watchdog: nowayout is bool
[linux-2.6.git] / drivers / watchdog / pcwd_usb.c
1 /*
2  *      Berkshire USB-PC Watchdog Card Driver
3  *
4  *      (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>.
5  *
6  *      Based on source code of the following authors:
7  *        Ken Hollis <kenji@bitgate.com>,
8  *        Alan Cox <alan@lxorguk.ukuu.org.uk>,
9  *        Matt Domsch <Matt_Domsch@dell.com>,
10  *        Rob Radez <rob@osinvestor.com>,
11  *        Greg Kroah-Hartman <greg@kroah.com>
12  *
13  *      This program is free software; you can redistribute it and/or
14  *      modify it under the terms of the GNU General Public License
15  *      as published by the Free Software Foundation; either version
16  *      2 of the License, or (at your option) any later version.
17  *
18  *      Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
19  *      provide warranty for any of this software. This material is
20  *      provided "AS-IS" and at no charge.
21  *
22  *      Thanks also to Simon Machell at Berkshire Products Inc. for
23  *      providing the test hardware. More info is available at
24  *      http://www.berkprod.com/ or http://www.pcwatchdog.com/
25  */
26
27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28
29 #include <linux/module.h>       /* For module specific items */
30 #include <linux/moduleparam.h>  /* For new moduleparam's */
31 #include <linux/types.h>        /* For standard types (like size_t) */
32 #include <linux/errno.h>        /* For the -ENODEV/... values */
33 #include <linux/kernel.h>       /* For printk/panic/... */
34 #include <linux/delay.h>        /* For mdelay function */
35 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
36 #include <linux/watchdog.h>     /* For the watchdog specific items */
37 #include <linux/notifier.h>     /* For notifier support */
38 #include <linux/reboot.h>       /* For reboot_notifier stuff */
39 #include <linux/init.h>         /* For __init/__exit/... */
40 #include <linux/fs.h>           /* For file operations */
41 #include <linux/usb.h>          /* For USB functions */
42 #include <linux/slab.h>         /* For kmalloc, ... */
43 #include <linux/mutex.h>        /* For mutex locking */
44 #include <linux/hid.h>          /* For HID_REQ_SET_REPORT & HID_DT_REPORT */
45 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
46
47 #ifdef CONFIG_USB_DEBUG
48 static int debug = 1;
49 #else
50 static int debug;
51 #endif
52
53 /* Use our own dbg macro */
54
55 #undef dbg
56 #ifndef DEBUG
57 #define DEBUG
58 #endif
59 #define dbg(format, ...)                                \
60 do {                                                    \
61         if (debug)                                      \
62                 pr_debug(format "\n", ##__VA_ARGS__);   \
63 } while (0)
64
65 /* Module and Version Information */
66 #define DRIVER_VERSION "1.02"
67 #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>"
68 #define DRIVER_DESC "Berkshire USB-PC Watchdog driver"
69 #define DRIVER_LICENSE "GPL"
70 #define DRIVER_NAME "pcwd_usb"
71
72 MODULE_AUTHOR(DRIVER_AUTHOR);
73 MODULE_DESCRIPTION(DRIVER_DESC);
74 MODULE_LICENSE(DRIVER_LICENSE);
75 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
76 MODULE_ALIAS_MISCDEV(TEMP_MINOR);
77
78 /* Module Parameters */
79 module_param(debug, int, 0);
80 MODULE_PARM_DESC(debug, "Debug enabled or not");
81
82 #define WATCHDOG_HEARTBEAT 0    /* default heartbeat =
83                                                 delay-time from dip-switches */
84 static int heartbeat = WATCHDOG_HEARTBEAT;
85 module_param(heartbeat, int, 0);
86 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
87         "(0<heartbeat<65536 or 0=delay-time from dip-switches, default="
88                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
89
90 static bool nowayout = WATCHDOG_NOWAYOUT;
91 module_param(nowayout, bool, 0);
92 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
93                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
94
95 /* The vendor and product id's for the USB-PC Watchdog card */
96 #define USB_PCWD_VENDOR_ID      0x0c98
97 #define USB_PCWD_PRODUCT_ID     0x1140
98
99 /* table of devices that work with this driver */
100 static struct usb_device_id usb_pcwd_table[] = {
101         { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) },
102         { }                                     /* Terminating entry */
103 };
104 MODULE_DEVICE_TABLE(usb, usb_pcwd_table);
105
106 /* according to documentation max. time to process a command for the USB
