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Jonathan Cameron14555b12011-09-21 11:15:57 +01001/* 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 *
9 * Handling of buffer allocation / resizing.
10 *
11 *
12 * Things to look at here.
13 * - Better memory allocation techniques?
14 * - Alternative access techniques?
15 */
16#include <linux/kernel.h>
Paul Gortmaker8e336a72011-07-10 13:09:12 -040017#include <linux/export.h>
Jonathan Cameron14555b12011-09-21 11:15:57 +010018#include <linux/device.h>
19#include <linux/fs.h>
20#include <linux/cdev.h>
21#include <linux/slab.h>
22#include <linux/poll.h>
Lars-Peter Clausend2f0a482013-10-04 12:07:00 +010023#include <linux/sched.h>
Jonathan Cameron14555b12011-09-21 11:15:57 +010024
Jonathan Cameron06458e22012-04-25 15:54:58 +010025#include <linux/iio/iio.h>
Jonathan Cameron14555b12011-09-21 11:15:57 +010026#include "iio_core.h"
Jonathan Cameron06458e22012-04-25 15:54:58 +010027#include <linux/iio/sysfs.h>
28#include <linux/iio/buffer.h>
Jonathan Cameron14555b12011-09-21 11:15:57 +010029
30static const char * const iio_endian_prefix[] = {
31 [IIO_BE] = "be",
32 [IIO_LE] = "le",
33};
34
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +010035static bool iio_buffer_is_active(struct iio_buffer *buf)
Jonathan Cameron84b36ce2012-06-30 20:06:00 +010036{
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +010037 return !list_empty(&buf->buffer_list);
Jonathan Cameron84b36ce2012-06-30 20:06:00 +010038}
39
Josselin Costanzi37d34552015-03-22 20:33:38 +020040static size_t iio_buffer_data_available(struct iio_buffer *buf)
Lars-Peter Clausen647cc7b2013-11-25 14:56:00 +000041{
Josselin Costanzi9dd46942014-06-27 17:20:00 +010042 return buf->access->data_available(buf);
Lars-Peter Clausen647cc7b2013-11-25 14:56:00 +000043}
44
Octavian Purdilaf4f46732015-03-22 20:33:39 +020045static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
46 struct iio_buffer *buf, size_t required)
Josselin Costanzi37d34552015-03-22 20:33:38 +020047{
Octavian Purdilaf4f46732015-03-22 20:33:39 +020048 if (!indio_dev->info->hwfifo_flush_to_buffer)
49 return -ENODEV;
50
51 return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
52}
53
54static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
55 size_t to_wait, int to_flush)
56{
57 size_t avail;
58 int flushed = 0;
59
Josselin Costanzi37d34552015-03-22 20:33:38 +020060 /* wakeup if the device was unregistered */
61 if (!indio_dev->info)
62 return true;
63
64 /* drain the buffer if it was disabled */
Octavian Purdilaf4f46732015-03-22 20:33:39 +020065 if (!iio_buffer_is_active(buf)) {
Josselin Costanzi37d34552015-03-22 20:33:38 +020066 to_wait = min_t(size_t, to_wait, 1);
Octavian Purdilaf4f46732015-03-22 20:33:39 +020067 to_flush = 0;
68 }
Josselin Costanzi37d34552015-03-22 20:33:38 +020069
Octavian Purdilaf4f46732015-03-22 20:33:39 +020070 avail = iio_buffer_data_available(buf);
71
72 if (avail >= to_wait) {
73 /* force a flush for non-blocking reads */
Octavian Purdilac6f67a12015-06-05 15:56:47 +030074 if (!to_wait && avail < to_flush)
75 iio_buffer_flush_hwfifo(indio_dev, buf,
76 to_flush - avail);
Octavian Purdilaf4f46732015-03-22 20:33:39 +020077 return true;
78 }
79
80 if (to_flush)
81 flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
82 to_wait - avail);
83 if (flushed <= 0)
84 return false;
85
86 if (avail + flushed >= to_wait)
Josselin Costanzi37d34552015-03-22 20:33:38 +020087 return true;
88
89 return false;
90}
91
Jonathan Cameron14555b12011-09-21 11:15:57 +010092/**
93 * iio_buffer_read_first_n_outer() - chrdev read for buffer access
Cristina Opriceana01236352015-07-24 16:18:09 +030094 * @filp: File structure pointer for the char device
95 * @buf: Destination buffer for iio buffer read
96 * @n: First n bytes to read
97 * @f_ps: Long offset provided by the user as a seek position
Jonathan Cameron14555b12011-09-21 11:15:57 +010098 *
99 * This function relies on all buffer implementations having an
100 * iio_buffer as their first element.
Cristina Opriceana01236352015-07-24 16:18:09 +0300101 *
102 * Return: negative values corresponding to error codes or ret != 0
103 * for ending the reading activity
Jonathan Cameron14555b12011-09-21 11:15:57 +0100104 **/
105ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
106 size_t n, loff_t *f_ps)
107{
108 struct iio_dev *indio_dev = filp->private_data;
109 struct iio_buffer *rb = indio_dev->buffer;
Josselin Costanzi37d34552015-03-22 20:33:38 +0200110 size_t datum_size;
Octavian Purdilac6f67a12015-06-05 15:56:47 +0300111 size_t to_wait;
Lars-Peter Clausenee551a12013-11-25 14:56:00 +0000112 int ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100113
Lars-Peter Clausenf18e7a02013-10-04 12:06:00 +0100114 if (!indio_dev->info)
115 return -ENODEV;
116
Jonathan Cameron96e00f12011-10-26 17:27:45 +0100117 if (!rb || !rb->access->read_first_n)
Jonathan Cameron14555b12011-09-21 11:15:57 +0100118 return -EINVAL;
Lars-Peter Clausenee551a12013-11-25 14:56:00 +0000119
Josselin Costanzi37d34552015-03-22 20:33:38 +0200120 datum_size = rb->bytes_per_datum;
Lars-Peter Clausenee551a12013-11-25 14:56:00 +0000121
Josselin Costanzi37d34552015-03-22 20:33:38 +0200122 /*
123 * If datum_size is 0 there will never be anything to read from the
124 * buffer, so signal end of file now.
