application: serial_lte_modem: Automatic LTE connection

applications/serial_lte_modem/Kconfig

@@ -8,16 +8,10 @@ source "Kconfig.zephyr"
 
 menu "Nordic Serial LTE Modem"
 
-config SLM_CUSTOMIZED
-	bool "Flag for customized functionality"
+config SLM_CUSTOMER_VERSION
+	string "Customer version string"
 	help
-	  Enable this flag to include customized logic.
-
-config SLM_AT_MODE
-	bool "Serial LTE Modem by raw AT mode"
-	default y
-	select AT_CMD_PARSER
-	select AT_MONITOR
+	   This version is reported together with baseline versions by AT command "#XSLMVER".
 
 config SLM_AT_MAX_PARAM
 	int "Maximum number of parameters in AT command"
@@ -104,15 +98,12 @@ config SLM_INDICATE_TIME
 	  GPIO active indication time in milliseconds. This setting specify the period length for the pin to be active
 
 #
-# Socket
+# LTE network automatic attach
 #
-config SLM_SOCKET_RX_MAX
-	int "Maximum RX buffer size for receiving socket data"
-	range 576 708
-	default 576
+config SLM_AUTO_CONNECT
+	bool "Automatically connect to the LTE network on start-up or after a reset"
 	help
-	  Default: NET_IPV4_MTU (576)
-	  Maximum: MSS setting in modem (708)
+	  Enables automatic connection to the LTE network using the PDN configuration defined in 'slm_auto_connect.h'.
 
 #
 # TCP/TLS proxy

applications/serial_lte_modem/doc/Generic_AT_commands.rst

@@ -32,11 +32,13 @@ Response syntax
 
 ::
 
-   #XSLMVER: <ncs_version>,<libmodem_version>
+   #XSLMVER: <ncs_version>,<libmodem_version>[,<customer_version>]
 
-The ``<ncs_version>`` value returns a string containing the version of the |NCS|.
+The ``<ncs_version>`` value is a string containing the version of the |NCS|.
 
-The ``<libmodem_version>`` value returns a string containing the version of the modem library.
+The ``<libmodem_version>`` value is a string containing the version of the modem library.
+
+The ``<customer_version>`` value is the :ref:`CONFIG_SLM_CUSTOMER_VERSION <CONFIG_SLM_CUSTOMER_VERSION>` string, if defined.
 
