ASoC: SOF: ipc: channel map structures

This change adds stream map and channel map structures
used for channel re-routing and stream aggregation.
Signed-off-by: Slawomir Blauciak <slawomir.blauciak@linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191210004854.16845-5-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/sound/sof/channel_map.h

+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2019 Intel Corporation. All rights reserved.
+ */
+
+#ifndef __IPC_CHANNEL_MAP_H__
+#define __IPC_CHANNEL_MAP_H__
+
+#include <uapi/sound/sof/header.h>
+#include <sound/sof/header.h>
+
+/**
+ * \brief Channel map, specifies transformation of one-to-many or many-to-one.
+ *
+ * In case of one-to-many specifies how the output channels are computed out of
+ * a single source channel,
+ * in case of many-to-one specifies how a single target channel is computed
+ * from a multichannel input stream.
+ *
+ * Channel index specifies position of the channel in the stream on the 'one'
+ * side.
+ *
+ * Ext ID is the identifier of external part of the transformation. Depending
+ * on the context, it may be pipeline ID, dai ID, ...
+ *
+ * Channel mask describes which channels are taken into account on the "many"
+ * side. Bit[i] set to 1 means that i-th channel is used for computation
+ * (either as source or as a target).
+ *
+ * Channel mask is followed by array of coefficients in Q2.30 format,
+ * one per each channel set in the mask (left to right, LS bit set in the
+ * mask corresponds to ch_coeffs[0]).
+ */
+struct sof_ipc_channel_map {
+	uint32_t ch_index;
+	uint32_t ext_id;
+	uint32_t ch_mask;
+	uint32_t reserved;
+	int32_t ch_coeffs[0];
+} __packed;
+
+/**
+ * \brief Complete map for each channel of a multichannel stream.
+ *
+ * num_ch_map Specifies number of items in the ch_map.
+ * More than one transformation per a single channel is allowed (in case
+ * multiple external entities are transformed).
+ * A channel may be skipped in the transformation list, then it is filled
+ * with 0's by the transformation function.
+ */
+struct sof_ipc_stream_map {
+	struct sof_ipc_cmd_hdr hdr;
+	uint32_t num_ch_map;
+	uint32_t reserved[3];
+	struct sof_ipc_channel_map ch_map[0];
+} __packed;
+
+#endif /* __IPC_CHANNEL_MAP_H__ */