LXR linux/drivers/iio/buffer/industrialio-buffer-cb.c

   1/* The industrial I/O callback buffer
   2 *
   3 * This program is free software; you can redistribute it and/or modify it
   4 * under the terms of the GNU General Public License version 2 as published by
   5 * the Free Software Foundation.
   6 */
   7
   8#include <linux/kernel.h>
   9#include <linux/module.h>
  10#include <linux/slab.h>
  11#include <linux/err.h>
  12#include <linux/export.h>
  13#include <linux/iio/buffer.h>
  14#include <linux/iio/consumer.h>
  15
  16struct iio_cb_buffer {
  17        struct iio_buffer buffer;
  18        int (*cb)(const void *data, void *private);
  19        void *private;
  20        struct iio_channel *channels;
  21};
  22
  23static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
  24{
  25        return container_of(buffer, struct iio_cb_buffer, buffer);
  26}
  27
  28static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
  29{
  30        struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  31        return cb_buff->cb(data, cb_buff->private);
  32}
  33
  34static void iio_buffer_cb_release(struct iio_buffer *buffer)
  35{
  36        struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  37        kfree(cb_buff->buffer.scan_mask);
  38        kfree(cb_buff);
  39}
  40
  41static const struct iio_buffer_access_funcs iio_cb_access = {
  42        .store_to = &iio_buffer_cb_store_to,
  43        .release = &iio_buffer_cb_release,
  44
  45        .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
  46};
  47
  48struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
  49                                             int (*cb)(const void *data,
  50                                                       void *private),
  51                                             void *private)
  52{
  53        int ret;
  54        struct iio_cb_buffer *cb_buff;
  55        struct iio_dev *indio_dev;
  56        struct iio_channel *chan;
  57
  58        cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  59        if (cb_buff == NULL)
  60                return ERR_PTR(-ENOMEM);
  61
  62        iio_buffer_init(&cb_buff->buffer);
  63
  64        cb_buff->private = private;
  65        cb_buff->cb = cb;
  66        cb_buff->buffer.access = &iio_cb_access;
  67        INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  68
  69        cb_buff->channels = iio_channel_get_all(dev);
  70        if (IS_ERR(cb_buff->channels)) {
  71                ret = PTR_ERR(cb_buff->channels);
  72                goto error_free_cb_buff;
  73        }
  74
  75        indio_dev = cb_buff->channels[0].indio_dev;
  76        cb_buff->buffer.scan_mask
  77                = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
  78                          GFP_KERNEL);
  79        if (cb_buff->buffer.scan_mask == NULL) {
  80                ret = -ENOMEM;
  81                goto error_release_channels;
  82        }
  83        chan = &cb_buff->channels[0];
  84        while (chan->indio_dev) {
  85                if (chan->indio_dev != indio_dev) {
  86                        ret = -EINVAL;
  87                        goto error_free_scan_mask;
  88                }
  89                set_bit(chan->channel->scan_index,
  90                        cb_buff->buffer.scan_mask);
  91                chan++;
  92        }
  93
  94        return cb_buff;
  95
  96error_free_scan_mask:
  97        kfree(cb_buff->buffer.scan_mask);
  98error_release_channels:
  99        iio_channel_release_all(cb_buff->channels);
 100error_free_cb_buff:
 101        kfree(cb_buff);
 102        return ERR_PTR(ret);
 103}
 104EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
 105
 106int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
 107{
 108        return iio_update_buffers(cb_buff->channels[0].indio_dev,
 109                                  &cb_buff->buffer,
 110                                  NULL);
 111}
 112EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 113
 114void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
 115{
 116        iio_update_buffers(cb_buff->channels[0].indio_dev,
 117                           NULL,
 118                           &cb_buff->buffer);
 119}
 120EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 121
 122void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 123{
 124        iio_channel_release_all(cb_buff->channels);
 125        iio_buffer_put(&cb_buff->buffer);
 126}
 127EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 128
 129struct iio_channel
 130*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 131{
 132        return cb_buffer->channels;
 133}
 134EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
 135
 136MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 137MODULE_DESCRIPTION("Industrial I/O callback buffer");
 138MODULE_LICENSE("GPL");
 139