[PATCH] Winbond w83627hf driver

From: Pádraig Brady <P@draigBrady.com>

Watchdog driver for the Winbond w83627hf which is on the last 3 motherboards
I got here for test (tyan, advantech, force).

Documentation/watchdog/watchdog-api.txt

@@ -358,6 +358,15 @@ w83877f_wdt.c -- W83877F Computer
 
 	No bits set in GETSUPPORT
 
+w83627hf_wdt.c -- w83627hf watchdog
+
+	Timeout that defaults to 60 seconds, supports SETTIMEOUT.
+
+	Supports CONFIG_WATCHDOG_NOWAYOUT
+
+	GETSUPPORT returns WDIOF_KEEPALIVEPING and WDIOF_SETTIMEOUT.
+	The GETSTATUS call returns if the device is open or not.
+
 wdt.c -- ICS WDT500/501 ISA and
 wdt_pci.c -- ICS WDT500/501 PCI
 

drivers/char/watchdog/Kconfig

@@ -276,6 +276,21 @@ config W83877F_WDT
 
 	  Most people will say N.
 
+config W83627HF_WDT
+	tristate "W83627HF Watchdog Timer"
+	depends on WATCHDOG
+	---help---
+	  This is the driver for the hardware watchdog on the W83627HF chipset
+	  as used in Advantech PC-9578 and Tyan S2721-533 motherboards
+	  (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 w83627hf_wdt.
+
+	  Most people will say N.
+
 config MACHZ_WDT
 	tristate "ZF MachZ Watchdog"
 	depends on WATCHDOG

drivers/char/watchdog/Makefile

@@ -25,6 +25,7 @@ obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o
 obj-$(CONFIG_EUROTECH_WDT) += eurotechwdt.o
 obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
 obj-$(CONFIG_W83877F_WDT) += w83877f_wdt.o
+obj-$(CONFIG_W83627HF_WDT) += w83627hf_wdt.o
 obj-$(CONFIG_SC520_WDT) += sc520_wdt.o
 obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o
 obj-$(CONFIG_ALIM1535_WDT) += alim1535_wdt.o

