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 return sprintf(buf, "%s:%c%d/%d>>%u\n",
154 iio_endian_prefix[type],
155 this_attr->c->scan_type.sign,
156 this_attr->c->scan_type.realbits,
157 this_attr->c->scan_type.storagebits,
158 this_attr->c->scan_type.shift);
161 static ssize_t iio_scan_el_show(struct device *dev,
162 struct device_attribute *attr,
166 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
168 ret = test_bit(to_iio_dev_attr(attr)->address,
169 indio_dev->buffer->scan_mask);
171 return sprintf(buf, "%d\n", ret);
174 static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
176 clear_bit(bit, buffer->scan_mask);
180 static ssize_t iio_scan_el_store(struct device *dev,
181 struct device_attribute *attr,
187 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
188 struct iio_buffer *buffer = indio_dev->buffer;
189 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
191 ret = strtobool(buf, &state);
194 mutex_lock(&indio_dev->mlock);
195 if (iio_buffer_is_active(indio_dev->buffer)) {
199 ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
203 ret = iio_scan_mask_clear(buffer, this_attr->address);
206 } else if (state && !ret) {
207 ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
213 mutex_unlock(&indio_dev->mlock);
215 return ret < 0 ? ret : len;
219 static ssize_t iio_scan_el_ts_show(struct device *dev,
220 struct device_attribute *attr,
223 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
224 return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
227 static ssize_t iio_scan_el_ts_store(struct device *dev,
228 struct device_attribute *attr,
233 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
236 ret = strtobool(buf, &state);
240 mutex_lock(&indio_dev->mlock);
241 if (iio_buffer_is_active(indio_dev->buffer)) {
245 indio_dev->buffer->scan_timestamp = state;
247 mutex_unlock(&indio_dev->mlock);
249 return ret ? ret : len;
252 static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
253 const struct iio_chan_spec *chan)
255 int ret, attrcount = 0;
256 struct iio_buffer *buffer = indio_dev->buffer;
258 ret = __iio_add_chan_devattr("index",
260 &iio_show_scan_index,
265 &buffer->scan_el_dev_attr_list);
269 ret = __iio_add_chan_devattr("type",
271 &iio_show_fixed_type,
276 &buffer->scan_el_dev_attr_list);
280 if (chan->type != IIO_TIMESTAMP)
281 ret = __iio_add_chan_devattr("en",
288 &buffer->scan_el_dev_attr_list);
290 ret = __iio_add_chan_devattr("en",
292 &iio_scan_el_ts_show,
293 &iio_scan_el_ts_store,
297 &buffer->scan_el_dev_attr_list);
305 static const char * const iio_scan_elements_group_name = "scan_elements";
307 int iio_buffer_register(struct iio_dev *indio_dev,
308 const struct iio_chan_spec *channels,
311 struct iio_dev_attr *p;
312 struct attribute **attr;
313 struct iio_buffer *buffer = indio_dev->buffer;
314 int ret, i, attrn, attrcount, attrcount_orig = 0;
317 indio_dev->groups[indio_dev->groupcounter++] = buffer->attrs;
319 if (buffer->scan_el_attrs != NULL) {
320 attr = buffer->scan_el_attrs->attrs;
321 while (*attr++ != NULL)
324 attrcount = attrcount_orig;
325 INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
328 for (i = 0; i < num_channels; i++) {
329 if (channels[i].scan_index < 0)
332 /* Establish necessary mask length */
333 if (channels[i].scan_index >
334 (int)indio_dev->masklength - 1)
335 indio_dev->masklength
336 = channels[i].scan_index + 1;
338 ret = iio_buffer_add_channel_sysfs(indio_dev,
341 goto error_cleanup_dynamic;
343 if (channels[i].type == IIO_TIMESTAMP)
344 indio_dev->scan_index_timestamp =
345 channels[i].scan_index;
347 if (indio_dev->masklength && buffer->scan_mask == NULL) {
348 buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
349 sizeof(*buffer->scan_mask),
351 if (buffer->scan_mask == NULL) {
353 goto error_cleanup_dynamic;
358 buffer->scan_el_group.name = iio_scan_elements_group_name;
360 buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
361 sizeof(buffer->scan_el_group.attrs[0]),
363 if (buffer->scan_el_group.attrs == NULL) {
365 goto error_free_scan_mask;
367 if (buffer->scan_el_attrs)
