This implements the server role for the Audio Streaming for Hearing Aid
specification[1]. Includes basic ability to probe the ASHA GATT service,
as well as starting/stopping streaming.
[1] https://source.android.com/docs/core/connect/bluetooth/asha
---
Makefile.am | 3 +-
lib/uuid.h | 3 +
src/shared/asha.c | 368 ++++++++++++++++++++++++++++++++++++++++++++++
src/shared/asha.h | 64 ++++++++
4 files changed, 437 insertions(+), 1 deletion(-)
create mode 100644 src/shared/asha.c
create mode 100644 src/shared/asha.h
diff --git a/Makefile.am b/Makefile.am
index 05d02932f..3e6610017 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -238,7 +238,8 @@ shared_sources = src/shared/io.h src/shared/timeout.h \
src/shared/bass.h src/shared/bass.c \
src/shared/ccp.h src/shared/ccp.c \
src/shared/lc3.h src/shared/tty.h \
- src/shared/bap-defs.h
+ src/shared/bap-defs.h \
+ src/shared/asha.h src/shared/asha.c
if READLINE
shared_sources += src/shared/shell.c src/shared/shell.h
diff --git a/lib/uuid.h b/lib/uuid.h
index 8404b287e..479986f06 100644
--- a/lib/uuid.h
+++ b/lib/uuid.h
@@ -163,6 +163,9 @@ extern "C" {
#define BAA_SERVICE 0x1851
#define BAA_SERVICE_UUID "00001851-0000-1000-8000-00805f9b34fb"
+#define ASHA_SERVICE 0xFDF0
+#define ASHA_PROFILE_UUID "0000FDF0-0000-1000-8000-00805f9b34fb"
+
#define PAC_CONTEXT 0x2bcd
#define PAC_SUPPORTED_CONTEXT 0x2bce
diff --git a/src/shared/asha.c b/src/shared/asha.c
new file mode 100644
index 000000000..4817b93cd
--- /dev/null
+++ b/src/shared/asha.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ *
+ * BlueZ - Bluetooth protocol stack for Linux
+ *
+ * Copyright (C) 2024 Asymptotic Inc.
+ *
+ * Author: Arun Raghavan <[email protected]>
+ *
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
+#include <errno.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lib/bluetooth.h"
+#include "lib/uuid.h"
+
+#include "src/shared/util.h"
+#include "src/shared/att.h"
+#include "src/log.h"
+
+#include "src/shared/queue.h"
+#include "src/shared/gatt-db.h"
+#include "src/shared/gatt-client.h"
+
+#include "asha.h"
+
+/* We use strings instead of uint128_t to maintain readability */
+#define ASHA_CHRC_READ_ONLY_PROPERTIES_UUID "6333651e-c481-4a3e-9169-7c902aad37bb"
+#define ASHA_CHRC_AUDIO_CONTROL_POINT_UUID "f0d4de7e-4a88-476c-9d9f-1937b0996cc0"
+#define ASHA_CHRC_AUDIO_STATUS_UUID "38663f1a-e711-4cac-b641-326b56404837"
+#define ASHA_CHRC_VOLUME_UUID "00e4ca9e-ab14-41e4-8823-f9e70c7e91df"
+#define ASHA_CHRC_LE_PSM_OUT_UUID "2d410339-82b6-42aa-b34e-e2e01df8cc1a"
+
+struct bt_asha *bt_asha_new(void)
+{
+ struct bt_asha *asha;
+
+ asha = new0(struct bt_asha, 1);
+
+ return asha;
+}
+
+void bt_asha_reset(struct bt_asha *asha)
+{
+ if (asha->status_notify_id) {
+ bt_gatt_client_unregister_notify(asha->client,
+ asha->status_notify_id);
+ }
+
+ gatt_db_unref(asha->db);
+ asha->db = NULL;
+
+ bt_gatt_client_unref(asha->client);
+ asha->client = NULL;
+
+ asha->psm = 0;
+}
+
+void bt_asha_state_reset(struct bt_asha *asha)
+{
