1 // SPDX-License-Identifier: GPL-2.0-only
2 /* The industrial I/O core
4 * Copyright (c) 2008 Jonathan Cameron
6 * Handling of buffer allocation / resizing.
8 * Things to look at here.
9 * - Better memory allocation techniques?
10 * - Alternative access techniques?
12 #include <linux/anon_inodes.h>
13 #include <linux/kernel.h>
14 #include <linux/export.h>
15 #include <linux/device.h>
16 #include <linux/file.h>
18 #include <linux/cdev.h>
19 #include <linux/slab.h>
20 #include <linux/poll.h>
21 #include <linux/sched/signal.h>
23 #include <linux/iio/iio.h>
24 #include <linux/iio/iio-opaque.h>
26 #include "iio_core_trigger.h"
27 #include <linux/iio/sysfs.h>
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/buffer_impl.h>
31 static const char * const iio_endian_prefix[] = {
36 static bool iio_buffer_is_active(struct iio_buffer *buf)
38 return !list_empty(&buf->buffer_list);
41 static size_t iio_buffer_data_available(struct iio_buffer *buf)
43 return buf->access->data_available(buf);
46 static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
47 struct iio_buffer *buf, size_t required)
49 if (!indio_dev->info->hwfifo_flush_to_buffer)
52 return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
55 static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
56 size_t to_wait, int to_flush)
61 /* wakeup if the device was unregistered */
65 /* drain the buffer if it was disabled */
66 if (!iio_buffer_is_active(buf)) {
67 to_wait = min_t(size_t, to_wait, 1);
71 avail = iio_buffer_data_available(buf);
73 if (avail >= to_wait) {
74 /* force a flush for non-blocking reads */
75 if (!to_wait && avail < to_flush)
76 iio_buffer_flush_hwfifo(indio_dev, buf,
82 flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
87 if (avail + flushed >= to_wait)
94 * iio_buffer_read() - chrdev read for buffer access
95 * @filp: File structure pointer for the char device
96 * @buf: Destination buffer for iio buffer read
97 * @n: First n bytes to read
98 * @f_ps: Long offset provided by the user as a seek position
100 * This function relies on all buffer implementations having an
101 * iio_buffer as their first element.
103 * Return: negative values corresponding to error codes or ret != 0
104 * for ending the reading activity
106 static ssize_t iio_buffer_read(struct file *filp, char __user *buf,
107 size_t n, loff_t *f_ps)
109 struct iio_dev_buffer_pair *ib = filp->private_data;
110 struct iio_buffer *rb = ib->buffer;
111 struct iio_dev *indio_dev = ib->indio_dev;
112 DEFINE_WAIT_FUNC(wait, woken_wake_function);
117 if (!indio_dev->info)
120 if (!rb || !rb->access->read)
123 if (rb->direction != IIO_BUFFER_DIRECTION_IN)
126 datum_size = rb->bytes_per_datum;
129 * If datum_size is 0 there will never be anything to read from the
130 * buffer, so signal end of file now.
135 if (filp->f_flags & O_NONBLOCK)
138 to_wait = min_t(size_t, n / datum_size, rb->watermark);
140 add_wait_queue(&rb->pollq, &wait);
142 if (!indio_dev->info) {
147 if (!iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size)) {
148 if (signal_pending(current)) {
153 wait_woken(&wait, TASK_INTERRUPTIBLE,
154 MAX_SCHEDULE_TIMEOUT);
158 ret = rb->access->read(rb, n, buf);
159 if (ret == 0 && (filp->f_flags & O_NONBLOCK))
162 remove_wait_queue(&rb->pollq, &wait);
167 static size_t iio_buffer_space_available(struct iio_buffer *buf)
169 if (buf->access->space_available)
170 return buf->access->space_available(buf);
175 static ssize_t iio_buffer_write(struct file *filp, const char __user *buf,
176 size_t n, loff_t *f_ps)
178 struct iio_dev_buffer_pair *ib = filp->private_data;
179 struct iio_buffer *rb = ib->buffer;
180 struct iio_dev *indio_dev = ib->indio_dev;
181 DEFINE_WAIT_FUNC(wait, woken_wake_function);
185 if (!indio_dev->info)
188 if (!rb || !rb->access->write)
191 if (rb->direction != IIO_BUFFER_DIRECTION_OUT)
195 add_wait_queue(&rb->pollq, &wait);
197 if (indio_dev->info == NULL)
200 if (!iio_buffer_space_available(rb)) {
201 if (signal_pending(current)) {
206 wait_woken(&wait, TASK_INTERRUPTIBLE,
207 MAX_SCHEDULE_TIMEOUT);
211 ret = rb->access->write(rb, n - written, buf + written);
212 if (ret == 0 && (filp->f_flags & O_NONBLOCK))
217 if (written != n && !(filp->f_flags & O_NONBLOCK))
221 remove_wait_queue(&rb->pollq, &wait);
223 return ret < 0 ? ret : n;
227 * iio_buffer_poll() - poll the buffer to find out if it has data
228 * @filp: File structure pointer for device access
229 * @wait: Poll table structure pointer for which the driver adds
232 * Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading
233 * or 0 for other cases
235 static __poll_t iio_buffer_poll(struct file *filp,
236 struct poll_table_struct *wait)
238 struct iio_dev_buffer_pair *ib = filp->private_data;
239 struct iio_buffer *rb = ib->buffer;
240 struct iio_dev *indio_dev = ib->indio_dev;
242 if (!indio_dev->info || rb == NULL)
245 poll_wait(filp, &rb->pollq, wait);
247 switch (rb->direction) {
248 case IIO_BUFFER_DIRECTION_IN:
249 if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
250 return EPOLLIN | EPOLLRDNORM;
252 case IIO_BUFFER_DIRECTION_OUT:
253 if (iio_buffer_space_available(rb))
254 return EPOLLOUT | EPOLLWRNORM;
261 ssize_t iio_buffer_read_wrapper(struct file *filp, char __user *buf,
262 size_t n, loff_t *f_ps)
264 struct iio_dev_buffer_pair *ib = filp->private_data;
265 struct iio_buffer *rb = ib->buffer;
267 /* check if buffer was opened through new API */
268 if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
271 return iio_buffer_read(filp, buf, n, f_ps);
274 ssize_t iio_buffer_write_wrapper(struct file *filp, const char __user *buf,
275 size_t n, loff_t *f_ps)
277 struct iio_dev_buffer_pair *ib = filp->private_data;
278 struct iio_buffer *rb = ib->buffer;
280 /* check if buffer was opened through new API */
281 if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
284 return iio_buffer_write(filp, buf, n, f_ps);
287 __poll_t iio_buffer_poll_wrapper(struct file *filp,
288 struct poll_table_struct *wait)
290 struct iio_dev_buffer_pair *ib = filp->private_data;
291 struct iio_buffer *rb = ib->buffer;
293 /* check if buffer was opened through new API */
294 if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
297 return iio_buffer_poll(filp, wait);
301 * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
302 * @indio_dev: The IIO device
304 * Wakes up the event waitqueue used for poll(). Should usually
305 * be called when the device is unregistered.
