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 /* Ensure ret is 0 or 1. */
169 ret
= !!test_bit(to_iio_dev_attr(attr
)->address
,
170 indio_dev
->buffer
->scan_mask
);
172 return sprintf(buf
, "%d\n", ret
);
175 static int iio_scan_mask_clear(struct iio_buffer
*buffer
, int bit
)
177 clear_bit(bit
, buffer
->scan_mask
);
181 static ssize_t
iio_scan_el_store(struct device
*dev
,
182 struct device_attribute
*attr
,
188 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
189 struct iio_buffer
*buffer
= indio_dev
->buffer
;
190 struct iio_dev_attr
*this_attr
= to_iio_dev_attr(attr
);
192 ret
= strtobool(buf
, &state
);
195 mutex_lock(&indio_dev
->mlock
);
196 if (iio_buffer_is_active(indio_dev
->buffer
)) {
200 ret
= iio_scan_mask_query(indio_dev
, buffer
, this_attr
->address
);
204 ret
= iio_scan_mask_clear(buffer
, this_attr
->address
);
207 } else if (state
&& !ret
) {
208 ret
= iio_scan_mask_set(indio_dev
, buffer
, this_attr
->address
);
214 mutex_unlock(&indio_dev
->mlock
);
216 return ret
< 0 ? ret
: len
;
220 static ssize_t
iio_scan_el_ts_show(struct device
*dev
,
221 struct device_attribute
*attr
,
224 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
225 return sprintf(buf
, "%d\n", indio_dev
->buffer
->scan_timestamp
);
228 static ssize_t
iio_scan_el_ts_store(struct device
*dev
,
229 struct device_attribute
*attr
,
234 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
237 ret
= strtobool(buf
, &state
);
241 mutex_lock(&indio_dev
->mlock
);
242 if (iio_buffer_is_active(indio_dev
->buffer
)) {
246 indio_dev
->buffer
->scan_timestamp
= state
;
248 mutex_unlock(&indio_dev
->mlock
);
250 return ret
? ret
: len
;
253 static int iio_buffer_add_channel_sysfs(struct iio_dev
*indio_dev
,
254 const struct iio_chan_spec
*chan
)
256 int ret
, attrcount
= 0;
257 struct iio_buffer
*buffer
= indio_dev
->buffer
;
259 ret
= __iio_add_chan_devattr("index",
261 &iio_show_scan_index
,
266 &buffer
->scan_el_dev_attr_list
);
270 ret
= __iio_add_chan_devattr("type",
272 &iio_show_fixed_type
,
277 &buffer
->scan_el_dev_attr_list
);
281 if (chan
->type
!= IIO_TIMESTAMP
)
282 ret
= __iio_add_chan_devattr("en",
289 &buffer
->scan_el_dev_attr_list
);
291 ret
= __iio_add_chan_devattr("en",
293 &iio_scan_el_ts_show
,
294 &iio_scan_el_ts_store
,
298 &buffer
->scan_el_dev_attr_list
);
306 static const char * const iio_scan_elements_group_name
= "scan_elements";
308 int iio_buffer_register(struct iio_dev
*indio_dev
,
309 const struct iio_chan_spec
*channels
,
312 struct iio_dev_attr
*p
;
313 struct attribute
**attr
;
314 struct iio_buffer
*buffer
= indio_dev
->buffer
;
315 int ret
, i
, attrn
, attrcount
, attrcount_orig
= 0;
318 indio_dev
->groups
[indio_dev
->groupcounter
++] = buffer
->attrs
;
320 if (buffer
->scan_el_attrs
!= NULL
) {
321 attr
= buffer
->scan_el_attrs
->attrs
;
322 while (*attr
++ != NULL
)
325 attrcount
= attrcount_orig
;
326 INIT_LIST_HEAD(&buffer
->scan_el_dev_attr_list
);
329 for (i
= 0; i
< num_channels
; i
++) {
330 if (channels
[i
].scan_index
