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22
23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/types.h>
28#include <linux/errno.h>
29#include <linux/kernel.h>
30#include <linux/delay.h>
31#include <linux/miscdevice.h>
32#include <linux/watchdog.h>
33#include <linux/notifier.h>
34#include <linux/reboot.h>
35#include <linux/init.h>
36#include <linux/fs.h>
37#include <linux/usb.h>
38#include <linux/slab.h>
39#include <linux/mutex.h>
40#include <linux/hid.h>
41#include <linux/uaccess.h>
42
43
44
45#define DRIVER_VERSION "1.02"
46#define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
47#define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
48#define DRIVER_NAME "pcwd_usb"
49
50MODULE_AUTHOR(DRIVER_AUTHOR);
51MODULE_DESCRIPTION(DRIVER_DESC);
52MODULE_LICENSE("GPL");
53
54#define WATCHDOG_HEARTBEAT 0
55
56static int heartbeat = WATCHDOG_HEARTBEAT;
57module_param(heartbeat, int, 0);
58MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
59 "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
60 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
61
62static bool nowayout = WATCHDOG_NOWAYOUT;
63module_param(nowayout, bool, 0);
64MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
65 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
66
67
68#define USB_PCWD_VENDOR_ID 0x0c98
69#define USB_PCWD_PRODUCT_ID 0x1140
70
71
72static const struct usb_device_id usb_pcwd_table[] = {
73 { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
74 { }
75};
76MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
77
78
79
80#define USB_COMMAND_TIMEOUT 250
81
82
83#define CMD_READ_TEMP 0x02
84
85#define CMD_TRIGGER CMD_READ_TEMP
86#define CMD_GET_STATUS 0x04
87#define CMD_GET_FIRMWARE_VERSION 0x08
88#define CMD_GET_DIP_SWITCH_SETTINGS 0x0c
89#define CMD_READ_WATCHDOG_TIMEOUT 0x18
90#define CMD_WRITE_WATCHDOG_TIMEOUT 0x19
91#define CMD_ENABLE_WATCHDOG 0x30
92#define CMD_DISABLE_WATCHDOG CMD_ENABLE_WATCHDOG
93
94
95static const int heartbeat_tbl[] = {
96 5,
97 10,
98 30,
99 60,
100 300,
101 600,
102 1800,
103 3600,
104};
105
106
107static int cards_found;
108
109
110static unsigned long is_active;
111static char expect_release;
112
113
114struct usb_pcwd_private {
115
116 struct usb_device *udev;
117
118 struct usb_interface *interface;
119
120
121 unsigned int interface_number;
122
123
124 unsigned char *intr_buffer;
125
126 dma_addr_t intr_dma;
127
128 size_t intr_size;
129
130 struct urb *intr_urb;
131
132
133 unsigned char cmd_command;
134
135 unsigned char cmd_data_msb;
136
137 unsigned char cmd_data_lsb;
138
139 atomic_t cmd_received;
140
141
142 int exists;
143
144 struct mutex mtx;
145};
146static struct usb_pcwd_private *usb_pcwd_device;
147
148
149static DEFINE_MUTEX(disconnect_mutex);
150
151
152static int usb_pcwd_probe(struct usb_interface *interface,
153 const struct usb_device_id *id);
154static void usb_pcwd_disconnect(struct usb_interface *interface);
155
156
157static struct usb_driver usb_pcwd_driver = {
158 .name = DRIVER_NAME,
159 .probe = usb_pcwd_probe,
160 .disconnect = usb_pcwd_disconnect,
161 .id_table = usb_pcwd_table,
162};
163
164
165static void usb_pcwd_intr_done(struct urb *urb)
166{
167 struct usb_pcwd_private *usb_pcwd =
168 (struct usb_pcwd_private *)urb->context;
169 unsigned char *data = usb_pcwd->intr_buffer;
170 struct device *dev = &usb_pcwd->interface->dev;
171 int retval;
172
173 switch (urb->status) {
174 case 0:
175 break;
176 case -ECONNRESET:
177 case -ENOENT:
178 case -ESHUTDOWN:
179
180 dev_dbg(dev, "%s - urb shutting down with status: %d",
181 __func__, urb->status);
182 return;
183
184 default:
185 dev_dbg(dev, "%s - nonzero urb status received: %d",
186 __func__, urb->status);
187 goto resubmit;
188 }
189
190 dev_dbg(dev, "received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
191 data[0], data[1], data[2]);
192
193 usb_pcwd->cmd_command = data[0];
194 usb_pcwd->cmd_data_msb = data[1];
195 usb_pcwd->cmd_data_lsb = data[2];
196
197
198 atomic_set(&usb_pcwd->cmd_received, 1);
199
200resubmit:
201 retval = usb_submit_urb(urb, GFP_ATOMIC);
202 if (retval)
203 pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n",
204 retval);
205}
206
207static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
208 unsigned char cmd, unsigned char *msb, unsigned char *lsb)
