3 * by Ken Hollis (khollis@bitgate.com)
5 * Permission granted from Simon Machell (73244.1270@compuserve.com)
6 * Written for the Linux Kernel, and GPLed by Ken Hollis
8 * 960107 Added request_region routines, modulized the whole thing.
9 * 960108 Fixed end-of-file pointer (Thanks to Dan Hollis), added
11 * 960216 Added eof marker on the file, and changed verbose messages.
12 * 960716 Made functional and cosmetic changes to the source for
13 * inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
14 * 960717 Removed read/seek routines, replaced with ioctl. Also, added
15 * check_region command due to Alan's suggestion.
16 * 960821 Made changes to compile in newer 2.0.x kernels. Added
17 * "cold reboot sense" entry.
18 * 960825 Made a few changes to code, deleted some defines and made
19 * typedefs to replace them. Made heartbeat reset only available
20 * via ioctl, and removed the write routine.
21 * 960828 Added new items for PC Watchdog Rev.C card.
22 * 960829 Changed around all of the IOCTLs, added new features,
23 * added watchdog disable/re-enable routines. Added firmware
24 * version reporting. Added read routine for temperature.
25 * Removed some extra defines, added an autodetect Revision
27 * 961006 Revised some documentation, fixed some cosmetic bugs. Made
28 * drivers to panic the system if it's overheating at bootup.
29 * 961118 Changed some verbiage on some of the output, tidied up
30 * code bits, and added compatibility to 2.1.x.
31 * 970912 Enabled board on open and disable on close.
32 * 971107 Took account of recent VFS changes (broke read).
33 * 971210 Disable board on initialisation in case board already ticking.
34 * 971222 Changed open/close for temperature handling
35 * Michael Meskes <meskes@debian.org>.
36 * 980112 Used minor numbers from include/linux/miscdevice.h
37 * 990403 Clear reset status after reading control status register in
38 * pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
39 * 990605 Made changes to code to support Firmware 1.22a, added
40 * fairly useless proc entry.
41 * 990610 removed said useless proc code for the merge <alan>
42 * 000403 Removed last traces of proc code. <davej>
43 * 011214 Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
44 * Added timeout module option to override default
48 * A bells and whistles driver is available from http://www.pcwd.de/
49 * More info available at http://www.berkprod.com/ or http://www.pcwatchdog.com/
52 #include <linux/config.h> /* For CONFIG_WATCHDOG_NOWAYOUT/... */
53 #include <linux/module.h> /* For module specific items */
54 #include <linux/moduleparam.h> /* For new moduleparam's */
55 #include <linux/types.h> /* For standard types (like size_t) */
56 #include <linux/errno.h> /* For the -ENODEV/... values */
57 #include <linux/kernel.h> /* For printk/panic/... */
58 #include <linux/delay.h> /* For mdelay function */
59 #include <linux/timer.h> /* For timer related operations */
60 #include <linux/jiffies.h> /* For jiffies stuff */
61 #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
62 #include <linux/watchdog.h> /* For the watchdog specific items */
63 #include <linux/notifier.h> /* For notifier support */
64 #include <linux/reboot.h> /* For reboot_notifier stuff */
65 #include <linux/init.h> /* For __init/__exit/... */
66 #include <linux/fs.h> /* For file operations */
67 #include <linux/ioport.h> /* For io-port access */
68 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
69 #include <linux/sched.h> /* TASK_INTERRUPTIBLE, set_current_state() and friends */
70 #include <linux/slab.h> /* For kmalloc */
72 #include <asm/uaccess.h> /* For copy_to_user/put_user/... */
73 #include <asm/io.h> /* For inb/outb/... */
75 /* Module and version information */
76 #define WD_VER "1.16 (03/01/2006)"
80 * It should be noted that PCWD_REVISION_B was removed because A and B
81 * are essentially the same types of card, with the exception that B
82 * has temperature reporting. Since I didn't receive a Rev.B card,
83 * the Rev.B card is not supported. (It's a good thing too, as they
84 * are no longer in production.)
