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814a8d50 AP |
1 | /* |
2 | * spidev.c -- simple synchronous userspace interface to SPI devices | |
3 | * | |
4 | * Copyright (C) 2006 SWAPP | |
5 | * Andrea Paterniani <a.paterniani@swapp-eng.it> | |
6 | * Copyright (C) 2007 David Brownell (simplification, cleanup) | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | */ | |
22 | ||
23 | #include <linux/init.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/ioctl.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/device.h> | |
28 | #include <linux/list.h> | |
29 | #include <linux/errno.h> | |
30 | #include <linux/mutex.h> | |
31 | #include <linux/slab.h> | |
32 | ||
33 | #include <linux/spi/spi.h> | |
34 | #include <linux/spi/spidev.h> | |
35 | ||
36 | #include <asm/uaccess.h> | |
37 | ||
38 | ||
39 | /* | |
40 | * This supports acccess to SPI devices using normal userspace I/O calls. | |
41 | * Note that while traditional UNIX/POSIX I/O semantics are half duplex, | |
42 | * and often mask message boundaries, full SPI support requires full duplex | |
43 | * transfers. There are several kinds of of internal message boundaries to | |
44 | * handle chipselect management and other protocol options. | |
45 | * | |
46 | * SPI has a character major number assigned. We allocate minor numbers | |
47 | * dynamically using a bitmask. You must use hotplug tools, such as udev | |
48 | * (or mdev with busybox) to create and destroy the /dev/spidevB.C device | |
49 | * nodes, since there is no fixed association of minor numbers with any | |
50 | * particular SPI bus or device. | |
51 | */ | |
52 | #define SPIDEV_MAJOR 153 /* assigned */ | |
53 | #define N_SPI_MINORS 32 /* ... up to 256 */ | |
54 | ||
55 | static unsigned long minors[N_SPI_MINORS / BITS_PER_LONG]; | |
56 | ||
57 | ||
6f166e38 AV |
58 | /* Bit masks for spi_device.mode management. Note that incorrect |
59 | * settings for CS_HIGH and 3WIRE can cause *lots* of trouble for other | |
60 | * devices on a shared bus: CS_HIGH, because this device will be | |
61 | * active when it shouldn't be; 3WIRE, because when active it won't | |
62 | * behave as it should. | |
63 | * | |
64 | * REVISIT should changing those two modes be privileged? | |
65 | */ | |
66 | #define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \ | |
67 | | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP) | |
814a8d50 AP |
68 | |
69 | struct spidev_data { | |
70 | struct device dev; | |
71 | struct spi_device *spi; | |
72 | struct list_head device_entry; | |
73 | ||
74 | struct mutex buf_lock; | |
75 | unsigned users; | |
76 | u8 *buffer; | |
77 | }; | |
78 | ||
79 | static LIST_HEAD(device_list); | |
80 | static DEFINE_MUTEX(device_list_lock); | |
81 | ||
82 | static unsigned bufsiz = 4096; | |
83 | module_param(bufsiz, uint, S_IRUGO); | |
84 | MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); | |
85 | ||
86 | /*-------------------------------------------------------------------------*/ | |
87 | ||
88 | /* Read-only message with current device setup */ | |
89 | static ssize_t | |
90 | spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) | |
91 | { | |
92 | struct spidev_data *spidev; | |
93 | struct spi_device *spi; | |
94 | ssize_t status = 0; | |
95 | ||
