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Commit | Line | Data |
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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
814a8d50 | 2 | /* |
ca632f55 | 3 | * Simple synchronous userspace interface to SPI devices |
814a8d50 AP |
4 | * |
5 | * Copyright (C) 2006 SWAPP | |
6 | * Andrea Paterniani <a.paterniani@swapp-eng.it> | |
7 | * Copyright (C) 2007 David Brownell (simplification, cleanup) | |
814a8d50 AP |
8 | */ |
9 | ||
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> | |
b2c8dadd | 15 | #include <linux/err.h> |
814a8d50 AP |
16 | #include <linux/list.h> |
17 | #include <linux/errno.h> | |
18 | #include <linux/mutex.h> | |
19 | #include <linux/slab.h> | |
7d48ec36 | 20 | #include <linux/compat.h> |
880cfd43 MR |
21 | #include <linux/of.h> |
22 | #include <linux/of_device.h> | |
cf9f4327 | 23 | #include <linux/acpi.h> |
814a8d50 AP |
24 | |
25 | #include <linux/spi/spi.h> | |
26 | #include <linux/spi/spidev.h> | |
27 | ||
95c63cfb | 28 | #include <linux/uaccess.h> |
814a8d50 AP |
29 | |
30 | ||
31 | /* | |
b595076a | 32 | * This supports access to SPI devices using normal userspace I/O calls. |
814a8d50 AP |
33 | * Note that while traditional UNIX/POSIX I/O semantics are half duplex, |
34 | * and often mask message boundaries, full SPI support requires full duplex | |
137f1188 | 35 | * transfers. There are several kinds of internal message boundaries to |
814a8d50 AP |
36 | * handle chipselect management and other protocol options. |
37 | * | |
38 | * SPI has a character major number assigned. We allocate minor numbers | |
39 | * dynamically using a bitmask. You must use hotplug tools, such as udev | |
40 | * (or mdev with busybox) to create and destroy the /dev/spidevB.C device | |
41 | * nodes, since there is no fixed association of minor numbers with any | |
42 | * particular SPI bus or device. | |
43 | */ | |
44 | #define SPIDEV_MAJOR 153 /* assigned */ | |
45 | #define N_SPI_MINORS 32 /* ... up to 256 */ | |
46 | ||
8ae1c924 | 47 | static DECLARE_BITMAP(minors, N_SPI_MINORS); |
814a8d50 AP |
48 | |
49 | ||
6f166e38 | 50 | /* Bit masks for spi_device.mode management. Note that incorrect |
b55f627f DB |
51 | * settings for some settings can cause *lots* of trouble for other |
52 | * devices on a shared bus: | |
6f166e38 | 53 | * |
b55f627f DB |
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. | |
59 | * | |
60 | * REVISIT should changing those flags be privileged? | |
6f166e38 AV |
61 | */ |
62 | #define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \ | |
b55f627f | 63 | | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \ |
dc64d39b | 64 | | SPI_NO_CS | SPI_READY | SPI_TX_DUAL \ |
66ec7b3b GU |
65 | | SPI_TX_QUAD | SPI_TX_OCTAL | SPI_RX_DUAL \ |
66 | | SPI_RX_QUAD | SPI_RX_OCTAL) | |
814a8d50 AP |
67 | |
68 | struct spidev_data { | |
b2c8dadd | 69 | dev_t devt; |
25d5cb4b | 70 | spinlock_t spi_lock; |
814a8d50 AP |
71 | struct spi_device *spi; |
72 | struct list_head device_entry; | |
73 | ||
865f6d19 | 74 | /* TX/RX buffers are NULL unless this device is open (users > 0) */ |
814a8d50 AP |
75 | struct mutex buf_lock; |
76 | unsigned users; | |
865f6d19 RJ |
77 | u8 *tx_buffer; |
78 | u8 *rx_buffer; | |
91690516 | 79 | u32 speed_hz; |
814a8d50 AP |
80 | }; |
81 | ||
82 | static LIST_HEAD(device_list); | |
83 | static DEFINE_MUTEX(device_list_lock); | |
84 | ||
85 | static unsigned bufsiz = 4096; | |
86 | module_param(bufsiz, uint, S_IRUGO); | |
87 | MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); | |
88 | ||
89 | /*-------------------------------------------------------------------------*/ | |
90 | ||
25d5cb4b DB |
91 | static ssize_t |
92 | spidev_sync(struct spidev_data *spidev, struct spi_message *message) | |
93 | { | |
25d5cb4b | 94 | int status; |
98d6f479 | 95 | struct spi_device *spi; |
25d5cb4b DB |
96 | |