307 void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
309 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
310 struct iio_buffer *buffer;
313 for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) {
314 buffer = iio_dev_opaque->attached_buffers[i];
315 wake_up(&buffer->pollq);
319 int iio_pop_from_buffer(struct iio_buffer *buffer, void *data)
321 if (!buffer || !buffer->access || !buffer->access->remove_from)
324 return buffer->access->remove_from(buffer, data);
326 EXPORT_SYMBOL_GPL(iio_pop_from_buffer);
328 void iio_buffer_init(struct iio_buffer *buffer)
330 INIT_LIST_HEAD(&buffer->demux_list);
331 INIT_LIST_HEAD(&buffer->buffer_list);
332 init_waitqueue_head(&buffer->pollq);
333 kref_init(&buffer->ref);
334 if (!buffer->watermark)
335 buffer->watermark = 1;
337 EXPORT_SYMBOL(iio_buffer_init);
339 void iio_device_detach_buffers(struct iio_dev *indio_dev)
341 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
342 struct iio_buffer *buffer;
345 for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) {
346 buffer = iio_dev_opaque->attached_buffers[i];
347 iio_buffer_put(buffer);
350 kfree(iio_dev_opaque->attached_buffers);
353 static ssize_t iio_show_scan_index(struct device *dev,
354 struct device_attribute *attr,
357 return sysfs_emit(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
360 static ssize_t iio_show_fixed_type(struct device *dev,
361 struct device_attribute *attr,
364 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
365 u8 type = this_attr->c->scan_type.endianness;
367 if (type == IIO_CPU) {
368 #ifdef __LITTLE_ENDIAN
374 if (this_attr->c->scan_type.repeat > 1)
375 return sysfs_emit(buf, "%s:%c%d/%dX%d>>%u\n",
376 iio_endian_prefix[type],
377 this_attr->c->scan_type.sign,
378 this_attr->c->scan_type.realbits,
379 this_attr->c->scan_type.storagebits,
380 this_attr->c->scan_type.repeat,
381 this_attr->c->scan_type.shift);
383 return sysfs_emit(buf, "%s:%c%d/%d>>%u\n",
384 iio_endian_prefix[type],
385 this_attr->c->scan_type.sign,
386 this_attr->c->scan_type.realbits,
387 this_attr->c->scan_type.storagebits,
388 this_attr->c->scan_type.shift);
391 static ssize_t iio_scan_el_show(struct device *dev,
392 struct device_attribute *attr,
396 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
398 /* Ensure ret is 0 or 1. */
399 ret = !!test_bit(to_iio_dev_attr(attr)->address,
402 return sysfs_emit(buf, "%d\n", ret);
405 /* Note NULL used as error indicator as it doesn't make sense. */
406 static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
407 unsigned int masklength,
408 const unsigned long *mask,
411 if (bitmap_empty(mask, masklength))
415 if (bitmap_equal(mask, av_masks, masklength))
418 if (bitmap_subset(mask, av_masks, masklength))
421 av_masks += BITS_TO_LONGS(masklength);
426 static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
427 const unsigned long *mask)
429 if (!indio_dev->setup_ops->validate_scan_mask)
432 return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
436 * iio_scan_mask_set() - set particular bit in the scan mask
437 * @indio_dev: the iio device
438 * @buffer: the buffer whose scan mask we are interested in
439 * @bit: the bit to be set.
441 * Note that at this point we have no way of knowing what other
442 * buffers might request, hence this code only verifies that the
443 * individual buffers request is plausible.
445 static int iio_scan_mask_set(struct iio_dev *indio_dev,
446 struct iio_buffer *buffer, int bit)
448 const unsigned long *mask;
449 unsigned long *trialmask;
451 if (!indio_dev->masklength) {
452 WARN(1, "Trying to set scanmask prior to registering buffer\n");
456 trialmask = bitmap_alloc(indio_dev->masklength, GFP_KERNEL);
459 bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
460 set_bit(bit, trialmask);
462 if (!iio_validate_scan_mask(indio_dev, trialmask))
463 goto err_invalid_mask;
465 if (indio_dev->available_scan_masks) {
466 mask = iio_scan_mask_match(indio_dev->available_scan_masks,
467 indio_dev->masklength,
470 goto err_invalid_mask;
472 bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
474 bitmap_free(trialmask);
479 bitmap_free(trialmask);
483 static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
485 clear_bit(bit, buffer->scan_mask);
489 static int iio_scan_mask_query(struct iio_dev *indio_dev,
490 struct iio_buffer *buffer, int bit)
492 if (bit > indio_dev->masklength)
495 if (!buffer->scan_mask)
498 /* Ensure return value is 0 or 1. */
499 return !!test_bit(bit, buffer->scan_mask);
502 static ssize_t iio_scan_el_store(struct device *dev,
503 struct device_attribute *attr,
509 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
510 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
511 struct iio_buffer *buffer = this_attr->buffer;
513 ret = kstrtobool(buf, &state);
516 mutex_lock(&indio_dev->mlock);
517 if (iio_buffer_is_active(buffer)) {
521 ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
525 ret = iio_scan_mask_clear(buffer, this_attr->address);
528 } else if (state && !ret) {
529 ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
535 mutex_unlock(&indio_dev->mlock);
537 return ret < 0 ? ret : len;
541 static ssize_t iio_scan_el_ts_show(struct device *dev,
542 struct device_attribute *attr,
545 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
547 return sysfs_emit(buf, "%d\n", buffer->scan_timestamp);
550 static ssize_t iio_scan_el_ts_store(struct device *dev,
551 struct device_attribute *attr,
556 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
557 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
560 ret = kstrtobool(buf, &state);
564 mutex_lock(&indio_dev->mlock);
565 if (iio_buffer_is_active(buffer)) {
569 buffer->scan_timestamp = state;
571 mutex_unlock(&indio_dev->mlock);
573 return ret ? ret : len;
576 static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
577 struct iio_buffer *buffer,
578 const struct iio_chan_spec *chan)
580 int ret, attrcount = 0;
582 ret = __iio_add_chan_devattr("index",
