Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/drivers/usb/misc/adutux.c

  1 /*
  2  * adutux - driver for ADU devices from Ontrak Control Systems
  3  * This is an experimental driver. Use at your own risk.
  4  * This driver is not supported by Ontrak Control Systems.
  5  *
  6  * Copyright (c) 2003 John Homppi (SCO, leave this notice here)
  7  *
  8  * This program is free software; you can redistribute it and/or
  9  * modify it under the terms of the GNU General Public License as
 10  * published by the Free Software Foundation; either version 2 of
 11  * the License, or (at your option) any later version.
 12  *
 13  * derived from the Lego USB Tower driver 0.56:
 14  * Copyright (c) 2003 David Glance <davidgsf@sourceforge.net>
 15  *               2001 Juergen Stuber <stuber@loria.fr>
 16  * that was derived from USB Skeleton driver - 0.5
 17  * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
 18  *
 19  */
 20 
 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 22 
 23 #include <linux/kernel.h>
 24 #include <linux/errno.h>
 25 #include <linux/slab.h>
 26 #include <linux/module.h>
 27 #include <linux/usb.h>
 28 #include <linux/mutex.h>
 29 #include <linux/uaccess.h>
 30 
 31 /* Version Information */
 32 #define DRIVER_VERSION "v0.0.13"
 33 #define DRIVER_AUTHOR "John Homppi"
 34 #define DRIVER_DESC "adutux (see www.ontrak.net)"
 35 
 36 /* Define these values to match your device */
 37 #define ADU_VENDOR_ID 0x0a07
 38 #define ADU_PRODUCT_ID 0x0064
 39 
 40 /* table of devices that work with this driver */
 41 static const struct usb_device_id device_table[] = {
 42         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) },          /* ADU100 */
 43         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) },       /* ADU120 */
 44         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) },       /* ADU130 */
 45         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) },      /* ADU200 */
 46         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) },      /* ADU208 */
 47         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) },      /* ADU218 */
 48         { } /* Terminating entry */
 49 };
 50 
 51 MODULE_DEVICE_TABLE(usb, device_table);
 52 
 53 #ifdef CONFIG_USB_DYNAMIC_MINORS
 54 #define ADU_MINOR_BASE  0
 55 #else
 56 #define ADU_MINOR_BASE  67
 57 #endif
 58 
 59 /* we can have up to this number of device plugged in at once */
 60 #define MAX_DEVICES     16
 61 
 62 #define COMMAND_TIMEOUT (2*HZ)  /* 60 second timeout for a command */
 63 
 64 /*
 65  * The locking scheme is a vanilla 3-lock:
 66  *   adu_device.buflock: A spinlock, covers what IRQs touch.
 67  *   adutux_mutex:       A Static lock to cover open_count. It would also cover
 68  *                       any globals, but we don't have them in 2.6.
 69  *   adu_device.mtx:     A mutex to hold across sleepers like copy_from_user.
 70  *                       It covers all of adu_device, except the open_count
 71  *                       and what .buflock covers.
