[WATCHDOG] Merge sma cpu5 watchdog driver.

By Heiko Ronsdorf, has been around linux-kernel a few days, and has
been through some rounds of cleanup.

drivers/char/watchdog/Kconfig

@@ -354,4 +354,14 @@ config WAFER_WDT
 	  Documentation/modules.txt. The module will be called
 	  wafer5823wdt.o
 
+config CPU5_WDT
+	tristate "SMA CPU5 Watchdog"
+	depends on WATCHDOG
+	---help---
+	  TBD.
+	  This driver is also available as a module ( = code which can be
+	  inserted in and removed from the running kernel whenever you want).
+	  The module is called cpu5wdt.o.  If you want to compile it as a
+	  module, say M here and read <file:Documentation/modules.txt>.
+
 endmenu

drivers/char/watchdog/Makefile

@@ -29,3 +29,4 @@ obj-$(CONFIG_SC520_WDT) += sc520_wdt.o
 obj-$(CONFIG_ALIM7101_WDT) += alim7101_wdt.o
 obj-$(CONFIG_SC1200_WDT) += sc1200wdt.o
 obj-$(CONFIG_WAFER_WDT) += wafer5823wdt.o
+obj-$(CONFIG_CPU5_WDT) += cpu5wdt.o

drivers/char/watchdog/cpu5wdt.c

+/*
+ * sma cpu5 watchdog driver
+ *
+ * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include <linux/watchdog.h>
+
+/* adjustable parameters */
+
+static int verbose = 0;
+static int port = 0x91;
+static volatile int ticks = 10000;
+
+#define PFX			"cpu5wdt: "
+
+#define CPU5WDT_EXTENT          0x0A
+
+#define CPU5WDT_STATUS_REG      0x00
+#define CPU5WDT_TIME_A_REG      0x02
+#define CPU5WDT_TIME_B_REG      0x03
+#define CPU5WDT_MODE_REG        0x04
+#define CPU5WDT_TRIGGER_REG     0x07
+#define CPU5WDT_ENABLE_REG      0x08
+#define CPU5WDT_RESET_REG       0x09
+
+#define CPU5WDT_INTERVAL	(HZ/10+1)
+
+/* some device data */
+
+static struct {
+	struct semaphore stop;
+	volatile int running;
+	struct timer_list timer;
+	volatile int queue;
+	int default_ticks;
+	int min_ticks;
+	unsigned long inuse;
+} cpu5wdt_device;
+
+/* generic helper functions */
+
+static void cpu5wdt_trigger(unsigned long unused)
+{
+	if ( verbose > 2 )
+		printk(KERN_DEBUG PFX "trigger at %i ticks\n", ticks);
+
+	if( cpu5wdt_device.running )
+		ticks--;
+
+	/* keep watchdog alive */
+	outb(1, port + CPU5WDT_TRIGGER_REG);
+
+	/* requeue?? */
+	if( cpu5wdt_device.queue && ticks ) {
+		cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL;
+		add_timer(&cpu5wdt_device.timer);
+	}
+	else {
+		/* ticks doesn't matter anyway */
+		up(&cpu5wdt_device.stop);
+	}
+
+}
+
+static void cpu5wdt_reset(void)
+{
+	if ( ticks < cpu5wdt_device.min_ticks )
+		cpu5wdt_device.min_ticks = ticks;
+
+	ticks = cpu5wdt_device.default_ticks;
+
+	if ( verbose )
+		printk(KERN_DEBUG PFX "reset (%i ticks)\n", (int) ticks);
+
+}
+
+static void cpu5wdt_start(void)
+{
+	if ( !cpu5wdt_device.queue ) {
+		cpu5wdt_device.queue = 1;
+		outb(0, port + CPU5WDT_TIME_A_REG);  
+		outb(0, port + CPU5WDT_TIME_B_REG);  
+		outb(1, port + CPU5WDT_MODE_REG);
+		outb(0, port + CPU5WDT_RESET_REG);
+		outb(0, port + CPU5WDT_ENABLE_REG);
+		cpu5wdt_device.timer.expires = jiffies + CPU5WDT_INTERVAL;
+		add_timer(&cpu5wdt_device.timer);
+	}
+	/* if process dies, counter is not decremented */
+	cpu5wdt_device.running++;
+}
+
+static int cpu5wdt_stop(void)
+{
+	if ( cpu5wdt_device.running )
+		cpu5wdt_device.running = 0;
+
+	ticks = cpu5wdt_device.default_ticks;
+
+	if ( verbose )
+		printk(KERN_CRIT PFX "stop not possible\n");
+
+	return -EIO;
+}
+
+/* filesystem operations */
+
+static int cpu5wdt_open(struct inode *inode, struct file *file)
+{
+	switch(minor(inode->i_rdev)) {
+		case WATCHDOG_MINOR:
+			if ( test_and_set_bit(0, &cpu5wdt_device.inuse) )
+				return -EBUSY;
+			break;
+		default:
+			return -ENODEV;
+	}
+	return 0;
+
+}
+
