app: nrfcloud: Add GCI support to cellpos

Implement cell positioning similarly to Location library
meaning AT%NCELLMEAS will be done 1-3 times depending on
how many cells are requested and found in each attempt.
Implementation done by copying GCI parsing from lte_lc.

Signed-off-by: Tommi Rantanen <tommi.rantanen@nordicsemi.no>

Author: trantanen

app/Kconfig

@@ -248,6 +248,9 @@ config SM_GNSS
 config SM_NRF_CLOUD
 	bool "nRF Cloud support"
 	default y
+	depends on NRF_CLOUD
+	depends on NRF_CLOUD_COAP
+	depends on DATE_TIME
 	select EXPERIMENTAL
 
 if SM_NRF_CLOUD
@@ -261,6 +264,7 @@ endif # SM_NRF_CLOUD
 
 config SM_NRF_CLOUD_LOCATION
 	bool "nRF Cloud Location support"
+	default y
 	depends on SM_NRF_CLOUD
 	help
 	  Enable the nRF Cloud Location service for cloud-assisted geolocation.

app/prj.conf

@@ -95,7 +95,6 @@ CONFIG_SETTINGS_NVS=y
 CONFIG_NVS=y
 
 # nRF Cloud
-CONFIG_SM_NRF_CLOUD_LOCATION=y
 CONFIG_NRF_CLOUD=y
 CONFIG_NRF_CLOUD_COAP=y
 CONFIG_NRF_CLOUD_COAP_DOWNLOADS=n

app/src/sm_at_gnss.c

@@ -59,7 +59,13 @@ enum sm_gnss_operation {
 
 #if defined(CONFIG_NRF_CLOUD_AGNSS)
 static struct k_work agnss_req_work;
-#endif
+
+#if defined(CONFIG_SM_NRF_CLOUD_LOCATION)
+static K_SEM_DEFINE(agnss_ncellmeas_sem, 0, 1);
+static struct lte_lc_cells_info *agnss_net_info;
+#endif /* CONFIG_SM_NRF_CLOUD_LOCATION */
+#endif /* CONFIG_SM_NRF_CLOUD */
+
 #if defined(CONFIG_NRF_CLOUD_PGPS)
 static struct k_work pgps_req_work;
 static struct k_work pgps_coap_req_work;
@@ -317,13 +323,26 @@ static int read_agnss_req(struct nrf_modem_gnss_agnss_data_frame *req)
 #endif /* CONFIG_NRF_CLOUD_AGNSS || CONFIG_NRF_CLOUD_PGPS */
 
 #if defined(CONFIG_NRF_CLOUD_AGNSS)
+
+#if defined(CONFIG_SM_NRF_CLOUD_LOCATION)
+static void agnss_ncellmeas_done(struct lte_lc_cells_info *cell_data, void *ctx)
+{
+	ARG_UNUSED(ctx);
+	agnss_net_info = cell_data;
+	k_sem_give(&agnss_ncellmeas_sem);
+}
+#endif /* CONFIG_SM_NRF_CLOUD_LOCATION */
+
 static void agnss_requestor(struct k_work *)
 {
 	int err;
 	struct nrf_modem_gnss_agnss_data_frame req;
 	struct nrf_cloud_coap_agnss_request request = {
-		NRF_CLOUD_COAP_AGNSS_REQ_CUSTOM,
-		&req,
+		.type = NRF_CLOUD_COAP_AGNSS_REQ_CUSTOM,
+		.agnss_req = &req,
+		.net_info = NULL,
+		.filtered = false,
+		.mask_angle = 0,
 	};
 	char *agnss_rest_data_buf = calloc(1, NRF_CLOUD_AGNSS_MAX_DATA_SIZE);
 
@@ -339,20 +358,43 @@ static void agnss_requestor(struct k_work *)
 	}
 
 	struct nrf_cloud_coap_agnss_result result = {
-		agnss_rest_data_buf,
-		NRF_CLOUD_AGNSS_MAX_DATA_SIZE,
-		0
+		.buf = agnss_rest_data_buf,
+		.buf_sz = NRF_CLOUD_AGNSS_MAX_DATA_SIZE,
+		.agnss_sz = 0,
 	};
-	struct lte_lc_cells_info net_info = {0};
 
-	err = get_single_cell_info(&net_info.current_cell);
-	if (err) {
-		LOG_ERR("Failed to obtain single-cell cellular network information (%d).", err);
-		goto cleanup;
+#if defined(CONFIG_SM_NRF_CLOUD_LOCATION)
+	/* Start async ncellmeas and wait for the result via semaphore.
+	 * agnss_ncellmeas_done() is called from the AT monitor thread
+	 * (not sm_work_q) for the single-phase case, so giving the semaphore
+	 * does not deadlock this work item.
+	 */
+	struct lte_lc_cells_info *net_info = NULL;
+
+	err = sm_at_nrfcloud_ncellmeas_start(1, false, agnss_ncellmeas_done, NULL);
+	if (err == 0) {
+		/* We will wait for 5 seconds for NCELLMEAS to complete. */
+		k_sem_take(&agnss_ncellmeas_sem, K_SECONDS(5));
+		net_info = agnss_net_info;
+		agnss_net_info = NULL;
 	}
-	request.net_info = &net_info;
 
+	if (net_info != NULL && net_info->current_cell.id != LTE_LC_CELL_EUTRAN_ID_INVALID) {
+		request.net_info = net_info;
+	} else {
+		LOG_WRN("Requesting A-GNSS data without location assistance");
+		sm_at_nrfcloud_ncellmeas_cleanup(net_info);
+		net_info = NULL;
+	}
+#else
+	LOG_INF("Requesting A-GNSS data without location assistance "
+		"since CONFIG_SM_NRF_CLOUD_LOCATION is not defined");
+#endif
 	err = nrf_cloud_coap_agnss_data_get(&request, &result);
+#if defined(CONFIG_SM_NRF_CLOUD_LOCATION)
+	sm_at_nrfcloud_ncellmeas_cleanup(net_info);
+	net_info = NULL;
+#endif
 	if (err) {
 		LOG_ERR("Failed to request A-GNSS data via CoAP (%d).", err);
 		goto cleanup;