lib: location: Use %NCELLMEAS for GNSS assistance network info

Changed GNSS assistance request to use %NCELLMEAS instead of
%XMONITOR, because %XMONITOR may return stale cell information
when modem is in PSM.

Signed-off-by: Tommi Kangas <[email protected]>

lib/location/CMakeLists.txt

@@ -9,9 +9,12 @@ zephyr_library_sources(location.c)
 zephyr_library_sources(location_core.c)
 zephyr_library_sources(location_utils.c)
 zephyr_library_sources_ifdef(CONFIG_LOCATION_METHOD_GNSS method_gnss.c)
-zephyr_library_sources_ifdef(CONFIG_LOCATION_METHOD_CELLULAR scan_cellular.c)
 zephyr_library_sources_ifdef(CONFIG_LOCATION_METHOD_WIFI scan_wifi.c)
 
+if(CONFIG_LOCATION_METHOD_CELLULAR OR CONFIG_LOCATION_METHOD_GNSS)
+zephyr_library_sources(scan_cellular.c)
+endif()
+
 if(CONFIG_LOCATION_METHOD_CELLULAR OR CONFIG_LOCATION_METHOD_WIFI)
 zephyr_library_sources(method_cloud_location.c)
 add_subdirectory(cloud_service)

lib/location/location_utils.c

@@ -55,74 +55,14 @@ bool location_utils_is_lte_available(void)
 	return is_active;
 }
 
-int location_utils_modem_params_read(struct location_utils_modem_params_info *modem_params)
-{
-	/* Parsed strings include double quotes */
-	char plmn_str[MODEM_PARAM_STR_MAX_LEN + 1] = { 0 };
-	char tac_str[MODEM_PARAM_STR_MAX_LEN + 1] = { 0 };
-	char cell_id_str[MODEM_PARAM_STR_MAX_LEN + 1] = { 0 };
-	int err = 0;
-
-	__ASSERT_NO_MSG(modem_params != NULL);
-
-	err = nrf_modem_at_scanf(
-		"AT%XMONITOR",
-		"%%XMONITOR: "
-		"%*d"                                 /* <reg_status>: ignored */
-		",%*[^,]"                             /* <full_name>: ignored */
-		",%*[^,]"                             /* <short_name>: ignored */
-		",%"L(MODEM_PARAM_STR_MAX_LEN)"[^,]"  /* <plmn> */
-		",%"L(MODEM_PARAM_STR_MAX_LEN)"[^,]"  /* <tac> */
-		",%*d"                                /* <AcT>: ignored */
-		",%*d"                                /* <band>: ignored */
-		",%"L(MODEM_PARAM_STR_MAX_LEN)"[^,]"  /* <cell_id> */
-		",%d",                                /* <phys_cell_id> */
-		plmn_str, tac_str, cell_id_str, &modem_params->phys_cell_id);
-
-	if (err <= 2) {
-		LOG_ERR("Cannot get modem parameters, err %d", err);
-	} else {
-		/* Indicate success to the caller with zero return value */
-		err = 0;
-
-		/* Read MNC and store as integer. The MNC starts as the fifth character
-		 * in the string, following double quote and three characters long MCC.
-		 */
-		modem_params->mnc = strtol(&plmn_str[4], NULL, 10);
-
-		/* Null-terminated MCC, read and store it. */
-		plmn_str[4] = '\0';
-
-		modem_params->mcc = strtol(plmn_str + 1, NULL, 10);
-
-		/* <tac> */
-		modem_params->tac = strtol(tac_str + 1, NULL, 16);
-
-		/* <cell_id> */
-		modem_params->cell_id = strtol(cell_id_str + 1, NULL, 16);
-
-		LOG_DBG("parsed modem parameters: "
-			"mcc %d, mnc %d, tac %d (string: %s), cell_id %d (string: %s) phys_cell_id %d",
-			modem_params->mcc, modem_params->mnc, modem_params->tac,
-			tac_str, modem_params->cell_id, cell_id_str,
-			modem_params->phys_cell_id);
-	}
-	return err;
-}
-
 #else /* CONFIG_NRF_MODEM_LIB */
 