209{
210 int got_response, count;
211 unsigned char *buf;
212
213
214
215 if ((!usb_pcwd) || (!usb_pcwd->exists))
216 return -1;
217
218 buf = kmalloc(6, GFP_KERNEL);
219 if (buf == NULL)
220 return 0;
221
222
223
224 buf[0] = cmd;
225 buf[1] = *msb;
226 buf[2] = *lsb;
227 buf[3] = buf[4] = buf[5] = 0;
228
229 dev_dbg(&usb_pcwd->interface->dev,
230 "sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
231 buf[0], buf[1], buf[2]);
232
233 atomic_set(&usb_pcwd->cmd_received, 0);
234
235 if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
236 HID_REQ_SET_REPORT, HID_DT_REPORT,
237 0x0200, usb_pcwd->interface_number, buf, 6,
238 USB_COMMAND_TIMEOUT) != 6) {
239 dev_dbg(&usb_pcwd->interface->dev,
240 "usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n",
241 cmd, *msb, *lsb);
242 }
243
244
245 got_response = 0;
246 for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
247 count++) {
248 mdelay(1);
249 if (atomic_read(&usb_pcwd->cmd_received))
250 got_response = 1;
251 }
252
253 if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
254
255 *msb = usb_pcwd->cmd_data_msb;
256 *lsb = usb_pcwd->cmd_data_lsb;
257 }
258
259 kfree(buf);
260
261 return got_response;
262}
263
264static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
265{
266 unsigned char msb = 0x00;
267 unsigned char lsb = 0x00;
268 int retval;
269
270
271 retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
272 &msb, &lsb);
273
274 if ((retval == 0) || (lsb == 0)) {
275 pr_err("Card did not acknowledge enable attempt\n");
276 return -1;
277 }
278
279 return 0;
280}
281
282static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
283{
284 unsigned char msb = 0xA5;
285 unsigned char lsb = 0xC3;
286 int retval;
287
288
289 retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
290 &msb, &lsb);
291
292 if ((retval == 0) || (lsb != 0)) {
293 pr_err("Card did not acknowledge disable attempt\n");
294 return -1;
295 }
296
297 return 0;
298}
299
300static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
301{
302 unsigned char dummy;
303
304
305 usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
306
307 return 0;
308}
309
310static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
311{
312 unsigned char msb = t / 256;
313 unsigned char lsb = t % 256;
314
315 if ((t < 0x0001) || (t > 0xFFFF))
316 return -EINVAL;
317
318
319 usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
320
321 heartbeat = t;
322 return 0;
323}
324
325static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
326 int *temperature)
327{
328 unsigned char msb, lsb;
329
330 usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
331
332
333
334
335
336 *temperature = (lsb * 9 / 5) + 32;
337
338 return 0;
339}
340
341static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
342 int *time_left)
343{
344 unsigned char msb, lsb;
345
346
347
348 usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
349
350 *time_left = (msb << 8) + lsb;
351
352 return 0;
353}
354
355
356
357
358
359static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
360 size_t len, loff_t *ppos)
361{
362
363 if (len) {
364 if (!nowayout) {
365 size_t i;
366
367
368
369 expect_release = 0;
370
371
372
373 for (i = 0; i != len; i++) {
374 char c;
375 if (get_user(c, data + i))
376 return -EFAULT;
377 if (c == 'V')
378 expect_release = 42;
379 }
380 }
381
382
383 usb_pcwd_keepalive(usb_pcwd_device);
384 }
385 return len;
386}
387
388static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
389 unsigned long arg)
390{
391 void __user *argp = (void __user *)arg;
392 int __user *p = argp;
393 static const struct watchdog_info ident = {
394 .options = WDIOF_KEEPALIVEPING |
395 WDIOF_SETTIMEOUT |
396 WDIOF_MAGICCLOSE,
397 .firmware_version = 1,
398 .identity = DRIVER_NAME,
399 };
400
401 switch (cmd) {
402 case WDIOC_GETSUPPORT:
403 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
404
405 case WDIOC_GETSTATUS:
406 case WDIOC_GETBOOTSTATUS:
407 return put_user(0, p);
408
409 case WDIOC_GETTEMP:
410 {
411 int temperature;
412
413 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
414 return -EFAULT;
415
416 return put_user(temperature, p);
417 }
418
419 case WDIOC_SETOPTIONS:
420 {
421 int new_options, retval = -EINVAL;
422
423 if (get_user(new_options, p))
424 return -EFAULT;
