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/iio.h>
  14 #include <linux/iio/buffer_impl.h>
  15 #include <linux/iio/consumer.h>
  16
  17 struct 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
  25 static 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
  30 static 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
  36 static 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
  43 static 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
  50 struct 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
  97 error_free_scan_mask:
  98         kfree(cb_buff->buffer.scan_mask);
  99 error_release_channels:
 100         iio_channel_release_all(cb_buff->channels);
 101 error_free_cb_buff:
 102         kfree(cb_buff);
 103         return ERR_PTR(ret);
 104 }
 105 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
 106
 107 int 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 }
 116 EXPORT_SYMBOL_GPL(iio_channel_cb_set_buffer_watermark);
 117
 118 int 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 }
 123 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 124
 125 void 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 }
 129 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 130
 131 void 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 }
 136 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 137
 138 struct iio_channel
 139 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 140 {
 141         return cb_buffer->channels;
 142 }
 143 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);
 144
 145 struct iio_dev
 146 *iio_channel_cb_get_iio_dev(const struct iio_cb_buffer *cb_buffer)
 147 {
 148         return cb_buffer->indio_dev;
 149 }
 150 EXPORT_SYMBOL_GPL(iio_channel_cb_get_iio_dev);
 151
 152 MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
 153 MODULE_DESCRIPTION("Industrial I/O callback buffer");
 154 MODULE_LICENSE("GPL");