Commit | Line | Data |
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7026ea4b JC |
1 | /* The industrial I/O core |
2 | * | |
3 | * Copyright (c) 2008 Jonathan Cameron | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License version 2 as published by | |
7 | * the Free Software Foundation. | |
8 | * | |
14555b14 | 9 | * Handling of buffer allocation / resizing. |
7026ea4b JC |
10 | * |
11 | * | |
12 | * Things to look at here. | |
13 | * - Better memory allocation techniques? | |
14 | * - Alternative access techniques? | |
15 | */ | |
16 | #include <linux/kernel.h> | |
8e336a72 | 17 | #include <linux/export.h> |
7026ea4b | 18 | #include <linux/device.h> |
7026ea4b | 19 | #include <linux/fs.h> |
7026ea4b | 20 | #include <linux/cdev.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
a7348347 | 22 | #include <linux/poll.h> |
d2f0a48f | 23 | #include <linux/sched.h> |
7026ea4b | 24 | |
06458e27 | 25 | #include <linux/iio/iio.h> |
df9c1c42 | 26 | #include "iio_core.h" |
06458e27 JC |
27 | #include <linux/iio/sysfs.h> |
28 | #include <linux/iio/buffer.h> | |
7026ea4b | 29 | |
8310b86c JC |
30 | static const char * const iio_endian_prefix[] = { |
31 | [IIO_BE] = "be", | |
32 | [IIO_LE] = "le", | |
33 | }; | |
7026ea4b | 34 | |
705ee2c9 | 35 | static bool iio_buffer_is_active(struct iio_buffer *buf) |
84b36ce5 | 36 | { |
705ee2c9 | 37 | return !list_empty(&buf->buffer_list); |
84b36ce5 JC |
38 | } |
39 | ||
647cc7b9 LPC |
40 | static bool iio_buffer_data_available(struct iio_buffer *buf) |
41 | { | |
42 | if (buf->access->data_available) | |
43 | return buf->access->data_available(buf); | |
44 | ||
45 | return buf->stufftoread; | |
46 | } | |
47 | ||
7026ea4b | 48 | /** |
14555b14 | 49 | * iio_buffer_read_first_n_outer() - chrdev read for buffer access |
7026ea4b | 50 | * |
14555b14 JC |
51 | * This function relies on all buffer implementations having an |
52 | * iio_buffer as their first element. | |
7026ea4b | 53 | **/ |
14555b14 JC |
54 | ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, |
55 | size_t n, loff_t *f_ps) | |
7026ea4b | 56 | { |
1aa04278 | 57 | struct iio_dev *indio_dev = filp->private_data; |
14555b14 | 58 | struct iio_buffer *rb = indio_dev->buffer; |
d5857d65 | 59 | |
f18e7a06 LPC |
60 | if (!indio_dev->info) |
61 | return -ENODEV; | |
62 | ||
96e00f11 | 63 | if (!rb || !rb->access->read_first_n) |
7026ea4b | 64 | return -EINVAL; |
8d213f24 | 65 | return rb->access->read_first_n(rb, n, buf); |
7026ea4b JC |
66 | } |
67 | ||
a7348347 | 68 | /** |
14555b14 | 69 | * iio_buffer_poll() - poll the buffer to find out if it has data |
a7348347 | 70 | */ |
14555b14 JC |
71 | unsigned int iio_buffer_poll(struct file *filp, |
72 | struct poll_table_struct *wait) | |
a7348347 | 73 | { |
1aa04278 | 74 | struct iio_dev *indio_dev = filp->private_data; |
14555b14 | 75 | struct iio_buffer *rb = indio_dev->buffer; |
a7348347 | 76 | |
f18e7a06 LPC |
77 | if (!indio_dev->info) |
78 | return -ENODEV; | |
79 | ||
a7348347 | 80 | poll_wait(filp, &rb->pollq, wait); |
647cc7b9 | 81 | if (iio_buffer_data_available(rb)) |
a7348347 JC |
82 | return POLLIN | POLLRDNORM; |
83 | /* need a way of knowing if there may be enough data... */ | |
8d213f24 | 84 | return 0; |
a7348347 JC |
85 | } |
86 | ||
d2f0a48f LPC |
87 | /** |
88 | * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue | |
89 | * @indio_dev: The IIO device | |
90 | * | |
91 | * Wakes up the event waitqueue used for poll(). Should usually | |
92 | * be called when the device is unregistered. | |
93 | */ | |
94 | void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) | |
95 | { | |
96 | if (!indio_dev->buffer) | |
97 | return; | |
98 | ||
99 | wake_up(&indio_dev->buffer->pollq); | |
100 | } | |
101 | ||
f79a9098 | 102 | void iio_buffer_init(struct iio_buffer *buffer) |
7026ea4b | 103 | { |
5ada4ea9 | 104 | INIT_LIST_HEAD(&buffer->demux_list); |
705ee2c9 | 105 | INIT_LIST_HEAD(&buffer->buffer_list); |
14555b14 | 106 | init_waitqueue_head(&buffer->pollq); |
9e69c935 | 107 | kref_init(&buffer->ref); |
7026ea4b | 108 | } |
14555b14 | 109 | EXPORT_SYMBOL(iio_buffer_init); |
7026ea4b | 110 | |
1d892719 | 111 | static ssize_t iio_show_scan_index(struct device *dev, |
8d213f24 JC |
112 | struct device_attribute *attr, |
113 | char *buf) | |
1d892719 | 114 | { |
8d213f24 | 115 | return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index); |
1d892719 JC |
116 | } |
117 | ||
118 | static ssize_t iio_show_fixed_type(struct device *dev, | |
119 | struct device_attribute *attr, | |
120 | char *buf) | |
121 | { | |
122 | struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); | |
8310b86c JC |
123 | u8 type = this_attr->c->scan_type.endianness; |
124 | ||
125 | if (type == IIO_CPU) { | |
9d5d1153 JC |
126 | #ifdef __LITTLE_ENDIAN |
127 | type = IIO_LE; | |
128 | #else | |
129 | type = IIO_BE; | |
130 | #endif | |
8310b86c JC |
131 | } |