 72  */
 73 
 74 /* Structure to hold all of our device specific stuff */
 75 struct adu_device {
 76         struct mutex            mtx;
 77         struct usb_device *udev; /* save off the usb device pointer */
 78         struct usb_interface *interface;
 79         unsigned int            minor; /* the starting minor number for this device */
 80         char                    serial_number[8];
 81 
 82         int                     open_count; /* number of times this port has been opened */
 83 
 84         char            *read_buffer_primary;
 85         int                     read_buffer_length;
 86         char            *read_buffer_secondary;
 87         int                     secondary_head;
 88         int                     secondary_tail;
 89         spinlock_t              buflock;
 90 
 91         wait_queue_head_t       read_wait;
 92         wait_queue_head_t       write_wait;
 93 
 94         char            *interrupt_in_buffer;
 95         struct usb_endpoint_descriptor *interrupt_in_endpoint;
 96         struct urb      *interrupt_in_urb;
 97         int                     read_urb_finished;
 98 
 99         char            *interrupt_out_buffer;
100         struct usb_endpoint_descriptor *interrupt_out_endpoint;
101         struct urb      *interrupt_out_urb;
102         int                     out_urb_finished;
103 };
104 
105 static DEFINE_MUTEX(adutux_mutex);
106 
107 static struct usb_driver adu_driver;
108 
109 static inline void adu_debug_data(struct device *dev, const char *function,
110                                   int size, const unsigned char *data)
111 {
112         dev_dbg(dev, "%s - length = %d, data = %*ph\n",
113                 function, size, size, data);
114 }
115 
116 /**
117  * adu_abort_transfers
118  *      aborts transfers and frees associated data structures
119  */
120 static void adu_abort_transfers(struct adu_device *dev)
121 {
122         unsigned long flags;
123 
124         if (dev->udev == NULL)
125                 return;
126 
127         /* shutdown transfer */
128 
129         /* XXX Anchor these instead */
130         spin_lock_irqsave(&dev->buflock, flags);
131         if (!dev->read_urb_finished) {
132                 spin_unlock_irqrestore(&dev->buflock, flags);
133                 usb_kill_urb(dev->interrupt_in_urb);
134         } else
135                 spin_unlock_irqrestore(&dev->buflock, flags);
136 
137         spin_lock_irqsave(&dev->buflock, flags);
138         if (!dev->out_urb_finished) {
139                 spin_unlock_irqrestore(&dev->buflock, flags);
140                 usb_kill_urb(dev->interrupt_out_urb);
141         } else
142                 spin_unlock_irqrestore(&dev->buflock, flags);
143 }
144 
145 static void adu_delete(struct adu_device *dev)
146 {
147         /* free data structures */
148         usb_free_urb(dev->interrupt_in_urb);
149         usb_free_urb(dev->interrupt_out_urb);
150         kfree(dev->read_buffer_primary);
151         kfree(dev->read_buffer_secondary);
152         kfree(dev->interrupt_in_buffer);
153         kfree(dev->interrupt_out_buffer);
154         kfree(dev);
155 }
156 
157 static void adu_interrupt_in_callback(struct urb *urb)
158 {
159         struct adu_device *dev = urb->context;
160         int status = urb->status;
161 
162         adu_debug_data(&dev->udev->dev, __func__,
163                        urb->actual_length, urb->transfer_buffer);
164 
165         spin_lock(&dev->buflock);
166 
167         if (status != 0) {
168                 if ((status != -ENOENT) && (status != -ECONNRESET) &&
169                         (status != -ESHUTDOWN)) {
170                         dev_dbg(&dev->udev->dev,
171                                 "%s : nonzero status received: %d\n",
172                                 __func__, status);
173                 }
174                 goto exit;
175         }
176 
177         if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
178                 if (dev->read_buffer_length <
179                     (4 * usb_endpoint_maxp(dev->interrupt_in_endpoint)) -
180                      (urb->actual_length)) {
181                         memcpy (dev->read_buffer_primary +
182                                 dev->read_buffer_length,
183                                 dev->interrupt_in_buffer, urb->actual_length);
184 
185                         dev->read_buffer_length += urb->actual_length;
186                         dev_dbg(&dev->udev->dev,"%s reading  %d\n", __func__,
187                                 urb->actual_length);
188                 } else {
189                         dev_dbg(&dev->udev->dev,"%s : read_buffer overflow\n",
190                                 __func__);
191                 }
192         }
193 
194 exit:
195         dev->read_urb_finished = 1;
196         spin_unlock(&dev->buflock);
197         /* always wake up so we recover from errors */
198         wake_up_interruptible(&dev->read_wait);
199 }
200 
201 static void adu_interrupt_out_callback(struct urb *urb)
202 {
203         struct adu_device *dev = urb->context;
204         int status = urb->status;
205 
206         adu_debug_data(&dev->udev->dev, __func__,
207                        urb->actual_length, urb->transfer_buffer);
208 
209         if (status != 0) {
210                 if ((status != -ENOENT) &&
211                     (status != -ECONNRESET)) {
212                         dev_dbg(&dev->udev->dev,