125 */
126 if (!datum_size)
127 return 0;
128
Octavian Purdilac6f67a12015-06-05 15:56:47 +0300129 if (filp->f_flags & O_NONBLOCK)
130 to_wait = 0;
131 else
132 to_wait = min_t(size_t, n / datum_size, rb->watermark);
Josselin Costanzi37d34552015-03-22 20:33:38 +0200133
134 do {
135 ret = wait_event_interruptible(rb->pollq,
Octavian Purdilac6f67a12015-06-05 15:56:47 +0300136 iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size));
Josselin Costanzi37d34552015-03-22 20:33:38 +0200137 if (ret)
138 return ret;
139
140 if (!indio_dev->info)
141 return -ENODEV;
Lars-Peter Clausenee551a12013-11-25 14:56:00 +0000142
143 ret = rb->access->read_first_n(rb, n, buf);
144 if (ret == 0 && (filp->f_flags & O_NONBLOCK))
145 ret = -EAGAIN;
146 } while (ret == 0);
147
148 return ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100149}
150
151/**
152 * iio_buffer_poll() - poll the buffer to find out if it has data
Cristina Opriceana01236352015-07-24 16:18:09 +0300153 * @filp: File structure pointer for device access
154 * @wait: Poll table structure pointer for which the driver adds
155 * a wait queue
156 *
157 * Return: (POLLIN | POLLRDNORM) if data is available for reading
158 * or 0 for other cases
Jonathan Cameron14555b12011-09-21 11:15:57 +0100159 */
160unsigned int iio_buffer_poll(struct file *filp,
161 struct poll_table_struct *wait)
162{
163 struct iio_dev *indio_dev = filp->private_data;
164 struct iio_buffer *rb = indio_dev->buffer;
165
Lars-Peter Clausenf18e7a02013-10-04 12:06:00 +0100166 if (!indio_dev->info)
Cristina Opriceana1bdc0292015-08-03 13:37:40 +0300167 return 0;
Lars-Peter Clausenf18e7a02013-10-04 12:06:00 +0100168
Jonathan Cameron14555b12011-09-21 11:15:57 +0100169 poll_wait(filp, &rb->pollq, wait);
Octavian Purdilaf4f46732015-03-22 20:33:39 +0200170 if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
Jonathan Cameron14555b12011-09-21 11:15:57 +0100171 return POLLIN | POLLRDNORM;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100172 return 0;
173}
174
Lars-Peter Clausend2f0a482013-10-04 12:07:00 +0100175/**
176 * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
177 * @indio_dev: The IIO device
178 *
179 * Wakes up the event waitqueue used for poll(). Should usually
180 * be called when the device is unregistered.
181 */
182void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
183{
184 if (!indio_dev->buffer)
185 return;
186
187 wake_up(&indio_dev->buffer->pollq);
188}
189
Jonathan Cameronf79a9092011-12-05 22:18:29 +0000190void iio_buffer_init(struct iio_buffer *buffer)
Jonathan Cameron14555b12011-09-21 11:15:57 +0100191{
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +0000192 INIT_LIST_HEAD(&buffer->demux_list);
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +0100193 INIT_LIST_HEAD(&buffer->buffer_list);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100194 init_waitqueue_head(&buffer->pollq);
Lars-Peter Clausen9e69c932013-10-04 12:06:00 +0100195 kref_init(&buffer->ref);
Lars-Peter Clausen4a605352015-10-13 18:10:25 +0200196 if (!buffer->watermark)
197 buffer->watermark = 1;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100198}
199EXPORT_SYMBOL(iio_buffer_init);
200
201static ssize_t iio_show_scan_index(struct device *dev,
202 struct device_attribute *attr,
203 char *buf)
204{
205 return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
206}
207
208static ssize_t iio_show_fixed_type(struct device *dev,
209 struct device_attribute *attr,
210 char *buf)
211{
212 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
213 u8 type = this_attr->c->scan_type.endianness;
214
215 if (type == IIO_CPU) {
Jonathan Cameron9d5d1152011-10-04 16:02:08 +0100216#ifdef __LITTLE_ENDIAN
217 type = IIO_LE;
218#else
219 type = IIO_BE;
220#endif
Jonathan Cameron14555b12011-09-21 11:15:57 +0100221 }
Srinivas Pandruvada0ee85462014-04-29 00:51:00 +0100222 if (this_attr->c->scan_type.repeat > 1)
223 return sprintf(buf, "%s:%c%d/%dX%d>>%u\n",
224 iio_endian_prefix[type],
225 this_attr->c->scan_type.sign,
226 this_attr->c->scan_type.realbits,
227 this_attr->c->scan_type.storagebits,
228 this_attr->c->scan_type.repeat,
229 this_attr->c->scan_type.shift);
230 else
231 return sprintf(buf, "%s:%c%d/%d>>%u\n",
Jonathan Cameron14555b12011-09-21 11:15:57 +0100232 iio_endian_prefix[type],
233 this_attr->c->scan_type.sign,
234 this_attr->c->scan_type.realbits,
235 this_attr->c->scan_type.storagebits,
236 this_attr->c->scan_type.shift);
237}
238
239static ssize_t iio_scan_el_show(struct device *dev,
240 struct device_attribute *attr,
241 char *buf)
242{
243 int ret;
Lars-Peter Clausene53f5ac2012-05-12 15:39:33 +0200244 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100245
Alec Berg2076a202014-03-19 18:50:00 +0000246 /* Ensure ret is 0 or 1. */
247 ret = !!test_bit(to_iio_dev_attr(attr)->address,
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +0000248 indio_dev->buffer->scan_mask);
249
Jonathan Cameron14555b12011-09-21 11:15:57 +0100250 return sprintf(buf, "%d\n", ret);
251}
252
Lars-Peter Clausen217a5cf2014-11-26 18:55:09 +0100253/* Note NULL used as error indicator as it doesn't make sense. */
254static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
255 unsigned int masklength,
Lars-Peter Clausen1e1ec282015-05-29 18:14:22 +0200256 const unsigned long *mask,
257 bool strict)
Lars-Peter Clausen217a5cf2014-11-26 18:55:09 +0100258{
259 if (bitmap_empty(mask, masklength))
260 return NULL;
261 while (*av_masks) {
Lars-Peter Clausen1e1ec282015-05-29 18:14:22 +0200262 if (strict) {
263 if (bitmap_equal(mask, av_masks, masklength))
264 return av_masks;
265 } else {
266 if (bitmap_subset(mask, av_masks, masklength))
267 return av_masks;
268 }
Lars-Peter Clausen217a5cf2014-11-26 18:55:09 +0100269 av_masks += BITS_TO_LONGS(masklength);
270 }
271 return NULL;
272}
273
274static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
275 const unsigned long *mask)
276{
277 if (!indio_dev->setup_ops->validate_scan_mask)
278 return true;
279
280 return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
281}
282
283/**
284 * iio_scan_mask_set() - set particular bit in the scan mask
285 * @indio_dev: the iio device
286 * @buffer: the buffer whose scan mask we are interested in
287 * @bit: the bit to be set.
288 *
289 * Note that at this point we have no way of knowing what other
290 * buffers might request, hence this code only verifies that the
291 * individual buffers request is plausible.