132 | return sprintf(buf, "%s:%c%d/%d>>%u\n", | |
133 | iio_endian_prefix[type], | |
1d892719 JC |
134 | this_attr->c->scan_type.sign, |
135 | this_attr->c->scan_type.realbits, | |
136 | this_attr->c->scan_type.storagebits, | |
137 | this_attr->c->scan_type.shift); | |
138 | } | |
139 | ||
8d213f24 JC |
140 | static ssize_t iio_scan_el_show(struct device *dev, |
141 | struct device_attribute *attr, | |
142 | char *buf) | |
143 | { | |
144 | int ret; | |
e53f5ac5 | 145 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
8d213f24 | 146 | |
5ada4ea9 JC |
147 | ret = test_bit(to_iio_dev_attr(attr)->address, |
148 | indio_dev->buffer->scan_mask); | |
149 | ||
8d213f24 JC |
150 | return sprintf(buf, "%d\n", ret); |
151 | } | |
152 | ||
14555b14 | 153 | static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit) |
8d213f24 | 154 | { |
14555b14 | 155 | clear_bit(bit, buffer->scan_mask); |
8d213f24 JC |
156 | return 0; |
157 | } | |
158 | ||
159 | static ssize_t iio_scan_el_store(struct device *dev, | |
160 | struct device_attribute *attr, | |
161 | const char *buf, | |
162 | size_t len) | |
163 | { | |
a714af27 | 164 | int ret; |
8d213f24 | 165 | bool state; |
e53f5ac5 | 166 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
14555b14 | 167 | struct iio_buffer *buffer = indio_dev->buffer; |
8d213f24 JC |
168 | struct iio_dev_attr *this_attr = to_iio_dev_attr(attr); |
169 | ||
a714af27 JC |
170 | ret = strtobool(buf, &state); |
171 | if (ret < 0) | |
172 | return ret; | |
8d213f24 | 173 | mutex_lock(&indio_dev->mlock); |
705ee2c9 | 174 | if (iio_buffer_is_active(indio_dev->buffer)) { |
8d213f24 JC |
175 | ret = -EBUSY; |
176 | goto error_ret; | |
177 | } | |
f79a9098 | 178 | ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address); |
8d213f24 JC |
179 | if (ret < 0) |
180 | goto error_ret; | |
181 | if (!state && ret) { | |
14555b14 | 182 | ret = iio_scan_mask_clear(buffer, this_attr->address); |
8d213f24 JC |
183 | if (ret) |
184 | goto error_ret; | |
185 | } else if (state && !ret) { | |
f79a9098 | 186 | ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address); |
8d213f24 JC |
187 | if (ret) |
188 | goto error_ret; | |
189 | } | |
190 | ||
191 | error_ret: | |
192 | mutex_unlock(&indio_dev->mlock); | |
193 | ||
5a2a6e11 | 194 | return ret < 0 ? ret : len; |
8d213f24 JC |
195 | |
196 | } | |
197 | ||
198 | static ssize_t iio_scan_el_ts_show(struct device *dev, | |
199 | struct device_attribute *attr, | |
200 | char *buf) | |
201 | { | |
e53f5ac5 | 202 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
f8c6f4e9 | 203 | return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp); |
8d213f24 JC |
204 | } |
205 | ||
206 | static ssize_t iio_scan_el_ts_store(struct device *dev, | |
207 | struct device_attribute *attr, | |
208 | const char *buf, | |
209 | size_t len) | |
210 | { | |
a714af27 | 211 | int ret; |
e53f5ac5 | 212 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
8d213f24 | 213 | bool state; |
1aa04278 | 214 | |
a714af27 JC |
215 | ret = strtobool(buf, &state); |
216 | if (ret < 0) | |
217 | return ret; | |
218 | ||
8d213f24 | 219 | mutex_lock(&indio_dev->mlock); |
705ee2c9 | 220 | if (iio_buffer_is_active(indio_dev->buffer)) { |
8d213f24 JC |
221 | ret = -EBUSY; |
222 | goto error_ret; | |
223 | } | |
14555b14 | 224 | indio_dev->buffer->scan_timestamp = state; |
8d213f24 JC |
225 | error_ret: |
226 | mutex_unlock(&indio_dev->mlock); | |
227 | ||
228 | return ret ? ret : len; | |
229 | } | |
230 | ||
14555b14 JC |
231 | static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev, |
232 | const struct iio_chan_spec *chan) | |
1d892719 | 233 | { |
26d25ae3 | 234 | int ret, attrcount = 0; |
14555b14 | 235 | struct iio_buffer *buffer = indio_dev->buffer; |
1d892719 | 236 | |
26d25ae3 | 237 | ret = __iio_add_chan_devattr("index", |
1d892719 JC |
238 | chan, |
239 | &iio_show_scan_index, | |
240 | NULL, | |
241 | 0, | |
3704432f | 242 | IIO_SEPARATE, |
1aa04278 | 243 | &indio_dev->dev, |
14555b14 | 244 | &buffer->scan_el_dev_attr_list); |
1d892719 JC |
245 | if (ret) |
246 | goto error_ret; | |
26d25ae3 JC |
247 | attrcount++; |
248 | ret = __iio_add_chan_devattr("type", | |
1d892719 JC |
249 | chan, |
250 | &iio_show_fixed_type, | |
251 | NULL, | |
252 | 0, | |
253 | 0, | |
1aa04278 | 254 | &indio_dev->dev, |
14555b14 | 255 | &buffer->scan_el_dev_attr_list); |
1d892719 JC |
256 | if (ret) |
257 | goto error_ret; | |
26d25ae3 | 258 | attrcount++; |
a88b3ebc | 259 | if (chan->type != IIO_TIMESTAMP) |
26d25ae3 | 260 | ret = __iio_add_chan_devattr("en", |
a88b3ebc JC |
261 | chan, |
262 | &iio_scan_el_show, | |
263 | &iio_scan_el_store, | |
264 | chan->scan_index, | |
265 | 0, | |
1aa04278 | 266 | &indio_dev->dev, |
14555b14 | 267 | &buffer->scan_el_dev_attr_list); |
a88b3ebc | 268 | else |
26d25ae3 | 269 | ret = __iio_add_chan_devattr("en", |
a88b3ebc JC |
270 | chan, |
271 | &iio_scan_el_ts_show, | |
272 | &iio_scan_el_ts_store, | |