97 | spin_lock_irq(&spidev->spi_lock); | |
98d6f479 MS |
98 | spi = spidev->spi; |
99 | spin_unlock_irq(&spidev->spi_lock); | |
100 | ||
101 | if (spi == NULL) | |
25d5cb4b DB |
102 | status = -ESHUTDOWN; |
103 | else | |
98d6f479 MS |
104 | status = spi_sync(spi, message); |
105 | ||
106 | if (status == 0) | |
107 | status = message->actual_length; | |
25d5cb4b | 108 | |
25d5cb4b DB |
109 | return status; |
110 | } | |
111 | ||
112 | static inline ssize_t | |
113 | spidev_sync_write(struct spidev_data *spidev, size_t len) | |
114 | { | |
115 | struct spi_transfer t = { | |
865f6d19 | 116 | .tx_buf = spidev->tx_buffer, |
25d5cb4b | 117 | .len = len, |
91690516 | 118 | .speed_hz = spidev->speed_hz, |
25d5cb4b DB |
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 | ||
127 | static inline ssize_t | |
128 | spidev_sync_read(struct spidev_data *spidev, size_t len) | |
129 | { | |
130 | struct spi_transfer t = { | |
865f6d19 | 131 | .rx_buf = spidev->rx_buffer, |
25d5cb4b | 132 | .len = len, |
91690516 | 133 | .speed_hz = spidev->speed_hz, |
25d5cb4b DB |
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 | ||
814a8d50 AP |
144 | /* Read-only message with current device setup */ |
145 | static ssize_t | |
146 | spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) | |
147 | { | |
148 | struct spidev_data *spidev; | |
814a8d50 AP |
149 | ssize_t status = 0; |
150 | ||
151 | /* chipselect only toggles at start or end of operation */ | |
152 | if (count > bufsiz) | |
153 | return -EMSGSIZE; | |
154 | ||
155 | spidev = filp->private_data; | |
814a8d50 AP |
156 | |
157 | mutex_lock(&spidev->buf_lock); | |
25d5cb4b | 158 | status = spidev_sync_read(spidev, count); |
4b1295b0 | 159 | if (status > 0) { |
814a8d50 AP |
160 | unsigned long missing; |
161 | ||
865f6d19 | 162 | missing = copy_to_user(buf, spidev->rx_buffer, status); |
4b1295b0 | 163 | if (missing == status) |
814a8d50 AP |
164 | status = -EFAULT; |
165 | else | |
4b1295b0 | 166 | status = status - missing; |
814a8d50 AP |
167 | } |
168 | mutex_unlock(&spidev->buf_lock); | |
169 | ||
170 | return status; | |
171 | } | |
172 | ||
173 | /* Write-only message with current device setup */ | |
174 | static ssize_t | |
175 | spidev_write(struct file *filp, const char __user *buf, | |
176 | size_t count, loff_t *f_pos) | |
177 | { | |
178 | struct spidev_data *spidev; | |
814a8d50 AP |
179 | ssize_t status = 0; |
180 | unsigned long missing; | |
181 | ||
182 | /* chipselect only toggles at start or end of operation */ | |
183 | if (count > bufsiz) | |
184 | return -EMSGSIZE; | |
185 | ||
186 | spidev = filp->private_data; | |
814a8d50 AP |
187 | |
188 | mutex_lock(&spidev->buf_lock); | |
865f6d19 | 189 | missing = copy_from_user(spidev->tx_buffer, buf, count); |
95c63cfb | 190 | if (missing == 0) |
25d5cb4b | 191 | status = spidev_sync_write(spidev, count); |
95c63cfb | 192 | else |
814a8d50 AP |
193 | status = -EFAULT; |
194 | mutex_unlock(&spidev->buf_lock); | |
195 | ||
196 | return status; | |
197 | } | |
198 | ||
199 | static 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; | |
9a12bff7 | 206 | unsigned n, total, tx_total, rx_total; |
865f6d19 | 207 | u8 *tx_buf, *rx_buf; |
814a8d50 AP |
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 | /* Construct spi_message, copying any tx data to bounce buffer. | |
216 | * We walk the array of user-provided transfers, using each one | |
217 | * to initialize a kernel version of the same transfer. | |
218 | */ | |
865f6d19 RJ |
219 | tx_buf = spidev->tx_buffer; |
220 | rx_buf = spidev->rx_buffer; | |
814a8d50 | 221 | total = 0; |
9a12bff7 IA |
222 | tx_total = 0; |
223 | rx_total = 0; | |
814a8d50 AP |
224 | for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; |
225 | n; | |
226 | n--, k_tmp++, u_tmp++) { | |
227 | k_tmp->len = u_tmp->len; | |
228 | ||
da90fa8f | 229 | total += k_tmp->len; |
9a12bff7 IA |
230 | /* Since the function returns the total length of transfers |