213                                 "%s :nonzero status received: %d\n", __func__,
214                                 status);
215                 }
216                 return;
217         }
218 
219         spin_lock(&dev->buflock);
220         dev->out_urb_finished = 1;
221         wake_up(&dev->write_wait);
222         spin_unlock(&dev->buflock);
223 }
224 
225 static int adu_open(struct inode *inode, struct file *file)
226 {
227         struct adu_device *dev = NULL;
228         struct usb_interface *interface;
229         int subminor;
230         int retval;
231 
232         subminor = iminor(inode);
233 
234         retval = mutex_lock_interruptible(&adutux_mutex);
235         if (retval)
236                 goto exit_no_lock;
237 
238         interface = usb_find_interface(&adu_driver, subminor);
239         if (!interface) {
240                 pr_err("%s - error, can't find device for minor %d\n",
241                        __func__, subminor);
242                 retval = -ENODEV;
243                 goto exit_no_device;
244         }
245 
246         dev = usb_get_intfdata(interface);
247         if (!dev || !dev->udev) {
248                 retval = -ENODEV;
249                 goto exit_no_device;
250         }
251 
252         /* check that nobody else is using the device */
253         if (dev->open_count) {
254                 retval = -EBUSY;
255                 goto exit_no_device;
256         }
257 
258         ++dev->open_count;
259         dev_dbg(&dev->udev->dev, "%s: open count %d\n", __func__,
260                 dev->open_count);
261 
262         /* save device in the file's private structure */
263         file->private_data = dev;
264 
265         /* initialize in direction */
266         dev->read_buffer_length = 0;
267 
268         /* fixup first read by having urb waiting for it */
269         usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
270                          usb_rcvintpipe(dev->udev,
271                                         dev->interrupt_in_endpoint->bEndpointAddress),
272                          dev->interrupt_in_buffer,
273                          usb_endpoint_maxp(dev->interrupt_in_endpoint),
274                          adu_interrupt_in_callback, dev,
275                          dev->interrupt_in_endpoint->bInterval);
276         dev->read_urb_finished = 0;
277         if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
278                 dev->read_urb_finished = 1;
279         /* we ignore failure */
280         /* end of fixup for first read */
281 
282         /* initialize out direction */
283         dev->out_urb_finished = 1;
284 
285         retval = 0;
286 
287 exit_no_device:
288         mutex_unlock(&adutux_mutex);
289 exit_no_lock:
290         return retval;
291 }
292 
293 static void adu_release_internal(struct adu_device *dev)
294 {
295         /* decrement our usage count for the device */
296         --dev->open_count;
297         dev_dbg(&dev->udev->dev, "%s : open count %d\n", __func__,
298                 dev->open_count);
299         if (dev->open_count <= 0) {
300                 adu_abort_transfers(dev);
301                 dev->open_count = 0;
302         }
303 }
304 
305 static int adu_release(struct inode *inode, struct file *file)
306 {
307         struct adu_device *dev;
308         int retval = 0;
309 
310         if (file == NULL) {
311                 retval = -ENODEV;
312                 goto exit;
313         }
314 
315         dev = file->private_data;
316         if (dev == NULL) {
317                 retval = -ENODEV;
318                 goto exit;
319         }
320 
321         mutex_lock(&adutux_mutex); /* not interruptible */
322 
323         if (dev->open_count <= 0) {
324                 dev_dbg(&dev->udev->dev, "%s : device not opened\n", __func__);
325                 retval = -ENODEV;
326                 goto unlock;
327         }
328 
329         adu_release_internal(dev);
330         if (dev->udev == NULL) {
331                 /* the device was unplugged before the file was released */
332                 if (!dev->open_count)   /* ... and we're the last user */
333                         adu_delete(dev);
334         }
335 unlock:
336         mutex_unlock(&adutux_mutex);
337 exit:
338         return retval;
339 }
340 
341 static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
342                         loff_t *ppos)
343 {
344         struct adu_device *dev;
345         size_t bytes_read = 0;
346         size_t bytes_to_read = count;
347         int i;
348         int retval = 0;
349         int timeout = 0;
350         int should_submit = 0;
351         unsigned long flags;
352         DECLARE_WAITQUEUE(wait, current);
353 
354         dev = file->private_data;
355         if (mutex_lock_interruptible(&dev->mtx))
356                 return -ERESTARTSYS;
357 
358         /* verify that the device wasn't unplugged */
359         if (dev->udev == NULL) {
360                 retval = -ENODEV;
361                 pr_err("No device or device unplugged %d\n", retval);
362                 goto exit;
363         }
364 
365         /* verify that some data was requested */
366         if (count == 0) {
367                 dev_dbg(&dev->udev->dev, "%s : read request of 0 bytes\n",
368                         __func__);
369                 goto exit;
370         }
371 
372         timeout = COMMAND_TIMEOUT;
