[patch] 2.4.2 Advantech WDT driver

[patch] 2.4.2 Advantech WDT driver

[Marek Michalkiewicz]

This patch adds the Advantech WDT driver (ported from 2.2.19pre,
only minimal changes) to the 2.4.2 kernel.

Please Cc: any replies to me (I'm not subscribed to linux-kernel).

Thanks,
Marek

diff -urN v2.4.2/linux/drivers/char/Config.in linux/drivers/char/Config.in
--- v2.4.2/linux/drivers/char/Config.in	Tue Feb 13 23:13:43 2001
+++ linux/drivers/char/Config.in	Tue Feb 27 10:33:31 2001
@@ -133,6 +133,7 @@
    fi
    tristate '  Berkshire Products PC Watchdog' CONFIG_PCWATCHDOG
    tristate '  Acquire SBC Watchdog Timer' CONFIG_ACQUIRE_WDT
+   tristate '  Advantech SBC Watchdog Timer' CONFIG_ADVANTECH_WDT
    tristate '  SBC-60XX Watchdog Timer' CONFIG_60XX_WDT
    tristate '  Mixcom Watchdog' CONFIG_MIXCOMWD 
    tristate '  Intel i810 TCO timer / Watchdog' CONFIG_I810_TCO
diff -urN v2.4.2/linux/drivers/char/Makefile linux/drivers/char/Makefile
--- v2.4.2/linux/drivers/char/Makefile	Thu Jan  4 22:00:55 2001
+++ linux/drivers/char/Makefile	Tue Feb 27 10:34:28 2001
@@ -177,6 +177,7 @@
 
 obj-$(CONFIG_PCWATCHDOG) += pcwd.o
 obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
+obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
 obj-$(CONFIG_MIXCOMWD) += mixcomwd.o
 obj-$(CONFIG_60XX_WDT) += sbc60xxwdt.o
 obj-$(CONFIG_WDT) += wdt.o
diff -urN v2.4.2/linux/drivers/char/advantechwdt.c linux/drivers/char/advantechwdt.c
--- v2.4.2/linux/drivers/char/advantechwdt.c	Thu Jan  1 01:00:00 1970
+++ linux/drivers/char/advantechwdt.c	Tue Feb 27 11:07:22 2001
@@ -0,0 +1,241 @@
+/*
+ *	Advantech Single Board Computer WDT driver for Linux 2.4.x
+ *
+ *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
+ *
+ *	Based on acquirewdt.c which is based on wdt.c.
+ *	Original copyright messages:
+ *
+ *	(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/config.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/smp_lock.h>
+
+static int advwdt_is_open;
+static spinlock_t advwdt_lock;
+
+/*
+ *	You must set these - there is no sane way to probe for this board.
+ *
+ *	To enable or restart, write the timeout value in seconds (1 to 63)
+ *	to I/O port WDT_START.  To disable, read I/O port WDT_STOP.
+ *	Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
+ *	check your manual (at least the PCA-6159 seems to be different -
+ *	the manual says WDT_STOP is 0x43, not 0x443).
+ *	(0x43 is also a write-only control register for the 8254 timer!)
+ *
+ *	TODO: module parameters to set the I/O port addresses and NOWAYOUT
+ *	option at load time.
+ */
+ 
+#define WDT_STOP 0x443
+#define WDT_START 0x443
+
+#define WD_TIMO 60		/* 1 minute */
+
+/*
+ *	Kernel methods.
+ */
+ 
+static void
+advwdt_ping(void)
+{
+	/* Write a watchdog value */
+	outb_p(WD_TIMO, WDT_START);
+}
+
+static ssize_t
+advwdt_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) {
+		advwdt_ping();
+		return 1;
+	}
+	return 0;
+}
+
+static ssize_t
+advwdt_read(struct file *file, char *buf, size_t count, loff_t *ppos)
+{
+	return -EINVAL;
+}
+
+static int
+advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+	  unsigned long arg)
+{
+	static struct watchdog_info ident = {
+		WDIOF_KEEPALIVEPING, 1, "Advantech WDT"
+	};
+	
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+	  if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
+	    return -EFAULT;
+	  break;
+	  
+	case WDIOC_GETSTATUS:
+	  if (copy_to_user((int *)arg, &advwdt_is_open,  sizeof(int)))
+	    return -EFAULT;
+	  break;
+
+	case WDIOC_KEEPALIVE:
+	  advwdt_ping();
+	  break;
+
+	default:
+	  return -ENOIOCTLCMD;
+	}
+	return 0;
+}
+
+static int
+advwdt_open(struct inode *inode, struct file *file)
+{
+	switch (MINOR(inode->i_rdev)) {
+		case WATCHDOG_MINOR:
+			spin_lock(&advwdt_lock);
+			if (advwdt_is_open) {
+				spin_unlock(&advwdt_lock);
+				return -EBUSY;
+			}
+			/*
+			 *	Activate 
+			 */
+	 
+			advwdt_is_open = 1;
+			advwdt_ping();
+			spin_unlock(&advwdt_lock);
+			return 0;
+		default:
+			return -ENODEV;
+	}
+}
+
+static int
+advwdt_close(struct inode *inode, struct file *file)
+{
+	lock_kernel();
+	if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
+		spin_lock(&advwdt_lock);
+#ifndef CONFIG_WATCHDOG_NOWAYOUT	
+		inb_p(WDT_STOP);
+#endif		
+		advwdt_is_open = 0;
+		spin_unlock(&advwdt_lock);
+	}
+	unlock_kernel();
+	return 0;
+}
+
+/*
+ *	Notifier for system down
+ */
+
+static int
+advwdt_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT) {
+		/* Turn the WDT off */
+		inb_p(WDT_STOP);
+	}
+	return NOTIFY_DONE;
+}
+ 
+/*
+ *	Kernel Interfaces
+ */
+ 
+static struct file_operations advwdt_fops = {
+	owner:		THIS_MODULE,
+	read:		advwdt_read,
+	write:		advwdt_write,
+	ioctl:		advwdt_ioctl,
+	open:		advwdt_open,
+	release:	advwdt_close,
+};
+
+static struct miscdevice advwdt_miscdev = {
+	WATCHDOG_MINOR,
+	"watchdog",
+	&advwdt_fops
+};
+
+/*
+ *	The WDT needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off. 
+ */
+ 
+static struct notifier_block advwdt_notifier = {
+	advwdt_notify_sys,
+	NULL,
+	0
+};
+
+static int __init
+advwdt_init(void)
+{
+	printk("WDT driver for Advantech single board computer initialising.\n");
+
+	spin_lock_init(&advwdt_lock);
+	misc_register(&advwdt_miscdev);
+#if WDT_START != WDT_STOP
+	request_region(WDT_STOP, 1, "Advantech WDT");
+#endif
+	request_region(WDT_START, 1, "Advantech WDT");
+	register_reboot_notifier(&advwdt_notifier);
+	return 0;
+}
+
+static void __exit
+advwdt_exit(void)
+{
+	misc_deregister(&advwdt_miscdev);
+	unregister_reboot_notifier(&advwdt_notifier);
+#if WDT_START != WDT_STOP
+	release_region(WDT_STOP,1);
+#endif
+	release_region(WDT_START,1);
+}
+
+module_init(advwdt_init);
+module_exit(advwdt_exit);
+
+/* end of advantechwdt.c */

