pcwd.c

linux-2.6.15.6

	case WDIOC_SETTIMEOUT:
		if (get_user(new_heartbeat, argp))
			return -EFAULT;

		if (pcwd_set_heartbeat(new_heartbeat))
			return -EINVAL;

		pcwd_keepalive();
		/* Fall */

	case WDIOC_GETTIMEOUT:
		return put_user(heartbeat, argp);
	}

	return 0;
}

static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
			  loff_t *ppos)
{
	if (len) {
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		pcwd_keepalive();
	}
	return len;
}

static int pcwd_open(struct inode *inode, struct file *file)
{
	if (!atomic_dec_and_test(&open_allowed) ) {
		atomic_inc( &open_allowed );
		return -EBUSY;
	}

	if (nowayout)
		__module_get(THIS_MODULE);

	/* Activate */
	pcwd_start();
	pcwd_keepalive();
	return nonseekable_open(inode, file);
}

static int pcwd_close(struct inode *inode, struct file *file)
{
	if (expect_close == 42) {
		pcwd_stop();
	} else {
		printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
		pcwd_keepalive();
	}
	expect_close = 0;
	atomic_inc( &open_allowed );
	return 0;
}

/*
 *	/dev/temperature handling
 */

static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
			 loff_t *ppos)
{
	int temperature;

	if (pcwd_get_temperature(&temperature))
		return -EFAULT;

	if (copy_to_user(buf, &temperature, 1))
		return -EFAULT;

	return 1;
}

static int pcwd_temp_open(struct inode *inode, struct file *file)
{
	if (!supports_temp)
		return -ENODEV;

	return nonseekable_open(inode, file);
}

static int pcwd_temp_close(struct inode *inode, struct file *file)
{
	return 0;
}

/*
 *	Notify system
 */

static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
{
	if (code==SYS_DOWN || code==SYS_HALT) {
		/* Turn the WDT off */
		pcwd_stop();
	}

	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static struct file_operations pcwd_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= pcwd_write,
	.ioctl		= pcwd_ioctl,
	.open		= pcwd_open,
	.release	= pcwd_close,
};

static struct miscdevice pcwd_miscdev = {
	.minor =	WATCHDOG_MINOR,
	.name =		"watchdog",
	.fops =		&pcwd_fops,
};

static struct file_operations pcwd_temp_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= pcwd_temp_read,
	.open		= pcwd_temp_open,
	.release	= pcwd_temp_close,
};

static struct miscdevice temp_miscdev = {
	.minor =	TEMP_MINOR,
	.name =		"temperature",
	.fops =		&pcwd_temp_fops,
};

static struct notifier_block pcwd_notifier = {
	.notifier_call =	pcwd_notify_sys,
};

/*
 *	Init & exit routines
 */

static inline void get_support(void)
{
	if (inb(current_readport) != 0xF0)
		supports_temp = 1;
}

static inline int get_revision(void)
{
	int r = PCWD_REVISION_C;

	spin_lock(&io_lock);
	/* REV A cards use only 2 io ports; test
	 * presumes a floating bus reads as 0xff. */
	if ((inb(current_readport + 2) == 0xFF) ||
	    (inb(current_readport + 3) == 0xFF))
		r=PCWD_REVISION_A;
	spin_unlock(&io_lock);

	return r;
}

static inline char *get_firmware(void)
{
	int one, ten, hund, minor;
	char *ret;

	ret = kmalloc(6, GFP_KERNEL);
	if(ret == NULL)
		return NULL;

	if (set_command_mode()) {
		one = send_isa_command(CMD_ISA_VERSION_INTEGER);
		ten = send_isa_command(CMD_ISA_VERSION_TENTH);
		hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
		minor = send_isa_command(CMD_ISA_VERSION_MINOR);
		sprintf(ret, "%c.%c%c%c", one, ten, hund, minor);
	}
	else
		sprintf(ret, "ERROR");

	unset_command_mode();
	return(ret);
}

static inline int get_option_switches(void)
{
	int rv=0;

	if (set_command_mode()) {
		/* Get switch settings */
		rv = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
	}

	unset_command_mode();
	return(rv);
}

static int __devinit pcwatchdog_init(int base_addr)
{
	int ret;
	char *firmware;
	int option_switches;

	cards_found++;
	if (cards_found == 1)
		printk(KERN_INFO PFX "v%s Ken Hollis ([e-mail])\n", WD_VER);

	if (cards_found > 1) {
		printk(KERN_ERR PFX "This driver only supports 1 device\n");
		return -ENODEV;
	}

	if (base_addr == 0x0000) {
		printk(KERN_ERR PFX "No I/O-Address for card detected\n");
		return -ENODEV;
	}
	current_readport = base_addr;

	/* Check card's revision */
	revision = get_revision();

	if (!request_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
			current_readport);
		current_readport = 0x0000;
		return -EIO;
	}

	/* Initial variables */
	supports_temp = 0;
	temp_panic = 0;
	initial_status = 0x0000;

	/* get the boot_status */
	pcwd_get_status(&initial_status);

	/* clear the "card caused reboot" flag */
	pcwd_clear_status();

	init_timer(&timer);
	timer.function = pcwd_timer_ping;
	timer.data = 0;

