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)(const void *data, void *private);
  11         void *private;
  12         struct iio_channel *channels;
  13 };
  14
  15 static struct iio_cb_buffer *buffer_to_cb_buffer(struct iio_buffer *buffer)
  16 {
  17         return container_of(buffer, struct iio_cb_buffer, buffer);
  18 }
  19
  20 static int iio_buffer_cb_store_to(struct iio_buffer *buffer, const void *data)
  21 {
  22         struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  23         return cb_buff->cb(data, cb_buff->private);
  24 }
  25
  26 static void iio_buffer_cb_release(struct iio_buffer *buffer)
  27 {
  28         struct iio_cb_buffer *cb_buff = buffer_to_cb_buffer(buffer);
  29         kfree(cb_buff->buffer.scan_mask);
  30         kfree(cb_buff);
  31 }
  32
  33 static const struct iio_buffer_access_funcs iio_cb_access = {
  34         .store_to = &iio_buffer_cb_store_to,
  35         .release = &iio_buffer_cb_release,
  36
  37         .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
  38 };
  39
  40 struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
  41                                              int (*cb)(const void *data,
  42                                                        void *private),
  43                                              void *private)
  44 {
  45         int ret;
  46         struct iio_cb_buffer *cb_buff;
  47         struct iio_dev *indio_dev;
  48         struct iio_channel *chan;
  49
  50         cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  51         if (cb_buff == NULL)
  52                 return ERR_PTR(-ENOMEM);
  53
  54         iio_buffer_init(&cb_buff->buffer);
  55
  56         cb_buff->private = private;
  57         cb_buff->cb = cb;
  58         cb_buff->buffer.access = &iio_cb_access;
  59         INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  60
  61         cb_buff->channels = iio_channel_get_all(dev);
  62         if (IS_ERR(cb_buff->channels)) {
  63                 ret = PTR_ERR(cb_buff->channels);
  64                 goto error_free_cb_buff;
  65         }
  66
  67         indio_dev = cb_buff->channels[0].indio_dev;
  68         cb_buff->buffer.scan_mask
  69                 = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
  70                           GFP_KERNEL);
  71         if (cb_buff->buffer.scan_mask == NULL) {
  72                 ret = -ENOMEM;
  73                 goto error_release_channels;
  74         }
  75         chan = &cb_buff->channels[0];
  76         while (chan->indio_dev) {
  77                 if (chan->indio_dev != indio_dev) {
  78                         ret = -EINVAL;
  79                         goto error_free_scan_mask;
  80                 }
  81                 set_bit(chan->channel->scan_index,
  82                         cb_buff->buffer.scan_mask);
  83                 chan++;
  84         }
  85
  86         return cb_buff;
  87
  88 error_free_scan_mask:
  89         kfree(cb_buff->buffer.scan_mask);
  90 error_release_channels:
  91         iio_channel_release_all(cb_buff->channels);
  92 error_free_cb_buff:
  93         kfree(cb_buff);
  94         return ERR_PTR(ret);
  95 }
  96 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
  97
  98 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
  99 {
 100         return iio_update_buffers(cb_buff->channels[0].indio_dev,
 101                                   &cb_buff->buffer,
 102                                   NULL);
 103 }
 104 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 105
 106 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
 107 {
 108         iio_update_buffers(cb_buff->channels[0].indio_dev,
 109                            NULL,
 110                            &cb_buff->buffer);
 111 }
 112 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 113
 114 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 115 {
 116         iio_channel_release_all(cb_buff->channels);
 117         iio_buffer_put(&cb_buff->buffer);
 118 }
 119 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 120
 121 struct iio_channel
 122 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 123 {
 124         return cb_buffer->channels;
 125 }
 126 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);