231 | * on success, restrict the total to positive int values to | |
f20fbaad IA |
232 | * avoid the return value looking like an error. Also check |
233 | * each transfer length to avoid arithmetic overflow. | |
9a12bff7 | 234 | */ |
f20fbaad | 235 | if (total > INT_MAX || k_tmp->len > INT_MAX) { |
da90fa8f DP |
236 | status = -EMSGSIZE; |
237 | goto done; | |
238 | } | |
239 | ||
814a8d50 | 240 | if (u_tmp->rx_buf) { |
9a12bff7 IA |
241 | /* this transfer needs space in RX bounce buffer */ |
242 | rx_total += k_tmp->len; | |
243 | if (rx_total > bufsiz) { | |
244 | status = -EMSGSIZE; | |
245 | goto done; | |
246 | } | |
865f6d19 | 247 | k_tmp->rx_buf = rx_buf; |
9a12bff7 | 248 | rx_buf += k_tmp->len; |
814a8d50 AP |
249 | } |
250 | if (u_tmp->tx_buf) { | |
9a12bff7 IA |
251 | /* this transfer needs space in TX bounce buffer */ |
252 | tx_total += k_tmp->len; | |
253 | if (tx_total > bufsiz) { | |
254 | status = -EMSGSIZE; | |
255 | goto done; | |
256 | } | |
865f6d19 RJ |
257 | k_tmp->tx_buf = tx_buf; |
258 | if (copy_from_user(tx_buf, (const u8 __user *) | |
142956af | 259 | (uintptr_t) u_tmp->tx_buf, |
814a8d50 AP |
260 | u_tmp->len)) |
261 | goto done; | |
9a12bff7 | 262 | tx_buf += k_tmp->len; |
814a8d50 | 263 | } |
814a8d50 AP |
264 | |
265 | k_tmp->cs_change = !!u_tmp->cs_change; | |
dc64d39b GU |
266 | k_tmp->tx_nbits = u_tmp->tx_nbits; |
267 | k_tmp->rx_nbits = u_tmp->rx_nbits; | |
814a8d50 | 268 | k_tmp->bits_per_word = u_tmp->bits_per_word; |
8e319dd5 AA |
269 | k_tmp->delay.value = u_tmp->delay_usecs; |
270 | k_tmp->delay.unit = SPI_DELAY_UNIT_USECS; | |
814a8d50 | 271 | k_tmp->speed_hz = u_tmp->speed_hz; |
ec3fa72f AA |
272 | k_tmp->word_delay.value = u_tmp->word_delay_usecs; |
273 | k_tmp->word_delay.unit = SPI_DELAY_UNIT_USECS; | |
91690516 MB |
274 | if (!k_tmp->speed_hz) |
275 | k_tmp->speed_hz = spidev->speed_hz; | |
814a8d50 | 276 | #ifdef VERBOSE |
41df70d9 | 277 | dev_dbg(&spidev->spi->dev, |
2ed6692e | 278 | " xfer len %u %s%s%s%dbits %u usec %u usec %uHz\n", |
ea70fb5b OS |
279 | k_tmp->len, |
280 | k_tmp->rx_buf ? "rx " : "", | |
281 | k_tmp->tx_buf ? "tx " : "", | |
282 | k_tmp->cs_change ? "cs " : "", | |
283 | k_tmp->bits_per_word ? : spidev->spi->bits_per_word, | |
284 | k_tmp->delay.value, | |
285 | k_tmp->word_delay.value, | |
286 | k_tmp->speed_hz ? : spidev->spi->max_speed_hz); | |
814a8d50 AP |
287 | #endif |
288 | spi_message_add_tail(k_tmp, &msg); | |
289 | } | |
290 | ||
25d5cb4b | 291 | status = spidev_sync(spidev, &msg); |
814a8d50 AP |
292 | if (status < 0) |
293 | goto done; | |
294 | ||
295 | /* copy any rx data out of bounce buffer */ | |
865f6d19 | 296 | rx_buf = spidev->rx_buffer; |
814a8d50 AP |
297 | for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { |
298 | if (u_tmp->rx_buf) { | |
251d5951 | 299 | if (copy_to_user((u8 __user *) |
865f6d19 | 300 | (uintptr_t) u_tmp->rx_buf, rx_buf, |
814a8d50 AP |
301 | u_tmp->len)) { |
302 | status = -EFAULT; | |
303 | goto done; | |
304 | } | |
9a12bff7 | 305 | rx_buf += u_tmp->len; |
814a8d50 | 306 | } |
814a8d50 AP |
307 | } |
308 | status = total; | |
309 | ||
310 | done: | |
814a8d50 AP |
311 | kfree(k_xfers); |
312 | return status; | |
313 | } | |
314 | ||
7782a1a9 IA |
315 | static struct spi_ioc_transfer * |
316 | spidev_get_ioc_message(unsigned int cmd, struct spi_ioc_transfer __user *u_ioc, | |
317 | unsigned *n_ioc) | |
318 | { | |
7782a1a9 IA |
319 | u32 tmp; |
320 | ||
321 | /* Check type, command number and direction */ | |
322 | if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC | |
323 | || _IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0)) | |
324 | || _IOC_DIR(cmd) != _IOC_WRITE) | |
325 | return ERR_PTR(-ENOTTY); | |
326 | ||
327 | tmp = _IOC_SIZE(cmd); | |
328 | if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) | |
329 | return ERR_PTR(-EINVAL); | |
