patch-2.0.11 linux/drivers/char/pcwd.c

• Lines: 332
• Date: Thu Aug 1 16:12:26 1996
• Orig file: v2.0.10/linux/drivers/char/pcwd.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.0.10/linux/drivers/char/pcwd.c linux/drivers/char/pcwd.c
@@ -0,0 +1,331 @@
+/*
+ * PC Watchdog Driver
+ * by Ken Hollis (khollis@bitgate.com)
+ *
+ * Permission granted from Simon Machell (73244.1270@compuserve.com)
+ * Written for the Linux Kernel, and GPLed by Ken Hollis
+ *
+ * 960107	Added request_region routines, modulized the whole thing.
+ * 960108	Fixed end-of-file pointer (Thanks to Dan Hollis), added
+ *		WD_TIMEOUT define.
+ * 960216	Added eof marker on the file, and changed verbose messages.
+ * 960716	Made functional and cosmetic changes to the source for
+ *		inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
+ * 960717	Removed read/seek routines, replaced with ioctl.  Also, added
+ *		check_region command due to Alan's suggestion.
+ */
+
+#include <linux/module.h>
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/tty.h>
+#include <linux/timer.h>
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/string.h>
+#include <linux/malloc.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/pcwd.h>
+
+#include <asm/io.h>
+
+#define WD_VER                  "0.41 (07/17/96)"
+#define	WD_MINOR		130	/* Minor device number */
+
+#define	WD_TIMEOUT		3	/* 1 1/2 seconds for a timeout */
+
+#define WD_TIMERRESET_PORT1     0x270	/* Reset port - first choice */
+#define WD_TIMERRESET_PORT2     0x370	/* Reset port - second choice */
+#define WD_CTLSTAT_PORT1        0x271	/* Control port - first choice */
+#define WD_CTLSTAT_PORT2        0x371	/* Control port - second choice */
+#define	WD_PORT_EXTENT		2	/* Takes up two addresses */
+
+#define WD_WDRST                0x01	/* Previously reset state */
+#define WD_T110                 0x02	/* Temperature overheat sense */
+#define WD_HRTBT                0x04	/* Heartbeat sense */
+#define WD_RLY2                 0x08	/* External relay triggered */
+#define WD_SRLY2                0x80	/* Software external relay triggered */
+
+static int current_ctlport, current_readport;
+static int is_open, is_eof;
+
+int pcwd_checkcard(void)
+{
+	int card_dat, prev_card_dat, found = 0, count = 0, done = 0;
+
+	/* As suggested by Alan Cox */
+	if (check_region(current_ctlport, WD_PORT_EXTENT)) {
+		printk("pcwd: Port 0x%x unavailable.\n", current_ctlport);
+		return 0;
+	}
+
+	card_dat = 0x00;
+	prev_card_dat = 0x00;
+
+	prev_card_dat = inb(current_readport);
+
+	while(count < WD_TIMEOUT) {
+#ifdef	DEBUG
+		printk("pcwd: Run #%d on port 0x%03x\n", count, current_readport);
+#endif
+
+	/* Read the raw card data from the port, and strip off the
+	   first 4 bits */
+
+		card_dat = inb_p(current_readport);
+		card_dat &= 0x000F;
+
+	/* Sleep 1/2 second (or 500000 microseconds :) */
+
+		udelay(500000L);
+		done = 0;
+
+	/* 0x0F usually means that no card data is present, or the card
+	   is not installed on this port.  If 0x0F is present here, it's
+	   normally safe to assume there's no card at that base address. */
+
+		if (card_dat == 0x0F) {
+			count++;
+			done = 1;
+
+#ifdef	DEBUG
+			printk("pcwd: I show nothing on this port.\n");
+#endif
+		}
+
+	/* If there's a heart beat in both instances, then this means we
+	   found our card.  This also means that either the card was
+	   previously reset, or the computer was power-cycled. */
+
+		if ((card_dat & WD_HRTBT) && (prev_card_dat & WD_HRTBT) &&
+			(!done)) {
+			found = 1;
+			done = 1;
+#ifdef	DEBUG
+			printk("pcwd: I show alternate heart beats.  Card detected.\n");
+#endif
+			break;
+		}
+
+	/* If the card data is exactly the same as the previous card data,
+	   it's safe to assume that we should check again.  The manual says
+	   that the heart beat will change every second (or the bit will
+	   toggle), and this can be used to see if the card is there.  If
+	   the card was powered up with a cold boot, then the card will