107  * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */
108 #define USB_COMMAND_TIMEOUT     250
109
110 /* Watchdog's internal commands */
111 #define CMD_READ_TEMP                   0x02    /* Read Temperature;
112                                                         Re-trigger Watchdog */
113 #define CMD_TRIGGER                     CMD_READ_TEMP
114 #define CMD_GET_STATUS                  0x04    /* Get Status Information */
115 #define CMD_GET_FIRMWARE_VERSION        0x08    /* Get Firmware Version */
116 #define CMD_GET_DIP_SWITCH_SETTINGS     0x0c    /* Get Dip Switch Settings */
117 #define CMD_READ_WATCHDOG_TIMEOUT       0x18    /* Read Current Watchdog Time */
118 #define CMD_WRITE_WATCHDOG_TIMEOUT      0x19    /* Write Current WatchdogTime */
119 #define CMD_ENABLE_WATCHDOG             0x30    /* Enable / Disable Watchdog */
120 #define CMD_DISABLE_WATCHDOG            CMD_ENABLE_WATCHDOG
121
122 /* Watchdog's Dip Switch heartbeat values */
123 static const int heartbeat_tbl[] = {
124         5,      /* OFF-OFF-OFF  =  5 Sec  */
125         10,     /* OFF-OFF-ON   = 10 Sec  */
126         30,     /* OFF-ON-OFF   = 30 Sec  */
127         60,     /* OFF-ON-ON    =  1 Min  */
128         300,    /* ON-OFF-OFF   =  5 Min  */
129         600,    /* ON-OFF-ON    = 10 Min  */
130         1800,   /* ON-ON-OFF    = 30 Min  */
131         3600,   /* ON-ON-ON     =  1 hour */
132 };
133
134 /* We can only use 1 card due to the /dev/watchdog restriction */
135 static int cards_found;
136
137 /* some internal variables */
138 static unsigned long is_active;
139 static char expect_release;
140
141 /* Structure to hold all of our device specific stuff */
142 struct usb_pcwd_private {
143         /* save off the usb device pointer */
144         struct usb_device       *udev;
145         /* the interface for this device */
146         struct usb_interface    *interface;
147
148         /* the interface number used for cmd's */
149         unsigned int            interface_number;
150
151         /* the buffer to intr data */
152         unsigned char           *intr_buffer;
153         /* the dma address for the intr buffer */
154         dma_addr_t              intr_dma;
155         /* the size of the intr buffer */
156         size_t                  intr_size;
157         /* the urb used for the intr pipe */
158         struct urb              *intr_urb;
159
160         /* The command that is reported back */
161         unsigned char           cmd_command;
162         /* The data MSB that is reported back */
163         unsigned char           cmd_data_msb;
164         /* The data LSB that is reported back */
165         unsigned char           cmd_data_lsb;
166         /* true if we received a report after a command */
167         atomic_t                cmd_received;
168
169         /* Wether or not the device exists */
170         int                     exists;
171         /* locks this structure */
172         struct mutex            mtx;
173 };
174 static struct usb_pcwd_private *usb_pcwd_device;
175
176 /* prevent races between open() and disconnect() */
177 static DEFINE_MUTEX(disconnect_mutex);
178
179 /* local function prototypes */
180 static int usb_pcwd_probe(struct usb_interface *interface,
181                                                 const struct usb_device_id *id);
182 static void usb_pcwd_disconnect(struct usb_interface *interface);
183
184 /* usb specific object needed to register this driver with the usb subsystem */
185 static struct usb_driver usb_pcwd_driver = {
186         .name =         DRIVER_NAME,
187         .probe =        usb_pcwd_probe,
188         .disconnect =   usb_pcwd_disconnect,
189         .id_table =     usb_pcwd_table,
190 };
191
192
193 static void usb_pcwd_intr_done(struct urb *urb)
194 {
195         struct usb_pcwd_private *usb_pcwd =
196                                 (struct usb_pcwd_private *)urb->context;
197         unsigned char *data = usb_pcwd->intr_buffer;
198         int retval;
199
200         switch (urb->status) {
201         case 0:                 /* success */
202                 break;
203         case -ECONNRESET:       /* unlink */
204         case -ENOENT:
205         case -ESHUTDOWN:
206                 /* this urb is terminated, clean up */
207                 dbg("%s - urb shutting down with status: %d", __func__,
208                                                                 urb->status);
209                 return;
210         /* -EPIPE:  should clear the halt */
211         default:                /* error */