330 | *n_ioc = tmp / sizeof(struct spi_ioc_transfer); | |
331 | if (*n_ioc == 0) | |
332 | return NULL; | |
333 | ||
334 | /* copy into scratch area */ | |
f7929436 | 335 | return memdup_user(u_ioc, tmp); |
7782a1a9 IA |
336 | } |
337 | ||
4ef754b7 AC |
338 | static long |
339 | spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
814a8d50 | 340 | { |
814a8d50 AP |
341 | int retval = 0; |
342 | struct spidev_data *spidev; | |
343 | struct spi_device *spi; | |
344 | u32 tmp; | |
345 | unsigned n_ioc; | |
346 | struct spi_ioc_transfer *ioc; | |
347 | ||
348 | /* Check type and command number */ | |
349 | if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC) | |
350 | return -ENOTTY; | |
351 | ||
25d5cb4b DB |
352 | /* guard against device removal before, or while, |
353 | * we issue this ioctl. | |
354 | */ | |
814a8d50 | 355 | spidev = filp->private_data; |
25d5cb4b DB |
356 | spin_lock_irq(&spidev->spi_lock); |
357 | spi = spi_dev_get(spidev->spi); | |
358 | spin_unlock_irq(&spidev->spi_lock); | |
359 | ||
360 | if (spi == NULL) | |
361 | return -ESHUTDOWN; | |
814a8d50 | 362 | |
4ef754b7 AC |
363 | /* use the buffer lock here for triple duty: |
364 | * - prevent I/O (from us) so calling spi_setup() is safe; | |
365 | * - prevent concurrent SPI_IOC_WR_* from morphing | |
366 | * data fields while SPI_IOC_RD_* reads them; | |
367 | * - SPI_IOC_MESSAGE needs the buffer locked "normally". | |
368 | */ | |
369 | mutex_lock(&spidev->buf_lock); | |
370 | ||
814a8d50 AP |
371 | switch (cmd) { |
372 | /* read requests */ | |
373 | case SPI_IOC_RD_MODE: | |
251d5951 | 374 | retval = put_user(spi->mode & SPI_MODE_MASK, |
814a8d50 AP |
375 | (__u8 __user *)arg); |
376 | break; | |
dc64d39b | 377 | case SPI_IOC_RD_MODE32: |
251d5951 | 378 | retval = put_user(spi->mode & SPI_MODE_MASK, |
dc64d39b GU |
379 | (__u32 __user *)arg); |
380 | break; | |
814a8d50 | 381 | case SPI_IOC_RD_LSB_FIRST: |
251d5951 | 382 | retval = put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0, |
814a8d50 AP |
383 | (__u8 __user *)arg); |
384 | break; | |
385 | case SPI_IOC_RD_BITS_PER_WORD: | |
251d5951 | 386 | retval = put_user(spi->bits_per_word, (__u8 __user *)arg); |
814a8d50 AP |
387 | break; |
388 | case SPI_IOC_RD_MAX_SPEED_HZ: | |
251d5951 | 389 | retval = put_user(spidev->speed_hz, (__u32 __user *)arg); |
814a8d50 AP |
390 | break; |
391 | ||
392 | /* write requests */ | |
393 | case SPI_IOC_WR_MODE: | |
dc64d39b GU |
394 | case SPI_IOC_WR_MODE32: |
395 | if (cmd == SPI_IOC_WR_MODE) | |
251d5951 | 396 | retval = get_user(tmp, (u8 __user *)arg); |
dc64d39b | 397 | else |
251d5951 | 398 | retval = get_user(tmp, (u32 __user *)arg); |
814a8d50 | 399 | if (retval == 0) { |
138c9c32 | 400 | struct spi_controller *ctlr = spi->controller; |
e6456186 | 401 | u32 save = spi->mode; |
814a8d50 AP |
402 | |
403 | if (tmp & ~SPI_MODE_MASK) { | |
404 | retval = -EINVAL; | |
405 | break; | |
406 | } | |
407 | ||
138c9c32 LW |
408 | if (ctlr->use_gpio_descriptors && ctlr->cs_gpiods && |
409 | ctlr->cs_gpiods[spi->chip_select]) | |
410 | tmp |= SPI_CS_HIGH; | |
411 | ||
814a8d50 | 412 | tmp |= spi->mode & ~SPI_MODE_MASK; |
dc64d39b | 413 | spi->mode = (u16)tmp; |
814a8d50 AP |
414 | retval = spi_setup(spi); |
415 | if (retval < 0) | |
416 | spi->mode = save; | |
417 | else | |
dc64d39b | 418 | dev_dbg(&spi->dev, "spi mode %x\n", tmp); |
814a8d50 AP |
419 | } |
420 | break; | |
421 | case SPI_IOC_WR_LSB_FIRST: | |
251d5951 | 422 | retval = get_user(tmp, (__u8 __user *)arg); |
814a8d50 | 423 | if (retval == 0) { |
e6456186 | 424 | u32 save = spi->mode; |
814a8d50 AP |
425 | |
426 | if (tmp) | |
427 | spi->mode |= SPI_LSB_FIRST; | |
428 | else | |
429 | spi->mode &= ~SPI_LSB_FIRST; | |
430 | retval = spi_setup(spi); | |
431 | if (retval < 0) | |
432 | spi->mode = save; | |
433 | else | |
434 | dev_dbg(&spi->dev, "%csb first\n", | |
435 | tmp ? 'l' : 'm'); | |
436 | } | |
437 | break; | |