273 | chan->scan_index, | |
274 | 0, | |
1aa04278 | 275 | &indio_dev->dev, |
14555b14 | 276 | &buffer->scan_el_dev_attr_list); |
9572588c PM |
277 | if (ret) |
278 | goto error_ret; | |
26d25ae3 JC |
279 | attrcount++; |
280 | ret = attrcount; | |
1d892719 JC |
281 | error_ret: |
282 | return ret; | |
283 | } | |
284 | ||
26d25ae3 JC |
285 | static const char * const iio_scan_elements_group_name = "scan_elements"; |
286 | ||
14555b14 JC |
287 | int iio_buffer_register(struct iio_dev *indio_dev, |
288 | const struct iio_chan_spec *channels, | |
289 | int num_channels) | |
1d892719 | 290 | { |
26d25ae3 JC |
291 | struct iio_dev_attr *p; |
292 | struct attribute **attr; | |
14555b14 | 293 | struct iio_buffer *buffer = indio_dev->buffer; |
26d25ae3 JC |
294 | int ret, i, attrn, attrcount, attrcount_orig = 0; |
295 | ||
14555b14 JC |
296 | if (buffer->attrs) |
297 | indio_dev->groups[indio_dev->groupcounter++] = buffer->attrs; | |
bf32963c | 298 | |
14555b14 JC |
299 | if (buffer->scan_el_attrs != NULL) { |
300 | attr = buffer->scan_el_attrs->attrs; | |
26d25ae3 JC |
301 | while (*attr++ != NULL) |
302 | attrcount_orig++; | |
303 | } | |
304 | attrcount = attrcount_orig; | |
14555b14 | 305 | INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list); |
1d892719 JC |
306 | if (channels) { |
307 | /* new magic */ | |
308 | for (i = 0; i < num_channels; i++) { | |
f5b81ddd LPC |
309 | if (channels[i].scan_index < 0) |
310 | continue; | |
311 | ||
32b5eeca JC |
312 | /* Establish necessary mask length */ |
313 | if (channels[i].scan_index > | |
314 | (int)indio_dev->masklength - 1) | |
315 | indio_dev->masklength | |
e1dc7bee | 316 | = channels[i].scan_index + 1; |
32b5eeca | 317 | |
14555b14 | 318 | ret = iio_buffer_add_channel_sysfs(indio_dev, |
1aa04278 | 319 | &channels[i]); |
1d892719 | 320 | if (ret < 0) |
26d25ae3 JC |
321 | goto error_cleanup_dynamic; |
322 | attrcount += ret; | |
beb80600 | 323 | if (channels[i].type == IIO_TIMESTAMP) |
f1264809 | 324 | indio_dev->scan_index_timestamp = |
beb80600 | 325 | channels[i].scan_index; |
1d892719 | 326 | } |
14555b14 | 327 | if (indio_dev->masklength && buffer->scan_mask == NULL) { |
d83fb184 TM |
328 | buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength), |
329 | sizeof(*buffer->scan_mask), | |
330 | GFP_KERNEL); | |
14555b14 | 331 | if (buffer->scan_mask == NULL) { |
32b5eeca | 332 | ret = -ENOMEM; |
26d25ae3 | 333 | goto error_cleanup_dynamic; |
32b5eeca JC |
334 | } |
335 | } | |
1d892719 JC |
336 | } |
337 | ||
14555b14 | 338 | buffer->scan_el_group.name = iio_scan_elements_group_name; |
26d25ae3 | 339 | |
d83fb184 TM |
340 | buffer->scan_el_group.attrs = kcalloc(attrcount + 1, |
341 | sizeof(buffer->scan_el_group.attrs[0]), | |
342 | GFP_KERNEL); | |
14555b14 | 343 | if (buffer->scan_el_group.attrs == NULL) { |
26d25ae3 JC |
344 | ret = -ENOMEM; |
345 | goto error_free_scan_mask; | |
346 | } | |
14555b14 JC |
347 | if (buffer->scan_el_attrs) |
348 | memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs, | |
349 | sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig); | |
26d25ae3 JC |
350 | attrn = attrcount_orig; |
351 | ||
14555b14 JC |
352 | list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l) |
353 | buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr; | |
354 | indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group; | |
26d25ae3 | 355 | |
1d892719 | 356 | return 0; |
26d25ae3 JC |
357 | |
358 | error_free_scan_mask: | |
14555b14 | 359 | kfree(buffer->scan_mask); |
1d892719 | 360 | error_cleanup_dynamic: |
84088ebd | 361 | iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); |
26d25ae3 | 362 | |
7026ea4b JC |
363 | return ret; |
364 | } | |
14555b14 | 365 | EXPORT_SYMBOL(iio_buffer_register); |
1d892719 | 366 | |
14555b14 | 367 | void iio_buffer_unregister(struct iio_dev *indio_dev) |
7026ea4b | 368 | { |
14555b14 JC |
369 | kfree(indio_dev->buffer->scan_mask); |
370 | kfree(indio_dev->buffer->scan_el_group.attrs); | |
84088ebd | 371 | iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list); |
7026ea4b | 372 | } |
14555b14 | 373 | EXPORT_SYMBOL(iio_buffer_unregister); |
7026ea4b | 374 | |
14555b14 JC |
375 | ssize_t iio_buffer_read_length(struct device *dev, |
376 | struct device_attribute *attr, | |
377 | char *buf) | |
7026ea4b | 378 | { |
e53f5ac5 | 379 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
14555b14 | 380 | struct iio_buffer *buffer = indio_dev->buffer; |
7026ea4b | 381 | |
14555b14 | 382 | if (buffer->access->get_length) |
8d213f24 | 383 | return sprintf(buf, "%d\n", |
14555b14 | 384 | buffer->access->get_length(buffer)); |
7026ea4b | 385 | |
8d213f24 | 386 | return 0; |
7026ea4b | 387 | } |
14555b14 | 388 | EXPORT_SYMBOL(iio_buffer_read_length); |
7026ea4b | 389 | |
14555b14 JC |
390 | ssize_t iio_buffer_write_length(struct device *dev, |
391 | struct device_attribute *attr, | |