373         dev_dbg(&dev->udev->dev, "%s : about to start looping\n", __func__);
374         while (bytes_to_read) {
375                 int data_in_secondary = dev->secondary_tail - dev->secondary_head;
376                 dev_dbg(&dev->udev->dev,
377                         "%s : while, data_in_secondary=%d, status=%d\n",
378                         __func__, data_in_secondary,
379                         dev->interrupt_in_urb->status);
380 
381                 if (data_in_secondary) {
382                         /* drain secondary buffer */
383                         int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
384                         i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
385                         if (i) {
386                                 retval = -EFAULT;
387                                 goto exit;
388                         }
389                         dev->secondary_head += (amount - i);
390                         bytes_read += (amount - i);
391                         bytes_to_read -= (amount - i);
392                         if (i) {
393                                 retval = bytes_read ? bytes_read : -EFAULT;
394                                 goto exit;
395                         }
396                 } else {
397                         /* we check the primary buffer */
398                         spin_lock_irqsave (&dev->buflock, flags);
399                         if (dev->read_buffer_length) {
400                                 /* we secure access to the primary */
401                                 char *tmp;
402                                 dev_dbg(&dev->udev->dev,
403                                         "%s : swap, read_buffer_length = %d\n",
404                                         __func__, dev->read_buffer_length);
405                                 tmp = dev->read_buffer_secondary;
406                                 dev->read_buffer_secondary = dev->read_buffer_primary;
407                                 dev->read_buffer_primary = tmp;
408                                 dev->secondary_head = 0;
409                                 dev->secondary_tail = dev->read_buffer_length;
410                                 dev->read_buffer_length = 0;
411                                 spin_unlock_irqrestore(&dev->buflock, flags);
412                                 /* we have a free buffer so use it */
413                                 should_submit = 1;
414                         } else {
415                                 /* even the primary was empty - we may need to do IO */
416                                 if (!dev->read_urb_finished) {
417                                         /* somebody is doing IO */
418                                         spin_unlock_irqrestore(&dev->buflock, flags);
419                                         dev_dbg(&dev->udev->dev,
420                                                 "%s : submitted already\n",
421                                                 __func__);
422                                 } else {
423                                         /* we must initiate input */
424                                         dev_dbg(&dev->udev->dev,
425                                                 "%s : initiate input\n",
426                                                 __func__);
427                                         dev->read_urb_finished = 0;
428                                         spin_unlock_irqrestore(&dev->buflock, flags);
429 
430                                         usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
431                                                         usb_rcvintpipe(dev->udev,
432                                                                 dev->interrupt_in_endpoint->bEndpointAddress),
433                                                          dev->interrupt_in_buffer,
434                                                          usb_endpoint_maxp(dev->interrupt_in_endpoint),
435                                                          adu_interrupt_in_callback,
436                                                          dev,
437                                                          dev->interrupt_in_endpoint->bInterval);
438                                         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
439                                         if (retval) {
440                                                 dev->read_urb_finished = 1;
441                                                 if (retval == -ENOMEM) {
442                                                         retval = bytes_read ? bytes_read : -ENOMEM;
443                                                 }
444                                                 dev_dbg(&dev->udev->dev,
445                                                         "%s : submit failed\n",
446                                                         __func__);
447                                                 goto exit;
448                                         }
449                                 }
450 
451                                 /* we wait for I/O to complete */
452                                 set_current_state(TASK_INTERRUPTIBLE);
453                                 add_wait_queue(&dev->read_wait, &wait);
454                                 spin_lock_irqsave(&dev->buflock, flags);
