drivers/iio/buffer_cb.c

   1 #include <linux/kernel.h>
   2 #include <linux/slab.h>
   3 #include <linux/err.h>
   4 #include <linux/export.h>
   5 #include <linux/iio/buffer.h>
   6 #include <linux/iio/consumer.h>
   7
   8 struct iio_cb_buffer {
   9         struct iio_buffer buffer;
  10         int (*cb)(u8 *data, void *private);
  11         void *private;
  12         struct iio_channel *channels;
  13 };
  14
  15 static int iio_buffer_cb_store_to(struct iio_buffer *buffer, u8 *data)
  16 {
  17         struct iio_cb_buffer *cb_buff = container_of(buffer,
  18                                                      struct iio_cb_buffer,
  19                                                      buffer);
  20
  21         return cb_buff->cb(data, cb_buff->private);
  22 }
  23
  24 static struct iio_buffer_access_funcs iio_cb_access = {
  25         .store_to = &iio_buffer_cb_store_to,
  26 };
  27
  28 struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
  29                                              int (*cb)(u8 *data,
  30                                                        void *private),
  31                                              void *private)
  32 {
  33         int ret;
  34         struct iio_cb_buffer *cb_buff;
  35         struct iio_dev *indio_dev;
  36         struct iio_channel *chan;
  37
  38         cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  39         if (cb_buff == NULL) {
  40                 ret = -ENOMEM;
  41                 goto error_ret;
  42         }
  43
  44         iio_buffer_init(&cb_buff->buffer);
  45
  46         cb_buff->private = private;
  47         cb_buff->cb = cb;
  48         cb_buff->buffer.access = &iio_cb_access;
  49         INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  50
  51         cb_buff->channels = iio_channel_get_all(dev);
  52         if (IS_ERR(cb_buff->channels)) {
  53                 ret = PTR_ERR(cb_buff->channels);
  54                 goto error_free_cb_buff;
  55         }
  56
  57         indio_dev = cb_buff->channels[0].indio_dev;
  58         cb_buff->buffer.scan_mask
  59                 = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
  60                           GFP_KERNEL);
  61         if (cb_buff->buffer.scan_mask == NULL) {
  62                 ret = -ENOMEM;
  63                 goto error_release_channels;
  64         }
  65         chan = &cb_buff->channels[0];
  66         while (chan->indio_dev) {
  67                 if (chan->indio_dev != indio_dev) {
  68                         ret = -EINVAL;
  69                         goto error_free_scan_mask;
  70                 }
  71                 set_bit(chan->channel->scan_index,
  72                         cb_buff->buffer.scan_mask);
  73                 chan++;
  74         }
  75
  76         return cb_buff;
  77
  78 error_free_scan_mask:
  79         kfree(cb_buff->buffer.scan_mask);
  80 error_release_channels:
  81         iio_channel_release_all(cb_buff->channels);
  82 error_free_cb_buff:
  83         kfree(cb_buff);
  84 error_ret:
  85         return ERR_PTR(ret);
  86 }
  87 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
  88
  89 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
  90 {
  91         return iio_update_buffers(cb_buff->channels[0].indio_dev,
  92                                   &cb_buff->buffer,
  93                                   NULL);
  94 }
  95 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
  96
  97 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
  98 {
  99         iio_update_buffers(cb_buff->channels[0].indio_dev,
 100                            NULL,
 101                            &cb_buff->buffer);
 102 }
 103 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 104
 105 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 106 {
 107         kfree(cb_buff->buffer.scan_mask);
 108         iio_channel_release_all(cb_buff->channels);
 109         kfree(cb_buff);
 110 }
 111 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 112
 113 struct iio_channel
 114 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 115 {
 116         return cb_buffer->channels;
 117 }
 118 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);