1 files changed, 476 insertions, 0 deletions
diff --git a/drivers/watchdog/eurotechwdt.c b/drivers/watchdog/eurotechwdt.c
new file mode 100644
index 000000000..e26609ad4
--- /dev/null
+++ b/drivers/watchdog/eurotechwdt.c
@@ -0,0 +1,476 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	Eurotech CPU-1220/1410/1420 on board WDT driver
+ *
+ *	(c) Copyright 2001 Ascensit <support@ascensit.com>
+ *	(c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com>
+ *	(c) Copyright 2002 Rob Radez <rob@osinvestor.com>
+ *
+ *	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>*
+ */
+
+/* Changelog:
+ *
+ * 2001 - Rodolfo Giometti
+ *	Initial release
+ *
+ * 2002/04/25 - Rob Radez
+ *	clean up #includes
+ *	clean up locking
+ *	make __setup param unique
+ *	proper options in watchdog_info
+ *	add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls
+ *	add expect_close support
+ *
+ * 2002.05.30 - Joel Becker <joel.becker@oracle.com>
+ *	Added Matt Domsch's nowayout module option.
+ */
+
+/*
+ *	The eurotech CPU-1220/1410/1420's watchdog is a part
+ *	of the on-board SUPER I/O device SMSC FDC 37B782.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.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/io.h>
+#include <linux/uaccess.h>
+
+
+static unsigned long eurwdt_is_open;
+static int eurwdt_timeout;
+static char eur_expect_close;
+static DEFINE_SPINLOCK(eurwdt_lock);
+
+/*
+ * You must set these - there is no sane way to probe for this board.
+ */
+
+static int io = 0x3f0;
+static int irq = 10;
+static char *ev = "int";
+
+#define WDT_TIMEOUT		60                /* 1 minute */
+
+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) ")");
+
+/*
+ * Some symbolic names
+ */
+
+#define WDT_CTRL_REG		0x30
+#define WDT_OUTPIN_CFG		0xe2
+#define WDT_EVENT_INT		0x00
+#define WDT_EVENT_REBOOT	0x08
+#define WDT_UNIT_SEL		0xf1
+#define WDT_UNIT_SECS		0x80
+#define WDT_TIMEOUT_VAL		0xf2
+#define WDT_TIMER_CFG		0xf3
+
+
+module_param_hw(io, int, ioport, 0);
+MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
+module_param_hw(irq, int, irq, 0);
+MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
+module_param(ev, charp, 0);
+MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
+
+
+/*
+ * Programming support
+ */
+
+static inline void eurwdt_write_reg(u8 index, u8 data)
+{
+	outb(index, io);
+	outb(data, io+1);
+}
+
+static inline void eurwdt_lock_chip(void)
+{
+	outb(0xaa, io);
+}
+
+static inline void eurwdt_unlock_chip(void)
+{
+	outb(0x55, io);
+	eurwdt_write_reg(0x07, 0x08);	/* set the logical device */
+}
+
+static inline void eurwdt_set_timeout(int timeout)
+{
+	eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
+}
+
+static inline void eurwdt_disable_timer(void)
+{
+	eurwdt_set_timeout(0);
+}
+
+static void eurwdt_activate_timer(void)
+{
+	eurwdt_disable_timer();
+	eurwdt_write_reg(WDT_CTRL_REG, 0x01);	/* activate the WDT */
+	eurwdt_write_reg(WDT_OUTPIN_CFG,
+		!strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
+
+	/* Setting interrupt line */
+	if (irq == 2 || irq > 15 || irq < 0) {
+		pr_err("invalid irq number\n");
+		irq = 0;	/* if invalid we disable interrupt */
+	}
+	if (irq == 0)
+		pr_info("interrupt disabled\n");
+
+	eurwdt_write_reg(WDT_TIMER_CFG, irq << 4);
+
+	eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS);	/* we use seconds */
+	eurwdt_set_timeout(0);	/* the default timeout */
+}
+
+
+/*
+ * Kernel methods.