455                                 if (!dev->read_urb_finished) {
456                                         spin_unlock_irqrestore(&dev->buflock, flags);
457                                         timeout = schedule_timeout(COMMAND_TIMEOUT);
458                                 } else {
459                                         spin_unlock_irqrestore(&dev->buflock, flags);
460                                         set_current_state(TASK_RUNNING);
461                                 }
462                                 remove_wait_queue(&dev->read_wait, &wait);
463 
464                                 if (timeout <= 0) {
465                                         dev_dbg(&dev->udev->dev,
466                                                 "%s : timeout\n", __func__);
467                                         retval = bytes_read ? bytes_read : -ETIMEDOUT;
468                                         goto exit;
469                                 }
470 
471                                 if (signal_pending(current)) {
472                                         dev_dbg(&dev->udev->dev,
473                                                 "%s : signal pending\n",
474                                                 __func__);
475                                         retval = bytes_read ? bytes_read : -EINTR;
476                                         goto exit;
477                                 }
478                         }
479                 }
480         }
481 
482         retval = bytes_read;
483         /* if the primary buffer is empty then use it */
484         spin_lock_irqsave(&dev->buflock, flags);
485         if (should_submit && dev->read_urb_finished) {
486                 dev->read_urb_finished = 0;
487                 spin_unlock_irqrestore(&dev->buflock, flags);
488                 usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
489                                  usb_rcvintpipe(dev->udev,
490                                         dev->interrupt_in_endpoint->bEndpointAddress),
491                                 dev->interrupt_in_buffer,
492                                 usb_endpoint_maxp(dev->interrupt_in_endpoint),
493                                 adu_interrupt_in_callback,
494                                 dev,
495                                 dev->interrupt_in_endpoint->bInterval);
496                 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
497                         dev->read_urb_finished = 1;
498                 /* we ignore failure */
499         } else {
500                 spin_unlock_irqrestore(&dev->buflock, flags);
501         }
502 
503 exit:
504         /* unlock the device */
505         mutex_unlock(&dev->mtx);
506 
507         return retval;
508 }
509 
510 static ssize_t adu_write(struct file *file, const __user char *buffer,
511                          size_t count, loff_t *ppos)
512 {
513         DECLARE_WAITQUEUE(waita, current);
514         struct adu_device *dev;
515         size_t bytes_written = 0;
516         size_t bytes_to_write;
517         size_t buffer_size;
518         unsigned long flags;
519         int retval;
520 
521         dev = file->private_data;
522 
523         retval = mutex_lock_interruptible(&dev->mtx);
524         if (retval)
525                 goto exit_nolock;
526 
527         /* verify that the device wasn't unplugged */
528         if (dev->udev == NULL) {
529                 retval = -ENODEV;
530                 pr_err("No device or device unplugged %d\n", retval);
531                 goto exit;
532         }
533 
534         /* verify that we actually have some data to write */
535         if (count == 0) {
536                 dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n",
537                         __func__);
538                 goto exit;
539         }
540 
541         while (count > 0) {
542                 add_wait_queue(&dev->write_wait, &waita);
543                 set_current_state(TASK_INTERRUPTIBLE);
544                 spin_lock_irqsave(&dev->buflock, flags);
545                 if (!dev->out_urb_finished) {
546                         spin_unlock_irqrestore(&dev->buflock, flags);
547 
548                         mutex_unlock(&dev->mtx);
549                         if (signal_pending(current)) {
550                                 dev_dbg(&dev->udev->dev, "%s : interrupted\n",
551                                         __func__);
552                                 set_current_state(TASK_RUNNING);
553                                 retval = -EINTR;
554                                 goto exit_onqueue;
555                         }
556                         if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
557                                 dev_dbg(&dev->udev->dev,
558                                         "%s - command timed out.\n", __func__);
559                                 retval = -ETIMEDOUT;
560                                 goto exit_onqueue;
561                         }
562                         remove_wait_queue(&dev->write_wait, &waita);
563                         retval = mutex_lock_interruptible(&dev->mtx);
564                         if (retval) {
565                                 retval = bytes_written ? bytes_written : retval;
566                                 goto exit_nolock;
567                         }
568 
569                         dev_dbg(&dev->udev->dev,