292 */
293static int iio_scan_mask_set(struct iio_dev *indio_dev,
294 struct iio_buffer *buffer, int bit)
295{
296 const unsigned long *mask;
297 unsigned long *trialmask;
298
299 trialmask = kmalloc(sizeof(*trialmask)*
300 BITS_TO_LONGS(indio_dev->masklength),
301 GFP_KERNEL);
302
303 if (trialmask == NULL)
304 return -ENOMEM;
305 if (!indio_dev->masklength) {
306 WARN_ON("Trying to set scanmask prior to registering buffer\n");
307 goto err_invalid_mask;
308 }
309 bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
310 set_bit(bit, trialmask);
311
312 if (!iio_validate_scan_mask(indio_dev, trialmask))
313 goto err_invalid_mask;
314
315 if (indio_dev->available_scan_masks) {
316 mask = iio_scan_mask_match(indio_dev->available_scan_masks,
317 indio_dev->masklength,
Lars-Peter Clausen1e1ec282015-05-29 18:14:22 +0200318 trialmask, false);
Lars-Peter Clausen217a5cf2014-11-26 18:55:09 +0100319 if (!mask)
320 goto err_invalid_mask;
321 }
322 bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
323
324 kfree(trialmask);
325
326 return 0;
327
328err_invalid_mask:
329 kfree(trialmask);
330 return -EINVAL;
331}
332
Jonathan Cameron14555b12011-09-21 11:15:57 +0100333static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
334{
335 clear_bit(bit, buffer->scan_mask);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100336 return 0;
337}
338
339static ssize_t iio_scan_el_store(struct device *dev,
340 struct device_attribute *attr,
341 const char *buf,
342 size_t len)
343{
Jonathan Camerona714af22012-04-21 10:09:32 +0100344 int ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100345 bool state;
Lars-Peter Clausene53f5ac2012-05-12 15:39:33 +0200346 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100347 struct iio_buffer *buffer = indio_dev->buffer;
348 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
349
Jonathan Camerona714af22012-04-21 10:09:32 +0100350 ret = strtobool(buf, &state);
351 if (ret < 0)
352 return ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100353 mutex_lock(&indio_dev->mlock);
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +0100354 if (iio_buffer_is_active(indio_dev->buffer)) {
Jonathan Cameron14555b12011-09-21 11:15:57 +0100355 ret = -EBUSY;
356 goto error_ret;
357 }
Jonathan Cameronf79a9092011-12-05 22:18:29 +0000358 ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100359 if (ret < 0)
360 goto error_ret;
361 if (!state && ret) {
362 ret = iio_scan_mask_clear(buffer, this_attr->address);
363 if (ret)
364 goto error_ret;
365 } else if (state && !ret) {
Jonathan Cameronf79a9092011-12-05 22:18:29 +0000366 ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100367 if (ret)
368 goto error_ret;
369 }
370
371error_ret:
372 mutex_unlock(&indio_dev->mlock);
373
Lars-Peter Clausen5a2a6e12011-12-08 18:35:53 +0100374 return ret < 0 ? ret : len;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100375
376}
377
378static ssize_t iio_scan_el_ts_show(struct device *dev,
379 struct device_attribute *attr,
380 char *buf)
381{
Lars-Peter Clausene53f5ac2012-05-12 15:39:33 +0200382 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Jonathan Cameronf8c6f4e2011-10-06 17:14:35 +0100383 return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100384}
385
386static ssize_t iio_scan_el_ts_store(struct device *dev,
387 struct device_attribute *attr,
388 const char *buf,
389 size_t len)
390{
Jonathan Camerona714af22012-04-21 10:09:32 +0100391 int ret;
Lars-Peter Clausene53f5ac2012-05-12 15:39:33 +0200392 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100393 bool state;
394
Jonathan Camerona714af22012-04-21 10:09:32 +0100395 ret = strtobool(buf, &state);
396 if (ret < 0)
397 return ret;
398
Jonathan Cameron14555b12011-09-21 11:15:57 +0100399 mutex_lock(&indio_dev->mlock);
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +0100400 if (iio_buffer_is_active(indio_dev->buffer)) {
Jonathan Cameron14555b12011-09-21 11:15:57 +0100401 ret = -EBUSY;
402 goto error_ret;
403 }
404 indio_dev->buffer->scan_timestamp = state;
405error_ret:
406 mutex_unlock(&indio_dev->mlock);
407
408 return ret ? ret : len;
409}
410
411static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
412 const struct iio_chan_spec *chan)
413{
414 int ret, attrcount = 0;
415 struct iio_buffer *buffer = indio_dev->buffer;
416
417 ret = __iio_add_chan_devattr("index",
418 chan,
419 &iio_show_scan_index,
420 NULL,
421 0,
Jonathan Cameron37044322013-09-08 14:57:00 +0100422 IIO_SEPARATE,
Jonathan Cameron14555b12011-09-21 11:15:57 +0100423 &indio_dev->dev,
424 &buffer->scan_el_dev_attr_list);
425 if (ret)
Hartmut Knaack92825ff2014-02-16 11:53:00 +0000426 return ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100427 attrcount++;
428 ret = __iio_add_chan_devattr("type",
429 chan,
430 &iio_show_fixed_type,
431 NULL,
432 0,
433 0,
434 &indio_dev->dev,
435 &buffer->scan_el_dev_attr_list);
436 if (ret)
Hartmut Knaack92825ff2014-02-16 11:53:00 +0000437 return ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100438 attrcount++;
439 if (chan->type != IIO_TIMESTAMP)
440 ret = __iio_add_chan_devattr("en",
441 chan,
442 &iio_scan_el_show,
443 &iio_scan_el_store,
444 chan->scan_index,
445 0,
446 &indio_dev->dev,
447 &buffer->scan_el_dev_attr_list);
448 else
449 ret = __iio_add_chan_devattr("en",
450 chan,
451 &iio_scan_el_ts_show,
452 &iio_scan_el_ts_store,
453 chan->scan_index,
454 0,
455 &indio_dev->dev,
456 &buffer->scan_el_dev_attr_list);
Peter Meerwald95725882013-09-17 23:42:00 +0100457 if (ret)
Hartmut Knaack92825ff2014-02-16 11:53:00 +0000458 return ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100459 attrcount++;
460 ret = attrcount;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100461 return ret;
462}
463
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +0100464static ssize_t iio_buffer_read_length(struct device *dev,
465 struct device_attribute *attr,
466 char *buf)
Jonathan Cameron14555b12011-09-21 11:15:57 +0100467{
Lars-Peter Clausene53f5ac2012-05-12 15:39:33 +0200468 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100469 struct iio_buffer *buffer = indio_dev->buffer;
470
Lars-Peter Clausen37495662014-11-26 18:55:17 +0100471 return sprintf(buf, "%d\n", buffer->length);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100472}
Jonathan Cameron14555b12011-09-21 11:15:57 +0100473
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +0100474static ssize_t iio_buffer_write_length(struct device *dev,
475 struct device_attribute *attr,
476 const char *buf, size_t len)
Jonathan Cameron14555b12011-09-21 11:15:57 +0100477{
Lars-Peter Clausene53f5ac2012-05-12 15:39:33 +0200478 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100479 struct iio_buffer *buffer = indio_dev->buffer;
Lars-Peter Clausen948ad202012-10-18 14:47:00 +0100480 unsigned int val;
481 int ret;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100482
Lars-Peter Clausen948ad202012-10-18 14:47:00 +0100483 ret = kstrtouint(buf, 10, &val);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100484 if (ret)
485 return ret;
486
Lars-Peter Clausen37495662014-11-26 18:55:17 +0100487 if (val == buffer->length)
488 return len;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100489
Lars-Peter Clausene38c79e2011-12-19 15:23:44 +0100490 mutex_lock(&indio_dev->mlock);