86 #define PCWD_REVISION_A 1
87 #define PCWD_REVISION_C 2
90 * These are the defines that describe the control status bits for the
91 * PCI-PC Watchdog card.
93 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
94 #define WD_WDRST 0x01 /* Previously reset state */
95 #define WD_T110 0x02 /* Temperature overheat sense */
96 #define WD_HRTBT 0x04 /* Heartbeat sense */
97 #define WD_RLY2 0x08 /* External relay triggered */
98 #define WD_SRLY2 0x80 /* Software external relay triggered */
99 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
100 #define WD_REVC_WTRP 0x01 /* Watchdog Trip status */
101 #define WD_REVC_HRBT 0x02 /* Watchdog Heartbeat */
102 #define WD_REVC_TTRP 0x04 /* Temperature Trip status */
103 /* Port 2 : Control Status #2 */
104 #define WD_WDIS 0x10 /* Watchdog Disabled */
105 #define WD_ENTP 0x20 /* Watchdog Enable Temperature Trip */
106 #define WD_SSEL 0x40 /* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
107 #define WD_WCMD 0x80 /* Watchdog Command Mode */
109 /* max. time we give an ISA watchdog card to process a command */
110 /* 500ms for each 4 bit response (according to spec.) */
111 #define ISA_COMMAND_TIMEOUT 1000
113 /* Watchdog's internal commands */
114 #define CMD_ISA_IDLE 0x00
115 #define CMD_ISA_VERSION_INTEGER 0x01
116 #define CMD_ISA_VERSION_TENTH 0x02
117 #define CMD_ISA_VERSION_HUNDRETH 0x03
118 #define CMD_ISA_VERSION_MINOR 0x04
119 #define CMD_ISA_SWITCH_SETTINGS 0x05
120 #define CMD_ISA_DELAY_TIME_2SECS 0x0A
121 #define CMD_ISA_DELAY_TIME_4SECS 0x0B
122 #define CMD_ISA_DELAY_TIME_8SECS 0x0C
125 * We are using an kernel timer to do the pinging of the watchdog
126 * every ~500ms. We try to set the internal heartbeat of the
130 #define WDT_INTERVAL (HZ/2+1)
132 /* We can only use 1 card due to the /dev/watchdog restriction */
133 static int cards_found;
135 /* internal variables */
136 static atomic_t open_allowed = ATOMIC_INIT(1);
137 static char expect_close;
138 static int temp_panic;
139 static struct { /* this is private data for each ISA-PC watchdog card */
140 int revision; /* The card's revision */
141 int supports_temp; /* Wether or not the card has a temperature device */
142 int command_mode; /* Wether or not the card is in command mode */
143 int boot_status; /* The card's boot status */
144 int io_addr; /* The cards I/O address */
145 spinlock_t io_lock; /* the lock for io operations */
146 struct timer_list timer; /* The timer that pings the watchdog */
147 unsigned long next_heartbeat; /* the next_heartbeat for the timer */
150 /* module parameters */
151 #define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat */
152 static int heartbeat = WATCHDOG_HEARTBEAT;
153 module_param(heartbeat, int, 0);
154 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
156 static int nowayout = WATCHDOG_NOWAYOUT;
157 module_param(nowayout, int, 0);
158 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
164 static int send_isa_command(int cmd)
168 int port0, last_port0; /* Double read for stabilising */
170 /* The WCMD bit must be 1 and the command is only 4 bits in size */
171 control_status = (cmd & 0x0F) | WD_WCMD;
172 outb_p(control_status, pcwd_private.io_addr + 2);
173 udelay(ISA_COMMAND_TIMEOUT);
175 port0 = inb_p(pcwd_private.io_addr);
176 for (i = 0; i < 25; ++i) {
178 port0 = inb_p(pcwd_private.io_addr);
180 if (port0 == last_port0)
181 break; /* Data is stable */
189 static int set_command_mode(void)
191 int i, found=0, count=0;
193 /* Set the card into command mode */
194 spin_lock(&pcwd_private.io_lock);
195 while ((!found) && (count < 3)) {