212                 dbg("%s - nonzero urb status received: %d", __func__,
213                                                                 urb->status);
214                 goto resubmit;
215         }
216
217         dbg("received following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
218                 data[0], data[1], data[2]);
219
220         usb_pcwd->cmd_command  = data[0];
221         usb_pcwd->cmd_data_msb = data[1];
222         usb_pcwd->cmd_data_lsb = data[2];
223
224         /* notify anyone waiting that the cmd has finished */
225         atomic_set(&usb_pcwd->cmd_received, 1);
226
227 resubmit:
228         retval = usb_submit_urb(urb, GFP_ATOMIC);
229         if (retval)
230                 pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n",
231                        retval);
232 }
233
234 static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd,
235                 unsigned char cmd, unsigned char *msb, unsigned char *lsb)
236 {
237         int got_response, count;
238         unsigned char buf[6];
239
240         /* We will not send any commands if the USB PCWD device does
241          * not exist */
242         if ((!usb_pcwd) || (!usb_pcwd->exists))
243                 return -1;
244
245         /* The USB PC Watchdog uses a 6 byte report format.
246          * The board currently uses only 3 of the six bytes of the report. */
247         buf[0] = cmd;                   /* Byte 0 = CMD */
248         buf[1] = *msb;                  /* Byte 1 = Data MSB */
249         buf[2] = *lsb;                  /* Byte 2 = Data LSB */
250         buf[3] = buf[4] = buf[5] = 0;   /* All other bytes not used */
251
252         dbg("sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x",
253                 buf[0], buf[1], buf[2]);
254
255         atomic_set(&usb_pcwd->cmd_received, 0);
256
257         if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0),
258                         HID_REQ_SET_REPORT, HID_DT_REPORT,
259                         0x0200, usb_pcwd->interface_number, buf, sizeof(buf),
260                         USB_COMMAND_TIMEOUT) != sizeof(buf)) {
261                 dbg("usb_pcwd_send_command: error in usb_control_msg for "
262                                 "cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb);
263         }
264         /* wait till the usb card processed the command,
265          * with a max. timeout of USB_COMMAND_TIMEOUT */
266         got_response = 0;
267         for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response);
268                                                                 count++) {
269                 mdelay(1);
270                 if (atomic_read(&usb_pcwd->cmd_received))
271                         got_response = 1;
272         }
273
274         if ((got_response) && (cmd == usb_pcwd->cmd_command)) {
275                 /* read back response */
276                 *msb = usb_pcwd->cmd_data_msb;
277                 *lsb = usb_pcwd->cmd_data_lsb;
278         }
279
280         return got_response;
281 }
282
283 static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd)
284 {
285         unsigned char msb = 0x00;
286         unsigned char lsb = 0x00;
287         int retval;
288
289         /* Enable Watchdog */
290         retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG,
291                                                                 &msb, &lsb);
292
293         if ((retval == 0) || (lsb == 0)) {
294                 pr_err("Card did not acknowledge enable attempt\n");
295                 return -1;
296         }
297
298         return 0;
299 }
300
301 static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd)
302 {
303         unsigned char msb = 0xA5;
304         unsigned char lsb = 0xC3;
305         int retval;
306
307         /* Disable Watchdog */
308         retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG,
309                                                                 &msb, &lsb);
310
311         if ((retval == 0) || (lsb != 0)) {
312                 pr_err("Card did not acknowledge disable attempt\n");
313                 return -1;
314         }
315
316         return 0;
317 }
318
319 static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd)
320 {
321         unsigned char dummy;
322
323         /* Re-trigger Watchdog */
324         usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy);
325
326         return 0;
327 }
328
329 static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t)
330 {
331         unsigned char msb = t / 256;
332         unsigned char lsb = t % 256;
