1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Simple synchronous userspace interface to SPI devices
5 * Copyright (C) 2006 SWAPP
6 * Andrea Paterniani <a.paterniani@swapp-eng.it>
7 * Copyright (C) 2007 David Brownell (simplification, cleanup)
10 #include <linux/init.h>
11 #include <linux/ioctl.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/list.h>
16 #include <linux/errno.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/property.h>
21 #include <linux/slab.h>
22 #include <linux/compat.h>
24 #include <linux/spi/spi.h>
25 #include <linux/spi/spidev.h>
27 #include <linux/uaccess.h>
31 * This supports access to SPI devices using normal userspace I/O calls.
32 * Note that while traditional UNIX/POSIX I/O semantics are half duplex,
33 * and often mask message boundaries, full SPI support requires full duplex
34 * transfers. There are several kinds of internal message boundaries to
35 * handle chipselect management and other protocol options.
37 * SPI has a character major number assigned. We allocate minor numbers
38 * dynamically using a bitmask. You must use hotplug tools, such as udev
39 * (or mdev with busybox) to create and destroy the /dev/spidevB.C device
40 * nodes, since there is no fixed association of minor numbers with any
41 * particular SPI bus or device.
43 #define SPIDEV_MAJOR 153 /* assigned */
44 #define N_SPI_MINORS 32 /* ... up to 256 */
46 static DECLARE_BITMAP(minors
, N_SPI_MINORS
);
48 static_assert(N_SPI_MINORS
> 0 && N_SPI_MINORS
<= 256);
50 /* Bit masks for spi_device.mode management. Note that incorrect
51 * settings for some settings can cause *lots* of trouble for other
52 * devices on a shared bus:
54 * - CS_HIGH ... this device will be active when it shouldn't be
55 * - 3WIRE ... when active, it won't behave as it should
56 * - NO_CS ... there will be no explicit message boundaries; this
57 * is completely incompatible with the shared bus model
58 * - READY ... transfers may proceed when they shouldn't.
60 * REVISIT should changing those flags be privileged?
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 | SPI_RX_CPHA_FLIP | SPI_3WIRE_HIZ \
72 struct mutex spi_lock
;
73 struct spi_device
*spi
;
74 struct list_head device_entry
;
76 /* TX/RX buffers are NULL unless this device is open (users > 0) */
77 struct mutex buf_lock
;
84 static LIST_HEAD(device_list
);
85 static DEFINE_MUTEX(device_list_lock
);
87 static unsigned bufsiz
= 4096;
88 module_param(bufsiz
, uint
, S_IRUGO
);
89 MODULE_PARM_DESC(bufsiz
, "data bytes in biggest supported SPI message");
91 /*-------------------------------------------------------------------------*/
94 spidev_sync_unlocked(struct spi_device
*spi
, struct spi_message
*message
)
98 status
= spi_sync(spi
, message
);
100 status
= message
->actual_length
;
106 spidev_sync(struct spidev_data
*spidev
, struct spi_message
*message
)
109 struct spi_device
*spi
;
111 mutex_lock(&spidev
->spi_lock
);
117 status
= spidev_sync_unlocked(spi
, message
);
119 mutex_unlock(&spidev
