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10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/ioctl.h>
13#include <linux/fs.h>
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/list.h>
17#include <linux/errno.h>
18#include <linux/mutex.h>
19#include <linux/slab.h>
20#include <linux/compat.h>
21#include <linux/of.h>
22#include <linux/of_device.h>
23#include <linux/acpi.h>
24
25#include <linux/spi/spi.h>
26#include <linux/spi/spidev.h>
27
28#include <linux/uaccess.h>
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44#define SPIDEV_MAJOR 153
45#define N_SPI_MINORS 32
46
47static DECLARE_BITMAP(minors, N_SPI_MINORS);
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62#define SPI_MODE_MASK (SPI_MODE_X_MASK | SPI_CS_HIGH \
63 | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
64 | SPI_NO_CS | SPI_READY | SPI_TX_DUAL \
65 | SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL \
66 | SPI_RX_QUAD | SPI_RX_OCTAL)
67
68struct spidev_data {
69 dev_t devt;
70 spinlock_t spi_lock;
71 struct spi_device *spi;
72 struct list_head device_entry;
73
74
75 struct mutex buf_lock;
76 unsigned users;
77 u8 *tx_buffer;
78 u8 *rx_buffer;
79 u32 speed_hz;
80};
81
82static LIST_HEAD(device_list);
83static DEFINE_MUTEX(device_list_lock);
84
85static unsigned bufsiz = 4096;
86module_param(bufsiz, uint, S_IRUGO);
87MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");
88
89
90
91static ssize_t
92spidev_sync(struct spidev_data *spidev, struct spi_message *message)
93{
94 int status;
95 struct spi_device *spi;
96
97 spin_lock_irq(&spidev->spi_lock);
98 spi = spidev->spi;
99 spin_unlock_irq(&spidev->spi_lock);
100
101 if (spi == NULL)
102 status = -ESHUTDOWN;
103 else
104 status = spi_sync(spi, message);
105
106 if (status == 0)
107 status = message->actual_length;
108
109 return status;
110}
111
112static inline ssize_t
113spidev_sync_write(struct spidev_data *spidev, size_t len)
114{
115 struct spi_transfer t = {
116 .tx_buf = spidev->tx_buffer,
117 .len = len,
118 .speed_hz = spidev->speed_hz,
119 };
120 struct spi_message m;
121
122 spi_message_init(&m);
123 spi_message_add_tail(&t, &m);
124 return spidev_sync(spidev, &m);
125}
126
127static inline ssize_t
128spidev_sync_read(struct spidev_data *spidev, size_t len)
129{
130 struct spi_transfer t = {
131 .rx_buf = spidev->rx_buffer,
132 .len = len,
133 .speed_hz = spidev->speed_hz,
134 };
135 struct spi_message m;
136
137 spi_message_init(&m);
138 spi_message_add_tail(&t, &m);
139 return spidev_sync(spidev, &m);
140}
141
142
143
144
145static ssize_t
146spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
147{
148 struct spidev_data *spidev;
149 ssize_t status;
150
151
152 if (count > bufsiz)
153 return -EMSGSIZE;
154
155 spidev = filp->private_data;
156
157 mutex_lock(&spidev->buf_lock);
158 status = spidev_sync_read(spidev, count);
159 if (status > 0) {
160 unsigned long missing;
161
162 missing = copy_to_user(buf, spidev->rx_buffer, status);
163 if (missing == status)
164 status = -EFAULT;
165 else
166 status = status - missing;
167 }
168 mutex_unlock(&spidev->buf_lock);
169
170 return status;
171}
172
173
174static ssize_t
175spidev_write(struct file *filp, const char __user *buf,
176 size_t count, loff_t *f_pos)