333
334         if ((t < 0x0001) || (t > 0xFFFF))
335                 return -EINVAL;
336
337         /* Write new heartbeat to watchdog */
338         usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb);
339
340         heartbeat = t;
341         return 0;
342 }
343
344 static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd,
345                                                         int *temperature)
346 {
347         unsigned char msb, lsb;
348
349         usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb);
350
351         /*
352          * Convert celsius to fahrenheit, since this was
353          * the decided 'standard' for this return value.
354          */
355         *temperature = (lsb * 9 / 5) + 32;
356
357         return 0;
358 }
359
360 static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd,
361                                                                 int *time_left)
362 {
363         unsigned char msb, lsb;
364
365         /* Read the time that's left before rebooting */
366         /* Note: if the board is not yet armed then we will read 0xFFFF */
367         usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb);
368
369         *time_left = (msb << 8) + lsb;
370
371         return 0;
372 }
373
374 /*
375  *      /dev/watchdog handling
376  */
377
378 static ssize_t usb_pcwd_write(struct file *file, const char __user *data,
379                                                 size_t len, loff_t *ppos)
380 {
381         /* See if we got the magic character 'V' and reload the timer */
382         if (len) {
383                 if (!nowayout) {
384                         size_t i;
385
386                         /* note: just in case someone wrote the magic character
387                          * five months ago... */
388                         expect_release = 0;
389
390                         /* scan to see whether or not we got the
391                          * magic character */
392                         for (i = 0; i != len; i++) {
393                                 char c;
394                                 if (get_user(c, data + i))
395                                         return -EFAULT;
396                                 if (c == 'V')
397                                         expect_release = 42;
398                         }
399                 }
400
401                 /* someone wrote to us, we should reload the timer */
402                 usb_pcwd_keepalive(usb_pcwd_device);
403         }
404         return len;
405 }
406
407 static long usb_pcwd_ioctl(struct file *file, unsigned int cmd,
408                                                 unsigned long arg)
409 {
410         void __user *argp = (void __user *)arg;
411         int __user *p = argp;
412         static const struct watchdog_info ident = {
413                 .options =              WDIOF_KEEPALIVEPING |
414                                         WDIOF_SETTIMEOUT |
415                                         WDIOF_MAGICCLOSE,
416                 .firmware_version =     1,
417                 .identity =             DRIVER_NAME,
418         };
419
420         switch (cmd) {
421         case WDIOC_GETSUPPORT:
422                 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
423
424         case WDIOC_GETSTATUS:
425         case WDIOC_GETBOOTSTATUS:
426                 return put_user(0, p);
427
428         case WDIOC_GETTEMP:
429         {
430                 int temperature;
431
432                 if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
433                         return -EFAULT;
434
435                 return put_user(temperature, p);
436         }
437
438         case WDIOC_SETOPTIONS:
439         {
440                 int new_options, retval = -EINVAL;
441
442                 if (get_user(new_options, p))
443                         return -EFAULT;
444
445                 if (new_options & WDIOS_DISABLECARD) {
446                         usb_pcwd_stop(usb_pcwd_device);
447                         retval = 0;
448                 }
449
450                 if (new_options & WDIOS_ENABLECARD) {
451                         usb_pcwd_start(usb_pcwd_device);
452                         retval = 0;
453                 }
454
455                 return retval;
456         }
457
458         case WDIOC_KEEPALIVE:
459                 usb_pcwd_keepalive(usb_pcwd_device);
460                 return 0;
461
462         case WDIOC_SETTIMEOUT:
463         {
464                 int new_heartbeat;
465
466                 if (get_user(new_heartbeat, p))