584 &iio_show_scan_index,
590 &buffer->buffer_attr_list);
594 ret = __iio_add_chan_devattr("type",
596 &iio_show_fixed_type,
602 &buffer->buffer_attr_list);
606 if (chan->type != IIO_TIMESTAMP)
607 ret = __iio_add_chan_devattr("en",
615 &buffer->buffer_attr_list);
617 ret = __iio_add_chan_devattr("en",
619 &iio_scan_el_ts_show,
620 &iio_scan_el_ts_store,
625 &buffer->buffer_attr_list);
633 static ssize_t length_show(struct device *dev, struct device_attribute *attr,
636 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
638 return sysfs_emit(buf, "%d\n", buffer->length);
641 static ssize_t length_store(struct device *dev, struct device_attribute *attr,
642 const char *buf, size_t len)
644 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
645 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
649 ret = kstrtouint(buf, 10, &val);
653 if (val == buffer->length)
656 mutex_lock(&indio_dev->mlock);
657 if (iio_buffer_is_active(buffer)) {
660 buffer->access->set_length(buffer, val);
665 if (buffer->length && buffer->length < buffer->watermark)
666 buffer->watermark = buffer->length;
668 mutex_unlock(&indio_dev->mlock);
670 return ret ? ret : len;
673 static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
676 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
678 return sysfs_emit(buf, "%d\n", iio_buffer_is_active(buffer));
681 static unsigned int iio_storage_bytes_for_si(struct iio_dev *indio_dev,
682 unsigned int scan_index)
684 const struct iio_chan_spec *ch;
687 ch = iio_find_channel_from_si(indio_dev, scan_index);
688 bytes = ch->scan_type.storagebits / 8;
689 if (ch->scan_type.repeat > 1)
690 bytes *= ch->scan_type.repeat;
694 static unsigned int iio_storage_bytes_for_timestamp(struct iio_dev *indio_dev)
696 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
698 return iio_storage_bytes_for_si(indio_dev,
699 iio_dev_opaque->scan_index_timestamp);
702 static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
703 const unsigned long *mask, bool timestamp)
705 unsigned int bytes = 0;
706 int length, i, largest = 0;
708 /* How much space will the demuxed element take? */
709 for_each_set_bit(i, mask,
710 indio_dev->masklength) {
711 length = iio_storage_bytes_for_si(indio_dev, i);
712 bytes = ALIGN(bytes, length);
714 largest = max(largest, length);
718 length = iio_storage_bytes_for_timestamp(indio_dev);
719 bytes = ALIGN(bytes, length);
721 largest = max(largest, length);
724 bytes = ALIGN(bytes, largest);
728 static void iio_buffer_activate(struct iio_dev *indio_dev,
729 struct iio_buffer *buffer)
731 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
733 iio_buffer_get(buffer);
734 list_add(&buffer->buffer_list, &iio_dev_opaque->buffer_list);
737 static void iio_buffer_deactivate(struct iio_buffer *buffer)
739 list_del_init(&buffer->buffer_list);
740 wake_up_interruptible(&buffer->pollq);
741 iio_buffer_put(buffer);
744 static void iio_buffer_deactivate_all(struct iio_dev *indio_dev)
746 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
747 struct iio_buffer *buffer, *_buffer;
749 list_for_each_entry_safe(buffer, _buffer,
750 &iio_dev_opaque->buffer_list, buffer_list)
751 iio_buffer_deactivate(buffer);
754 static int iio_buffer_enable(struct iio_buffer *buffer,
755 struct iio_dev *indio_dev)
757 if (!buffer->access->enable)
759 return buffer->access->enable(buffer, indio_dev);
762 static int iio_buffer_disable(struct iio_buffer *buffer,
763 struct iio_dev *indio_dev)
765 if (!buffer->access->disable)
767 return buffer->access->disable(buffer, indio_dev);
770 static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
771 struct iio_buffer *buffer)
775 if (!buffer->access->set_bytes_per_datum)
778 bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
779 buffer->scan_timestamp);
781 buffer->access->set_bytes_per_datum(buffer, bytes);
784 static int iio_buffer_request_update(struct iio_dev *indio_dev,
785 struct iio_buffer *buffer)
789 iio_buffer_update_bytes_per_datum(indio_dev, buffer);
790 if (buffer->access->request_update) {
791 ret = buffer->access->request_update(buffer);
793 dev_dbg(&indio_dev->dev,
794 "Buffer not started: buffer parameter update failed (%d)\n",
803 static void iio_free_scan_mask(struct iio_dev *indio_dev,
804 const unsigned long *mask)
806 /* If the mask is dynamically allocated free it, otherwise do nothing */
807 if (!indio_dev->available_scan_masks)
811 struct iio_device_config {
813 unsigned int watermark;
814 const unsigned long *scan_mask;
815 unsigned int scan_bytes;
819 static int iio_verify_update(struct iio_dev *indio_dev,
820 struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer,
821 struct iio_device_config *config)
823 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
824 unsigned long *compound_mask;
825 const unsigned long *scan_mask;
826 bool strict_scanmask = false;
827 struct iio_buffer *buffer;
832 bitmap_empty(insert_buffer->scan_mask, indio_dev->masklength)) {
833 dev_dbg(&indio_dev->dev,
834 "At least one scan element must be enabled first\n");
838 memset(config, 0, sizeof(*config));
839 config->watermark = ~0;
842 * If there is just one buffer and we are removing it there is nothing
845 if (remove_buffer && !insert_buffer &&
846 list_is_singular(&iio_dev_opaque->buffer_list))
849 modes = indio_dev->modes;
851 list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
852 if (buffer == remove_buffer)
854 modes &= buffer->access->modes;
855 config->watermark = min(config->watermark, buffer->watermark);
859 modes &= insert_buffer->access->modes;
860 config->watermark = min(config->watermark,
861 insert_buffer->watermark);
864 /* Definitely possible for devices to support both of these. */
865 if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
866 config->mode = INDIO_BUFFER_TRIGGERED;
867 } else if (modes & INDIO_BUFFER_HARDWARE) {
869 * Keep things simple for now and only allow a single buffer to
870 * be connected in hardware mode.