177{
178 struct spidev_data *spidev;
179 ssize_t status;
180 unsigned long missing;
181
182
183 if (count > bufsiz)
184 return -EMSGSIZE;
185
186 spidev = filp->private_data;
187
188 mutex_lock(&spidev->buf_lock);
189 missing = copy_from_user(spidev->tx_buffer, buf, count);
190 if (missing == 0)
191 status = spidev_sync_write(spidev, count);
192 else
193 status = -EFAULT;
194 mutex_unlock(&spidev->buf_lock);
195
196 return status;
197}
198
199static int spidev_message(struct spidev_data *spidev,
200 struct spi_ioc_transfer *u_xfers, unsigned n_xfers)
201{
202 struct spi_message msg;
203 struct spi_transfer *k_xfers;
204 struct spi_transfer *k_tmp;
205 struct spi_ioc_transfer *u_tmp;
206 unsigned n, total, tx_total, rx_total;
207 u8 *tx_buf, *rx_buf;
208 int status = -EFAULT;
209
210 spi_message_init(&msg);
211 k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL);
212 if (k_xfers == NULL)
213 return -ENOMEM;
214
215
216
217
218
219 tx_buf = spidev->tx_buffer;
220 rx_buf = spidev->rx_buffer;
221 total = 0;
222 tx_total = 0;
223 rx_total = 0;
224 for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
225 n;
226 n--, k_tmp++, u_tmp++) {
227
228
229
230 unsigned int len_aligned = ALIGN(u_tmp->len, ARCH_KMALLOC_MINALIGN);
231
232 k_tmp->len = u_tmp->len;
233
234 total += k_tmp->len;
235
236
237
238
239
240 if (total > INT_MAX || k_tmp->len > INT_MAX) {
241 status = -EMSGSIZE;
242 goto done;
243 }
244
245 if (u_tmp->rx_buf) {
246
247 rx_total += len_aligned;
248 if (rx_total > bufsiz) {
249 status = -EMSGSIZE;
250 goto done;
251 }
252 k_tmp->rx_buf = rx_buf;
253 rx_buf += len_aligned;
254 }
255 if (u_tmp->tx_buf) {
256
257 tx_total += len_aligned;
258 if (tx_total > bufsiz) {
259 status = -EMSGSIZE;
260 goto done;
261 }
262 k_tmp->tx_buf = tx_buf;
263 if (copy_from_user(tx_buf, (const u8 __user *)
264 (uintptr_t) u_tmp->tx_buf,
265 u_tmp->len))
266 goto done;
267 tx_buf += len_aligned;
268 }
269
270 k_tmp->cs_change = !!u_tmp->cs_change;
271 k_tmp->tx_nbits = u_tmp->tx_nbits;
272 k_tmp->rx_nbits = u_tmp->rx_nbits;
273 k_tmp->bits_per_word = u_tmp->bits_per_word;
274 k_tmp->delay.value = u_tmp->delay_usecs;
275 k_tmp->delay.unit = SPI_DELAY_UNIT_USECS;
276 k_tmp->speed_hz = u_tmp->speed_hz;
277 k_tmp->word_delay.value = u_tmp->word_delay_usecs;
278 k_tmp->word_delay.unit = SPI_DELAY_UNIT_USECS;
279 if (!k_tmp->speed_hz)
280 k_tmp->speed_hz = spidev->speed_hz;
281#ifdef VERBOSE
282 dev_dbg(&spidev->spi->dev,
283 " xfer len %u %s%s%s%dbits %u usec %u usec %uHz\n",
284 k_tmp->len,
285 k_tmp->rx_buf ? "rx " : "",
286 k_tmp->tx_buf ? "tx " : "",
287 k_tmp->cs_change ? "cs " : "",
288 k_tmp->bits_per_word ? : spidev->spi->bits_per_word,
289 k_tmp->delay.value,
290 k_tmp->word_delay.value,
291 k_tmp->speed_hz ? : spidev->spi->max_speed_hz);
292#endif
293 spi_message_add_tail(k_tmp, &msg);
294 }
295
296 status = spidev_sync(spidev, &msg);
297 if (status < 0)
298 goto done;
299
300
301 for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
302 n;
303 n--, k_tmp++, u_tmp++) {
304 if (u_tmp->rx_buf) {
305 if (copy_to_user((u8 __user *)
306 (uintptr_t) u_tmp->rx_buf, k_tmp->rx_buf,
307 u_tmp->len)) {
308 status = -EFAULT;
309 goto done;
310 }
311 }
312 }
313 status = total;
