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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -03002 * USB Skeleton driver - 2.2
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, version 2.
9 *
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -030010 * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c
Alan Stern121e2872006-07-01 22:06:36 -040011 * but has been rewritten to be easier to read and use.
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 *
13 */
14
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/errno.h>
17#include <linux/init.h>
18#include <linux/slab.h>
19#include <linux/module.h>
20#include <linux/kref.h>
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -070021#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/usb.h>
Alan Stern121e2872006-07-01 22:06:36 -040023#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25
26/* Define these values to match your devices */
27#define USB_SKEL_VENDOR_ID 0xfff0
28#define USB_SKEL_PRODUCT_ID 0xfff0
29
30/* table of devices that work with this driver */
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -070031static struct usb_device_id skel_table[] = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
33 { } /* Terminating entry */
34};
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -030035MODULE_DEVICE_TABLE(usb, skel_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37
38/* Get a minor range for your devices from the usb maintainer */
39#define USB_SKEL_MINOR_BASE 192
40
Oliver Neukumff906512005-12-21 19:27:29 +010041/* our private defines. if this grows any larger, use your own .h file */
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -030042#define MAX_TRANSFER (PAGE_SIZE - 512)
Oliver Neukumba35e022007-03-01 14:31:02 +010043/* MAX_TRANSFER is chosen so that the VM is not stressed by
44 allocations > PAGE_SIZE and the number of packets in a page
45 is an integer 512 is the largest possible packet on EHCI */
Oliver Neukumff906512005-12-21 19:27:29 +010046#define WRITES_IN_FLIGHT 8
Oliver Neukumba35e022007-03-01 14:31:02 +010047/* arbitrarily chosen */
Oliver Neukumff906512005-12-21 19:27:29 +010048
Linus Torvalds1da177e2005-04-16 15:20:36 -070049/* Structure to hold all of our device specific stuff */
50struct usb_skel {
Oliver Neukumba35e022007-03-01 14:31:02 +010051 struct usb_device *udev; /* the usb device for this device */
52 struct usb_interface *interface; /* the interface for this device */
Oliver Neukumff906512005-12-21 19:27:29 +010053 struct semaphore limit_sem; /* limiting the number of writes in progress */
Oliver Neukum403dfb52007-05-25 13:42:56 +020054 struct usb_anchor submitted; /* in case we need to retract our submissions */
Oliver Neukume7389cc2009-09-09 17:06:53 +020055 struct urb *bulk_in_urb; /* the urb to read data with */
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -030056 unsigned char *bulk_in_buffer; /* the buffer to receive data */
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 size_t bulk_in_size; /* the size of the receive buffer */
Oliver Neukume7389cc2009-09-09 17:06:53 +020058 size_t bulk_in_filled; /* number of bytes in the buffer */
59 size_t bulk_in_copied; /* already copied to user space */
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */
61 __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */
Oliver Neukum403dfb52007-05-25 13:42:56 +020062 int errors; /* the last request tanked */
Oliver Neukum758f7e162007-06-11 14:55:08 +020063 int open_count; /* count the number of openers */
Oliver Neukume7389cc2009-09-09 17:06:53 +020064 bool ongoing_read; /* a read is going on */
65 bool processed_urb; /* indicates we haven't processed the urb */
Oliver Neukum403dfb52007-05-25 13:42:56 +020066 spinlock_t err_lock; /* lock for errors */
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 struct kref kref;
Alan Stern121e2872006-07-01 22:06:36 -040068 struct mutex io_mutex; /* synchronize I/O with disconnect */