438 | case SPI_IOC_WR_BITS_PER_WORD: | |
251d5951 | 439 | retval = get_user(tmp, (__u8 __user *)arg); |
814a8d50 AP |
440 | if (retval == 0) { |
441 | u8 save = spi->bits_per_word; | |
442 | ||
443 | spi->bits_per_word = tmp; | |
444 | retval = spi_setup(spi); | |
445 | if (retval < 0) | |
446 | spi->bits_per_word = save; | |
447 | else | |
448 | dev_dbg(&spi->dev, "%d bits per word\n", tmp); | |
449 | } | |
450 | break; | |
451 | case SPI_IOC_WR_MAX_SPEED_HZ: | |
251d5951 | 452 | retval = get_user(tmp, (__u32 __user *)arg); |
814a8d50 AP |
453 | if (retval == 0) { |
454 | u32 save = spi->max_speed_hz; | |
455 | ||
456 | spi->max_speed_hz = tmp; | |
457 | retval = spi_setup(spi); | |
4276fc82 | 458 | if (retval == 0) { |
91690516 | 459 | spidev->speed_hz = tmp; |
4276fc82 OS |
460 | dev_dbg(&spi->dev, "%d Hz (max)\n", |
461 | spidev->speed_hz); | |
462 | } | |
91690516 | 463 | spi->max_speed_hz = save; |
814a8d50 AP |
464 | } |
465 | break; | |
466 | ||
467 | default: | |
468 | /* segmented and/or full-duplex I/O request */ | |
7782a1a9 IA |
469 | /* Check message and copy into scratch area */ |
470 | ioc = spidev_get_ioc_message(cmd, | |
471 | (struct spi_ioc_transfer __user *)arg, &n_ioc); | |
472 | if (IS_ERR(ioc)) { | |
473 | retval = PTR_ERR(ioc); | |
814a8d50 AP |
474 | break; |
475 | } | |
7782a1a9 IA |
476 | if (!ioc) |
477 | break; /* n_ioc is also 0 */ | |
814a8d50 AP |
478 | |
479 | /* translate to spi_message, execute */ | |
480 | retval = spidev_message(spidev, ioc, n_ioc); | |
481 | kfree(ioc); | |
482 | break; | |
483 | } | |
4ef754b7 AC |
484 | |
485 | mutex_unlock(&spidev->buf_lock); | |
25d5cb4b | 486 | spi_dev_put(spi); |
814a8d50 AP |
487 | return retval; |
488 | } | |
489 | ||
7d48ec36 | 490 | #ifdef CONFIG_COMPAT |
7782a1a9 IA |
491 | static long |
492 | spidev_compat_ioc_message(struct file *filp, unsigned int cmd, | |
493 | unsigned long arg) | |
494 | { | |
495 | struct spi_ioc_transfer __user *u_ioc; | |
496 | int retval = 0; | |
497 | struct spidev_data *spidev; | |
498 | struct spi_device *spi; | |
499 | unsigned n_ioc, n; | |
500 | struct spi_ioc_transfer *ioc; | |
501 | ||
502 | u_ioc = (struct spi_ioc_transfer __user *) compat_ptr(arg); | |
7782a1a9 IA |
503 | |
504 | /* guard against device removal before, or while, | |
505 | * we issue this ioctl. | |
506 | */ | |
507 | spidev = filp->private_data; | |
508 | spin_lock_irq(&spidev->spi_lock); | |
509 | spi = spi_dev_get(spidev->spi); | |
510 | spin_unlock_irq(&spidev->spi_lock); | |
511 | ||
512 | if (spi == NULL) | |
513 | return -ESHUTDOWN; | |
514 | ||
515 | /* SPI_IOC_MESSAGE needs the buffer locked "normally" */ | |
516 | mutex_lock(&spidev->buf_lock); | |
517 | ||
518 | /* Check message and copy into scratch area */ | |
519 | ioc = spidev_get_ioc_message(cmd, u_ioc, &n_ioc); | |
520 | if (IS_ERR(ioc)) { | |
521 | retval = PTR_ERR(ioc); | |
522 | goto done; | |
523 | } | |
524 | if (!ioc) | |
525 | goto done; /* n_ioc is also 0 */ | |
526 | ||
527 | /* Convert buffer pointers */ | |
528 | for (n = 0; n < n_ioc; n++) { | |
529 | ioc[n].rx_buf = (uintptr_t) compat_ptr(ioc[n].rx_buf); | |
530 | ioc[n].tx_buf = (uintptr_t) compat_ptr(ioc[n].tx_buf); | |
531 | } | |
532 | ||
533 | /* translate to spi_message, execute */ | |
534 | retval = spidev_message(spidev, ioc, n_ioc); | |
535 | kfree(ioc); | |
536 | ||
537 | done: | |
538 | mutex_unlock(&spidev->buf_lock); | |
539 | spi_dev_put(spi); | |
540 | return retval; | |
541 | } | |
542 | ||
7d48ec36 BW |
543 | static long |
544 | spidev_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) | |
545 | { | |
7782a1a9 IA |
546 | if (_IOC_TYPE(cmd) == SPI_IOC_MAGIC |
547 | && _IOC_NR(cmd) == _IOC_NR(SPI_IOC_MESSAGE(0)) | |
548 | && _IOC_DIR(cmd) == _IOC_WRITE) | |
549 | return spidev_compat_ioc_message(filp, cmd, arg); | |
550 | ||
7d48ec36 BW |
551 | return spidev_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); |