314
315done:
316 kfree(k_xfers);
317 return status;
318}
319
320static struct spi_ioc_transfer *
321spidev_get_ioc_message(unsigned int cmd, struct spi_ioc_transfer __user *u_ioc,
322 unsigned *n_ioc)
323{
324 u32 tmp;
325
326
327 if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC
328 || _IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0))
329 || _IOC_DIR(cmd) != _IOC_WRITE)
330 return ERR_PTR(-ENOTTY);
331
332 tmp = _IOC_SIZE(cmd);
333 if ((tmp % sizeof(struct spi_ioc_transfer)) != 0)
334 return ERR_PTR(-EINVAL);
335 *n_ioc = tmp / sizeof(struct spi_ioc_transfer);
336 if (*n_ioc == 0)
337 return NULL;
338
339
340 return memdup_user(u_ioc, tmp);
341}
342
343static long
344spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
345{
346 int retval = 0;
347 struct spidev_data *spidev;
348 struct spi_device *spi;
349 u32 tmp;
350 unsigned n_ioc;
351 struct spi_ioc_transfer *ioc;
352
353
354 if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
355 return -ENOTTY;
356
357
358
359
360 spidev = filp->private_data;
361 spin_lock_irq(&spidev->spi_lock);
362 spi = spi_dev_get(spidev->spi);
363 spin_unlock_irq(&spidev->spi_lock);
364
365 if (spi == NULL)
366 return -ESHUTDOWN;
367
368
369
370
371
372
373
374 mutex_lock(&spidev->buf_lock);
375
376 switch (cmd) {
377
378 case SPI_IOC_RD_MODE:
379 retval = put_user(spi->mode & SPI_MODE_MASK,
380 (__u8 __user *)arg);
381 break;
382 case SPI_IOC_RD_MODE32:
383 retval = put_user(spi->mode & SPI_MODE_MASK,
384 (__u32 __user *)arg);
385 break;
386 case SPI_IOC_RD_LSB_FIRST:
387 retval = put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0,
388 (__u8 __user *)arg);
389 break;
390 case SPI_IOC_RD_BITS_PER_WORD:
391 retval = put_user(spi->bits_per_word, (__u8 __user *)arg);
392 break;
393 case SPI_IOC_RD_MAX_SPEED_HZ:
394 retval = put_user(spidev->speed_hz, (__u32 __user *)arg);
395 break;
396
397
398 case SPI_IOC_WR_MODE:
399 case SPI_IOC_WR_MODE32:
400 if (cmd == SPI_IOC_WR_MODE)
401 retval = get_user(tmp, (u8 __user *)arg);
402 else
403 retval = get_user(tmp, (u32 __user *)arg);
404 if (retval == 0) {
405 struct spi_controller *ctlr = spi->controller;
406 u32 save = spi->mode;
407
408 if (tmp & ~SPI_MODE_MASK) {
409 retval = -EINVAL;
410 break;
411 }
412
413 if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods &&
414 ctlr->cs_gpiods[spi->chip_select])
415 tmp |= SPI_CS_HIGH;
416
417 tmp |= spi->mode & ~SPI_MODE_MASK;
418 spi->mode = (u16)tmp;
419 retval = spi_setup(spi);
420 if (retval < 0)
421 spi->mode = save;
422 else
423 dev_dbg(&spi->dev, "spi mode %x\n", tmp);
424 }
425 break;
426 case SPI_IOC_WR_LSB_FIRST:
427 retval = get_user(tmp, (__u8 __user *)arg);
428 if (retval == 0) {
429 u32 save = spi->mode;
430
431 if (tmp)
432 spi->mode |= SPI_LSB_FIRST;
433 else
434 spi->mode &= ~SPI_LSB_FIRST;
435 retval = spi_setup(spi);
436 if (retval < 0)
437 spi->mode = save;
438 else
439 dev_dbg(&spi->dev, "%csb first\n",
440 tmp ? 'l' : 'm');
441 }
442 break;
443 case SPI_IOC_WR_BITS_PER_WORD:
444 retval = get_user(tmp, (__u8 __user *)arg);
445 if (retval == 0) {
446 u8 save = spi->bits_per_word;
447
448 spi->bits_per_word = tmp;
449 retval = spi_setup(spi);
450 if (retval < 0)
451 spi->bits_per_word = save;