< 0)
333 /* Establish necessary mask length */
334 if (channels
[i
].scan_index
>
335 (int)indio_dev
->masklength
- 1)
336 indio_dev
->masklength
337 = channels
[i
].scan_index
+ 1;
339 ret
= iio_buffer_add_channel_sysfs(indio_dev
,
342 goto error_cleanup_dynamic
;
344 if (channels
[i
].type
== IIO_TIMESTAMP
)
345 indio_dev
->scan_index_timestamp
=
346 channels
[i
].scan_index
;
348 if (indio_dev
->masklength
&& buffer
->scan_mask
== NULL
) {
349 buffer
->scan_mask
= kcalloc(BITS_TO_LONGS(indio_dev
->masklength
),
350 sizeof(*buffer
->scan_mask
),
352 if (buffer
->scan_mask
== NULL
) {
354 goto error_cleanup_dynamic
;
359 buffer
->scan_el_group
.name
= iio_scan_elements_group_name
;
361 buffer
->scan_el_group
.attrs
= kcalloc(attrcount
+ 1,
362 sizeof(buffer
->scan_el_group
.attrs
[0]),
364 if (buffer
->scan_el_group
.attrs
== NULL
) {
366 goto error_free_scan_mask
;
368 if (buffer
->scan_el_attrs
)
369 memcpy(buffer
->scan_el_group
.attrs
, buffer
->scan_el_attrs
,
370 sizeof(buffer
->scan_el_group
.attrs
[0])*attrcount_orig
);
371 attrn
= attrcount_orig
;
373 list_for_each_entry(p
, &buffer
->scan_el_dev_attr_list
, l
)
374 buffer
->scan_el_group
.attrs
[attrn
++] = &p
->dev_attr
.attr
;
375 indio_dev
->groups
[indio_dev
->groupcounter
++] = &buffer
->scan_el_group
;
379 error_free_scan_mask
:
380 kfree(buffer
->scan_mask
);
381 error_cleanup_dynamic
:
382 iio_free_chan_devattr_list(&buffer
->scan_el_dev_attr_list
);
386 EXPORT_SYMBOL(iio_buffer_register
);
388 void iio_buffer_unregister(struct iio_dev
*indio_dev
)
390 kfree(indio_dev
->buffer
->scan_mask
);
391 kfree(indio_dev
->buffer
->scan_el_group
.attrs
);
392 iio_free_chan_devattr_list(&indio_dev
->buffer
->scan_el_dev_attr_list
);
394 EXPORT_SYMBOL(iio_buffer_unregister
);
396 ssize_t
iio_buffer_read_length(struct device
*dev
,
397 struct device_attribute
*attr
,
400 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
401 struct iio_buffer
*buffer
= indio_dev
->buffer
;
403 if (buffer
->access
->get_length
)
404 return sprintf(buf
, "%d\n",
405 buffer
->access
->get_length(buffer
));
409 EXPORT_SYMBOL(iio_buffer_read_length
);
411 ssize_t
iio_buffer_write_length(struct device
*dev
,
412 struct device_attribute
*attr
,
416 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
417 struct iio_buffer
*buffer
= indio_dev
->buffer
;
421 ret
= kstrtouint(buf
, 10, &val
);
425 if (buffer
->access
->get_length
)
426 if (val
== buffer
->access
->get_length(buffer
))
429 mutex_lock(&indio_dev
->mlock
);
430 if (iio_buffer_is_active(indio_dev
->buffer
)) {
433 if (buffer
->access
->set_length
)
434 buffer
->access
->set_length(buffer
, val
);
437 mutex_unlock(&indio_dev
->mlock
);
439 return ret
? ret
: len
;
441 EXPORT_SYMBOL(iio_buffer_write_length
);
443 ssize_t
iio_buffer_show_enable(struct device
*dev
,
444 struct device_attribute
*attr
,
447 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
448 return sprintf(buf
, "%d\n", iio_buffer_is_active(indio_dev
->buffer
));
450 EXPORT_SYMBOL(iio_buffer_show_enable
