user((struct watchdog_info *)arg,
+                                 &ident, sizeof(ident)))
+                        return -EFAULT;
+                return 0;
+        case WDIOC_GETSTATUS:
+        case WDIOC_GETBOOTSTATUS:
+                return put_user(0,(int *)arg);
+        case WDIOC_KEEPALIVE:
+                epx_c3_pet();
+                return 0;
+        case WDIOC_GETTIMEOUT:
+                return put_user(WATCHDOG_TIMEOUT,(int *)arg);
+        case WDIOC_SETOPTIONS: {
+                if (get_user(options, (int *)arg))
+                        return -EFAULT;
+
+                if (options & WDIOS_DISABLECARD) {
+                        epx_c3_stop();
+                        retval = 0;
+                }
+
+                if (options & WDIOS_ENABLECARD) {
+                        epx_c3_start();
+                        retval = 0;
+                }
+
+                return retval;
+        }
+        default:
+                return -ENOIOCTLCMD;
+        }
+}
+
+static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code,
+                                void *unused)
+{
+        if (code == SYS_DOWN || code == SYS_HALT)
+                epx_c3_stop();          /* Turn the WDT off */
+
+        return NOTIFY_DONE;
+}
+
+static struct file_operations epx_c3_fops = {
+        .owner          = THIS_MODULE,
+        .llseek         = no_llseek,
+        .write          = epx_c3_write,
+        .ioctl          = epx_c3_ioctl,
+        .open           = epx_c3_open,
+        .release        = epx_c3_release,
+};
+
+static struct miscdevice epx_c3_miscdev = {
+        .minor          = WATCHDOG_MINOR,
+        .name           = "watchdog",
+        .fops           = &epx_c3_fops,
+};
+
+static struct notifier_block epx_c3_notifier = {
+        .notifier_call = epx_c3_notify_sys,
+};
+
+static const char banner[] __initdata =
+    KERN_INFO PFX "Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n";
+
+static int __init watchdog_init(void)
+{
+        int ret;
+
+        ret = register_reboot_notifier(&epx_c3_notifier);
+        if (ret) {
+                printk(KERN_ERR PFX "cannot register reboot notifier "
+                        "(err=%d)\n", ret);
+                return ret;
+        }
+
+        ret = misc_register(&epx_c3_miscdev);
+        if (ret) {
+                printk(KERN_ERR PFX "cannot register miscdev on minor=%d "
+                        "(err=%d)\n", WATCHDOG_MINOR, ret);
+                unregister_reboot_notifier(&epx_c3_notifier);
+                return ret;
+        }
+
+        printk(banner);
+
+        return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+        misc_deregister(&epx_c3_miscdev);
+        unregister_reboot_notifier(&epx_c3_notifier);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);
+
+MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>");
+MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC.  Note that there is no way to probe for this device -- so only use it if you are *sure* you are runnning on this specific SBC system from Winsystems!  It writes to IO ports 0x1ee and 0x1ef!");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);