1 /* The industrial I/O core
3 * Copyright (c) 2008 Jonathan Cameron
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.
9 * Handling of buffer allocation / resizing.
12 * Things to look at here.
13 * - Better memory allocation techniques?
14 * - Alternative access techniques?
16 #include <linux/kernel.h>
17 #include <linux/export.h>
18 #include <linux/device.h>
20 #include <linux/cdev.h>
21 #include <linux/slab.h>
22 #include <linux/poll.h>
23 #include <linux/sched.h>
25 #include <linux/iio/iio.h>
27 #include <linux/iio/sysfs.h>
28 #include <linux/iio/buffer.h>
30 static const char * const iio_endian_prefix[] = {
35 static bool iio_buffer_is_active(struct iio_buffer *buf)
37 return !list_empty(&buf->buffer_list);
40 static bool iio_buffer_data_available(struct iio_buffer *buf)
42 if (buf->access->data_available)
43 return buf->access->data_available(buf);
45 return buf->stufftoread;
49 * iio_buffer_read_first_n_outer() - chrdev read for buffer access
51 * This function relies on all buffer implementations having an
52 * iio_buffer as their first element.
54 ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
55 size_t n, loff_t *f_ps)
57 struct iio_dev *indio_dev = filp->private_data;
58 struct iio_buffer *rb = indio_dev->buffer;
64 if (!rb || !rb->access->read_first_n)
68 if (!iio_buffer_data_available(rb)) {
69 if (filp->f_flags & O_NONBLOCK)
72 ret = wait_event_interruptible(rb->pollq,
73 iio_buffer_data_available(rb) ||
74 indio_dev->info == NULL);
77 if (indio_dev->info == NULL)
81 ret = rb->access->read_first_n(rb, n, buf);
82 if (ret == 0 && (filp->f_flags & O_NONBLOCK))
90 * iio_buffer_poll() - poll the buffer to find out if it has data
92 unsigned int iio_buffer_poll(struct file *filp,
93 struct poll_table_struct *wait)
95 struct iio_dev *indio_dev = filp->private_data;
96 struct iio_buffer *rb = indio_dev->buffer;
101 poll_wait(filp, &rb->pollq, wait);
102 if (iio_buffer_data_available(rb))
103 return POLLIN | POLLRDNORM;
104 /* need a way of knowing if there may be enough data... */
109 * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
110 * @indio_dev: The IIO device
112 * Wakes up the event waitqueue used for poll(). Should usually
113 * be called when the device is unregistered.
115 void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
117 if (!indio_dev->buffer)
120 wake_up(&indio_dev->buffer->pollq);
123 void iio_buffer_init(struct iio_buffer *buffer)
125 INIT_LIST_HEAD(&buffer->demux_list);
126 INIT_LIST_HEAD(&buffer->buffer_list);
127 init_waitqueue_head(&buffer->pollq);
128 kref_init(&buffer->ref);
130 EXPORT_SYMBOL(iio_buffer_init);
132 static ssize_t iio_show_scan_index(struct device *dev,
133 struct device_attribute *attr,
136 return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
139 static ssize_t iio_show_fixed_type(struct device *dev,
140 struct device_attribute *attr,
143 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
144 u8 type = this_attr->c->scan_type.endianness;
146 if (type == IIO_CPU) {
147 #ifdef __LITTLE_ENDIAN
153 if (this_attr->c->scan_type.repeat > 1)
154 return sprintf(buf, "%s:%c%d/%dX%d>>%u\n",
155 iio_endian_prefix[type],
156 this_attr->c->scan_type.sign,
157 this_attr->c->scan_type.realbits,
158 this_attr->c->scan_type.storagebits,
159 this_attr->c->scan_type.repeat,
160 this_attr->c->scan_type.shift);
162 return sprintf(buf, "%s:%c%d/%d>>%u\n",
163 iio_endian_prefix[type],
164 this_attr->c->scan_type.sign,
165 this_attr->c->scan_type.realbits,
166 this_attr->c->scan_type.storagebits,
167 this_attr->c->scan_type.shift);
170 static ssize_t iio_scan_el_show(struct device *dev,
171 struct device_attribute *attr,
175 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
177 /* Ensure ret is 0 or 1. */
178 ret = !!test_bit(to_iio_dev_attr(attr)->address,
179 indio_dev->buffer->scan_mask);
181 return sprintf(buf, "%d\n", ret);
184 static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
186 clear_bit(bit, buffer->scan_mask);
190 static ssize_t iio_scan_el_store(struct device *dev,
191 struct device_attribute *attr,