Oliver Neukume7389cc2009-09-09 17:06:53 +020069 struct completion bulk_in_completion; /* to wait for an ongoing read */
Linus Torvalds1da177e2005-04-16 15:20:36 -070070};
71#define to_skel_dev(d) container_of(d, struct usb_skel, kref)
72
73static struct usb_driver skel_driver;
Oliver Neukum403dfb52007-05-25 13:42:56 +020074static void skel_draw_down(struct usb_skel *dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76static void skel_delete(struct kref *kref)
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -030077{
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 struct usb_skel *dev = to_skel_dev(kref);
79
Oliver Neukume7389cc2009-09-09 17:06:53 +020080 usb_free_urb(dev->bulk_in_urb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 usb_put_dev(dev->udev);
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -030082 kfree(dev->bulk_in_buffer);
83 kfree(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084}
85
86static int skel_open(struct inode *inode, struct file *file)
87{
88 struct usb_skel *dev;
89 struct usb_interface *interface;
90 int subminor;
91 int retval = 0;
92
93 subminor = iminor(inode);
94
95 interface = usb_find_interface(&skel_driver, subminor);
96 if (!interface) {
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -070097 err("%s - error, can't find device for minor %d",
Harvey Harrison441b62c2008-03-03 16:08:34 -080098 __func__, subminor);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 retval = -ENODEV;
100 goto exit;
101 }
102
103 dev = usb_get_intfdata(interface);
104 if (!dev) {
105 retval = -ENODEV;
106 goto exit;
107 }
108
109 /* increment our usage count for the device */
110 kref_get(&dev->kref);
111
Oliver Neukum758f7e162007-06-11 14:55:08 +0200112 /* lock the device to allow correctly handling errors
113 * in resumption */
114 mutex_lock(&dev->io_mutex);
115
116 if (!dev->open_count++) {
117 retval = usb_autopm_get_interface(interface);
118 if (retval) {
119 dev->open_count--;
120 mutex_unlock(&dev->io_mutex);
121 kref_put(&dev->kref, skel_delete);
122 goto exit;
123 }
124 } /* else { //uncomment this block if you want exclusive open
125 retval = -EBUSY;
126 dev->open_count--;
127 mutex_unlock(&dev->io_mutex);
Oliver Neukum5b064702007-02-08 15:42:53 +0100128 kref_put(&dev->kref, skel_delete);
129 goto exit;
Oliver Neukum758f7e162007-06-11 14:55:08 +0200130 } */
131 /* prevent the device from being autosuspended */
Oliver Neukum5b064702007-02-08 15:42:53 +0100132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 /* save our object in the file's private structure */
134 file->private_data = dev;
Mark Grossf7294052007-09-24 09:28:14 -0700135 mutex_unlock(&dev->io_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137exit:
138 return retval;
139}
140
141static int skel_release(struct inode *inode, struct file *file)
142{
143 struct usb_skel *dev;
144
145 dev = (struct usb_skel *)file->private_data;
146 if (dev == NULL)
147 return -ENODEV;
148
Alan Stern01d883d2006-08-30 15:47:18 -0400149 /* allow the device to be autosuspended */
150 mutex_lock(&dev->io_mutex);
Oliver Neukum758f7e162007-06-11 14:55:08 +0200151 if (!--dev->open_count && dev->interface)
Alan Stern01d883d2006-08-30 15:47:18 -0400152 usb_autopm_put_interface(dev->interface);
153 mutex_unlock(&dev->io_mutex);
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 /* decrement the count on our device */
156 kref_put(&dev->kref, skel_delete);
157 return 0;
158}
159
Oliver Neukum403dfb52007-05-25 13:42:56 +0200160static int skel_flush(struct file *file, fl_owner_t id)
161{
162 struct usb_skel *dev;
163 int res;
164
165 dev = (struct usb_skel *)file->private_data;
166 if (dev == NULL)
167 return -ENODEV;
168
169 /* wait for io to stop */
170 mutex_lock(&dev->io_mutex);
171 skel_draw_down(dev);
172
173 /* read out errors, leave subsequent opens a clean slate */
174 spin_lock_irq(&dev->err_lock);
175 res = dev->errors ? (dev->errors == -EPIPE ? -EPIPE : -EIO) : 0;
176 dev->errors = 0;