 bool location_utils_is_lte_available(void)
 {
 	return false;
 }
 
-int location_utils_modem_params_read(struct location_utils_modem_params_info *modem_params)
-{
-	return 0;
-}
-
-#endif /* CONFIG_NRF_MODEM_LIB*/
+#endif /* CONFIG_NRF_MODEM_LIB */
 
 const char *location_utils_nrf_cloud_jwt_generate(void)
 {

lib/location/location_utils.h

@@ -9,24 +9,6 @@
 
 #include <modem/location.h>
 
-/** Modem parameters. */
-struct location_utils_modem_params_info {
-	/** Mobile Country Code. */
-	int mcc;
-
-	/** Mobile Network Code. */
-	int mnc;
-
-	/** E-UTRAN cell ID */
-	uint32_t cell_id;
-
-	/** Tracking area code. */
-	uint32_t tac;
-
-	/** Physical cell ID. */
-	uint16_t phys_cell_id;
-};
-
 /**
  * @brief Check if LTE networking is available.
  *
@@ -38,16 +20,6 @@ struct location_utils_modem_params_info {
  */
 bool location_utils_is_lte_available(void);
 
-/**
- * @brief Read modem parameters.
- *
- * @param[out] modem_params Context where parameters are filled.
- *
- * @retval true      If modem parameters were received successfully.
- * @retval false     If modem parameters were not received successfully.
- */
-int location_utils_modem_params_read(struct location_utils_modem_params_info *modem_params);
-
 /**
  * @brief Generate JWT buffer to be used for nRF Cloud REST API use.
  *

lib/location/method_cloud_location.c

@@ -65,13 +65,13 @@ static void method_cloud_location_positioning_work_fn(struct k_work *work)
 
 #if defined(CONFIG_LOCATION_METHOD_WIFI)
 	if (wifi_config != NULL) {
-		err = scan_wifi_start(&wifi_scan_ready);
+		scan_wifi_start(&wifi_scan_ready);
 	}
 #endif
 
 #if defined(CONFIG_LOCATION_METHOD_CELLULAR)
 	if (cell_config != NULL) {
-		err = scan_cellular_start(cell_config->cell_count);
+		scan_cellular_start(cell_config->cell_count, false);
 		scan_cellular_info = scan_cellular_results_get();
 	}
 #endif

lib/location/method_gnss.c

@@ -15,6 +15,7 @@
 #include "location_core.h"
 #include "location_utils.h"
 #if defined(CONFIG_NRF_CLOUD_AGPS)
+#include "scan_cellular.h"
 #include <net/nrf_cloud_rest.h>
 #include <net/nrf_cloud_agps.h>
 #include <stdlib.h>
@@ -289,19 +290,20 @@ static void method_gnss_nrf_cloud_agps_request(void)
 	};
 
 	struct lte_lc_cells_info net_info = {0};
-	struct location_utils_modem_params_info modem_params = { 0 };
+	struct lte_lc_cells_info *scan_results;
 
 	/* Get network info for the A-GPS location request. */
-	err = location_utils_modem_params_read(&modem_params);
-
-	if (err < 0) {
+	scan_cellular_start(0, true);
+	scan_results = scan_cellular_results_get();
+	if (scan_results == NULL) {
 		LOG_WRN("Requesting A-GPS data without location assistance");
 	} else {
-		net_info.current_cell.id = modem_params.cell_id;
-		net_info.current_cell.tac = modem_params.tac;
-		net_info.current_cell.mcc = modem_params.mcc;
-		net_info.current_cell.mnc = modem_params.mnc;
-		net_info.current_cell.phys_cell_id = modem_params.phys_cell_id;
+		net_info.current_cell.mcc = scan_results->current_cell.mcc;
+		net_info.current_cell.mnc = scan_results->current_cell.mnc;
+		net_info.current_cell.id = scan_results->current_cell.id;
+		net_info.current_cell.tac = scan_results->current_cell.tac;
+		net_info.current_cell.phys_cell_id = scan_results->current_cell.phys_cell_id;
+		net_info.current_cell.rsrp = scan_results->current_cell.rsrp;
 		request.net_info = &net_info;
 	}
 
