IIO: core: Modify scan element type

The current scan element type uses the following format:
  [be|le]:[s|u]bits/storagebits[>>shift].
To specify multiple elements in this type, added a repeat value.
So new format is:
  [be|le]:[s|u]bits/storagebitsXr[>>shift].
Here r is specifying how may times, real/storage bits are repeating.

When X is value is 0 or 1, then repeat value is not used in the format,
and it will be same as existing format.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/industrialio-buffer.c

@@ -150,6 +150,15 @@ static ssize_t iio_show_fixed_type(struct device *dev,
 		type = IIO_BE;
 #endif
 	}
+	if (this_attr->c->scan_type.repeat > 1)
+		return sprintf(buf, "%s:%c%d/%dX%d>>%u\n",
+		       iio_endian_prefix[type],
+		       this_attr->c->scan_type.sign,
+		       this_attr->c->scan_type.realbits,
+		       this_attr->c->scan_type.storagebits,
+		       this_attr->c->scan_type.repeat,
+		       this_attr->c->scan_type.shift);
+		else
 			return sprintf(buf, "%s:%c%d/%d>>%u\n",
 		       iio_endian_prefix[type],
 		       this_attr->c->scan_type.sign,
@@ -475,6 +484,10 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
 	for_each_set_bit(i, mask,
 			 indio_dev->masklength) {
 		ch = iio_find_channel_from_si(indio_dev, i);
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
 			length = ch->scan_type.storagebits / 8;
 		bytes = ALIGN(bytes, length);
 		bytes += length;
@@ -482,6 +495,10 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
 	if (timestamp) {
 		ch = iio_find_channel_from_si(indio_dev,
 					      indio_dev->scan_index_timestamp);
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
 			length = ch->scan_type.storagebits / 8;
 		bytes = ALIGN(bytes, length);
 		bytes += length;
@@ -959,7 +976,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 					       indio_dev->masklength,
 					       in_ind + 1);
 			ch = iio_find_channel_from_si(indio_dev, in_ind);
-			length = ch->scan_type.storagebits/8;
+			if (ch->scan_type.repeat > 1)
+				length = ch->scan_type.storagebits / 8 *
+					ch->scan_type.repeat;
+			else
+				length = ch->scan_type.storagebits / 8;
 			/* Make sure we are aligned */
 			in_loc += length;
 			if (in_loc % length)
@@ -971,7 +992,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 			goto error_clear_mux_table;
 		}
 		ch = iio_find_channel_from_si(indio_dev, in_ind);
-		length = ch->scan_type.storagebits/8;
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
+			length = ch->scan_type.storagebits / 8;
 		if (out_loc % length)
 			out_loc += length - out_loc % length;
 		if (in_loc % length)
@@ -992,7 +1017,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 		}
 		ch = iio_find_channel_from_si(indio_dev,
 			indio_dev->scan_index_timestamp);
-		length = ch->scan_type.storagebits/8;
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
+			length = ch->scan_type.storagebits / 8;
 		if (out_loc % length)
 			out_loc += length - out_loc % length;
 		if (in_loc % length)

include/linux/iio/iio.h

@@ -177,6 +177,12 @@ struct iio_event_spec {
  *			shift:		Shift right by this before masking out
  *					realbits.
  *			endianness:	little or big endian
+ *			repeat:		Number of times real/storage bits
+ *					repeats. When the repeat element is
+ *					more than 1, then the type element in
+ *					sysfs will show a repeat value.
+ *					Otherwise, the number of repetitions is
+ *					omitted.
  * @info_mask_separate: What information is to be exported that is specific to
  *			this channel.
  * @info_mask_shared_by_type: What information is to be exported that is shared
@@ -219,6 +225,7 @@ struct iio_chan_spec {
 		u8	realbits;
 		u8	storagebits;
 		u8	shift;
+		u8	repeat;
 		enum iio_endian endianness;
 	} scan_type;
 	long			info_mask_separate;