196 i = send_isa_command(CMD_ISA_IDLE);
200 else if (i == 0xF3) {
201 /* Card does not like what we've done to it */
202 outb_p(0x00, pcwd_private.io_addr + 2);
203 udelay(1200); /* Spec says wait 1ms */
204 outb_p(0x00, pcwd_private.io_addr + 2);
205 udelay(ISA_COMMAND_TIMEOUT);
209 spin_unlock(&pcwd_private.io_lock);
210 pcwd_private.command_mode = found;
215 static void unset_command_mode(void)
217 /* Set the card into normal mode */
218 spin_lock(&pcwd_private.io_lock);
219 outb_p(0x00, pcwd_private.io_addr + 2);
220 udelay(ISA_COMMAND_TIMEOUT);
221 spin_unlock(&pcwd_private.io_lock);
223 pcwd_private.command_mode = 0;
226 static inline void pcwd_check_temperature_support(void)
228 if (inb(pcwd_private.io_addr) != 0xF0)
229 pcwd_private.supports_temp = 1;
232 static void pcwd_timer_ping(unsigned long data)
236 /* If we got a heartbeat pulse within the WDT_INTERVAL
237 * we agree to ping the WDT */
238 if(time_before(jiffies, pcwd_private.next_heartbeat)) {
239 /* Ping the watchdog */
240 spin_lock(&pcwd_private.io_lock);
241 if (pcwd_private.revision == PCWD_REVISION_A) {
242 /* Rev A cards are reset by setting the WD_WDRST bit in register 1 */
243 wdrst_stat = inb_p(pcwd_private.io_addr);
245 wdrst_stat |= WD_WDRST;
247 outb_p(wdrst_stat, pcwd_private.io_addr + 1);
249 /* Re-trigger watchdog by writing to port 0 */
250 outb_p(0x00, pcwd_private.io_addr);
253 /* Re-set the timer interval */
254 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
256 spin_unlock(&pcwd_private.io_lock);
258 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
262 static int pcwd_start(void)
266 pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
268 /* Start the timer */
269 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
271 /* Enable the port */
272 if (pcwd_private.revision == PCWD_REVISION_C) {
273 spin_lock(&pcwd_private.io_lock);
274 outb_p(0x00, pcwd_private.io_addr + 3);
275 udelay(ISA_COMMAND_TIMEOUT);
276 stat_reg = inb_p(pcwd_private.io_addr + 2);
277 spin_unlock(&pcwd_private.io_lock);
278 if (stat_reg & WD_WDIS) {
279 printk(KERN_INFO PFX "Could not start watchdog\n");
286 static int pcwd_stop(void)
291 del_timer(&pcwd_private.timer);
293 /* Disable the board */
294 if (pcwd_private.revision == PCWD_REVISION_C) {
295 spin_lock(&pcwd_private.io_lock);
296 outb_p(0xA5, pcwd_private.io_addr + 3);
297 udelay(ISA_COMMAND_TIMEOUT);
298 outb_p(0xA5, pcwd_private.io_addr + 3);
299 udelay(ISA_COMMAND_TIMEOUT);
300 stat_reg = inb_p(pcwd_private.io_addr + 2);
301 spin_unlock(&pcwd_private.io_lock);
302 if ((stat_reg & WD_WDIS) == 0) {
303 printk(KERN_INFO PFX "Could not stop watchdog\n");
310 static int pcwd_keepalive(void)
313 pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
317 static int pcwd_set_heartbeat(int t)
319 if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
326 static int pcwd_get_status(int *status)
331 spin_lock(&pcwd_private.io_lock);
332 if (pcwd_private.revision == PCWD_REVISION_A)
333 /* Rev A cards return status information from
334 * the base register, which is used for the
335 * temperature in other cards. */
336 card_status = inb(pcwd_private.io_addr);
338 /* Rev C cards return card status in the base
339 * address + 1 register. And use different bits
340 * to indicate a card initiated reset, and an
341 * over-temperature condition. And the reboot
342 * status can be reset. */
343 card_status = inb(pcwd_private.io_addr + 1);
345 spin_unlock(&pcwd_private.io_lock);
347 if (pcwd_private.revision == PCWD_REVISION_A) {
348 if (card_status & WD_WDRST)
349 *status |= WDIOF_CARDRESET;
