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Commit | Line | Data |
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814a8d50 | 1 | /* |
ca632f55 | 2 | * Simple synchronous userspace interface to SPI devices |
814a8d50 AP |
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. | |
814a8d50 AP |
17 | */ |
18 | ||
19 | #include <linux/init.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/ioctl.h> | |
22 | #include <linux/fs.h> | |
23 | #include <linux/device.h> | |
b2c8dadd | 24 | #include <linux/err.h> |
814a8d50 AP |
25 | #include <linux/list.h> |
26 | #include <linux/errno.h> | |
27 | #include <linux/mutex.h> | |
28 | #include <linux/slab.h> | |
7d48ec36 | 29 | #include <linux/compat.h> |
880cfd43 MR |
30 | #include <linux/of.h> |
31 | #include <linux/of_device.h> | |
cf9f4327 | 32 | #include <linux/acpi.h> |
814a8d50 AP |
33 | |
34 | #include <linux/spi/spi.h> | |
35 | #include <linux/spi/spidev.h> | |
36 | ||
95c63cfb | 37 | #include <linux/uaccess.h> |
814a8d50 AP |
38 | |
39 | ||
40 | /* | |
b595076a | 41 | * This supports access to SPI devices using normal userspace I/O calls. |
814a8d50 AP |
42 | * Note that while traditional UNIX/POSIX I/O semantics are half duplex, |
43 | * and often mask message boundaries, full SPI support requires full duplex | |
137f1188 | 44 | * transfers. There are several kinds of internal message boundaries to |
814a8d50 AP |
45 | * handle chipselect management and other protocol options. |
46 | * | |
47 | * SPI has a character major number assigned. We allocate minor numbers | |
48 | * dynamically using a bitmask. You must use hotplug tools, such as udev | |
49 | * (or mdev with busybox) to create and destroy the /dev/spidevB.C device | |
50 | * nodes, since there is no fixed association of minor numbers with any | |
51 | * particular SPI bus or device. | |
52 | */ | |
53 | #define SPIDEV_MAJOR 153 /* assigned */ | |
54 | #define N_SPI_MINORS 32 /* ... up to 256 */ | |
55 | ||
8ae1c924 | 56 | static DECLARE_BITMAP(minors, N_SPI_MINORS); |
814a8d50 AP |
57 | |
58 | ||
6f166e38 | 59 | /* Bit masks for spi_device.mode management. Note that incorrect |
b55f627f DB |
60 | * settings for some settings can cause *lots* of trouble for other |
61 | * devices on a shared bus: | |
6f166e38 | 62 | * |
b55f627f DB |
63 | * - CS_HIGH ... this device will be active when it shouldn't be |
64 | * - 3WIRE ... when active, it won't behave as it should | |
65 | * - NO_CS ... there will be no explicit message boundaries; this | |
66 | * is completely incompatible with the shared bus model | |
67 | * - READY ... transfers may proceed when they shouldn't. | |
68 | * | |
69 | * REVISIT should changing those flags be privileged? | |
6f166e38 AV |
70 | */ |
71 | #define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \ | |
b55f627f | 72 | | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \ |
dc64d39b GU |
73 | | SPI_NO_CS | SPI_READY | SPI_TX_DUAL \ |
74 | | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD) | |
814a8d50 AP |
75 | |
76 | struct spidev_data { | |
b2c8dadd | 77 | dev_t devt; |
25d5cb4b | 78 | spinlock_t spi_lock; |
814a8d50 AP |
79 | struct spi_device *spi; |
80 | struct list_head device_entry; | |
81 | ||
865f6d19 | 82 | /* TX/RX buffers are NULL unless this device is open (users > 0) */ |
814a8d50 AP |
83 | struct mutex buf_lock; |
84 | unsigned users; | |
865f6d19 RJ |
85 | u8 *tx_buffer; |
86 | u8 *rx_buffer; | |
91690516 | 87 | u32 speed_hz; |
814a8d50 AP |
88 | }; |
89 | ||
90 | static LIST_HEAD(device_list); | |
91 | static DEFINE_MUTEX(device_list_lock); | |
92 | ||
93 | static unsigned bufsiz = 4096; | |
94 | module_param(bufsiz, uint, S_IRUGO); | |
95 | MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); | |
96 | ||
97 | /*-------------------------------------------------------------------------*/ | |
98 | ||
25d5cb4b DB |
99 | static ssize_t |
100 | spidev_sync(struct spidev_data *spidev, struct spi_message *message) | |
