Bluetooth: BAP: Shell: Add support for USB audio in

Add support for receiving audio data from e.g. a PC
over USB and LC3 encode it before sending it
on BAP audio streams.

This refactores the entire TX path, as it has moved
from only support the sine wave generator, to also
supporting USB.

The encoding and sending of data is now in it's own
thread, instead of relying on the system workqueue thread
and k_work items.

Several other refactors have taken place to reduce lines
of codec (such as the introduction of the bap_foreach_stream
function.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>

Author: Thalley

subsys/bluetooth/audio/shell/CMakeLists.txt

@@ -81,7 +81,7 @@ zephyr_library_sources_ifdef(
   CONFIG_BT_BAP_STREAM
   bap.c
   )
-if (CONFIG_BT_AUDIO_RX AND CONFIG_LIBLC3 AND CONFIG_USB_DEVICE_AUDIO)
+if (CONFIG_LIBLC3 AND CONFIG_USB_DEVICE_AUDIO)
 	zephyr_library_sources(bap_usb.c)
 endif()
 zephyr_library_sources_ifdef(

subsys/bluetooth/audio/shell/audio.h

@@ -48,7 +48,7 @@ ssize_t cap_initiator_pa_data_add(struct bt_data *data_array, const size_t data_
 #include <zephyr/bluetooth/audio/bap_lc3_preset.h>
 #include <zephyr/bluetooth/audio/cap.h>
 
-unsigned long bap_get_recv_stats_interval(void);
+unsigned long bap_get_stats_interval(void);
 
 #if defined(CONFIG_LIBLC3)
 #include "lc3.h"
@@ -61,7 +61,7 @@ unsigned long bap_get_recv_stats_interval(void);
 #define LC3_MAX_NUM_SAMPLES_STEREO (LC3_MAX_NUM_SAMPLES_MONO * 2U)
 #endif /* CONFIG_LIBLC3 */
 
-#define LOCATION BT_AUDIO_LOCATION_FRONT_LEFT | BT_AUDIO_LOCATION_FRONT_RIGHT
+#define LOCATION BT_AUDIO_LOCATION_FRONT_LEFT
 #define CONTEXT                                                                                    \
 	(BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED | BT_AUDIO_CONTEXT_TYPE_CONVERSATIONAL |                \
 	 BT_AUDIO_CONTEXT_TYPE_MEDIA |                                                             \
@@ -75,15 +75,6 @@ struct named_lc3_preset {
 	struct bt_bap_lc3_preset preset;
 };
 
-const struct named_lc3_preset *bap_get_named_preset(bool is_unicast, enum bt_audio_dir dir,
-						    const char *preset_arg);
-
-size_t bap_get_rx_streaming_cnt(void);
-int bap_usb_init(void);
-int bap_usb_add_frame_to_usb(enum bt_audio_location lc3_chan_allocation, const int16_t *frame,
-			     size_t frame_size, uint32_t ts);
-void bap_usb_clear_frames_to_usb(void);
-
 struct shell_stream {
 	struct bt_cap_stream stream;
 	struct bt_audio_codec_cfg codec_cfg;
@@ -106,11 +97,20 @@ struct shell_stream {
 			/* The uptime tick measured when stream was connected */
 			int64_t connected_at_ticks;
 			uint16_t seq_num;
-			struct k_work_delayable audio_send_work;
-			bool active;
 #if defined(CONFIG_LIBLC3)
 			atomic_t lc3_enqueue_cnt;
+			bool active;
+			size_t encoded_cnt;
 			size_t lc3_sdu_cnt;
+			lc3_encoder_mem_48k_t lc3_encoder_mem;
+			lc3_encoder_t lc3_encoder;
+#if defined(CONFIG_USB_DEVICE_AUDIO)
+			/* Indicates where to read left USB data in the ring buffer */
+			size_t left_read_idx;
+			/* Indicates where to read right USB data in the ring buffer */
+			size_t right_read_idx;
+			size_t right_ring_buf_fail_cnt;
+#endif /* CONFIG_USB_DEVICE_AUDIO */
 #endif /* CONFIG_LIBLC3 */
 		} tx;
 #endif /* CONFIG_BT_AUDIO_TX */
@@ -119,6 +119,7 @@ struct shell_stream {
 		struct {
 			struct bt_iso_recv_info last_info;
 			size_t empty_sdu_pkts;
+			size_t valid_sdu_pkts;
 			size_t lost_pkts;
 			size_t err_pkts;
 			size_t dup_psn;
@@ -134,6 +135,26 @@ struct shell_stream {
 	};
 };
 
+const struct named_lc3_preset *bap_get_named_preset(bool is_unicast, enum bt_audio_dir dir,
+						    const char *preset_arg);
+
+size_t bap_get_rx_streaming_cnt(void);
+size_t bap_get_tx_streaming_cnt(void);
+void bap_foreach_stream(void (*func)(struct shell_stream *sh_stream, void *data), void *data);
+
+int bap_usb_init(void);
+
+int bap_usb_add_frame_to_usb(enum bt_audio_location lc3_chan_allocation, const int16_t *frame,
+			     size_t frame_size, uint32_t ts);
+void bap_usb_clear_frames_to_usb(void);
+uint16_t get_next_seq_num(struct bt_bap_stream *bap_stream);
+struct shell_stream *shell_stream_from_bap_stream(struct bt_bap_stream *bap_stream);
+struct bt_bap_stream *bap_stream_from_shell_stream(struct shell_stream *sh_stream);
+bool bap_usb_can_get_full_sdu(struct shell_stream *sh_stream);
+void bap_usb_get_frame(struct shell_stream *sh_stream, enum bt_audio_location chan_alloc,
+		       int16_t buffer[]);
+size_t bap_usb_get_frame_size(const struct shell_stream *sh_stream);
+
 struct broadcast_source {
 	bool is_cap;
 	union {