197 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
198 struct iio_buffer *buffer = indio_dev->buffer;
199 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
201 ret = strtobool(buf, &state);
204 mutex_lock(&indio_dev->mlock);
205 if (iio_buffer_is_active(indio_dev->buffer)) {
209 ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
213 ret = iio_scan_mask_clear(buffer, this_attr->address);
216 } else if (state && !ret) {
217 ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
223 mutex_unlock(&indio_dev->mlock);
225 return ret < 0 ? ret : len;
229 static ssize_t iio_scan_el_ts_show(struct device *dev,
230 struct device_attribute *attr,
233 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
234 return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
237 static ssize_t iio_scan_el_ts_store(struct device *dev,
238 struct device_attribute *attr,
243 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
246 ret = strtobool(buf, &state);
250 mutex_lock(&indio_dev->mlock);
251 if (iio_buffer_is_active(indio_dev->buffer)) {
255 indio_dev->buffer->scan_timestamp = state;
257 mutex_unlock(&indio_dev->mlock);
259 return ret ? ret : len;
262 static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
263 const struct iio_chan_spec *chan)
265 int ret, attrcount = 0;
266 struct iio_buffer *buffer = indio_dev->buffer;
268 ret = __iio_add_chan_devattr("index",
270 &iio_show_scan_index,
275 &buffer->scan_el_dev_attr_list);
279 ret = __iio_add_chan_devattr("type",
281 &iio_show_fixed_type,
286 &buffer->scan_el_dev_attr_list);
290 if (chan->type != IIO_TIMESTAMP)
291 ret = __iio_add_chan_devattr("en",
298 &buffer->scan_el_dev_attr_list);
300 ret = __iio_add_chan_devattr("en",
302 &iio_scan_el_ts_show,
303 &iio_scan_el_ts_store,
307 &buffer->scan_el_dev_attr_list);
315 static const char * const iio_scan_elements_group_name = "scan_elements";
317 int iio_buffer_register(struct iio_dev *indio_dev,
318 const struct iio_chan_spec *channels,
321 struct iio_dev_attr *p;
322 struct attribute **attr;
323 struct iio_buffer *buffer = indio_dev->buffer;
324 int ret, i, attrn, attrcount, attrcount_orig = 0;
327 indio_dev->groups[indio_dev->groupcounter++] = buffer->attrs;
329 if (buffer->scan_el_attrs != NULL) {
330 attr = buffer->scan_el_attrs->attrs;
331 while (*attr++ != NULL)
334 attrcount = attrcount_orig;
335 INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
338 for (i = 0; i < num_channels; i++) {
339 if (channels[i].scan_index < 0)
342 /* Establish necessary mask length */
343 if (channels[i].scan_index >
344 (int)indio_dev->masklength - 1)
345 indio_dev->masklength
346 = channels[i].scan_index + 1;
348 ret = iio_buffer_add_channel_sysfs(indio_dev,
351 goto error_cleanup_dynamic;
353 if (channels[i].type == IIO_TIMESTAMP)
354 indio_dev->scan_index_timestamp =
355 channels[i].scan_index;
357 if (indio_dev->masklength && buffer->scan_mask == NULL) {
358 buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
359 sizeof(*buffer->scan_mask),
361 if (buffer->scan_mask == NULL) {
363 goto error_cleanup_dynamic;
368 buffer->scan_el_group.name = iio_scan_elements_group_name;
370 buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
371 sizeof(buffer->scan_el_group.attrs[0]),
373 if (buffer->scan_el_group.attrs == NULL) {
375 goto error_free_scan_mask;
377 if (buffer->scan_el_attrs)
378 memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
379 sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
380 attrn = attrcount_orig;
382 list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
383 buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
384 indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
388 error_free_scan_mask:
389 kfree(buffer->scan_mask);
390 error_cleanup_dynamic:
391 iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
395 EXPORT_SYMBOL(iio_buffer_register);
397 void iio_buffer_unregister(struct iio_dev *indio_dev)
399 kfree(indio_dev->buffer->scan_mask);
400 kfree(indio_dev->buffer->scan_el_group.attrs);
401 iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
