Bluetooth: ISO: extend API for setting SDU interval

The BT Core Spec v5.4 allows separate SDU_Interval to
be set on C_To_P and P_To_C directions,
but this is not possible with the existing interface.

This PR splits the interval parameter in the call to
bt_iso_sig_create into one for C_To_P
and one for P_To_C

It also splits the latency parameter into one for
C_To_P and one for P_To_C

Signed-off-by: Andries Kruithof <[email protected]>

Bluetooth: ISO: update UI for extended API

The API for setting the SDU interval and latency have been updated.
This PR also updates the setting of these by the user in the shell
and the iso_connected_benchmark sample

Signed-off-by: Andries Kruithof <[email protected]>

include/zephyr/bluetooth/iso.h

@@ -335,19 +335,33 @@ struct bt_iso_cig_param {
 	 */
 	uint8_t num_cis;
 
-	/** @brief Channel interval in us.
+	/** @brief Channel interval in us for SDUs sent from Central to Peripheral.
 	 *
 	 *  Value range BT_ISO_SDU_INTERVAL_MIN - BT_ISO_SDU_INTERVAL_MAX.
 	 */
-	uint32_t interval;
+	uint32_t c_to_p_interval;
 
-	/** @brief Channel Latency in ms.
+	/** @brief Channel interval in us for SDUs sent from Peripheral to Central.
+	 *
+	 *  Value range BT_ISO_SDU_INTERVAL_MIN - BT_ISO_SDU_INTERVAL_MAX.
+	 */
+	uint32_t p_to_c_interval;
+
+	/** @brief Channel Latency in ms for SDUs sent from Central to Peripheral
 	 *
 	 *  Value range BT_ISO_LATENCY_MIN - BT_ISO_LATENCY_MAX.
 	 *
 	 *  This value is ignored if any advanced ISO parameters are set.
 	 */
-	uint16_t latency;
+	uint16_t c_to_p_latency;
+
+	/** @brief Channel Latency in ms for SDUs sent from Peripheral to Central
+	 *
+	 *  Value range BT_ISO_LATENCY_MIN - BT_ISO_LATENCY_MAX.
+	 *
+	 *  This value is ignored if any advanced ISO parameters are set.
+	 */
+	uint16_t p_to_c_latency;
 
 	/** @brief Channel peripherals sleep clock accuracy Only for CIS
 	 *

samples/bluetooth/central_iso/src/main.c

@@ -25,6 +25,7 @@ static struct bt_conn *default_conn;
 static struct k_work_delayable iso_send_work;
 static struct bt_iso_chan iso_chan;
 static uint16_t seq_num;
+static uint16_t latency_ms = 10U; /* 10ms */
 static uint32_t interval_us = 10U * USEC_PER_MSEC; /* 10 ms */
 NET_BUF_POOL_FIXED_DEFINE(tx_pool, 1, BT_ISO_SDU_BUF_SIZE(CONFIG_BT_ISO_TX_MTU),
 			  CONFIG_BT_CONN_TX_USER_DATA_SIZE, NULL);
@@ -251,8 +252,10 @@ int main(void)
 	param.sca = BT_GAP_SCA_UNKNOWN;
 	param.packing = 0;
 	param.framing = 0;
-	param.latency = 10; /* ms */
-	param.interval = interval_us; /* us */
+	param.c_to_p_latency = latency_ms; /* ms */
+	param.p_to_c_latency = latency_ms; /* ms */
+	param.c_to_p_interval = interval_us; /* us */
+	param.p_to_c_interval = interval_us; /* us */
 
 	err = bt_iso_cig_create(&param, &cig);
 

samples/bluetooth/iso_connected_benchmark/src/main.c

@@ -28,6 +28,11 @@ enum benchmark_role {
 	ROLE_QUIT
 };
 
+enum sdu_dir {
+	DIR_C_TO_P,
+	DIR_P_TO_C
+};
+
 #define DEFAULT_CIS_RTN         2
 #define DEFAULT_CIS_INTERVAL_US 7500
 #define DEFAULT_CIS_LATENCY_MS  40
@@ -116,8 +121,10 @@ static struct bt_iso_chan_qos iso_qos = {
 };
 