872 if (insert_buffer && !list_empty(&iio_dev_opaque->buffer_list))
874 config->mode = INDIO_BUFFER_HARDWARE;
875 strict_scanmask = true;
876 } else if (modes & INDIO_BUFFER_SOFTWARE) {
877 config->mode = INDIO_BUFFER_SOFTWARE;
879 /* Can only occur on first buffer */
880 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
881 dev_dbg(&indio_dev->dev, "Buffer not started: no trigger\n");
885 /* What scan mask do we actually have? */
886 compound_mask = bitmap_zalloc(indio_dev->masklength, GFP_KERNEL);
887 if (compound_mask == NULL)
890 scan_timestamp = false;
892 list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
893 if (buffer == remove_buffer)
895 bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
896 indio_dev->masklength);
897 scan_timestamp |= buffer->scan_timestamp;
901 bitmap_or(compound_mask, compound_mask,
902 insert_buffer->scan_mask, indio_dev->masklength);
903 scan_timestamp |= insert_buffer->scan_timestamp;
906 if (indio_dev->available_scan_masks) {
907 scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks,
908 indio_dev->masklength,
911 bitmap_free(compound_mask);
912 if (scan_mask == NULL)
915 scan_mask = compound_mask;
918 config->scan_bytes = iio_compute_scan_bytes(indio_dev,
919 scan_mask, scan_timestamp);
920 config->scan_mask = scan_mask;
921 config->scan_timestamp = scan_timestamp;
927 * struct iio_demux_table - table describing demux memcpy ops
928 * @from: index to copy from
929 * @to: index to copy to
930 * @length: how many bytes to copy
931 * @l: list head used for management
933 struct iio_demux_table {
940 static void iio_buffer_demux_free(struct iio_buffer *buffer)
942 struct iio_demux_table *p, *q;
943 list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
949 static int iio_buffer_add_demux(struct iio_buffer *buffer,
950 struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc,
954 if (*p && (*p)->from + (*p)->length == in_loc &&
955 (*p)->to + (*p)->length == out_loc) {
956 (*p)->length += length;
958 *p = kmalloc(sizeof(**p), GFP_KERNEL);
963 (*p)->length = length;
964 list_add_tail(&(*p)->l, &buffer->demux_list);
970 static int iio_buffer_update_demux(struct iio_dev *indio_dev,
971 struct iio_buffer *buffer)
973 int ret, in_ind = -1, out_ind, length;
974 unsigned int in_loc = 0, out_loc = 0;
975 struct iio_demux_table *p = NULL;
977 /* Clear out any old demux */
978 iio_buffer_demux_free(buffer);
979 kfree(buffer->demux_bounce);
980 buffer->demux_bounce = NULL;
982 /* First work out which scan mode we will actually have */
983 if (bitmap_equal(indio_dev->active_scan_mask,
985 indio_dev->masklength))
988 /* Now we have the two masks, work from least sig and build up sizes */
989 for_each_set_bit(out_ind,
991 indio_dev->masklength) {
992 in_ind = find_next_bit(indio_dev->active_scan_mask,
993 indio_dev->masklength,
995 while (in_ind != out_ind) {
996 length = iio_storage_bytes_for_si(indio_dev, in_ind);
997 /* Make sure we are aligned */
998 in_loc = roundup(in_loc, length) + length;
999 in_ind = find_next_bit(indio_dev->active_scan_mask,
1000 indio_dev->masklength,
1003 length = iio_storage_bytes_for_si(indio_dev, in_ind);
1004 out_loc = roundup(out_loc, length);
1005 in_loc = roundup(in_loc, length);
1006 ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
1008 goto error_clear_mux_table;
1012 /* Relies on scan_timestamp being last */
1013 if (buffer->scan_timestamp) {
1014 length = iio_storage_bytes_for_timestamp(indio_dev);
1015 out_loc = roundup(out_loc, length);
1016 in_loc = roundup(in_loc, length);
1017 ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
1019 goto error_clear_mux_table;
1022 buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
1023 if (buffer->demux_bounce == NULL) {
1025 goto error_clear_mux_table;
1029 error_clear_mux_table:
1030 iio_buffer_demux_free(buffer);
1035 static int iio_update_demux(struct iio_dev *indio_dev)
1037 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1038 struct iio_buffer *buffer;
1041 list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
1042 ret = iio_buffer_update_demux(indio_dev, buffer);
1044 goto error_clear_mux_table;
1048 error_clear_mux_table:
1049 list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list)
1050 iio_buffer_demux_free(buffer);
1055 static int iio_enable_buffers(struct iio_dev *indio_dev,
1056 struct iio_device_config *config)
1058 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1059 struct iio_buffer *buffer, *tmp = NULL;
1062 indio_dev->active_scan_mask = config->scan_mask;
1063 indio_dev->scan_timestamp = config->scan_timestamp;
1064 indio_dev->scan_bytes = config->scan_bytes;
1065 iio_dev_opaque->currentmode = config->mode;
1067 iio_update_demux(indio_dev);
1070 if (indio_dev->setup_ops->preenable) {
1071 ret = indio_dev->setup_ops->preenable(indio_dev);
1073 dev_dbg(&indio_dev->dev,
1074 "Buffer not started: buffer preenable failed (%d)\n", ret);
1075 goto err_undo_config;
1079 if (indio_dev->info->update_scan_mode) {
1080 ret = indio_dev->info
1081 ->update_scan_mode(indio_dev,
1082 indio_dev->active_scan_mask);
1084 dev_dbg(&indio_dev->dev,
1085 "Buffer not started: update scan mode failed (%d)\n",
1087 goto err_run_postdisable;
1091 if (indio_dev->info->hwfifo_set_watermark)
1092 indio_dev->info->hwfifo_set_watermark(indio_dev,
1095 list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
1096 ret = iio_buffer_enable(buffer, indio_dev);
1099 goto err_disable_buffers;
1103 if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
1104 ret = iio_trigger_attach_poll_func(indio_dev->trig,
1105 indio_dev->pollfunc);
1107 goto err_disable_buffers;
1110 if (indio_dev->setup_ops->postenable) {
1111 ret = indio_dev->setup_ops->postenable(indio_dev);
1113 dev_dbg(&indio_dev->dev,
1114 "Buffer not started: postenable failed (%d)\n", ret);
1115 goto err_detach_pollfunc;
1121 err_detach_pollfunc:
1122 if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
1123 iio_trigger_detach_poll_func(indio_dev->trig,
1124 indio_dev->pollfunc);
1126 err_disable_buffers:
1127 buffer = list_prepare_entry(tmp, &iio_dev_opaque->buffer_list, buffer_list);
1128 list_for_each_entry_continue_reverse(buffer, &iio_dev_opaque->buffer_list,
1130 iio_buffer_disable(buffer, indio_dev);