351 if (card_status & WD_T110) {
352 *status |= WDIOF_OVERHEAT;
354 printk (KERN_INFO PFX "Temperature overheat trip!\n");
359 if (card_status & WD_REVC_WTRP)
360 *status |= WDIOF_CARDRESET;
362 if (card_status & WD_REVC_TTRP) {
363 *status |= WDIOF_OVERHEAT;
365 printk (KERN_INFO PFX "Temperature overheat trip!\n");
374 static int pcwd_clear_status(void)
376 if (pcwd_private.revision == PCWD_REVISION_C) {
377 spin_lock(&pcwd_private.io_lock);
378 outb_p(0x00, pcwd_private.io_addr + 1); /* clear reset status */
379 spin_unlock(&pcwd_private.io_lock);
384 static int pcwd_get_temperature(int *temperature)
386 /* check that port 0 gives temperature info and no command results */
387 if (pcwd_private.command_mode)
391 if (!pcwd_private.supports_temp)
395 * Convert celsius to fahrenheit, since this was
396 * the decided 'standard' for this return value.
398 spin_lock(&pcwd_private.io_lock);
399 *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
400 spin_unlock(&pcwd_private.io_lock);
406 * /dev/watchdog handling
409 static int pcwd_ioctl(struct inode *inode, struct file *file,
410 unsigned int cmd, unsigned long arg)
416 int __user *argp = (int __user *)arg;
417 static struct watchdog_info ident = {
418 .options = WDIOF_OVERHEAT |
420 WDIOF_KEEPALIVEPING |
423 .firmware_version = 1,
431 case WDIOC_GETSUPPORT:
432 if(copy_to_user(argp, &ident, sizeof(ident)))
436 case WDIOC_GETSTATUS:
437 pcwd_get_status(&status);
438 return put_user(status, argp);
440 case WDIOC_GETBOOTSTATUS:
441 return put_user(pcwd_private.boot_status, argp);
444 if (pcwd_get_temperature(&temperature))
447 return put_user(temperature, argp);
449 case WDIOC_SETOPTIONS:
450 if (pcwd_private.revision == PCWD_REVISION_C)
452 if(copy_from_user(&rv, argp, sizeof(int)))
455 if (rv & WDIOS_DISABLECARD)
460 if (rv & WDIOS_ENABLECARD)
465 if (rv & WDIOS_TEMPPANIC)
472 case WDIOC_KEEPALIVE:
476 case WDIOC_SETTIMEOUT:
477 if (get_user(new_heartbeat, argp))
480 if (pcwd_set_heartbeat(new_heartbeat))
486 case WDIOC_GETTIMEOUT:
487 return put_user(heartbeat, argp);
493 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
500 /* In case it was set long ago */
503 for (i = 0; i != len; i++) {
506 if (get_user(c, buf + i))
517 static int pcwd_open(struct inode *inode, struct file *file)
519 if (!atomic_dec_and_test(&open_allowed) ) {
520 atomic_inc( &open_allowed );
525 __module_get(THIS_MODULE);
530 return nonseekable_open(inode, file);
533 static int pcwd_close(struct inode *inode, struct file *file)
535 if (expect_close == 42) {
538 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
542 atomic_inc( &open_allowed );
547 * /dev/temperature handling
550 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
555 if (pcwd_get_temperature(&temperature))
558 if (copy_to_user(buf, &temperature, 1))
564 static int pcwd_temp_open(struct inode *inode, struct file *file)
566 if (!pcwd_private.supports_temp)
569 return nonseekable_open(inode, file);
572 static int pcwd_temp_close(struct inode *inode, struct file *file)
581 static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
583 if (code==SYS_DOWN || code==SYS_HALT) {
584 /* Turn the WDT off */
595 static struct file_operations pcwd_fops = {
596 .owner = THIS_MODULE,
601 .release = pcwd_close,
604 static struct miscdevice pcwd_miscdev = {
605 .minor = WATCHDOG_MINOR,
610 static struct file_operations pcwd_temp_fops = {
611 .owner = THIS_MODULE,
613 .read = pcwd_temp_read,
614 .open = pcwd_temp_open,
615 .release = pcwd_temp_close,
618 static struct miscdevice temp_miscdev = {
620 .name = "temperature",
621 .fops = &pcwd_temp_fops,