 static struct bt_iso_cig_param cig_create_param = {
-	.interval = DEFAULT_CIS_INTERVAL_US, /* in microseconds */
-	.latency = DEFAULT_CIS_LATENCY_MS, /* milliseconds */
+	.c_to_p_interval = DEFAULT_CIS_INTERVAL_US, /* in microseconds */
+	.p_to_c_interval = DEFAULT_CIS_INTERVAL_US, /* in microseconds */
+	.c_to_p_latency = DEFAULT_CIS_LATENCY_MS, /* milliseconds */
+	.p_to_c_latency = DEFAULT_CIS_LATENCY_MS, /* milliseconds */
 	.sca = BT_GAP_SCA_UNKNOWN,
 	.packing = DEFAULT_CIS_PACKING,
 	.framing = DEFAULT_CIS_FRAMING,
@@ -179,17 +186,21 @@ static void iso_send(struct bt_iso_chan *chan)
 	int ret;
 	struct net_buf *buf;
 	struct iso_chan_work *chan_work;
+	uint32_t interval;
 
 	chan_work = CONTAINER_OF(chan, struct iso_chan_work, chan);
 
 	if (!chan_work->info.can_send) {
 		return;
 	}
 
+	interval = (role == ROLE_CENTRAL) ?
+		   cig_create_param.c_to_p_interval : cig_create_param.p_to_c_interval;
+
 	buf = net_buf_alloc(&tx_pool, K_FOREVER);
 	if (buf == NULL) {
 		LOG_ERR("Could not allocate buffer");
-		k_work_reschedule(&chan_work->send_work, K_USEC(cig_create_param.interval));
+		k_work_reschedule(&chan_work->send_work, K_USEC(interval));
 		return;
 	}
 
@@ -201,7 +212,7 @@ static void iso_send(struct bt_iso_chan *chan)
 	if (ret < 0) {
 		LOG_ERR("Unable to send data: %d", ret);
 		net_buf_unref(buf);
-		k_work_reschedule(&chan_work->send_work, K_USEC(cig_create_param.interval));
+		k_work_reschedule(&chan_work->send_work, K_USEC(interval));
 		return;
 	}
 
@@ -535,22 +546,25 @@ static int parse_rtn_arg(struct bt_iso_chan_io_qos *qos)
 	return (int)rtn;
 }
 
-static int parse_interval_arg(void)
+static int parse_interval_arg(enum sdu_dir direction)
 {
 	char buffer[9];
 	size_t char_count;
 	uint64_t interval;
 
-	printk("Set interval (us) (current %u, default %u)\n",
-	       cig_create_param.interval, DEFAULT_CIS_INTERVAL_US);
+	interval = (direction == DIR_C_TO_P) ?
+		   cig_create_param.c_to_p_interval : cig_create_param.p_to_c_interval;
+
+	printk("Set %s interval (us) (current %llu, default %u)\n",
+	       (direction == DIR_C_TO_P) ? "C to P" : "P to C",
+	       interval, DEFAULT_CIS_INTERVAL_US);
 
 	char_count = get_chars(buffer, sizeof(buffer) - 1);
 	if (char_count == 0) {
 		return DEFAULT_CIS_INTERVAL_US;
 	}
 
 	interval = strtoul(buffer, NULL, 0);
-	/* TODO: Replace literal ints with a #define once it has been created */
 	if (interval < BT_ISO_SDU_INTERVAL_MIN || interval > BT_ISO_SDU_INTERVAL_MAX) {
 		printk("Invalid interval %llu", interval);
 		return -EINVAL;
@@ -559,14 +573,18 @@ static int parse_interval_arg(void)
 	return (int)interval;
 }
 
-static int parse_latency_arg(void)
+static int parse_latency_arg(enum sdu_dir direction)
 {
 	char buffer[6];
 	size_t char_count;
 	uint64_t latency;
 
-	printk("Set latency (ms) (current %u, default %u)\n",
-	       cig_create_param.latency, DEFAULT_CIS_LATENCY_MS);
+	latency = (direction == DIR_C_TO_P) ?
+		  cig_create_param.c_to_p_latency : cig_create_param.p_to_c_latency;
+
+	printk("Set %s latency (ms) (current %llu, default %u)\n",
+	       (direction == DIR_C_TO_P) ? "C to P" : "P to C",
+	       latency, DEFAULT_CIS_LATENCY_MS);
 
 	char_count = get_chars(buffer, sizeof(buffer) - 1);
 	if (char_count == 0) {
@@ -805,8 +823,10 @@ static int parse_cis_count_arg(void)
 
 static int parse_cig_args(void)
 {
-	int interval;
-	int latency;
+	int c_to_p_interval;
+	int p_to_c_interval;
+	int c_to_p_latency;
+	int p_to_c_latency;
 	int cis_count;
 #if defined(CONFIG_BT_ISO_TEST_PARAMS)
 	int c_to_p_ft;
@@ -822,13 +842,23 @@ static int parse_cig_args(void)
 		return -EINVAL;
 	}
 