1131 err_run_postdisable:
1132 if (indio_dev->setup_ops->postdisable)
1133 indio_dev->setup_ops->postdisable(indio_dev);
1135 iio_dev_opaque->currentmode = INDIO_DIRECT_MODE;
1136 indio_dev->active_scan_mask = NULL;
1141 static int iio_disable_buffers(struct iio_dev *indio_dev)
1143 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1144 struct iio_buffer *buffer;
1148 /* Wind down existing buffers - iff there are any */
1149 if (list_empty(&iio_dev_opaque->buffer_list))
1153 * If things go wrong at some step in disable we still need to continue
1154 * to perform the other steps, otherwise we leave the device in a
1155 * inconsistent state. We return the error code for the first error we
1159 if (indio_dev->setup_ops->predisable) {
1160 ret2 = indio_dev->setup_ops->predisable(indio_dev);
1165 if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED) {
1166 iio_trigger_detach_poll_func(indio_dev->trig,
1167 indio_dev->pollfunc);
1170 list_for_each_entry(buffer, &iio_dev_opaque->buffer_list, buffer_list) {
1171 ret2 = iio_buffer_disable(buffer, indio_dev);
1176 if (indio_dev->setup_ops->postdisable) {
1177 ret2 = indio_dev->setup_ops->postdisable(indio_dev);
1182 iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask);
1183 indio_dev->active_scan_mask = NULL;
1184 iio_dev_opaque->currentmode = INDIO_DIRECT_MODE;
1189 static int __iio_update_buffers(struct iio_dev *indio_dev,
1190 struct iio_buffer *insert_buffer,
1191 struct iio_buffer *remove_buffer)
1193 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1194 struct iio_device_config new_config;
1197 ret = iio_verify_update(indio_dev, insert_buffer, remove_buffer,
1202 if (insert_buffer) {
1203 ret = iio_buffer_request_update(indio_dev, insert_buffer);
1205 goto err_free_config;
1208 ret = iio_disable_buffers(indio_dev);
1210 goto err_deactivate_all;
1213 iio_buffer_deactivate(remove_buffer);
1215 iio_buffer_activate(indio_dev, insert_buffer);
1217 /* If no buffers in list, we are done */
1218 if (list_empty(&iio_dev_opaque->buffer_list))
1221 ret = iio_enable_buffers(indio_dev, &new_config);
1223 goto err_deactivate_all;
1229 * We've already verified that the config is valid earlier. If things go
1230 * wrong in either enable or disable the most likely reason is an IO
1231 * error from the device. In this case there is no good recovery
1232 * strategy. Just make sure to disable everything and leave the device
1233 * in a sane state. With a bit of luck the device might come back to
1234 * life again later and userspace can try again.
1236 iio_buffer_deactivate_all(indio_dev);
1239 iio_free_scan_mask(indio_dev, new_config.scan_mask);
1243 int iio_update_buffers(struct iio_dev *indio_dev,
1244 struct iio_buffer *insert_buffer,
1245 struct iio_buffer *remove_buffer)
1247 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1250 if (insert_buffer == remove_buffer)
1253 if (insert_buffer &&
1254 (insert_buffer->direction == IIO_BUFFER_DIRECTION_OUT))
1257 mutex_lock(&iio_dev_opaque->info_exist_lock);
1258 mutex_lock(&indio_dev->mlock);
1260 if (insert_buffer && iio_buffer_is_active(insert_buffer))
1261 insert_buffer = NULL;
1263 if (remove_buffer && !iio_buffer_is_active(remove_buffer))
1264 remove_buffer = NULL;
1266 if (!insert_buffer && !remove_buffer) {
1271 if (indio_dev->info == NULL) {
1276 ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
1279 mutex_unlock(&indio_dev->mlock);
1280 mutex_unlock(&iio_dev_opaque->info_exist_lock);
1284 EXPORT_SYMBOL_GPL(iio_update_buffers);
1286 void iio_disable_all_buffers(struct iio_dev *indio_dev)
1288 iio_disable_buffers(indio_dev);
1289 iio_buffer_deactivate_all(indio_dev);
1292 static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
1293 const char *buf, size_t len)
1296 bool requested_state;
1297 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1298 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
1301 ret = kstrtobool(buf, &requested_state);
1305 mutex_lock(&indio_dev->mlock);
1307 /* Find out if it is in the list */
1308 inlist = iio_buffer_is_active(buffer);
1309 /* Already in desired state */
1310 if (inlist == requested_state)
1313 if (requested_state)
1314 ret = __iio_update_buffers(indio_dev, buffer, NULL);
1316 ret = __iio_update_buffers(indio_dev, NULL, buffer);
1319 mutex_unlock(&indio_dev->mlock);
1320 return (ret < 0) ? ret : len;
1323 static ssize_t watermark_show(struct device *dev, struct device_attribute *attr,
1326 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
1328 return sysfs_emit(buf, "%u\n", buffer->watermark);
1331 static ssize_t watermark_store(struct device *dev,
1332 struct device_attribute *attr,
1333 const char *buf, size_t len)
1335 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
1336 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
1340 ret = kstrtouint(buf, 10, &val);
1346 mutex_lock(&indio_dev->mlock);
1348 if (val > buffer->length) {
1353 if (iio_buffer_is_active(buffer)) {
1358 buffer->watermark = val;
1360 mutex_unlock(&indio_dev->mlock);
1362 return ret ? ret : len;
1365 static ssize_t data_available_show(struct device *dev,
1366 struct device_attribute *attr, char *buf)
1368 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
1370 return sysfs_emit(buf, "%zu\n", iio_buffer_data_available(buffer));
1373 static ssize_t direction_show(struct device *dev,
1374 struct device_attribute *attr,
1377 struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
1379 switch (buffer->direction) {
1380 case IIO_BUFFER_DIRECTION_IN:
1381 return sysfs_emit(buf, "in\n");
1382 case IIO_BUFFER_DIRECTION_OUT:
1383 return sysfs_emit(buf, "out\n");
1389 static DEVICE_ATTR_RW(length);
1390 static struct device_attribute dev_attr_length_ro = __ATTR_RO(length);
1391 static DEVICE_ATTR_RW(enable);
1392 static DEVICE_ATTR_RW(watermark);
1393 static struct device_attribute dev_attr_watermark_ro = __ATTR_RO(watermark);
1394 static DEVICE_ATTR_RO(data_available);
1395 static DEVICE_ATTR_RO(direction);
1398 * When adding new attributes here, put the at the end, at least until
1399 * the code that handles the length/length_ro & watermark/watermark_ro
1400 * assignments gets cleaned up. Otherwise these can create some weird
1401 * duplicate attributes errors under some setups.