101 | { | |
25d5cb4b | 102 | int status; |
98d6f479 | 103 | struct spi_device *spi; |
25d5cb4b DB |
104 | |
105 | spin_lock_irq(&spidev->spi_lock); | |
98d6f479 MS |
106 | spi = spidev->spi; |
107 | spin_unlock_irq(&spidev->spi_lock); | |
108 | ||
109 | if (spi == NULL) | |
25d5cb4b DB |
110 | status = -ESHUTDOWN; |
111 | else | |
98d6f479 MS |
112 | status = spi_sync(spi, message); |
113 | ||
114 | if (status == 0) | |
115 | status = message->actual_length; | |
25d5cb4b | 116 | |
25d5cb4b DB |
117 | return status; |
118 | } | |
119 | ||
120 | static inline ssize_t | |
121 | spidev_sync_write(struct spidev_data *spidev, size_t len) | |
122 | { | |
123 | struct spi_transfer t = { | |
865f6d19 | 124 | .tx_buf = spidev->tx_buffer, |
25d5cb4b | 125 | .len = len, |
91690516 | 126 | .speed_hz = spidev->speed_hz, |
25d5cb4b DB |
127 | }; |
128 | struct spi_message m; | |
129 | ||
130 | spi_message_init(&m); | |
131 | spi_message_add_tail(&t, &m); | |
132 | return spidev_sync(spidev, &m); | |
133 | } | |
134 | ||
135 | static inline ssize_t | |
136 | spidev_sync_read(struct spidev_data *spidev, size_t len) | |
137 | { | |
138 | struct spi_transfer t = { | |
865f6d19 | 139 | .rx_buf = spidev->rx_buffer, |
25d5cb4b | 140 | .len = len, |
91690516 | 141 | .speed_hz = spidev->speed_hz, |
25d5cb4b DB |
142 | }; |
143 | struct spi_message m; | |
144 | ||
145 | spi_message_init(&m); | |
146 | spi_message_add_tail(&t, &m); | |
147 | return spidev_sync(spidev, &m); | |
148 | } | |
149 | ||
150 | /*-------------------------------------------------------------------------*/ | |
151 | ||
814a8d50 AP |
152 | /* Read-only message with current device setup */ |
153 | static ssize_t | |
154 | spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) | |
155 | { | |
156 | struct spidev_data *spidev; | |
814a8d50 AP |
157 | ssize_t status = 0; |
158 | ||
159 | /* chipselect only toggles at start or end of operation */ | |
160 | if (count > bufsiz) | |
161 | return -EMSGSIZE; | |
162 | ||
163 | spidev = filp->private_data; | |
814a8d50 AP |
164 | |
165 | mutex_lock(&spidev->buf_lock); | |
25d5cb4b | 166 | status = spidev_sync_read(spidev, count); |
4b1295b0 | 167 | if (status > 0) { |
814a8d50 AP |
168 | unsigned long missing; |
169 | ||
865f6d19 | 170 | missing = copy_to_user(buf, spidev->rx_buffer, status); |
4b1295b0 | 171 | if (missing == status) |
814a8d50 AP |
172 | status = -EFAULT; |
173 | else | |
4b1295b0 | 174 | status = status - missing; |
814a8d50 AP |
175 | } |
176 | mutex_unlock(&spidev->buf_lock); | |
177 | ||
178 | return status; | |
179 | } | |
180 | ||
181 | /* Write-only message with current device setup */ | |
182 | static ssize_t | |
183 | spidev_write(struct file *filp, const char __user *buf, | |
184 | size_t count, loff_t *f_pos) | |
185 | { | |
186 | struct spidev_data *spidev; | |
814a8d50 AP |
187 | ssize_t status = 0; |
188 | unsigned long missing; | |
189 | ||
190 | /* chipselect only toggles at start or end of operation */ | |
191 | if (count > bufsiz) | |
192 | return -EMSGSIZE; | |
193 | ||
194 | spidev = filp->private_data; | |
814a8d50 AP |
195 | |
196 | mutex_lock(&spidev->buf_lock); | |
865f6d19 | 197 | missing = copy_from_user(spidev->tx_buffer, buf, count); |
95c63cfb | 198 | if (missing == 0) |
25d5cb4b | 199 | status = spidev_sync_write(spidev, count); |
95c63cfb | 200 | else |
814a8d50 AP |
201 | status = -EFAULT; |
202 | mutex_unlock(&spidev->buf_lock); | |
203 | ||
204 | return status; | |
205 | } | |
206 | ||
207 | static int spidev_message(struct spidev_data *spidev, | |
208 | struct spi_ioc_transfer *u_xfers, unsigned n_xfers) | |
209 | { | |
210 | struct spi_message msg; | |
211 | struct spi_transfer *k_xfers; | |
212 | struct spi_transfer *k_tmp; | |
213 | struct spi_ioc_transfer *u_tmp; | |
9a12bff7 | 214 | unsigned n, total, tx_total, rx_total; |
865f6d19 | 215 | u8 *tx_buf, *rx_buf; |
814a8d50 AP |