552 | } | |
553 | #else | |
554 | #define spidev_compat_ioctl NULL | |
555 | #endif /* CONFIG_COMPAT */ | |
556 | ||
814a8d50 AP |
557 | static int spidev_open(struct inode *inode, struct file *filp) |
558 | { | |
559 | struct spidev_data *spidev; | |
560 | int status = -ENXIO; | |
561 | ||
562 | mutex_lock(&device_list_lock); | |
563 | ||
564 | list_for_each_entry(spidev, &device_list, device_entry) { | |
b2c8dadd | 565 | if (spidev->devt == inode->i_rdev) { |
814a8d50 AP |
566 | status = 0; |
567 | break; | |
568 | } | |
569 | } | |
865f6d19 RJ |
570 | |
571 | if (status) { | |
572 | pr_debug("spidev: nothing for minor %d\n", iminor(inode)); | |
573 | goto err_find_dev; | |
574 | } | |
575 | ||
576 | if (!spidev->tx_buffer) { | |
577 | spidev->tx_buffer = kmalloc(bufsiz, GFP_KERNEL); | |
578 | if (!spidev->tx_buffer) { | |
89a63566 CIK |
579 | dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); |
580 | status = -ENOMEM; | |
865f6d19 | 581 | goto err_find_dev; |
814a8d50 | 582 | } |
89a63566 | 583 | } |
865f6d19 RJ |
584 | |
585 | if (!spidev->rx_buffer) { | |
586 | spidev->rx_buffer = kmalloc(bufsiz, GFP_KERNEL); | |
587 | if (!spidev->rx_buffer) { | |
588 | dev_dbg(&spidev->spi->dev, "open/ENOMEM\n"); | |
589 | status = -ENOMEM; | |
590 | goto err_alloc_rx_buf; | |
814a8d50 | 591 | } |
865f6d19 RJ |
592 | } |
593 | ||
594 | spidev->users++; | |
595 | filp->private_data = spidev; | |
c5bf68fe | 596 | stream_open(inode, filp); |
814a8d50 | 597 | |
865f6d19 RJ |
598 | mutex_unlock(&device_list_lock); |
599 | return 0; | |
600 | ||
601 | err_alloc_rx_buf: | |
602 | kfree(spidev->tx_buffer); | |
603 | spidev->tx_buffer = NULL; | |
604 | err_find_dev: | |
814a8d50 AP |
605 | mutex_unlock(&device_list_lock); |
606 | return status; | |
607 | } | |
608 | ||
609 | static int spidev_release(struct inode *inode, struct file *filp) | |
610 | { | |
611 | struct spidev_data *spidev; | |
814a8d50 AP |
612 | |
613 | mutex_lock(&device_list_lock); | |
614 | spidev = filp->private_data; | |
615 | filp->private_data = NULL; | |
b2c8dadd DB |
616 | |
617 | /* last close? */ | |
814a8d50 AP |
618 | spidev->users--; |
619 | if (!spidev->users) { | |
b2c8dadd DB |
620 | int dofree; |
621 | ||
865f6d19 RJ |
622 | kfree(spidev->tx_buffer); |
623 | spidev->tx_buffer = NULL; | |
624 | ||
625 | kfree(spidev->rx_buffer); | |
626 | spidev->rx_buffer = NULL; | |
b2c8dadd | 627 | |
56ea1075 | 628 | spin_lock_irq(&spidev->spi_lock); |
dd85ebf6 SM |
629 | if (spidev->spi) |
630 | spidev->speed_hz = spidev->spi->max_speed_hz; | |
91690516 | 631 | |
b2c8dadd | 632 | /* ... after we unbound from the underlying device? */ |
b2c8dadd DB |
633 | dofree = (spidev->spi == NULL); |
634 | spin_unlock_irq(&spidev->spi_lock); | |
635 | ||
636 | if (dofree) | |
637 | kfree(spidev); | |
814a8d50 | 638 | } |
9f918a72 LM |
639 | #ifdef CONFIG_SPI_SLAVE |
640 | spi_slave_abort(spidev->spi); | |
641 | #endif | |
814a8d50 AP |
642 | mutex_unlock(&device_list_lock); |
643 | ||
99472cc0 | 644 | return 0; |
814a8d50 AP |
645 | } |
646 | ||
828c0950 | 647 | static const struct file_operations spidev_fops = { |
814a8d50 AP |
648 | .owner = THIS_MODULE, |
649 | /* REVISIT switch to aio primitives, so that userspace | |
650 | * gets more complete API coverage. It'll simplify things | |
651 | * too, except for the locking. | |
652 | */ | |
653 | .write = spidev_write, | |
654 | .read = spidev_read, | |
4ef754b7 | 655 | .unlocked_ioctl = spidev_ioctl, |
7d48ec36 | 656 | .compat_ioctl = spidev_compat_ioctl, |
814a8d50 AP |
657 | .open = spidev_open, |
658 | .release = spidev_release, | |
6038f373 | 659 | .llseek = no_llseek, |
814a8d50 AP |
660 | }; |
661 | ||
662 | /*-------------------------------------------------------------------------*/ | |
663 | ||
664 | /* The main reason to have this class is to make mdev/udev create the | |