368 memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
369 sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
370 attrn = attrcount_orig;
372 list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
373 buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
374 indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
378 error_free_scan_mask:
379 kfree(buffer->scan_mask);
380 error_cleanup_dynamic:
381 iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
385 EXPORT_SYMBOL(iio_buffer_register);
387 void iio_buffer_unregister(struct iio_dev *indio_dev)
389 kfree(indio_dev->buffer->scan_mask);
390 kfree(indio_dev->buffer->scan_el_group.attrs);
391 iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
393 EXPORT_SYMBOL(iio_buffer_unregister);
395 ssize_t iio_buffer_read_length(struct device *dev,
396 struct device_attribute *attr,
399 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
400 struct iio_buffer *buffer = indio_dev->buffer;
402 if (buffer->access->get_length)
403 return sprintf(buf, "%d\n",
404 buffer->access->get_length(buffer));
408 EXPORT_SYMBOL(iio_buffer_read_length);
410 ssize_t iio_buffer_write_length(struct device *dev,
411 struct device_attribute *attr,
415 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
416 struct iio_buffer *buffer = indio_dev->buffer;
420 ret = kstrtouint(buf, 10, &val);
424 if (buffer->access->get_length)
425 if (val == buffer->access->get_length(buffer))
428 mutex_lock(&indio_dev->mlock);
429 if (iio_buffer_is_active(indio_dev->buffer)) {
432 if (buffer->access->set_length)
433 buffer->access->set_length(buffer, val);
436 mutex_unlock(&indio_dev->mlock);
438 return ret ? ret : len;
440 EXPORT_SYMBOL(iio_buffer_write_length);
442 ssize_t iio_buffer_show_enable(struct device *dev,
443 struct device_attribute *attr,
446 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
447 return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
449 EXPORT_SYMBOL(iio_buffer_show_enable);
451 /* Note NULL used as error indicator as it doesn't make sense. */
452 static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
453 unsigned int masklength,
454 const unsigned long *mask)
456 if (bitmap_empty(mask, masklength))
459 if (bitmap_subset(mask, av_masks, masklength))
461 av_masks += BITS_TO_LONGS(masklength);
466 static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
467 const unsigned long *mask, bool timestamp)
469 const struct iio_chan_spec *ch;
473 /* How much space will the demuxed element take? */
474 for_each_set_bit(i, mask,
475 indio_dev->masklength) {
476 ch = iio_find_channel_from_si(indio_dev, i);
477 length = ch->scan_type.storagebits / 8;
478 bytes = ALIGN(bytes, length);
482 ch = iio_find_channel_from_si(indio_dev,
483 indio_dev->scan_index_timestamp);
484 length = ch->scan_type.storagebits / 8;
485 bytes = ALIGN(bytes, length);
491 static void iio_buffer_activate(struct iio_dev *indio_dev,
492 struct iio_buffer *buffer)
494 iio_buffer_get(buffer);
495 list_add(&buffer->buffer_list, &indio_dev->buffer_list);
498 static void iio_buffer_deactivate(struct iio_buffer *buffer)
500 list_del_init(&buffer->buffer_list);
501 iio_buffer_put(buffer);
504 void iio_disable_all_buffers(struct iio_dev *indio_dev)
506 struct iio_buffer *buffer, *_buffer;
508 if (list_empty(&indio_dev->buffer_list))
511 if (indio_dev->setup_ops->predisable)
512 indio_dev->setup_ops->predisable(indio_dev);
514 list_for_each_entry_safe(buffer, _buffer,
515 &indio_dev->buffer_list, buffer_list)
516 iio_buffer_deactivate(buffer);
518 indio_dev->currentmode = INDIO_DIRECT_MODE;
519 if (indio_dev->setup_ops->postdisable)
520 indio_dev->setup_ops->postdisable(indio_dev);
522 if (indio_dev->available_scan_masks == NULL)
523 kfree(indio_dev->active_scan_mask);
526 static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
527 struct iio_buffer *buffer)
531 if (!buffer->access->set_bytes_per_datum)
534 bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
535 buffer->scan_timestamp);
537 buffer->access->set_bytes_per_datum(buffer, bytes);
540 static int __iio_update_buffers(struct iio_dev *indio_dev,