96 | /* chipselect only toggles at start or end of operation */ | |
97 | if (count > bufsiz) | |
98 | return -EMSGSIZE; | |
99 | ||
100 | spidev = filp->private_data; | |
101 | spi = spidev->spi; | |
102 | ||
103 | mutex_lock(&spidev->buf_lock); | |
104 | status = spi_read(spi, spidev->buffer, count); | |
105 | if (status == 0) { | |
106 | unsigned long missing; | |
107 | ||
108 | missing = copy_to_user(buf, spidev->buffer, count); | |
109 | if (count && missing == count) | |
110 | status = -EFAULT; | |
111 | else | |
112 | status = count - missing; | |
113 | } | |
114 | mutex_unlock(&spidev->buf_lock); | |
115 | ||
116 | return status; | |
117 | } | |
118 | ||
119 | /* Write-only message with current device setup */ | |
120 | static ssize_t | |
121 | spidev_write(struct file *filp, const char __user *buf, | |
122 | size_t count, loff_t *f_pos) | |
123 | { | |
124 | struct spidev_data *spidev; | |
125 | struct spi_device *spi; | |
126 | ssize_t status = 0; | |
127 | unsigned long missing; | |
128 | ||
129 | /* chipselect only toggles at start or end of operation */ | |
130 | if (count > bufsiz) | |
131 | return -EMSGSIZE; | |
132 | ||
133 | spidev = filp->private_data; | |
134 | spi = spidev->spi; | |
135 | ||
136 | mutex_lock(&spidev->buf_lock); | |
137 | missing = copy_from_user(spidev->buffer, buf, count); | |
138 | if (missing == 0) { | |
139 | status = spi_write(spi, spidev->buffer, count); | |
140 | if (status == 0) | |
141 | status = count; | |
142 | } else | |
143 | status = -EFAULT; | |
144 | mutex_unlock(&spidev->buf_lock); | |
145 | ||
146 | return status; | |
147 | } | |
148 | ||
149 | static int spidev_message(struct spidev_data *spidev, | |
150 | struct spi_ioc_transfer *u_xfers, unsigned n_xfers) | |
151 | { | |
152 | struct spi_message msg; | |
153 | struct spi_transfer *k_xfers; | |
154 | struct spi_transfer *k_tmp; | |
155 | struct spi_ioc_transfer *u_tmp; | |
156 | struct spi_device *spi = spidev->spi; | |
157 | unsigned n, total; | |
158 | u8 *buf; | |
159 | int status = -EFAULT; | |
160 | ||
161 | spi_message_init(&msg); | |
162 | k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL); | |
163 | if (k_xfers == NULL) | |
164 | return -ENOMEM; | |
165 | ||
166 | /* Construct spi_message, copying any tx data to bounce buffer. | |
167 | * We walk the array of user-provided transfers, using each one | |
168 | * to initialize a kernel version of the same transfer. | |
169 | */ | |
170 | mutex_lock(&spidev->buf_lock); | |
171 | buf = spidev->buffer; | |
172 | total = 0; | |
173 | for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; | |
174 | n; | |
175 | n--, k_tmp++, u_tmp++) { | |
176 | k_tmp->len = u_tmp->len; | |
177 | ||
da90fa8f DP |
178 | total += k_tmp->len; |
179 | if (total > bufsiz) { | |
180 | status = -EMSGSIZE; | |
181 | goto done; | |
182 | } | |
183 | ||
814a8d50 AP |
184 | if (u_tmp->rx_buf) { |
185 | k_tmp->rx_buf = buf; | |
96ddbf50 | 186 | if (!access_ok(VERIFY_WRITE, (u8 __user *) |
142956af | 187 | (uintptr_t) u_tmp->rx_buf, |
96ddbf50 | 188 | u_tmp->len)) |
814a8d50 AP |
189 | goto done; |
190 | } | |
191 | if (u_tmp->tx_buf) { | |
192 | k_tmp->tx_buf = buf; | |
4917d927 | 193 | if (copy_from_user(buf, (const u8 __user *) |
142956af | 194 | (uintptr_t) u_tmp->tx_buf, |