216 | int status = -EFAULT; |
217 | ||
218 | spi_message_init(&msg); | |
219 | k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL); | |
220 | if (k_xfers == NULL) | |
221 | return -ENOMEM; | |
222 | ||
223 | /* Construct spi_message, copying any tx data to bounce buffer. | |
224 | * We walk the array of user-provided transfers, using each one | |
225 | * to initialize a kernel version of the same transfer. | |
226 | */ | |
865f6d19 RJ |
227 | tx_buf = spidev->tx_buffer; |
228 | rx_buf = spidev->rx_buffer; | |
814a8d50 | 229 | total = 0; |
9a12bff7 IA |
230 | tx_total = 0; |
231 | rx_total = 0; | |
814a8d50 AP |
232 | for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; |
233 | n; | |
234 | n--, k_tmp++, u_tmp++) { | |
235 | k_tmp->len = u_tmp->len; | |
236 | ||
da90fa8f | 237 | total += k_tmp->len; |
9a12bff7 IA |
238 | /* Since the function returns the total length of transfers |
239 | * on success, restrict the total to positive int values to | |
f20fbaad IA |
240 | * avoid the return value looking like an error. Also check |
241 | * each transfer length to avoid arithmetic overflow. | |
9a12bff7 | 242 | */ |
f20fbaad | 243 | if (total > INT_MAX || k_tmp->len > INT_MAX) { |
da90fa8f DP |
244 | status = -EMSGSIZE; |
245 | goto done; | |
246 | } | |
247 | ||
814a8d50 | 248 | if (u_tmp->rx_buf) { |
9a12bff7 IA |
249 | /* this transfer needs space in RX bounce buffer */ |
250 | rx_total += k_tmp->len; | |
251 | if (rx_total > bufsiz) { | |
252 | status = -EMSGSIZE; | |
253 | goto done; | |
254 | } | |
865f6d19 | 255 | k_tmp->rx_buf = rx_buf; |
9a12bff7 | 256 | rx_buf += k_tmp->len; |
814a8d50 AP |
257 | } |
258 | if (u_tmp->tx_buf) { | |
9a12bff7 IA |
259 | /* this transfer needs space in TX bounce buffer */ |
260 | tx_total += k_tmp->len; | |
261 | if (tx_total > bufsiz) { | |
262 | status = -EMSGSIZE; | |
263 | goto done; | |
264 | } | |
865f6d19 RJ |
265 | k_tmp->tx_buf = tx_buf; |
266 | if (copy_from_user(tx_buf, (const u8 __user *) | |
142956af | 267 | (uintptr_t) u_tmp->tx_buf, |
814a8d50 AP |
268 | u_tmp->len)) |
269 | goto done; | |
9a12bff7 | 270 | tx_buf += k_tmp->len; |
814a8d50 | 271 | } |
814a8d50 AP |
272 | |
273 | k_tmp->cs_change = !!u_tmp->cs_change; | |
dc64d39b GU |
274 | k_tmp->tx_nbits = u_tmp->tx_nbits; |
275 | k_tmp->rx_nbits = u_tmp->rx_nbits; | |
814a8d50 AP |
276 | k_tmp->bits_per_word = u_tmp->bits_per_word; |
277 | k_tmp->delay_usecs = u_tmp->delay_usecs; | |
278 | k_tmp->speed_hz = u_tmp->speed_hz; | |
91690516 MB |
279 | if (!k_tmp->speed_hz) |
280 | k_tmp->speed_hz = spidev->speed_hz; | |
814a8d50 | 281 | #ifdef VERBOSE |
41df70d9 | 282 | dev_dbg(&spidev->spi->dev, |
f15c5841 | 283 | " xfer len %u %s%s%s%dbits %u usec %uHz\n", |
814a8d50 AP |
284 | u_tmp->len, |
285 | u_tmp->rx_buf ? "rx " : "", | |
286 | u_tmp->tx_buf ? "tx " : "", | |
287 | u_tmp->cs_change ? "cs " : "", | |
41df70d9 | 288 | u_tmp->bits_per_word ? : spidev->spi->bits_per_word, |
814a8d50 | 289 | u_tmp->delay_usecs, |
41df70d9 | 290 | u_tmp->speed_hz ? : spidev->spi->max_speed_hz); |
814a8d50 AP |
291 | #endif |
292 | spi_message_add_tail(k_tmp, &msg); | |
293 | } | |
294 | ||
25d5cb4b | 295 | status = spidev_sync(spidev, &msg); |
814a8d50 AP |
296 | if (status < 0) |
297 | goto done; | |
298 | ||
299 | /* copy any rx data out of bounce buffer */ | |
865f6d19 | 300 | rx_buf = spidev->rx_buffer; |
814a8d50 AP |
301 | for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { |
302 | if (u_tmp->rx_buf) { | |
251d5951 | 303 | if (copy_to_user((u8 __user *) |
865f6d19 | 304 | (uintptr_t) u_tmp->rx_buf, rx_buf, |
814a8d50 AP |
305 | u_tmp->len)) { |
306 | status = -EFAULT; | |
307 | goto done; | |
308 | } | |
9a12bff7 | 309 | rx_buf += u_tmp->len; |
814a8d50 | 310 | } |
814a8d50 AP |
311 | } |
312 | status = total; | |
313 | ||
314 | done: | |
814a8d50 AP |
315 | kfree(k_xfers); |
316 | return status; | |
317 | } | |
318 | ||
7782a1a9 IA |
319 | static struct spi_ioc_transfer * |