624 static struct notifier_block pcwd_notifier = {
625 .notifier_call = pcwd_notify_sys,
629 * Init & exit routines
632 static inline int get_revision(void)
634 int r = PCWD_REVISION_C;
636 spin_lock(&pcwd_private.io_lock);
637 /* REV A cards use only 2 io ports; test
638 * presumes a floating bus reads as 0xff. */
639 if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
640 (inb(pcwd_private.io_addr + 3) == 0xFF))
642 spin_unlock(&pcwd_private.io_lock);
647 static inline char *get_firmware(void)
649 int one, ten, hund, minor;
652 ret = kmalloc(6, GFP_KERNEL);
656 if (set_command_mode()) {
657 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
658 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
659 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
660 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
661 sprintf(ret, "%c.%c%c%c", one, ten, hund, minor);
664 sprintf(ret, "ERROR");
666 unset_command_mode();
670 static inline int get_option_switches(void)
674 if (set_command_mode()) {
675 /* Get switch settings */
676 rv = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
679 unset_command_mode();
683 static int __devinit pcwatchdog_init(int base_addr)
690 if (cards_found == 1)
691 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
693 if (cards_found > 1) {
694 printk(KERN_ERR PFX "This driver only supports 1 device\n");
698 if (base_addr == 0x0000) {
699 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
702 pcwd_private.io_addr = base_addr;
704 /* Check card's revision */
705 pcwd_private.revision = get_revision();
707 if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
708 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
709 pcwd_private.io_addr);
710 pcwd_private.io_addr = 0x0000;
714 /* Initial variables */
715 pcwd_private.supports_temp = 0;
717 pcwd_private.boot_status = 0x0000;
719 /* get the boot_status */
720 pcwd_get_status(&pcwd_private.boot_status);
722 /* clear the "card caused reboot" flag */
725 init_timer(&pcwd_private.timer);
726 pcwd_private.timer.function = pcwd_timer_ping;
727 pcwd_private.timer.data = 0;
729 /* Disable the board */
732 /* Check whether or not the card supports the temperature device */
733 pcwd_check_temperature_support();
735 /* Get some extra info from the hardware (in command/debug/diag mode) */
736 if (pcwd_private.revision == PCWD_REVISION_A)
737 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
738 else if (pcwd_private.revision == PCWD_REVISION_C) {
739 firmware = get_firmware();
740 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
741 pcwd_private.io_addr, firmware);
743 option_switches = get_option_switches();
744 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
746 ((option_switches & 0x10) ? "ON" : "OFF"),
747 ((option_switches & 0x08) ? "ON" : "OFF"));
749 /* Reprogram internal heartbeat to 2 seconds */
750 if (set_command_mode()) {
751 send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
752 unset_command_mode();
755 /* Should NEVER happen, unless get_revision() fails. */
756 printk(KERN_INFO PFX "Unable to get revision\n");
757 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
758 pcwd_private.io_addr = 0x0000;
762 if (pcwd_private.supports_temp)
763 printk(KERN_INFO PFX "Temperature Option Detected\n");
765 if (pcwd_private.boot_status & WDIOF_CARDRESET)
766 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
768 if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
769 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
770 printk(KERN_EMERG PFX "CPU Overheat\n");
773 if (pcwd_private.boot_status == 0)
