patch-2.4.3 linux/drivers/sbus/char/riowatchdog.c

• Lines: 276
• Date: Sun Mar 25 18:14:20 2001
• Orig file: v2.4.2/linux/drivers/sbus/char/riowatchdog.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.2/linux/drivers/sbus/char/riowatchdog.c linux/drivers/sbus/char/riowatchdog.c
@@ -0,0 +1,275 @@
+/* $Id: riowatchdog.c,v 1.1 2001/03/24 06:04:24 davem Exp $
+ * riowatchdog.c - driver for hw watchdog inside Super I/O of RIO
+ *
+ * Copyright (C) 2001 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+
+#include <asm/io.h>
+#include <asm/ebus.h>
+#include <asm/bbc.h>
+#include <asm/oplib.h>
+#include <asm/uaccess.h>
+
+#include <asm/watchdog.h>
+
+/* RIO uses the NatSemi Super I/O power management logical device
+ * as its' watchdog.
+ *
+ * When the watchdog triggers, it asserts a line to the BBC (Boot Bus
+ * Controller) of the machine.  The BBC can be configured to treat the
+ * assertion of this signal in different ways.  It can trigger an XIR
+ * (external CPU reset) to all the processors or it can trigger a true
+ * power-on reset which triggers the RST signal of all devices in the machine.
+ *
+ * The only Super I/O device register we care about is at index
+ * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255).
+ * If set to zero, this disables the watchdog.  When set, the system
+ * must periodically (before watchdog expires) clear (set to zero) and
+ * re-set the watchdog else it will trigger.
+ *
+ * There are two other indexed watchdog registers inside this Super I/O
+ * logical device, but they are unused.  The first, at index 0x06 is
+ * the watchdog control and can be used to make the watchdog timer re-set
+ * when the PS/2 mouse or serial lines show activity.  The second, at
+ * index 0x07 is merely a sampling of the line from the watchdog to the
+ * BBC.
+ *
+ * The watchdog device generates no interrupts.
+ */
+
+MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
+MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
+MODULE_SUPPORTED_DEVICE("watchdog");
+
+#define RIOWD_NAME	"pmc"
+#define RIOWD_MINOR	215
+
+static spinlock_t riowd_lock = SPIN_LOCK_UNLOCKED;
+
+static void *riowd_regs;
+#define WDTO_INDEX	0x05
+
+static int riowd_timeout = 1;		/* in minutes */
+static int riowd_xir = 1;		/* watchdog generates XIR? */
+MODULE_PARM(riowd_timeout,"i");
+MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes");
+MODULE_PARM(riowd_xir,"i");
+MODULE_PARM_DESC(riowd_xir, "Watchdog generates XIR reset if non-zero");
+
+#if 0 /* Currently unused. */
+static u8 riowd_readreg(int index)
+{
+	unsigned long flags;
+	u8 ret;
+
+	spin_lock_irqsave(&riowd_lock, flags);
+	writeb(index, riowd_regs + 0);
+	ret = readb(riowd_regs + 1);
+	spin_unlock_irqrestore(&riowd_lock, flags);
+
+	return ret;
+}
+#endif
+
+static void riowd_writereg(u8 val, int index)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&riowd_lock, flags);
+	writeb(index, riowd_regs + 0);
+	writeb(val, riowd_regs + 1);
+	spin_unlock_irqrestore(&riowd_lock, flags);
+}
+
+static void riowd_pingtimer(void)
+{
+	riowd_writereg(riowd_timeout, WDTO_INDEX);
+}
+
+static void riowd_stoptimer(void)
+{
+	riowd_writereg(0, WDTO_INDEX);
+}
+
+static void riowd_starttimer(void)
+{
+	riowd_writereg(riowd_timeout, WDTO_INDEX);
+}
+