-	interval = parse_interval_arg();
-	if (interval < 0) {
+	c_to_p_interval = parse_interval_arg(DIR_C_TO_P);
+	if (c_to_p_interval < 0) {
+		return -EINVAL;
+	}
+
+	p_to_c_interval = parse_interval_arg(DIR_P_TO_C);
+	if (p_to_c_interval < 0) {
+		return -EINVAL;
+	}
+
+	c_to_p_latency = parse_latency_arg(DIR_C_TO_P);
+	if (c_to_p_latency < 0) {
 		return -EINVAL;
 	}
 
-	latency = parse_latency_arg();
-	if (latency < 0) {
+	p_to_c_latency = parse_latency_arg(DIR_P_TO_C);
+	if (p_to_c_latency < 0) {
 		return -EINVAL;
 	}
 
@@ -854,8 +884,10 @@ static int parse_cig_args(void)
 	}
 #endif /* CONFIG_BT_ISO_TEST_PARAMS */
 
-	cig_create_param.interval = interval;
-	cig_create_param.latency = latency;
+	cig_create_param.c_to_p_interval = c_to_p_interval;
+	cig_create_param.p_to_c_interval = p_to_c_interval;
+	cig_create_param.c_to_p_latency = c_to_p_latency;
+	cig_create_param.p_to_c_latency = p_to_c_latency;
 	cig_create_param.num_cis = cis_count;
 #if defined(CONFIG_BT_ISO_TEST_PARAMS)
 	cig_create_param.c_to_p_ft = c_to_p_ft;
@@ -923,9 +955,11 @@ static int change_central_settings(void)
 	int err;
 
 	printk("Change CIG settings (y/N)? (Current settings: cis_count=%u, "
-	       "interval=%u, latency=%u)\n",
-	       cig_create_param.num_cis, cig_create_param.interval,
-	       cig_create_param.latency);
+	       "C to P interval=%u, P to C interval=%u "
+	       "C to P latency=%u, P to C latency=%u)\n",
+	       cig_create_param.num_cis, cig_create_param.c_to_p_interval,
+	       cig_create_param.p_to_c_interval, cig_create_param.c_to_p_latency,
+	       cig_create_param.p_to_c_latency);
 
 	c = tolower(console_getchar());
 	if (c == 'y') {
@@ -934,9 +968,12 @@ static int change_central_settings(void)
 			return err;
 		}
 
-		printk("New settings: cis_count=%u, inteval=%u, latency=%u\n",
-		       cig_create_param.num_cis, cig_create_param.interval,
-		       cig_create_param.latency);
+		printk("New settings: cis_count=%u, C to P interval=%u, "
+		       "P TO C interval=%u, C to P latency=%u "
+		       "P TO C latency=%u\n",
+		       cig_create_param.num_cis, cig_create_param.c_to_p_interval,
+		       cig_create_param.p_to_c_interval, cig_create_param.c_to_p_latency,
+		       cig_create_param.p_to_c_latency);
 	}
 
 	printk("Change TX settings (y/N)? (Current settings: rtn=%u, "

subsys/bluetooth/audio/bap_unicast_client.c

@@ -2090,8 +2090,10 @@ static void bt_audio_codec_qos_to_cig_param(struct bt_iso_cig_param *cig_param,
 {
 	cig_param->framing = qos->framing;
 	cig_param->packing = BT_ISO_PACKING_SEQUENTIAL; /*  TODO: Add to QoS struct */
-	cig_param->interval = qos->interval;
-	cig_param->latency = qos->latency;
+	cig_param->c_to_p_interval = qos->interval;
+	cig_param->p_to_c_interval = qos->interval;
+	cig_param->c_to_p_latency = qos->latency;
+	cig_param->p_to_c_latency = qos->latency;
 	cig_param->sca = BT_GAP_SCA_UNKNOWN;
 
 	if (group_param != NULL) {

subsys/bluetooth/host/iso.c

@@ -1524,18 +1524,22 @@ static struct net_buf *hci_le_set_cig_params(const struct bt_iso_cig *cig,
 	memset(req, 0, sizeof(*req));
 
 	req->cig_id = cig->id;
-	req->c_latency = sys_cpu_to_le16(param->latency);
-	req->p_latency = sys_cpu_to_le16(param->latency);
-	sys_put_le24(param->interval, req->c_interval);
-	sys_put_le24(param->interval, req->p_interval);
+	req->c_latency = sys_cpu_to_le16(param->c_to_p_latency);
+	req->p_latency = sys_cpu_to_le16(param->p_to_c_latency);
+	sys_put_le24(param->c_to_p_interval, req->c_interval);
+	sys_put_le24(param->p_to_c_interval, req->p_interval);
 
 	req->sca = param->sca;
 	req->packing = param->packing;
 	req->framing = param->framing;
 	req->num_cis = param->num_cis;
 