@@ -1201,5 +1203,14 @@ int method_gnss_init(void)
 	method_gnss_modem_sleep_notif_subscribe(MIN_SLEEP_DURATION_FOR_STARTING_GNSS);
 #endif
 	lte_lc_register_handler(method_gnss_lte_ind_handler);
+
+#if !defined(CONFIG_LOCATION_METHOD_CELLULAR)
+	/* Cellular location method is disabled, but GNSS method uses the cellular scan
+	 * functionality for A-GNSS request. The module needs to be initialized explicitly, because
+	 * init is not called by core.
+	 */
+	scan_cellular_init();
+#endif
+
 	return 0;
 }

lib/location/scan_cellular.c

@@ -84,11 +84,11 @@ void scan_cellular_lte_ind_handler(const struct lte_lc_evt *const evt)
 	}
 }
 
-int scan_cellular_start(uint8_t cell_count)
+void scan_cellular_start(uint8_t cell_count, bool light_search)
 {
-	struct location_utils_modem_params_info modem_params = { 0 };
 	struct lte_lc_ncellmeas_params ncellmeas_params = {
-		.search_type = LTE_LC_NEIGHBOR_SEARCH_TYPE_EXTENDED_COMPLETE,
+		.search_type = light_search ? LTE_LC_NEIGHBOR_SEARCH_TYPE_EXTENDED_LIGHT :
+					      LTE_LC_NEIGHBOR_SEARCH_TYPE_EXTENDED_COMPLETE,
 		.gci_count = 0
 	};
 	int err;
@@ -103,26 +103,7 @@ int scan_cellular_start(uint8_t cell_count)
 
 	err = lte_lc_neighbor_cell_measurement(&ncellmeas_params);
 	if (err) {
-		LOG_WRN("Failed to initiate neighbor cell measurements: %d, "
-			"next: fallback to get modem parameters",
-			err);
-
-		/* Doing fallback to get only the mandatory items manually:
-		 * cell id, mcc, mnc and tac
-		 */
-		err = location_utils_modem_params_read(&modem_params);
-		if (err < 0) {
-			LOG_ERR("Could not obtain modem parameters");
-		} else {
-			memset(&scan_cellular_info, 0, sizeof(struct lte_lc_cells_info));
-
-			/* Filling only the mandatory parameters */
-			scan_cellular_info.current_cell.mcc = modem_params.mcc;
-			scan_cellular_info.current_cell.mnc = modem_params.mnc;
-			scan_cellular_info.current_cell.tac = modem_params.tac;
-			scan_cellular_info.current_cell.id = modem_params.cell_id;
-			scan_cellular_info.current_cell.phys_cell_id = modem_params.phys_cell_id;
-		}
+		LOG_ERR("Failed to initiate neighbor cell measurements: %d", err);
 		goto end;
 	}
 	err = k_sem_take(&scan_cellular_sem_ncellmeas_evt, K_FOREVER);
@@ -160,7 +141,6 @@ int scan_cellular_start(uint8_t cell_count)
 
 end:
 	running = false;
-	return err;
 }
 
 int scan_cellular_cancel(void)

lib/location/scan_cellular.h

@@ -10,7 +10,7 @@
 #include <modem/lte_lc.h>
 
 int scan_cellular_init(void);
-int scan_cellular_start(uint8_t cell_count);
+void scan_cellular_start(uint8_t cell_count, bool light_search);
 struct lte_lc_cells_info *scan_cellular_results_get(void);
 int scan_cellular_cancel(void);
 

lib/location/scan_wifi.c

@@ -46,7 +46,7 @@ struct wifi_scan_info *scan_wifi_results_get(void)
 	return &scan_wifi_info;
 }
 
-int scan_wifi_start(struct k_sem *wifi_scan_ready)
+void scan_wifi_start(struct k_sem *wifi_scan_ready)
 {
 	int ret;
 
@@ -64,7 +64,6 @@ int scan_wifi_start(struct k_sem *wifi_scan_ready)
 		k_sem_give(wifi_scan_ready);
 		wifi_scan_ready = NULL;
 	}
-	return ret;
 }
 
 static void scan_wifi_result_handle(struct net_mgmt_event_callback *cb)

lib/location/scan_wifi.h

@@ -10,7 +10,7 @@
 #include <net/wifi_location_common.h>
 
 int scan_wifi_init(void);
-int scan_wifi_start(struct k_sem *wifi_scan_ready);
+void scan_wifi_start(struct k_sem *wifi_scan_ready);
 struct wifi_scan_info *scan_wifi_results_get(void);
 int scan_wifi_cancel(void);