403 EXPORT_SYMBOL(iio_buffer_unregister);
405 ssize_t iio_buffer_read_length(struct device *dev,
406 struct device_attribute *attr,
409 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
410 struct iio_buffer *buffer = indio_dev->buffer;
412 if (buffer->access->get_length)
413 return sprintf(buf, "%d\n",
414 buffer->access->get_length(buffer));
418 EXPORT_SYMBOL(iio_buffer_read_length);
420 ssize_t iio_buffer_write_length(struct device *dev,
421 struct device_attribute *attr,
425 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
426 struct iio_buffer *buffer = indio_dev->buffer;
430 ret = kstrtouint(buf, 10, &val);
434 if (buffer->access->get_length)
435 if (val == buffer->access->get_length(buffer))
438 mutex_lock(&indio_dev->mlock);
439 if (iio_buffer_is_active(indio_dev->buffer)) {
442 if (buffer->access->set_length)
443 buffer->access->set_length(buffer, val);
446 mutex_unlock(&indio_dev->mlock);
448 return ret ? ret : len;
450 EXPORT_SYMBOL(iio_buffer_write_length);
452 ssize_t iio_buffer_show_enable(struct device *dev,
453 struct device_attribute *attr,
456 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
457 return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
459 EXPORT_SYMBOL(iio_buffer_show_enable);
461 /* Note NULL used as error indicator as it doesn't make sense. */
462 static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
463 unsigned int masklength,
464 const unsigned long *mask)
466 if (bitmap_empty(mask, masklength))
469 if (bitmap_subset(mask, av_masks, masklength))
471 av_masks += BITS_TO_LONGS(masklength);
476 static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
477 const unsigned long *mask, bool timestamp)
479 const struct iio_chan_spec *ch;
483 /* How much space will the demuxed element take? */
484 for_each_set_bit(i, mask,
485 indio_dev->masklength) {
486 ch = iio_find_channel_from_si(indio_dev, i);
487 if (ch->scan_type.repeat > 1)
488 length = ch->scan_type.storagebits / 8 *
489 ch->scan_type.repeat;
491 length = ch->scan_type.storagebits / 8;
492 bytes = ALIGN(bytes, length);
496 ch = iio_find_channel_from_si(indio_dev,
497 indio_dev->scan_index_timestamp);
498 if (ch->scan_type.repeat > 1)
499 length = ch->scan_type.storagebits / 8 *
500 ch->scan_type.repeat;
502 length = ch->scan_type.storagebits / 8;
503 bytes = ALIGN(bytes, length);
509 static void iio_buffer_activate(struct iio_dev *indio_dev,
510 struct iio_buffer *buffer)
512 iio_buffer_get(buffer);
513 list_add(&buffer->buffer_list, &indio_dev->buffer_list);
516 static void iio_buffer_deactivate(struct iio_buffer *buffer)
518 list_del_init(&buffer->buffer_list);
519 iio_buffer_put(buffer);
522 void iio_disable_all_buffers(struct iio_dev *indio_dev)
524 struct iio_buffer *buffer, *_buffer;
526 if (list_empty(&indio_dev->buffer_list))
529 if (indio_dev->setup_ops->predisable)
530 indio_dev->setup_ops->predisable(indio_dev);
532 list_for_each_entry_safe(buffer, _buffer,
533 &indio_dev->buffer_list, buffer_list)
534 iio_buffer_deactivate(buffer);
536 indio_dev->currentmode = INDIO_DIRECT_MODE;
537 if (indio_dev->setup_ops->postdisable)
538 indio_dev->setup_ops->postdisable(indio_dev);
540 if (indio_dev->available_scan_masks == NULL)
541 kfree(indio_dev->active_scan_mask);
544 static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
545 struct iio_buffer *buffer)
549 if (!buffer->access->set_bytes_per_datum)
552 bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
553 buffer->scan_timestamp);
555 buffer->access->set_bytes_per_datum(buffer, bytes);
558 static int __iio_update_buffers(struct iio_dev *indio_dev,
559 struct iio_buffer *insert_buffer,
560 struct iio_buffer *remove_buffer)
564 struct iio_buffer *buffer;
565 unsigned long *compound_mask;
566 const unsigned long *old_mask;
568 /* Wind down existing buffers - iff there are any */
569 if (!list_empty(&indio_dev->buffer_list)) {
570 if (indio_dev->setup_ops->predisable) {
571 ret = indio_dev->setup_ops->predisable(indio_dev);
575 indio_dev->currentmode = INDIO_DIRECT_MODE;
576 if (indio_dev->setup_ops->postdisable) {