+ */
+
+static irqreturn_t eurwdt_interrupt(int irq, void *dev_id)
+{
+	pr_crit("timeout WDT timeout\n");
+
+#ifdef ONLY_TESTING
+	pr_crit("Would Reboot\n");
+#else
+	pr_crit("Initiating system reboot\n");
+	emergency_restart();
+#endif
+	return IRQ_HANDLED;
+}
+
+
+/**
+ * eurwdt_ping:
+ *
+ * Reload counter one with the watchdog timeout.
+ */
+
+static void eurwdt_ping(void)
+{
+	/* Write the watchdog default value */
+	eurwdt_set_timeout(eurwdt_timeout);
+}
+
+/**
+ * eurwdt_write:
+ * @file: file handle to the watchdog
+ * @buf: buffer to write (unused as data does not matter here
+ * @count: count of bytes
+ * @ppos: pointer to the position to write. No seeks allowed
+ *
+ * A write to a watchdog device is defined as a keepalive signal. Any
+ * write of data will do, as we don't define content meaning.
+ */
+
+static ssize_t eurwdt_write(struct file *file, const char __user *buf,
+size_t count, loff_t *ppos)
+{
+	if (count) {
+		if (!nowayout) {
+			size_t i;
+
+			eur_expect_close = 0;
+
+			for (i = 0; i != count; i++) {
+				char c;
+				if (get_user(c, buf + i))
+					return -EFAULT;
+				if (c == 'V')
+					eur_expect_close = 42;
+			}
+		}
+		spin_lock(&eurwdt_lock);
+		eurwdt_ping();	/* the default timeout */
+		spin_unlock(&eurwdt_lock);
+	}
+	return count;
+}
+
+/**
+ * eurwdt_ioctl:
+ * @file: file handle to the device
+ * @cmd: watchdog command
+ * @arg: argument pointer
+ *
+ * The watchdog API defines a common set of functions for all watchdogs
+ * according to their available features.
+ */
+
+static long eurwdt_ioctl(struct file *file,
+					unsigned int cmd, unsigned long arg)
+{
+	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	  = "WDT Eurotech CPU-1220/1410",
+	};
+
+	int time;
+	int options, retval = -EINVAL;
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, p);
+
+	case WDIOC_SETOPTIONS:
+		if (get_user(options, p))
+			return -EFAULT;
+		spin_lock(&eurwdt_lock);
+		if (options & WDIOS_DISABLECARD) {
+			eurwdt_disable_timer();
+			retval = 0;
+		}
+		if (options & WDIOS_ENABLECARD) {
+			eurwdt_activate_timer();
+			eurwdt_ping();
+			retval = 0;
+		}
+		spin_unlock(&eurwdt_lock);
+		return retval;
+
+	case WDIOC_KEEPALIVE:
+		spin_lock(&eurwdt_lock);
+		eurwdt_ping();
+		spin_unlock(&eurwdt_lock);
+		return 0;
+
+	case WDIOC_SETTIMEOUT:
+		if (copy_from_user(&time, p, sizeof(int)))
+			return -EFAULT;
+
+		/* Sanity check */
+		if (time < 0 || time > 255)
+			return -EINVAL;
+
+		spin_lock(&eurwdt_lock);
+		eurwdt_timeout = time;
+		eurwdt_set_timeout(time);
+		spin_unlock(&eurwdt_lock);
+		fallthrough;
+
+	case WDIOC_GETTIMEOUT:
+		return put_user(eurwdt_timeout, p);
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+/**
+ * eurwdt_open:
+ * @inode: inode of device
+ * @file: file handle to device
+ *
+ * The misc device has been opened. The watchdog device is single
+ * open and on opening we load the counter.