+static int riowd_open(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+static int riowd_release(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+static int riowd_ioctl(struct inode *inode, struct file *filp,
+		       unsigned int cmd, unsigned long arg)
+{
+	static struct watchdog_info info = { 0, 0, "Natl. Semiconductor PC97317" };
+	unsigned int options;
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user((struct watchdog_info *) arg, &info, sizeof(info)))
+			return -EFAULT;
+		break;
+
+	case WDIOC_GETSTATUS:
+	case WDIOC_GETBOOTSTATUS:
+		if (put_user(0, (int *) arg))
+			return -EFAULT;
+		break;
+
+	case WDIOC_KEEPALIVE:
+		riowd_pingtimer();
+		break;
+
+	case WDIOC_SETOPTIONS:
+		if (copy_from_user(&options, (void *) arg, sizeof(options)))
+			return -EFAULT;
+
+		if (options & WDIOS_DISABLECARD)
+			riowd_stoptimer();
+		else if (options & WDIOS_ENABLECARD)
+			riowd_starttimer();
+		else
+			return -EINVAL;
+
+		break;
+
+	default:
+		return -EINVAL;
+	};
+
+	return 0;
+}
+
+static ssize_t riowd_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
+{
+	if (ppos != &file->f_pos)
+		return -ESPIPE;
+
+	if (count) {
+		riowd_pingtimer();
+		return 1;
+	}
+
+	return 0;
+}
+
+static ssize_t riowd_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
+{
+	return -EINVAL;
+}
+
+static struct file_operations riowd_fops = {
+	owner:		THIS_MODULE,
+	ioctl:		riowd_ioctl,
+	open:		riowd_open,
+	write:		riowd_write,
+	read:		riowd_read,
+	release:	riowd_release,
+};
+
+static struct miscdevice riowd_miscdev = { RIOWD_MINOR, RIOWD_NAME, &riowd_fops };
+
+static int __init riowd_bbc_init(void)
+{
+	struct 	linux_ebus *ebus = NULL;
+	struct 	linux_ebus_device *edev = NULL;
+	void *bbc_regs;
+	u8 val;
+
+	for_each_ebus(ebus) {
+		for_each_ebusdev(edev, ebus) {
+			if (!strcmp(edev->prom_name, "bbc"))
+				goto found_bbc;
+		}
+	}
+
+found_bbc:
+	if (!edev)
+		return -ENODEV;
+	bbc_regs = ioremap(edev->resource[0].start, BBC_REGS_SIZE);
+	if (!bbc_regs)
+		return -ENODEV;
+
+	val = readb(bbc_regs + BBC_WDACTION);
+	if (riowd_xir != 0)
+		val &= ~BBC_WDACTION_RST;
+	else
+		val |= BBC_WDACTION_RST;
+	writeb(val, bbc_regs + BBC_WDACTION);
+
+	iounmap(bbc_regs);
+	return 0;
+}
+
+static int __init riowd_init(void)
+{
+	struct 	linux_ebus *ebus = NULL;
+	struct 	linux_ebus_device *edev = NULL;
+
+	for_each_ebus(ebus) {
+		for_each_ebusdev(edev, ebus) {
+			if (!strcmp(edev->prom_name, RIOWD_NAME))
+				goto ebus_done;
+		}
+	}
+
+ebus_done:
+	if (!edev)
+		goto fail;
+
+	riowd_regs = ioremap(edev->resource[0].start, 2);
+	if (riowd_regs == NULL) {
+		printk(KERN_ERR "pmc: Cannot map registers.\n");
+		return -ENODEV;
+	}
+
+	if (riowd_bbc_init()) {
+		printk(KERN_ERR "pmc: Failure initializing BBC config.\n");
+		goto fail;
+	}
+
+	if (misc_register(&riowd_miscdev)) {
+		printk(KERN_ERR "pmc: Cannot register watchdog misc device.\n");
+		goto fail;
+	}
+
+	printk(KERN_INFO "pmc: Hardware watchdog [%i minutes, %s reset], "
+	       "regs at %p\n",
+	       riowd_timeout, (riowd_xir ? "XIR" : "POR"),
+	       riowd_regs);
+
+	return 0;
+
+fail:
+	if (riowd_regs) {
+		iounmap(riowd_regs);
+		riowd_regs = NULL;
+	}
+	return -ENODEV;
+}
+
+static void __exit riowd_cleanup(void)
+{
+	misc_deregister(&riowd_miscdev);
+	iounmap(riowd_regs);
+	riowd_regs = NULL;
+}
+
+module_init(riowd_init);
+module_exit(riowd_cleanup);