392 | const char *buf, | |
393 | size_t len) | |
7026ea4b | 394 | { |
e53f5ac5 | 395 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
14555b14 | 396 | struct iio_buffer *buffer = indio_dev->buffer; |
948ad205 LPC |
397 | unsigned int val; |
398 | int ret; | |
8d213f24 | 399 | |
948ad205 | 400 | ret = kstrtouint(buf, 10, &val); |
7026ea4b JC |
401 | if (ret) |
402 | return ret; | |
403 | ||
14555b14 JC |
404 | if (buffer->access->get_length) |
405 | if (val == buffer->access->get_length(buffer)) | |
7026ea4b JC |
406 | return len; |
407 | ||
e38c79e0 | 408 | mutex_lock(&indio_dev->mlock); |
705ee2c9 | 409 | if (iio_buffer_is_active(indio_dev->buffer)) { |
e38c79e0 LPC |
410 | ret = -EBUSY; |
411 | } else { | |
869871b5 | 412 | if (buffer->access->set_length) |
e38c79e0 | 413 | buffer->access->set_length(buffer, val); |
e38c79e0 | 414 | ret = 0; |
7026ea4b | 415 | } |
e38c79e0 | 416 | mutex_unlock(&indio_dev->mlock); |
7026ea4b | 417 | |
e38c79e0 | 418 | return ret ? ret : len; |
7026ea4b | 419 | } |
14555b14 | 420 | EXPORT_SYMBOL(iio_buffer_write_length); |
7026ea4b | 421 | |
14555b14 JC |
422 | ssize_t iio_buffer_show_enable(struct device *dev, |
423 | struct device_attribute *attr, | |
424 | char *buf) | |
7026ea4b | 425 | { |
e53f5ac5 | 426 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
705ee2c9 | 427 | return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer)); |
7026ea4b | 428 | } |
14555b14 | 429 | EXPORT_SYMBOL(iio_buffer_show_enable); |
7026ea4b | 430 | |
9572588c | 431 | /* Note NULL used as error indicator as it doesn't make sense. */ |
cd4361c7 | 432 | static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks, |
32b5eeca | 433 | unsigned int masklength, |
cd4361c7 | 434 | const unsigned long *mask) |
32b5eeca JC |
435 | { |
436 | if (bitmap_empty(mask, masklength)) | |
437 | return NULL; | |
438 | while (*av_masks) { | |
439 | if (bitmap_subset(mask, av_masks, masklength)) | |
440 | return av_masks; | |
441 | av_masks += BITS_TO_LONGS(masklength); | |
442 | } | |
443 | return NULL; | |
444 | } | |
445 | ||
183f4173 PM |
446 | static int iio_compute_scan_bytes(struct iio_dev *indio_dev, |
447 | const unsigned long *mask, bool timestamp) | |
959d2952 | 448 | { |
959d2952 JC |
449 | const struct iio_chan_spec *ch; |
450 | unsigned bytes = 0; | |
451 | int length, i; | |
959d2952 JC |
452 | |
453 | /* How much space will the demuxed element take? */ | |
6b3b58ed | 454 | for_each_set_bit(i, mask, |
959d2952 JC |
455 | indio_dev->masklength) { |
456 | ch = iio_find_channel_from_si(indio_dev, i); | |
6b3b58ed | 457 | length = ch->scan_type.storagebits / 8; |
959d2952 JC |
458 | bytes = ALIGN(bytes, length); |
459 | bytes += length; | |
460 | } | |
6b3b58ed | 461 | if (timestamp) { |
959d2952 | 462 | ch = iio_find_channel_from_si(indio_dev, |
f1264809 | 463 | indio_dev->scan_index_timestamp); |
6b3b58ed | 464 | length = ch->scan_type.storagebits / 8; |
959d2952 JC |
465 | bytes = ALIGN(bytes, length); |
466 | bytes += length; | |
467 | } | |
6b3b58ed JC |
468 | return bytes; |
469 | } | |
470 | ||
9e69c935 LPC |
471 | static void iio_buffer_activate(struct iio_dev *indio_dev, |
472 | struct iio_buffer *buffer) | |
473 | { | |
474 | iio_buffer_get(buffer); | |
475 | list_add(&buffer->buffer_list, &indio_dev->buffer_list); | |
476 | } | |
477 | ||
478 | static void iio_buffer_deactivate(struct iio_buffer *buffer) | |
479 | { | |
480 | list_del_init(&buffer->buffer_list); | |
481 | iio_buffer_put(buffer); | |
482 | } | |
483 | ||
a87c82e4 LPC |
484 | void iio_disable_all_buffers(struct iio_dev *indio_dev) |
485 | { | |
486 | struct iio_buffer *buffer, *_buffer; | |
487 | ||
488 | if (list_empty(&indio_dev->buffer_list)) | |
489 | return; | |
490 | ||
491 | if (indio_dev->setup_ops->predisable) | |
492 | indio_dev->setup_ops->predisable(indio_dev); | |
493 | ||
494 | list_for_each_entry_safe(buffer, _buffer, | |
495 | &indio_dev->buffer_list, buffer_list) | |
9e69c935 | 496 | iio_buffer_deactivate(buffer); |
a87c82e4 LPC |
497 | |
498 | indio_dev->currentmode = INDIO_DIRECT_MODE; | |
499 | if (indio_dev->setup_ops->postdisable) | |
500 | indio_dev->setup_ops->postdisable(indio_dev); | |
e086ed76 LPC |
501 | |
502 | if (indio_dev->available_scan_masks == NULL) | |
503 | kfree(indio_dev->active_scan_mask); | |
a87c82e4 LPC |
504 | } |
505 | ||
8e050996 LPC |
506 | static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev, |
507 | struct iio_buffer *buffer) | |
508 | { | |
509 | unsigned int bytes; | |
510 | ||
511 | if (!buffer->access->set_bytes_per_datum) | |
512 | return; | |
513 | ||
514 | bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask, | |
515 | buffer->scan_timestamp); | |
516 | ||
517 | buffer->access->set_bytes_per_datum(buffer, bytes); | |
518 | } | |
519 | ||
a9519456 | 520 | static int __iio_update_buffers(struct iio_dev *indio_dev, |
84b36ce5 JC |
521 | struct iio_buffer *insert_buffer, |