814a8d50 AP |
195 | u_tmp->len)) |
196 | goto done; | |
197 | } | |
814a8d50 AP |
198 | buf += k_tmp->len; |
199 | ||
200 | k_tmp->cs_change = !!u_tmp->cs_change; | |
201 | k_tmp->bits_per_word = u_tmp->bits_per_word; | |
202 | k_tmp->delay_usecs = u_tmp->delay_usecs; | |
203 | k_tmp->speed_hz = u_tmp->speed_hz; | |
204 | #ifdef VERBOSE | |
205 | dev_dbg(&spi->dev, | |
206 | " xfer len %zd %s%s%s%dbits %u usec %uHz\n", | |
207 | u_tmp->len, | |
208 | u_tmp->rx_buf ? "rx " : "", | |
209 | u_tmp->tx_buf ? "tx " : "", | |
210 | u_tmp->cs_change ? "cs " : "", | |
211 | u_tmp->bits_per_word ? : spi->bits_per_word, | |
212 | u_tmp->delay_usecs, | |
213 | u_tmp->speed_hz ? : spi->max_speed_hz); | |
214 | #endif | |
215 | spi_message_add_tail(k_tmp, &msg); | |
216 | } | |
217 | ||
218 | status = spi_sync(spi, &msg); | |
219 | if (status < 0) | |
220 | goto done; | |
221 | ||
222 | /* copy any rx data out of bounce buffer */ | |
223 | buf = spidev->buffer; | |
224 | for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { | |
225 | if (u_tmp->rx_buf) { | |
4917d927 | 226 | if (__copy_to_user((u8 __user *) |
142956af | 227 | (uintptr_t) u_tmp->rx_buf, buf, |
814a8d50 AP |
228 | u_tmp->len)) { |
229 | status = -EFAULT; | |
230 | goto done; | |
231 | } | |
232 | } | |
233 | buf += u_tmp->len; | |
234 | } | |
235 | status = total; | |
236 | ||
237 | done: | |
238 | mutex_unlock(&spidev->buf_lock); | |
239 | kfree(k_xfers); | |
240 | return status; | |
241 | } | |
242 | ||
243 | static int | |
244 | spidev_ioctl(struct inode *inode, struct file *filp, | |
245 | unsigned int cmd, unsigned long arg) | |
246 | { | |
247 | int err = 0; | |
248 | int retval = 0; | |
249 | struct spidev_data *spidev; | |
250 | struct spi_device *spi; | |
251 | u32 tmp; | |
252 | unsigned n_ioc; | |
253 | struct spi_ioc_transfer *ioc; | |
254 | ||
255 | /* Check type and command number */ | |
256 | if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC) | |
257 | return -ENOTTY; | |
258 | ||
259 | /* Check access direction once here; don't repeat below. | |
260 | * IOC_DIR is from the user perspective, while access_ok is | |
261 | * from the kernel perspective; so they look reversed. | |
262 | */ | |
263 | if (_IOC_DIR(cmd) & _IOC_READ) | |
264 | err = !access_ok(VERIFY_WRITE, | |
265 | (void __user *)arg, _IOC_SIZE(cmd)); | |
266 | if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE) | |
267 | err = !access_ok(VERIFY_READ, | |
268 | (void __user *)arg, _IOC_SIZE(cmd)); | |
269 | if (err) | |
270 | return -EFAULT; | |
271 | ||
272 | spidev = filp->private_data; | |
273 | spi = spidev->spi; | |
274 | ||
275 | switch (cmd) { | |
276 | /* read requests */ | |
277 | case SPI_IOC_RD_MODE: | |
278 | retval = __put_user(spi->mode & SPI_MODE_MASK, | |
279 | (__u8 __user *)arg); | |
280 | break; | |
281 | case SPI_IOC_RD_LSB_FIRST: | |
282 | retval = __put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0, | |
283 | (__u8 __user *)arg); | |
284 | break; | |
285 | case SPI_IOC_RD_BITS_PER_WORD: | |
286 | retval = __put_user(spi->bits_per_word, (__u8 __user *)arg); | |
287 | break; | |
288 | case SPI_IOC_RD_MAX_SPEED_HZ: | |
289 | retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg); | |
290 | break; | |
291 | ||
292 | /* write requests */ | |