->spi_lock
);
123 static inline ssize_t
124 spidev_sync_write(struct spidev_data
*spidev
, size_t len
)
126 struct spi_transfer t
= {
127 .tx_buf
= spidev
->tx_buffer
,
129 .speed_hz
= spidev
->speed_hz
,
131 struct spi_message m
;
133 spi_message_init(&m
);
134 spi_message_add_tail(&t
, &m
);
135 return spidev_sync(spidev
, &m
);
138 static inline ssize_t
139 spidev_sync_read(struct spidev_data
*spidev
, size_t len
)
141 struct spi_transfer t
= {
142 .rx_buf
= spidev
->rx_buffer
,
144 .speed_hz
= spidev
->speed_hz
,
146 struct spi_message m
;
148 spi_message_init(&m
);
149 spi_message_add_tail(&t
, &m
);
150 return spidev_sync(spidev
, &m
);
153 /*-------------------------------------------------------------------------*/
155 /* Read-only message with current device setup */
157 spidev_read(struct file
*filp
, char __user
*buf
, size_t count
, loff_t
*f_pos
)
159 struct spidev_data
*spidev
;
162 /* chipselect only toggles at start or end of operation */
166 spidev
= filp
->private_data
;
168 mutex_lock(&spidev
->buf_lock
);
169 status
= spidev_sync_read(spidev
, count
);
171 unsigned long missing
;
173 missing
= copy_to_user(buf
, spidev
->rx_buffer
, status
);
174 if (missing
== status
)
177 status
= status
- missing
;
179 mutex_unlock(&spidev
->buf_lock
);
184 /* Write-only message with current device setup */
186 spidev_write(struct file
*filp
, const char __user
*buf
,
187 size_t count
, loff_t
*f_pos
)
189 struct spidev_data
*spidev
;
191 unsigned long missing
;
193 /* chipselect only toggles at start or end of operation */
197 spidev
= filp
->private_data
;
199 mutex_lock(&spidev
->buf_lock
);
200 missing
= copy_from_user(spidev
->tx_buffer
, buf
, count
);
202 status
= spidev_sync_write(spidev
, count
);
205 mutex_unlock(&spidev
->buf_lock
);
210 static int spidev_message(struct spidev_data
*spidev
,
211 struct spi_ioc_transfer
*u_xfers
, unsigned n_xfers
)
213 struct spi_message msg
;
214 struct spi_transfer
*k_xfers
;
215 struct spi_transfer
*k_tmp
;
216 struct spi_ioc_transfer
*u_tmp
;
217 unsigned n
, total
, tx_total
, rx_total
;
219 int status
= -EFAULT
;
221 spi_message_init(&msg
);
222 k_xfers
= kcalloc(n_xfers
, sizeof(*k_tmp
), GFP_KERNEL
);
226 /* Construct spi_message, copying any tx data to bounce buffer.
227 * We walk the array of user-provided transfers, using each one
228 * to initialize a kernel version of the same transfer.
230 tx_buf
= spidev
->tx_buffer
;
231 rx_buf
= spidev
->rx_buffer
;
235 for (n
= n_xfers
, k_tmp
= k_xfers
, u_tmp
= u_xfers
;
237 n
--, k_tmp
++, u_tmp
++) {
238 /* Ensure that also following allocations from rx_buf/tx_buf will meet
239 * DMA alignment requirements.
241 unsigned int len_aligned
= ALIGN(u_tmp
->len
, ARCH_DMA_MINALIGN
);
243 k_tmp
->len
= u_tmp
->len
;
246 /* Since the function returns the total length of transfers
247 * on success, restrict the total to positive int values to
248 * avoid the return value looking like an error. Also check
249 * each transfer length to avoid arithmetic overflow.