);
452 /* Note NULL used as error indicator as it doesn't make sense. */
453 static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks
,
454 unsigned int masklength
,
455 const unsigned long *mask
)
457 if (bitmap_empty(mask
, masklength
))
460 if (bitmap_subset(mask
, av_masks
, masklength
))
462 av_masks
+= BITS_TO_LONGS(masklength
);
467 static int iio_compute_scan_bytes(struct iio_dev
*indio_dev
,
468 const unsigned long *mask
, bool timestamp
)
470 const struct iio_chan_spec
*ch
;
474 /* How much space will the demuxed element take? */
475 for_each_set_bit(i
, mask
,
476 indio_dev
->masklength
) {
477 ch
= iio_find_channel_from_si(indio_dev
, i
);
478 length
= ch
->scan_type
.storagebits
/ 8;
479 bytes
= ALIGN(bytes
, length
);
483 ch
= iio_find_channel_from_si(indio_dev
,
484 indio_dev
->scan_index_timestamp
);
485 length
= ch
->scan_type
.storagebits
/ 8;
486 bytes
= ALIGN(bytes
, length
);
492 static void iio_buffer_activate(struct iio_dev
*indio_dev
,
493 struct iio_buffer
*buffer
)
495 iio_buffer_get(buffer
);
496 list_add(&buffer
->buffer_list
, &indio_dev
->buffer_list
);
499 static void iio_buffer_deactivate(struct iio_buffer
*buffer
)
501 list_del_init(&buffer
->buffer_list
);
502 iio_buffer_put(buffer
);
505 void iio_disable_all_buffers(struct iio_dev
*indio_dev
)
507 struct iio_buffer
*buffer
, *_buffer
;
509 if (list_empty(&indio_dev
->buffer_list
))
512 if (indio_dev
->setup_ops
->predisable
)
513 indio_dev
->setup_ops
->predisable(indio_dev
);
515 list_for_each_entry_safe(buffer
, _buffer
,
516 &indio_dev
->buffer_list
, buffer_list
)
517 iio_buffer_deactivate(buffer
);
519 indio_dev
->currentmode
= INDIO_DIRECT_MODE
;
520 if (indio_dev
->setup_ops
->postdisable
)
521 indio_dev
->setup_ops
->postdisable(indio_dev
);
523 if (indio_dev
->available_scan_masks
== NULL
)
524 kfree(indio_dev
->active_scan_mask
);
527 static void iio_buffer_update_bytes_per_datum(struct iio_dev
*indio_dev
,
528 struct iio_buffer
*buffer
)
532 if (!buffer
->access
->set_bytes_per_datum
)
535 bytes
= iio_compute_scan_bytes(indio_dev
, buffer
->scan_mask
,
536 buffer
->scan_timestamp
);
538 buffer
->access
->set_bytes_per_datum(buffer
, bytes
);
541 static int __iio_update_buffers(struct iio_dev
*indio_dev
,
542 struct iio_buffer
*insert_buffer
,
543 struct iio_buffer
*remove_buffer
)
547 struct iio_buffer
*buffer
;
548 unsigned long *compound_mask
;
549 const unsigned long *old_mask
;
551 /* Wind down existing buffers - iff there are any */
552 if (!list_empty(&indio_dev
->buffer_list
)) {
553 if (indio_dev
->setup_ops
->predisable
) {
554 ret
= indio_dev
->setup_ops
->predisable(indio_dev
);
558 indio_dev
->currentmode
= INDIO_DIRECT_MODE
;
559 if (indio_dev
->setup_ops
->postdisable
) {
560 ret
= indio_dev
->setup_ops
->postdisable(indio_dev
);
565 /* Keep a copy of current setup to allow roll back */
566 old_mask
= indio_dev
->active_scan_mask
;
567 if (!indio_dev
->available_scan_masks
)
568 indio_dev
->active_scan_mask
= NULL
;