570                                 "%s : in progress, count = %Zd\n",
571                                 __func__, count);
572                 } else {
573                         spin_unlock_irqrestore(&dev->buflock, flags);
574                         set_current_state(TASK_RUNNING);
575                         remove_wait_queue(&dev->write_wait, &waita);
576                         dev_dbg(&dev->udev->dev, "%s : sending, count = %Zd\n",
577                                 __func__, count);
578 
579                         /* write the data into interrupt_out_buffer from userspace */
580                         buffer_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
581                         bytes_to_write = count > buffer_size ? buffer_size : count;
582                         dev_dbg(&dev->udev->dev,
583                                 "%s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd\n",
584                                 __func__, buffer_size, count, bytes_to_write);
585 
586                         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
587                                 retval = -EFAULT;
588                                 goto exit;
589                         }
590 
591                         /* send off the urb */
592                         usb_fill_int_urb(
593                                 dev->interrupt_out_urb,
594                                 dev->udev,
595                                 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
596                                 dev->interrupt_out_buffer,
597                                 bytes_to_write,
598                                 adu_interrupt_out_callback,
599                                 dev,
600                                 dev->interrupt_out_endpoint->bInterval);
601                         dev->interrupt_out_urb->actual_length = bytes_to_write;
602                         dev->out_urb_finished = 0;
603                         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
604                         if (retval < 0) {
605                                 dev->out_urb_finished = 1;
606                                 dev_err(&dev->udev->dev, "Couldn't submit "
607                                         "interrupt_out_urb %d\n", retval);
608                                 goto exit;
609                         }
610 
611                         buffer += bytes_to_write;
612                         count -= bytes_to_write;
613 
614                         bytes_written += bytes_to_write;
615                 }
616         }
617         mutex_unlock(&dev->mtx);
618         return bytes_written;
619 
620 exit:
621         mutex_unlock(&dev->mtx);
622 exit_nolock:
623         return retval;
624 
625 exit_onqueue:
626         remove_wait_queue(&dev->write_wait, &waita);
627         return retval;
628 }
629 
630 /* file operations needed when we register this driver */
631 static const struct file_operations adu_fops = {
632         .owner = THIS_MODULE,
633         .read  = adu_read,
634         .write = adu_write,
635         .open = adu_open,
636         .release = adu_release,
637         .llseek = noop_llseek,
638 };
639 
640 /*
641  * usb class driver info in order to get a minor number from the usb core,
642  * and to have the device registered with devfs and the driver core
643  */
644 static struct usb_class_driver adu_class = {
645         .name = "usb/adutux%d",
646         .fops = &adu_fops,
647         .minor_base = ADU_MINOR_BASE,
648 };
649 
650 /**
651  * adu_probe
652  *
653  * Called by the usb core when a new device is connected that it thinks
654  * this driver might be interested in.
655  */
656 static int adu_probe(struct usb_interface *interface,
657                      const struct usb_device_id *id)
658 {
659         struct usb_device *udev = interface_to_usbdev(interface);
660         struct adu_device *dev = NULL;
661         struct usb_host_interface *iface_desc;
662         struct usb_endpoint_descriptor *endpoint;
663         int retval = -ENODEV;
664         int in_end_size;
665         int out_end_size;
666         int i;
667 
668         if (udev == NULL) {
669                 dev_err(&interface->dev, "udev is NULL.\n");
670                 goto exit;
671         }
672 
673         /* allocate memory for our device state and initialize it */
674         dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
675         if (dev == NULL) {
676                 dev_err(&interface->dev, "Out of memory\n");
677                 retval = -ENOMEM;
678                 goto exit;
679         }
680 
681         mutex_init(&dev->mtx);
682         spin_lock_init(&dev->buflock);
683         dev->udev = udev;
684         init_waitqueue_head(&dev->read_wait);
685         init_waitqueue_head(&dev->write_wait);
686 
687         iface_desc = &interface->altsetting[0];
688 
689         /* set up the endpoint information */
690         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
691                 endpoint = &iface_desc->endpoint[i].desc;
692 
693                 if (usb_endpoint_is_int_in(endpoint))
694                         dev->interrupt_in_endpoint = endpoint;
695 
696                 if (usb_endpoint_is_int_out(endpoint))
697                         dev->interrupt_out_endpoint = endpoint;
698         }
699         if (dev->interrupt_in_endpoint == NULL) {
700                 dev_err(&interface->dev, "interrupt in endpoint not found\n");