251 if (total
> INT_MAX
|| k_tmp
->len
> INT_MAX
) {
257 /* this transfer needs space in RX bounce buffer */
258 rx_total
+= len_aligned
;
259 if (rx_total
> bufsiz
) {
263 k_tmp
->rx_buf
= rx_buf
;
264 rx_buf
+= len_aligned
;
267 /* this transfer needs space in TX bounce buffer */
268 tx_total
+= len_aligned
;
269 if (tx_total
> bufsiz
) {
273 k_tmp
->tx_buf
= tx_buf
;
274 if (copy_from_user(tx_buf
, (const u8 __user
*)
275 (uintptr_t) u_tmp
->tx_buf
,
278 tx_buf
+= len_aligned
;
281 k_tmp
->cs_change
= !!u_tmp
->cs_change
;
282 k_tmp
->tx_nbits
= u_tmp
->tx_nbits
;
283 k_tmp
->rx_nbits
= u_tmp
->rx_nbits
;
284 k_tmp
->bits_per_word
= u_tmp
->bits_per_word
;
285 k_tmp
->delay
.value
= u_tmp
->delay_usecs
;
286 k_tmp
->delay
.unit
= SPI_DELAY_UNIT_USECS
;
287 k_tmp
->speed_hz
= u_tmp
->speed_hz
;
288 k_tmp
->word_delay
.value
= u_tmp
->word_delay_usecs
;
289 k_tmp
->word_delay
.unit
= SPI_DELAY_UNIT_USECS
;
290 if (!k_tmp
->speed_hz
)
291 k_tmp
->speed_hz
= spidev
->speed_hz
;
293 dev_dbg(&spidev
->spi
->dev
,
294 " xfer len %u %s%s%s%dbits %u usec %u usec %uHz\n",
296 k_tmp
->rx_buf
? "rx " : "",
297 k_tmp
->tx_buf
? "tx " : "",
298 k_tmp
->cs_change
? "cs " : "",
299 k_tmp
->bits_per_word
? : spidev
->spi
->bits_per_word
,
301 k_tmp
->word_delay
.value
,
302 k_tmp
->speed_hz
? : spidev
->spi
->max_speed_hz
);
304 spi_message_add_tail(k_tmp
, &msg
);
307 status
= spidev_sync_unlocked(spidev
->spi
, &msg
);
311 /* copy any rx data out of bounce buffer */
312 for (n
= n_xfers
, k_tmp
= k_xfers
, u_tmp
= u_xfers
;
314 n
--, k_tmp
++, u_tmp
++) {
316 if (copy_to_user((u8 __user
*)
317 (uintptr_t) u_tmp
->rx_buf
, k_tmp
->rx_buf
,
331 static struct spi_ioc_transfer
*
332 spidev_get_ioc_message(unsigned int cmd
, struct spi_ioc_transfer __user
*u_ioc
,
337 /* Check type, command number and direction */
338 if (_IOC_TYPE(cmd
) != SPI_IOC_MAGIC
339 || _IOC_NR(cmd
) != _IOC_NR(SPI_IOC_MESSAGE(0))
340 || _IOC_DIR(cmd
) != _IOC_WRITE
)
341 return ERR_PTR(-ENOTTY
);
343 tmp
= _IOC_SIZE(cmd
);
344 if ((tmp
% sizeof(struct spi_ioc_transfer
)) != 0)
345 return ERR_PTR(-EINVAL
);
346 *n_ioc
= tmp
/ sizeof(struct spi_ioc_transfer
);
350 /* copy into scratch area */
351 return memdup_user(u_ioc
, tmp
);
355 spidev_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
358 struct spidev_data
*spidev
;
359 struct spi_device
*spi
;
360 struct spi_controller
*ctlr
;
363 struct spi_ioc_transfer
*ioc
;
365 /* Check type and command number */
366 if (_IOC_TYPE(cmd
) != SPI_IOC_MAGIC
)
369 /* guard against device removal before, or while,
370 * we issue this ioctl.
372 spidev
= filp
->private_data
;
373 mutex_lock(&spidev
->spi_lock
);
374 spi
= spi_dev_get(spidev
->spi
);
376 mutex_unlock(&spidev
->spi_lock
);
380 ctlr
= spi
->controller
;
382 /* use the buffer lock here for triple duty:
383 * - prevent I/O (from us) so calling spi_setup() is safe;
384 * - prevent concurrent SPI_IOC_WR_* from morphing
385 * data fields while SPI_IOC_RD_* reads them;
386 * - SPI_IOC_MESSAGE needs the buffer locked "normally".
