Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 998 insertions, 0 deletions

diff --git a/drivers/watchdog/pcwd.c b/drivers/watchdog/pcwd.c
new file mode 100644
index 000000000..a793b03a7
--- /dev/null
+++ b/drivers/watchdog/pcwd.c
@@ -0,0 +1,998 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PC Watchdog Driver
+ * by Ken Hollis (khollis@bitgate.com)
+ *
+ * Permission granted from Simon Machell (smachell@berkprod.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.
+ * 960821	Made changes to compile in newer 2.0.x kernels.  Added
+ *		"cold reboot sense" entry.
+ * 960825	Made a few changes to code, deleted some defines and made
+ *		typedefs to replace them.  Made heartbeat reset only available
+ *		via ioctl, and removed the write routine.
+ * 960828	Added new items for PC Watchdog Rev.C card.
+ * 960829	Changed around all of the IOCTLs, added new features,
+ *		added watchdog disable/re-enable routines.  Added firmware
+ *		version reporting.  Added read routine for temperature.
+ *		Removed some extra defines, added an autodetect Revision
+ *		routine.
+ * 961006	Revised some documentation, fixed some cosmetic bugs.  Made
+ *		drivers to panic the system if it's overheating at bootup.
+ * 961118	Changed some verbiage on some of the output, tidied up
+ *		code bits, and added compatibility to 2.1.x.
+ * 970912	Enabled board on open and disable on close.
+ * 971107	Took account of recent VFS changes (broke read).
+ * 971210	Disable board on initialisation in case board already ticking.
+ * 971222	Changed open/close for temperature handling
+ *		Michael Meskes <meskes@debian.org>.
+ * 980112	Used minor numbers from include/linux/miscdevice.h
+ * 990403	Clear reset status after reading control status register in
+ *		pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
+ * 990605	Made changes to code to support Firmware 1.22a, added
+ *		fairly useless proc entry.
+ * 990610	removed said useless proc code for the merge <alan>
+ * 000403	Removed last traces of proc code. <davej>
+ * 011214	Added nowayout module option to override
+ *		CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
+ *		Added timeout module option to override default
+ */
+
+/*
+ *	A bells and whistles driver is available from http://www.pcwd.de/
+ *	More info available at http://www.berkprod.com/ or
+ *	http://www.pcwatchdog.com/
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>	/* For module specific items */
+#include <linux/moduleparam.h>	/* For new moduleparam's */
+#include <linux/types.h>	/* For standard types (like size_t) */
+#include <linux/errno.h>	/* For the -ENODEV/... values */
+#include <linux/kernel.h>	/* For printk/panic/... */
+#include <linux/delay.h>	/* For mdelay function */
+#include <linux/timer.h>	/* For timer related operations */
+#include <linux/jiffies.h>	/* For jiffies stuff */
+#include <linux/miscdevice.h>	/* For struct miscdevice */
+#include <linux/watchdog.h>	/* For the watchdog specific items */
+#include <linux/reboot.h>	/* For kernel_power_off() */
+#include <linux/init.h>		/* For __init/__exit/... */
+#include <linux/fs.h>		/* For file operations */
+#include <linux/isa.h>		/* For isa devices */
+#include <linux/ioport.h>	/* For io-port access */
+#include <linux/spinlock.h>	/* For spin_lock/spin_unlock/... */
+#include <linux/uaccess.h>	/* For copy_to_user/put_user/... */
+#include <linux/io.h>		/* For inb/outb/... */
+
+/* Module and version information */
+#define WATCHDOG_VERSION "1.20"
+#define WATCHDOG_DATE "18 Feb 2007"
+#define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
+#define WATCHDOG_NAME "pcwd"
+#define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
+
+/*
+ * It should be noted that PCWD_REVISION_B was removed because A and B
+ * are essentially the same types of card, with the exception that B
+ * has temperature reporting.  Since I didn't receive a Rev.B card,
+ * the Rev.B card is not supported.  (It's a good thing too, as they
+ * are no longer in production.)
+ */
+#define	PCWD_REVISION_A		1
+#define	PCWD_REVISION_C		2
+
+/*
+ * 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.