+ asha->state = ASHA_STOPPED;
+ asha->resume_id = 0;
+
+ asha->cb = NULL;
+ asha->cb_user_data = NULL;
+}
+
+void bt_asha_free(struct bt_asha *asha)
+{
+ gatt_db_unref(asha->db);
+ bt_gatt_client_unref(asha->client);
+ free(asha);
+}
+
+static void asha_acp_sent(bool success, uint8_t err, void *user_data)
+{
+ struct bt_asha *asha = user_data;
+
+ if (success) {
+ DBG("AudioControlPoint command successfully sent");
+ } else {
+ error("Failed to send AudioControlPoint command: %d", err);
+
+ if (asha->cb)
+ asha->cb(-1, asha->cb_user_data);
+
+ bt_asha_state_reset(asha);
+ }
+}
+
+static int asha_send_acp(struct bt_asha *asha, uint8_t *cmd,
+ unsigned int len, bt_asha_cb_t cb, void *user_data)
+{
+ if (!bt_gatt_client_write_value(asha->client, asha->acp_handle, cmd,
+ len, asha_acp_sent, asha, NULL)) {
+ error("Error writing ACP start");
+ return -1;
+ }
+
+ asha->cb = cb;
+ asha->cb_user_data = user_data;
+
+ return 0;
+}
+
+unsigned int bt_asha_start(struct bt_asha *asha, bt_asha_cb_t cb,
+ void *user_data)
+{
+ uint8_t acp_start_cmd[] = {
+ 0x01, /* START */
+ 0x01, /* G.722, 16 kHz */
+ 0, /* Unknown media type */
+ asha->volume, /* Volume */
+ 0, /* Other disconnected */
+ };
+ int ret;
+
+ if (asha->state != ASHA_STOPPED) {
+ error("ASHA device start failed. Bad state %d", asha->state);
+ return 0;
+ }
+
+ ret = asha_send_acp(asha, acp_start_cmd, sizeof(acp_start_cmd), cb,
+ user_data);
+ if (ret < 0)
+ return 0;
+
+ asha->state = ASHA_STARTING;
+
+ return (++asha->resume_id);
+}
+
+unsigned int bt_asha_stop(struct bt_asha *asha, bt_asha_cb_t cb,
+ void *user_data)
+{
+ uint8_t acp_stop_cmd[] = {
+ 0x02, /* STOP */
+ };
+ int ret;
+
+ if (asha->state != ASHA_STARTED)
+ return 0;
+
+ asha->state = ASHA_STOPPING;
+
+ ret = asha_send_acp(asha, acp_stop_cmd, sizeof(acp_stop_cmd), cb,
+ user_data);
+ if (ret < 0)
+ return 0;
+
+ return asha->resume_id;
+}
+
+bool bt_asha_set_volume(struct bt_asha *asha, int8_t volume)
+{
+ if (!bt_gatt_client_write_without_response(asha->client,
+ asha->volume_handle, false,
+ (const uint8_t *)&volume, 1)) {
+ error("Error writing volume");
+ return false;
+ }
+
+ asha->volume = volume;
+ return true;
+}
+
+static bool uuid_cmp(const char *uuid1, const bt_uuid_t *uuid2)
+{
+ bt_uuid_t lhs;
+
+ bt_string_to_uuid(&lhs, uuid1);
+
+ return bt_uuid_cmp(&lhs, uuid2) == 0;
+}
+
+static void read_psm(bool success,
+ uint8_t att_ecode,
+ const uint8_t *value,
+ uint16_t length,
+ void *user_data)
+{
+ struct bt_asha *asha = user_data;
+
+ if (!success) {
+ DBG("Reading PSM failed with ATT error: %u", att_ecode);
+ return;
+ }
+
+ if (length != 2) {
+ DBG("Reading PSM failed: unexpected length %u", length);
+ return;
+ }
+
+ asha->psm = get_le16(value);
+
+ DBG("Got PSM: %u", asha->psm);
+}
+
+static void read_rops(bool success,
+ uint8_t att_ecode,
+ const uint8_t *value,
+ uint16_t length,
+ void *user_data)
+{
+ struct bt_asha *asha = user_data;
+
+ if (!success) {
+ DBG("Reading ROPs failed with ATT error: %u", att_ecode);