571 iio_buffer_deactivate(remove_buffer
);
573 iio_buffer_activate(indio_dev
, insert_buffer
);
575 /* If no buffers in list, we are done */
576 if (list_empty(&indio_dev
->buffer_list
)) {
577 indio_dev
->currentmode
= INDIO_DIRECT_MODE
;
578 if (indio_dev
->available_scan_masks
== NULL
)
583 /* What scan mask do we actually have? */
584 compound_mask
= kcalloc(BITS_TO_LONGS(indio_dev
->masklength
),
585 sizeof(long), GFP_KERNEL
);
586 if (compound_mask
== NULL
) {
587 if (indio_dev
->available_scan_masks
== NULL
)
591 indio_dev
->scan_timestamp
= 0;
593 list_for_each_entry(buffer
, &indio_dev
->buffer_list
, buffer_list
) {
594 bitmap_or(compound_mask
, compound_mask
, buffer
->scan_mask
,
595 indio_dev
->masklength
);
596 indio_dev
->scan_timestamp
|= buffer
->scan_timestamp
;
598 if (indio_dev
->available_scan_masks
) {
599 indio_dev
->active_scan_mask
=
600 iio_scan_mask_match(indio_dev
->available_scan_masks
,
601 indio_dev
->masklength
,
603 if (indio_dev
->active_scan_mask
== NULL
) {
606 * Note can only occur when adding a buffer.
608 iio_buffer_deactivate(insert_buffer
);
610 indio_dev
->active_scan_mask
= old_mask
;
614 kfree(compound_mask
);
620 indio_dev
->active_scan_mask
= compound_mask
;
623 iio_update_demux(indio_dev
);
626 if (indio_dev
->setup_ops
->preenable
) {
627 ret
= indio_dev
->setup_ops
->preenable(indio_dev
);
630 "Buffer not started: buffer preenable failed (%d)\n", ret
);
631 goto error_remove_inserted
;
634 indio_dev
->scan_bytes
=
635 iio_compute_scan_bytes(indio_dev
,
636 indio_dev
->active_scan_mask
,
637 indio_dev
->scan_timestamp
);
638 list_for_each_entry(buffer
, &indio_dev
->buffer_list
, buffer_list
) {
639 iio_buffer_update_bytes_per_datum(indio_dev
, buffer
);
640 if (buffer
->access
->request_update
) {
641 ret
= buffer
->access
->request_update(buffer
);
644 "Buffer not started: buffer parameter update failed (%d)\n", ret
);
645 goto error_run_postdisable
;
649 if (indio_dev
->info
->update_scan_mode
) {
650 ret
= indio_dev
->info
651 ->update_scan_mode(indio_dev
,
652 indio_dev
->active_scan_mask
);
654 printk(KERN_INFO
"Buffer not started: update scan mode failed (%d)\n", ret
);
655 goto error_run_postdisable
;
658 /* Definitely possible for devices to support both of these. */
659 if (indio_dev
->modes
& INDIO_BUFFER_TRIGGERED
) {
660 if (!indio_dev
->trig
) {
661 printk(KERN_INFO
"Buffer not started: no trigger\n");
663 /* Can only occur on first buffer */
664 goto error_run_postdisable
;
666 indio_dev
->currentmode
= INDIO_BUFFER_TRIGGERED
;
667 } else if (indio_dev
->modes
& INDIO_BUFFER_HARDWARE
) {
668 indio_dev
->currentmode
= INDIO_BUFFER_HARDWARE
;
669 } else { /* Should never be reached */
671 goto error_run_postdisable
;
674 if (indio_dev
->setup_ops
->postenable
) {
675 ret
= indio_dev
->setup_ops
->postenable(indio_dev
);
678 "Buffer not started: postenable failed (%d)\n", ret
);
679 indio_dev
->currentmode
= INDIO_DIRECT_MODE
;
680 if (indio_dev
->setup_ops
->postdisable
)
681 indio_dev
->setup_ops
->postdisable(indio_dev