293 | case SPI_IOC_WR_MODE: | |
294 | retval = __get_user(tmp, (u8 __user *)arg); | |
295 | if (retval == 0) { | |
296 | u8 save = spi->mode; | |
297 | ||
298 | if (tmp & ~SPI_MODE_MASK) { | |
299 | retval = -EINVAL; | |
300 | break; | |
301 | } | |
302 | ||
303 | tmp |= spi->mode & ~SPI_MODE_MASK; | |
304 | spi->mode = (u8)tmp; | |
305 | retval = spi_setup(spi); | |
306 | if (retval < 0) | |
307 | spi->mode = save; | |
308 | else | |
309 | dev_dbg(&spi->dev, "spi mode %02x\n", tmp); | |
310 | } | |
311 | break; | |
312 | case SPI_IOC_WR_LSB_FIRST: | |
313 | retval = __get_user(tmp, (__u8 __user *)arg); | |
314 | if (retval == 0) { | |
315 | u8 save = spi->mode; | |
316 | ||
317 | if (tmp) | |
318 | spi->mode |= SPI_LSB_FIRST; | |
319 | else | |
320 | spi->mode &= ~SPI_LSB_FIRST; | |
321 | retval = spi_setup(spi); | |
322 | if (retval < 0) | |
323 | spi->mode = save; | |
324 | else | |
325 | dev_dbg(&spi->dev, "%csb first\n", | |
326 | tmp ? 'l' : 'm'); | |
327 | } | |
328 | break; | |
329 | case SPI_IOC_WR_BITS_PER_WORD: | |
330 | retval = __get_user(tmp, (__u8 __user *)arg); | |
331 | if (retval == 0) { | |
332 | u8 save = spi->bits_per_word; | |
333 | ||
334 | spi->bits_per_word = tmp; | |
335 | retval = spi_setup(spi); | |
336 | if (retval < 0) | |
337 | spi->bits_per_word = save; | |
338 | else | |
339 | dev_dbg(&spi->dev, "%d bits per word\n", tmp); | |
340 | } | |
341 | break; | |
342 | case SPI_IOC_WR_MAX_SPEED_HZ: | |
343 | retval = __get_user(tmp, (__u32 __user *)arg); | |
344 | if (retval == 0) { | |
345 | u32 save = spi->max_speed_hz; | |
346 | ||
347 | spi->max_speed_hz = tmp; | |
348 | retval = spi_setup(spi); | |
349 | if (retval < 0) | |
350 | spi->max_speed_hz = save; | |
351 | else | |
352 | dev_dbg(&spi->dev, "%d Hz (max)\n", tmp); | |
353 | } | |
354 | break; | |
355 | ||
356 | default: | |
357 | /* segmented and/or full-duplex I/O request */ | |
358 | if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0)) | |
359 | || _IOC_DIR(cmd) != _IOC_WRITE) | |
360 | return -ENOTTY; | |
361 | ||
362 | tmp = _IOC_SIZE(cmd); | |
363 | if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) { | |
364 | retval = -EINVAL; | |
365 | break; | |
366 | } | |
367 | n_ioc = tmp / sizeof(struct spi_ioc_transfer); | |
368 | if (n_ioc == 0) | |
369 | break; | |
370 | ||
371 | /* copy into scratch area */ | |
372 | ioc = kmalloc(tmp, GFP_KERNEL); | |
373 | if (!ioc) { | |
374 | retval = -ENOMEM; | |
375 | break; | |
376 | } | |
377 | if (__copy_from_user(ioc, (void __user *)arg, tmp)) { | |
9bea3f29 | 378 | kfree(ioc); |
814a8d50 AP |
379 | retval = -EFAULT; |
380 | break; | |
381 | } | |
382 | ||
383 | /* translate to spi_message, execute */ | |
384 | retval = spidev_message(spidev, ioc, n_ioc); | |
385 | kfree(ioc); | |
386 | break; | |
387 | } | |
388 | return retval; | |
389 | } | |
390 | ||
391 | static int spidev_open(struct inode *inode, struct file *filp) | |
392 | { | |
393 | struct spidev_data *spidev; | |
394 | int status = -ENXIO; | |
395 | ||
396 | mutex_lock(&device_list_lock); | |
397 | ||
398 | list_for_each_entry(spidev, &device_list, device_entry) { | |
399 | if (spidev->dev.devt == inode->i_rdev) { | |
400 | status = 0; | |
401 | break; | |
402 | } | |
403 | } | |