452 else
453 dev_dbg(&spi->dev, "%d bits per word\n", tmp);
454 }
455 break;
456 case SPI_IOC_WR_MAX_SPEED_HZ:
457 retval = get_user(tmp, (__u32 __user *)arg);
458 if (retval == 0) {
459 u32 save = spi->max_speed_hz;
460
461 spi->max_speed_hz = tmp;
462 retval = spi_setup(spi);
463 if (retval == 0) {
464 spidev->speed_hz = tmp;
465 dev_dbg(&spi->dev, "%d Hz (max)\n",
466 spidev->speed_hz);
467 }
468 spi->max_speed_hz = save;
469 }
470 break;
471
472 default:
473
474
475 ioc = spidev_get_ioc_message(cmd,
476 (struct spi_ioc_transfer __user *)arg, &n_ioc);
477 if (IS_ERR(ioc)) {
478 retval = PTR_ERR(ioc);
479 break;
480 }
481 if (!ioc)
482 break;
483
484
485 retval = spidev_message(spidev, ioc, n_ioc);
486 kfree(ioc);
487 break;
488 }
489
490 mutex_unlock(&spidev->buf_lock);
491 spi_dev_put(spi);
492 return retval;
493}
494
495#ifdef CONFIG_COMPAT
496static long
497spidev_compat_ioc_message(struct file *filp, unsigned int cmd,
498 unsigned long arg)
499{
500 struct spi_ioc_transfer __user *u_ioc;
501 int retval = 0;
502 struct spidev_data *spidev;
503 struct spi_device *spi;
504 unsigned n_ioc, n;
505 struct spi_ioc_transfer *ioc;
506
507 u_ioc = (struct spi_ioc_transfer __user *) compat_ptr(arg);
508
509
510
511
512 spidev = filp->private_data;
513 spin_lock_irq(&spidev->spi_lock);
514 spi = spi_dev_get(spidev->spi);
515 spin_unlock_irq(&spidev->spi_lock);
516
517 if (spi == NULL)
518 return -ESHUTDOWN;
519
520
521 mutex_lock(&spidev->buf_lock);
522
523
524 ioc = spidev_get_ioc_message(cmd, u_ioc, &n_ioc);
525 if (IS_ERR(ioc)) {
526 retval = PTR_ERR(ioc);
527 goto done;
528 }
529 if (!ioc)
530 goto done;
531
532
533 for (n = 0; n < n_ioc; n++) {
534 ioc[n].rx_buf = (uintptr_t) compat_ptr(ioc[n].rx_buf);
535 ioc[n].tx_buf = (uintptr_t) compat_ptr(ioc[n].tx_buf);
536 }
537
538
539 retval = spidev_message(spidev, ioc, n_ioc);
540 kfree(ioc);
541
542done:
543 mutex_unlock(&spidev->buf_lock);
544 spi_dev_put(spi);
545 return retval;
546}
547
548static long
549spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
550{
551 if (_IOC_TYPE(cmd) == SPI_IOC_MAGIC
552 && _IOC_NR(cmd) == _IOC_NR(SPI_IOC_MESSAGE(0))
553 && _IOC_DIR(cmd) == _IOC_WRITE)
554 return spidev_compat_ioc_message(filp, cmd, arg);
555
556 return spidev_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
557}
558#else
559#define spidev_compat_ioctl NULL
560#endif
561
562static int spidev_open(struct inode *inode, struct file *filp)
563{
564 struct spidev_data *spidev;
565 int status = -ENXIO;
566
567 mutex_lock(&device_list_lock);
568
569 list_for_each_entry(spidev, &device_list, device_entry) {
570 if (spidev->devt == inode->i_rdev) {
571 status = 0;
572 break;
573 }
574 }
575
576 if (status) {
577 pr_debug("spidev: nothing for minor %d\n", iminor(inode));
578 goto err_find_dev;
579 }
580
581 if (!spidev->tx_buffer) {
582 spidev->tx_buffer = kmalloc(bufsiz, GFP_KERNEL);
583 if (!spidev->tx_buffer) {
584 dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
585 status = -ENOMEM;
586 goto err_find_dev;
587 }
588 }
589
590 if (!spidev->rx_buffer) {
591 spidev->rx_buffer = kmalloc(bufsiz, GFP_KERNEL);
592 if (!spidev->rx_buffer) {
593 dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
594 status = -ENOMEM;