1403 static struct attribute *iio_buffer_attrs[] = {
1404 &dev_attr_length.attr,
1405 &dev_attr_enable.attr,
1406 &dev_attr_watermark.attr,
1407 &dev_attr_data_available.attr,
1408 &dev_attr_direction.attr,
1411 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
1413 static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer,
1414 struct attribute *attr)
1416 struct device_attribute *dattr = to_dev_attr(attr);
1417 struct iio_dev_attr *iio_attr;
1419 iio_attr = kzalloc(sizeof(*iio_attr), GFP_KERNEL);
1423 iio_attr->buffer = buffer;
1424 memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr));
1425 iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL);
1426 if (!iio_attr->dev_attr.attr.name) {
1431 sysfs_attr_init(&iio_attr->dev_attr.attr);
1433 list_add(&iio_attr->l, &buffer->buffer_attr_list);
1435 return &iio_attr->dev_attr.attr;
1438 static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
1439 struct attribute **buffer_attrs,
1440 int buffer_attrcount,
1441 int scan_el_attrcount)
1443 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1444 struct attribute_group *group;
1445 struct attribute **attrs;
1448 attrs = kcalloc(buffer_attrcount + 1, sizeof(*attrs), GFP_KERNEL);
1452 memcpy(attrs, buffer_attrs, buffer_attrcount * sizeof(*attrs));
1454 group = &iio_dev_opaque->legacy_buffer_group;
1455 group->attrs = attrs;
1456 group->name = "buffer";
1458 ret = iio_device_register_sysfs_group(indio_dev, group);
1460 goto error_free_buffer_attrs;
1462 attrs = kcalloc(scan_el_attrcount + 1, sizeof(*attrs), GFP_KERNEL);
1465 goto error_free_buffer_attrs;
1468 memcpy(attrs, &buffer_attrs[buffer_attrcount],
1469 scan_el_attrcount * sizeof(*attrs));
1471 group = &iio_dev_opaque->legacy_scan_el_group;
1472 group->attrs = attrs;
1473 group->name = "scan_elements";
1475 ret = iio_device_register_sysfs_group(indio_dev, group);
1477 goto error_free_scan_el_attrs;
1481 error_free_scan_el_attrs:
1482 kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
1483 error_free_buffer_attrs:
1484 kfree(iio_dev_opaque->legacy_buffer_group.attrs);
1489 static void iio_buffer_unregister_legacy_sysfs_groups(struct iio_dev *indio_dev)
1491 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1493 kfree(iio_dev_opaque->legacy_buffer_group.attrs);
1494 kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
1497 static int iio_buffer_chrdev_release(struct inode *inode, struct file *filep)
1499 struct iio_dev_buffer_pair *ib = filep->private_data;
1500 struct iio_dev *indio_dev = ib->indio_dev;
1501 struct iio_buffer *buffer = ib->buffer;
1503 wake_up(&buffer->pollq);
1506 clear_bit(IIO_BUSY_BIT_POS, &buffer->flags);
1507 iio_device_put(indio_dev);
1512 static const struct file_operations iio_buffer_chrdev_fileops = {
1513 .owner = THIS_MODULE,
1514 .llseek = noop_llseek,
1515 .read = iio_buffer_read,
1516 .write = iio_buffer_write,
1517 .poll = iio_buffer_poll,
1518 .release = iio_buffer_chrdev_release,
1521 static long iio_device_buffer_getfd(struct iio_dev *indio_dev, unsigned long arg)
1523 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1524 int __user *ival = (int __user *)arg;
1525 struct iio_dev_buffer_pair *ib;
1526 struct iio_buffer *buffer;
1529 if (copy_from_user(&idx, ival, sizeof(idx)))
1532 if (idx >= iio_dev_opaque->attached_buffers_cnt)
1535 iio_device_get(indio_dev);
1537 buffer = iio_dev_opaque->attached_buffers[idx];
1539 if (test_and_set_bit(IIO_BUSY_BIT_POS, &buffer->flags)) {
1541 goto error_iio_dev_put;
1544 ib = kzalloc(sizeof(*ib), GFP_KERNEL);
1547 goto error_clear_busy_bit;
1550 ib->indio_dev = indio_dev;
1551 ib->buffer = buffer;
1553 fd = anon_inode_getfd("iio:buffer", &iio_buffer_chrdev_fileops,
1554 ib, O_RDWR | O_CLOEXEC);
1560 if (copy_to_user(ival, &fd, sizeof(fd))) {
1562 * "Leak" the fd, as there's not much we can do about this
1563 * anyway. 'fd' might have been closed already, as
1564 * anon_inode_getfd() called fd_install() on it, which made
1565 * it reachable by userland.