425
426 if (new_options & WDIOS_DISABLECARD) {
427 usb_pcwd_stop(usb_pcwd_device);
428 retval = 0;
429 }
430
431 if (new_options & WDIOS_ENABLECARD) {
432 usb_pcwd_start(usb_pcwd_device);
433 retval = 0;
434 }
435
436 return retval;
437 }
438
439 case WDIOC_KEEPALIVE:
440 usb_pcwd_keepalive(usb_pcwd_device);
441 return 0;
442
443 case WDIOC_SETTIMEOUT:
444 {
445 int new_heartbeat;
446
447 if (get_user(new_heartbeat, p))
448 return -EFAULT;
449
450 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
451 return -EINVAL;
452
453 usb_pcwd_keepalive(usb_pcwd_device);
454 }
455 fallthrough;
456
457 case WDIOC_GETTIMEOUT:
458 return put_user(heartbeat, p);
459
460 case WDIOC_GETTIMELEFT:
461 {
462 int time_left;
463
464 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
465 return -EFAULT;
466
467 return put_user(time_left, p);
468 }
469
470 default:
471 return -ENOTTY;
472 }
473}
474
475static int usb_pcwd_open(struct inode *inode, struct file *file)
476{
477
478 if (test_and_set_bit(0, &is_active))
479 return -EBUSY;
480
481
482 usb_pcwd_start(usb_pcwd_device);
483 usb_pcwd_keepalive(usb_pcwd_device);
484 return stream_open(inode, file);
485}
486
487static int usb_pcwd_release(struct inode *inode, struct file *file)
488{
489
490
491
492 if (expect_release == 42) {
493 usb_pcwd_stop(usb_pcwd_device);
494 } else {
495 pr_crit("Unexpected close, not stopping watchdog!\n");
496 usb_pcwd_keepalive(usb_pcwd_device);
497 }
498 expect_release = 0;
499 clear_bit(0, &is_active);
500 return 0;
501}
502
503
504
505
506
507static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
508 size_t len, loff_t *ppos)
509{
510 int temperature;
511
512 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
513 return -EFAULT;
514
515 if (copy_to_user(data, &temperature, 1))
516 return -EFAULT;
517
518 return 1;
519}
520
521static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
522{
523 return stream_open(inode, file);
524}
525
526static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
527{
528 return 0;
529}
530
531
532
533
534
535static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
536 void *unused)
537{
538 if (code == SYS_DOWN || code == SYS_HALT)
539 usb_pcwd_stop(usb_pcwd_device);
540
541 return NOTIFY_DONE;
542}
543
544
545
546
547
548static const struct file_operations usb_pcwd_fops = {
549 .owner = THIS_MODULE,
550 .llseek = no_llseek,
551 .write = usb_pcwd_write,
552 .unlocked_ioctl = usb_pcwd_ioctl,
553 .compat_ioctl = compat_ptr_ioctl,
554 .open = usb_pcwd_open,
555 .release = usb_pcwd_release,
556};
557
558static struct miscdevice usb_pcwd_miscdev = {
559 .minor = WATCHDOG_MINOR,
560 .name = "watchdog",
561 .fops = &usb_pcwd_fops,
562};
563
564static const struct file_operations usb_pcwd_temperature_fops = {
565 .owner = THIS_MODULE,
566 .llseek = no_llseek,
567 .read = usb_pcwd_temperature_read,
568 .open = usb_pcwd_temperature_open,
569 .release = usb_pcwd_temperature_release,
570};
571
572static struct miscdevice usb_pcwd_temperature_miscdev = {
573 .minor = TEMP_MINOR,
574 .name = "temperature",
575 .fops = &usb_pcwd_temperature_fops,
576};
577
578static struct notifier_block usb_pcwd_notifier = {
579 .notifier_call = usb_pcwd_notify_sys,
580};
581
582
583
584
585static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
586{
587 usb_free_urb(usb_pcwd->intr_urb);
588 usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
589 usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
590 kfree(usb_pcwd);
591}
592
593
594
595
596
597
598
599static int usb_pcwd_probe(struct usb_interface *interface,
600 const struct usb_device_id *id)
601{
602 struct usb_device *udev = interface_to_usbdev(interface);
603 struct usb_host_interface *iface_desc;
604 struct usb_endpoint_descriptor *endpoint;
605 struct usb_pcwd_private *usb_pcwd = NULL;
606 int pipe;
607 int retval = -ENOMEM;
608 int got_fw_rev;
609 unsigned char fw_rev_major, fw_rev_minor;
610 char fw_ver_str[20];
611 unsigned char option_switches, dummy;
612
613 cards_found++;
614 if (cards_found > 1) {
615 pr_err("This driver only supports 1 device\n");
616 return -ENODEV;
617 }
618
619
620 iface_desc = interface->cur_altsetting;
621
622
623 if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
624 pr_err("The device isn't a Human Interface Device\n");