595 goto err_alloc_rx_buf;
596 }
597 }
598
599 spidev->users++;
600 filp->private_data = spidev;
601 stream_open(inode, filp);
602
603 mutex_unlock(&device_list_lock);
604 return 0;
605
606err_alloc_rx_buf:
607 kfree(spidev->tx_buffer);
608 spidev->tx_buffer = NULL;
609err_find_dev:
610 mutex_unlock(&device_list_lock);
611 return status;
612}
613
614static int spidev_release(struct inode *inode, struct file *filp)
615{
616 struct spidev_data *spidev;
617 int dofree;
618
619 mutex_lock(&device_list_lock);
620 spidev = filp->private_data;
621 filp->private_data = NULL;
622
623 spin_lock_irq(&spidev->spi_lock);
624
625 dofree = (spidev->spi == NULL);
626 spin_unlock_irq(&spidev->spi_lock);
627
628
629 spidev->users--;
630 if (!spidev->users) {
631
632 kfree(spidev->tx_buffer);
633 spidev->tx_buffer = NULL;
634
635 kfree(spidev->rx_buffer);
636 spidev->rx_buffer = NULL;
637
638 if (dofree)
639 kfree(spidev);
640 else
641 spidev->speed_hz = spidev->spi->max_speed_hz;
642 }
643#ifdef CONFIG_SPI_SLAVE
644 if (!dofree)
645 spi_slave_abort(spidev->spi);
646#endif
647 mutex_unlock(&device_list_lock);
648
649 return 0;
650}
651
652static const struct file_operations spidev_fops = {
653 .owner = THIS_MODULE,
654
655
656
657
658 .write = spidev_write,
659 .read = spidev_read,
660 .unlocked_ioctl = spidev_ioctl,
661 .compat_ioctl = spidev_compat_ioctl,
662 .open = spidev_open,
663 .release = spidev_release,
664 .llseek = no_llseek,
665};
666
667
668
669
670
671
672
673
674static struct class *spidev_class;
675
676static const struct spi_device_id spidev_spi_ids[] = {
677 { .name = "dh2228fv" },
678 { .name = "ltc2488" },
679 { .name = "sx1301" },
680 { .name = "bk4" },
681 { .name = "dhcom-board" },
682 { .name = "m53cpld" },
683 { .name = "spi-petra" },
684 { .name = "spi-authenta" },
685 {},
686};
687MODULE_DEVICE_TABLE(spi, spidev_spi_ids);
688
689#ifdef CONFIG_OF
690static const struct of_device_id spidev_dt_ids[] = {
691 { .compatible = "rohm,dh2228fv" },
692 { .compatible = "lineartechnology,ltc2488" },
693 { .compatible = "semtech,sx1301" },
694 { .compatible = "lwn,bk4" },
695 { .compatible = "dh,dhcom-board" },
696 { .compatible = "menlo,m53cpld" },
697 { .compatible = "cisco,spi-petra" },
698 { .compatible = "micron,spi-authenta" },
699 {},
700};
701MODULE_DEVICE_TABLE(of, spidev_dt_ids);
702#endif
703
704#ifdef CONFIG_ACPI
705
706
707#define SPIDEV_ACPI_DUMMY 1
708
709static const struct acpi_device_id spidev_acpi_ids[] = {
710
711
712
713
714
715
716 { "SPT0001", SPIDEV_ACPI_DUMMY },
717 { "SPT0002", SPIDEV_ACPI_DUMMY },
718 { "SPT0003", SPIDEV_ACPI_DUMMY },
719 {},
720};
721MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids);
722
723static void spidev_probe_acpi(struct spi_device *spi)
724{
725 const struct acpi_device_id *id;
726
727 if (!has_acpi_companion(&spi->dev))
728 return;
729
730 id = acpi_match_device(spidev_acpi_ids, &spi->dev);
731 if (WARN_ON(!id))
732 return;
733
734 if (id->driver_data == SPIDEV_ACPI_DUMMY)
735 dev_warn(&spi->dev, "do not use this driver in production systems!\n");
736}
737#else
738static inline void spidev_probe_acpi(struct spi_device *spi) {}
739#endif
740
741
742
743static int spidev_probe(struct spi_device *spi)
744{
