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
  38 struct iio_cb_buffer *iio_channel_get_all_cb(struct device *dev,
  39                                              int (*cb)(const void *data,
  40                                                        void *private),
  41                                              void *private)
  42 {
  43         int ret;
  44         struct iio_cb_buffer *cb_buff;
  45         struct iio_dev *indio_dev;
  46         struct iio_channel *chan;
  47
  48         cb_buff = kzalloc(sizeof(*cb_buff), GFP_KERNEL);
  49         if (cb_buff == NULL)
  50                 return ERR_PTR(-ENOMEM);
  51
  52         iio_buffer_init(&cb_buff->buffer);
  53
  54         cb_buff->private = private;
  55         cb_buff->cb = cb;
  56         cb_buff->buffer.access = &iio_cb_access;
  57         INIT_LIST_HEAD(&cb_buff->buffer.demux_list);
  58
  59         cb_buff->channels = iio_channel_get_all(dev);
  60         if (IS_ERR(cb_buff->channels)) {
  61                 ret = PTR_ERR(cb_buff->channels);
  62                 goto error_free_cb_buff;
  63         }
  64
  65         indio_dev = cb_buff->channels[0].indio_dev;
  66         cb_buff->buffer.scan_mask
  67                 = kcalloc(BITS_TO_LONGS(indio_dev->masklength), sizeof(long),
  68                           GFP_KERNEL);
  69         if (cb_buff->buffer.scan_mask == NULL) {
  70                 ret = -ENOMEM;
  71                 goto error_release_channels;
  72         }
  73         chan = &cb_buff->channels[0];
  74         while (chan->indio_dev) {
  75                 if (chan->indio_dev != indio_dev) {
  76                         ret = -EINVAL;
  77                         goto error_free_scan_mask;
  78                 }
  79                 set_bit(chan->channel->scan_index,
  80                         cb_buff->buffer.scan_mask);
  81                 chan++;
  82         }
  83
  84         return cb_buff;
  85
  86 error_free_scan_mask:
  87         kfree(cb_buff->buffer.scan_mask);
  88 error_release_channels:
  89         iio_channel_release_all(cb_buff->channels);
  90 error_free_cb_buff:
  91         kfree(cb_buff);
  92         return ERR_PTR(ret);
  93 }
  94 EXPORT_SYMBOL_GPL(iio_channel_get_all_cb);
  95
  96 int iio_channel_start_all_cb(struct iio_cb_buffer *cb_buff)
  97 {
  98         return iio_update_buffers(cb_buff->channels[0].indio_dev,
  99                                   &cb_buff->buffer,
 100                                   NULL);
 101 }
 102 EXPORT_SYMBOL_GPL(iio_channel_start_all_cb);
 103
 104 void iio_channel_stop_all_cb(struct iio_cb_buffer *cb_buff)
 105 {
 106         iio_update_buffers(cb_buff->channels[0].indio_dev,
 107                            NULL,
 108                            &cb_buff->buffer);
 109 }
 110 EXPORT_SYMBOL_GPL(iio_channel_stop_all_cb);
 111
 112 void iio_channel_release_all_cb(struct iio_cb_buffer *cb_buff)
 113 {
 114         iio_channel_release_all(cb_buff->channels);
 115         iio_buffer_put(&cb_buff->buffer);
 116 }
 117 EXPORT_SYMBOL_GPL(iio_channel_release_all_cb);
 118
 119 struct iio_channel
 120 *iio_channel_cb_get_channels(const struct iio_cb_buffer *cb_buffer)
 121 {
 122         return cb_buffer->channels;
 123 }
 124 EXPORT_SYMBOL_GPL(iio_channel_cb_get_channels);