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +0100491 if (iio_buffer_is_active(indio_dev->buffer)) {
Lars-Peter Clausene38c79e2011-12-19 15:23:44 +0100492 ret = -EBUSY;
493 } else {
Lars-Peter Clausen8d92db22014-11-26 18:55:16 +0100494 buffer->access->set_length(buffer, val);
Lars-Peter Clausene38c79e2011-12-19 15:23:44 +0100495 ret = 0;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100496 }
Josselin Costanzi37d34552015-03-22 20:33:38 +0200497 if (ret)
498 goto out;
499 if (buffer->length && buffer->length < buffer->watermark)
500 buffer->watermark = buffer->length;
501out:
Lars-Peter Clausene38c79e2011-12-19 15:23:44 +0100502 mutex_unlock(&indio_dev->mlock);
Jonathan Cameron14555b12011-09-21 11:15:57 +0100503
Lars-Peter Clausene38c79e2011-12-19 15:23:44 +0100504 return ret ? ret : len;
Jonathan Cameron14555b12011-09-21 11:15:57 +0100505}
Jonathan Cameron14555b12011-09-21 11:15:57 +0100506
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +0100507static ssize_t iio_buffer_show_enable(struct device *dev,
508 struct device_attribute *attr,
509 char *buf)
Jonathan Cameron14555b12011-09-21 11:15:57 +0100510{
Lars-Peter Clausene53f5ac2012-05-12 15:39:33 +0200511 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +0100512 return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
Jonathan Cameron14555b12011-09-21 11:15:57 +0100513}
Jonathan Cameron14555b12011-09-21 11:15:57 +0100514
Peter Meerwald183f4172013-09-18 22:10:00 +0100515static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
516 const unsigned long *mask, bool timestamp)
Jonathan Cameron959d2952011-12-05 21:37:13 +0000517{
Jonathan Cameron959d2952011-12-05 21:37:13 +0000518 const struct iio_chan_spec *ch;
519 unsigned bytes = 0;
520 int length, i;
Jonathan Cameron6b3b58e2012-04-21 10:09:33 +0100521
522 /* How much space will the demuxed element take? */
523 for_each_set_bit(i, mask,
524 indio_dev->masklength) {
525 ch = iio_find_channel_from_si(indio_dev, i);
Srinivas Pandruvada0ee85462014-04-29 00:51:00 +0100526 if (ch->scan_type.repeat > 1)
527 length = ch->scan_type.storagebits / 8 *
528 ch->scan_type.repeat;
529 else
530 length = ch->scan_type.storagebits / 8;
Jonathan Cameron6b3b58e2012-04-21 10:09:33 +0100531 bytes = ALIGN(bytes, length);
532 bytes += length;
533 }
534 if (timestamp) {
535 ch = iio_find_channel_from_si(indio_dev,
Jonathan Cameronf1264802012-04-21 10:09:34 +0100536 indio_dev->scan_index_timestamp);
Srinivas Pandruvada0ee85462014-04-29 00:51:00 +0100537 if (ch->scan_type.repeat > 1)
538 length = ch->scan_type.storagebits / 8 *
539 ch->scan_type.repeat;
540 else
541 length = ch->scan_type.storagebits / 8;
Jonathan Cameron6b3b58e2012-04-21 10:09:33 +0100542 bytes = ALIGN(bytes, length);
543 bytes += length;
544 }
545 return bytes;
546}
547
Lars-Peter Clausen9e69c932013-10-04 12:06:00 +0100548static void iio_buffer_activate(struct iio_dev *indio_dev,
549 struct iio_buffer *buffer)
550{
551 iio_buffer_get(buffer);
552 list_add(&buffer->buffer_list, &indio_dev->buffer_list);
553}
554
555static void iio_buffer_deactivate(struct iio_buffer *buffer)
556{
557 list_del_init(&buffer->buffer_list);
Josselin Costanzi37d34552015-03-22 20:33:38 +0200558 wake_up_interruptible(&buffer->pollq);
Lars-Peter Clausen9e69c932013-10-04 12:06:00 +0100559 iio_buffer_put(buffer);
560}
561
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200562static void iio_buffer_deactivate_all(struct iio_dev *indio_dev)
563{
564 struct iio_buffer *buffer, *_buffer;
565
566 list_for_each_entry_safe(buffer, _buffer,
567 &indio_dev->buffer_list, buffer_list)
568 iio_buffer_deactivate(buffer);
569}
570
Lars-Peter Clausen8e050992013-10-14 17:49:00 +0100571static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
572 struct iio_buffer *buffer)
573{
574 unsigned int bytes;
575
576 if (!buffer->access->set_bytes_per_datum)
577 return;
578
579 bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
580 buffer->scan_timestamp);
581
582 buffer->access->set_bytes_per_datum(buffer, bytes);
583}
584
Lars-Peter Clausenfcc1b2f2015-05-13 16:04:46 +0200585static int iio_buffer_request_update(struct iio_dev *indio_dev,
586 struct iio_buffer *buffer)
587{
588 int ret;
589
590 iio_buffer_update_bytes_per_datum(indio_dev, buffer);
591 if (buffer->access->request_update) {
592 ret = buffer->access->request_update(buffer);
593 if (ret) {
594 dev_dbg(&indio_dev->dev,
595 "Buffer not started: buffer parameter update failed (%d)\n",
596 ret);
597 return ret;
598 }
599 }
600
601 return 0;
602}
603
Lars-Peter Clausen248be5a2015-05-13 16:04:45 +0200604static void iio_free_scan_mask(struct iio_dev *indio_dev,
605 const unsigned long *mask)
606{
607 /* If the mask is dynamically allocated free it, otherwise do nothing */
608 if (!indio_dev->available_scan_masks)
609 kfree(mask);
610}
611
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200612struct iio_device_config {
613 unsigned int mode;
Lars-Peter Clausenf0566c02015-10-13 18:10:24 +0200614 unsigned int watermark;
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200615 const unsigned long *scan_mask;
616 unsigned int scan_bytes;
617 bool scan_timestamp;
618};
619
620static int iio_verify_update(struct iio_dev *indio_dev,
621 struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer,
622 struct iio_device_config *config)
623{
624 unsigned long *compound_mask;
625 const unsigned long *scan_mask;
Lars-Peter Clausen1e1ec282015-05-29 18:14:22 +0200626 bool strict_scanmask = false;
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200627 struct iio_buffer *buffer;
628 bool scan_timestamp;
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200629 unsigned int modes;
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200630
631 memset(config, 0, sizeof(*config));
632
633 /*
634 * If there is just one buffer and we are removing it there is nothing
635 * to verify.
636 */
637 if (remove_buffer && !insert_buffer &&
638 list_is_singular(&indio_dev->buffer_list))
639 return 0;
640
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200641 modes = indio_dev->modes;
642
643 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
644 if (buffer == remove_buffer)
645 continue;
646 modes &= buffer->access->modes;
Lars-Peter Clausenf0566c02015-10-13 18:10:24 +0200647 config->watermark = min(config->watermark, buffer->watermark);
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200648 }
649
Lars-Peter Clausenf0566c02015-10-13 18:10:24 +0200650 if (insert_buffer) {
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200651 modes &= insert_buffer->access->modes;
Lars-Peter Clausenf0566c02015-10-13 18:10:24 +0200652 config->watermark = min(config->watermark,
653 insert_buffer->watermark);
654 }
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200655
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200656 /* Definitely possible for devices to support both of these. */
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200657 if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200658 config->mode = INDIO_BUFFER_TRIGGERED;
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200659 } else if (modes & INDIO_BUFFER_HARDWARE) {
Lars-Peter Clausen1e1ec282015-05-29 18:14:22 +0200660 /*
661 * Keep things simple for now and only allow a single buffer to
662 * be connected in hardware mode.
