[WATCHDOG] w83977f-watchdog-driver.patch

In a project for my company I've needed to use the watchdog device in a
PCM-5335 SBC from AAEON.  The watchdog timer is from a Winbond's SuperIO
chip, the W83977F.

I've made this driver based on two others already on the kernel tree,
the w83877f_wdt and the wdt977.
Signed-off-by: NJose Goncalves <jose.goncalves@inov.pt>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

drivers/char/watchdog/Kconfig

@@ -360,6 +360,19 @@ config W83877F_WDT
 
 	  Most people will say N.
 
+config W83977F_WDT
+	tristate "W83977F (PCM-5335) Watchdog Timer"
+	depends on WATCHDOG && X86
+	---help---
+	  This is the driver for the hardware watchdog on the W83977F I/O chip
+	  as used in AAEON's PCM-5335 SBC (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 w83977f_wdt.
+
 config MACHZ_WDT
 	tristate "ZF MachZ Watchdog"
 	depends on WATCHDOG && X86

drivers/char/watchdog/Makefile

@@ -49,6 +49,7 @@ obj-$(CONFIG_SBC8360_WDT) += sbc8360.o
 obj-$(CONFIG_CPU5_WDT) += cpu5wdt.o
 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
 
 # PowerPC Architecture

drivers/char/watchdog/w83977f_wdt.c

+/*
+ *	W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
+ *
+ *	(c) Copyright 2005  Jose Goncalves <jose.goncalves@inov.pt>
+ *
+ *      Based on w83877f_wdt.c by Scott Jennings,
+ *           and wdt977.c by Woody Suwalski
+ *
+ *			-----------------------
+ *
+ *	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.
+ *
+ */
+
+#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/miscdevice.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/watchdog.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#define WATCHDOG_VERSION  "1.00"
+#define WATCHDOG_NAME     "W83977F WDT"
+#define PFX WATCHDOG_NAME ": "
+#define DRIVER_VERSION    WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
+
+#define IO_INDEX_PORT     0x3F0
+#define IO_DATA_PORT      (IO_INDEX_PORT+1)
+
+#define UNLOCK_DATA       0x87
+#define LOCK_DATA         0xAA
+#define DEVICE_REGISTER   0x07
+
+#define	DEFAULT_TIMEOUT   45		/* default timeout in seconds */
+
+static	int timeout = DEFAULT_TIMEOUT;
+static	int timeoutW;			/* timeout in watchdog counter units */
+static	unsigned long timer_alive;
+static	int testmode;
+static	char expect_close;
+static	spinlock_t spinlock;
+
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
+module_param(testmode, int, 0);
+MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
+
+#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)");
+
+/*
+ * Start the watchdog
+ */
+
+static int wdt_start(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&spinlock, flags);
+
+	/* Unlock the SuperIO chip */
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+	/*
+	 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
+	 * F2 has the timeout in watchdog counter units.
+	 * F3 is set to enable watchdog LED blink at timeout.
+	 * F4 is used to just clear the TIMEOUT'ed state (bit 0).
+	 */
+	outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+	outb_p(0x08,IO_DATA_PORT);
+	outb_p(0xF2,IO_INDEX_PORT);
+	outb_p(timeoutW,IO_DATA_PORT);
+	outb_p(0xF3,IO_INDEX_PORT);
+	outb_p(0x08,IO_DATA_PORT);
+	outb_p(0xF4,IO_INDEX_PORT);
+	outb_p(0x00,IO_DATA_PORT);
+
+	/* Set device Aux2 active */
+	outb_p(0x30,IO_INDEX_PORT);
+	outb_p(0x01,IO_DATA_PORT);
+
+	/* 
+	 * Select device Aux1 (dev=7) to set GP16 as the watchdog output
+	 * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
+	 * Map GP16 at pin 119.
+	 * In test mode watch the bit 0 on F4 to indicate "triggered" or
+	 * check watchdog LED on SBC.
+	 */
+	outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+	outb_p(0x07,IO_DATA_PORT);
+	if (!testmode)
+	{
+		unsigned pin_map;
+
+		outb_p(0xE6,IO_INDEX_PORT);
+		outb_p(0x0A,IO_DATA_PORT);
+		outb_p(0x2C,IO_INDEX_PORT);
+		pin_map = inb_p(IO_DATA_PORT);
+		pin_map |= 0x10;
+		pin_map &= ~(0x20);
+		outb_p(0x2C,IO_INDEX_PORT);
+		outb_p(pin_map,IO_DATA_PORT);
+	}
+	outb_p(0xE3,IO_INDEX_PORT);
+	outb_p(0x08,IO_DATA_PORT);
+
+	/* Set device Aux1 active */
+	outb_p(0x30,IO_INDEX_PORT);
+	outb_p(0x01,IO_DATA_PORT);
+
+	/* Lock the SuperIO chip */