388 mutex_lock(&spidev
->buf_lock
);
392 case SPI_IOC_RD_MODE
:
393 case SPI_IOC_RD_MODE32
:
394 tmp
= spi
->mode
& SPI_MODE_MASK
;
396 if (ctlr
->use_gpio_descriptors
&& spi_get_csgpiod(spi
, 0))
399 if (cmd
== SPI_IOC_RD_MODE
)
400 retval
= put_user(tmp
, (__u8 __user
*)arg
);
402 retval
= put_user(tmp
, (__u32 __user
*)arg
);
404 case SPI_IOC_RD_LSB_FIRST
:
405 retval
= put_user((spi
->mode
& SPI_LSB_FIRST
) ? 1 : 0,
408 case SPI_IOC_RD_BITS_PER_WORD
:
409 retval
= put_user(spi
->bits_per_word
, (__u8 __user
*)arg
);
411 case SPI_IOC_RD_MAX_SPEED_HZ
:
412 retval
= put_user(spidev
->speed_hz
, (__u32 __user
*)arg
);
416 case SPI_IOC_WR_MODE
:
417 case SPI_IOC_WR_MODE32
:
418 if (cmd
== SPI_IOC_WR_MODE
)
419 retval
= get_user(tmp
, (u8 __user
*)arg
);
421 retval
= get_user(tmp
, (u32 __user
*)arg
);
423 u32 save
= spi
->mode
;
425 if (tmp
& ~SPI_MODE_MASK
) {
430 if (ctlr
->use_gpio_descriptors
&& spi_get_csgpiod(spi
, 0))
433 tmp
|= spi
->mode
& ~SPI_MODE_MASK
;
434 spi
->mode
= tmp
& SPI_MODE_USER_MASK
;
435 retval
= spi_setup(spi
);
439 dev_dbg(&spi
->dev
, "spi mode %x\n", tmp
);
442 case SPI_IOC_WR_LSB_FIRST
:
443 retval
= get_user(tmp
, (__u8 __user
*)arg
);
445 u32 save
= spi
->mode
;
448 spi
->mode
|= SPI_LSB_FIRST
;
450 spi
->mode
&= ~SPI_LSB_FIRST
;
451 retval
= spi_setup(spi
);
455 dev_dbg(&spi
->dev
, "%csb first\n",
459 case SPI_IOC_WR_BITS_PER_WORD
:
460 retval
= get_user(tmp
, (__u8 __user
*)arg
);
462 u8 save
= spi
->bits_per_word
;
464 spi
->bits_per_word
= tmp
;
465 retval
= spi_setup(spi
);
467 spi
->bits_per_word
= save
;
469 dev_dbg(&spi
->dev
, "%d bits per word\n", tmp
);
472 case SPI_IOC_WR_MAX_SPEED_HZ
: {
475 retval
= get_user(tmp
, (__u32 __user
*)arg
);
483 save
= spi
->max_speed_hz
;
485 spi
->max_speed_hz
= tmp
;
486 retval
= spi_setup(spi
);
488 spidev
->speed_hz
= tmp
;
489 dev_dbg(&spi
->dev
, "%d Hz (max)\n", spidev
->speed_hz
);
492 spi
->max_speed_hz
= save
;
496 /* segmented and/or full-duplex I/O request */
497 /* Check message and copy into scratch area */
498 ioc
= spidev_get_ioc_message(cmd
,
499 (struct spi_ioc_transfer __user
*)arg
, &n_ioc
);
501 retval
= PTR_ERR(ioc
);
505 break; /* n_ioc is also 0 */
507 /* translate to spi_message, execute */
508 retval
= spidev_message(spidev
, ioc
, n_ioc
);
513 mutex_unlock(&spidev
->buf_lock
);
515 mutex_unlock(&spidev
->spi_lock
);
521 spidev_compat_ioc_message(struct file
*filp
, unsigned int cmd
,
524 struct spi_ioc_transfer __user
*u_ioc
;
526 struct spidev_data
*spidev
;
527 struct spi_device
*spi
;
529 struct spi_ioc_transfer
*ioc
;
531 u_ioc
= (struct spi_ioc_transfer __user
*) compat_ptr(arg
);
533 /* guard against device removal before, or while,
534 * we issue this ioctl.