663 */
664 if (insert_buffer && !list_empty(&indio_dev->buffer_list))
665 return -EINVAL;
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200666 config->mode = INDIO_BUFFER_HARDWARE;
Lars-Peter Clausen1e1ec282015-05-29 18:14:22 +0200667 strict_scanmask = true;
Lars-Peter Clausen225d59a2015-05-29 18:14:21 +0200668 } else if (modes & INDIO_BUFFER_SOFTWARE) {
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200669 config->mode = INDIO_BUFFER_SOFTWARE;
670 } else {
671 /* Can only occur on first buffer */
672 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
673 dev_dbg(&indio_dev->dev, "Buffer not started: no trigger\n");
674 return -EINVAL;
675 }
676
677 /* What scan mask do we actually have? */
678 compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
679 sizeof(long), GFP_KERNEL);
680 if (compound_mask == NULL)
681 return -ENOMEM;
682
683 scan_timestamp = false;
684
685 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
686 if (buffer == remove_buffer)
687 continue;
688 bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
689 indio_dev->masklength);
690 scan_timestamp |= buffer->scan_timestamp;
691 }
692
693 if (insert_buffer) {
694 bitmap_or(compound_mask, compound_mask,
695 insert_buffer->scan_mask, indio_dev->masklength);
696 scan_timestamp |= insert_buffer->scan_timestamp;
697 }
698
699 if (indio_dev->available_scan_masks) {
700 scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks,
701 indio_dev->masklength,
Lars-Peter Clausen1e1ec282015-05-29 18:14:22 +0200702 compound_mask,
703 strict_scanmask);
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200704 kfree(compound_mask);
705 if (scan_mask == NULL)
706 return -EINVAL;
707 } else {
708 scan_mask = compound_mask;
709 }
710
711 config->scan_bytes = iio_compute_scan_bytes(indio_dev,
712 scan_mask, scan_timestamp);
713 config->scan_mask = scan_mask;
714 config->scan_timestamp = scan_timestamp;
715
716 return 0;
717}
718
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200719static int iio_enable_buffers(struct iio_dev *indio_dev,
720 struct iio_device_config *config)
721{
722 int ret;
723
724 indio_dev->active_scan_mask = config->scan_mask;
725 indio_dev->scan_timestamp = config->scan_timestamp;
726 indio_dev->scan_bytes = config->scan_bytes;
727
728 iio_update_demux(indio_dev);
729
730 /* Wind up again */
731 if (indio_dev->setup_ops->preenable) {
732 ret = indio_dev->setup_ops->preenable(indio_dev);
733 if (ret) {
734 dev_dbg(&indio_dev->dev,
735 "Buffer not started: buffer preenable failed (%d)\n", ret);
736 goto err_undo_config;
737 }
738 }
739
740 if (indio_dev->info->update_scan_mode) {
741 ret = indio_dev->info
742 ->update_scan_mode(indio_dev,
743 indio_dev->active_scan_mask);
744 if (ret < 0) {
745 dev_dbg(&indio_dev->dev,
746 "Buffer not started: update scan mode failed (%d)\n",
747 ret);
748 goto err_run_postdisable;
749 }
750 }
751
Lars-Peter Clausenf0566c02015-10-13 18:10:24 +0200752 if (indio_dev->info->hwfifo_set_watermark)
753 indio_dev->info->hwfifo_set_watermark(indio_dev,
754 config->watermark);
755
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200756 indio_dev->currentmode = config->mode;
757
758 if (indio_dev->setup_ops->postenable) {
759 ret = indio_dev->setup_ops->postenable(indio_dev);
760 if (ret) {
761 dev_dbg(&indio_dev->dev,
762 "Buffer not started: postenable failed (%d)\n", ret);
763 goto err_run_postdisable;
764 }
765 }
766
767 return 0;
768
769err_run_postdisable:
770 indio_dev->currentmode = INDIO_DIRECT_MODE;
771 if (indio_dev->setup_ops->postdisable)
772 indio_dev->setup_ops->postdisable(indio_dev);
773err_undo_config:
774 indio_dev->active_scan_mask = NULL;
775
776 return ret;
777}
778
779static int iio_disable_buffers(struct iio_dev *indio_dev)
780{
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200781 int ret = 0;
782 int ret2;
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200783
784 /* Wind down existing buffers - iff there are any */
785 if (list_empty(&indio_dev->buffer_list))
786 return 0;
787
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200788 /*
789 * If things go wrong at some step in disable we still need to continue
790 * to perform the other steps, otherwise we leave the device in a
791 * inconsistent state. We return the error code for the first error we
792 * encountered.
793 */
794
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200795 if (indio_dev->setup_ops->predisable) {
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200796 ret2 = indio_dev->setup_ops->predisable(indio_dev);
797 if (ret2 && !ret)
798 ret = ret2;
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200799 }
800
801 indio_dev->currentmode = INDIO_DIRECT_MODE;
802
803 if (indio_dev->setup_ops->postdisable) {
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200804 ret2 = indio_dev->setup_ops->postdisable(indio_dev);
805 if (ret2 && !ret)
806 ret = ret2;
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200807 }
808
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200809 iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask);
810 indio_dev->active_scan_mask = NULL;
811
812 return ret;
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200813}
814
Lars-Peter Clausena9519452013-10-04 12:07:00 +0100815static int __iio_update_buffers(struct iio_dev *indio_dev,
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100816 struct iio_buffer *insert_buffer,
817 struct iio_buffer *remove_buffer)
Jonathan Cameron6b3b58e2012-04-21 10:09:33 +0100818{
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200819 struct iio_device_config new_config;
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200820 int ret;
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200821
822 ret = iio_verify_update(indio_dev, insert_buffer, remove_buffer,
823 &new_config);
824 if (ret)
825 return ret;
Jonathan Cameron959d2952011-12-05 21:37:13 +0000826
Lars-Peter Clausenfcc1b2f2015-05-13 16:04:46 +0200827 if (insert_buffer) {
828 ret = iio_buffer_request_update(indio_dev, insert_buffer);
829 if (ret)
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200830 goto err_free_config;
Lars-Peter Clausenfcc1b2f2015-05-13 16:04:46 +0200831 }
832
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200833 ret = iio_disable_buffers(indio_dev);
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200834 if (ret)
835 goto err_deactivate_all;
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100836
837 if (remove_buffer)
Lars-Peter Clausen9e69c932013-10-04 12:06:00 +0100838 iio_buffer_deactivate(remove_buffer);
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100839 if (insert_buffer)
Lars-Peter Clausen9e69c932013-10-04 12:06:00 +0100840 iio_buffer_activate(indio_dev, insert_buffer);
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100841
842 /* If no buffers in list, we are done */
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200843 if (list_empty(&indio_dev->buffer_list))
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100844 return 0;
Jonathan Cameron959d2952011-12-05 21:37:13 +0000845
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200846 ret = iio_enable_buffers(indio_dev, &new_config);
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200847 if (ret)
848 goto err_deactivate_all;
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100849
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200850 return 0;
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100851
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200852err_deactivate_all:
853 /*
854 * We've already verified that the config is valid earlier. If things go
855 * wrong in either enable or disable the most likely reason is an IO
856 * error from the device. In this case there is no good recovery
857 * strategy. Just make sure to disable everything and leave the device
858 * in a sane state. With a bit of luck the device might come back to
859 * life again later and userspace can try again.