665 | * /dev/spidevB.C character device nodes exposing our userspace API. | |
666 | * It also simplifies memory management. | |
667 | */ | |
668 | ||
b2c8dadd | 669 | static struct class *spidev_class; |
814a8d50 | 670 | |
956b200a MB |
671 | #ifdef CONFIG_OF |
672 | static const struct of_device_id spidev_dt_ids[] = { | |
673 | { .compatible = "rohm,dh2228fv" }, | |
6fec919b | 674 | { .compatible = "lineartechnology,ltc2488" }, |
144235ea | 675 | { .compatible = "ge,achc" }, |
91b46346 | 676 | { .compatible = "semtech,sx1301" }, |
5e9feb35 | 677 | { .compatible = "lwn,bk4" }, |
9783da23 | 678 | { .compatible = "dh,dhcom-board" }, |
c6e2d2c7 | 679 | { .compatible = "menlo,m53cpld" }, |
956b200a MB |
680 | {}, |
681 | }; | |
682 | MODULE_DEVICE_TABLE(of, spidev_dt_ids); | |
683 | #endif | |
684 | ||
cf9f4327 MW |
685 | #ifdef CONFIG_ACPI |
686 | ||
687 | /* Dummy SPI devices not to be used in production systems */ | |
688 | #define SPIDEV_ACPI_DUMMY 1 | |
689 | ||
690 | static const struct acpi_device_id spidev_acpi_ids[] = { | |
691 | /* | |
692 | * The ACPI SPT000* devices are only meant for development and | |
693 | * testing. Systems used in production should have a proper ACPI | |
694 | * description of the connected peripheral and they should also use | |
695 | * a proper driver instead of poking directly to the SPI bus. | |
696 | */ | |
697 | { "SPT0001", SPIDEV_ACPI_DUMMY }, | |
698 | { "SPT0002", SPIDEV_ACPI_DUMMY }, | |
699 | { "SPT0003", SPIDEV_ACPI_DUMMY }, | |
700 | {}, | |
701 | }; | |
702 | MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids); | |
703 | ||
704 | static void spidev_probe_acpi(struct spi_device *spi) | |
705 | { | |
706 | const struct acpi_device_id *id; | |
707 | ||
708 | if (!has_acpi_companion(&spi->dev)) | |
709 | return; | |
710 | ||
711 | id = acpi_match_device(spidev_acpi_ids, &spi->dev); | |
712 | if (WARN_ON(!id)) | |
713 | return; | |
714 | ||
715 | if (id->driver_data == SPIDEV_ACPI_DUMMY) | |
716 | dev_warn(&spi->dev, "do not use this driver in production systems!\n"); | |
717 | } | |
718 | #else | |
719 | static inline void spidev_probe_acpi(struct spi_device *spi) {} | |
720 | #endif | |
721 | ||
814a8d50 AP |
722 | /*-------------------------------------------------------------------------*/ |
723 | ||
fd4a319b | 724 | static int spidev_probe(struct spi_device *spi) |
814a8d50 AP |
725 | { |
726 | struct spidev_data *spidev; | |
727 | int status; | |
728 | unsigned long minor; | |
729 | ||
956b200a MB |
730 | /* |
731 | * spidev should never be referenced in DT without a specific | |
ffe22888 | 732 | * compatible string, it is a Linux implementation thing |
956b200a MB |
733 | * rather than a description of the hardware. |
734 | */ | |
605b3bec TP |
735 | WARN(spi->dev.of_node && |
736 | of_device_is_compatible(spi->dev.of_node, "spidev"), | |
737 | "%pOF: buggy DT: spidev listed directly in DT\n", spi->dev.of_node); | |
956b200a | 738 | |
cf9f4327 MW |
739 | spidev_probe_acpi(spi); |
740 | ||
814a8d50 AP |
741 | /* Allocate driver data */ |
742 | spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); | |
743 | if (!spidev) | |
744 | return -ENOMEM; | |
745 | ||
746 | /* Initialize the driver data */ | |
747 | spidev->spi = spi; | |
25d5cb4b | 748 | spin_lock_init(&spidev->spi_lock); |
814a8d50 AP |
749 | mutex_init(&spidev->buf_lock); |
750 | ||
751 | INIT_LIST_HEAD(&spidev->device_entry); | |
752 | ||
753 | /* If we can allocate a minor number, hook up this device. | |
754 | * Reusing minors is fine so long as udev or mdev is working. | |
755 | */ | |
756 | mutex_lock(&device_list_lock); | |
0a4dd778 | 757 | minor = find_first_zero_bit(minors, N_SPI_MINORS); |
814a8d50 | 758 | if (minor < N_SPI_MINORS) { |
b2c8dadd DB |
759 | struct device *dev; |
760 | ||
761 | spidev->devt = MKDEV(SPIDEV_MAJOR, minor); | |
a9b12619 GKH |
762 | dev = device_create(spidev_class, &spi->dev, spidev->devt, |
763 | spidev, "spidev%d.%d", | |