+ */
+#define PCWD_ISA_NR_CARDS	3
+static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
+
+/*
+ * These are the defines that describe the control status bits for the
+ * PCI-PC Watchdog card.
+*/
+/* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
+#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 */
+/* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
+#define WD_REVC_WTRP		0x01	/* Watchdog Trip status */
+#define WD_REVC_HRBT		0x02	/* Watchdog Heartbeat */
+#define WD_REVC_TTRP		0x04	/* Temperature Trip status */
+#define WD_REVC_RL2A		0x08	/* Relay 2 activated by
+							on-board processor */
+#define WD_REVC_RL1A		0x10	/* Relay 1 active */
+#define WD_REVC_R2DS		0x40	/* Relay 2 disable */
+#define WD_REVC_RLY2		0x80	/* Relay 2 activated? */
+/* Port 2 : Control Status #2 */
+#define WD_WDIS			0x10	/* Watchdog Disabled */
+#define WD_ENTP			0x20	/* Watchdog Enable Temperature Trip */
+#define WD_SSEL			0x40	/* Watchdog Switch Select
+							(1:SW1 <-> 0:SW2) */
+#define WD_WCMD			0x80	/* Watchdog Command Mode */
+
+/* max. time we give an ISA watchdog card to process a command */
+/* 500ms for each 4 bit response (according to spec.) */
+#define ISA_COMMAND_TIMEOUT     1000
+
+/* Watchdog's internal commands */
+#define CMD_ISA_IDLE			0x00
+#define CMD_ISA_VERSION_INTEGER		0x01
+#define CMD_ISA_VERSION_TENTH		0x02
+#define CMD_ISA_VERSION_HUNDRETH	0x03
+#define CMD_ISA_VERSION_MINOR		0x04
+#define CMD_ISA_SWITCH_SETTINGS		0x05
+#define CMD_ISA_RESET_PC		0x06
+#define CMD_ISA_ARM_0			0x07
+#define CMD_ISA_ARM_30			0x08
+#define CMD_ISA_ARM_60			0x09
+#define CMD_ISA_DELAY_TIME_2SECS	0x0A
+#define CMD_ISA_DELAY_TIME_4SECS	0x0B
+#define CMD_ISA_DELAY_TIME_8SECS	0x0C
+#define CMD_ISA_RESET_RELAYS		0x0D
+
+/* Watchdog's Dip Switch heartbeat values */
+static const int heartbeat_tbl[] = {
+	20,	/* OFF-OFF-OFF	= 20 Sec  */
+	40,	/* OFF-OFF-ON	= 40 Sec  */
+	60,	/* OFF-ON-OFF	=  1 Min  */
+	300,	/* OFF-ON-ON	=  5 Min  */
+	600,	/* ON-OFF-OFF	= 10 Min  */
+	1800,	/* ON-OFF-ON	= 30 Min  */
+	3600,	/* ON-ON-OFF	=  1 Hour */
+	7200,	/* ON-ON-ON	=  2 hour */
+};
+
+/*
+ * We are using an kernel timer to do the pinging of the watchdog
+ * every ~500ms. We try to set the internal heartbeat of the
+ * watchdog to 2 ms.