860 */
861 iio_buffer_deactivate_all(indio_dev);
862
Lars-Peter Clausen6e509c42015-05-18 13:34:47 +0200863err_free_config:
864 iio_free_scan_mask(indio_dev, new_config.scan_mask);
865 return ret;
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100866}
Lars-Peter Clausena9519452013-10-04 12:07:00 +0100867
868int iio_update_buffers(struct iio_dev *indio_dev,
869 struct iio_buffer *insert_buffer,
870 struct iio_buffer *remove_buffer)
871{
872 int ret;
873
Lars-Peter Clausen3909fab2013-10-04 12:07:00 +0100874 if (insert_buffer == remove_buffer)
875 return 0;
876
Lars-Peter Clausena9519452013-10-04 12:07:00 +0100877 mutex_lock(&indio_dev->info_exist_lock);
878 mutex_lock(&indio_dev->mlock);
879
Lars-Peter Clausen3909fab2013-10-04 12:07:00 +0100880 if (insert_buffer && iio_buffer_is_active(insert_buffer))
881 insert_buffer = NULL;
882
883 if (remove_buffer && !iio_buffer_is_active(remove_buffer))
884 remove_buffer = NULL;
885
886 if (!insert_buffer && !remove_buffer) {
887 ret = 0;
888 goto out_unlock;
889 }
890
Lars-Peter Clausena9519452013-10-04 12:07:00 +0100891 if (indio_dev->info == NULL) {
892 ret = -ENODEV;
893 goto out_unlock;
894 }
895
896 ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
897
898out_unlock:
899 mutex_unlock(&indio_dev->mlock);
900 mutex_unlock(&indio_dev->info_exist_lock);
901
902 return ret;
903}
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100904EXPORT_SYMBOL_GPL(iio_update_buffers);
905
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200906void iio_disable_all_buffers(struct iio_dev *indio_dev)
907{
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200908 iio_disable_buffers(indio_dev);
Lars-Peter Clausen12501862015-05-18 13:34:49 +0200909 iio_buffer_deactivate_all(indio_dev);
Lars-Peter Clausen623d74e2015-05-18 13:34:48 +0200910}
911
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +0100912static ssize_t iio_buffer_store_enable(struct device *dev,
913 struct device_attribute *attr,
914 const char *buf,
915 size_t len)
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100916{
917 int ret;
918 bool requested_state;
919 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100920 bool inlist;
921
922 ret = strtobool(buf, &requested_state);
923 if (ret < 0)
924 return ret;
925
926 mutex_lock(&indio_dev->mlock);
927
928 /* Find out if it is in the list */
Lars-Peter Clausen705ee2c2013-09-15 16:31:00 +0100929 inlist = iio_buffer_is_active(indio_dev->buffer);
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100930 /* Already in desired state */
931 if (inlist == requested_state)
932 goto done;
933
934 if (requested_state)
Lars-Peter Clausena9519452013-10-04 12:07:00 +0100935 ret = __iio_update_buffers(indio_dev,
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100936 indio_dev->buffer, NULL);
937 else
Lars-Peter Clausena9519452013-10-04 12:07:00 +0100938 ret = __iio_update_buffers(indio_dev,
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100939 NULL, indio_dev->buffer);
940
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100941done:
942 mutex_unlock(&indio_dev->mlock);
943 return (ret < 0) ? ret : len;
944}
Jonathan Cameron84b36ce2012-06-30 20:06:00 +0100945
Lars-Peter Clausend967cb62014-11-26 18:55:14 +0100946static const char * const iio_scan_elements_group_name = "scan_elements";
947
Josselin Costanzi37d34552015-03-22 20:33:38 +0200948static ssize_t iio_buffer_show_watermark(struct device *dev,
949 struct device_attribute *attr,
950 char *buf)
951{
952 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
953 struct iio_buffer *buffer = indio_dev->buffer;
954
955 return sprintf(buf, "%u\n", buffer->watermark);
956}
957
958static ssize_t iio_buffer_store_watermark(struct device *dev,
959 struct device_attribute *attr,
960 const char *buf,
961 size_t len)
962{
963 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
964 struct iio_buffer *buffer = indio_dev->buffer;
965 unsigned int val;
966 int ret;
967
968 ret = kstrtouint(buf, 10, &val);
969 if (ret)
970 return ret;
971 if (!val)
972 return -EINVAL;
973
974 mutex_lock(&indio_dev->mlock);
975
976 if (val > buffer->length) {
977 ret = -EINVAL;
978 goto out;
979 }
980
981 if (iio_buffer_is_active(indio_dev->buffer)) {
982 ret = -EBUSY;
983 goto out;
984 }
985
986 buffer->watermark = val;
987out:
988 mutex_unlock(&indio_dev->mlock);
989
990 return ret ? ret : len;
991}
992
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +0100993static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
994 iio_buffer_write_length);
Lars-Peter Clausen8d92db22014-11-26 18:55:16 +0100995static struct device_attribute dev_attr_length_ro = __ATTR(length,
996 S_IRUGO, iio_buffer_read_length, NULL);
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +0100997static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
998 iio_buffer_show_enable, iio_buffer_store_enable);
Josselin Costanzi37d34552015-03-22 20:33:38 +0200999static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
1000 iio_buffer_show_watermark, iio_buffer_store_watermark);
Lars-Peter Clausenb4406552015-10-13 18:10:26 +02001001static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark,
1002 S_IRUGO, iio_buffer_show_watermark, NULL);
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +01001003
Octavian Purdila6da9b382015-01-31 02:00:00 +02001004static struct attribute *iio_buffer_attrs[] = {
1005 &dev_attr_length.attr,
1006 &dev_attr_enable.attr,
Josselin Costanzi37d34552015-03-22 20:33:38 +02001007 &dev_attr_watermark.attr,
Octavian Purdila6da9b382015-01-31 02:00:00 +02001008};
1009
Lars-Peter Clausend967cb62014-11-26 18:55:14 +01001010int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
1011{
1012 struct iio_dev_attr *p;
1013 struct attribute **attr;
1014 struct iio_buffer *buffer = indio_dev->buffer;
1015 int ret, i, attrn, attrcount, attrcount_orig = 0;
1016 const struct iio_chan_spec *channels;
1017
Lars-Peter Clausen629bc022015-05-29 18:14:20 +02001018 channels = indio_dev->channels;
1019 if (channels) {
1020 int ml = indio_dev->masklength;
1021
1022 for (i = 0; i < indio_dev->num_channels; i++)
1023 ml = max(ml, channels[i].scan_index + 1);
1024 indio_dev->masklength = ml;
1025 }
1026
Lars-Peter Clausend967cb62014-11-26 18:55:14 +01001027 if (!buffer)
1028 return 0;
1029
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +01001030 attrcount = 0;
1031 if (buffer->attrs) {
1032 while (buffer->attrs[attrcount] != NULL)
1033 attrcount++;
1034 }
1035
Octavian Purdila6da9b382015-01-31 02:00:00 +02001036 attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1,