701                 goto error;
702         }
703         if (dev->interrupt_out_endpoint == NULL) {
704                 dev_err(&interface->dev, "interrupt out endpoint not found\n");
705                 goto error;
706         }
707 
708         in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
709         out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
710 
711         dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
712         if (!dev->read_buffer_primary) {
713                 dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
714                 retval = -ENOMEM;
715                 goto error;
716         }
717 
718         /* debug code prime the buffer */
719         memset(dev->read_buffer_primary, 'a', in_end_size);
720         memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
721         memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
722         memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
723 
724         dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
725         if (!dev->read_buffer_secondary) {
726                 dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
727                 retval = -ENOMEM;
728                 goto error;
729         }
730 
731         /* debug code prime the buffer */
732         memset(dev->read_buffer_secondary, 'e', in_end_size);
733         memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
734         memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
735         memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
736 
737         dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
738         if (!dev->interrupt_in_buffer) {
739                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
740                 goto error;
741         }
742 
743         /* debug code prime the buffer */
744         memset(dev->interrupt_in_buffer, 'i', in_end_size);
745 
746         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
747         if (!dev->interrupt_in_urb) {
748                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
749                 goto error;
750         }
751         dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
752         if (!dev->interrupt_out_buffer) {
753                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
754                 goto error;
755         }
756         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
757         if (!dev->interrupt_out_urb) {
758                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
759                 goto error;
760         }
761 
762         if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
763                         sizeof(dev->serial_number))) {
764                 dev_err(&interface->dev, "Could not retrieve serial number\n");
765                 goto error;
766         }
767         dev_dbg(&interface->dev,"serial_number=%s", dev->serial_number);
768 
769         /* we can register the device now, as it is ready */
770         usb_set_intfdata(interface, dev);
771 
772         retval = usb_register_dev(interface, &adu_class);
773 
774         if (retval) {
775                 /* something prevented us from registering this driver */
776                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
777                 usb_set_intfdata(interface, NULL);
778                 goto error;
779         }
780 
781         dev->minor = interface->minor;
782 
783         /* let the user know what node this device is now attached to */
784         dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
785                  le16_to_cpu(udev->descriptor.idProduct), dev->serial_number,
786                  (dev->minor - ADU_MINOR_BASE));
787 exit:
788         return retval;
789 
790 error:
791         adu_delete(dev);
792         return retval;
793 }
794 
795 /**
796  * adu_disconnect
797  *
798  * Called by the usb core when the device is removed from the system.
799  */
800 static void adu_disconnect(struct usb_interface *interface)
801 {
802         struct adu_device *dev;
803         int minor;
804 
805         dev = usb_get_intfdata(interface);
806 
807         mutex_lock(&dev->mtx);  /* not interruptible */
808         dev->udev = NULL;       /* poison */
809         minor = dev->minor;
810         usb_deregister_dev(interface, &adu_class);
811         mutex_unlock(&dev->mtx);
812 
813         mutex_lock(&adutux_mutex);
814         usb_set_intfdata(interface, NULL);
815 
816         /* if the device is not opened, then we clean up right now */
817         dev_dbg(&dev->udev->dev, "%s : open count %d\n",
818                 __func__, dev->open_count);
819         if (!dev->open_count)
820                 adu_delete(dev);
821 
822         mutex_unlock(&adutux_mutex);
823 
824         dev_info(&interface->dev, "ADU device adutux%d now disconnected\n",
825                  (minor - ADU_MINOR_BASE));
826 }
827 
828 /* usb specific object needed to register this driver with the usb subsystem */
829 static struct usb_driver adu_driver = {
830         .name = "adutux",
831         .probe = adu_probe,
832         .disconnect = adu_disconnect,
833         .id_table = device_table,
834 };
835 
836 module_usb_driver(adu_driver);
837 
838 MODULE_AUTHOR(DRIVER_AUTHOR);
839 MODULE_DESCRIPTION(DRIVER_DESC);
840 MODULE_LICENSE("GPL");
841 

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