177 spin_unlock_irq(&dev->err_lock);
178
179 mutex_unlock(&dev->io_mutex);
180
181 return res;
182}
183
Oliver Neukume7389cc2009-09-09 17:06:53 +0200184static void skel_read_bulk_callback(struct urb *urb)
185{
186 struct usb_skel *dev;
187
188 dev = urb->context;
189
190 spin_lock(&dev->err_lock);
191 /* sync/async unlink faults aren't errors */
192 if (urb->status) {
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700193 if (!(urb->status == -ENOENT ||
Oliver Neukume7389cc2009-09-09 17:06:53 +0200194 urb->status == -ECONNRESET ||
195 urb->status == -ESHUTDOWN))
196 err("%s - nonzero write bulk status received: %d",
197 __func__, urb->status);
198
199 dev->errors = urb->status;
200 } else {
201 dev->bulk_in_filled = urb->actual_length;
202 }
203 dev->ongoing_read = 0;
204 spin_unlock(&dev->err_lock);
205
206 complete(&dev->bulk_in_completion);
207}
208
209static int skel_do_read_io(struct usb_skel *dev, size_t count)
210{
211 int rv;
212
213 /* prepare a read */
214 usb_fill_bulk_urb(dev->bulk_in_urb,
215 dev->udev,
216 usb_rcvbulkpipe(dev->udev,
217 dev->bulk_in_endpointAddr),
218 dev->bulk_in_buffer,
219 min(dev->bulk_in_size, count),
220 skel_read_bulk_callback,
221 dev);
222 /* tell everybody to leave the URB alone */
223 spin_lock_irq(&dev->err_lock);
224 dev->ongoing_read = 1;
225 spin_unlock_irq(&dev->err_lock);
226
227 /* do it */
228 rv = usb_submit_urb(dev->bulk_in_urb, GFP_KERNEL);
229 if (rv < 0) {
230 err("%s - failed submitting read urb, error %d",
231 __func__, rv);
232 dev->bulk_in_filled = 0;
233 rv = (rv == -ENOMEM) ? rv : -EIO;
234 spin_lock_irq(&dev->err_lock);
235 dev->ongoing_read = 0;
236 spin_unlock_irq(&dev->err_lock);
237 }
238
239 return rv;
240}
241
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700242static ssize_t skel_read(struct file *file, char *buffer, size_t count,
243 loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244{
245 struct usb_skel *dev;
Oliver Neukume7389cc2009-09-09 17:06:53 +0200246 int rv;
247 bool ongoing_io;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249 dev = (struct usb_skel *)file->private_data;
Alan Stern121e2872006-07-01 22:06:36 -0400250
Oliver Neukume7389cc2009-09-09 17:06:53 +0200251 /* if we cannot read at all, return EOF */
252 if (!dev->bulk_in_urb || !count)
253 return 0;
254
255 /* no concurrent readers */
256 rv = mutex_lock_interruptible(&dev->io_mutex);
257 if (rv < 0)
258 return rv;
259
Alan Stern121e2872006-07-01 22:06:36 -0400260 if (!dev->interface) { /* disconnect() was called */
Oliver Neukume7389cc2009-09-09 17:06:53 +0200261 rv = -ENODEV;
Alan Stern121e2872006-07-01 22:06:36 -0400262 goto exit;
263 }
264
Oliver Neukume7389cc2009-09-09 17:06:53 +0200265 /* if IO is under way, we must not touch things */
266retry:
267 spin_lock_irq(&dev->err_lock);
268 ongoing_io = dev->ongoing_read;
269 spin_unlock_irq(&dev->err_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
Oliver Neukume7389cc2009-09-09 17:06:53 +0200271 if (ongoing_io) {
Oliver Neukum8cd01662009-09-09 17:08:50 +0200272 /* nonblocking IO shall not wait */
273 if (file->f_flags & O_NONBLOCK) {
274 rv = -EAGAIN;
275 goto exit;
276 }
Oliver Neukume7389cc2009-09-09 17:06:53 +0200277 /*
278 * IO may take forever
279 * hence wait in an interruptible state
280 */
281 rv = wait_for_completion_interruptible(&dev->bulk_in_completion);
282 if (rv < 0)
283 goto exit;
284 /*
285 * by waiting we also semiprocessed the urb
286 * we must finish now
287 */
288 dev->bulk_in_copied = 0;
289 dev->processed_urb = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 }
291
Oliver Neukume7389cc2009-09-09 17:06:53 +0200292 if (!dev->processed_urb) {
293 /*
294 * the URB hasn't been processed
295 * do it now
296 */
297 wait_for_completion(&dev->bulk_in_completion);
298 dev->bulk_in_copied = 0;
299 dev->processed_urb = 1;
300 }
301
302 /* errors must be reported */
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700303 rv = dev->errors;
304 if (rv < 0) {
