ALSA: pcm: add IEC958 channel status helper

Add a helper to create the IEC958 channel status from an ALSA
snd_pcm_runtime structure, taking account of the sample rate and
sample size.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviwed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/pcm_iec958.h b/include/sound/pcm_iec958.h
new file mode 100644
index 0000000..0eed397
--- /dev/null
+++ b/include/sound/pcm_iec958.h
@@ -0,0 +1,9 @@
+#ifndef __SOUND_PCM_IEC958_H
+#define __SOUND_PCM_IEC958_H
+
+#include <linux/types.h>
+
+int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
+	size_t len);
+
+#endif