764 | spi->master->bus_num, spi->chip_select); | |
8c6ffba0 | 765 | status = PTR_ERR_OR_ZERO(dev); |
814a8d50 AP |
766 | } else { |
767 | dev_dbg(&spi->dev, "no minor number available!\n"); | |
768 | status = -ENODEV; | |
769 | } | |
770 | if (status == 0) { | |
771 | set_bit(minor, minors); | |
814a8d50 AP |
772 | list_add(&spidev->device_entry, &device_list); |
773 | } | |
774 | mutex_unlock(&device_list_lock); | |
775 | ||
91690516 MB |
776 | spidev->speed_hz = spi->max_speed_hz; |
777 | ||
aaacf4bb WO |
778 | if (status == 0) |
779 | spi_set_drvdata(spi, spidev); | |
780 | else | |
814a8d50 AP |
781 | kfree(spidev); |
782 | ||
783 | return status; | |
784 | } | |
785 | ||
fd4a319b | 786 | static int spidev_remove(struct spi_device *spi) |
814a8d50 | 787 | { |
b2c8dadd | 788 | struct spidev_data *spidev = spi_get_drvdata(spi); |
814a8d50 | 789 | |
25d5cb4b DB |
790 | /* make sure ops on existing fds can abort cleanly */ |
791 | spin_lock_irq(&spidev->spi_lock); | |
792 | spidev->spi = NULL; | |
793 | spin_unlock_irq(&spidev->spi_lock); | |
814a8d50 | 794 | |
25d5cb4b DB |
795 | /* prevent new opens */ |
796 | mutex_lock(&device_list_lock); | |
814a8d50 | 797 | list_del(&spidev->device_entry); |
b2c8dadd DB |
798 | device_destroy(spidev_class, spidev->devt); |
799 | clear_bit(MINOR(spidev->devt), minors); | |
800 | if (spidev->users == 0) | |
801 | kfree(spidev); | |
814a8d50 AP |
802 | mutex_unlock(&device_list_lock); |
803 | ||
804 | return 0; | |
805 | } | |
806 | ||
db389b61 | 807 | static struct spi_driver spidev_spi_driver = { |
814a8d50 AP |
808 | .driver = { |
809 | .name = "spidev", | |
880cfd43 | 810 | .of_match_table = of_match_ptr(spidev_dt_ids), |
cf9f4327 | 811 | .acpi_match_table = ACPI_PTR(spidev_acpi_ids), |
814a8d50 AP |
812 | }, |
813 | .probe = spidev_probe, | |
fd4a319b | 814 | .remove = spidev_remove, |
814a8d50 AP |
815 | |
816 | /* NOTE: suspend/resume methods are not necessary here. | |
817 | * We don't do anything except pass the requests to/from | |
818 | * the underlying controller. The refrigerator handles | |
819 | * most issues; the controller driver handles the rest. | |
820 | */ | |
821 | }; | |
822 | ||
823 | /*-------------------------------------------------------------------------*/ | |
824 | ||
825 | static int __init spidev_init(void) | |
826 | { | |
827 | int status; | |
828 | ||
829 | /* Claim our 256 reserved device numbers. Then register a class | |
830 | * that will key udev/mdev to add/remove /dev nodes. Last, register | |
831 | * the driver which manages those device numbers. | |
832 | */ | |
833 | BUILD_BUG_ON(N_SPI_MINORS > 256); | |
834 | status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops); | |
835 | if (status < 0) | |
836 | return status; | |
837 | ||
b2c8dadd DB |
838 | spidev_class = class_create(THIS_MODULE, "spidev"); |
839 | if (IS_ERR(spidev_class)) { | |
db389b61 | 840 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
b2c8dadd | 841 | return PTR_ERR(spidev_class); |
814a8d50 AP |
842 | } |
843 | ||
db389b61 | 844 | status = spi_register_driver(&spidev_spi_driver); |
814a8d50 | 845 | if (status < 0) { |
b2c8dadd | 846 | class_destroy(spidev_class); |
db389b61 | 847 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
814a8d50 AP |
848 | } |
849 | return status; | |
850 | } | |
851 | module_init(spidev_init); | |
852 | ||
853 | static void __exit spidev_exit(void) | |
854 | { | |
db389b61 | 855 | spi_unregister_driver(&spidev_spi_driver); |
b2c8dadd | 856 | class_destroy(spidev_class); |
db389b61 | 857 | unregister_chrdev(SPIDEV_MAJOR, spidev_spi_driver.driver.name); |
814a8d50 AP |
858 | } |
859 | module_exit(spidev_exit); | |
860 | ||
861 | MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>"); | |
862 | MODULE_DESCRIPTION("User mode SPI device interface"); | |
863 | MODULE_LICENSE("GPL"); | |
e0626e38 | 864 | MODULE_ALIAS("spi:spidev"); |