577 ret = indio_dev->setup_ops->postdisable(indio_dev);
582 /* Keep a copy of current setup to allow roll back */
583 old_mask = indio_dev->active_scan_mask;
584 if (!indio_dev->available_scan_masks)
585 indio_dev->active_scan_mask = NULL;
588 iio_buffer_deactivate(remove_buffer);
590 iio_buffer_activate(indio_dev, insert_buffer);
592 /* If no buffers in list, we are done */
593 if (list_empty(&indio_dev->buffer_list)) {
594 indio_dev->currentmode = INDIO_DIRECT_MODE;
595 if (indio_dev->available_scan_masks == NULL)
600 /* What scan mask do we actually have? */
601 compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
602 sizeof(long), GFP_KERNEL);
603 if (compound_mask == NULL) {
604 if (indio_dev->available_scan_masks == NULL)
608 indio_dev->scan_timestamp = 0;
610 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
611 bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
612 indio_dev->masklength);
613 indio_dev->scan_timestamp |= buffer->scan_timestamp;
615 if (indio_dev->available_scan_masks) {
616 indio_dev->active_scan_mask =
617 iio_scan_mask_match(indio_dev->available_scan_masks,
618 indio_dev->masklength,
620 if (indio_dev->active_scan_mask == NULL) {
623 * Note can only occur when adding a buffer.
625 iio_buffer_deactivate(insert_buffer);
627 indio_dev->active_scan_mask = old_mask;
631 kfree(compound_mask);
637 indio_dev->active_scan_mask = compound_mask;
640 iio_update_demux(indio_dev);
643 if (indio_dev->setup_ops->preenable) {
644 ret = indio_dev->setup_ops->preenable(indio_dev);
647 "Buffer not started: buffer preenable failed (%d)\n", ret);
648 goto error_remove_inserted;
651 indio_dev->scan_bytes =
652 iio_compute_scan_bytes(indio_dev,
653 indio_dev->active_scan_mask,
654 indio_dev->scan_timestamp);
655 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
656 iio_buffer_update_bytes_per_datum(indio_dev, buffer);
657 if (buffer->access->request_update) {
658 ret = buffer->access->request_update(buffer);
661 "Buffer not started: buffer parameter update failed (%d)\n", ret);
662 goto error_run_postdisable;
666 if (indio_dev->info->update_scan_mode) {
667 ret = indio_dev->info
668 ->update_scan_mode(indio_dev,
669 indio_dev->active_scan_mask);
671 printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret);
672 goto error_run_postdisable;
675 /* Definitely possible for devices to support both of these. */
676 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) {
677 if (!indio_dev->trig) {
678 printk(KERN_INFO "Buffer not started: no trigger\n");
680 /* Can only occur on first buffer */
681 goto error_run_postdisable;
683 indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
684 } else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) {
685 indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
686 } else { /* Should never be reached */
688 goto error_run_postdisable;
691 if (indio_dev->setup_ops->postenable) {
692 ret = indio_dev->setup_ops->postenable(indio_dev);
695 "Buffer not started: postenable failed (%d)\n", ret);
696 indio_dev->currentmode = INDIO_DIRECT_MODE;
697 if (indio_dev->setup_ops->postdisable)
698 indio_dev->setup_ops->postdisable(indio_dev);
699 goto error_disable_all_buffers;
703 if (indio_dev->available_scan_masks)
704 kfree(compound_mask);
710 error_disable_all_buffers:
711 indio_dev->currentmode = INDIO_DIRECT_MODE;
712 error_run_postdisable:
713 if (indio_dev->setup_ops->postdisable)
714 indio_dev->setup_ops->postdisable(indio_dev);
715 error_remove_inserted:
717 iio_buffer_deactivate(insert_buffer);
718 indio_dev->active_scan_mask = old_mask;
719 kfree(compound_mask);
723 int iio_update_buffers(struct iio_dev *indio_dev,
724 struct iio_buffer *insert_buffer,
725 struct iio_buffer *remove_buffer)
729 if (insert_buffer == remove_buffer)
732 mutex_lock(&indio_dev->info_exist_lock);
733 mutex_lock(&indio_dev->mlock);
735 if (insert_buffer && iio_buffer_is_active(insert_buffer))
736 insert_buffer = NULL;
738 if (remove_buffer && !iio_buffer_is_active(remove_buffer))
739 remove_buffer = NULL;
741 if (!insert_buffer && !remove_buffer) {