+ */
+
+static int eurwdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &eurwdt_is_open))
+		return -EBUSY;
+	eurwdt_timeout = WDT_TIMEOUT;	/* initial timeout */
+	/* Activate the WDT */
+	eurwdt_activate_timer();
+	return stream_open(inode, file);
+}
+
+/**
+ * eurwdt_release:
+ * @inode: inode to board
+ * @file: file handle to board
+ *
+ * The watchdog has a configurable API. There is a religious dispute
+ * between people who want their watchdog to be able to shut down and
+ * those who want to be sure if the watchdog manager dies the machine
+ * reboots. In the former case we disable the counters, in the latter
+ * case you have to open it again very soon.
+ */
+
+static int eurwdt_release(struct inode *inode, struct file *file)
+{
+	if (eur_expect_close == 42)
+		eurwdt_disable_timer();
+	else {
+		pr_crit("Unexpected close, not stopping watchdog!\n");
+		eurwdt_ping();
+	}
+	clear_bit(0, &eurwdt_is_open);
+	eur_expect_close = 0;
+	return 0;
+}
+
+/**
+ * eurwdt_notify_sys:
+ * @this: our notifier block
+ * @code: the event being reported
+ * @unused: unused
+ *
+ * Our notifier is called on system shutdowns. We want to turn the card
+ * off at reboot otherwise the machine will reboot again during memory
+ * test or worse yet during the following fsck. This would suck, in fact
+ * trust me - if it happens it does suck.
+ */
+
+static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		eurwdt_disable_timer();	/* Turn the card off */
+
+	return NOTIFY_DONE;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+
+static const struct file_operations eurwdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= eurwdt_write,
+	.unlocked_ioctl	= eurwdt_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.open		= eurwdt_open,
+	.release	= eurwdt_release,
+};
+
+static struct miscdevice eurwdt_miscdev = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &eurwdt_fops,
+};
+
+/*
+ * The WDT card needs to learn about soft shutdowns in order to
+ * turn the timebomb registers off.
+ */
+
+static struct notifier_block eurwdt_notifier = {
+	.notifier_call = eurwdt_notify_sys,
+};
+
+/**
+ * eurwdt_exit:
+ *
+ * Unload the watchdog. You cannot do this with any file handles open.
+ * If your watchdog is set to continue ticking on close and you unload
+ * it, well it keeps ticking. We won't get the interrupt but the board
+ * will not touch PC memory so all is fine. You just have to load a new
+ * module in 60 seconds or reboot.
+ */
+
+static void __exit eurwdt_exit(void)
+{
+	eurwdt_lock_chip();
+
+	misc_deregister(&eurwdt_miscdev);
+
+	unregister_reboot_notifier(&eurwdt_notifier);
+	release_region(io, 2);
+	free_irq(irq, NULL);
+}
+
+/**
+ * eurwdt_init:
+ *
+ * Set up the WDT watchdog board. After grabbing the resources
+ * we require we need also to unlock the device.
+ * The open() function will actually kick the board off.
+ */
+
+static int __init eurwdt_init(void)
+{
+	int ret;
+
+	ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL);
+	if (ret) {
+		pr_err("IRQ %d is not free\n", irq);
+		goto out;
+	}
+
+	if (!request_region(io, 2, "eurwdt")) {
+		pr_err("IO %X is not free\n", io);
+		ret = -EBUSY;
+		goto outirq;
+	}
+
+	ret = register_reboot_notifier(&eurwdt_notifier);
+	if (ret) {
+		pr_err("can't register reboot notifier (err=%d)\n", ret);
+		goto outreg;
+	}
+
+	ret = misc_register(&eurwdt_miscdev);
+	if (ret) {
+		pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR);
+		goto outreboot;
+	}
+
+	eurwdt_unlock_chip();
+
+	ret = 0;
+	pr_info("Eurotech WDT driver 0.01 at %X (Interrupt %d) - timeout event: %s\n",
+		io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
+
+out:
+	return ret;
+
+outreboot:
+	unregister_reboot_notifier(&eurwdt_notifier);
+
+outreg:
+	release_region(io, 2);
+
+outirq:
+	free_irq(irq, NULL);
+	goto out;
+}
+
+module_init(eurwdt_init);
+module_exit(eurwdt_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti");
+MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
+MODULE_LICENSE("GPL");