1037 sizeof(struct attribute *), GFP_KERNEL);
1038 if (!attr)
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +01001039 return -ENOMEM;
1040
Octavian Purdila6da9b382015-01-31 02:00:00 +02001041 memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
1042 if (!buffer->access->set_length)
1043 attr[0] = &dev_attr_length_ro.attr;
1044
Lars-Peter Clausenb4406552015-10-13 18:10:26 +02001045 if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK)
1046 attr[2] = &dev_attr_watermark_ro.attr;
1047
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +01001048 if (buffer->attrs)
Octavian Purdila6da9b382015-01-31 02:00:00 +02001049 memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
1050 sizeof(struct attribute *) * attrcount);
1051
1052 attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL;
1053
1054 buffer->buffer_group.name = "buffer";
1055 buffer->buffer_group.attrs = attr;
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +01001056
1057 indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group;
1058
Lars-Peter Clausend967cb62014-11-26 18:55:14 +01001059 if (buffer->scan_el_attrs != NULL) {
1060 attr = buffer->scan_el_attrs->attrs;
1061 while (*attr++ != NULL)
1062 attrcount_orig++;
1063 }
1064 attrcount = attrcount_orig;
1065 INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
1066 channels = indio_dev->channels;
1067 if (channels) {
1068 /* new magic */
1069 for (i = 0; i < indio_dev->num_channels; i++) {
1070 if (channels[i].scan_index < 0)
1071 continue;
1072
Lars-Peter Clausend967cb62014-11-26 18:55:14 +01001073 ret = iio_buffer_add_channel_sysfs(indio_dev,
1074 &channels[i]);
1075 if (ret < 0)
1076 goto error_cleanup_dynamic;
1077 attrcount += ret;
1078 if (channels[i].type == IIO_TIMESTAMP)
1079 indio_dev->scan_index_timestamp =
1080 channels[i].scan_index;
1081 }
1082 if (indio_dev->masklength && buffer->scan_mask == NULL) {
1083 buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
1084 sizeof(*buffer->scan_mask),
1085 GFP_KERNEL);
1086 if (buffer->scan_mask == NULL) {
1087 ret = -ENOMEM;
1088 goto error_cleanup_dynamic;
1089 }
1090 }
1091 }
1092
1093 buffer->scan_el_group.name = iio_scan_elements_group_name;
1094
1095 buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
1096 sizeof(buffer->scan_el_group.attrs[0]),
1097 GFP_KERNEL);
1098 if (buffer->scan_el_group.attrs == NULL) {
1099 ret = -ENOMEM;
1100 goto error_free_scan_mask;
1101 }
1102 if (buffer->scan_el_attrs)
1103 memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
1104 sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
1105 attrn = attrcount_orig;
1106
1107 list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
1108 buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
1109 indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
1110
1111 return 0;
1112
1113error_free_scan_mask:
1114 kfree(buffer->scan_mask);
1115error_cleanup_dynamic:
1116 iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +01001117 kfree(indio_dev->buffer->buffer_group.attrs);
Lars-Peter Clausend967cb62014-11-26 18:55:14 +01001118
1119 return ret;
1120}
1121
1122void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev)
1123{
1124 if (!indio_dev->buffer)
1125 return;
1126
1127 kfree(indio_dev->buffer->scan_mask);
Lars-Peter Clausen08e7e0a2014-11-26 18:55:15 +01001128 kfree(indio_dev->buffer->buffer_group.attrs);
Lars-Peter Clausend967cb62014-11-26 18:55:14 +01001129 kfree(indio_dev->buffer->scan_el_group.attrs);
1130 iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
1131}
1132
Jonathan Cameron14555b12011-09-21 11:15:57 +01001133/**
Lars-Peter Clausen81636632012-07-09 10:00:00 +01001134 * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
1135 * @indio_dev: the iio device
1136 * @mask: scan mask to be checked
1137 *
1138 * Return true if exactly one bit is set in the scan mask, false otherwise. It
1139 * can be used for devices where only one channel can be active for sampling at
1140 * a time.
1141 */
1142bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
1143 const unsigned long *mask)
1144{
1145 return bitmap_weight(mask, indio_dev->masklength) == 1;
1146}
1147EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
1148
Jonathan Cameronf79a9092011-12-05 22:18:29 +00001149int iio_scan_mask_query(struct iio_dev *indio_dev,
1150 struct iio_buffer *buffer, int bit)
Jonathan Cameron14555b12011-09-21 11:15:57 +01001151{
Jonathan Cameronf8c6f4e2011-10-06 17:14:35 +01001152 if (bit > indio_dev->masklength)
Jonathan Cameron14555b12011-09-21 11:15:57 +01001153 return -EINVAL;
1154
1155 if (!buffer->scan_mask)
1156 return 0;
Jonathan Cameron14555b12011-09-21 11:15:57 +01001157
Alec Berg2076a202014-03-19 18:50:00 +00001158 /* Ensure return value is 0 or 1. */
1159 return !!test_bit(bit, buffer->scan_mask);
Jonathan Cameron14555b12011-09-21 11:15:57 +01001160};
1161EXPORT_SYMBOL_GPL(iio_scan_mask_query);
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001162
1163/**
Cristina Opriceana01236352015-07-24 16:18:09 +03001164 * struct iio_demux_table - table describing demux memcpy ops
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001165 * @from: index to copy from
Peter Meerwald99698b42012-08-26 13:43:00 +01001166 * @to: index to copy to
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001167 * @length: how many bytes to copy
1168 * @l: list head used for management
1169 */
1170struct iio_demux_table {
1171 unsigned from;
1172 unsigned to;
1173 unsigned length;
1174 struct list_head l;
1175};
1176
Lars-Peter Clausen5d65d922013-09-15 17:50:00 +01001177static const void *iio_demux(struct iio_buffer *buffer,
1178 const void *datain)
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001179{
1180 struct iio_demux_table *t;
1181
1182 if (list_empty(&buffer->demux_list))
1183 return datain;
1184 list_for_each_entry(t, &buffer->demux_list, l)
1185 memcpy(buffer->demux_bounce + t->to,
1186 datain + t->from, t->length);
1187
1188 return buffer->demux_bounce;
1189}
1190
Lars-Peter Clausen5d65d922013-09-15 17:50:00 +01001191static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001192{
Lars-Peter Clausen5d65d922013-09-15 17:50:00 +01001193 const void *dataout = iio_demux(buffer, data);
Josselin Costanzi37d34552015-03-22 20:33:38 +02001194 int ret;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001195
Josselin Costanzi37d34552015-03-22 20:33:38 +02001196 ret = buffer->access->store_to(buffer, dataout);
1197 if (ret)
1198 return ret;
1199
1200 /*
1201 * We can't just test for watermark to decide if we wake the poll queue
1202 * because read may request less samples than the watermark.
