+static int rsnd_ssi_hw_params(struct rsnd_mod *mod,
+ struct rsnd_dai_stream *io,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
+ struct rsnd_ssi *ssi_parent = rsnd_ssi_parent(ssi);
+ int chan = params_channels(params);
+
+ /*
+ * Already working.
+ * It will happen if SSI has parent/child connection.
+ */
+ if (ssi->usrcnt) {
+ /*
+ * it is error if child <-> parent SSI uses
+ * different channels.
+ */
+ if (ssi->chan != chan)
+ return -EIO;
+ }
+
+ /* It will be removed on rsnd_ssi_hw_stop */
+ ssi->chan = chan;
+ if (ssi_parent)
+ return rsnd_ssi_hw_params(rsnd_mod_get(ssi_parent), io,
+ substream, params);
+
+ return 0;
+}
+