linux/drivers/iio/buffer/industrialio-buffer-cb.c
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   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/iio.h>
  14#include <linux/iio/buffer_impl.h>
  15#include <linux/iio/consumer.h>
  16
  17struct iio_cb_buffer {
  18        struct iio_buffer buffer;
  19        int (*cb)(const void *data, void *private);
  20        void *private;
  21        struct iio_channel *channels;
  22        struct iio_dev *indio_dev;
  23};
  24
  25static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
  26{
  27        return container_of(buffer, struct iio_cb_buffer, buffer);
  28}
  29
  30static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
  31{
  32        struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  33        return cb_buff->cb(data, cb_buff->private);
  34}
  35
  36static void iio_buffer_cb_release(struct iio_buffer *buffer)
  37{
  38        struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  39        kfree(cb_buff->buffer.scan_mask);
  40        kfree(cb_buff);
  41}
  42
  43static const struct iio_buffer_access_funcs iio_cb_access = {
  44        .store_to = &iio_buffer_cb_store_to,
  45        .release = &iio_buffer_cb_release,
  46
  47        .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
  48};
  49
  50struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
  51                                             int (*cb)(const void *data,
  52                                                       void *private),
  53                                             void *private)
  54{
  55        int ret;
  56        struct iio_cb_buffer *cb_buff;
  57        struct iio_channel *chan;
  58
  59        cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  60        if (cb_buff == NULL)
  61                return ERR_PTR(-ENOMEM);
  62
  63        iio_buffer_init(&cb_buff->buffer);
  64
  65        cb_buff->private = private;
  66        cb_buff->cb = cb;
  67        cb_buff->buffer.access = &iio_cb_access;
  68        INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  69
  70        cb_buff->channels = iio_channel_get_all(dev);
  71        if (IS_ERR(cb_buff->channels)) {
  72                ret = PTR_ERR(cb_buff->channels);
  73                goto error_free_cb_buff;
  74        }
  75
  76        cb_buff->indio_dev = cb_buff->channels[0].indio_dev;
  77        cb_buff->buffer.scan_mask
  78                = kcalloc(BITS_TO_LONGS(cb_buff->indio_dev->masklength),
  79                          sizeof(long), GFP_KERNEL);
  80        if (cb_buff->buffer.scan_mask == NULL) {
  81                ret = -ENOMEM;
  82                goto error_release_channels;
  83        }
  84        chan = &cb_buff->channels[0];
  85        while (chan->indio_dev) {
  86                if (chan->indio_dev != cb_buff->indio_dev) {
  87                        ret = -EINVAL;
  88                        goto error_free_scan_mask;
  89                }
  90                set_bit(chan->channel->scan_index,
  91                        cb_buff->buffer.scan_mask);
  92                chan++;
  93        }
  94
  95        return cb_buff;
  96
  97error_free_scan_mask:
  98        kfree(cb_buff->buffer.scan_mask);
  99error_release_channels:
 100        iio_channel_release_all(cb_buff->channels);
 101error_free_cb_buff:
 102        kfree(cb_buff);
 103        return ERR_PTR(ret);
 104}
 105EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
 106
 107int iio_channel_cb_set_buffer_watermark(struct iio_cb_buffer *cb_buff,
 108                                        size_t watermark)
 109{
 110        if (!watermark)
 111                return -EINVAL;
 112        cb_buff->buffer.watermark = watermark;
 113
 114        return 0;
 115}
 116EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
 117
 118int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
 119{
 120        return iio_update_buffers(cb_buff->indio_dev, &cb_buff->buffer,
 121                                  NULL);
 122}
 123EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 124
 125void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
 126{
 127        iio_update_buffers(cb_buff->indio_dev, NULL, &cb_buff->buffer);
 128}
 129EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 130
 131void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 132{
 133        iio_channel_release_all(cb_buff->channels);
 134        iio_buffer_put(&cb_buff->buffer);
 135}
 136EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 137
 138struct iio_channel
 139*iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 140{
 141        return cb_buffer->channels;
 142}
 143EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
 144
 145struct iio_dev
 146*iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
 147{
 148        return cb_buffer->indio_dev;
 149}
 150EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
 151
 152MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 153MODULE_DESCRIPTION("Industrial I/O callback buffer");
 154MODULE_LICENSE("GPL");
 155