541 struct iio_buffer *insert_buffer,
542 struct iio_buffer *remove_buffer)
546 struct iio_buffer *buffer;
547 unsigned long *compound_mask;
548 const unsigned long *old_mask;
550 /* Wind down existing buffers - iff there are any */
551 if (!list_empty(&indio_dev->buffer_list)) {
552 if (indio_dev->setup_ops->predisable) {
553 ret = indio_dev->setup_ops->predisable(indio_dev);
557 indio_dev->currentmode = INDIO_DIRECT_MODE;
558 if (indio_dev->setup_ops->postdisable) {
559 ret = indio_dev->setup_ops->postdisable(indio_dev);
564 /* Keep a copy of current setup to allow roll back */
565 old_mask = indio_dev->active_scan_mask;
566 if (!indio_dev->available_scan_masks)
567 indio_dev->active_scan_mask = NULL;
570 iio_buffer_deactivate(remove_buffer);
572 iio_buffer_activate(indio_dev, insert_buffer);
574 /* If no buffers in list, we are done */
575 if (list_empty(&indio_dev->buffer_list)) {
576 indio_dev->currentmode = INDIO_DIRECT_MODE;
577 if (indio_dev->available_scan_masks == NULL)
582 /* What scan mask do we actually have? */
583 compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
584 sizeof(long), GFP_KERNEL);
585 if (compound_mask == NULL) {
586 if (indio_dev->available_scan_masks == NULL)
590 indio_dev->scan_timestamp = 0;
592 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
593 bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
594 indio_dev->masklength);
595 indio_dev->scan_timestamp |= buffer->scan_timestamp;
597 if (indio_dev->available_scan_masks) {
598 indio_dev->active_scan_mask =
599 iio_scan_mask_match(indio_dev->available_scan_masks,
600 indio_dev->masklength,
602 if (indio_dev->active_scan_mask == NULL) {
605 * Note can only occur when adding a buffer.
607 iio_buffer_deactivate(insert_buffer);
609 indio_dev->active_scan_mask = old_mask;
613 kfree(compound_mask);
619 indio_dev->active_scan_mask = compound_mask;
622 iio_update_demux(indio_dev);
625 if (indio_dev->setup_ops->preenable) {
626 ret = indio_dev->setup_ops->preenable(indio_dev);
629 "Buffer not started: buffer preenable failed (%d)\n", ret);
630 goto error_remove_inserted;
633 indio_dev->scan_bytes =
634 iio_compute_scan_bytes(indio_dev,
635 indio_dev->active_scan_mask,
636 indio_dev->scan_timestamp);
637 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
638 iio_buffer_update_bytes_per_datum(indio_dev, buffer);
639 if (buffer->access->request_update) {
640 ret = buffer->access->request_update(buffer);
643 "Buffer not started: buffer parameter update failed (%d)\n", ret);
644 goto error_run_postdisable;
648 if (indio_dev->info->update_scan_mode) {
649 ret = indio_dev->info
650 ->update_scan_mode(indio_dev,
651 indio_dev->active_scan_mask);
653 printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret);
654 goto error_run_postdisable;
657 /* Definitely possible for devices to support both of these. */
658 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED) {
659 if (!indio_dev->trig) {
660 printk(KERN_INFO "Buffer not started: no trigger\n");
662 /* Can only occur on first buffer */
663 goto error_run_postdisable;
665 indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
666 } else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) {
667 indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
668 } else { /* Should never be reached */
670 goto error_run_postdisable;
673 if (indio_dev->setup_ops->postenable) {
674 ret = indio_dev->setup_ops->postenable(indio_dev);
677 "Buffer not started: postenable failed (%d)\n", ret);
678 indio_dev->currentmode = INDIO_DIRECT_MODE;
679 if (indio_dev->setup_ops->postdisable)
680 indio_dev->setup_ops->postdisable(indio_dev);
681 goto error_disable_all_buffers;
685 if (indio_dev->available_scan_masks)
686 kfree(compound_mask);
692 error_disable_all_buffers:
693 indio_dev->currentmode = INDIO_DIRECT_MODE;
694 error_run_postdisable:
695 if (indio_dev->setup_ops->postdisable)
696 indio_dev->setup_ops->postdisable(indio_dev);
697 error_remove_inserted:
699 iio_buffer_deactivate(insert_buffer);
700 indio_dev->active_scan_mask = old_mask;
701 kfree(compound_mask);
