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(const char *name,
  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         cb_buff->private = private;
  45         cb_buff->cb = cb;
  46         cb_buff->buffer.access = &iio_cb_access;
  47         INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  48
  49         cb_buff->channels = iio_channel_get_all(name);
  50         if (IS_ERR(cb_buff->channels)) {
  51                 ret = PTR_ERR(cb_buff->channels);
  52                 goto error_free_cb_buff;
  53         }
  54
  55         indio_dev = cb_buff->channels[0].indio_dev;
  56         cb_buff->buffer.scan_mask
  57                 = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
  58                           GFP_KERNEL);
  59         if (cb_buff->buffer.scan_mask == NULL) {
  60                 ret = -ENOMEM;
  61                 goto error_release_channels;
  62         }
  63         chan = &cb_buff->channels[0];
  64         while (chan->indio_dev) {
  65                 if (chan->indio_dev != indio_dev) {
  66                         ret = -EINVAL;
  67                         goto error_release_channels;
  68                 }
  69                 set_bit(chan->channel->scan_index,
  70                         cb_buff->buffer.scan_mask);
  71                 chan++;
  72         }
  73
  74         return cb_buff;
  75
  76 error_release_channels:
  77         iio_channel_release_all(cb_buff->channels);
  78 error_free_cb_buff:
  79         kfree(cb_buff);
  80 error_ret:
  81         return ERR_PTR(ret);
  82 }
  83 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
  84
  85 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
  86 {
  87         return iio_update_buffers(cb_buff->channels[0].indio_dev,
  88                                   &cb_buff->buffer,
  89                                   NULL);
  90 }
  91 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
  92
  93 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
  94 {
  95         iio_update_buffers(cb_buff->channels[0].indio_dev,
  96                            NULL,
  97                            &cb_buff->buffer);
  98 }
  99 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 100
 101 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 102 {
 103         iio_channel_release_all(cb_buff->channels);
 104         kfree(cb_buff);
 105 }
 106 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 107
 108 struct iio_channel
 109 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 110 {
 111         return cb_buffer->channels;
 112 }
 113 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);