+	outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+	spin_unlock_irqrestore(&spinlock, flags);
+
+	printk(KERN_INFO PFX "activated.\n");
+
+	return 0;
+}
+
+/*
+ * Stop the watchdog
+ */
+
+static int wdt_stop(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&spinlock, flags);
+
+	/* Unlock the SuperIO chip */
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+	/* 
+	 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
+	 * F2 is reset to its default value (watchdog timer disabled).
+	 * F3 is reset to its default state.
+	 * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
+	 */
+	outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+	outb_p(0x08,IO_DATA_PORT);
+	outb_p(0xF2,IO_INDEX_PORT);
+	outb_p(0xFF,IO_DATA_PORT);
+	outb_p(0xF3,IO_INDEX_PORT);
+	outb_p(0x00,IO_DATA_PORT);
+	outb_p(0xF4,IO_INDEX_PORT);
+	outb_p(0x00,IO_DATA_PORT);
+	outb_p(0xF2,IO_INDEX_PORT);
+	outb_p(0x00,IO_DATA_PORT);
+
+	/*
+	 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and 
+	 * Gp13 (in reg E3) as inputs.
+	 */
+	outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+	outb_p(0x07,IO_DATA_PORT);
+	if (!testmode)
+	{
+		outb_p(0xE6,IO_INDEX_PORT);
+		outb_p(0x01,IO_DATA_PORT);
+	}
+	outb_p(0xE3,IO_INDEX_PORT);
+	outb_p(0x01,IO_DATA_PORT);
+
+	/* Lock the SuperIO chip */
+	outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+	spin_unlock_irqrestore(&spinlock, flags);
+
+	printk(KERN_INFO PFX "shutdown.\n");
+
+	return 0;
+}
+
+/*
+ * Send a keepalive ping to the watchdog
+ * This is done by simply re-writing the timeout to reg. 0xF2
+ */
+
+static int wdt_keepalive(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&spinlock, flags);
+
+	/* Unlock the SuperIO chip */
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+	/* Select device Aux2 (device=8) to kick watchdog reg F2 */
+	outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+	outb_p(0x08,IO_DATA_PORT);
+	outb_p(0xF2,IO_INDEX_PORT);
+	outb_p(timeoutW,IO_DATA_PORT);
+
+	/* Lock the SuperIO chip */
+	outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+	spin_unlock_irqrestore(&spinlock, flags);
+
+	return 0;
+}
+
+/*
+ * Set the watchdog timeout value
+ */
+
+static int wdt_set_timeout(int t)
+{
+	int tmrval;
+
+	/*
+	 * Convert seconds to watchdog counter time units, rounding up.
+	 * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup 
+	 * value. This information is supplied in the PCM-5335 manual and was
+	 * checked by me on a real board. This is a bit strange because W83977f
+	 * datasheet says counter unit is in minutes!
+	 */
+	if (t < 15)
+		return -EINVAL;
+
+	tmrval = ((t + 15) + 29) / 30;
+
+	if (tmrval > 255)
+		return -EINVAL;
+
+	/*
+	 * timeout is the timeout in seconds, 
+	 * timeoutW is the timeout in watchdog counter units.
+	 */
+	timeoutW = tmrval;
+	timeout = (timeoutW * 30) - 15;
+	return 0;
+}
+
+/*
+ * Get the watchdog status
+ */
+
+static int wdt_get_status(int *status)
+{
+	int new_status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&spinlock, flags);
+
+	/* Unlock the SuperIO chip */
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+	outb_p(UNLOCK_DATA,IO_INDEX_PORT);
+
+	/* Select device Aux2 (device=8) to read watchdog reg F4 */
+	outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
+	outb_p(0x08,IO_DATA_PORT);
+	outb_p(0xF4,IO_INDEX_PORT);
+	new_status = inb_p(IO_DATA_PORT);
+
+	/* Lock the SuperIO chip */
+	outb_p(LOCK_DATA,IO_INDEX_PORT);
+
+	spin_unlock_irqrestore(&spinlock, flags);
+
+	*status = 0;
+	if (new_status & 1)
+		*status |= WDIOF_CARDRESET;
+
+	return 0;
+}
+
+
+/*
+ *	/dev/watchdog handling
+ */
+
+static int wdt_open(struct inode *inode, struct file *file)
+{
+	/* If the watchdog is alive we don't need to start it again */
+	if( test_and_set_bit(0, &timer_alive) )
+		return -EBUSY;
+
+	if (nowayout)
+		__module_get(THIS_MODULE);
+
+	wdt_start();
+	return nonseekable_open(inode, file);
+}
+
+static int wdt_release(struct inode *inode, struct file *file)
+{
+	/*
+	 * Shut off the timer.
+	 * Lock it in if it's a module and we set nowayout
+	 */
+	if (expect_close == 42)
+	{
+		wdt_stop();
+		clear_bit(0, &timer_alive);
+	} else {
+		wdt_keepalive();
+		printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