1203 */
1204 wake_up_interruptible_poll(&buffer->pollq, POLLIN | POLLRDNORM);
1205 return 0;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001206}
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001207
Jonathan Cameron842cd102012-04-21 10:09:45 +01001208static void iio_buffer_demux_free(struct iio_buffer *buffer)
1209{
1210 struct iio_demux_table *p, *q;
1211 list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
1212 list_del(&p->l);
1213 kfree(p);
1214 }
1215}
1216
Jonathan Cameron84b36ce2012-06-30 20:06:00 +01001217
Lars-Peter Clausen5d65d922013-09-15 17:50:00 +01001218int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
Jonathan Cameron84b36ce2012-06-30 20:06:00 +01001219{
1220 int ret;
1221 struct iio_buffer *buf;
1222
1223 list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) {
1224 ret = iio_push_to_buffer(buf, data);
1225 if (ret < 0)
1226 return ret;
1227 }
1228
1229 return 0;
1230}
1231EXPORT_SYMBOL_GPL(iio_push_to_buffers);
1232
Lars-Peter Clausencbe88bc2014-07-17 16:59:00 +01001233static int iio_buffer_add_demux(struct iio_buffer *buffer,
1234 struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc,
1235 unsigned int length)
1236{
1237
1238 if (*p && (*p)->from + (*p)->length == in_loc &&
1239 (*p)->to + (*p)->length == out_loc) {
1240 (*p)->length += length;
1241 } else {
Jonathan Cameron7cdca1782014-08-08 09:43:00 +01001242 *p = kmalloc(sizeof(**p), GFP_KERNEL);
Lars-Peter Clausencbe88bc2014-07-17 16:59:00 +01001243 if (*p == NULL)
1244 return -ENOMEM;
1245 (*p)->from = in_loc;
1246 (*p)->to = out_loc;
1247 (*p)->length = length;
1248 list_add_tail(&(*p)->l, &buffer->demux_list);
1249 }
1250
1251 return 0;
1252}
1253
Jonathan Cameron84b36ce2012-06-30 20:06:00 +01001254static int iio_buffer_update_demux(struct iio_dev *indio_dev,
1255 struct iio_buffer *buffer)
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001256{
1257 const struct iio_chan_spec *ch;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001258 int ret, in_ind = -1, out_ind, length;
1259 unsigned in_loc = 0, out_loc = 0;
Lars-Peter Clausencbe88bc2014-07-17 16:59:00 +01001260 struct iio_demux_table *p = NULL;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001261
1262 /* Clear out any old demux */
Jonathan Cameron842cd102012-04-21 10:09:45 +01001263 iio_buffer_demux_free(buffer);
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001264 kfree(buffer->demux_bounce);
1265 buffer->demux_bounce = NULL;
1266
1267 /* First work out which scan mode we will actually have */
1268 if (bitmap_equal(indio_dev->active_scan_mask,
1269 buffer->scan_mask,
1270 indio_dev->masklength))
1271 return 0;
1272
1273 /* Now we have the two masks, work from least sig and build up sizes */
1274 for_each_set_bit(out_ind,
Lars-Peter Clausen61bd55c2014-07-17 16:59:00 +01001275 buffer->scan_mask,
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001276 indio_dev->masklength) {
1277 in_ind = find_next_bit(indio_dev->active_scan_mask,
1278 indio_dev->masklength,
1279 in_ind + 1);
1280 while (in_ind != out_ind) {
1281 in_ind = find_next_bit(indio_dev->active_scan_mask,
1282 indio_dev->masklength,
1283 in_ind + 1);
1284 ch = iio_find_channel_from_si(indio_dev, in_ind);
Srinivas Pandruvada0ee85462014-04-29 00:51:00 +01001285 if (ch->scan_type.repeat > 1)
1286 length = ch->scan_type.storagebits / 8 *
1287 ch->scan_type.repeat;
1288 else
1289 length = ch->scan_type.storagebits / 8;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001290 /* Make sure we are aligned */
Lars-Peter Clausen61072db2014-07-17 16:59:00 +01001291 in_loc = roundup(in_loc, length) + length;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001292 }
1293 ch = iio_find_channel_from_si(indio_dev, in_ind);
Srinivas Pandruvada0ee85462014-04-29 00:51:00 +01001294 if (ch->scan_type.repeat > 1)
1295 length = ch->scan_type.storagebits / 8 *
1296 ch->scan_type.repeat;
1297 else
1298 length = ch->scan_type.storagebits / 8;
Lars-Peter Clausen61072db2014-07-17 16:59:00 +01001299 out_loc = roundup(out_loc, length);
1300 in_loc = roundup(in_loc, length);
Lars-Peter Clausencbe88bc2014-07-17 16:59:00 +01001301 ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
1302 if (ret)
1303 goto error_clear_mux_table;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001304 out_loc += length;
1305 in_loc += length;
1306 }
1307 /* Relies on scan_timestamp being last */
1308 if (buffer->scan_timestamp) {
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001309 ch = iio_find_channel_from_si(indio_dev,
Jonathan Cameronf1264802012-04-21 10:09:34 +01001310 indio_dev->scan_index_timestamp);
Srinivas Pandruvada0ee85462014-04-29 00:51:00 +01001311 if (ch->scan_type.repeat > 1)
1312 length = ch->scan_type.storagebits / 8 *
1313 ch->scan_type.repeat;
1314 else
1315 length = ch->scan_type.storagebits / 8;
Lars-Peter Clausen61072db2014-07-17 16:59:00 +01001316 out_loc = roundup(out_loc, length);
1317 in_loc = roundup(in_loc, length);
Lars-Peter Clausencbe88bc2014-07-17 16:59:00 +01001318 ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
1319 if (ret)
1320 goto error_clear_mux_table;
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001321 out_loc += length;
1322 in_loc += length;
1323 }
1324 buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
1325 if (buffer->demux_bounce == NULL) {
1326 ret = -ENOMEM;
1327 goto error_clear_mux_table;
1328 }
1329 return 0;
1330
1331error_clear_mux_table:
Jonathan Cameron842cd102012-04-21 10:09:45 +01001332 iio_buffer_demux_free(buffer);
1333
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001334 return ret;
1335}
Jonathan Cameron84b36ce2012-06-30 20:06:00 +01001336
1337int iio_update_demux(struct iio_dev *indio_dev)
1338{
1339 struct iio_buffer *buffer;
1340 int ret;
1341
1342 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
1343 ret = iio_buffer_update_demux(indio_dev, buffer);
1344 if (ret < 0)
1345 goto error_clear_mux_table;
1346 }
1347 return 0;
1348
1349error_clear_mux_table:
1350 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
1351 iio_buffer_demux_free(buffer);
1352
1353 return ret;
1354}
Jonathan Cameron5ada4ea2011-12-05 21:37:14 +00001355EXPORT_SYMBOL_GPL(iio_update_demux);
Lars-Peter Clausen9e69c932013-10-04 12:06:00 +01001356
1357/**
1358 * iio_buffer_release() - Free a buffer's resources
1359 * @ref: Pointer to the kref embedded in the iio_buffer struct
1360 *
1361 * This function is called when the last reference to the buffer has been
1362 * dropped. It will typically free all resources allocated by the buffer. Do not
1363 * call this function manually, always use iio_buffer_put() when done using a
1364 * buffer.
1365 */
1366static void iio_buffer_release(struct kref *ref)
1367{
1368 struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
1369
1370 buffer->access->release(buffer);
1371}
1372
1373/**
1374 * iio_buffer_get() - Grab a reference to the buffer
1375 * @buffer: The buffer to grab a reference for, may be NULL
1376 *
1377 * Returns the pointer to the buffer that was passed into the function.
1378 */
1379struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
1380{
1381 if (buffer)
1382 kref_get(&buffer->ref);
1383
1384 return buffer;
1385}
1386EXPORT_SYMBOL_GPL(iio_buffer_get);
1387
1388/**
1389 * iio_buffer_put() - Release the reference to the buffer
1390 * @buffer: The buffer to release the reference for, may be NULL
1391 */
1392void iio_buffer_put(struct iio_buffer *buffer)
1393{
1394 if (buffer)
1395 kref_put(&buffer->ref, iio_buffer_release);
1396}
1397EXPORT_SYMBOL_GPL(iio_buffer_put);