1567 * Instead of allowing a malicious user to play tricks with
1568 * us, rely on the process exit path to do any necessary
1569 * cleanup, as in releasing the file, if still needed.
1578 error_clear_busy_bit:
1579 clear_bit(IIO_BUSY_BIT_POS, &buffer->flags);
1581 iio_device_put(indio_dev);
1585 static long iio_device_buffer_ioctl(struct iio_dev *indio_dev, struct file *filp,
1586 unsigned int cmd, unsigned long arg)
1589 case IIO_BUFFER_GET_FD_IOCTL:
1590 return iio_device_buffer_getfd(indio_dev, arg);
1592 return IIO_IOCTL_UNHANDLED;
1596 static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
1597 struct iio_dev *indio_dev,
1600 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1601 struct iio_dev_attr *p;
1602 struct attribute **attr;
1603 int ret, i, attrn, scan_el_attrcount, buffer_attrcount;
1604 const struct iio_chan_spec *channels;
1606 buffer_attrcount = 0;
1607 if (buffer->attrs) {
1608 while (buffer->attrs[buffer_attrcount] != NULL)
1612 scan_el_attrcount = 0;
1613 INIT_LIST_HEAD(&buffer->buffer_attr_list);
1614 channels = indio_dev->channels;
1617 for (i = 0; i < indio_dev->num_channels; i++) {
1618 if (channels[i].scan_index < 0)
1621 /* Verify that sample bits fit into storage */
1622 if (channels[i].scan_type.storagebits <
1623 channels[i].scan_type.realbits +
1624 channels[i].scan_type.shift) {
1625 dev_err(&indio_dev->dev,
1626 "Channel %d storagebits (%d) < shifted realbits (%d + %d)\n",
1627 i, channels[i].scan_type.storagebits,
1628 channels[i].scan_type.realbits,
1629 channels[i].scan_type.shift);
1631 goto error_cleanup_dynamic;
1634 ret = iio_buffer_add_channel_sysfs(indio_dev, buffer,
1637 goto error_cleanup_dynamic;
1638 scan_el_attrcount += ret;
1639 if (channels[i].type == IIO_TIMESTAMP)
1640 iio_dev_opaque->scan_index_timestamp =
1641 channels[i].scan_index;
1643 if (indio_dev->masklength && buffer->scan_mask == NULL) {
1644 buffer->scan_mask = bitmap_zalloc(indio_dev->masklength,
1646 if (buffer->scan_mask == NULL) {
1648 goto error_cleanup_dynamic;
1653 attrn = buffer_attrcount + scan_el_attrcount + ARRAY_SIZE(iio_buffer_attrs);
1654 attr = kcalloc(attrn + 1, sizeof(*attr), GFP_KERNEL);
1657 goto error_free_scan_mask;
1660 memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
1661 if (!buffer->access->set_length)
1662 attr[0] = &dev_attr_length_ro.attr;
1664 if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK)
1665 attr[2] = &dev_attr_watermark_ro.attr;
1668 memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
1669 sizeof(struct attribute *) * buffer_attrcount);
1671 buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs);
1672 buffer->buffer_group.attrs = attr;
1674 for (i = 0; i < buffer_attrcount; i++) {
1675 struct attribute *wrapped;
1677 wrapped = iio_buffer_wrap_attr(buffer, attr[i]);
1680 goto error_free_buffer_attrs;
1686 list_for_each_entry(p, &buffer->buffer_attr_list, l)
1687 attr[attrn++] = &p->dev_attr.attr;
1689 buffer->buffer_group.name = kasprintf(GFP_KERNEL, "buffer%d", index);
1690 if (!buffer->buffer_group.name) {
1692 goto error_free_buffer_attrs;
1695 ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);
1697 goto error_free_buffer_attr_group_name;
1699 /* we only need to register the legacy groups for the first buffer */
1703 ret = iio_buffer_register_legacy_sysfs_groups(indio_dev, attr,
1707 goto error_free_buffer_attr_group_name;
1711 error_free_buffer_attr_group_name:
1712 kfree(buffer->buffer_group.name);
1713 error_free_buffer_attrs:
1714 kfree(buffer->buffer_group.attrs);
1715 error_free_scan_mask:
1716 bitmap_free(buffer->scan_mask);
1717 error_cleanup_dynamic:
1718 iio_free_chan_devattr_list(&buffer->buffer_attr_list);
1723 static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer,
1724 struct iio_dev *indio_dev,
1728 iio_buffer_unregister_legacy_sysfs_groups(indio_dev);
1729 bitmap_free(buffer->scan_mask);
1730 kfree(buffer->buffer_group.name);
1731 kfree(buffer->buffer_group.attrs);
1732 iio_free_chan_devattr_list(&buffer->buffer_attr_list);
1735 int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
1737 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1738 const struct iio_chan_spec *channels;
1739 struct iio_buffer *buffer;
1743 channels = indio_dev->channels;
1745 int ml = indio_dev->masklength;
1747 for (i = 0; i < indio_dev->num_channels; i++)
1748 ml = max(ml, channels[i].scan_index + 1);
1749 indio_dev->masklength = ml;
1752 if (!iio_dev_opaque->attached_buffers_cnt)
1755 for (idx = 0; idx < iio_dev_opaque->attached_buffers_cnt; idx++) {
1756 buffer = iio_dev_opaque->attached_buffers[idx];
1757 ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, idx);
1759 goto error_unwind_sysfs_and_mask;
1762 sz = sizeof(*(iio_dev_opaque->buffer_ioctl_handler));
1763 iio_dev_opaque->buffer_ioctl_handler = kzalloc(sz, GFP_KERNEL);
1764 if (!iio_dev_opaque->buffer_ioctl_handler) {
1766 goto error_unwind_sysfs_and_mask;
1769 iio_dev_opaque->buffer_ioctl_handler->ioctl = iio_device_buffer_ioctl;
1770 iio_device_ioctl_handler_register(indio_dev,
1771 iio_dev_opaque->buffer_ioctl_handler);
1775 error_unwind_sysfs_and_mask:
1777 buffer = iio_dev_opaque->attached_buffers[idx];
1778 __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, idx);
1783 void iio_buffers_free_sysfs_and_mask(struct iio_dev *indio_dev)
1785 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1786 struct iio_buffer *buffer;
1789 if (!iio_dev_opaque->attached_buffers_cnt)
1792 iio_device_ioctl_handler_unregister(iio_dev_opaque->buffer_ioctl_handler);
1793 kfree(iio_dev_opaque->buffer_ioctl_handler);
1795 for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) {
1796 buffer = iio_dev_opaque->attached_buffers[i];
1797 __iio_buffer_free_sysfs_and_mask(buffer, indio_dev, i);
1802 * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
1803 * @indio_dev: the iio device
1804 * @mask: scan mask to be checked
1806 * Return true if exactly one bit is set in the scan mask, false otherwise. It
1807 * can be used for devices where only one channel can be active for sampling at
1810 bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
1811 const unsigned long *mask)
1813 return bitmap_weight(mask, indio_dev->masklength) == 1;
1815 EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
1817 static const void *iio_demux(struct iio_buffer *buffer,
1820 struct iio_demux_table *t;
1822 if (list_empty(&buffer->demux_list))
1824 list_for_each_entry(t, &buffer->demux_list, l)
1825 memcpy(buffer->demux_bounce + t->to,
1826 datain + t->from, t->length);
1828 return buffer->demux_bounce;
1831 static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
1833 const void *dataout = iio_demux(buffer, data);
1836 ret = buffer->access->store_to(buffer, dataout);
1841 * We can't just test for watermark to decide if we wake the poll queue
1842 * because read may request less samples than the watermark.