);
682 goto error_disable_all_buffers
;
686 if (indio_dev
->available_scan_masks
)
687 kfree(compound_mask
);
693 error_disable_all_buffers
:
694 indio_dev
->currentmode
= INDIO_DIRECT_MODE
;
695 error_run_postdisable
:
696 if (indio_dev
->setup_ops
->postdisable
)
697 indio_dev
->setup_ops
->postdisable(indio_dev
);
698 error_remove_inserted
:
700 iio_buffer_deactivate(insert_buffer
);
701 indio_dev
->active_scan_mask
= old_mask
;
702 kfree(compound_mask
);
706 int iio_update_buffers(struct iio_dev
*indio_dev
,
707 struct iio_buffer
*insert_buffer
,
708 struct iio_buffer
*remove_buffer
)
712 if (insert_buffer
== remove_buffer
)
715 mutex_lock(&indio_dev
->info_exist_lock
);
716 mutex_lock(&indio_dev
->mlock
);
718 if (insert_buffer
&& iio_buffer_is_active(insert_buffer
))
719 insert_buffer
= NULL
;
721 if (remove_buffer
&& !iio_buffer_is_active(remove_buffer
))
722 remove_buffer
= NULL
;
724 if (!insert_buffer
&& !remove_buffer
) {
729 if (indio_dev
->info
== NULL
) {
734 ret
= __iio_update_buffers(indio_dev
, insert_buffer
, remove_buffer
);
737 mutex_unlock(&indio_dev
->mlock
);
738 mutex_unlock(&indio_dev
->info_exist_lock
);
742 EXPORT_SYMBOL_GPL(iio_update_buffers
);
744 ssize_t
iio_buffer_store_enable(struct device
*dev
,
745 struct device_attribute
*attr
,
750 bool requested_state
;
751 struct iio_dev
*indio_dev
= dev_to_iio_dev(dev
);
754 ret
= strtobool(buf
, &requested_state
);
758 mutex_lock(&indio_dev
->mlock
);
760 /* Find out if it is in the list */
761 inlist
= iio_buffer_is_active(indio_dev
->buffer
);
762 /* Already in desired state */
763 if (inlist
== requested_state
)
767 ret
= __iio_update_buffers(indio_dev
,
768 indio_dev
->buffer
, NULL
);
770 ret
= __iio_update_buffers(indio_dev
,
771 NULL
, indio_dev
->buffer
);
776 mutex_unlock(&indio_dev
->mlock
);
777 return (ret
< 0) ? ret
: len
;
779 EXPORT_SYMBOL(iio_buffer_store_enable
);
782 * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
783 * @indio_dev: the iio device
784 * @mask: scan mask to be checked
786 * Return true if exactly one bit is set in the scan mask, false otherwise. It
787 * can be used for devices where only one channel can be active for sampling at
790 bool iio_validate_scan_mask_onehot(struct iio_dev
*indio_dev
,
791 const unsigned long *mask
)
793 return bitmap_weight(mask
, indio_dev
->masklength
) == 1;
795 EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot
);
797 static bool iio_validate_scan_mask(struct iio_dev
*indio_dev
,
798 const unsigned long *mask
)
800 if (!indio_dev
->setup_ops
->validate_scan_mask
)
803 return indio_dev
->setup_ops
->validate_scan_mask(indio_dev
, mask
);
807 * iio_scan_mask_set() - set particular bit in the scan mask
808 * @indio_dev: the iio device
809 * @buffer: the buffer whose scan mask we are interested in
810 * @bit: the bit to be set.
812 * Note that at this point we have no way of knowing what other
813 * buffers might request, hence this code only verifies that the
814 * individual buffers request is plausible.