536 spidev
= filp
->private_data
;
537 mutex_lock(&spidev
->spi_lock
);
538 spi
= spi_dev_get(spidev
->spi
);
540 mutex_unlock(&spidev
->spi_lock
);
544 /* SPI_IOC_MESSAGE needs the buffer locked "normally" */
545 mutex_lock(&spidev
->buf_lock
);
547 /* Check message and copy into scratch area */
548 ioc
= spidev_get_ioc_message(cmd
, u_ioc
, &n_ioc
);
550 retval
= PTR_ERR(ioc
);
554 goto done
; /* n_ioc is also 0 */
556 /* Convert buffer pointers */
557 for (n
= 0; n
< n_ioc
; n
++) {
558 ioc
[n
].rx_buf
= (uintptr_t) compat_ptr(ioc
[n
].rx_buf
);
559 ioc
[n
].tx_buf
= (uintptr_t) compat_ptr(ioc
[n
].tx_buf
);
562 /* translate to spi_message, execute */
563 retval
= spidev_message(spidev
, ioc
, n_ioc
);
567 mutex_unlock(&spidev
->buf_lock
);
569 mutex_unlock(&spidev
->spi_lock
);
574 spidev_compat_ioctl(struct file
*filp
, unsigned int cmd
, unsigned long arg
)
576 if (_IOC_TYPE(cmd
) == SPI_IOC_MAGIC
577 && _IOC_NR(cmd
) == _IOC_NR(SPI_IOC_MESSAGE(0))
578 && _IOC_DIR(cmd
) == _IOC_WRITE
)
579 return spidev_compat_ioc_message(filp
, cmd
, arg
);
581 return spidev_ioctl(filp
, cmd
, (unsigned long)compat_ptr(arg
));
584 #define spidev_compat_ioctl NULL
585 #endif /* CONFIG_COMPAT */
587 static int spidev_open(struct inode
*inode
, struct file
*filp
)
589 struct spidev_data
*spidev
= NULL
, *iter
;
592 mutex_lock(&device_list_lock
);
594 list_for_each_entry(iter
, &device_list
, device_entry
) {
595 if (iter
->devt
== inode
->i_rdev
) {
603 pr_debug("spidev: nothing for minor %d\n", iminor(inode
));
607 if (!spidev
->tx_buffer
) {
608 spidev
->tx_buffer
= kmalloc(bufsiz
, GFP_KERNEL
);
609 if (!spidev
->tx_buffer
) {
615 if (!spidev
->rx_buffer
) {
616 spidev
->rx_buffer
= kmalloc(bufsiz
, GFP_KERNEL
);
617 if (!spidev
->rx_buffer
) {
619 goto err_alloc_rx_buf
;
624 filp
->private_data
= spidev
;
625 stream_open(inode
, filp
);
627 mutex_unlock(&device_list_lock
);
631 kfree(spidev
->tx_buffer
);
632 spidev
->tx_buffer
= NULL
;
634 mutex_unlock(&device_list_lock
);
638 static int spidev_release(struct inode
*inode
, struct file
*filp
)
640 struct spidev_data
*spidev
;
643 mutex_lock(&device_list_lock
);
644 spidev
= filp
->private_data
;
645 filp
->private_data
= NULL
;
647 mutex_lock(&spidev
->spi_lock
);
648 /* ... after we unbound from the underlying device? */
649 dofree
= (spidev
->spi
== NULL
);
650 mutex_unlock(&spidev
->spi_lock
);
654 if (!spidev
->users
) {
656 kfree(spidev
->tx_buffer
);
657 spidev
->tx_buffer
= NULL
;
659 kfree(spidev
->rx_buffer
);
660 spidev
->rx_buffer
= NULL
;
665 spidev
->speed_hz
= spidev
->spi
->max_speed_hz
;
667 #ifdef CONFIG_SPI_SLAVE
669 spi_target_abort(spidev
->spi
);
671 mutex_unlock(&device_list_lock
);
676 static const struct file_operations spidev_fops
= {
677 .owner
= THIS_MODULE
,
678 /* REVISIT switch to aio primitives, so that userspace
679 * gets more complete API coverage. It'll simplify things
680 * too, except for the locking.