404 | if (status == 0) { | |
405 | if (!spidev->buffer) { | |
406 | spidev->buffer = kmalloc(bufsiz, GFP_KERNEL); | |
407 | if (!spidev->buffer) { | |
408 | dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); | |
409 | status = -ENOMEM; | |
410 | } | |
411 | } | |
412 | if (status == 0) { | |
413 | spidev->users++; | |
414 | filp->private_data = spidev; | |
415 | nonseekable_open(inode, filp); | |
416 | } | |
417 | } else | |
418 | pr_debug("spidev: nothing for minor %d\n", iminor(inode)); | |
419 | ||
420 | mutex_unlock(&device_list_lock); | |
421 | return status; | |
422 | } | |
423 | ||
424 | static int spidev_release(struct inode *inode, struct file *filp) | |
425 | { | |
426 | struct spidev_data *spidev; | |
427 | int status = 0; | |
428 | ||
429 | mutex_lock(&device_list_lock); | |
430 | spidev = filp->private_data; | |
431 | filp->private_data = NULL; | |
432 | spidev->users--; | |
433 | if (!spidev->users) { | |
434 | kfree(spidev->buffer); | |
435 | spidev->buffer = NULL; | |
436 | } | |
437 | mutex_unlock(&device_list_lock); | |
438 | ||
439 | return status; | |
440 | } | |
441 | ||
442 | static struct file_operations spidev_fops = { | |
443 | .owner = THIS_MODULE, | |
444 | /* REVISIT switch to aio primitives, so that userspace | |
445 | * gets more complete API coverage. It'll simplify things | |
446 | * too, except for the locking. | |
447 | */ | |
448 | .write = spidev_write, | |
449 | .read = spidev_read, | |
450 | .ioctl = spidev_ioctl, | |
451 | .open = spidev_open, | |
452 | .release = spidev_release, | |
453 | }; | |
454 | ||
455 | /*-------------------------------------------------------------------------*/ | |
456 | ||
457 | /* The main reason to have this class is to make mdev/udev create the | |
458 | * /dev/spidevB.C character device nodes exposing our userspace API. | |
459 | * It also simplifies memory management. | |
460 | */ | |
461 | ||
462 | static void spidev_classdev_release(struct device *dev) | |
463 | { | |
464 | struct spidev_data *spidev; | |
465 | ||
466 | spidev = container_of(dev, struct spidev_data, dev); | |
467 | kfree(spidev); | |
468 | } | |
469 | ||
470 | static struct class spidev_class = { | |
471 | .name = "spidev", | |
472 | .owner = THIS_MODULE, | |
473 | .dev_release = spidev_classdev_release, | |
474 | }; | |
475 | ||
476 | /*-------------------------------------------------------------------------*/ | |
477 | ||
478 | static int spidev_probe(struct spi_device *spi) | |
479 | { | |
480 | struct spidev_data *spidev; | |
481 | int status; | |
482 | unsigned long minor; | |
483 | ||
484 | /* Allocate driver data */ | |
485 | spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); | |
486 | if (!spidev) | |
487 | return -ENOMEM; | |
488 | ||
489 | /* Initialize the driver data */ | |
490 | spidev->spi = spi; | |
491 | mutex_init(&spidev->buf_lock); | |
492 | ||
493 | INIT_LIST_HEAD(&spidev->device_entry); | |
494 | ||
495 | /* If we can allocate a minor number, hook up this device. | |
496 | * Reusing minors is fine so long as udev or mdev is working. | |
497 | */ | |
498 | mutex_lock(&device_list_lock); | |
0a4dd778 | 499 | minor = find_first_zero_bit(minors, N_SPI_MINORS); |
814a8d50 AP |
500 | if (minor < N_SPI_MINORS) { |
501 | spidev->dev.parent = &spi->dev; | |