320 | spidev_get_ioc_message(unsigned int cmd, struct spi_ioc_transfer __user *u_ioc, | |
321 | unsigned *n_ioc) | |
322 | { | |
7782a1a9 IA |
323 | u32 tmp; |
324 | ||
325 | /* Check type, command number and direction */ | |
326 | if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC | |
327 | || _IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0)) | |
328 | || _IOC_DIR(cmd) != _IOC_WRITE) | |
329 | return ERR_PTR(-ENOTTY); | |
330 | ||
331 | tmp = _IOC_SIZE(cmd); | |
332 | if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) | |
333 | return ERR_PTR(-EINVAL); | |
334 | *n_ioc = tmp / sizeof(struct spi_ioc_transfer); | |
335 | if (*n_ioc == 0) | |
336 | return NULL; | |
337 | ||
338 | /* copy into scratch area */ | |
f7929436 | 339 | return memdup_user(u_ioc, tmp); |
7782a1a9 IA |
340 | } |
341 | ||
4ef754b7 AC |
342 | static long |
343 | spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
814a8d50 | 344 | { |
814a8d50 AP |
345 | int retval = 0; |
346 | struct spidev_data *spidev; | |
347 | struct spi_device *spi; | |
348 | u32 tmp; | |
349 | unsigned n_ioc; | |
350 | struct spi_ioc_transfer *ioc; | |
351 | ||
352 | /* Check type and command number */ | |
353 | if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC) | |
354 | return -ENOTTY; | |
355 | ||
25d5cb4b DB |
356 | /* guard against device removal before, or while, |
357 | * we issue this ioctl. | |
358 | */ | |
814a8d50 | 359 | spidev = filp->private_data; |
25d5cb4b DB |
360 | spin_lock_irq(&spidev->spi_lock); |
361 | spi = spi_dev_get(spidev->spi); | |
362 | spin_unlock_irq(&spidev->spi_lock); | |
363 | ||
364 | if (spi == NULL) | |
365 | return -ESHUTDOWN; | |
814a8d50 | 366 | |
4ef754b7 AC |
367 | /* use the buffer lock here for triple duty: |
368 | * - prevent I/O (from us) so calling spi_setup() is safe; | |
369 | * - prevent concurrent SPI_IOC_WR_* from morphing | |
370 | * data fields while SPI_IOC_RD_* reads them; | |
371 | * - SPI_IOC_MESSAGE needs the buffer locked "normally". | |
372 | */ | |
373 | mutex_lock(&spidev->buf_lock); | |
374 | ||
814a8d50 AP |
375 | switch (cmd) { |
376 | /* read requests */ | |
377 | case SPI_IOC_RD_MODE: | |
251d5951 | 378 | retval = put_user(spi->mode & SPI_MODE_MASK, |
814a8d50 AP |
379 | (__u8 __user *)arg); |
380 | break; | |
dc64d39b | 381 | case SPI_IOC_RD_MODE32: |
251d5951 | 382 | retval = put_user(spi->mode & SPI_MODE_MASK, |
dc64d39b GU |
383 | (__u32 __user *)arg); |
384 | break; | |
814a8d50 | 385 | case SPI_IOC_RD_LSB_FIRST: |
251d5951 | 386 | retval = put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0, |
814a8d50 AP |
387 | (__u8 __user *)arg); |
388 | break; | |
389 | case SPI_IOC_RD_BITS_PER_WORD: | |
251d5951 | 390 | retval = put_user(spi->bits_per_word, (__u8 __user *)arg); |
814a8d50 AP |
391 | break; |
392 | case SPI_IOC_RD_MAX_SPEED_HZ: | |
251d5951 | 393 | retval = put_user(spidev->speed_hz, (__u32 __user *)arg); |
814a8d50 AP |
394 | break; |
395 | ||
396 | /* write requests */ | |
397 | case SPI_IOC_WR_MODE: | |
dc64d39b GU |
398 | case SPI_IOC_WR_MODE32: |
399 | if (cmd == SPI_IOC_WR_MODE) | |
251d5951 | 400 | retval = get_user(tmp, (u8 __user *)arg); |
dc64d39b | 401 | else |
251d5951 | 402 | retval = get_user(tmp, (u32 __user *)arg); |
814a8d50 | 403 | if (retval == 0) { |
e6456186 | 404 | u32 save = spi->mode; |
814a8d50 AP |
405 | |
406 | if (tmp & ~SPI_MODE_MASK) { | |
407 | retval = -EINVAL; | |
408 | break; | |
409 | } | |
410 | ||
411 | tmp |= spi->mode & ~SPI_MODE_MASK; | |
dc64d39b | 412 | spi->mode = (u16)tmp; |
814a8d50 AP |
413 | retval = spi_setup(spi); |
414 | if (retval < 0) | |
415 | spi->mode = save; | |
416 | else | |
dc64d39b | 417 | dev_dbg(&spi->dev, "spi mode %x\n", tmp); |
814a8d50 AP |
418 | } |
419 | break; | |
420 | case SPI_IOC_WR_LSB_FIRST: | |
251d5951 | 421 | retval = get_user(tmp, (__u8 __user *)arg); |
814a8d50 | 422 | if (retval == 0) { |