+ */
+
+#define WDT_INTERVAL (HZ/2+1)
+
+/* We can only use 1 card due to the /dev/watchdog restriction */
+static int cards_found;
+
+/* internal variables */
+static unsigned long open_allowed;
+static char expect_close;
+static int temp_panic;
+
+/* this is private data for each ISA-PC watchdog card */
+static struct {
+	char fw_ver_str[6];		/* The cards firmware version */
+	int revision;			/* The card's revision */
+	int supports_temp;		/* Whether or not the card has
+						a temperature device */
+	int command_mode;		/* Whether or not the card is in
+						command mode */
+	int boot_status;		/* The card's boot status */
+	int io_addr;			/* The cards I/O address */
+	spinlock_t io_lock;		/* the lock for io operations */
+	struct timer_list timer;	/* The timer that pings the watchdog */
+	unsigned long next_heartbeat;	/* the next_heartbeat for the timer */
+} pcwd_private;
+
+/* module parameters */
+#define QUIET	0	/* Default */
+#define VERBOSE	1	/* Verbose */
+#define DEBUG	2	/* print fancy stuff too */
+static int debug = QUIET;
+module_param(debug, int, 0);
+MODULE_PARM_DESC(debug,
+		"Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
+
+/* default heartbeat = delay-time from dip-switches */
+#define WATCHDOG_HEARTBEAT 0
+static int heartbeat = WATCHDOG_HEARTBEAT;
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
+	"(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
+				__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+		"Watchdog cannot be stopped once started (default="
+				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/*
+ *	Internal functions
+ */
+
+static int send_isa_command(int cmd)
+{
+	int i;
+	int control_status;
+	int port0, last_port0;	/* Double read for stabilising */
+
+	if (debug >= DEBUG)
+		pr_debug("sending following data cmd=0x%02x\n", cmd);
+
+	/* The WCMD bit must be 1 and the command is only 4 bits in size */
+	control_status = (cmd & 0x0F) | WD_WCMD;
+	outb_p(control_status, pcwd_private.io_addr + 2);
+	udelay(ISA_COMMAND_TIMEOUT);
+
+	port0 = inb_p(pcwd_private.io_addr);
+	for (i = 0; i < 25; ++i) {
+		last_port0 = port0;
+		port0 = inb_p(pcwd_private.io_addr);
+
+		if (port0 == last_port0)
+			break;	/* Data is stable */
+
+		udelay(250);
+	}
+
+	if (debug >= DEBUG)
+		pr_debug("received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
+			 cmd, port0, last_port0);
+
+	return port0;
+}
+
+static int set_command_mode(void)
+{
+	int i, found = 0, count = 0;
+
+	/* Set the card into command mode */
+	spin_lock(&pcwd_private.io_lock);
+	while ((!found) && (count < 3)) {
+		i = send_isa_command(CMD_ISA_IDLE);
+
+		if (i == 0x00)
+			found = 1;
+		else if (i == 0xF3) {
+			/* Card does not like what we've done to it */
+			outb_p(0x00, pcwd_private.io_addr + 2);
+			udelay(1200);	/* Spec says wait 1ms */
+			outb_p(0x00, pcwd_private.io_addr + 2);
+			udelay(ISA_COMMAND_TIMEOUT);
+		}
+		count++;
+	}
+	spin_unlock(&pcwd_private.io_lock);
+	pcwd_private.command_mode = found;
+
+	if (debug >= DEBUG)
+		pr_debug("command_mode=%d\n", pcwd_private.command_mode);
+
+	return found;
+}
+
+static void unset_command_mode(void)
+{
+	/* Set the card into normal mode */
+	spin_lock(&pcwd_private.io_lock);
+	outb_p(0x00, pcwd_private.io_addr + 2);
+	udelay(ISA_COMMAND_TIMEOUT);
+	spin_unlock(&pcwd_private.io_lock);
+
+	pcwd_private.command_mode = 0;
+