746 if (indio_dev->info == NULL) {
751 ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
754 mutex_unlock(&indio_dev->mlock);
755 mutex_unlock(&indio_dev->info_exist_lock);
759 EXPORT_SYMBOL_GPL(iio_update_buffers);
761 ssize_t iio_buffer_store_enable(struct device *dev,
762 struct device_attribute *attr,
767 bool requested_state;
768 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
771 ret = strtobool(buf, &requested_state);
775 mutex_lock(&indio_dev->mlock);
777 /* Find out if it is in the list */
778 inlist = iio_buffer_is_active(indio_dev->buffer);
779 /* Already in desired state */
780 if (inlist == requested_state)
784 ret = __iio_update_buffers(indio_dev,
785 indio_dev->buffer, NULL);
787 ret = __iio_update_buffers(indio_dev,
788 NULL, indio_dev->buffer);
793 mutex_unlock(&indio_dev->mlock);
794 return (ret < 0) ? ret : len;
796 EXPORT_SYMBOL(iio_buffer_store_enable);
799 * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
800 * @indio_dev: the iio device
801 * @mask: scan mask to be checked
803 * Return true if exactly one bit is set in the scan mask, false otherwise. It
804 * can be used for devices where only one channel can be active for sampling at
807 bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
808 const unsigned long *mask)
810 return bitmap_weight(mask, indio_dev->masklength) == 1;
812 EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
814 static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
815 const unsigned long *mask)
817 if (!indio_dev->setup_ops->validate_scan_mask)
820 return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
824 * iio_scan_mask_set() - set particular bit in the scan mask
825 * @indio_dev: the iio device
826 * @buffer: the buffer whose scan mask we are interested in
827 * @bit: the bit to be set.
829 * Note that at this point we have no way of knowing what other
830 * buffers might request, hence this code only verifies that the
831 * individual buffers request is plausible.
833 int iio_scan_mask_set(struct iio_dev *indio_dev,
834 struct iio_buffer *buffer, int bit)
836 const unsigned long *mask;
837 unsigned long *trialmask;
839 trialmask = kmalloc(sizeof(*trialmask)*
840 BITS_TO_LONGS(indio_dev->masklength),
843 if (trialmask == NULL)
845 if (!indio_dev->masklength) {
846 WARN_ON("Trying to set scanmask prior to registering buffer\n");
847 goto err_invalid_mask;
849 bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
850 set_bit(bit, trialmask);
852 if (!iio_validate_scan_mask(indio_dev, trialmask))
853 goto err_invalid_mask;
855 if (indio_dev->available_scan_masks) {
856 mask = iio_scan_mask_match(indio_dev->available_scan_masks,
857 indio_dev->masklength,
860 goto err_invalid_mask;
862 bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
872 EXPORT_SYMBOL_GPL(iio_scan_mask_set);
874 int iio_scan_mask_query(struct iio_dev *indio_dev,
875 struct iio_buffer *buffer, int bit)
877 if (bit > indio_dev->masklength)
880 if (!buffer->scan_mask)
883 /* Ensure return value is 0 or 1. */
884 return !!test_bit(bit, buffer->scan_mask);
886 EXPORT_SYMBOL_GPL(iio_scan_mask_query);
889 * struct iio_demux_table() - table describing demux memcpy ops
890 * @from: index to copy from
891 * @to: index to copy to
892 * @length: how many bytes to copy
893 * @l: list head used for management
895 struct iio_demux_table {
902 static const void *iio_demux(struct iio_buffer *buffer,
905 struct iio_demux_table *t;
907 if (list_empty(&buffer->demux_list))
909 list_for_each_entry(t, &buffer->demux_list, l)
910 memcpy(buffer->demux_bounce + t->to,
911 datain + t->from, t->length);
913 return buffer->demux_bounce;
916 static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
918 const void *dataout = iio_demux(buffer, data);
920 return buffer->access->store_to(buffer, dataout);
923 static void iio_buffer_demux_free(struct iio_buffer *buffer)
925 struct iio_demux_table *p, *q;
926 list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
933 int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
936 struct iio_buffer *buf;