774 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
776 /* Check that the heartbeat value is within it's range ; if not reset to the default */
777 if (pcwd_set_heartbeat(heartbeat)) {
778 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
779 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
783 ret = register_reboot_notifier(&pcwd_notifier);
785 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
787 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
788 pcwd_private.io_addr = 0x0000;
792 if (pcwd_private.supports_temp) {
793 ret = misc_register(&temp_miscdev);
795 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
797 unregister_reboot_notifier(&pcwd_notifier);
798 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
799 pcwd_private.io_addr = 0x0000;
804 ret = misc_register(&pcwd_miscdev);
806 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
807 WATCHDOG_MINOR, ret);
808 if (pcwd_private.supports_temp)
809 misc_deregister(&temp_miscdev);
810 unregister_reboot_notifier(&pcwd_notifier);
811 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
812 pcwd_private.io_addr = 0x0000;
816 printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
817 heartbeat, nowayout);
822 static void __devexit pcwatchdog_exit(void)
824 /* Disable the board */
829 misc_deregister(&pcwd_miscdev);
830 if (pcwd_private.supports_temp)
831 misc_deregister(&temp_miscdev);
832 unregister_reboot_notifier(&pcwd_notifier);
833 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
834 pcwd_private.io_addr = 0x0000;
839 * The ISA cards have a heartbeat bit in one of the registers, which
840 * register is card dependent. The heartbeat bit is monitored, and if
841 * found, is considered proof that a Berkshire card has been found.
842 * The initial rate is once per second at board start up, then twice
843 * per second for normal operation.
845 static int __init pcwd_checkcard(int base_addr)
847 int port0, last_port0; /* Reg 0, in case it's REV A */
848 int port1, last_port1; /* Register 1 for REV C cards */
852 if (!request_region (base_addr, 4, "PCWD")) {
853 printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
859 port0 = inb_p(base_addr); /* For REV A boards */
860 port1 = inb_p(base_addr + 1); /* For REV C boards */
861 if (port0 != 0xff || port1 != 0xff) {
862 /* Not an 'ff' from a floating bus, so must be a card! */
863 for (i = 0; i < 4; ++i) {
870 port0 = inb_p(base_addr);
871 port1 = inb_p(base_addr + 1);
873 /* Has either hearbeat bit changed? */
874 if ((port0 ^ last_port0) & WD_HRTBT ||
875 (port1 ^ last_port1) & WD_REVC_HRBT) {
881 release_region (base_addr, 4);
887 * These are the auto-probe addresses available.
889 * Revision A only uses ports 0x270 and 0x370. Revision C introduced 0x350.
890 * Revision A has an address range of 2 addresses, while Revision C has 4.
892 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
894 static int __init pcwd_init_module(void)
898 spin_lock_init(&pcwd_private.io_lock);
900 for (i = 0; pcwd_ioports[i] != 0; i++) {
901 if (pcwd_checkcard(pcwd_ioports[i])) {
902 if (!(pcwatchdog_init(pcwd_ioports[i])))
908 printk (KERN_INFO PFX "No card detected, or port not available\n");
915 static void __exit pcwd_cleanup_module(void)
917 if (pcwd_private.io_addr)
922 module_init(pcwd_init_module);
923 module_exit(pcwd_cleanup_module);
925 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>");
926 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
927 MODULE_LICENSE("GPL");
928 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
929 MODULE_ALIAS_MISCDEV(TEMP_MINOR);