+	if (debug >= DEBUG)
+		pr_debug("command_mode=%d\n", pcwd_private.command_mode);
+}
+
+static inline void pcwd_check_temperature_support(void)
+{
+	if (inb(pcwd_private.io_addr) != 0xF0)
+		pcwd_private.supports_temp = 1;
+}
+
+static inline void pcwd_get_firmware(void)
+{
+	int one, ten, hund, minor;
+
+	strcpy(pcwd_private.fw_ver_str, "ERROR");
+
+	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(pcwd_private.fw_ver_str, "%c.%c%c%c",
+					one, ten, hund, minor);
+	}
+	unset_command_mode();
+
+	return;
+}
+
+static inline int pcwd_get_option_switches(void)
+{
+	int option_switches = 0;
+
+	if (set_command_mode()) {
+		/* Get switch settings */
+		option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
+	}
+
+	unset_command_mode();
+	return option_switches;
+}
+
+static void pcwd_show_card_info(void)
+{
+	int option_switches;
+
+	/* Get some extra info from the hardware (in command/debug/diag mode) */
+	if (pcwd_private.revision == PCWD_REVISION_A)
+		pr_info("ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
+			pcwd_private.io_addr);
+	else if (pcwd_private.revision == PCWD_REVISION_C) {
+		pcwd_get_firmware();
+		pr_info("ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
+			pcwd_private.io_addr, pcwd_private.fw_ver_str);
+		option_switches = pcwd_get_option_switches();
+		pr_info("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();
+		}
+	}
+
+	if (pcwd_private.supports_temp)
+		pr_info("Temperature Option Detected\n");
+
+	if (pcwd_private.boot_status & WDIOF_CARDRESET)
+		pr_info("Previous reboot was caused by the card\n");
+
+	if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
+		pr_emerg("Card senses a CPU Overheat. Panicking!\n");
+		pr_emerg("CPU Overheat\n");
+	}
+
+	if (pcwd_private.boot_status == 0)
+		pr_info("No previous trip detected - Cold boot or reset\n");
+}
+
+static void pcwd_timer_ping(struct timer_list *unused)
+{
+	int wdrst_stat;
+
+	/* If we got a heartbeat pulse within the WDT_INTERVAL
+	 * we agree to ping the WDT */
+	if (time_before(jiffies, pcwd_private.next_heartbeat)) {
+		/* Ping the watchdog */
+		spin_lock(&pcwd_private.io_lock);
+		if (pcwd_private.revision == PCWD_REVISION_A) {
+			/*  Rev A cards are reset by setting the
+			    WD_WDRST bit in register 1 */
+			wdrst_stat = inb_p(pcwd_private.io_addr);
+			wdrst_stat &= 0x0F;
+			wdrst_stat |= WD_WDRST;
+
+			outb_p(wdrst_stat, pcwd_private.io_addr + 1);
+		} else {
+			/* Re-trigger watchdog by writing to port 0 */
+			outb_p(0x00, pcwd_private.io_addr);
+		}
+
+		/* Re-set the timer interval */
+		mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
+
+		spin_unlock(&pcwd_private.io_lock);
+	} else {
+		pr_warn("Heartbeat lost! Will not ping the watchdog\n");
+	}
+}
+
+static int pcwd_start(void)
+{
+	int stat_reg;
+
+	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
+
+	/* Start the timer */
+	mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
+
+	/* Enable the port */
+	if (pcwd_private.revision == PCWD_REVISION_C) {
+		spin_lock(&pcwd_private.io_lock);
+		outb_p(0x00, pcwd_private.io_addr + 3);
+		udelay(ISA_COMMAND_TIMEOUT);
+		stat_reg = inb_p(pcwd_private.io_addr + 2);
+		spin_unlock(&pcwd_private.io_lock);
+		if (stat_reg & WD_WDIS) {
+			pr_info("Could not start watchdog\n");
+			return -EIO;
+		}
+	}
+
+	if (debug >= VERBOSE)
+		pr_debug("Watchdog started\n");