705 int iio_update_buffers(struct iio_dev *indio_dev,
706 struct iio_buffer *insert_buffer,
707 struct iio_buffer *remove_buffer)
711 if (insert_buffer == remove_buffer)
714 mutex_lock(&indio_dev->info_exist_lock);
715 mutex_lock(&indio_dev->mlock);
717 if (insert_buffer && iio_buffer_is_active(insert_buffer))
718 insert_buffer = NULL;
720 if (remove_buffer && !iio_buffer_is_active(remove_buffer))
721 remove_buffer = NULL;
723 if (!insert_buffer && !remove_buffer) {
728 if (indio_dev->info == NULL) {
733 ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
736 mutex_unlock(&indio_dev->mlock);
737 mutex_unlock(&indio_dev->info_exist_lock);
741 EXPORT_SYMBOL_GPL(iio_update_buffers);
743 ssize_t iio_buffer_store_enable(struct device *dev,
744 struct device_attribute *attr,
749 bool requested_state;
750 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
753 ret = strtobool(buf, &requested_state);
757 mutex_lock(&indio_dev->mlock);
759 /* Find out if it is in the list */
760 inlist = iio_buffer_is_active(indio_dev->buffer);
761 /* Already in desired state */
762 if (inlist == requested_state)
766 ret = __iio_update_buffers(indio_dev,
767 indio_dev->buffer, NULL);
769 ret = __iio_update_buffers(indio_dev,
770 NULL, indio_dev->buffer);
775 mutex_unlock(&indio_dev->mlock);
776 return (ret < 0) ? ret : len;
778 EXPORT_SYMBOL(iio_buffer_store_enable);
781 * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
782 * @indio_dev: the iio device
783 * @mask: scan mask to be checked
785 * Return true if exactly one bit is set in the scan mask, false otherwise. It
786 * can be used for devices where only one channel can be active for sampling at
789 bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
790 const unsigned long *mask)
792 return bitmap_weight(mask, indio_dev->masklength) == 1;
794 EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
796 static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
797 const unsigned long *mask)
799 if (!indio_dev->setup_ops->validate_scan_mask)
802 return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
806 * iio_scan_mask_set() - set particular bit in the scan mask
807 * @indio_dev: the iio device
808 * @buffer: the buffer whose scan mask we are interested in
809 * @bit: the bit to be set.
811 * Note that at this point we have no way of knowing what other
812 * buffers might request, hence this code only verifies that the
813 * individual buffers request is plausible.
815 int iio_scan_mask_set(struct iio_dev *indio_dev,
816 struct iio_buffer *buffer, int bit)
818 const unsigned long *mask;
819 unsigned long *trialmask;
821 trialmask = kmalloc(sizeof(*trialmask)*
822 BITS_TO_LONGS(indio_dev->masklength),
825 if (trialmask == NULL)
827 if (!indio_dev->masklength) {
828 WARN_ON("Trying to set scanmask prior to registering buffer\n");
829 goto err_invalid_mask;
831 bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
832 set_bit(bit, trialmask);
834 if (!iio_validate_scan_mask(indio_dev, trialmask))
835 goto err_invalid_mask;
837 if (indio_dev->available_scan_masks) {
838 mask = iio_scan_mask_match(indio_dev->available_scan_masks,
839 indio_dev->masklength,
842 goto err_invalid_mask;
844 bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
854 EXPORT_SYMBOL_GPL(iio_scan_mask_set);
856 int iio_scan_mask_query(struct iio_dev *indio_dev,
857 struct iio_buffer *buffer, int bit)
859 if (bit > indio_dev->masklength)
862 if (!buffer->scan_mask)
865 return test_bit(bit, buffer->scan_mask);
867 EXPORT_SYMBOL_GPL(iio_scan_mask_query);
870 * struct iio_demux_table() - table describing demux memcpy ops
871 * @from: index to copy from
872 * @to: index to copy to
873 * @length: how many bytes to copy
874 * @l: list head used for management
876 struct iio_demux_table {
883 static const void *iio_demux(struct iio_buffer *buffer,
886 struct iio_demux_table *t;
888 if (list_empty(&buffer->demux_list))
890 list_for_each_entry(t, &buffer->demux_list, l)
891 memcpy(buffer->demux_bounce + t->to,
892 datain + t->from, t->length);
894 return buffer->demux_bounce;