+ return;
+ }
+
+ if (length != 17) {
+ DBG("Reading ROPs failed: unexpected length %u", length);
+ return;
+ }
+
+ if (value[0] != 0x01) {
+ DBG("Unexpected ASHA version: %u", value[0]);
+ return;
+ }
+
+ /* Device Capabilities */
+ asha->right_side = (value[1] & 0x1) != 0;
+ asha->binaural = (value[1] & 0x2) != 0;
+ asha->csis_supported = (value[1] & 0x4) != 0;
+ /* HiSyncId: 2 byte company id, 6 byte ID shared by left and right */
+ memcpy(asha->hisyncid, &value[2], 8);
+ /* FeatureMap */
+ asha->coc_streaming_supported = (value[10] & 0x1) != 0;
+ /* RenderDelay */
+ asha->render_delay = get_le16(&value[11]);
+ /* byte 13 & 14 are reserved */
+ /* Codec IDs */
+ asha->codec_ids = get_le16(&value[15]);
+
+ DBG("Got ROPS: side %u, binaural %u, csis: %u, delay %u, codecs: %u",
+ asha->right_side, asha->binaural, asha->csis_supported,
+ asha->render_delay, asha->codec_ids);
+}
+
+static void audio_status_register(uint16_t att_ecode, void *user_data)
+{
+ if (att_ecode)
+ DBG("AudioStatusPoint register failed 0x%04x", att_ecode);
+ else
+ DBG("AudioStatusPoint register succeeded");
+}
+
+static void audio_status_notify(uint16_t value_handle, const uint8_t *value,
+ uint16_t length, void *user_data)
+{
+ struct bt_asha *asha = user_data;
+ uint8_t status = *value;
+ /* Back these up to survive the reset paths */
+ bt_asha_cb_t cb = asha->cb;
+ bt_asha_cb_t cb_user_data = asha->cb_user_data;
+
+ if (asha->state == ASHA_STARTING) {
+ if (status == 0) {
+ asha->state = ASHA_STARTED;
+ DBG("ASHA start complete");
+ } else {
+ bt_asha_state_reset(asha);
+ DBG("ASHA start failed");
+ }
+ } else if (asha->state == ASHA_STOPPING) {
+ /* We reset our state, regardless */
+ bt_asha_state_reset(asha);
+ DBG("ASHA stop %s", status == 0 ? "complete" : "failed");
+ }
+
+ if (cb) {
+ cb(status, cb_user_data);
+ asha->cb = NULL;
+ asha->cb_user_data = NULL;
+ }
+}
+
+static void handle_characteristic(struct gatt_db_attribute *attr,
+ void *user_data)
+{
+ struct bt_asha *asha = user_data;
+ uint16_t value_handle;
+ bt_uuid_t uuid;
+ char uuid_str[MAX_LEN_UUID_STR];
+
+ if (!gatt_db_attribute_get_char_data(attr, NULL, &value_handle, NULL,
+ NULL, &uuid)) {
+ error("Failed to obtain characteristic data");
+ return;
+ }
+
+ bt_uuid_to_string(&uuid, uuid_str, sizeof(uuid_str));
+ if (uuid_cmp(ASHA_CHRC_LE_PSM_OUT_UUID, &uuid)) {
+ DBG("Got chrc %s/0x%x: LE_PSM_ID", uuid_str, value_handle);
+ if (!bt_gatt_client_read_value(asha->client, value_handle,
+ read_psm, asha, NULL))
+ DBG("Failed to send request to read battery level");
+ } else if (uuid_cmp(ASHA_CHRC_READ_ONLY_PROPERTIES_UUID, &uuid)) {
+ DBG("Got chrc %s/0x%x: READ_ONLY_PROPERTIES", uuid_str,
+ value_handle);
+ if (!bt_gatt_client_read_value(asha->client, value_handle,
+ read_rops, asha, NULL))
+ DBG("Failed to send request for readonly properties");
+ } else if (uuid_cmp(ASHA_CHRC_AUDIO_CONTROL_POINT_UUID, &uuid)) {
+ DBG("Got chrc %s/0x%x: AUDIO_CONTROL_POINT", uuid_str,
+ value_handle);
