staging:iio: make iio_sw_buffer_preenable much more general.

Also introduces active_scan_mask storage to tell the core what is
really being currently captured from the device (different from
what is desired as often has bonus channels).

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/staging/iio/iio.h b/drivers/staging/iio/iio.h
index 4fb8f2f21a070db667cbc60f6255b9c427bbfc75..c22554245a625e255cff9c887092aefa03e0158b 100644 (file)
--- a/drivers/staging/iio/iio.h
+++ b/drivers/staging/iio/iio.h
@@ -280,6 +280,7 @@ struct iio_info {
  * @available_scan_masks: [DRIVER] optional array of allowed bitmasks
  * @masklength:                [INTERN] the length of the mask established from
  *                     channels
+ * @active_scan_mask:  [INTERN] union of all scan masks requested by buffers
  * @trig:              [INTERN] current device trigger (buffer modes)
  * @pollfunc:          [DRIVER] function run on trigger being received
  * @channels:          [DRIVER] channel specification structure table
@@ -307,6 +308,7 @@ struct iio_dev {
 
        unsigned long                   *available_scan_masks;
        unsigned                        masklength;
+       unsigned long                   *active_scan_mask;
        struct iio_trigger              *trig;
        struct iio_poll_func            *pollfunc;
 

diff --git a/drivers/staging/iio/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c
index b2cf3e33e39b2d27321c85131eead4d56509d3bd..e088a5c4ab59e584747e3e151fa9888287f3c039 100644 (file)
--- a/drivers/staging/iio/industrialio-buffer.c
+++ b/drivers/staging/iio/industrialio-buffer.c
@@ -531,32 +531,6 @@ ssize_t iio_buffer_show_enable(struct device *dev,
 }
 EXPORT_SYMBOL(iio_buffer_show_enable);
 
-int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
-{
-       struct iio_buffer *buffer = indio_dev->buffer;
-       size_t size;
-       dev_dbg(&indio_dev->dev, "%s\n", __func__);
-       /* Check if there are any scan elements enabled, if not fail*/
-       if (!(buffer->scan_count || buffer->scan_timestamp))
-               return -EINVAL;
-       if (buffer->scan_timestamp)
-               if (buffer->scan_count)
-                       /* Timestamp (aligned to s64) and data */
-                       size = (((buffer->scan_count * buffer->bpe)
-                                       + sizeof(s64) - 1)
-                               & ~(sizeof(s64) - 1))
-                               + sizeof(s64);
-               else /* Timestamp only  */
-                       size = sizeof(s64);
-       else /* Data only */
-               size = buffer->scan_count * buffer->bpe;
-       buffer->access->set_bytes_per_datum(buffer, size);
-
-       return 0;
-}
-EXPORT_SYMBOL(iio_sw_buffer_preenable);
-
-
 /* note NULL used as error indicator as it doesn't make sense. */
 static unsigned long *iio_scan_mask_match(unsigned long *av_masks,
                                          unsigned int masklength,
@@ -572,6 +546,43 @@ static unsigned long *iio_scan_mask_match(unsigned long *av_masks,
        return NULL;
 }
 
+int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
+{
+       struct iio_buffer *buffer = indio_dev->buffer;
+       const struct iio_chan_spec *ch;
+       unsigned bytes = 0;
+       int length, i;
+       dev_dbg(&indio_dev->dev, "%s\n", __func__);
+
+       /* How much space will the demuxed element take? */
+       for_each_set_bit(i, buffer->scan_mask,
+                        indio_dev->masklength) {
+               ch = iio_find_channel_from_si(indio_dev, i);
+               length = ch->scan_type.storagebits/8;
+               bytes = ALIGN(bytes, length);
+               bytes += length;
+       }
+       if (buffer->scan_timestamp) {
+               ch = iio_find_channel_from_si(indio_dev,
+                                             buffer->scan_index_timestamp);
+               length = ch->scan_type.storagebits/8;
+               bytes = ALIGN(bytes, length);
+               bytes += length;
+       }
+       buffer->access->set_bytes_per_datum(buffer, bytes);
+
+       /* What scan mask do we actually have ?*/
+       if (indio_dev->available_scan_masks)
+               indio_dev->active_scan_mask =
+                       iio_scan_mask_match(indio_dev->available_scan_masks,
+                                           indio_dev->masklength,
+                                           buffer->scan_mask);
+       else
+               indio_dev->active_scan_mask = buffer->scan_mask;
+       return 0;
+}
+EXPORT_SYMBOL(iio_sw_buffer_preenable);
+
 /**
  * iio_scan_mask_set() - set particular bit in the scan mask
  * @buffer: the buffer whose scan mask we are interested in