816 int iio_scan_mask_set(struct iio_dev
*indio_dev
,
817 struct iio_buffer
*buffer
, int bit
)
819 const unsigned long *mask
;
820 unsigned long *trialmask
;
822 trialmask
= kmalloc(sizeof(*trialmask
)*
823 BITS_TO_LONGS(indio_dev
->masklength
),
826 if (trialmask
== NULL
)
828 if (!indio_dev
->masklength
) {
829 WARN_ON("Trying to set scanmask prior to registering buffer\n");
830 goto err_invalid_mask
;
832 bitmap_copy(trialmask
, buffer
->scan_mask
, indio_dev
->masklength
);
833 set_bit(bit
, trialmask
);
835 if (!iio_validate_scan_mask(indio_dev
, trialmask
))
836 goto err_invalid_mask
;
838 if (indio_dev
->available_scan_masks
) {
839 mask
= iio_scan_mask_match(indio_dev
->available_scan_masks
,
840 indio_dev
->masklength
,
843 goto err_invalid_mask
;
845 bitmap_copy(buffer
->scan_mask
, trialmask
, indio_dev
->masklength
);
855 EXPORT_SYMBOL_GPL(iio_scan_mask_set
);
857 int iio_scan_mask_query(struct iio_dev
*indio_dev
,
858 struct iio_buffer
*buffer
, int bit
)
860 if (bit
> indio_dev
->masklength
)
863 if (!buffer
->scan_mask
)
866 /* Ensure return value is 0 or 1. */
867 return !!test_bit(bit
, buffer
->scan_mask
);
869 EXPORT_SYMBOL_GPL(iio_scan_mask_query
);
872 * struct iio_demux_table() - table describing demux memcpy ops
873 * @from: index to copy from
874 * @to: index to copy to
875 * @length: how many bytes to copy
876 * @l: list head used for management
878 struct iio_demux_table
{
885 static const void *iio_demux(struct iio_buffer
*buffer
,
888 struct iio_demux_table
*t
;
890 if (list_empty(&buffer
->demux_list
))
892 list_for_each_entry(t
, &buffer
->demux_list
, l
)
893 memcpy(buffer
->demux_bounce
+ t
->to
,
894 datain
+ t
->from
, t
->length
);
896 return buffer
->demux_bounce
;
899 static int iio_push_to_buffer(struct iio_buffer
*buffer
, const void *data
)
901 const void *dataout
= iio_demux(buffer
, data
);
903 return buffer
->access
->store_to(buffer
, dataout
);
906 static void iio_buffer_demux_free(struct iio_buffer
*buffer
)
908 struct iio_demux_table
*p
, *q
;
909 list_for_each_entry_safe(p
, q
, &buffer
->demux_list
, l
) {
916 int iio_push_to_buffers(struct iio_dev
*indio_dev
, const void *data
)
919 struct iio_buffer
*buf
;
921 list_for_each_entry(buf
, &indio_dev
->buffer_list
, buffer_list
) {
922 ret
= iio_push_to_buffer(buf
, data
);
929 EXPORT_SYMBOL_GPL(iio_push_to_buffers
);
931 static int iio_buffer_update_demux(struct iio_dev
*indio_dev
,
932 struct iio_buffer
*buffer
)
934 const struct iio_chan_spec
*ch
;
935 int ret
, in_ind
= -1, out_ind
, length
;
936 unsigned in_loc
= 0, out_loc
= 0;
937 struct iio_demux_table
*p
;
939 /* Clear out any old demux */
940 iio_buffer_demux_free(buffer
);
941 kfree(buffer
->demux_bounce
);
942 buffer
->demux_bounce
= NULL
;
944 /* First work out which scan mode we will actually have */
945 if (bitmap_equal(indio_dev
->active_scan_mask
,
947 indio_dev
->masklength
))
950 /* Now we have the two masks, work from least sig and build up sizes */
951 for_each_set_bit(out_ind
,
952 indio_dev