682 .write
= spidev_write
,
684 .unlocked_ioctl
= spidev_ioctl
,
685 .compat_ioctl
= spidev_compat_ioctl
,
687 .release
= spidev_release
,
690 /*-------------------------------------------------------------------------*/
692 /* The main reason to have this class is to make mdev/udev create the
693 * /dev/spidevB.C character device nodes exposing our userspace API.
694 * It also simplifies memory management.
697 static const struct class spidev_class
= {
701 static const struct spi_device_id spidev_spi_ids
[] = {
702 { .name
= "bh2228fv" },
703 { .name
= "dh2228fv" },
704 { .name
= "jg10309-01" },
705 { .name
= "ltc2488" },
706 { .name
= "sx1301" },
708 { .name
= "dhcom-board" },
709 { .name
= "m53cpld" },
710 { .name
= "spi-petra" },
711 { .name
= "spi-authenta" },
712 { .name
= "em3581" },
713 { .name
= "si3210" },
716 MODULE_DEVICE_TABLE(spi
, spidev_spi_ids
);
719 * spidev should never be referenced in DT without a specific compatible string,
720 * it is a Linux implementation thing rather than a description of the hardware.
722 static int spidev_of_check(struct device
*dev
)
724 if (device_property_match_string(dev
, "compatible", "spidev") < 0)
727 dev_err(dev
, "spidev listed directly in DT is not supported\n");
731 static const struct of_device_id spidev_dt_ids
[] = {
732 { .compatible
= "cisco,spi-petra", .data
= &spidev_of_check
},
733 { .compatible
= "dh,dhcom-board", .data
= &spidev_of_check
},
734 { .compatible
= "elgin,jg10309-01", .data
= &spidev_of_check
},
735 { .compatible
= "lineartechnology,ltc2488", .data
= &spidev_of_check
},
736 { .compatible
= "lwn,bk4", .data
= &spidev_of_check
},
737 { .compatible
= "menlo,m53cpld", .data
= &spidev_of_check
},
738 { .compatible
= "micron,spi-authenta", .data
= &spidev_of_check
},
739 { .compatible
= "rohm,bh2228fv", .data
= &spidev_of_check
},
740 { .compatible
= "rohm,dh2228fv", .data
= &spidev_of_check
},
741 { .compatible
= "semtech,sx1301", .data
= &spidev_of_check
},
742 { .compatible
= "silabs,em3581", .data
= &spidev_of_check
},
743 { .compatible
= "silabs,si3210", .data
= &spidev_of_check
},
746 MODULE_DEVICE_TABLE(of
, spidev_dt_ids
);
748 /* Dummy SPI devices not to be used in production systems */
749 static int spidev_acpi_check(struct device
*dev
)
751 dev_warn(dev
, "do not use this driver in production systems!\n");
755 static const struct acpi_device_id spidev_acpi_ids
[] = {
757 * The ACPI SPT000* devices are only meant for development and
758 * testing. Systems used in production should have a proper ACPI
759 * description of the connected peripheral and they should also use
760 * a proper driver instead of poking directly to the SPI bus.
762 { "SPT0001", (kernel_ulong_t
)&spidev_acpi_check
},
763 { "SPT0002", (kernel_ulong_t
)&spidev_acpi_check
},
764 { "SPT0003", (kernel_ulong_t
)&spidev_acpi_check
},
767 MODULE_DEVICE_TABLE(acpi
, spidev_acpi_ids
);
769 /*-------------------------------------------------------------------------*/
771 static int spidev_probe(struct spi_device
*spi
)
773 int (*match
)(struct device
*dev
);
774 struct spidev_data
*spidev
;
778 match
= device_get_match_data(&spi
->dev
);
780 status
= match(&spi
->dev
);
785 /* Allocate driver data */
786 spidev
= kzalloc(sizeof(*spidev
), GFP_KERNEL
);
790 /* Initialize the driver data */
792 mutex_init(&spidev
->spi_lock
);
793 mutex_init(&spidev
->buf_lock
);
795 INIT_LIST_HEAD(&spidev
->device_entry
);
797 /* If we can allocate a minor number, hook up this device.
