ALSA: firewire-lib: use union for directional parameters

Some parameters of struct amdtp_stream is dependent on direction.

This commit uses union for such parameters to distinguish from
common parameters.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 25 insertions, 10 deletions

diff --git a/sound/firewire/amdtp-stream.h b/sound/firewire/amdtp-stream.h
index e45de3eecfe3..1945ef59ab92 100644
--- a/sound/firewire/amdtp-stream.h
+++ b/sound/firewire/amdtp-stream.h
@@ -111,7 +111,31 @@ struct amdtp_stream {
 	int (*handle_packet)(struct amdtp_stream *s,
 			unsigned int payload_quadlets, unsigned int cycle,
 			unsigned int index);
-	unsigned int max_payload_length;
+	union {
+		struct {
+			unsigned int ctx_header_size;
+
+			// limit for payload of iso packet.
+			unsigned int max_payload_length;
+
+			// For quirks of CIP headers.
+			// Fixed interval of dbc between previos/current
+			// packets.
+			unsigned int dbc_interval;
+			// Indicate the value of dbc field in a first packet.
+			unsigned int first_dbc;
+		} tx;
+		struct {
+			// To calculate CIP data blocks and tstamp.
+			unsigned int transfer_delay;
+			unsigned int data_block_state;
+			unsigned int last_syt_offset;
+			unsigned int syt_offset_state;
+
+			// To generate CIP header.
+			unsigned int fdf;
+		} rx;
+	} ctx_data;
 
 	/* For CIP headers. */
 	unsigned int source_node_id_field;
@@ -119,19 +143,10 @@ struct amdtp_stream {
 	unsigned int data_block_counter;
 	unsigned int sph;
 	unsigned int fmt;
-	unsigned int fdf;
-	/* quirk: fixed interval of dbc between previos/current packets. */
-	unsigned int tx_dbc_interval;
-	/* quirk: indicate the value of dbc field in a first packet. */
-	unsigned int tx_first_dbc;
 
 	/* Internal flags. */
 	enum cip_sfc sfc;
 	unsigned int syt_interval;
-	unsigned int transfer_delay;
-	unsigned int data_block_state;
-	unsigned int last_syt_offset;
-	unsigned int syt_offset_state;
 
 	/* For a PCM substream processing. */
 	struct snd_pcm_substream *pcm;