patch-2.4.25 linux-2.4.25/drivers/char/mpc8xx_wdt.c

• Lines: 192
• Date: 2004-02-18 05:36:31.000000000 -0800
• Orig file: linux-2.4.24/drivers/char/mpc8xx_wdt.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.24/drivers/char/mpc8xx_wdt.c linux-2.4.25/drivers/char/mpc8xx_wdt.c
@@ -0,0 +1,191 @@
+/*
+ * mpc8xx_wdt.c - MPC8xx watchdog userspace interface
+ *
+ * Copyright (C) 2002 Florian Schirmer <jolt@tuxbox.org>
+ *
+ * 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/init.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <asm/8xx_immap.h>
+#include <asm/uaccess.h>
+
+extern int m8xx_wdt_get_timeout(void);
+extern void m8xx_wdt_reset(void);
+
+static struct semaphore wdt_sem;
+static int wdt_status;
+
+static struct watchdog_info ident = {
+	.identity = "MPC8xx watchdog",
+	.options = WDIOF_KEEPALIVEPING,
+};
+
+static void
+mpc8xx_wdt_handler_disable(void)
+{
+	volatile immap_t *imap = (volatile immap_t *) IMAP_ADDR;
+
+	imap->im_sit.sit_piscr &= ~(PISCR_PIE | PISCR_PTE);
+
+	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler deactivated\n");
+}
+
+static void
+mpc8xx_wdt_handler_enable(void)
+{
+	volatile immap_t *imap = (volatile immap_t *) IMAP_ADDR;
+
+	imap->im_sit.sit_piscr |= PISCR_PIE | PISCR_PTE;
+
+	printk(KERN_NOTICE "mpc8xx_wdt: keep-alive handler activated\n");
+}
+
+static int
+mpc8xx_wdt_open(struct inode *inode, struct file *file)
+{
+	switch (MINOR(inode->i_rdev)) {
+	case WATCHDOG_MINOR:
+		if (down_trylock(&wdt_sem))
+			return -EBUSY;
+
+		m8xx_wdt_reset();
+		mpc8xx_wdt_handler_disable();
+		break;
+
+	default:
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int
+mpc8xx_wdt_release(struct inode *inode, struct file *file)
+{
+	m8xx_wdt_reset();
+
+#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
+	mpc8xx_wdt_handler_enable();
+#endif
+
+	up(&wdt_sem);
+
+	return 0;
+}
+
+static ssize_t
+mpc8xx_wdt_write(struct file *file, const char *data, size_t len, loff_t * ppos)
+{
+	/* Can't seek (pwrite) on this device */
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	if (!len)
+		return 0;
+
+	m8xx_wdt_reset();
+
+	return 1;
+}
+
+static int
+mpc8xx_wdt_ioctl(struct inode *inode, struct file *file,
+		 unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user((void *) arg, &ident, sizeof (ident)))
+			return -EFAULT;
+		break;
+
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		if (put_user(wdt_status, (int *) arg))
+			return -EFAULT;
+		wdt_status &= ~WDIOF_KEEPALIVEPING;
+		break;
+
+	case WDIOC_KEEPALIVE:
+		m8xx_wdt_reset();
+		wdt_status |= WDIOF_KEEPALIVEPING;
+		break;
+
+	case WDIOC_GETTIMEOUT:
+		{
+			int timeout = m8xx_wdt_get_timeout();
+			if (put_user(timeout, (int *) arg))
+				return -EFAULT;
+			break;
+		}
+
+	default:
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
+static struct file_operations mpc8xx_wdt_fops = {
+	.owner = THIS_MODULE,
+	.write = mpc8xx_wdt_write,
+	.ioctl = mpc8xx_wdt_ioctl,
+	.open = mpc8xx_wdt_open,
+	.release = mpc8xx_wdt_release,
+};
+
+static struct miscdevice mpc8xx_wdt_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name = "watchdog",
+	.fops = &mpc8xx_wdt_fops,
+};
+
+static int __init
+mpc8xx_wdt_init(void)
+{
+	int ret;
+
+	sema_init(&wdt_sem, 1);
+
+	if ((ret = misc_register(&mpc8xx_wdt_miscdev))) {
+		printk(KERN_WARNING
+		       "mpc8xx_wdt: could not register userspace interface\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit
+mpc8xx_wdt_exit(void)
+{
+	misc_deregister(&mpc8xx_wdt_miscdev);
+
+	m8xx_wdt_reset();
+	mpc8xx_wdt_handler_enable();
+}
+
+module_init(mpc8xx_wdt_init);
+module_exit(mpc8xx_wdt_exit);
+
+MODULE_AUTHOR("Florian Schirmer <jolt@tuxbox.org>");
+MODULE_DESCRIPTION("MPC8xx watchdog driver");
+MODULE_LICENSE("GPL");