798 * Reusing minors is fine so long as udev or mdev is working.
800 mutex_lock(&device_list_lock
);
801 minor
= find_first_zero_bit(minors
, N_SPI_MINORS
);
802 if (minor
< N_SPI_MINORS
) {
805 spidev
->devt
= MKDEV(SPIDEV_MAJOR
, minor
);
806 dev
= device_create(&spidev_class
, &spi
->dev
, spidev
->devt
,
807 spidev
, "spidev%d.%d",
808 spi
->controller
->bus_num
, spi_get_chipselect(spi
, 0));
809 status
= PTR_ERR_OR_ZERO(dev
);
811 dev_dbg(&spi
->dev
, "no minor number available!\n");
815 set_bit(minor
, minors
);
816 list_add(&spidev
->device_entry
, &device_list
);
818 mutex_unlock(&device_list_lock
);
820 spidev
->speed_hz
= spi
->max_speed_hz
;
823 spi_set_drvdata(spi
, spidev
);
830 static void spidev_remove(struct spi_device
*spi
)
832 struct spidev_data
*spidev
= spi_get_drvdata(spi
);
834 /* prevent new opens */
835 mutex_lock(&device_list_lock
);
836 /* make sure ops on existing fds can abort cleanly */
837 mutex_lock(&spidev
->spi_lock
);
839 mutex_unlock(&spidev
->spi_lock
);
841 list_del(&spidev
->device_entry
);
842 device_destroy(&spidev_class
, spidev
->devt
);
843 clear_bit(MINOR(spidev
->devt
), minors
);
844 if (spidev
->users
== 0)
846 mutex_unlock(&device_list_lock
);
849 static struct spi_driver spidev_spi_driver
= {
852 .of_match_table
= spidev_dt_ids
,
853 .acpi_match_table
= spidev_acpi_ids
,
855 .probe
= spidev_probe
,
856 .remove
= spidev_remove
,
857 .id_table
= spidev_spi_ids
,
859 /* NOTE: suspend/resume methods are not necessary here.
860 * We don't do anything except pass the requests to/from
861 * the underlying controller. The refrigerator handles
862 * most issues; the controller driver handles the rest.
866 /*-------------------------------------------------------------------------*/
868 static int __init
spidev_init(void)
872 /* Claim our 256 reserved device numbers. Then register a class
873 * that will key udev/mdev to add/remove /dev nodes. Last, register
874 * the driver which manages those device numbers.
876 status
= register_chrdev(SPIDEV_MAJOR
, "spi", &spidev_fops
);
880 status
= class_register(&spidev_class
);
882 unregister_chrdev(SPIDEV_MAJOR
, spidev_spi_driver
.driver
.name
);
886 status
= spi_register_driver(&spidev_spi_driver
);
888 class_unregister(&spidev_class
);
889 unregister_chrdev(SPIDEV_MAJOR
, spidev_spi_driver
.driver
.name
);
893 module_init(spidev_init
);
895 static void __exit
spidev_exit(void)
897 spi_unregister_driver(&spidev_spi_driver
);
898 class_unregister(&spidev_class
);
899 unregister_chrdev(SPIDEV_MAJOR
, spidev_spi_driver
.driver
.name
);
901 module_exit(spidev_exit
);
903 MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
904 MODULE_DESCRIPTION("User mode SPI device interface");
905 MODULE_LICENSE("GPL");
906 MODULE_ALIAS("spi:spidev");