Oliver Neukume7389cc2009-09-09 17:06:53 +0200305 /* any error is reported once */
306 dev->errors = 0;
307 /* to preserve notifications about reset */
308 rv = (rv == -EPIPE) ? rv : -EIO;
309 /* no data to deliver */
310 dev->bulk_in_filled = 0;
311 /* report it */
312 goto exit;
313 }
314
315 /*
316 * if the buffer is filled we may satisfy the read
317 * else we need to start IO
318 */
319
320 if (dev->bulk_in_filled) {
321 /* we had read data */
322 size_t available = dev->bulk_in_filled - dev->bulk_in_copied;
323 size_t chunk = min(available, count);
324
325 if (!available) {
326 /*
327 * all data has been used
328 * actual IO needs to be done
329 */
330 rv = skel_do_read_io(dev, count);
331 if (rv < 0)
332 goto exit;
333 else
334 goto retry;
335 }
336 /*
337 * data is available
338 * chunk tells us how much shall be copied
339 */
340
341 if (copy_to_user(buffer,
342 dev->bulk_in_buffer + dev->bulk_in_copied,
343 chunk))
344 rv = -EFAULT;
345 else
346 rv = chunk;
347
348 dev->bulk_in_copied += chunk;
349
350 /*
351 * if we are asked for more than we have,
352 * we start IO but don't wait
353 */
354 if (available < count)
355 skel_do_read_io(dev, count - chunk);
356 } else {
357 /* no data in the buffer */
358 rv = skel_do_read_io(dev, count);
359 if (rv < 0)
360 goto exit;
Julia Lawall4de84052009-09-19 09:13:43 +0200361 else if (!(file->f_flags & O_NONBLOCK))
Oliver Neukume7389cc2009-09-09 17:06:53 +0200362 goto retry;
Oliver Neukum8cd01662009-09-09 17:08:50 +0200363 rv = -EAGAIN;
Oliver Neukume7389cc2009-09-09 17:06:53 +0200364 }
Alan Stern121e2872006-07-01 22:06:36 -0400365exit:
366 mutex_unlock(&dev->io_mutex);
Oliver Neukume7389cc2009-09-09 17:06:53 +0200367 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368}
369
David Howells7d12e782006-10-05 14:55:46 +0100370static void skel_write_bulk_callback(struct urb *urb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371{
372 struct usb_skel *dev;
373
Ming Leicdc97792008-02-24 18:41:47 +0800374 dev = urb->context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
376 /* sync/async unlink faults aren't errors */
Oliver Neukum403dfb52007-05-25 13:42:56 +0200377 if (urb->status) {
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700378 if (!(urb->status == -ENOENT ||
Oliver Neukum403dfb52007-05-25 13:42:56 +0200379 urb->status == -ECONNRESET ||
380 urb->status == -ESHUTDOWN))
381 err("%s - nonzero write bulk status received: %d",
Harvey Harrison441b62c2008-03-03 16:08:34 -0800382 __func__, urb->status);
Oliver Neukum403dfb52007-05-25 13:42:56 +0200383
384 spin_lock(&dev->err_lock);
385 dev->errors = urb->status;
386 spin_unlock(&dev->err_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 }
388
389 /* free up our allocated buffer */
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -0300390 usb_buffer_free(urb->dev, urb->transfer_buffer_length,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 urb->transfer_buffer, urb->transfer_dma);
Oliver Neukumff906512005-12-21 19:27:29 +0100392 up(&dev->limit_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393}
394
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700395static ssize_t skel_write(struct file *file, const char *user_buffer,
396 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397{
398 struct usb_skel *dev;
399 int retval = 0;
400 struct urb *urb = NULL;
401 char *buf = NULL;
Sam Bishopc8dd7702005-12-22 17:11:02 -0700402 size_t writesize = min(count, (size_t)MAX_TRANSFER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
404 dev = (struct usb_skel *)file->private_data;
405
406 /* verify that we actually have some data to write */
407 if (count == 0)
408 goto exit;
409
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700410 /*
411 * limit the number of URBs in flight to stop a user from using up all
412 * RAM
413 */
Julia Lawall4de84052009-09-19 09:13:43 +0200414 if (!(file->f_flags & O_NONBLOCK)) {
Oliver Neukum79819982009-09-09 10:23:35 +0200415 if (down_interruptible(&dev->limit_sem)) {