Re: [patch] 2.4.2 Advantech WDT driver

[Jeff Garzik]

Marek Michalkiewicz wrote:
> +static int
> +advwdt_close(struct inode *inode, struct file *file)
> +{
> +       lock_kernel();
> +       if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
> +               spin_lock(&advwdt_lock);
> +#ifndef CONFIG_WATCHDOG_NOWAYOUT
> +               inb_p(WDT_STOP);
> +#endif
> +               advwdt_is_open = 0;
> +               spin_unlock(&advwdt_lock);
> +       }
> +       unlock_kernel();
> +       return 0;
> +}

Why is lock_kernel necessary?


> +static int __init
> +advwdt_init(void)
> +{
> +       printk("WDT driver for Advantech single board computer initialising.\n");
> +
> +       spin_lock_init(&advwdt_lock);
> +       misc_register(&advwdt_miscdev);

check return code for error


> +#if WDT_START != WDT_STOP
> +       request_region(WDT_STOP, 1, "Advantech WDT");
> +#endif
> +       request_region(WDT_START, 1, "Advantech WDT");

check return..


> +       register_reboot_notifier(&advwdt_notifier);

ditto



-- 
Jeff Garzik       | "You see, in this world there's two kinds of
Building 1024     |  people, my friend: Those with loaded guns
MandrakeSoft      |  and those who dig. You dig."  --Blondie

Re: [patch] 2.4.2 Advantech WDT driver

[Marek Michalkiewicz]

> Why is lock_kernel necessary?

Well, it is there in 2.4.2 acquirewdt.c (which this driver is based on -
really only minimal changes, the hardware is only slightly different).
I can remove it if you tell me it's really not necessary.

> > +       spin_lock_init(&advwdt_lock);
> > +       misc_register(&advwdt_miscdev);
> 
> check return code for error

Again, acquirewdt.c doesn't do it with the misc_register, request_region
and register_reboot_notifier calls.  (Should it?  Cc: Alan Cox)

Thanks,
Marek

Re: [patch] 2.4.2 Advantech WDT driver

[Jeff Garzik]

Marek Michalkiewicz wrote:
> 
> > Why is lock_kernel necessary?
> 
> Well, it is there in 2.4.2 acquirewdt.c (which this driver is based on -
> really only minimal changes, the hardware is only slightly different).
> I can remove it if you tell me it's really not necessary.

Sounds like it got caught in an audit and is necessary, I didn't look
closely...


> > > +       spin_lock_init(&advwdt_lock);
> > > +       misc_register(&advwdt_miscdev);
> >
> > check return code for error
> 
> Again, acquirewdt.c doesn't do it with the misc_register, request_region
> and register_reboot_notifier calls.  (Should it?  Cc: Alan Cox)

Yes, the return codes should be checked.  :)

-- 
Jeff Garzik       | "You see, in this world there's two kinds of
Building 1024     |  people, my friend: Those with loaded guns
MandrakeSoft      |  and those who dig. You dig."  --Blondie