745 struct spidev_data *spidev;
746 int status;
747 unsigned long minor;
748
749
750
751
752
753
754 WARN(spi->dev.of_node &&
755 of_device_is_compatible(spi->dev.of_node, "spidev"),
756 "%pOF: buggy DT: spidev listed directly in DT\n", spi->dev.of_node);
757
758 spidev_probe_acpi(spi);
759
760
761 spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
762 if (!spidev)
763 return -ENOMEM;
764
765
766 spidev->spi = spi;
767 spin_lock_init(&spidev->spi_lock);
768 mutex_init(&spidev->buf_lock);
769
770 INIT_LIST_HEAD(&spidev->device_entry);
771
772
773
774
775 mutex_lock(&device_list_lock);
776 minor = find_first_zero_bit(minors, N_SPI_MINORS);
777 if (minor < N_SPI_MINORS) {
778 struct device *dev;
779
780 spidev->devt = MKDEV(SPIDEV_MAJOR, minor);
781 dev = device_create(spidev_class, &spi->dev, spidev->devt,
782 spidev, "spidev%d.%d",
783 spi->master->bus_num, spi->chip_select);
784 status = PTR_ERR_OR_ZERO(dev);
785 } else {
786 dev_dbg(&spi->dev, "no minor number available!\n");
787 status = -ENODEV;
788 }
789 if (status == 0) {
790 set_bit(minor, minors);
791 list_add(&spidev->device_entry, &device_list);
792 }
793 mutex_unlock(&device_list_lock);
794
795 spidev->speed_hz = spi->max_speed_hz;
796
797 if (status == 0)
798 spi_set_drvdata(spi, spidev);
799 else
800 kfree(spidev);
801
802 return status;
803}
804
805static int spidev_remove(struct spi_device *spi)
806{
807 struct spidev_data *spidev = spi_get_drvdata(spi);
808
809
810 mutex_lock(&device_list_lock);
811
812 spin_lock_irq(&spidev->spi_lock);
813 spidev->spi = NULL;
814 spin_unlock_irq(&spidev->spi_lock);
815
816 list_del(&spidev->device_entry);
817 device_destroy(spidev_class, spidev->devt);
818 clear_bit(MINOR(spidev->devt), minors);
819 if (spidev->users == 0)
820 kfree(spidev);
821 mutex_unlock(&device_list_lock);
822
823 return 0;
824}
825
826static struct spi_driver spidev_spi_driver = {
827 .driver = {
828 .name = "spidev",
829 .of_match_table = of_match_ptr(spidev_dt_ids),
830 .acpi_match_table = ACPI_PTR(spidev_acpi_ids),
831 },
832 .probe = spidev_probe,
833 .remove = spidev_remove,
834 .id_table = spidev_spi_ids,
835
836
837
838
839
840
841};
842
843
844
845static int __init spidev_init(void)
846{
847 int status;
848
849
850
851
852
853 BUILD_BUG_ON(N_SPI_MINORS > 256);
854 status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops);
855 if (status < 0)
856 return status;
857
858 spidev_class = class_create(THIS_MODULE, "spidev");
859 if (IS_ERR(spidev_class)) {
860 unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name);
861 return PTR_ERR(spidev_class);
862 }
863
864 status = spi_register_driver(&spidev_spi_driver);
865 if (status < 0) {
866 class_destroy(spidev_class);
867 unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name);
868 }
869 return status;
870}
871module_init(spidev_init);
872
873static void __exit spidev_exit(void)
874{
875 spi_unregister_driver(&spidev_spi_driver);
876 class_destroy(spidev_class);
877 unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name);
878}
879module_exit(spidev_exit);
880
881MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
882MODULE_DESCRIPTION("User mode SPI device interface");
883MODULE_LICENSE("GPL");
884MODULE_ALIAS("spi:spidev");
885