522 | struct iio_buffer *remove_buffer) | |
6b3b58ed | 523 | { |
84b36ce5 JC |
524 | int ret; |
525 | int success = 0; | |
526 | struct iio_buffer *buffer; | |
527 | unsigned long *compound_mask; | |
528 | const unsigned long *old_mask; | |
6b3b58ed | 529 | |
84b36ce5 JC |
530 | /* Wind down existing buffers - iff there are any */ |
531 | if (!list_empty(&indio_dev->buffer_list)) { | |
532 | if (indio_dev->setup_ops->predisable) { | |
533 | ret = indio_dev->setup_ops->predisable(indio_dev); | |
534 | if (ret) | |
535 | goto error_ret; | |
536 | } | |
537 | indio_dev->currentmode = INDIO_DIRECT_MODE; | |
538 | if (indio_dev->setup_ops->postdisable) { | |
539 | ret = indio_dev->setup_ops->postdisable(indio_dev); | |
540 | if (ret) | |
541 | goto error_ret; | |
542 | } | |
543 | } | |
544 | /* Keep a copy of current setup to allow roll back */ | |
545 | old_mask = indio_dev->active_scan_mask; | |
546 | if (!indio_dev->available_scan_masks) | |
547 | indio_dev->active_scan_mask = NULL; | |
548 | ||
549 | if (remove_buffer) | |
9e69c935 | 550 | iio_buffer_deactivate(remove_buffer); |
84b36ce5 | 551 | if (insert_buffer) |
9e69c935 | 552 | iio_buffer_activate(indio_dev, insert_buffer); |
84b36ce5 JC |
553 | |
554 | /* If no buffers in list, we are done */ | |
555 | if (list_empty(&indio_dev->buffer_list)) { | |
556 | indio_dev->currentmode = INDIO_DIRECT_MODE; | |
557 | if (indio_dev->available_scan_masks == NULL) | |
558 | kfree(old_mask); | |
559 | return 0; | |
560 | } | |
959d2952 | 561 | |
9572588c | 562 | /* What scan mask do we actually have? */ |
84b36ce5 JC |
563 | compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength), |
564 | sizeof(long), GFP_KERNEL); | |
565 | if (compound_mask == NULL) { | |
566 | if (indio_dev->available_scan_masks == NULL) | |
567 | kfree(old_mask); | |
568 | return -ENOMEM; | |
569 | } | |
570 | indio_dev->scan_timestamp = 0; | |
571 | ||
572 | list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { | |
573 | bitmap_or(compound_mask, compound_mask, buffer->scan_mask, | |
574 | indio_dev->masklength); | |
575 | indio_dev->scan_timestamp |= buffer->scan_timestamp; | |
576 | } | |
577 | if (indio_dev->available_scan_masks) { | |
959d2952 JC |
578 | indio_dev->active_scan_mask = |
579 | iio_scan_mask_match(indio_dev->available_scan_masks, | |
580 | indio_dev->masklength, | |
84b36ce5 JC |
581 | compound_mask); |
582 | if (indio_dev->active_scan_mask == NULL) { | |
583 | /* | |
584 | * Roll back. | |
585 | * Note can only occur when adding a buffer. | |
586 | */ | |
9e69c935 | 587 | iio_buffer_deactivate(insert_buffer); |
d66e0452 PM |
588 | if (old_mask) { |
589 | indio_dev->active_scan_mask = old_mask; | |
590 | success = -EINVAL; | |
591 | } | |
592 | else { | |
593 | kfree(compound_mask); | |
594 | ret = -EINVAL; | |
595 | goto error_ret; | |
596 | } | |
84b36ce5 JC |
597 | } |
598 | } else { | |
599 | indio_dev->active_scan_mask = compound_mask; | |
600 | } | |
aff1eb4e | 601 | |
5ada4ea9 JC |
602 | iio_update_demux(indio_dev); |
603 | ||
84b36ce5 JC |
604 | /* Wind up again */ |
605 | if (indio_dev->setup_ops->preenable) { | |
606 | ret = indio_dev->setup_ops->preenable(indio_dev); | |
607 | if (ret) { | |
608 | printk(KERN_ERR | |
bec1889d | 609 | "Buffer not started: buffer preenable failed (%d)\n", ret); |
84b36ce5 JC |
610 | goto error_remove_inserted; |
611 | } | |
612 | } | |
613 | indio_dev->scan_bytes = | |
614 | iio_compute_scan_bytes(indio_dev, | |
615 | indio_dev->active_scan_mask, | |
616 | indio_dev->scan_timestamp); | |
8e050996 LPC |
617 | list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { |
618 | iio_buffer_update_bytes_per_datum(indio_dev, buffer); | |
84b36ce5 JC |
619 | if (buffer->access->request_update) { |
620 | ret = buffer->access->request_update(buffer); | |
621 | if (ret) { | |
622 | printk(KERN_INFO | |
bec1889d | 623 | "Buffer not started: buffer parameter update failed (%d)\n", ret); |
84b36ce5 JC |
624 | goto error_run_postdisable; |
625 | } | |
626 | } | |
8e050996 | 627 | } |
84b36ce5 JC |
628 | if (indio_dev->info->update_scan_mode) { |
629 | ret = indio_dev->info | |
5ada4ea9 JC |
630 | ->update_scan_mode(indio_dev, |
631 | indio_dev->active_scan_mask); | |
84b36ce5 | 632 | if (ret < 0) { |
bec1889d | 633 | printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret); |
84b36ce5 JC |
634 | goto error_run_postdisable; |
635 | } | |
636 | } | |
9572588c | 637 | /* Definitely possible for devices to support both of these. */ |
84b36ce5 JC |
638 | if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) { |
639 | if (!indio_dev->trig) { | |
640 | printk(KERN_INFO "Buffer not started: no trigger\n"); | |
641 | ret = -EINVAL; | |
642 | /* Can only occur on first buffer */ | |
643 | goto error_run_postdisable; | |
644 | } | |
645 | indio_dev->currentmode = INDIO_BUFFER_TRIGGERED; | |
646 | } else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) { | |