+
+	return 0;
+}
+
+static int pcwd_stop(void)
+{
+	int stat_reg;
+
+	/* Stop the timer */
+	del_timer(&pcwd_private.timer);
+
+	/*  Disable the board  */
+	if (pcwd_private.revision == PCWD_REVISION_C) {
+		spin_lock(&pcwd_private.io_lock);
+		outb_p(0xA5, pcwd_private.io_addr + 3);
+		udelay(ISA_COMMAND_TIMEOUT);
+		outb_p(0xA5, pcwd_private.io_addr + 3);
+		udelay(ISA_COMMAND_TIMEOUT);
+		stat_reg = inb_p(pcwd_private.io_addr + 2);
+		spin_unlock(&pcwd_private.io_lock);
+		if ((stat_reg & WD_WDIS) == 0) {
+			pr_info("Could not stop watchdog\n");
+			return -EIO;
+		}
+	}
+
+	if (debug >= VERBOSE)
+		pr_debug("Watchdog stopped\n");
+
+	return 0;
+}
+
+static int pcwd_keepalive(void)
+{
+	/* user land ping */
+	pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
+
+	if (debug >= DEBUG)
+		pr_debug("Watchdog keepalive signal send\n");
+
+	return 0;
+}
+
+static int pcwd_set_heartbeat(int t)
+{
+	if (t < 2 || t > 7200) /* arbitrary upper limit */
+		return -EINVAL;
+
+	heartbeat = t;
+
+	if (debug >= VERBOSE)
+		pr_debug("New heartbeat: %d\n", heartbeat);
+
+	return 0;
+}
+
+static int pcwd_get_status(int *status)
+{
+	int control_status;
+
+	*status = 0;
+	spin_lock(&pcwd_private.io_lock);
+	if (pcwd_private.revision == PCWD_REVISION_A)
+		/* Rev A cards return status information from
+		 * the base register, which is used for the
+		 * temperature in other cards. */
+		control_status = inb(pcwd_private.io_addr);
+	else {
+		/* Rev C cards return card status in the base
+		 * address + 1 register. And use different bits
+		 * to indicate a card initiated reset, and an
+		 * over-temperature condition. And the reboot
+		 * status can be reset. */
+		control_status = inb(pcwd_private.io_addr + 1);
+	}
+	spin_unlock(&pcwd_private.io_lock);
+
+	if (pcwd_private.revision == PCWD_REVISION_A) {
+		if (control_status & WD_WDRST)
+			*status |= WDIOF_CARDRESET;
+
+		if (control_status & WD_T110) {
+			*status |= WDIOF_OVERHEAT;
+			if (temp_panic) {
+				pr_info("Temperature overheat trip!\n");
+				kernel_power_off();
+			}
+		}
+	} else {
+		if (control_status & WD_REVC_WTRP)
+			*status |= WDIOF_CARDRESET;
+
+		if (control_status & WD_REVC_TTRP) {
+			*status |= WDIOF_OVERHEAT;
+			if (temp_panic) {
+				pr_info("Temperature overheat trip!\n");
+				kernel_power_off();
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int pcwd_clear_status(void)
+{
+	int control_status;
+
+	if (pcwd_private.revision == PCWD_REVISION_C) {
+		spin_lock(&pcwd_private.io_lock);
+
+		if (debug >= VERBOSE)
+			pr_info("clearing watchdog trip status\n");
+
+		control_status = inb_p(pcwd_private.io_addr + 1);
+
+		if (debug >= DEBUG) {
+			pr_debug("status was: 0x%02x\n", control_status);
+			pr_debug("sending: 0x%02x\n",
+				 (control_status & WD_REVC_R2DS));
+		}
+
+		/* clear reset status & Keep Relay 2 disable state as it is */
+		outb_p((control_status & WD_REVC_R2DS),
+						pcwd_private.io_addr + 1);
+
+		spin_unlock(&pcwd_private.io_lock);
+	}
+	return 0;
+}
+
+static int pcwd_get_temperature(int *temperature)
+{
+	/* check that port 0 gives temperature info and no command results */
+	if (pcwd_private.command_mode)
+		return -1;
+
+	*temperature = 0;
+	if (!pcwd_private.supports_temp)
+		return -ENODEV;
+
+	/*
+	 * Convert celsius to fahrenheit, since this was
+	 * the decided 'standard' for this return value.