+	}
+	expect_close = 0;
+	return 0;
+}
+
+/*
+ *      wdt_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 we don't define content meaning.
+ */
+
+static ssize_t wdt_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 ofs;
+
+			/* note: just in case someone wrote the magic character long ago */
+			expect_close = 0;
+
+			/* scan to see whether or not we got the magic character */
+			for(ofs = 0; ofs != count; ofs++)
+			{
+				char c;
+				if (get_user(c, buf + ofs))
+					return -EFAULT;
+				if (c == 'V') {
+					expect_close = 42;
+				}
+			}
+		}
+
+		/* someone wrote to us, we should restart timer */
+		wdt_keepalive();
+	}
+	return count;
+}
+
+/*
+ *      wdt_ioctl:
+ *      @inode: inode of the device
+ *      @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 struct watchdog_info ident = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
+	.firmware_version =	1,
+	.identity = WATCHDOG_NAME,
+};
+
+static int wdt_ioctl(struct inode *inode, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	int status;
+	int new_options, retval = -EINVAL;
+	int new_timeout;
+	union {
+		struct watchdog_info __user *ident;
+		int __user *i;
+	} uarg;
+
+	uarg.i = (int __user *)arg;
+
+	switch(cmd)
+	{
+	default:
+		return -ENOIOCTLCMD;
+
+	case WDIOC_GETSUPPORT:
+		return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0;
+
+	case WDIOC_GETSTATUS:
+		wdt_get_status(&status);
+		return put_user(status, uarg.i);
+
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(0, uarg.i);
+
+	case WDIOC_KEEPALIVE:
+		wdt_keepalive();
+		return 0;
+
+	case WDIOC_SETOPTIONS:
+		if (get_user (new_options, uarg.i))
+			return -EFAULT;
+
+		if (new_options & WDIOS_DISABLECARD) {
+			wdt_stop();
+			retval = 0;
+		}
+
+		if (new_options & WDIOS_ENABLECARD) {
+			wdt_start();
+			retval = 0;
+		}
+
+		return retval;
+
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_timeout, uarg.i))
+			return -EFAULT;
+
+		if (wdt_set_timeout(new_timeout))
+		    return -EINVAL;
+
+		wdt_keepalive();
+		/* Fall */
+
+	case WDIOC_GETTIMEOUT:
+		return put_user(timeout, uarg.i);
+
+	}
+}
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code==SYS_DOWN || code==SYS_HALT)
+		wdt_stop();
+	return NOTIFY_DONE;
+}
+
+static struct file_operations wdt_fops=
+{
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= wdt_write,
+	.ioctl		= wdt_ioctl,
+	.open		= wdt_open,
+	.release	= wdt_release,
+};
+
+static struct miscdevice wdt_miscdev=
+{
+	.minor		= WATCHDOG_MINOR,
+	.name		= "watchdog",
+	.fops		= &wdt_fops,
+};
+
+static struct notifier_block wdt_notifier = {
+	.notifier_call = wdt_notify_sys,
+};
+
+static int __init w83977f_wdt_init(void)
+{
+	int rc;
+
+        printk(KERN_INFO PFX DRIVER_VERSION);
+
+	spin_lock_init(&spinlock);
+
+	/*
+	 * Check that the timeout value is within it's range ; 
+	 * if not reset to the default
+	 */
+	if (wdt_set_timeout(timeout)) {
+		wdt_set_timeout(DEFAULT_TIMEOUT);
+		printk(KERN_INFO PFX "timeout value must be 15<=timeout<=7635, using %d\n",
+			DEFAULT_TIMEOUT);
+	}
+
+	if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME))
+	{
+		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
+			IO_INDEX_PORT);
+		rc = -EIO;
+		goto err_out;
+	}
+
+	rc = misc_register(&wdt_miscdev);
+	if (rc)
+	{
+		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+			wdt_miscdev.minor, rc);
+		goto err_out_region;
+	}
+
+	rc = register_reboot_notifier(&wdt_notifier);
+	if (rc)
+	{
+		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
+			rc);
+		goto err_out_miscdev;
+	}
+
+	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
+		timeout, nowayout, testmode);
+
+	return 0;
+
+err_out_miscdev:
+	misc_deregister(&wdt_miscdev);
+err_out_region:
+	release_region(IO_INDEX_PORT,2);
+err_out:
+	return rc;
+}
+
+static void __exit w83977f_wdt_exit(void)
+{
+	wdt_stop();
+	misc_deregister(&wdt_miscdev);
+	unregister_reboot_notifier(&wdt_notifier);
+	release_region(IO_INDEX_PORT,2);
+}
+
+module_init(w83977f_wdt_init);
+module_exit(w83977f_wdt_exit);
+
+MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
+MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);