938 list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) {
939 ret = iio_push_to_buffer(buf, data);
946 EXPORT_SYMBOL_GPL(iio_push_to_buffers);
948 static int iio_buffer_update_demux(struct iio_dev *indio_dev,
949 struct iio_buffer *buffer)
951 const struct iio_chan_spec *ch;
952 int ret, in_ind = -1, out_ind, length;
953 unsigned in_loc = 0, out_loc = 0;
954 struct iio_demux_table *p;
956 /* Clear out any old demux */
957 iio_buffer_demux_free(buffer);
958 kfree(buffer->demux_bounce);
959 buffer->demux_bounce = NULL;
961 /* First work out which scan mode we will actually have */
962 if (bitmap_equal(indio_dev->active_scan_mask,
964 indio_dev->masklength))
967 /* Now we have the two masks, work from least sig and build up sizes */
968 for_each_set_bit(out_ind,
969 indio_dev->active_scan_mask,
970 indio_dev->masklength) {
971 in_ind = find_next_bit(indio_dev->active_scan_mask,
972 indio_dev->masklength,
974 while (in_ind != out_ind) {
975 in_ind = find_next_bit(indio_dev->active_scan_mask,
976 indio_dev->masklength,
978 ch = iio_find_channel_from_si(indio_dev, in_ind);
979 if (ch->scan_type.repeat > 1)
980 length = ch->scan_type.storagebits / 8 *
981 ch->scan_type.repeat;
983 length = ch->scan_type.storagebits / 8;
984 /* Make sure we are aligned */
987 in_loc += length - in_loc % length;
989 p = kmalloc(sizeof(*p), GFP_KERNEL);
992 goto error_clear_mux_table;
994 ch = iio_find_channel_from_si(indio_dev, in_ind);
995 if (ch->scan_type.repeat > 1)
996 length = ch->scan_type.storagebits / 8 *
997 ch->scan_type.repeat;
999 length = ch->scan_type.storagebits / 8;
1000 if (out_loc % length)
1001 out_loc += length - out_loc % length;
1002 if (in_loc % length)
1003 in_loc += length - in_loc % length;
1007 list_add_tail(&p->l, &buffer->demux_list);
1011 /* Relies on scan_timestamp being last */
1012 if (buffer->scan_timestamp) {
1013 p = kmalloc(sizeof(*p), GFP_KERNEL);
1016 goto error_clear_mux_table;
1018 ch = iio_find_channel_from_si(indio_dev,
1019 indio_dev->scan_index_timestamp);
1020 if (ch->scan_type.repeat > 1)
1021 length = ch->scan_type.storagebits / 8 *
1022 ch->scan_type.repeat;
1024 length = ch->scan_type.storagebits / 8;
1025 if (out_loc % length)
1026 out_loc += length - out_loc % length;
1027 if (in_loc % length)
1028 in_loc += length - in_loc % length;
1032 list_add_tail(&p->l, &buffer->demux_list);
1036 buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
1037 if (buffer->demux_bounce == NULL) {
1039 goto error_clear_mux_table;
1043 error_clear_mux_table:
1044 iio_buffer_demux_free(buffer);
1049 int iio_update_demux(struct iio_dev *indio_dev)
1051 struct iio_buffer *buffer;
1054 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
1055 ret = iio_buffer_update_demux(indio_dev, buffer);
1057 goto error_clear_mux_table;
1061 error_clear_mux_table:
1062 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
1063 iio_buffer_demux_free(buffer);
1067 EXPORT_SYMBOL_GPL(iio_update_demux);
1070 * iio_buffer_release() - Free a buffer's resources
1071 * @ref: Pointer to the kref embedded in the iio_buffer struct
1073 * This function is called when the last reference to the buffer has been
1074 * dropped. It will typically free all resources allocated by the buffer. Do not
1075 * call this function manually, always use iio_buffer_put() when done using a
1078 static void iio_buffer_release(struct kref *ref)
1080 struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
1082 buffer->access->release(buffer);
1086 * iio_buffer_get() - Grab a reference to the buffer
1087 * @buffer: The buffer to grab a reference for, may be NULL
1089 * Returns the pointer to the buffer that was passed into the function.
1091 struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
1094 kref_get(&buffer->ref);
1098 EXPORT_SYMBOL_GPL(iio_buffer_get);
1101 * iio_buffer_put() - Release the reference to the buffer
1102 * @buffer: The buffer to release the reference for, may be NULL
1104 void iio_buffer_put(struct iio_buffer *buffer)
1107 kref_put(&buffer->ref, iio_buffer_release);
1109 EXPORT_SYMBOL_GPL(iio_buffer_put);