1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/watchdog/wafer5823wdt.c b/drivers/watchdog/wafer5823wdt.c
new file mode 100644
index 000000000..a8a1ed215
--- /dev/null
+++ b/drivers/watchdog/wafer5823wdt.c
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	ICP Wafer 5823 Single Board Computer WDT driver
+ *	http://www.icpamerica.com/wafer_5823.php
+ *	May also work on other similar models
+ *
+ *	(c) Copyright 2002 Justin Cormack <justin@street-vision.com>
+ *
+ *	Release 0.02
+ *
+ *	Based on advantechwdt.c which is based on wdt.c.
+ *	Original copyright messages:
+ *
+ *	(c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ *						All Rights Reserved.
+ *
+ *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
+ *	warranty for any of this software. This material is provided
+ *	"AS-IS" and at no charge.
+ *
+ *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/ioport.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#define WATCHDOG_NAME "Wafer 5823 WDT"
+#define PFX WATCHDOG_NAME ": "
+#define WD_TIMO 60			/* 60 sec default timeout */
+
+static unsigned long wafwdt_is_open;
+static char expect_close;
+static DEFINE_SPINLOCK(wafwdt_lock);
+
+/*
+ *	You must set these - there is no sane way to probe for this board.
+ *
+ *	To enable, write the timeout value in seconds (1 to 255) to I/O
+ *	port WDT_START, then read the port to start the watchdog. To pat
+ *	the dog, read port WDT_STOP to stop the timer, then read WDT_START
+ *	to restart it again.
+ */
+
+static int wdt_stop = 0x843;
+static int wdt_start = 0x443;
+
+static int timeout = WD_TIMO;  /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+		"Watchdog timeout in seconds. 1 <= timeout <= 255, default="
+				__MODULE_STRING(WD_TIMO) ".");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+		"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static void wafwdt_ping(void)
+{
+	/* pat watchdog */
+	spin_lock(&wafwdt_lock);
+	inb_p(wdt_stop);
+	inb_p(wdt_start);
+	spin_unlock(&wafwdt_lock);
+}
+
+static void wafwdt_start(void)
+{
+	/* start up watchdog */
+	outb_p(timeout, wdt_start);
+	inb_p(wdt_start);
+}
+
+static void wafwdt_stop(void)
+{
+	/* stop watchdog */
+	inb_p(wdt_stop);
+}
+
+static ssize_t wafwdt_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	/* See if we got the magic character 'V' and reload the timer */
+	if (count) {
+		if (!nowayout) {
+			size_t i;
+
+			/* In case it was set long ago */
+			expect_close = 0;
+
+			/* scan to see whether or not we got the magic
+			   character */
+			for (i = 0; i != count; i++) {
+				char c;
+				if (get_user(c, buf + i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 42;
+			}
+		}
+		/* Well, anyhow someone wrote to us, we should
+		   return that favour */
+		wafwdt_ping();
+	}
+	return count;
+}
+
+static long wafwdt_ioctl(struct file *file, unsigned int cmd,
+							unsigned long arg)
+{
+	int new_timeout;
+	void __user *argp = (void __user *)arg;
+	int __user *p = argp;
+	static const struct watchdog_info ident = {
+		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
+							WDIOF_MAGICCLOSE,
+		.firmware_version = 1,
+		.identity = "Wafer 5823 WDT",
+	};
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user(argp, &ident, sizeof(ident)))
+			return -EFAULT;
+		break;
+
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, p);
+
+	case WDIOC_SETOPTIONS:
+	{
+		int options, retval = -EINVAL;
+
+		if (get_user(options, p))
+			return -EFAULT;
+
+		if (options & WDIOS_DISABLECARD) {
+			wafwdt_stop();
+			retval = 0;
+		}
+
+		if (options & WDIOS_ENABLECARD) {
+			wafwdt_start();
+			retval = 0;
+		}
+
+		return retval;
+	}
+
+	case WDIOC_KEEPALIVE:
+		wafwdt_ping();
+		break;
+
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_timeout, p))
+			return -EFAULT;
+		if ((new_timeout < 1) || (new_timeout > 255))
+			return -EINVAL;
+		timeout = new_timeout;
+		wafwdt_stop();
+		wafwdt_start();
+		fallthrough;
+	case WDIOC_GETTIMEOUT:
+		return put_user(timeout, p);
+
+	default:
+		return -ENOTTY;
+	}
+	return 0;
+}
+
+static int wafwdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &wafwdt_is_open))
+		return -EBUSY;
+
+	/*
+	 *      Activate
+	 */
+	wafwdt_start();
+	return stream_open(inode, file);
+}
+
+static int wafwdt_close(struct inode *inode, struct file *file)
+{
+	if (expect_close == 42)
+		wafwdt_stop();
+	else {
+		pr_crit("WDT device closed unexpectedly.  WDT will not stop!\n");
+		wafwdt_ping();
+	}
+	clear_bit(0, &wafwdt_is_open);
+	expect_close = 0;
+	return 0;
+}
+
+/*
+ *	Notifier for system down
+ */
+
+static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code,
+								void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		wafwdt_stop();
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static const struct file_operations wafwdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= wafwdt_write,
+	.unlocked_ioctl	= wafwdt_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.open		= wafwdt_open,
+	.release	= wafwdt_close,
+};
+
+static struct miscdevice wafwdt_miscdev = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &wafwdt_fops,
+};
+
+/*
+ *	The WDT needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off.
+ */
+
+static struct notifier_block wafwdt_notifier = {
+	.notifier_call = wafwdt_notify_sys,
+};
+
+static int __init wafwdt_init(void)
+{
+	int ret;
+
+	pr_info("WDT driver for Wafer 5823 single board computer initialising\n");
+
+	if (timeout < 1 || timeout > 255) {
+		timeout = WD_TIMO;
+		pr_info("timeout value must be 1 <= x <= 255, using %d\n",
+			timeout);
+	}
+
+	if (wdt_stop != wdt_start) {
+		if (!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {
+			pr_err("I/O address 0x%04x already in use\n", wdt_stop);
+			ret = -EIO;
+			goto error;
+		}
+	}
+
+	if (!request_region(wdt_start, 1, "Wafer 5823 WDT")) {
+		pr_err("I/O address 0x%04x already in use\n", wdt_start);
+		ret = -EIO;
+		goto error2;
+	}
+
+	ret = register_reboot_notifier(&wafwdt_notifier);
+	if (ret != 0) {
+		pr_err("cannot register reboot notifier (err=%d)\n", ret);
+		goto error3;
+	}
+
+	ret = misc_register(&wafwdt_miscdev);
+	if (ret != 0) {
+		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+		       WATCHDOG_MINOR, ret);
+		goto error4;
+	}
+
+	pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
+		timeout, nowayout);
+
+	return ret;
+error4:
+	unregister_reboot_notifier(&wafwdt_notifier);
+error3:
+	release_region(wdt_start, 1);
+error2:
+	if (wdt_stop != wdt_start)
+		release_region(wdt_stop, 1);
+error:
+	return ret;
+}
+
+static void __exit wafwdt_exit(void)
+{
+	misc_deregister(&wafwdt_miscdev);
+	unregister_reboot_notifier(&wafwdt_notifier);
+	if (wdt_stop != wdt_start)
+		release_region(wdt_stop, 1);
+	release_region(wdt_start, 1);
+}
+
+module_init(wafwdt_init);
+module_exit(wafwdt_exit);
+
+MODULE_AUTHOR("Justin Cormack");
+MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");
+MODULE_LICENSE("GPL");
+
+/* end of wafer5823wdt.c */