625 return -ENODEV;
626 }
627
628 if (iface_desc->desc.bNumEndpoints < 1)
629 return -ENODEV;
630
631
632 endpoint = &iface_desc->endpoint[0].desc;
633
634 if (!usb_endpoint_is_int_in(endpoint)) {
635
636 pr_err("Couldn't find an INTR & IN endpoint\n");
637 return -ENODEV;
638 }
639
640
641 pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
642
643
644 usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
645 if (usb_pcwd == NULL)
646 goto error;
647
648 usb_pcwd_device = usb_pcwd;
649
650 mutex_init(&usb_pcwd->mtx);
651 usb_pcwd->udev = udev;
652 usb_pcwd->interface = interface;
653 usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
654 usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
655 le16_to_cpu(endpoint->wMaxPacketSize) : 8);
656
657
658 usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
659 GFP_KERNEL, &usb_pcwd->intr_dma);
660 if (!usb_pcwd->intr_buffer) {
661 pr_err("Out of memory\n");
662 goto error;
663 }
664
665
666 usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
667 if (!usb_pcwd->intr_urb)
668 goto error;
669
670
671 usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
672 usb_pcwd->intr_buffer, usb_pcwd->intr_size,
673 usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
674 usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
675 usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
676
677
678 if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
679 pr_err("Problem registering interrupt URB\n");
680 retval = -EIO;
681 goto error;
682 }
683
684
685 usb_pcwd->exists = 1;
686
687
688 usb_pcwd_stop(usb_pcwd);
689
690
691 got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
692 &fw_rev_major, &fw_rev_minor);
693 if (got_fw_rev)
694 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
695 else
696 sprintf(fw_ver_str, "<card no answer>");
697
698 pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str);
699
700
701 usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
702 &option_switches);
703
704 pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
705 option_switches,
706 ((option_switches & 0x10) ? "ON" : "OFF"),
707 ((option_switches & 0x08) ? "ON" : "OFF"));
708
709
710 if (heartbeat == 0)
711 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
712
713
714
715 if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
716 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
717 pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
718 WATCHDOG_HEARTBEAT);
719 }
720
721 retval = register_reboot_notifier(&usb_pcwd_notifier);
722 if (retval != 0) {
723 pr_err("cannot register reboot notifier (err=%d)\n", retval);
724 goto error;
725 }
726
727 retval = misc_register(&usb_pcwd_temperature_miscdev);
728 if (retval != 0) {
729 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
730 TEMP_MINOR, retval);
731 goto err_out_unregister_reboot;
732 }
733
734 retval = misc_register(&usb_pcwd_miscdev);
735 if (retval != 0) {
736 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
737 WATCHDOG_MINOR, retval);
738 goto err_out_misc_deregister;
739 }
740
741
742 usb_set_intfdata(interface, usb_pcwd);
743
744 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
745 heartbeat, nowayout);
746
747 return 0;
748
749err_out_misc_deregister:
750 misc_deregister(&usb_pcwd_temperature_miscdev);
751err_out_unregister_reboot:
752 unregister_reboot_notifier(&usb_pcwd_notifier);
753error:
754 if (usb_pcwd)
755 usb_pcwd_delete(usb_pcwd);
756 usb_pcwd_device = NULL;
757 return retval;
758}
759
760
761
762
763
764
765
766
767
768
769static void usb_pcwd_disconnect(struct usb_interface *interface)
770{
771 struct usb_pcwd_private *usb_pcwd;
772
773
774 mutex_lock(&disconnect_mutex);
775
776 usb_pcwd = usb_get_intfdata(interface);
777 usb_set_intfdata(interface, NULL);
778
779 mutex_lock(&usb_pcwd->mtx);
780
781
782 if (!nowayout)
783 usb_pcwd_stop(usb_pcwd);
784
785
786 usb_pcwd->exists = 0;
787
788
789 misc_deregister(&usb_pcwd_miscdev);
790 misc_deregister(&usb_pcwd_temperature_miscdev);
791 unregister_reboot_notifier(&usb_pcwd_notifier);
792
793 mutex_unlock(&usb_pcwd->mtx);
794
795
796 usb_pcwd_delete(usb_pcwd);
797
798 cards_found--;
799
800 mutex_unlock(&disconnect_mutex);
801
802 pr_info("USB PC Watchdog disconnected\n");
803}
804
805module_usb_driver(usb_pcwd_driver);
806