897 static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
899 const void *dataout = iio_demux(buffer, data);
901 return buffer->access->store_to(buffer, dataout);
904 static void iio_buffer_demux_free(struct iio_buffer *buffer)
906 struct iio_demux_table *p, *q;
907 list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
914 int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
917 struct iio_buffer *buf;
919 list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) {
920 ret = iio_push_to_buffer(buf, data);
927 EXPORT_SYMBOL_GPL(iio_push_to_buffers);
929 static int iio_buffer_update_demux(struct iio_dev *indio_dev,
930 struct iio_buffer *buffer)
932 const struct iio_chan_spec *ch;
933 int ret, in_ind = -1, out_ind, length;
934 unsigned in_loc = 0, out_loc = 0;
935 struct iio_demux_table *p;
937 /* Clear out any old demux */
938 iio_buffer_demux_free(buffer);
939 kfree(buffer->demux_bounce);
940 buffer->demux_bounce = NULL;
942 /* First work out which scan mode we will actually have */
943 if (bitmap_equal(indio_dev->active_scan_mask,
945 indio_dev->masklength))
948 /* Now we have the two masks, work from least sig and build up sizes */
949 for_each_set_bit(out_ind,
950 indio_dev->active_scan_mask,
951 indio_dev->masklength) {
952 in_ind = find_next_bit(indio_dev->active_scan_mask,
953 indio_dev->masklength,
955 while (in_ind != out_ind) {
956 in_ind = find_next_bit(indio_dev->active_scan_mask,
957 indio_dev->masklength,
959 ch = iio_find_channel_from_si(indio_dev, in_ind);
960 length = ch->scan_type.storagebits/8;
961 /* Make sure we are aligned */
964 in_loc += length - in_loc % length;
966 p = kmalloc(sizeof(*p), GFP_KERNEL);
969 goto error_clear_mux_table;
971 ch = iio_find_channel_from_si(indio_dev, in_ind);
972 length = ch->scan_type.storagebits/8;
973 if (out_loc % length)
974 out_loc += length - out_loc % length;
976 in_loc += length - in_loc % length;
980 list_add_tail(&p->l, &buffer->demux_list);
984 /* Relies on scan_timestamp being last */
985 if (buffer->scan_timestamp) {
986 p = kmalloc(sizeof(*p), GFP_KERNEL);
989 goto error_clear_mux_table;
991 ch = iio_find_channel_from_si(indio_dev,
992 indio_dev->scan_index_timestamp);
993 length = ch->scan_type.storagebits/8;
994 if (out_loc % length)
995 out_loc += length - out_loc % length;
997 in_loc += length - in_loc % length;
1001 list_add_tail(&p->l, &buffer->demux_list);
1005 buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
1006 if (buffer->demux_bounce == NULL) {
1008 goto error_clear_mux_table;
1012 error_clear_mux_table:
1013 iio_buffer_demux_free(buffer);
1018 int iio_update_demux(struct iio_dev *indio_dev)
1020 struct iio_buffer *buffer;
1023 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
1024 ret = iio_buffer_update_demux(indio_dev, buffer);
1026 goto error_clear_mux_table;
1030 error_clear_mux_table:
1031 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
1032 iio_buffer_demux_free(buffer);
1036 EXPORT_SYMBOL_GPL(iio_update_demux);
1039 * iio_buffer_release() - Free a buffer's resources
1040 * @ref: Pointer to the kref embedded in the iio_buffer struct
1042 * This function is called when the last reference to the buffer has been
1043 * dropped. It will typically free all resources allocated by the buffer. Do not
1044 * call this function manually, always use iio_buffer_put() when done using a
1047 static void iio_buffer_release(struct kref *ref)
1049 struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
1051 buffer->access->release(buffer);
1055 * iio_buffer_get() - Grab a reference to the buffer
1056 * @buffer: The buffer to grab a reference for, may be NULL
1058 * Returns the pointer to the buffer that was passed into the function.
1060 struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
1063 kref_get(&buffer->ref);
1067 EXPORT_SYMBOL_GPL(iio_buffer_get);
1070 * iio_buffer_put() - Release the reference to the buffer
1071 * @buffer: The buffer to release the reference for, may be NULL
1073 void iio_buffer_put(struct iio_buffer *buffer)
1076 kref_put(&buffer->ref, iio_buffer_release);
1078 EXPORT_SYMBOL_GPL(iio_buffer_put);