->active_scan_mask
,
953 indio_dev
->masklength
) {
954 in_ind
= find_next_bit(indio_dev
->active_scan_mask
,
955 indio_dev
->masklength
,
957 while (in_ind
!= out_ind
) {
958 in_ind
= find_next_bit(indio_dev
->active_scan_mask
,
959 indio_dev
->masklength
,
961 ch
= iio_find_channel_from_si(indio_dev
, in_ind
);
962 length
= ch
->scan_type
.storagebits
/8;
963 /* Make sure we are aligned */
966 in_loc
+= length
- in_loc
% length
;
968 p
= kmalloc(sizeof(*p
), GFP_KERNEL
);
971 goto error_clear_mux_table
;
973 ch
= iio_find_channel_from_si(indio_dev
, in_ind
);
974 length
= ch
->scan_type
.storagebits
/8;
975 if (out_loc
% length
)
976 out_loc
+= length
- out_loc
% length
;
978 in_loc
+= length
- in_loc
% length
;
982 list_add_tail(&p
->l
, &buffer
->demux_list
);
986 /* Relies on scan_timestamp being last */
987 if (buffer
->scan_timestamp
) {
988 p
= kmalloc(sizeof(*p
), GFP_KERNEL
);
991 goto error_clear_mux_table
;
993 ch
= iio_find_channel_from_si(indio_dev
,
994 indio_dev
->scan_index_timestamp
);
995 length
= ch
->scan_type
.storagebits
/8;
996 if (out_loc
% length
)
997 out_loc
+= length
- out_loc
% length
;
999 in_loc
+= length
- in_loc
% length
;
1003 list_add_tail(&p
->l
, &buffer
->demux_list
);
1007 buffer
->demux_bounce
= kzalloc(out_loc
, GFP_KERNEL
);
1008 if (buffer
->demux_bounce
== NULL
) {
1010 goto error_clear_mux_table
;
1014 error_clear_mux_table
:
1015 iio_buffer_demux_free(buffer
);
1020 int iio_update_demux(struct iio_dev
*indio_dev
)
1022 struct iio_buffer
*buffer
;
1025 list_for_each_entry(buffer
, &indio_dev
->buffer_list
, buffer_list
) {
1026 ret
= iio_buffer_update_demux(indio_dev
, buffer
);
1028 goto error_clear_mux_table
;
1032 error_clear_mux_table
:
1033 list_for_each_entry(buffer
, &indio_dev
->buffer_list
, buffer_list
)
1034 iio_buffer_demux_free(buffer
);
1038 EXPORT_SYMBOL_GPL(iio_update_demux
);
1041 * iio_buffer_release() - Free a buffer's resources
1042 * @ref: Pointer to the kref embedded in the iio_buffer struct
1044 * This function is called when the last reference to the buffer has been
1045 * dropped. It will typically free all resources allocated by the buffer. Do not
1046 * call this function manually, always use iio_buffer_put() when done using a
1049 static void iio_buffer_release(struct kref
*ref
)
1051 struct iio_buffer
*buffer
= container_of(ref
, struct iio_buffer
, ref
);
1053 buffer
->access
->release(buffer
);
1057 * iio_buffer_get() - Grab a reference to the buffer
1058 * @buffer: The buffer to grab a reference for, may be NULL
1060 * Returns the pointer to the buffer that was passed into the function.
1062 struct iio_buffer
*iio_buffer_get(struct iio_buffer
*buffer
)
1065 kref_get(&buffer
->ref
);
1069 EXPORT_SYMBOL_GPL(iio_buffer_get
);
1072 * iio_buffer_put() - Release the reference to the buffer
1073 * @buffer: The buffer to release the reference for, may be NULL
1075 void iio_buffer_put(struct iio_buffer
*buffer
)
1078 kref_put(&buffer
->ref
, iio_buffer_release
);
1080 EXPORT_SYMBOL_GPL(iio_buffer_put
);