416 retval = -ERESTARTSYS;
417 goto exit;
418 }
419 } else {
420 if (down_trylock(&dev->limit_sem)) {
421 retval = -EAGAIN;
422 goto exit;
423 }
Sam Bishopc8dd7702005-12-22 17:11:02 -0700424 }
Oliver Neukumff906512005-12-21 19:27:29 +0100425
Oliver Neukum403dfb52007-05-25 13:42:56 +0200426 spin_lock_irq(&dev->err_lock);
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700427 retval = dev->errors;
428 if (retval < 0) {
Oliver Neukum403dfb52007-05-25 13:42:56 +0200429 /* any error is reported once */
430 dev->errors = 0;
431 /* to preserve notifications about reset */
432 retval = (retval == -EPIPE) ? retval : -EIO;
433 }
434 spin_unlock_irq(&dev->err_lock);
435 if (retval < 0)
436 goto error;
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 /* create a urb, and a buffer for it, and copy the data to the urb */
439 urb = usb_alloc_urb(0, GFP_KERNEL);
440 if (!urb) {
441 retval = -ENOMEM;
442 goto error;
443 }
444
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700445 buf = usb_buffer_alloc(dev->udev, writesize, GFP_KERNEL,
446 &urb->transfer_dma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 if (!buf) {
448 retval = -ENOMEM;
449 goto error;
450 }
451
Oliver Neukumff906512005-12-21 19:27:29 +0100452 if (copy_from_user(buf, user_buffer, writesize)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 retval = -EFAULT;
454 goto error;
455 }
456
Oliver Neukumba35e022007-03-01 14:31:02 +0100457 /* this lock makes sure we don't submit URBs to gone devices */
458 mutex_lock(&dev->io_mutex);
459 if (!dev->interface) { /* disconnect() was called */
460 mutex_unlock(&dev->io_mutex);
461 retval = -ENODEV;
462 goto error;
463 }
464
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 /* initialize the urb properly */
466 usb_fill_bulk_urb(urb, dev->udev,
467 usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
Oliver Neukumff906512005-12-21 19:27:29 +0100468 buf, writesize, skel_write_bulk_callback, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
Oliver Neukum403dfb52007-05-25 13:42:56 +0200470 usb_anchor_urb(urb, &dev->submitted);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
472 /* send the data out the bulk port */
473 retval = usb_submit_urb(urb, GFP_KERNEL);
Oliver Neukumba35e022007-03-01 14:31:02 +0100474 mutex_unlock(&dev->io_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 if (retval) {
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700476 err("%s - failed submitting write urb, error %d", __func__,
477 retval);
Oliver Neukum403dfb52007-05-25 13:42:56 +0200478 goto error_unanchor;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 }
480
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700481 /*
482 * release our reference to this urb, the USB core will eventually free
483 * it entirely
484 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 usb_free_urb(urb);
486
Oliver Neukumba35e022007-03-01 14:31:02 +0100487
Oliver Neukumff906512005-12-21 19:27:29 +0100488 return writesize;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
Oliver Neukum403dfb52007-05-25 13:42:56 +0200490error_unanchor:
491 usb_unanchor_urb(urb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492error:
Alan Stern121e2872006-07-01 22:06:36 -0400493 if (urb) {
494 usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma);
495 usb_free_urb(urb);
496 }
Oliver Neukumff906512005-12-21 19:27:29 +0100497 up(&dev->limit_sem);
Alan Stern121e2872006-07-01 22:06:36 -0400498
499exit:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 return retval;
501}
502
Luiz Fernando N. Capitulino066202d2006-08-05 20:37:11 -0300503static const struct file_operations skel_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 .owner = THIS_MODULE,
505 .read = skel_read,
506 .write = skel_write,
507 .open = skel_open,
508 .release = skel_release,
Oliver Neukum403dfb52007-05-25 13:42:56 +0200509 .flush = skel_flush,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510};
511