+ /* Store this for later writes */
+ asha->acp_handle = value_handle;
+ } else if (uuid_cmp(ASHA_CHRC_VOLUME_UUID, &uuid)) {
+ DBG("Got chrc %s/0x%x: VOLUME", uuid_str, value_handle);
+ /* Store this for later writes */
+ asha->volume_handle = value_handle;
+ } else if (uuid_cmp(ASHA_CHRC_AUDIO_STATUS_UUID, &uuid)) {
+ DBG("Got chrc %s/0x%x: AUDIO_STATUS", uuid_str, value_handle);
+ asha->status_notify_id =
+ bt_gatt_client_register_notify(asha->client,
+ value_handle, audio_status_register,
+ audio_status_notify, asha, NULL);
+ if (!asha->status_notify_id)
+ DBG("Failed to send request to notify AudioStatus");
+ } else {
+ DBG("Unsupported characteristic: %s", uuid_str);
+ }
+}
+
+static void foreach_asha_service(struct gatt_db_attribute *attr,
+ void *user_data)
+{
+ struct bt_asha *asha = user_data;
+
+ DBG("Found ASHA GATT service");
+
+ asha->attr = attr;
+ gatt_db_service_set_claimed(attr, true);
+ gatt_db_service_foreach_char(asha->attr, handle_characteristic, asha);
+}
+
+bool bt_asha_probe(struct bt_asha *asha, struct gatt_db *db,
+ struct bt_gatt_client *client)
+{
+ bt_uuid_t asha_uuid;
+
+ asha->db = gatt_db_ref(db);
+ asha->client = bt_gatt_client_clone(client);
+
+ bt_uuid16_create(&asha_uuid, ASHA_SERVICE);
+ gatt_db_foreach_service(db, &asha_uuid, foreach_asha_service, asha);
+
+ if (!asha->attr) {
+ error("ASHA attribute not found");
+ bt_asha_reset(asha);
+ return false;
+ }
+
+ return true;
+}
diff --git a/src/shared/asha.h b/src/shared/asha.h
new file mode 100644
index 000000000..9fe051d07
--- /dev/null
+++ b/src/shared/asha.h
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/*
+ *
+ * BlueZ - Bluetooth protocol stack for Linux
+ *
+ * Copyright (C) 2024 Asymptotic Inc.
+ *
+ * Author: Arun Raghavan <[email protected]>
+ *
+ *
+ */
+
+#
+
+#include <stdbool.h>
+#include <stdint.h>
+
+enum bt_asha_state_t {
+ ASHA_STOPPED = 0,
+ ASHA_STARTING,
+ ASHA_STARTED,
+ ASHA_STOPPING,
+};
+
+typedef void (*bt_asha_cb_t)(int status, void *data);
+
+struct bt_asha {
+ struct bt_gatt_client *client;
+ struct gatt_db *db;
+ struct gatt_db_attribute *attr;
+ uint16_t acp_handle;
+ uint16_t volume_handle;
+ unsigned int status_notify_id;
+
+ uint16_t psm;
+ bool right_side;
+ bool binaural;
+ bool csis_supported;
+ bool coc_streaming_supported;
+ uint8_t hisyncid[8];
+ uint16_t render_delay;
+ uint16_t codec_ids;
+ int8_t volume;
+
+ enum bt_asha_state_t state;
+ bt_asha_cb_t cb;
+ void *cb_user_data;
+ unsigned int resume_id;
+};
+
+struct bt_asha *bt_asha_new(void);
+void bt_asha_reset(struct bt_asha *asha);
+void bt_asha_state_reset(struct bt_asha *asha);
+void bt_asha_free(struct bt_asha *asha);
+
+unsigned int bt_asha_start(struct bt_asha *asha, bt_asha_cb_t cb,
+ void *user_data);
+unsigned int bt_asha_stop(struct bt_asha *asha, bt_asha_cb_t cb,
+ void *user_data);
+
+bool bt_asha_set_volume(struct bt_asha *asha, int8_t volume);
+
+bool bt_asha_probe(struct bt_asha *asha, struct gatt_db *db,
+ struct bt_gatt_client *client);
--
2.45.1