647 | indio_dev->currentmode = INDIO_BUFFER_HARDWARE; | |
9572588c | 648 | } else { /* Should never be reached */ |
84b36ce5 JC |
649 | ret = -EINVAL; |
650 | goto error_run_postdisable; | |
651 | } | |
652 | ||
653 | if (indio_dev->setup_ops->postenable) { | |
654 | ret = indio_dev->setup_ops->postenable(indio_dev); | |
655 | if (ret) { | |
656 | printk(KERN_INFO | |
bec1889d | 657 | "Buffer not started: postenable failed (%d)\n", ret); |
84b36ce5 JC |
658 | indio_dev->currentmode = INDIO_DIRECT_MODE; |
659 | if (indio_dev->setup_ops->postdisable) | |
660 | indio_dev->setup_ops->postdisable(indio_dev); | |
661 | goto error_disable_all_buffers; | |
662 | } | |
663 | } | |
664 | ||
665 | if (indio_dev->available_scan_masks) | |
666 | kfree(compound_mask); | |
667 | else | |
668 | kfree(old_mask); | |
669 | ||
670 | return success; | |
671 | ||
672 | error_disable_all_buffers: | |
673 | indio_dev->currentmode = INDIO_DIRECT_MODE; | |
674 | error_run_postdisable: | |
675 | if (indio_dev->setup_ops->postdisable) | |
676 | indio_dev->setup_ops->postdisable(indio_dev); | |
677 | error_remove_inserted: | |
678 | ||
679 | if (insert_buffer) | |
9e69c935 | 680 | iio_buffer_deactivate(insert_buffer); |
84b36ce5 JC |
681 | indio_dev->active_scan_mask = old_mask; |
682 | kfree(compound_mask); | |
683 | error_ret: | |
684 | ||
685 | return ret; | |
686 | } | |
a9519456 LPC |
687 | |
688 | int iio_update_buffers(struct iio_dev *indio_dev, | |
689 | struct iio_buffer *insert_buffer, | |
690 | struct iio_buffer *remove_buffer) | |
691 | { | |
692 | int ret; | |
693 | ||
3909fab5 LPC |
694 | if (insert_buffer == remove_buffer) |
695 | return 0; | |
696 | ||
a9519456 LPC |
697 | mutex_lock(&indio_dev->info_exist_lock); |
698 | mutex_lock(&indio_dev->mlock); | |
699 | ||
3909fab5 LPC |
700 | if (insert_buffer && iio_buffer_is_active(insert_buffer)) |
701 | insert_buffer = NULL; | |
702 | ||
703 | if (remove_buffer && !iio_buffer_is_active(remove_buffer)) | |
704 | remove_buffer = NULL; | |
705 | ||
706 | if (!insert_buffer && !remove_buffer) { | |
707 | ret = 0; | |
708 | goto out_unlock; | |
709 | } | |
710 | ||
a9519456 LPC |
711 | if (indio_dev->info == NULL) { |
712 | ret = -ENODEV; | |
713 | goto out_unlock; | |
714 | } | |
715 | ||
716 | ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer); | |
717 | ||
718 | out_unlock: | |
719 | mutex_unlock(&indio_dev->mlock); | |
720 | mutex_unlock(&indio_dev->info_exist_lock); | |
721 | ||
722 | return ret; | |
723 | } | |
84b36ce5 JC |
724 | EXPORT_SYMBOL_GPL(iio_update_buffers); |
725 | ||
726 | ssize_t iio_buffer_store_enable(struct device *dev, | |
727 | struct device_attribute *attr, | |
728 | const char *buf, | |
729 | size_t len) | |
730 | { | |
731 | int ret; | |
732 | bool requested_state; | |
733 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); | |
84b36ce5 JC |
734 | bool inlist; |
735 | ||
736 | ret = strtobool(buf, &requested_state); | |
737 | if (ret < 0) | |
738 | return ret; | |
739 | ||
740 | mutex_lock(&indio_dev->mlock); | |
741 | ||
742 | /* Find out if it is in the list */ | |
705ee2c9 | 743 | inlist = iio_buffer_is_active(indio_dev->buffer); |
84b36ce5 JC |
744 | /* Already in desired state */ |
745 | if (inlist == requested_state) | |
746 | goto done; | |
747 | ||
748 | if (requested_state) | |
a9519456 | 749 | ret = __iio_update_buffers(indio_dev, |
84b36ce5 JC |
750 | indio_dev->buffer, NULL); |
751 | else | |
a9519456 | 752 | ret = __iio_update_buffers(indio_dev, |
84b36ce5 JC |
753 | NULL, indio_dev->buffer); |
754 | ||
755 | if (ret < 0) | |
756 | goto done; | |
757 | done: | |
758 | mutex_unlock(&indio_dev->mlock); | |
759 | return (ret < 0) ? ret : len; | |
760 | } | |
761 | EXPORT_SYMBOL(iio_buffer_store_enable); | |
762 | ||
81636632 LPC |
763 | /** |
764 | * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected | |
765 | * @indio_dev: the iio device | |
766 | * @mask: scan mask to be checked | |
767 | * | |
768 | * Return true if exactly one bit is set in the scan mask, false otherwise. It | |
769 | * can be used for devices where only one channel can be active for sampling at | |
770 | * a time. | |
771 | */ | |
772 | bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, | |
773 | const unsigned long *mask) | |
774 | { | |
775 | return bitmap_weight(mask, indio_dev->masklength) == 1; | |
776 | } | |
777 | EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot); | |
778 | ||
939546d1 LPC |
779 | static bool iio_validate_scan_mask(struct iio_dev *indio_dev, |
780 | const unsigned long *mask) | |
781 | { | |
782 | if (!indio_dev->setup_ops->validate_scan_mask) | |
783 | return true; | |
784 | ||
785 | return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask); | |
786 | } | |
787 | ||
32b5eeca JC |
788 | /** |
789 | * iio_scan_mask_set() - set particular bit in the scan mask | |
9572588c | 790 | * @indio_dev: the iio device |