e6456186 | 423 | u32 save = spi->mode; |
814a8d50 AP |
424 | |
425 | if (tmp) | |
426 | spi->mode |= SPI_LSB_FIRST; | |
427 | else | |
428 | spi->mode &= ~SPI_LSB_FIRST; | |
429 | retval = spi_setup(spi); | |
430 | if (retval < 0) | |
431 | spi->mode = save; | |
432 | else | |
433 | dev_dbg(&spi->dev, "%csb first\n", | |
434 | tmp ? 'l' : 'm'); | |
435 | } | |
436 | break; | |
437 | case SPI_IOC_WR_BITS_PER_WORD: | |
251d5951 | 438 | retval = get_user(tmp, (__u8 __user *)arg); |
814a8d50 AP |
439 | if (retval == 0) { |
440 | u8 save = spi->bits_per_word; | |
441 | ||
442 | spi->bits_per_word = tmp; | |
443 | retval = spi_setup(spi); | |
444 | if (retval < 0) | |
445 | spi->bits_per_word = save; | |
446 | else | |
447 | dev_dbg(&spi->dev, "%d bits per word\n", tmp); | |
448 | } | |
449 | break; | |
450 | case SPI_IOC_WR_MAX_SPEED_HZ: | |
251d5951 | 451 | retval = get_user(tmp, (__u32 __user *)arg); |
814a8d50 AP |
452 | if (retval == 0) { |
453 | u32 save = spi->max_speed_hz; | |
454 | ||
455 | spi->max_speed_hz = tmp; | |
456 | retval = spi_setup(spi); | |
91690516 MB |
457 | if (retval >= 0) |
458 | spidev->speed_hz = tmp; | |
814a8d50 AP |
459 | else |
460 | dev_dbg(&spi->dev, "%d Hz (max)\n", tmp); | |
91690516 | 461 | spi->max_speed_hz = save; |
814a8d50 AP |
462 | } |
463 | break; | |
464 | ||
465 | default: | |
466 | /* segmented and/or full-duplex I/O request */ | |
7782a1a9 IA |
467 | /* Check message and copy into scratch area */ |
468 | ioc = spidev_get_ioc_message(cmd, | |
469 | (struct spi_ioc_transfer __user *)arg, &n_ioc); | |
470 | if (IS_ERR(ioc)) { | |
471 | retval = PTR_ERR(ioc); | |
814a8d50 AP |
472 | break; |
473 | } | |
7782a1a9 IA |
474 | if (!ioc) |
475 | break; /* n_ioc is also 0 */ | |
814a8d50 AP |
476 | |
477 | /* translate to spi_message, execute */ | |
478 | retval = spidev_message(spidev, ioc, n_ioc); | |
479 | kfree(ioc); | |
480 | break; | |
481 | } | |
4ef754b7 AC |
482 | |
483 | mutex_unlock(&spidev->buf_lock); | |
25d5cb4b | 484 | spi_dev_put(spi); |
814a8d50 AP |
485 | return retval; |
486 | } | |
487 | ||
7d48ec36 | 488 | #ifdef CONFIG_COMPAT |
7782a1a9 IA |
489 | static long |
490 | spidev_compat_ioc_message(struct file *filp, unsigned int cmd, | |
491 | unsigned long arg) | |
492 | { | |
493 | struct spi_ioc_transfer __user *u_ioc; | |
494 | int retval = 0; | |
495 | struct spidev_data *spidev; | |
496 | struct spi_device *spi; | |
497 | unsigned n_ioc, n; | |
498 | struct spi_ioc_transfer *ioc; | |
499 | ||
500 | u_ioc = (struct spi_ioc_transfer __user *) compat_ptr(arg); | |
7782a1a9 IA |
501 | |
502 | /* guard against device removal before, or while, | |
503 | * we issue this ioctl. | |
504 | */ | |
505 | spidev = filp->private_data; | |
506 | spin_lock_irq(&spidev->spi_lock); | |
507 | spi = spi_dev_get(spidev->spi); | |
508 | spin_unlock_irq(&spidev->spi_lock); | |
509 | ||
510 | if (spi == NULL) | |
511 | return -ESHUTDOWN; | |
512 | ||
513 | /* SPI_IOC_MESSAGE needs the buffer locked "normally" */ | |
514 | mutex_lock(&spidev->buf_lock); | |
515 | ||
516 | /* Check message and copy into scratch area */ | |
517 | ioc = spidev_get_ioc_message(cmd, u_ioc, &n_ioc); | |
518 | if (IS_ERR(ioc)) { | |
519 | retval = PTR_ERR(ioc); | |
520 | goto done; | |
521 | } | |
522 | if (!ioc) | |
523 | goto done; /* n_ioc is also 0 */ | |
524 | ||
525 | /* Convert buffer pointers */ | |
526 | for (n = 0; n < n_ioc; n++) { | |
527 | ioc[n].rx_buf = (uintptr_t) compat_ptr(ioc[n].rx_buf); | |
528 | ioc[n].tx_buf = (uintptr_t) compat_ptr(ioc[n].tx_buf); | |
529 | } | |
530 | ||
531 | /* translate to spi_message, execute */ | |
532 | retval = spidev_message(spidev, ioc, n_ioc); | |
533 | kfree(ioc); | |
534 | ||
535 | done: | |
536 | mutex_unlock(&spidev->buf_lock); | |
537 | spi_dev_put(spi); | |
538 | return retval; | |
539 | } | |
540 | ||
7d48ec36 BW |
541 | static long |
542 | spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
543 | { | |