+	   not start blinking until 2.5 minutes after a reboot, so this
+	   bit will stay at 1. */
+
+		if ((card_dat == prev_card_dat) && (!done)) {
+			count++;
+#ifdef	DEBUG
+			printk("pcwd: The card data is exactly the same (possibility).\n");
+#endif
+			done = 1;
+		}
+
+	/* If the card data is toggling any bits, this means that the heart
+	   beat was detected, or something else about the card is set. */
+
+		if ((card_dat != prev_card_dat) && (!done)) {
+			done = 1;
+			found = 1;
+#ifdef	DEBUG
+			printk("pcwd: I show alternate heart beats.  Card detected.\n");
+#endif
+			break;
+		}
+
+	/* Otherwise something else strange happened. */
+
+		if (!done)
+			count++;
+	}
+
+	return((found) ? 1 : 0);
+}
+
+void pcwd_showprevstate(void)
+{
+	int card_status = 0x0000;
+
+	card_status = inb(current_readport);
+
+	if (card_status & WD_WDRST)
+		printk("pcwd: Previous reboot was caused by the card.\n");
+
+	if (card_status & WD_T110)
+		printk("pcwd: CPU overheat sense\n");
+}
+
+static int pcwd_return_data(void)
+{
+	return(inb(current_readport));
+}
+
+static int pcwd_write(struct inode *inode, struct file *file, const char *data,
+	int len)
+{
+	int wdrst_stat;
+
+	if (!is_open)
+		return -EIO;
+
+#ifdef	DEBUG
+	printk("pcwd: write request\n");
+#endif
+
+	wdrst_stat = inb_p(current_readport);
+	wdrst_stat &= 0x0F;
+
+	wdrst_stat |= WD_WDRST;
+
+	outb_p(wdrst_stat, current_ctlport);
+
+	return(1);
+}
+
+static int pcwd_ioctl(struct tty_struct *tty, struct file *file,
+	unsigned int cmd, unsigned long arg)
+{
+	int i, cdat, rv;
+
+	switch(cmd) {
+	default:
+		return -ENOIOCTLCMD;
+
+	case PCWD_GETSTAT:
+		i = verify_area(VERIFY_WRITE, (void*) arg, sizeof(int));
+		if (i)
+			return i;
+		else {
+			cdat = pcwd_return_data();
+			rv = 0;
+
+			if (cdat & WD_WDRST)
+				rv |= 0x01;
+
+			if (cdat & WD_T110)
+				rv |= 0x02;
+
+			put_user(rv, (int *) arg);
+			return 0;
+		}
+		break;
+
+	case PCWD_PING:
+		pcwd_write(NULL, NULL, NULL, 1);	/* Is this legal? */
+		break;
+	}
+
+	return 0;
+}
+
+static int pcwd_open(struct inode *ino, struct file *filep)
+{
+#ifdef	DEBUG
+	printk("pcwd: open request\n");
+#endif
+
+	MOD_INC_USE_COUNT;
+	is_eof = 0;
+	return(0);
+}
+
+static void pcwd_close(struct inode *ino, struct file *filep)
+{
+#ifdef	DEBUG
+	printk("pcwd: close request\n");
+#endif
+
+	MOD_DEC_USE_COUNT;
+}
+
+struct file_operations pcwd_fops = {
+	NULL,		/* Seek */
+	NULL,		/* Read */
+	pcwd_write,	/* Write */
+	NULL,		/* Readdir */
+	NULL,		/* Select */
+	pcwd_ioctl,	/* IOctl */
+	NULL,		/* MMAP */
+	pcwd_open,	/* Open */
+	pcwd_close,	/* Close */
+	NULL
+};
+
+static struct miscdevice pcwd_miscdev = {
+	WD_MINOR,
+	"pcwatchdog",
+	&pcwd_fops
+};
+ 
+#ifdef	MODULE
+int init_module(void)
+#else
+int pcwatchdog_init(void)
+#endif
+{
+#ifdef	DEBUG
+	printk("pcwd: Success.\n");
+#endif
+	printk("pcwd: v%s Ken Hollis (khollis@bitgate.com)\n", WD_VER);
+
+#ifdef	DEBUG
+	printk("pcwd: About to perform card autosense loop.\n");
+#endif
+
+	is_eof = 0;
+	is_open = 0;
+
+	current_ctlport = WD_TIMERRESET_PORT1;
+	current_readport = WD_CTLSTAT_PORT1;
+
+	if (!pcwd_checkcard()) {
+#ifdef	DEBUG
+		printk("pcwd: Trying port 0x370.\n");
+#endif
+
+		current_ctlport = WD_TIMERRESET_PORT2;
+		current_readport = WD_CTLSTAT_PORT2;
+
+		if (!pcwd_checkcard()) {
+			printk("pcwd: No card detected.\n");
+			return(-EIO);
+		} else
+			printk("pcwd: Port available at 0x370.\n");
+	} else
+		printk("pcwd: Port available at 0x270.\n");
+
+	pcwd_showprevstate();
+
+#ifdef	DEBUG
+	printk("pcwd: Requesting region entry\n");
+#endif
+
+	request_region(current_ctlport, WD_PORT_EXTENT, "PCWD (Berkshire)");
+
+#ifdef	DEBUG
+	printk("pcwd: character device creation.\n");
+#endif
+
+	misc_register(&pcwd_miscdev);
+
+	return 0;
+}
+
+#ifdef	MODULE
+void cleanup_module(void)
+{
+	misc_deregister(&pcwd_miscdev);
+	release_region(current_ctlport, 2);
+#ifdef	DEBUG
+	printk("pcwd: Cleanup successful.\n");
+#endif
+}
+#endif