+	 */
+	spin_lock(&pcwd_private.io_lock);
+	*temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
+	spin_unlock(&pcwd_private.io_lock);
+
+	if (debug >= DEBUG) {
+		pr_debug("temperature is: %d F\n", *temperature);
+	}
+
+	return 0;
+}
+
+/*
+ *	/dev/watchdog handling
+ */
+
+static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int rv;
+	int status;
+	int temperature;
+	int new_heartbeat;
+	int __user *argp = (int __user *)arg;
+	static const struct watchdog_info ident = {
+		.options =		WDIOF_OVERHEAT |
+					WDIOF_CARDRESET |
+					WDIOF_KEEPALIVEPING |
+					WDIOF_SETTIMEOUT |
+					WDIOF_MAGICCLOSE,
+		.firmware_version =	1,
+		.identity =		"PCWD",
+	};
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		if (copy_to_user(argp, &ident, sizeof(ident)))
+			return -EFAULT;
+		return 0;
+
+	case WDIOC_GETSTATUS:
+		pcwd_get_status(&status);
+		return put_user(status, argp);
+
+	case WDIOC_GETBOOTSTATUS:
+		return put_user(pcwd_private.boot_status, argp);
+
+	case WDIOC_GETTEMP:
+		if (pcwd_get_temperature(&temperature))
+			return -EFAULT;
+
+		return put_user(temperature, argp);
+
+	case WDIOC_SETOPTIONS:
+		if (pcwd_private.revision == PCWD_REVISION_C) {
+			if (get_user(rv, argp))
+				return -EFAULT;
+
+			if (rv & WDIOS_DISABLECARD) {
+				status = pcwd_stop();
+				if (status < 0)
+					return status;
+			}
+			if (rv & WDIOS_ENABLECARD) {
+				status = pcwd_start();
+				if (status < 0)
+					return status;
+			}
+			if (rv & WDIOS_TEMPPANIC)
+				temp_panic = 1;
+		}
+		return -EINVAL;
+
+	case WDIOC_KEEPALIVE:
+		pcwd_keepalive();
+		return 0;
+
+	case WDIOC_SETTIMEOUT:
+		if (get_user(new_heartbeat, argp))
+			return -EFAULT;
+
+		if (pcwd_set_heartbeat(new_heartbeat))
+			return -EINVAL;
+
+		pcwd_keepalive();
+		fallthrough;
+
+	case WDIOC_GETTIMEOUT:
+		return put_user(heartbeat, argp);
+
+	default:
+		return -ENOTTY;
+	}
+
+	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 (test_and_set_bit(0, &open_allowed))
+		return -EBUSY;
+	if (nowayout)
+		__module_get(THIS_MODULE);
+	/* Activate */
+	pcwd_start();
+	pcwd_keepalive();
+	return stream_open(inode, file);
+}
+
+static int pcwd_close(struct inode *inode, struct file *file)
+{
+	if (expect_close == 42)
+		pcwd_stop();
+	else {
+		pr_crit("Unexpected close, not stopping watchdog!\n");
+		pcwd_keepalive();
+	}
+	expect_close = 0;
+	clear_bit(0, &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 (!pcwd_private.supports_temp)
+		return -ENODEV;
+
+	return stream_open(inode, file);
+}
+
+static int pcwd_temp_close(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+/*
+ *	Kernel Interfaces
+ */
+
+static const struct file_operations pcwd_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= pcwd_write,
+	.unlocked_ioctl	= pcwd_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+	.open		= pcwd_open,
+	.release	= pcwd_close,
+};
+
+static struct miscdevice pcwd_miscdev = {
+	.minor =	WATCHDOG_MINOR,
+	.name =		"watchdog",
+	.fops =		&pcwd_fops,
+};
+
+static const 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,
+};
+
+/*
+ *	Init & exit routines
+ */
+
+static inline int get_revision(void)
+{
+	int r = PCWD_REVISION_C;
+
+	spin_lock(&pcwd_private.io_lock);
+	/* REV A cards use only 2 io ports; test
+	 * presumes a floating bus reads as 0xff. */
+	if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
+	    (inb(pcwd_private.io_addr + 3) == 0xFF))
+		r = PCWD_REVISION_A;
+	spin_unlock(&pcwd_private.io_lock);
+
+	return r;
+}
+
+/*
+ *  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 pcwd_isa_match(struct device *dev, unsigned int id)
+{
+	int base_addr = pcwd_ioports[id];
+	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 (debug >= DEBUG)
+		pr_debug("pcwd_isa_match id=%d\n", id);
+
+	if (!request_region(base_addr, 4, "PCWD")) {