drivers/char/watchdog/w83627hf_wdt.c

+/*
+ *	w83627hf WDT driver
+ *
+ *	(c) Copyright 2003 Pdraig Brady <P@draigBrady.com>
+ *
+ *	Based on advantechwdt.c which is based on wdt.c.
+ *	Original copyright messages:
+ *
+ *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
+ *
+ *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
+ *				http://www.redhat.com
+ *
+ *	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.
+ *
+ *	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@redhat.com>
+ */
+
+#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 <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#define WATCHDOG_NAME "w83627hf WDT"
+#define PFX WATCHDOG_NAME ": "
+#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */
+
+static unsigned long wdt_is_open;
+static char expect_close;
+
+/* You must set this - there is no sane way to probe for this board. */
+static int wdt_io = 0x2E;
+module_param(wdt_io, int, 0);
+MODULE_PARM_DESC(wdt_io, "w83627hf WDT io port (default 0x2E)");
+
+static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ *	Kernel methods.
+ */
+
+#define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
+#define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register (same as EFER) */
+#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
+
+static void
+wdt_ctrl(int timeout)
+{
+	outb_p(0x87, WDT_EFER); /* Enter extended function mode */
+	outb_p(0x87, WDT_EFER); /* Again according to manual */
+
+	outb_p(0x07, WDT_EFER); /* point to logical device number reg */
+	outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
+	outb_p(0x30, WDT_EFER); /* select CR30 */
+	outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
+
+	outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
+	outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
+
+	outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
+}
+
+static void
+wdt_ping(void)
+{
+	wdt_ctrl(timeout);
+}
+
+static void
+wdt_disable(void)
+{
+	wdt_ctrl(0);
+}
+
+static ssize_t
+wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
+{
+	/*  Can't seek (pwrite) on this device  */
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	if (count) {
+		if (!nowayout) {
+			size_t i;
+
+			expect_close = 0;
+
+			for (i = 0; i != count; i++) {
+				char c;
+				if (get_user(c, buf+i))
+					return -EFAULT;
+				if (c == 'V')
+					expect_close = 42;
+			}
+		}
+		wdt_ping();
+	}
+	return count;
+}
+
+static int
+wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+	  unsigned long arg)
+{
+	int new_timeout;
+	static struct watchdog_info ident = {
+		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
+		.firmware_version = 1,
+		.identity = "Advantech WDT",
+	};
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+	  if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
+	    return -EFAULT;
+	  break;
+
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+	  return put_user(0, (int *)arg);
+
+	case WDIOC_KEEPALIVE:
+	  wdt_ping();
+	  break;
+
+	case WDIOC_SETTIMEOUT:
+	  if (get_user(new_timeout, (int *)arg))
+		  return -EFAULT;
+	  if ((new_timeout < 1) || (new_timeout > 63))
+		  return -EINVAL;
+	  timeout = new_timeout;
+	  wdt_ping();
+	  /* Fall */
+
+	case WDIOC_GETTIMEOUT:
+	  return put_user(timeout, (int *)arg);
+
+	case WDIOC_SETOPTIONS:
+	{
+	  int options, retval = -EINVAL;
+
+	  if (get_user(options, (int *)arg))
+	    return -EFAULT;
+
+	  if (options & WDIOS_DISABLECARD) {
+	    wdt_disable();
+	    retval = 0;
+	  }
+
+	  if (options & WDIOS_ENABLECARD) {
+	    wdt_ping();
+	    retval = 0;
+	  }
+
+	  return retval;
+	}
+
+	default:
+	  return -ENOTTY;
+	}
+	return 0;
+}
+
+static int
+wdt_open(struct inode *inode, struct file *file)
+{
+	if (test_and_set_bit(0, &wdt_is_open))
+		return -EBUSY;
+	/*
+	 *	Activate
+	 */
+
+	wdt_ping();
+	return 0;
+}
+
+static int
+wdt_close(struct inode *inode, struct file *file)
+{
+	if (expect_close == 42) {
+		wdt_disable();
+	} else {
+		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+		wdt_ping();
+	}
+	clear_bit(0, &wdt_is_open);
+	expect_close = 0;
+	return 0;
+}
+
+/*
+ *	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) {
+		/* Turn the WDT off */
+		wdt_disable();
+	}
+	return NOTIFY_DONE;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static struct file_operations wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= wdt_write,
+	.ioctl		= wdt_ioctl,
+	.open		= wdt_open,
+	.release	= wdt_close,
+};
+
+static struct miscdevice wdt_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name = "watchdog",
+	.fops = &wdt_fops,
+};
+
+/*
+ *	The WDT needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off.
+ */
+
+static struct notifier_block wdt_notifier = {
+	.notifier_call = wdt_notify_sys,
+	.next = NULL,
+	.priority = 0,
+};
+
+static int __init
+wdt_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
+
+	if (timeout < 1 || timeout > 63) {
+		timeout = WATCHDOG_TIMEOUT;
+		printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
+			timeout);
+	}
+
+	if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
+		printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
+			wdt_io);
+		ret = -EIO;
+		goto out;
+	}
+
+	ret = register_reboot_notifier(&wdt_notifier);
+	if (ret != 0) {
+		printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+			ret);
+		goto unreg_regions;
+	}
+
+	ret = misc_register(&wdt_miscdev);
+	if (ret != 0) {
+		printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+			WATCHDOG_MINOR, ret);
+		goto unreg_reboot;
+	}
+
+	printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
+		timeout, nowayout);
+
+out:
+	return ret;
+unreg_reboot:
+	unregister_reboot_notifier(&wdt_notifier);
+unreg_regions:
+	release_region(wdt_io, 1);
+	goto out;
+}
+
+static void __exit
+wdt_exit(void)
+{
+	misc_deregister(&wdt_miscdev);
+	unregister_reboot_notifier(&wdt_notifier);
+	release_region(wdt_io,1);
+}
+
+module_init(wdt_init);
+module_exit(wdt_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pdraig Brady <P@draigBrady.com>");
+MODULE_DESCRIPTION("w38627hf WDT driver");
+