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -0300512/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 * usb class driver info in order to get a minor number from the usb core,
Greg Kroah-Hartman595b14c2006-01-18 17:36:58 -0500514 * and to have the device registered with the driver core
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 */
516static struct usb_class_driver skel_class = {
Greg Kroah-Hartmand6e5bcf2005-06-20 21:15:16 -0700517 .name = "skel%d",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 .fops = &skel_fops,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 .minor_base = USB_SKEL_MINOR_BASE,
520};
521
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700522static int skel_probe(struct usb_interface *interface,
523 const struct usb_device_id *id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524{
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -0300525 struct usb_skel *dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 struct usb_host_interface *iface_desc;
527 struct usb_endpoint_descriptor *endpoint;
528 size_t buffer_size;
529 int i;
530 int retval = -ENOMEM;
531
532 /* allocate memory for our device state and initialize it */
Oliver Neukumff906512005-12-21 19:27:29 +0100533 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -0300534 if (!dev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 err("Out of memory");
536 goto error;
537 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 kref_init(&dev->kref);
Oliver Neukumff906512005-12-21 19:27:29 +0100539 sema_init(&dev->limit_sem, WRITES_IN_FLIGHT);
Alan Stern121e2872006-07-01 22:06:36 -0400540 mutex_init(&dev->io_mutex);
Oliver Neukum403dfb52007-05-25 13:42:56 +0200541 spin_lock_init(&dev->err_lock);
542 init_usb_anchor(&dev->submitted);
Oliver Neukume7389cc2009-09-09 17:06:53 +0200543 init_completion(&dev->bulk_in_completion);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544
545 dev->udev = usb_get_dev(interface_to_usbdev(interface));
546 dev->interface = interface;
547
548 /* set up the endpoint information */
549 /* use only the first bulk-in and bulk-out endpoints */
550 iface_desc = interface->cur_altsetting;
551 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
552 endpoint = &iface_desc->endpoint[i].desc;
553
554 if (!dev->bulk_in_endpointAddr &&
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -0300555 usb_endpoint_is_bulk_in(endpoint)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 /* we found a bulk in endpoint */
557 buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
558 dev->bulk_in_size = buffer_size;
559 dev->bulk_in_endpointAddr = endpoint->bEndpointAddress;
560 dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);
561 if (!dev->bulk_in_buffer) {
562 err("Could not allocate bulk_in_buffer");
563 goto error;
564 }
Oliver Neukume7389cc2009-09-09 17:06:53 +0200565 dev->bulk_in_urb = usb_alloc_urb(0, GFP_KERNEL);
566 if (!dev->bulk_in_urb) {
567 err("Could not allocate bulk_in_urb");
568 goto error;
569 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 }
571
572 if (!dev->bulk_out_endpointAddr &&
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -0300573 usb_endpoint_is_bulk_out(endpoint)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 /* we found a bulk out endpoint */
575 dev->bulk_out_endpointAddr = endpoint->bEndpointAddress;
576 }
577 }
578 if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) {
579 err("Could not find both bulk-in and bulk-out endpoints");
580 goto error;
581 }
582
583 /* save our data pointer in this interface device */
584 usb_set_intfdata(interface, dev);
585
586 /* we can register the device now, as it is ready */
587 retval = usb_register_dev(interface, &skel_class);
588 if (retval) {
589 /* something prevented us from registering this driver */
590 err("Not able to get a minor for this device.");
591 usb_set_intfdata(interface, NULL);
592 goto error;
593 }
594
595 /* let the user know what node this device is now attached to */
