linux/drivers/iio/buffer/industrialio-buffer-cb.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/* The industrial I/O callback buffer
   3 */
   4
   5#include <linux/kernel.h>
   6#include <linux/module.h>
   7#include <linux/slab.h>
   8#include <linux/err.h>
   9#include <linux/export.h>
  10#include <linux/iio/iio.h>
  11#include <linux/iio/buffer_impl.h>
  12#include <linux/iio/consumer.h>
  13
  14struct iio_cb_buffer {
  15        struct iio_buffer buffer;
  16        int (*cb)(const void *data, void *private);
  17        void *private;
  18        struct iio_channel *channels;
  19        struct iio_dev *indio_dev;
  20};
  21
  22static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
  23{
  24        return container_of(buffer, struct iio_cb_buffer, buffer);
  25}
  26
  27static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
  28{
  29        struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  30        return cb_buff->cb(data, cb_buff->private);
  31}
  32
  33static void iio_buffer_cb_release(struct iio_buffer *buffer)
  34{
  35        struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  36
  37        bitmap_free(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_channel *chan;
  56
  57        if (!cb) {
  58                dev_err(dev, "Invalid arguments: A callback must be provided!\n");
  59                return ERR_PTR(-EINVAL);
  60        }
  61
  62        cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  63        if (cb_buff == NULL)
  64                return ERR_PTR(-ENOMEM);
  65
  66        iio_buffer_init(&cb_buff->buffer);
  67
  68        cb_buff->private = private;
  69        cb_buff->cb = cb;
  70        cb_buff->buffer.access = &iio_cb_access;
  71        INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  72
  73        cb_buff->channels = iio_channel_get_all(dev);
  74        if (IS_ERR(cb_buff->channels)) {
  75                ret = PTR_ERR(cb_buff->channels);
  76                goto error_free_cb_buff;
  77        }
  78
  79        cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
  80        cb_buff->buffer.scan_mask = bitmap_zalloc(cb_buff->indio_dev->masklength,
  81                                                  GFP_KERNEL);
  82        if (cb_buff->buffer.scan_mask == NULL) {
  83                ret = -ENOMEM;
  84                goto error_release_channels;
  85        }
  86        chan = &cb_buff->channels[0];
  87        while (chan->indio_dev) {
  88                if (chan->indio_dev != cb_buff->indio_dev) {
  89                        ret = -EINVAL;
  90                        goto error_free_scan_mask;
  91                }
  92                set_bit(chan->channel->scan_index,
  93                        cb_buff->buffer.scan_mask);
  94                chan++;
  95        }
  96
  97        return cb_buff;
  98
  99error_free_scan_mask:
 100        bitmap_free(cb_buff->buffer.scan_mask);
 101error_release_channels:
 102        iio_channel_release_all(cb_buff->channels);
 103error_free_cb_buff:
 104        kfree(cb_buff);
 105        return ERR_PTR(ret);
 106}
 107EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
 108
 109int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
 110                                        size_t watermark)
 111{
 112        if (!watermark)
 113                return -EINVAL;
 114        cb_buff->buffer.watermark = watermark;
 115
 116        return 0;
 117}
 118EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
 119
 120int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
 121{
 122        return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
 123                                  NULL);
 124}
 125EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 126
 127void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
 128{
 129        iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
 130}
 131EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 132
 133void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 134{
 135        iio_channel_release_all(cb_buff->channels);
 136        iio_buffer_put(&cb_buff->buffer);
 137}
 138EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 139
 140struct iio_channel
 141*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 142{
 143        return cb_buffer->channels;
 144}
 145EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
 146
 147struct iio_dev
 148*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
 149{
 150        return cb_buffer->indio_dev;
 151}
 152EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
 153
 154MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 155MODULE_DESCRIPTION("Industrial I/O callback buffer");
 156MODULE_LICENSE("GPL");
 157