greybus: audio: Register CPorts for specific directions

Currently, it is assumed that all audio data CPorts registered on
APB1 are used for transmitting audio data.  That may not always be
true like when a microphone is connected but no speakers.  Also,
the current special protocol lacks a way to tell APB1 whether the CPort
being registered is for transmitting, receiving, or both.

Fix by adding a 'direction' field to the register and unregister CPort
requests and define bits indicating which direction (or both) audio
data will go on that CPort.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/audio_apbridgea.c

@@ -29,13 +29,15 @@ int gb_audio_apbridgea_set_config(struct gb_connection *connection,
 EXPORT_SYMBOL_GPL(gb_audio_apbridgea_set_config);
 
 int gb_audio_apbridgea_register_cport(struct gb_connection *connection,
-				      __u16 i2s_port, __u16 cportid)
+				      __u16 i2s_port, __u16 cportid,
+				      __u8 direction)
 {
 	struct audio_apbridgea_register_cport_request req;
 
 	req.hdr.type = AUDIO_APBRIDGEA_TYPE_REGISTER_CPORT;
 	req.hdr.i2s_port = cpu_to_le16(i2s_port);
 	req.cport = cpu_to_le16(cportid);
+	req.direction = direction;
 
 	return gb_hd_output(connection->hd, &req, sizeof(req),
 			    GB_APB_REQUEST_AUDIO_CONTROL, true);
@@ -43,13 +45,15 @@ int gb_audio_apbridgea_register_cport(struct gb_connection *connection,
 EXPORT_SYMBOL_GPL(gb_audio_apbridgea_register_cport);
 
 int gb_audio_apbridgea_unregister_cport(struct gb_connection *connection,
-					__u16 i2s_port, __u16 cportid)
+					__u16 i2s_port, __u16 cportid,
+					__u8 direction)
 {
 	struct audio_apbridgea_unregister_cport_request req;
 
 	req.hdr.type = AUDIO_APBRIDGEA_TYPE_UNREGISTER_CPORT;
 	req.hdr.i2s_port = cpu_to_le16(i2s_port);
 	req.cport = cpu_to_le16(cportid);
+	req.direction = direction;
 
 	return gb_hd_output(connection->hd, &req, sizeof(req),
 			    GB_APB_REQUEST_AUDIO_CONTROL, true);

drivers/staging/greybus/audio_apbridgea.h

@@ -75,6 +75,9 @@
 #define AUDIO_APBRIDGEA_PCM_RATE_176400			BIT(11)
 #define AUDIO_APBRIDGEA_PCM_RATE_192000			BIT(12)
 
+#define AUDIO_APBRIDGEA_DIRECTION_TX			BIT(0)
+#define AUDIO_APBRIDGEA_DIRECTION_RX			BIT(1)
+
 /* The I2S port is passed in the 'index' parameter of the USB request */
 /* The CPort is passed in the 'value' parameter of the USB request */
 
@@ -94,11 +97,13 @@ struct audio_apbridgea_set_config_request {
 struct audio_apbridgea_register_cport_request {
 	struct audio_apbridgea_hdr	hdr;
 	__le16				cport;
+	__u8				direction;
 } __packed;
 
 struct audio_apbridgea_unregister_cport_request {
 	struct audio_apbridgea_hdr	hdr;
 	__le16				cport;
+	__u8				direction;
 } __packed;
 
 struct audio_apbridgea_set_tx_data_size_request {

drivers/staging/greybus/audio_codec.c

@@ -60,7 +60,8 @@ static int gbcodec_startup(struct snd_pcm_substream *substream,
 	i2s_port = 0;	/* fixed for now */
 	cportid = gb_dai->connection->hd_cport_id;
 	ret = gb_audio_apbridgea_register_cport(gb_dai->connection, i2s_port,
-						cportid);
+						cportid,
+						AUDIO_APBRIDGEA_DIRECTION_TX);
 	dev_dbg(dai->dev, "Register %s:%d DAI, ret:%d\n", dai->name, cportid,
 		ret);
 
@@ -117,7 +118,8 @@ static void gbcodec_shutdown(struct snd_pcm_substream *substream,
 	/* un register cport */
 	i2s_port = 0;	/* fixed for now */
 	ret = gb_audio_apbridgea_unregister_cport(gb_dai->connection, i2s_port,
-					gb_dai->connection->hd_cport_id);
+					gb_dai->connection->hd_cport_id,
+					AUDIO_APBRIDGEA_DIRECTION_TX);
 
 	dev_dbg(dai->dev, "Unregister %s:%d DAI, ret:%d\n", dai->name,
 		gb_dai->connection->hd_cport_id, ret);
@@ -495,7 +497,8 @@ static void gb_audio_cleanup(struct gbaudio_codec_info *gb)
 					 ret);
 			cportid = connection->hd_cport_id;
 			ret = gb_audio_apbridgea_unregister_cport(connection, 0,
-								  cportid);
+						cportid,
+						AUDIO_APBRIDGEA_DIRECTION_TX);
 			if (ret)
 				dev_info(dev, "%d:Failed during unregister cport\n",
 					 ret);

drivers/staging/greybus/audio_codec.h

@@ -198,9 +198,11 @@ extern int gb_audio_apbridgea_set_config(struct gb_connection *connection,
 					 __u16 i2s_port, __u32 format,
 					 __u32 rate, __u32 mclk_freq);
 extern int gb_audio_apbridgea_register_cport(struct gb_connection *connection,
-					     __u16 i2s_port, __u16 cportid);
+					     __u16 i2s_port, __u16 cportid,
+					     __u8 direction);
 extern int gb_audio_apbridgea_unregister_cport(struct gb_connection *connection,
-					       __u16 i2s_port, __u16 cportid);
+					       __u16 i2s_port, __u16 cportid,
+					       __u8 direction);
 extern int gb_audio_apbridgea_set_tx_data_size(struct gb_connection *connection,
 					       __u16 i2s_port, __u16 size);
 extern int gb_audio_apbridgea_get_tx_delay(struct gb_connection *connection,