+		pr_info("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;
+}
+
+static int pcwd_isa_probe(struct device *dev, unsigned int id)
+{
+	int ret;
+
+	if (debug >= DEBUG)
+		pr_debug("pcwd_isa_probe id=%d\n", id);
+
+	cards_found++;
+	if (cards_found == 1)
+		pr_info("v%s Ken Hollis (kenji@bitgate.com)\n",
+							WATCHDOG_VERSION);
+
+	if (cards_found > 1) {
+		pr_err("This driver only supports 1 device\n");
+		return -ENODEV;
+	}
+
+	if (pcwd_ioports[id] == 0x0000) {
+		pr_err("No I/O-Address for card detected\n");
+		return -ENODEV;
+	}
+	pcwd_private.io_addr = pcwd_ioports[id];
+
+	spin_lock_init(&pcwd_private.io_lock);
+
+	/* Check card's revision */
+	pcwd_private.revision = get_revision();
+
+	if (!request_region(pcwd_private.io_addr,
+		(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
+		pr_err("I/O address 0x%04x already in use\n",
+		       pcwd_private.io_addr);
+		ret = -EIO;
+		goto error_request_region;
+	}
+
+	/* Initial variables */
+	pcwd_private.supports_temp = 0;
+	temp_panic = 0;
+	pcwd_private.boot_status = 0x0000;
+
+	/* get the boot_status */
+	pcwd_get_status(&pcwd_private.boot_status);
+
+	/* clear the "card caused reboot" flag */
+	pcwd_clear_status();
+
+	timer_setup(&pcwd_private.timer, pcwd_timer_ping, 0);
+
+	/*  Disable the board  */
+	pcwd_stop();
+
+	/*  Check whether or not the card supports the temperature device */
+	pcwd_check_temperature_support();
+
+	/* Show info about the card itself */
+	pcwd_show_card_info();
+
+	/* If heartbeat = 0 then we use the heartbeat from the dip-switches */
+	if (heartbeat == 0)
+		heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
+
+	/* 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);
+		pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
+			WATCHDOG_HEARTBEAT);
+	}
+
+	if (pcwd_private.supports_temp) {
+		ret = misc_register(&temp_miscdev);
+		if (ret) {
+			pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+			       TEMP_MINOR, ret);
+			goto error_misc_register_temp;
+		}
+	}
+
+	ret = misc_register(&pcwd_miscdev);
+	if (ret) {
+		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+		       WATCHDOG_MINOR, ret);
+		goto error_misc_register_watchdog;
+	}
+
+	pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
+		heartbeat, nowayout);
+
+	return 0;
+
+error_misc_register_watchdog:
+	if (pcwd_private.supports_temp)
+		misc_deregister(&temp_miscdev);
+error_misc_register_temp:
+	release_region(pcwd_private.io_addr,
+			(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
+error_request_region:
+	pcwd_private.io_addr = 0x0000;
+	cards_found--;
+	return ret;
+}
+
+static void pcwd_isa_remove(struct device *dev, unsigned int id)
+{
+	if (debug >= DEBUG)
+		pr_debug("pcwd_isa_remove id=%d\n", id);
+
+	/*  Disable the board  */
+	if (!nowayout)
+		pcwd_stop();
+
+	/* Deregister */
+	misc_deregister(&pcwd_miscdev);
+	if (pcwd_private.supports_temp)
+		misc_deregister(&temp_miscdev);
+	release_region(pcwd_private.io_addr,
+			(pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
+	pcwd_private.io_addr = 0x0000;
+	cards_found--;
+}
+
+static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
+{
+	if (debug >= DEBUG)
+		pr_debug("pcwd_isa_shutdown id=%d\n", id);
+
+	pcwd_stop();
+}
+
+static struct isa_driver pcwd_isa_driver = {
+	.match		= pcwd_isa_match,
+	.probe		= pcwd_isa_probe,
+	.remove		= pcwd_isa_remove,
+	.shutdown	= pcwd_isa_shutdown,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= WATCHDOG_NAME,
+	},
+};
+
+module_isa_driver(pcwd_isa_driver, PCWD_ISA_NR_CARDS);
+
+MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
+		"Wim Van Sebroeck <wim@iguana.be>");
+MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
+MODULE_VERSION(WATCHDOG_VERSION);
+MODULE_LICENSE("GPL");