+static int cpu5wdt_release(struct inode *inode, struct file *file)
+{
+	if(minor(inode->i_rdev)==WATCHDOG_MINOR) {
+		clear_bit(0, &cpu5wdt_device.inuse);
+	}
+	return 0;
+}
+
+static int cpu5wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+	unsigned int value;
+	static struct watchdog_info ident =
+	{
+		.options = WDIOF_CARDRESET,
+		.identity = "CPU5 WDT"
+	};
+  
+	switch(cmd) {
+		case WDIOC_KEEPALIVE:
+			cpu5wdt_reset();
+			break;
+		case WDIOC_GETSTATUS:    
+			value = inb(port + CPU5WDT_STATUS_REG); 
+			value = (value >> 2) & 1;
+			if ( copy_to_user((int *)arg, (int *)&value, sizeof(int)) )
+				return -EFAULT;
+			break;
+		case WDIOC_GETSUPPORT:
+			if ( copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)) )
+				return -EFAULT;
+			break;
+		case WDIOC_SETOPTIONS:
+			if ( copy_from_user(&value, (int *)arg, sizeof(int)) )
+				return -EFAULT;
+			switch(value) {
+				case WDIOS_ENABLECARD:
+					cpu5wdt_start();
+					break;
+				case WDIOS_DISABLECARD:
+					return cpu5wdt_stop();
+				default:
+					return -EINVAL;
+			}
+			break;
+		default:
+    			return -EINVAL;
+	}
+	return 0;
+}
+
+static ssize_t cpu5wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
+{
+	if ( !count )
+		return -EIO;
+	
+	cpu5wdt_reset();
+	return count;
+
+}
+
+static struct file_operations cpu5wdt_fops = {
+	.owner		= THIS_MODULE,
+	.ioctl		= cpu5wdt_ioctl,
+	.open		= cpu5wdt_open,
+	.write		= cpu5wdt_write,
+	.release	= cpu5wdt_release,
+};
+
+static struct miscdevice cpu5wdt_misc = {
+	.minor	= WATCHDOG_MINOR,
+	.name	= "watchdog",
+	.fops	= &cpu5wdt_fops
+};
+
+/* init/exit function */
+
+static int __devinit cpu5wdt_init(void)
+{
+	unsigned int val;
+	int err;
+
+	if ( verbose )
+		printk(KERN_DEBUG PFX "port=0x%x, verbose=%i\n", port, verbose);
+
+	if ( (err = misc_register(&cpu5wdt_misc)) < 0 ) {
+		printk(KERN_ERR PFX "misc_register failed\n");
+		goto no_misc;
+	}
+
+	if ( !request_region(port, CPU5WDT_EXTENT, PFX) ) {
+		printk(KERN_ERR PFX "request_region failed\n");
+		err = -EBUSY;
+		goto no_port;
+	}
+
+	/* watchdog reboot? */
+	val = inb(port + CPU5WDT_STATUS_REG); 
+	val = (val >> 2) & 1;
+	if ( !val )
+		printk(KERN_INFO PFX "sorry, was my fault\n");
+
+	init_MUTEX_LOCKED(&cpu5wdt_device.stop);
+	cpu5wdt_device.queue = 0;
+	cpu5wdt_device.min_ticks = ticks;
+
+	clear_bit(0, &cpu5wdt_device.inuse);
+
+	init_timer(&cpu5wdt_device.timer);
+	cpu5wdt_device.timer.function = cpu5wdt_trigger;
+	cpu5wdt_device.timer.data = 0;
+
+	cpu5wdt_device.default_ticks = ticks;
+
+	printk(KERN_INFO PFX "init success\n");
+
+	return 0;
+
+no_port:
+	misc_deregister(&cpu5wdt_misc);
+no_misc:
+	return err;
+}
+
+static int __devinit cpu5wdt_init_module(void)
+{
+	return cpu5wdt_init();
+}
+
+static void __devexit cpu5wdt_exit(void)
+{
+	if ( cpu5wdt_device.queue ) {
+		cpu5wdt_device.queue = 0;
+		down(&cpu5wdt_device.stop);
+	}
+
+	misc_deregister(&cpu5wdt_misc);
+
+	release_region(port, CPU5WDT_EXTENT);
+
+}
+
+static void __devexit cpu5wdt_exit_module(void)
+{
+	cpu5wdt_exit();
+}
+
+/* module entry points */
+
+module_init(cpu5wdt_init_module);
+module_exit(cpu5wdt_exit_module);
+
+MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
+MODULE_DESCRIPTION("sma cpu5 watchdog driver");
+MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
+MODULE_LICENSE("GPL");
+
+MODULE_PARM(port, "i");
+MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
+
+MODULE_PARM(verbose, "i");
+MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
+
+MODULE_PARM(ticks, "i");
+MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
+
+EXPORT_NO_SYMBOLS;