7782a1a9 IA |
544 | if (_IOC_TYPE(cmd) == SPI_IOC_MAGIC |
545 | && _IOC_NR(cmd) == _IOC_NR(SPI_IOC_MESSAGE(0)) | |
546 | && _IOC_DIR(cmd) == _IOC_WRITE) | |
547 | return spidev_compat_ioc_message(filp, cmd, arg); | |
548 | ||
7d48ec36 BW |
549 | return spidev_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); |
550 | } | |
551 | #else | |
552 | #define spidev_compat_ioctl NULL | |
553 | #endif /* CONFIG_COMPAT */ | |
554 | ||
814a8d50 AP |
555 | static int spidev_open(struct inode *inode, struct file *filp) |
556 | { | |
557 | struct spidev_data *spidev; | |
558 | int status = -ENXIO; | |
559 | ||
560 | mutex_lock(&device_list_lock); | |
561 | ||
562 | list_for_each_entry(spidev, &device_list, device_entry) { | |
b2c8dadd | 563 | if (spidev->devt == inode->i_rdev) { |
814a8d50 AP |
564 | status = 0; |
565 | break; | |
566 | } | |
567 | } | |
865f6d19 RJ |
568 | |
569 | if (status) { | |
570 | pr_debug("spidev: nothing for minor %d\n", iminor(inode)); | |
571 | goto err_find_dev; | |
572 | } | |
573 | ||
574 | if (!spidev->tx_buffer) { | |
575 | spidev->tx_buffer = kmalloc(bufsiz, GFP_KERNEL); | |
576 | if (!spidev->tx_buffer) { | |
89a63566 CIK |
577 | dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); |
578 | status = -ENOMEM; | |
865f6d19 | 579 | goto err_find_dev; |
814a8d50 | 580 | } |
89a63566 | 581 | } |
865f6d19 RJ |
582 | |
583 | if (!spidev->rx_buffer) { | |
584 | spidev->rx_buffer = kmalloc(bufsiz, GFP_KERNEL); | |
585 | if (!spidev->rx_buffer) { | |
586 | dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); | |
587 | status = -ENOMEM; | |
588 | goto err_alloc_rx_buf; | |
814a8d50 | 589 | } |
865f6d19 RJ |
590 | } |
591 | ||
592 | spidev->users++; | |
593 | filp->private_data = spidev; | |
594 | nonseekable_open(inode, filp); | |
814a8d50 | 595 | |
865f6d19 RJ |
596 | mutex_unlock(&device_list_lock); |
597 | return 0; | |
598 | ||
599 | err_alloc_rx_buf: | |
600 | kfree(spidev->tx_buffer); | |
601 | spidev->tx_buffer = NULL; | |
602 | err_find_dev: | |
814a8d50 AP |
603 | mutex_unlock(&device_list_lock); |
604 | return status; | |
605 | } | |
606 | ||
607 | static int spidev_release(struct inode *inode, struct file *filp) | |
608 | { | |
609 | struct spidev_data *spidev; | |
814a8d50 AP |
610 | |
611 | mutex_lock(&device_list_lock); | |
612 | spidev = filp->private_data; | |
613 | filp->private_data = NULL; | |
b2c8dadd DB |
614 | |
615 | /* last close? */ | |
814a8d50 AP |
616 | spidev->users--; |
617 | if (!spidev->users) { | |
b2c8dadd DB |
618 | int dofree; |
619 | ||
865f6d19 RJ |
620 | kfree(spidev->tx_buffer); |
621 | spidev->tx_buffer = NULL; | |
622 | ||
623 | kfree(spidev->rx_buffer); | |
624 | spidev->rx_buffer = NULL; | |
b2c8dadd | 625 | |
56ea1075 | 626 | spin_lock_irq(&spidev->spi_lock); |
dd85ebf6 SM |
627 | if (spidev->spi) |
628 | spidev->speed_hz = spidev->spi->max_speed_hz; | |
91690516 | 629 | |
b2c8dadd | 630 | /* ... after we unbound from the underlying device? */ |
b2c8dadd DB |
631 | dofree = (spidev->spi == NULL); |
632 | spin_unlock_irq(&spidev->spi_lock); | |
633 | ||
634 | if (dofree) | |
635 | kfree(spidev); | |
814a8d50 AP |
636 | } |
637 | mutex_unlock(&device_list_lock); | |
638 | ||
99472cc0 | 639 | return 0; |
814a8d50 AP |
640 | } |
641 | ||
828c0950 | 642 | static const struct file_operations spidev_fops = { |
814a8d50 AP |
643 | .owner = THIS_MODULE, |
644 | /* REVISIT switch to aio primitives, so that userspace | |
645 | * gets more complete API coverage. It'll simplify things | |
646 | * too, except for the locking. | |
647 | */ | |
648 | .write = spidev_write, | |
649 | .read = spidev_read, | |
4ef754b7 | 650 | .unlocked_ioctl = spidev_ioctl, |
7d48ec36 | 651 | .compat_ioctl = spidev_compat_ioctl, |
814a8d50 AP |
652 | .open = spidev_open, |
653 | .release = spidev_release, | |
6038f373 | 654 | .llseek = no_llseek, |
814a8d50 AP |
655 | }; |
656 | ||