Matt Kraaia5f5ea22009-02-06 19:38:51 -0800596 dev_info(&interface->dev,
597 "USB Skeleton device now attached to USBSkel-%d",
598 interface->minor);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 return 0;
600
601error:
602 if (dev)
Oliver Neukumba35e022007-03-01 14:31:02 +0100603 /* this frees allocated memory */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 kref_put(&dev->kref, skel_delete);
605 return retval;
606}
607
608static void skel_disconnect(struct usb_interface *interface)
609{
610 struct usb_skel *dev;
611 int minor = interface->minor;
612
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 dev = usb_get_intfdata(interface);
614 usb_set_intfdata(interface, NULL);
615
616 /* give back our minor */
617 usb_deregister_dev(interface, &skel_class);
618
Alan Stern121e2872006-07-01 22:06:36 -0400619 /* prevent more I/O from starting */
620 mutex_lock(&dev->io_mutex);
621 dev->interface = NULL;
622 mutex_unlock(&dev->io_mutex);
623
Oliver Neukume73c7242007-06-11 14:54:02 +0200624 usb_kill_anchored_urbs(&dev->submitted);
625
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 /* decrement our usage count */
627 kref_put(&dev->kref, skel_delete);
628
Matt Kraaia5f5ea22009-02-06 19:38:51 -0800629 dev_info(&interface->dev, "USB Skeleton #%d now disconnected", minor);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630}
631
Oliver Neukum403dfb52007-05-25 13:42:56 +0200632static void skel_draw_down(struct usb_skel *dev)
633{
634 int time;
635
636 time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
637 if (!time)
638 usb_kill_anchored_urbs(&dev->submitted);
Oliver Neukume7389cc2009-09-09 17:06:53 +0200639 usb_kill_urb(dev->bulk_in_urb);
Oliver Neukum403dfb52007-05-25 13:42:56 +0200640}
641
Oliver Neukum758f7e162007-06-11 14:55:08 +0200642static int skel_suspend(struct usb_interface *intf, pm_message_t message)
643{
644 struct usb_skel *dev = usb_get_intfdata(intf);
645
646 if (!dev)
647 return 0;
648 skel_draw_down(dev);
649 return 0;
650}
651
Greg Kroah-Hartman3ae9da12009-09-11 16:07:30 -0700652static int skel_resume(struct usb_interface *intf)
Oliver Neukum758f7e162007-06-11 14:55:08 +0200653{
654 return 0;
655}
656
Oliver Neukum87d093e2007-06-11 14:55:51 +0200657static int skel_pre_reset(struct usb_interface *intf)
658{
659 struct usb_skel *dev = usb_get_intfdata(intf);
660
661 mutex_lock(&dev->io_mutex);
662 skel_draw_down(dev);
663
664 return 0;
665}
666
667static int skel_post_reset(struct usb_interface *intf)
668{
669 struct usb_skel *dev = usb_get_intfdata(intf);
670
671 /* we are sure no URBs are active - no locking needed */
672 dev->errors = -EPIPE;
673 mutex_unlock(&dev->io_mutex);
674
675 return 0;
676}
677
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678static struct usb_driver skel_driver = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 .name = "skeleton",
680 .probe = skel_probe,
681 .disconnect = skel_disconnect,
Oliver Neukum758f7e162007-06-11 14:55:08 +0200682 .suspend = skel_suspend,
683 .resume = skel_resume,
Oliver Neukum87d093e2007-06-11 14:55:51 +0200684 .pre_reset = skel_pre_reset,
685 .post_reset = skel_post_reset,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 .id_table = skel_table,
Oliver Neukumba35e022007-03-01 14:31:02 +0100687 .supports_autosuspend = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688};
689
690static int __init usb_skel_init(void)
691{
692 int result;
693
694 /* register this driver with the USB subsystem */
695 result = usb_register(&skel_driver);
696 if (result)
697 err("usb_register failed. Error number %d", result);
698
699 return result;
700}
701
702static void __exit usb_skel_exit(void)
703{
704 /* deregister this driver with the USB subsystem */
705 usb_deregister(&skel_driver);
706}
707
Luiz Fernando N. Capitulinoc0704542006-08-14 22:44:29 -0300708module_init(usb_skel_init);
709module_exit(usb_skel_exit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710
711MODULE_LICENSE("GPL");