1844 wake_up_interruptible_poll(&buffer->pollq, EPOLLIN | EPOLLRDNORM);
1849 * iio_push_to_buffers() - push to a registered buffer.
1850 * @indio_dev: iio_dev structure for device.
1853 int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
1855 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1857 struct iio_buffer *buf;
1859 list_for_each_entry(buf, &iio_dev_opaque->buffer_list, buffer_list) {
1860 ret = iio_push_to_buffer(buf, data);
1867 EXPORT_SYMBOL_GPL(iio_push_to_buffers);
1870 * iio_push_to_buffers_with_ts_unaligned() - push to registered buffer,
1871 * no alignment or space requirements.
1872 * @indio_dev: iio_dev structure for device.
1873 * @data: channel data excluding the timestamp.
1874 * @data_sz: size of data.
1875 * @timestamp: timestamp for the sample data.
1877 * This special variant of iio_push_to_buffers_with_timestamp() does
1878 * not require space for the timestamp, or 8 byte alignment of data.
1879 * It does however require an allocation on first call and additional
1880 * copies on all calls, so should be avoided if possible.
1882 int iio_push_to_buffers_with_ts_unaligned(struct iio_dev *indio_dev,
1887 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1890 * Conservative estimate - we can always safely copy the minimum
1891 * of either the data provided or the length of the destination buffer.
1892 * This relaxed limit allows the calling drivers to be lax about
1893 * tracking the size of the data they are pushing, at the cost of
1894 * unnecessary copying of padding.
1896 data_sz = min_t(size_t, indio_dev->scan_bytes, data_sz);
1897 if (iio_dev_opaque->bounce_buffer_size != indio_dev->scan_bytes) {
1900 bb = devm_krealloc(&indio_dev->dev,
1901 iio_dev_opaque->bounce_buffer,
1902 indio_dev->scan_bytes, GFP_KERNEL);
1905 iio_dev_opaque->bounce_buffer = bb;
1906 iio_dev_opaque->bounce_buffer_size = indio_dev->scan_bytes;
1908 memcpy(iio_dev_opaque->bounce_buffer, data, data_sz);
1909 return iio_push_to_buffers_with_timestamp(indio_dev,
1910 iio_dev_opaque->bounce_buffer,
1913 EXPORT_SYMBOL_GPL(iio_push_to_buffers_with_ts_unaligned);
1916 * iio_buffer_release() - Free a buffer's resources
1917 * @ref: Pointer to the kref embedded in the iio_buffer struct
1919 * This function is called when the last reference to the buffer has been
1920 * dropped. It will typically free all resources allocated by the buffer. Do not
1921 * call this function manually, always use iio_buffer_put() when done using a
1924 static void iio_buffer_release(struct kref *ref)
1926 struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
1928 buffer->access->release(buffer);
1932 * iio_buffer_get() - Grab a reference to the buffer
1933 * @buffer: The buffer to grab a reference for, may be NULL
1935 * Returns the pointer to the buffer that was passed into the function.
1937 struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
1940 kref_get(&buffer->ref);
1944 EXPORT_SYMBOL_GPL(iio_buffer_get);
1947 * iio_buffer_put() - Release the reference to the buffer
1948 * @buffer: The buffer to release the reference for, may be NULL
1950 void iio_buffer_put(struct iio_buffer *buffer)
1953 kref_put(&buffer->ref, iio_buffer_release);
1955 EXPORT_SYMBOL_GPL(iio_buffer_put);
1958 * iio_device_attach_buffer - Attach a buffer to a IIO device
1959 * @indio_dev: The device the buffer should be attached to
1960 * @buffer: The buffer to attach to the device
1962 * Return 0 if successful, negative if error.
1964 * This function attaches a buffer to a IIO device. The buffer stays attached to
1965 * the device until the device is freed. For legacy reasons, the first attached
1966 * buffer will also be assigned to 'indio_dev->buffer'.
1967 * The array allocated here, will be free'd via the iio_device_detach_buffers()
1968 * call which is handled by the iio_device_free().
1970 int iio_device_attach_buffer(struct iio_dev *indio_dev,
1971 struct iio_buffer *buffer)
1973 struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
1974 struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers;
1975 unsigned int cnt = iio_dev_opaque->attached_buffers_cnt;
1979 new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL);
1982 iio_dev_opaque->attached_buffers = new;
1984 buffer = iio_buffer_get(buffer);
1986 /* first buffer is legacy; attach it to the IIO device directly */
1987 if (!indio_dev->buffer)
1988 indio_dev->buffer = buffer;
1990 iio_dev_opaque->attached_buffers[cnt - 1] = buffer;
1991 iio_dev_opaque->attached_buffers_cnt = cnt;
1995 EXPORT_SYMBOL_GPL(iio_device_attach_buffer);