14555b14 | 791 | * @buffer: the buffer whose scan mask we are interested in |
32b5eeca | 792 | * @bit: the bit to be set. |
84b36ce5 JC |
793 | * |
794 | * Note that at this point we have no way of knowing what other | |
795 | * buffers might request, hence this code only verifies that the | |
796 | * individual buffers request is plausible. | |
797 | */ | |
f79a9098 JC |
798 | int iio_scan_mask_set(struct iio_dev *indio_dev, |
799 | struct iio_buffer *buffer, int bit) | |
32b5eeca | 800 | { |
cd4361c7 | 801 | const unsigned long *mask; |
32b5eeca JC |
802 | unsigned long *trialmask; |
803 | ||
804 | trialmask = kmalloc(sizeof(*trialmask)* | |
f8c6f4e9 | 805 | BITS_TO_LONGS(indio_dev->masklength), |
32b5eeca JC |
806 | GFP_KERNEL); |
807 | ||
808 | if (trialmask == NULL) | |
809 | return -ENOMEM; | |
f8c6f4e9 | 810 | if (!indio_dev->masklength) { |
9572588c | 811 | WARN_ON("Trying to set scanmask prior to registering buffer\n"); |
939546d1 | 812 | goto err_invalid_mask; |
32b5eeca | 813 | } |
f8c6f4e9 | 814 | bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength); |
32b5eeca JC |
815 | set_bit(bit, trialmask); |
816 | ||
939546d1 LPC |
817 | if (!iio_validate_scan_mask(indio_dev, trialmask)) |
818 | goto err_invalid_mask; | |
819 | ||
f8c6f4e9 JC |
820 | if (indio_dev->available_scan_masks) { |
821 | mask = iio_scan_mask_match(indio_dev->available_scan_masks, | |
822 | indio_dev->masklength, | |
32b5eeca | 823 | trialmask); |
939546d1 LPC |
824 | if (!mask) |
825 | goto err_invalid_mask; | |
32b5eeca | 826 | } |
f8c6f4e9 | 827 | bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength); |
32b5eeca JC |
828 | |
829 | kfree(trialmask); | |
830 | ||
831 | return 0; | |
939546d1 LPC |
832 | |
833 | err_invalid_mask: | |
834 | kfree(trialmask); | |
835 | return -EINVAL; | |
836 | } | |
32b5eeca JC |
837 | EXPORT_SYMBOL_GPL(iio_scan_mask_set); |
838 | ||
f79a9098 JC |
839 | int iio_scan_mask_query(struct iio_dev *indio_dev, |
840 | struct iio_buffer *buffer, int bit) | |
32b5eeca | 841 | { |
f8c6f4e9 | 842 | if (bit > indio_dev->masklength) |
32b5eeca JC |
843 | return -EINVAL; |
844 | ||
14555b14 | 845 | if (!buffer->scan_mask) |
32b5eeca | 846 | return 0; |
32b5eeca | 847 | |
5a2a6e11 | 848 | return test_bit(bit, buffer->scan_mask); |
32b5eeca JC |
849 | }; |
850 | EXPORT_SYMBOL_GPL(iio_scan_mask_query); | |
5ada4ea9 JC |
851 | |
852 | /** | |
853 | * struct iio_demux_table() - table describing demux memcpy ops | |
854 | * @from: index to copy from | |
99698b45 | 855 | * @to: index to copy to |
5ada4ea9 JC |
856 | * @length: how many bytes to copy |
857 | * @l: list head used for management | |
858 | */ | |
859 | struct iio_demux_table { | |
860 | unsigned from; | |
861 | unsigned to; | |
862 | unsigned length; | |
863 | struct list_head l; | |
864 | }; | |
865 | ||
5d65d920 LPC |
866 | static const void *iio_demux(struct iio_buffer *buffer, |
867 | const void *datain) | |
5ada4ea9 JC |
868 | { |
869 | struct iio_demux_table *t; | |
870 | ||
871 | if (list_empty(&buffer->demux_list)) | |
872 | return datain; | |
873 | list_for_each_entry(t, &buffer->demux_list, l) | |
874 | memcpy(buffer->demux_bounce + t->to, | |
875 | datain + t->from, t->length); | |
876 | ||
877 | return buffer->demux_bounce; | |
878 | } | |
879 | ||
5d65d920 | 880 | static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data) |
5ada4ea9 | 881 | { |
5d65d920 | 882 | const void *dataout = iio_demux(buffer, data); |
5ada4ea9 | 883 | |
ce56ade6 | 884 | return buffer->access->store_to(buffer, dataout); |
5ada4ea9 | 885 | } |
5ada4ea9 | 886 | |
842cd100 JC |
887 | static void iio_buffer_demux_free(struct iio_buffer *buffer) |
888 | { | |
889 | struct iio_demux_table *p, *q; | |
890 | list_for_each_entry_safe(p, q, &buffer->demux_list, l) { | |
891 | list_del(&p->l); | |
892 | kfree(p); | |
893 | } | |
894 | } | |
895 | ||
84b36ce5 | 896 | |
5d65d920 | 897 | int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data) |
84b36ce5 JC |
898 | { |
899 | int ret; | |
900 | struct iio_buffer *buf; | |
901 | ||
902 | list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) { | |
903 | ret = iio_push_to_buffer(buf, data); | |
904 | if (ret < 0) | |
905 | return ret; | |
906 | } | |
907 | ||
908 | return 0; | |
909 | } | |
910 | EXPORT_SYMBOL_GPL(iio_push_to_buffers); | |
911 | ||
912 | static int iio_buffer_update_demux(struct iio_dev *indio_dev, | |
913 | struct iio_buffer *buffer) | |
5ada4ea9 JC |
914 | { |
915 | const struct iio_chan_spec *ch; | |
5ada4ea9 JC |
916 | int ret, in_ind = -1, out_ind, length; |
917 | unsigned in_loc = 0, out_loc = 0; | |
842cd100 | 918 | struct iio_demux_table *p; |
5ada4ea9 JC |
919 | |
920 | /* Clear out any old demux */ | |
842cd100 | 921 | iio_buffer_demux_free(buffer); |
5ada4ea9 JC |
922 | kfree(buffer->demux_bounce); |
923 | buffer->demux_bounce = NULL; | |
924 | ||