657 | /*-------------------------------------------------------------------------*/ | |
658 | ||
659 | /* The main reason to have this class is to make mdev/udev create the | |
660 | * /dev/spidevB.C character device nodes exposing our userspace API. | |
661 | * It also simplifies memory management. | |
662 | */ | |
663 | ||
b2c8dadd | 664 | static struct class *spidev_class; |
814a8d50 | 665 | |
956b200a MB |
666 | #ifdef CONFIG_OF |
667 | static const struct of_device_id spidev_dt_ids[] = { | |
668 | { .compatible = "rohm,dh2228fv" }, | |
6fec919b | 669 | { .compatible = "lineartechnology,ltc2488" }, |
144235ea | 670 | { .compatible = "ge,achc" }, |
91b46346 | 671 | { .compatible = "semtech,sx1301" }, |
956b200a MB |
672 | {}, |
673 | }; | |
674 | MODULE_DEVICE_TABLE(of, spidev_dt_ids); | |
675 | #endif | |
676 | ||
cf9f4327 MW |
677 | #ifdef CONFIG_ACPI |
678 | ||
679 | /* Dummy SPI devices not to be used in production systems */ | |
680 | #define SPIDEV_ACPI_DUMMY 1 | |
681 | ||
682 | static const struct acpi_device_id spidev_acpi_ids[] = { | |
683 | /* | |
684 | * The ACPI SPT000* devices are only meant for development and | |
685 | * testing. Systems used in production should have a proper ACPI | |
686 | * description of the connected peripheral and they should also use | |
687 | * a proper driver instead of poking directly to the SPI bus. | |
688 | */ | |
689 | { "SPT0001", SPIDEV_ACPI_DUMMY }, | |
690 | { "SPT0002", SPIDEV_ACPI_DUMMY }, | |
691 | { "SPT0003", SPIDEV_ACPI_DUMMY }, | |
692 | {}, | |
693 | }; | |
694 | MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids); | |
695 | ||
696 | static void spidev_probe_acpi(struct spi_device *spi) | |
697 | { | |
698 | const struct acpi_device_id *id; | |
699 | ||
700 | if (!has_acpi_companion(&spi->dev)) | |
701 | return; | |
702 | ||
703 | id = acpi_match_device(spidev_acpi_ids, &spi->dev); | |
704 | if (WARN_ON(!id)) | |
705 | return; | |
706 | ||
707 | if (id->driver_data == SPIDEV_ACPI_DUMMY) | |
708 | dev_warn(&spi->dev, "do not use this driver in production systems!\n"); | |
709 | } | |
710 | #else | |
711 | static inline void spidev_probe_acpi(struct spi_device *spi) {} | |
712 | #endif | |
713 | ||
814a8d50 AP |
714 | /*-------------------------------------------------------------------------*/ |
715 | ||
fd4a319b | 716 | static int spidev_probe(struct spi_device *spi) |
814a8d50 AP |
717 | { |
718 | struct spidev_data *spidev; | |
719 | int status; | |
720 | unsigned long minor; | |
721 | ||
956b200a MB |
722 | /* |
723 | * spidev should never be referenced in DT without a specific | |
ffe22888 | 724 | * compatible string, it is a Linux implementation thing |
956b200a MB |
725 | * rather than a description of the hardware. |
726 | */ | |
727 | if (spi->dev.of_node && !of_match_device(spidev_dt_ids, &spi->dev)) { | |
728 | dev_err(&spi->dev, "buggy DT: spidev listed directly in DT\n"); | |
729 | WARN_ON(spi->dev.of_node && | |
730 | !of_match_device(spidev_dt_ids, &spi->dev)); | |
731 | } | |
732 | ||
cf9f4327 MW |
733 | spidev_probe_acpi(spi); |
734 | ||
814a8d50 AP |
735 | /* Allocate driver data */ |
736 | spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); | |
737 | if (!spidev) | |
738 | return -ENOMEM; | |
739 | ||
740 | /* Initialize the driver data */ | |
741 | spidev->spi = spi; | |
25d5cb4b | 742 | spin_lock_init(&spidev->spi_lock); |
814a8d50 AP |
743 | mutex_init(&spidev->buf_lock); |
744 | ||
745 | INIT_LIST_HEAD(&spidev->device_entry); | |
746 | ||
747 | /* If we can allocate a minor number, hook up this device. | |
748 | * Reusing minors is fine so long as udev or mdev is working. | |
749 | */ | |
750 | mutex_lock(&device_list_lock); | |
0a4dd778 | 751 | minor = find_first_zero_bit(minors, N_SPI_MINORS); |
814a8d50 | 752 | if (minor < N_SPI_MINORS) { |
b2c8dadd DB |
753 | struct device *dev; |
754 | ||
755 | spidev->devt = MKDEV(SPIDEV_MAJOR, minor); | |
a9b12619 GKH |
756 | dev = device_create(spidev_class, &spi->dev, spidev->devt, |