502 | spidev->dev.class = &spidev_class; | |
503 | spidev->dev.devt = MKDEV(SPIDEV_MAJOR, minor); | |
504 | snprintf(spidev->dev.bus_id, sizeof spidev->dev.bus_id, | |
505 | "spidev%d.%d", | |
506 | spi->master->bus_num, spi->chip_select); | |
507 | status = device_register(&spidev->dev); | |
508 | } else { | |
509 | dev_dbg(&spi->dev, "no minor number available!\n"); | |
510 | status = -ENODEV; | |
511 | } | |
512 | if (status == 0) { | |
513 | set_bit(minor, minors); | |
514 | dev_set_drvdata(&spi->dev, spidev); | |
515 | list_add(&spidev->device_entry, &device_list); | |
516 | } | |
517 | mutex_unlock(&device_list_lock); | |
518 | ||
519 | if (status != 0) | |
520 | kfree(spidev); | |
521 | ||
522 | return status; | |
523 | } | |
524 | ||
525 | static int spidev_remove(struct spi_device *spi) | |
526 | { | |
527 | struct spidev_data *spidev = dev_get_drvdata(&spi->dev); | |
528 | ||
529 | mutex_lock(&device_list_lock); | |
530 | ||
531 | list_del(&spidev->device_entry); | |
532 | dev_set_drvdata(&spi->dev, NULL); | |
533 | clear_bit(MINOR(spidev->dev.devt), minors); | |
534 | device_unregister(&spidev->dev); | |
535 | ||
536 | mutex_unlock(&device_list_lock); | |
537 | ||
538 | return 0; | |
539 | } | |
540 | ||
541 | static struct spi_driver spidev_spi = { | |
542 | .driver = { | |
543 | .name = "spidev", | |
544 | .owner = THIS_MODULE, | |
545 | }, | |
546 | .probe = spidev_probe, | |
547 | .remove = __devexit_p(spidev_remove), | |
548 | ||
549 | /* NOTE: suspend/resume methods are not necessary here. | |
550 | * We don't do anything except pass the requests to/from | |
551 | * the underlying controller. The refrigerator handles | |
552 | * most issues; the controller driver handles the rest. | |
553 | */ | |
554 | }; | |
555 | ||
556 | /*-------------------------------------------------------------------------*/ | |
557 | ||
558 | static int __init spidev_init(void) | |
559 | { | |
560 | int status; | |
561 | ||
562 | /* Claim our 256 reserved device numbers. Then register a class | |
563 | * that will key udev/mdev to add/remove /dev nodes. Last, register | |
564 | * the driver which manages those device numbers. | |
565 | */ | |
566 | BUILD_BUG_ON(N_SPI_MINORS > 256); | |
567 | status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops); | |
568 | if (status < 0) | |
569 | return status; | |
570 | ||
571 | status = class_register(&spidev_class); | |
572 | if (status < 0) { | |
573 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); | |
574 | return status; | |
575 | } | |
576 | ||
577 | status = spi_register_driver(&spidev_spi); | |
578 | if (status < 0) { | |
579 | class_unregister(&spidev_class); | |
580 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); | |
581 | } | |
582 | return status; | |
583 | } | |
584 | module_init(spidev_init); | |
585 | ||
586 | static void __exit spidev_exit(void) | |
587 | { | |
588 | spi_unregister_driver(&spidev_spi); | |
589 | class_unregister(&spidev_class); | |
590 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name); | |
591 | } | |
592 | module_exit(spidev_exit); | |
593 | ||
594 | MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>"); | |
595 | MODULE_DESCRIPTION("User mode SPI device interface"); | |
596 | MODULE_LICENSE("GPL"); |