467                         return -EFAULT;
468
469                 if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat))
470                         return -EINVAL;
471
472                 usb_pcwd_keepalive(usb_pcwd_device);
473                 /* Fall */
474         }
475
476         case WDIOC_GETTIMEOUT:
477                 return put_user(heartbeat, p);
478
479         case WDIOC_GETTIMELEFT:
480         {
481                 int time_left;
482
483                 if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left))
484                         return -EFAULT;
485
486                 return put_user(time_left, p);
487         }
488
489         default:
490                 return -ENOTTY;
491         }
492 }
493
494 static int usb_pcwd_open(struct inode *inode, struct file *file)
495 {
496         /* /dev/watchdog can only be opened once */
497         if (test_and_set_bit(0, &is_active))
498                 return -EBUSY;
499
500         /* Activate */
501         usb_pcwd_start(usb_pcwd_device);
502         usb_pcwd_keepalive(usb_pcwd_device);
503         return nonseekable_open(inode, file);
504 }
505
506 static int usb_pcwd_release(struct inode *inode, struct file *file)
507 {
508         /*
509          *      Shut off the timer.
510          */
511         if (expect_release == 42) {
512                 usb_pcwd_stop(usb_pcwd_device);
513         } else {
514                 pr_crit("Unexpected close, not stopping watchdog!\n");
515                 usb_pcwd_keepalive(usb_pcwd_device);
516         }
517         expect_release = 0;
518         clear_bit(0, &is_active);
519         return 0;
520 }
521
522 /*
523  *      /dev/temperature handling
524  */
525
526 static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data,
527                                 size_t len, loff_t *ppos)
528 {
529         int temperature;
530
531         if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature))
532                 return -EFAULT;
533
534         if (copy_to_user(data, &temperature, 1))
535                 return -EFAULT;
536
537         return 1;
538 }
539
540 static int usb_pcwd_temperature_open(struct inode *inode, struct file *file)
541 {
542         return nonseekable_open(inode, file);
543 }
544
545 static int usb_pcwd_temperature_release(struct inode *inode, struct file *file)
546 {
547         return 0;
548 }
549
550 /*
551  *      Notify system
552  */
553
554 static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code,
555                                                                 void *unused)
556 {
557         if (code == SYS_DOWN || code == SYS_HALT)
558                 usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */
559
560         return NOTIFY_DONE;
561 }
562
563 /*
564  *      Kernel Interfaces
565  */
566
567 static const struct file_operations usb_pcwd_fops = {
568         .owner =        THIS_MODULE,
569         .llseek =       no_llseek,
570         .write =        usb_pcwd_write,
571         .unlocked_ioctl = usb_pcwd_ioctl,
572         .open =         usb_pcwd_open,
573         .release =      usb_pcwd_release,
574 };
575
576 static struct miscdevice usb_pcwd_miscdev = {
577         .minor =        WATCHDOG_MINOR,
578         .name =         "watchdog",
579         .fops =         &usb_pcwd_fops,
580 };
581
582 static const struct file_operations usb_pcwd_temperature_fops = {
583         .owner =        THIS_MODULE,
584         .llseek =       no_llseek,
585         .read =         usb_pcwd_temperature_read,
586         .open =         usb_pcwd_temperature_open,
587         .release =      usb_pcwd_temperature_release,
588 };
589
590 static struct miscdevice usb_pcwd_temperature_miscdev = {
591         .minor =        TEMP_MINOR,
592         .name =         "temperature",
593         .fops =         &usb_pcwd_temperature_fops,
594 };
595
596 static struct notifier_block usb_pcwd_notifier = {
597         .notifier_call =        usb_pcwd_notify_sys,
598 };
599
600 /**
601  *      usb_pcwd_delete
602  */
603 static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd)
604 {
605         usb_free_urb(usb_pcwd->intr_urb);
606         if (usb_pcwd->intr_buffer != NULL)
607                 usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size,
608                                   usb_pcwd->intr_buffer, usb_pcwd->intr_dma);
609         kfree(usb_pcwd);
610 }
611
612 /**
613  *      usb_pcwd_probe
614  *
615  *      Called by the usb core when a new device is connected that it thinks
616  *      this driver might be interested in.