925 | /* First work out which scan mode we will actually have */ | |
926 | if (bitmap_equal(indio_dev->active_scan_mask, | |
927 | buffer->scan_mask, | |
928 | indio_dev->masklength)) | |
929 | return 0; | |
930 | ||
931 | /* Now we have the two masks, work from least sig and build up sizes */ | |
932 | for_each_set_bit(out_ind, | |
933 | indio_dev->active_scan_mask, | |
934 | indio_dev->masklength) { | |
935 | in_ind = find_next_bit(indio_dev->active_scan_mask, | |
936 | indio_dev->masklength, | |
937 | in_ind + 1); | |
938 | while (in_ind != out_ind) { | |
939 | in_ind = find_next_bit(indio_dev->active_scan_mask, | |
940 | indio_dev->masklength, | |
941 | in_ind + 1); | |
942 | ch = iio_find_channel_from_si(indio_dev, in_ind); | |
943 | length = ch->scan_type.storagebits/8; | |
944 | /* Make sure we are aligned */ | |
945 | in_loc += length; | |
946 | if (in_loc % length) | |
947 | in_loc += length - in_loc % length; | |
948 | } | |
949 | p = kmalloc(sizeof(*p), GFP_KERNEL); | |
950 | if (p == NULL) { | |
951 | ret = -ENOMEM; | |
952 | goto error_clear_mux_table; | |
953 | } | |
954 | ch = iio_find_channel_from_si(indio_dev, in_ind); | |
955 | length = ch->scan_type.storagebits/8; | |
956 | if (out_loc % length) | |
957 | out_loc += length - out_loc % length; | |
958 | if (in_loc % length) | |
959 | in_loc += length - in_loc % length; | |
960 | p->from = in_loc; | |
961 | p->to = out_loc; | |
962 | p->length = length; | |
963 | list_add_tail(&p->l, &buffer->demux_list); | |
964 | out_loc += length; | |
965 | in_loc += length; | |
966 | } | |
967 | /* Relies on scan_timestamp being last */ | |
968 | if (buffer->scan_timestamp) { | |
969 | p = kmalloc(sizeof(*p), GFP_KERNEL); | |
970 | if (p == NULL) { | |
971 | ret = -ENOMEM; | |
972 | goto error_clear_mux_table; | |
973 | } | |
974 | ch = iio_find_channel_from_si(indio_dev, | |
f1264809 | 975 | indio_dev->scan_index_timestamp); |
5ada4ea9 JC |
976 | length = ch->scan_type.storagebits/8; |
977 | if (out_loc % length) | |
978 | out_loc += length - out_loc % length; | |
979 | if (in_loc % length) | |
980 | in_loc += length - in_loc % length; | |
981 | p->from = in_loc; | |
982 | p->to = out_loc; | |
983 | p->length = length; | |
984 | list_add_tail(&p->l, &buffer->demux_list); | |
985 | out_loc += length; | |
986 | in_loc += length; | |
987 | } | |
988 | buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL); | |
989 | if (buffer->demux_bounce == NULL) { | |
990 | ret = -ENOMEM; | |
991 | goto error_clear_mux_table; | |
992 | } | |
993 | return 0; | |
994 | ||
995 | error_clear_mux_table: | |
842cd100 JC |
996 | iio_buffer_demux_free(buffer); |
997 | ||
5ada4ea9 JC |
998 | return ret; |
999 | } | |
84b36ce5 JC |
1000 | |
1001 | int iio_update_demux(struct iio_dev *indio_dev) | |
1002 | { | |
1003 | struct iio_buffer *buffer; | |
1004 | int ret; | |
1005 | ||
1006 | list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) { | |
1007 | ret = iio_buffer_update_demux(indio_dev, buffer); | |
1008 | if (ret < 0) | |
1009 | goto error_clear_mux_table; | |
1010 | } | |
1011 | return 0; | |
1012 | ||
1013 | error_clear_mux_table: | |
1014 | list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) | |
1015 | iio_buffer_demux_free(buffer); | |
1016 | ||
1017 | return ret; | |
1018 | } | |
5ada4ea9 | 1019 | EXPORT_SYMBOL_GPL(iio_update_demux); |
9e69c935 LPC |
1020 | |
1021 | /** | |
1022 | * iio_buffer_release() - Free a buffer's resources | |
1023 | * @ref: Pointer to the kref embedded in the iio_buffer struct | |
1024 | * | |
1025 | * This function is called when the last reference to the buffer has been | |
1026 | * dropped. It will typically free all resources allocated by the buffer. Do not | |
1027 | * call this function manually, always use iio_buffer_put() when done using a | |
1028 | * buffer. | |
1029 | */ | |
1030 | static void iio_buffer_release(struct kref *ref) | |
1031 | { | |
1032 | struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref); | |
1033 | ||
1034 | buffer->access->release(buffer); | |
1035 | } | |
1036 | ||
1037 | /** | |
1038 | * iio_buffer_get() - Grab a reference to the buffer | |
1039 | * @buffer: The buffer to grab a reference for, may be NULL | |
1040 | * | |
1041 | * Returns the pointer to the buffer that was passed into the function. | |
1042 | */ | |
1043 | struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer) | |
1044 | { | |
1045 | if (buffer) | |
1046 | kref_get(&buffer->ref); | |
1047 | ||
1048 | return buffer; | |
1049 | } | |
1050 | EXPORT_SYMBOL_GPL(iio_buffer_get); | |
1051 | ||
1052 | /** | |
1053 | * iio_buffer_put() - Release the reference to the buffer | |
1054 | * @buffer: The buffer to release the reference for, may be NULL | |
1055 | */ | |
1056 | void iio_buffer_put(struct iio_buffer *buffer) | |
1057 | { | |
1058 | if (buffer) | |
1059 | kref_put(&buffer->ref, iio_buffer_release); | |
1060 | } | |
1061 | EXPORT_SYMBOL_GPL(iio_buffer_put); |