757 | spidev, "spidev%d.%d", | |
758 | spi->master->bus_num, spi->chip_select); | |
8c6ffba0 | 759 | status = PTR_ERR_OR_ZERO(dev); |
814a8d50 AP |
760 | } else { |
761 | dev_dbg(&spi->dev, "no minor number available!\n"); | |
762 | status = -ENODEV; | |
763 | } | |
764 | if (status == 0) { | |
765 | set_bit(minor, minors); | |
814a8d50 AP |
766 | list_add(&spidev->device_entry, &device_list); |
767 | } | |
768 | mutex_unlock(&device_list_lock); | |
769 | ||
91690516 MB |
770 | spidev->speed_hz = spi->max_speed_hz; |
771 | ||
aaacf4bb WO |
772 | if (status == 0) |
773 | spi_set_drvdata(spi, spidev); | |
774 | else | |
814a8d50 AP |
775 | kfree(spidev); |
776 | ||
777 | return status; | |
778 | } | |
779 | ||
fd4a319b | 780 | static int spidev_remove(struct spi_device *spi) |
814a8d50 | 781 | { |
b2c8dadd | 782 | struct spidev_data *spidev = spi_get_drvdata(spi); |
814a8d50 | 783 | |
25d5cb4b DB |
784 | /* make sure ops on existing fds can abort cleanly */ |
785 | spin_lock_irq(&spidev->spi_lock); | |
786 | spidev->spi = NULL; | |
787 | spin_unlock_irq(&spidev->spi_lock); | |
814a8d50 | 788 | |
25d5cb4b DB |
789 | /* prevent new opens */ |
790 | mutex_lock(&device_list_lock); | |
814a8d50 | 791 | list_del(&spidev->device_entry); |
b2c8dadd DB |
792 | device_destroy(spidev_class, spidev->devt); |
793 | clear_bit(MINOR(spidev->devt), minors); | |
794 | if (spidev->users == 0) | |
795 | kfree(spidev); | |
814a8d50 AP |
796 | mutex_unlock(&device_list_lock); |
797 | ||
798 | return 0; | |
799 | } | |
800 | ||
db389b61 | 801 | static struct spi_driver spidev_spi_driver = { |
814a8d50 AP |
802 | .driver = { |
803 | .name = "spidev", | |
880cfd43 | 804 | .of_match_table = of_match_ptr(spidev_dt_ids), |
cf9f4327 | 805 | .acpi_match_table = ACPI_PTR(spidev_acpi_ids), |
814a8d50 AP |
806 | }, |
807 | .probe = spidev_probe, | |
fd4a319b | 808 | .remove = spidev_remove, |
814a8d50 AP |
809 | |
810 | /* NOTE: suspend/resume methods are not necessary here. | |
811 | * We don't do anything except pass the requests to/from | |
812 | * the underlying controller. The refrigerator handles | |
813 | * most issues; the controller driver handles the rest. | |
814 | */ | |
815 | }; | |
816 | ||
817 | /*-------------------------------------------------------------------------*/ | |
818 | ||
819 | static int __init spidev_init(void) | |
820 | { | |
821 | int status; | |
822 | ||
823 | /* Claim our 256 reserved device numbers. Then register a class | |
824 | * that will key udev/mdev to add/remove /dev nodes. Last, register | |
825 | * the driver which manages those device numbers. | |
826 | */ | |
827 | BUILD_BUG_ON(N_SPI_MINORS > 256); | |
828 | status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops); | |
829 | if (status < 0) | |
830 | return status; | |
831 | ||
b2c8dadd DB |
832 | spidev_class = class_create(THIS_MODULE, "spidev"); |
833 | if (IS_ERR(spidev_class)) { | |
db389b61 | 834 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
b2c8dadd | 835 | return PTR_ERR(spidev_class); |
814a8d50 AP |
836 | } |
837 | ||
db389b61 | 838 | status = spi_register_driver(&spidev_spi_driver); |
814a8d50 | 839 | if (status < 0) { |
b2c8dadd | 840 | class_destroy(spidev_class); |
db389b61 | 841 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
814a8d50 AP |
842 | } |
843 | return status; | |
844 | } | |
845 | module_init(spidev_init); | |
846 | ||
847 | static void __exit spidev_exit(void) | |
848 | { | |
db389b61 | 849 | spi_unregister_driver(&spidev_spi_driver); |
b2c8dadd | 850 | class_destroy(spidev_class); |
db389b61 | 851 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
814a8d50 AP |
852 | } |
853 | module_exit(spidev_exit); | |
854 | ||
855 | MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>"); | |
856 | MODULE_DESCRIPTION("User mode SPI device interface"); | |
857 | MODULE_LICENSE("GPL"); | |
e0626e38 | 858 | MODULE_ALIAS("spi:spidev"); |