617  */
618 static int usb_pcwd_probe(struct usb_interface *interface,
619                                                 const struct usb_device_id *id)
620 {
621         struct usb_device *udev = interface_to_usbdev(interface);
622         struct usb_host_interface *iface_desc;
623         struct usb_endpoint_descriptor *endpoint;
624         struct usb_pcwd_private *usb_pcwd = NULL;
625         int pipe, maxp;
626         int retval = -ENOMEM;
627         int got_fw_rev;
628         unsigned char fw_rev_major, fw_rev_minor;
629         char fw_ver_str[20];
630         unsigned char option_switches, dummy;
631
632         cards_found++;
633         if (cards_found > 1) {
634                 pr_err("This driver only supports 1 device\n");
635                 return -ENODEV;
636         }
637
638         /* get the active interface descriptor */
639         iface_desc = interface->cur_altsetting;
640
641         /* check out that we have a HID device */
642         if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) {
643                 pr_err("The device isn't a Human Interface Device\n");
644                 return -ENODEV;
645         }
646
647         /* check out the endpoint: it has to be Interrupt & IN */
648         endpoint = &iface_desc->endpoint[0].desc;
649
650         if (!usb_endpoint_is_int_in(endpoint)) {
651                 /* we didn't find a Interrupt endpoint with direction IN */
652                 pr_err("Couldn't find an INTR & IN endpoint\n");
653                 return -ENODEV;
654         }
655
656         /* get a handle to the interrupt data pipe */
657         pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
658         maxp = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
659
660         /* allocate memory for our device and initialize it */
661         usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL);
662         if (usb_pcwd == NULL) {
663                 pr_err("Out of memory\n");
664                 goto error;
665         }
666
667         usb_pcwd_device = usb_pcwd;
668
669         mutex_init(&usb_pcwd->mtx);
670         usb_pcwd->udev = udev;
671         usb_pcwd->interface = interface;
672         usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber;
673         usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ?