	/*  Disable the board  */
	pcwd_stop();

	/*  Check whether or not the card supports the temperature device */
	get_support();

	/* Get some extra info from the hardware (in command/debug/diag mode) */
	if (revision == PCWD_REVISION_A)
		printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", current_readport);
	else if (revision == PCWD_REVISION_C) {
		firmware = get_firmware();
		printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
			current_readport, firmware);
		kfree(firmware);
		option_switches = get_option_switches();
		printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
			option_switches,
			((option_switches & 0x10) ? "ON" : "OFF"),
			((option_switches & 0x08) ? "ON" : "OFF"));

		/* Reprogram internal heartbeat to 2 seconds */
		if (set_command_mode()) {
			send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
			unset_command_mode();
		}
	} else {
		/* Should NEVER happen, unless get_revision() fails. */
		printk(KERN_INFO PFX "Unable to get revision\n");
		release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
		current_readport = 0x0000;
		return -1;
	}

	if (supports_temp)
		printk(KERN_INFO PFX "Temperature Option Detected\n");

	if (initial_status & WDIOF_CARDRESET)
		printk(KERN_INFO PFX "Previous reboot was caused by the card\n");

	if (initial_status & WDIOF_OVERHEAT) {
		printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
		printk(KERN_EMERG PFX "CPU Overheat\n");
	}

	if (initial_status == 0)
		printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");

	/* Check that the heartbeat value is within it's range ; if not reset to the default */
        if (pcwd_set_heartbeat(heartbeat)) {
                pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
                printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
                        WATCHDOG_HEARTBEAT);
	}

	ret = register_reboot_notifier(&pcwd_notifier);
	if (ret) {
		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
			ret);
		release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
		current_readport = 0x0000;
		return ret;
	}

	if (supports_temp) {
		ret = misc_register(&temp_miscdev);
		if (ret) {
			printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
				TEMP_MINOR, ret);
			unregister_reboot_notifier(&pcwd_notifier);
			release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
			current_readport = 0x0000;
			return ret;
		}
	}

	ret = misc_register(&pcwd_miscdev);
	if (ret) {
		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		if (supports_temp)
			misc_deregister(&temp_miscdev);
		unregister_reboot_notifier(&pcwd_notifier);
		release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
		current_readport = 0x0000;
		return ret;
	}

	printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
		heartbeat, nowayout);

	return 0;
}

static void __devexit pcwatchdog_exit(void)
{
	/*  Disable the board  */
	if (!nowayout)
		pcwd_stop();

	/* Deregister */
	misc_deregister(&pcwd_miscdev);
	if (supports_temp)
		misc_deregister(&temp_miscdev);
	unregister_reboot_notifier(&pcwd_notifier);
	release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
	current_readport = 0x0000;
}

/*
 *  The ISA cards have a heartbeat bit in one of the registers, which
 *  register is card dependent.  The heartbeat bit is monitored, and if
 *  found, is considered proof that a Berkshire card has been found.
 *  The initial rate is once per second at board start up, then twice
 *  per second for normal operation.
 */
static int __init pcwd_checkcard(int base_addr)
{
	int port0, last_port0;	/* Reg 0, in case it's REV A */
	int port1, last_port1;	/* Register 1 for REV C cards */
	int i;
	int retval;

	if (!request_region (base_addr, 4, "PCWD")) {
		printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
		return 0;
	}

	retval = 0;

	port0 = inb_p(base_addr);	/* For REV A boards */
	port1 = inb_p(base_addr + 1);	/* For REV C boards */
	if (port0 != 0xff || port1 != 0xff) {
		/* Not an 'ff' from a floating bus, so must be a card! */
		for (i = 0; i < 4; ++i) {

			msleep(500);

			last_port0 = port0;
			last_port1 = port1;

			port0 = inb_p(base_addr);
			port1 = inb_p(base_addr + 1);

			/* Has either hearbeat bit changed?  */
			if ((port0 ^ last_port0) & WD_HRTBT ||
			    (port1 ^ last_port1) & WD_REVC_HRBT) {
				retval = 1;
				break;
			}
		}
	}
	release_region (base_addr, 4);

	return retval;
}

/*
 * These are the auto-probe addresses available.
 *
 * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 * Revision A has an address range of 2 addresses, while Revision C has 4.
 */
static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };

static int __init pcwd_init_module(void)
{
	int i, found = 0;

	spin_lock_init(&io_lock);

	for (i = 0; pcwd_ioports[i] != 0; i++) {
		if (pcwd_checkcard(pcwd_ioports[i])) {
			if (!(pcwatchdog_init(pcwd_ioports[i])))
				found++;
		}
	}

	if (!found) {
		printk (KERN_INFO PFX "No card detected, or port not available\n");
		return -ENODEV;
	}

	return 0;
}

static void __exit pcwd_cleanup_module(void)
{
	if (current_readport)
		pcwatchdog_exit();
	return;
}

module_init(pcwd_init_module);
module_exit(pcwd_cleanup_module);

MODULE_AUTHOR("Ken Hollis <[e-mail]>");
MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS_MISCDEV(TEMP_MINOR);