-	LOG_DBG("id %u, latency %u, interval %u, sca %u, packing %u, framing %u, num_cis %u",
-		cig->id, param->latency, param->interval, param->sca, param->packing,
+	LOG_DBG("id %u, latency C to P %u, latency P to C %u, "
+		"interval C to P %u, interval P to C %u, "
+		"sca %u, packing %u, framing %u, num_cis %u",
+		cig->id, param->c_to_p_latency, param->p_to_c_latency,
+		param->c_to_p_interval, param->p_to_c_interval,
+		param->sca, param->packing,
 		param->framing, param->num_cis);
 
 	/* Program the cis parameters */
@@ -1611,8 +1615,8 @@ static struct net_buf *hci_le_set_cig_test_params(const struct bt_iso_cig *cig,
 	memset(req, 0, sizeof(*req));
 
 	req->cig_id = cig->id;
-	sys_put_le24(param->interval, req->c_interval);
-	sys_put_le24(param->interval, req->p_interval);
+	sys_put_le24(param->c_to_p_interval, req->c_interval);
+	sys_put_le24(param->p_to_c_interval, req->p_interval);
 
 	req->c_ft = param->c_to_p_ft;
 	req->p_ft = param->p_to_c_ft;
@@ -1622,10 +1626,10 @@ static struct net_buf *hci_le_set_cig_test_params(const struct bt_iso_cig *cig,
 	req->framing = param->framing;
 	req->num_cis = param->num_cis;
 
-	LOG_DBG("id %u, SDU interval %u, c_ft %u, p_ft %u, iso_interval %u, "
-		"sca %u, packing %u, framing %u, num_cis %u",
-		cig->id, param->interval, param->c_to_p_ft, param->p_to_c_ft,
-		param->iso_interval, param->sca, param->packing,
+	LOG_DBG("id %u, SDU interval C to P %u, SDU interval P to C %u, c_ft %u, p_ft %u, "
+		"iso_interval %u, sca %u, packing %u, framing %u, num_cis %u",
+		cig->id, param->c_to_p_interval, param->p_to_c_interval, param->c_to_p_ft,
+		param->p_to_c_ft, param->iso_interval, param->sca, param->packing,
 		param->framing, param->num_cis);
 
 	/* Program the cis parameters */
@@ -1859,16 +1863,28 @@ static bool valid_cig_param(const struct bt_iso_cig_param *param, bool advanced,
 		return false;
 	}
 
-	if (param->interval < BT_ISO_SDU_INTERVAL_MIN ||
-	    param->interval > BT_ISO_SDU_INTERVAL_MAX) {
-		LOG_DBG("Invalid interval: %u", param->interval);
+	if (param->c_to_p_interval < BT_ISO_SDU_INTERVAL_MIN ||
+	    param->c_to_p_interval > BT_ISO_SDU_INTERVAL_MAX) {
+		LOG_DBG("Invalid C to P interval: %u", param->c_to_p_interval);
+		return false;
+	}
+
+	if (param->p_to_c_interval < BT_ISO_SDU_INTERVAL_MIN ||
+	    param->p_to_c_interval > BT_ISO_SDU_INTERVAL_MAX) {
+		LOG_DBG("Invalid P to C interval: %u", param->p_to_c_interval);
 		return false;
 	}
 
 	if (!advanced &&
-	    (param->latency < BT_ISO_LATENCY_MIN ||
-	     param->latency > BT_ISO_LATENCY_MAX)) {
-		LOG_DBG("Invalid latency: %u", param->latency);
+	    (param->c_to_p_latency < BT_ISO_LATENCY_MIN ||
+	     param->c_to_p_latency > BT_ISO_LATENCY_MAX)) {
+		LOG_DBG("Invalid C to P latency: %u", param->c_to_p_latency);
+		return false;
+	}
+	if (!advanced &&
+	    (param->p_to_c_latency < BT_ISO_LATENCY_MIN ||
+	     param->p_to_c_latency > BT_ISO_LATENCY_MAX)) {
+		LOG_DBG("Invalid P to C latency: %u", param->p_to_c_latency);
 		return false;
 	}