674                                 le16_to_cpu(endpoint->wMaxPacketSize) : 8);
675
676         /* set up the memory buffer's */
677         usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size,
678                                         GFP_ATOMIC, &usb_pcwd->intr_dma);
679         if (!usb_pcwd->intr_buffer) {
680                 pr_err("Out of memory\n");
681                 goto error;
682         }
683
684         /* allocate the urb's */
685         usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
686         if (!usb_pcwd->intr_urb) {
687                 pr_err("Out of memory\n");
688                 goto error;
689         }
690
691         /* initialise the intr urb's */
692         usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe,
693                         usb_pcwd->intr_buffer, usb_pcwd->intr_size,
694                         usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval);
695         usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma;
696         usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
697
698         /* register our interrupt URB with the USB system */
699         if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) {
700                 pr_err("Problem registering interrupt URB\n");
701                 retval = -EIO; /* failure */
702                 goto error;
703         }
704
705         /* The device exists and can be communicated with */
706         usb_pcwd->exists = 1;
707
708         /* disable card */
709         usb_pcwd_stop(usb_pcwd);
710
711         /* Get the Firmware Version */
712         got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION,
713                                                 &fw_rev_major, &fw_rev_minor);
714         if (got_fw_rev)
715                 sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor);
716         else
717                 sprintf(fw_ver_str, "<card no answer>");
718
719         pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str);
720
721         /* Get switch settings */
722         usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy,
723                                                         &option_switches);
724
725         pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
726                 option_switches,
727                 ((option_switches & 0x10) ? "ON" : "OFF"),
728                 ((option_switches & 0x08) ? "ON" : "OFF"));
729
730         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
731         if (heartbeat == 0)
732                 heartbeat = heartbeat_tbl[(option_switches & 0x07)];
733
734         /* Check that the heartbeat value is within it's range ;
735          * if not reset to the default */
736         if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) {
737                 usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT);
738                 pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n",
739                         WATCHDOG_HEARTBEAT);
740         }
741
742         retval = register_reboot_notifier(&usb_pcwd_notifier);
743         if (retval != 0) {
744                 pr_err("cannot register reboot notifier (err=%d)\n", retval);
745                 goto error;
746         }
747
748         retval = misc_register(&usb_pcwd_temperature_miscdev);
749         if (retval != 0) {
750                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
751                        TEMP_MINOR, retval);
752                 goto err_out_unregister_reboot;
753         }
754
755         retval = misc_register(&usb_pcwd_miscdev);
756         if (retval != 0) {
757                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
758                        WATCHDOG_MINOR, retval);
759                 goto err_out_misc_deregister;
760         }
761
762         /* we can register the device now, as it is ready */
763         usb_set_intfdata(interface, usb_pcwd);
764
765         pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
766                 heartbeat, nowayout);
767
768         return 0;
769
770 err_out_misc_deregister:
771         misc_deregister(&usb_pcwd_temperature_miscdev);
772 err_out_unregister_reboot:
773         unregister_reboot_notifier(&usb_pcwd_notifier);
774 error:
775         if (usb_pcwd)
776                 usb_pcwd_delete(usb_pcwd);
777         usb_pcwd_device = NULL;
778         return retval;
779 }
780
781
782 /**
783  *      usb_pcwd_disconnect
784  *
785  *      Called by the usb core when the device is removed from the system.
786  *
787  *      This routine guarantees that the driver will not submit any more urbs
788  *      by clearing dev->udev.
789  */
790 static void usb_pcwd_disconnect(struct usb_interface *interface)
791 {
792         struct usb_pcwd_private *usb_pcwd;
793
794         /* prevent races with open() */
795         mutex_lock(&disconnect_mutex);
796
797         usb_pcwd = usb_get_intfdata(interface);
798         usb_set_intfdata(interface, NULL);
799
800         mutex_lock(&usb_pcwd->mtx);
801
802         /* Stop the timer before we leave */
803         if (!nowayout)
804                 usb_pcwd_stop(usb_pcwd);
805
806         /* We should now stop communicating with the USB PCWD device */
807         usb_pcwd->exists = 0;
808
809         /* Deregister */
810         misc_deregister(&usb_pcwd_miscdev);
811         misc_deregister(&usb_pcwd_temperature_miscdev);
812         unregister_reboot_notifier(&usb_pcwd_notifier);
813
814         mutex_unlock(&usb_pcwd->mtx);
815
816         /* Delete the USB PCWD device */
817         usb_pcwd_delete(usb_pcwd);
818
819         cards_found--;
820
821         mutex_unlock(&disconnect_mutex);
822
823         pr_info("USB PC Watchdog disconnected\n");
824 }
825
826 module_usb_driver(usb_pcwd_driver);