 Example
 ~~~~~~~
@@ -46,7 +48,11 @@ The following command example reads the versions:
 ::
 
    AT#XSLMVER
-   #XSLMVER: "2.3.0","2.3.0"
+   #XSLMVER: "2.5.0","2.5.0-lte-5ccd2d4dd54c"
+   OK
+
+   AT#XSLMVER
+   #XSLMVER: "2.5.99","2.5.0-lte-5ccd2d4dd54c","Onomondo 2.1.0"
    OK
 
 Read command

applications/serial_lte_modem/doc/slm_description.rst

@@ -43,11 +43,11 @@ Configuration options
 
 Check and configure the following configuration options for the sample:
 
-.. _CONFIG_SLM_CUSTOMIZED:
+.. _CONFIG_SLM_CUSTOMER_VERSION:
 
-CONFIG_SLM_CUSTOMIZED - Flag for customized functionality
-   This flag can be used to enable customized functionality.
-   To add your own custom logic, enclose the code by ``#if defined(CONFIG_SLM_CUSTOMIZED)`` and enable this flag.
+CONFIG_SLM_CUSTOMER_VERSION - Customer version string
+   Version string defined by the customer after customizing the application.
+   When defined, this version is reported with the baseline versions by the ``#XSLMVER`` AT command.
 
 .. _CONFIG_SLM_AT_MAX_PARAM:
 
@@ -124,14 +124,29 @@ CONFIG_SLM_INDICATE_TIME - Indicate GPIO active time
    This option specifies the length, in milliseconds, of the time interval during which the indicate GPIO must stay active.
    The default value is 100 milliseconds.
 
-.. _CONFIG_SLM_SOCKET_RX_MAX:
+.. _CONFIG_SLM_AUTO_CONNECT:
 
-CONFIG_SLM_SOCKET_RX_MAX - Maximum RX buffer size for receiving socket data
-   This option specifies the maximum buffer size for receiving data through the socket interface.
-   By default, this size is set to :c:enumerator:`NET_IPV4_MTU` (576), which is defined in Zephyr.
-   The maximum value is 708, which is the maximum segment size (MSS) defined for the modem.
+CONFIG_SLM_AUTO_CONNECT - Connect to LTE network at start-up or reset
+   This option enables connecting to the LTE network at start-up or reset using a defined PDN configuration.
+   This option is enabled by the LwM2M Carrier overlay, but is otherwise disabled by default.
 
-   This option impacts the total RAM usage.
+   .. note::
+      This option requires network-specific configuration in the ``slm_auto_connect.h`` file.
+
+   Here is a sample configuration for NIDD connection in the :file:`slm_auto_connect.h` file::
+
+      /* Network-specific default system mode configured by %XSYSTEMMODE (refer to AT command manual) */
+      0,        /* LTE support */
+      1,        /* NB-IoT support */
+      0,        /* GNSS support, also define CONFIG_MODEM_ANTENNA if not Nordic DK */
+      0,        /* LTE preference */
+      /* Network-specific default PDN configured by +CGDCONT and +CGAUTH (refer to AT command manual) */
+      true,     /* PDP context definition required or not */
+      "Non-IP", /* PDP type: "IP", "IPV6", "IPV4V6", "Non-IP" */
+      "",       /* Access point name */
+      0,        /* PDP authentication protocol: 0(None), 1(PAP), 2(CHAP) */
+      "",       /* PDN connection authentication username */
+      ""        /* PDN connection authentication password */
 
 .. _CONFIG_SLM_CR_TERMINATION:
 

applications/serial_lte_modem/overlay-carrier.conf

@@ -25,12 +25,7 @@ CONFIG_AT_HOST_LIBRARY=n
 # Credential management
 CONFIG_MODEM_KEY_MGMT=y
 
-# Non-volatile Storage
-CONFIG_NVS=y
-CONFIG_MPU_ALLOW_FLASH_WRITE=y
-
-# Default partition for NVS is unused
-CONFIG_PM_PARTITION_SIZE_NVS_STORAGE=0
-
 # Enable LwM2M carrier support in SLM
 CONFIG_SLM_CARRIER=y
+CONFIG_SLM_AUTO_CONNECT=y
+CONFIG_SLM_CUSTOMER_VERSION="lwm2m_carrier"

applications/serial_lte_modem/prj.conf

@@ -98,10 +98,14 @@ CONFIG_MODEM_JWT=y
 #CONFIG_MQTT_KEEPALIVE=60
 CONFIG_MQTT_CLEAN_SESSION=y
 
+# AT command helper libraries
+CONFIG_AT_CMD_PARSER=y
+CONFIG_AT_MONITOR=y
+
 #
 # SLM-specific configurations
 #
-CONFIG_SLM_CUSTOMIZED=n
+CONFIG_SLM_CUSTOMER_VERSION=""
 CONFIG_SLM_EXTERNAL_XTAL=n
 CONFIG_SLM_START_SLEEP=n
 CONFIG_SLM_DATAMODE_URC=n

applications/serial_lte_modem/src/lwm2m_carrier/slm_at_carrier.c

@@ -18,8 +18,6 @@ LOG_MODULE_REGISTER(slm_carrier, CONFIG_SLM_LOG_LEVEL);
 
 /**@brief LwM2M Carrier operations. */
 enum slm_carrier_operation {
-	/* LTE auto-connect operation for LwM2M Carrier */
-	CARRIER_OP_AUTO_CONNECT,
 	/* Carrier AppData Operation */
 	CARRIER_OP_APPDATA_SEND,
 	/* Carrier Device Operation */
@@ -60,7 +58,6 @@ struct carrier_op_list {
 static int m_mem_free;
 
 /** forward declaration of cmd handlers **/
-static int do_carrier_auto_connect(void);
 static int do_carrier_appdata_send(void);
 static int do_carrier_device_battery_level(void);
 static int do_carrier_device_battery_status(void);
@@ -84,7 +81,6 @@ static int do_carrier_request_link_up(void);
 
 /**@brief SLM AT Command list type. */
 static struct carrier_op_list op_list[CARRIER_OP_MAX] = {
-	{CARRIER_OP_AUTO_CONNECT, "auto_connect", do_carrier_auto_connect},
 	{CARRIER_OP_APPDATA_SEND, "app_data", do_carrier_appdata_send},
 	{CARRIER_OP_DEVICE_BATTERY_LEVEL, "battery_level", do_carrier_device_battery_level},
 	{CARRIER_OP_DEVICE_BATTERY_STATUS, "battery_status", do_carrier_device_battery_status},
@@ -839,37 +835,6 @@ static int do_carrier_request_link_up(void)
 	return lwm2m_carrier_request(LWM2M_CARRIER_REQUEST_LINK_UP);
 }
 
-/* AT#XCARRIER="auto_connect","read|write"[,<auto-connect-flag>] */
-static int do_carrier_auto_connect(void)
-{
-	int ret = 0;
-	int flag;
-	char operation[6];
-	size_t size = sizeof(operation);
-
-	ret = util_string_get(&slm_at_param_list, 2, operation, &size);
-	if (ret) {
-		return ret;
-	}
-
-	if (slm_util_cmd_casecmp(operation, "READ")) {
-		rsp_send("\r\n#XCARRIER: auto_connect %d\r\n", slm_carrier_auto_connect);
-	} else if (slm_util_cmd_casecmp(operation, "WRITE")) {
-		ret = at_params_int_get(&slm_at_param_list, 3, &flag);
-		if (ret) {
-			return ret;
-		}
-		if (flag == 0 || flag == 1) {
-			slm_carrier_auto_connect = flag;
-			(void)slm_settings_auto_connect_save();
-		} else {
-			ret = -EINVAL;
-		}
-	}
-
-	return ret;
-}
-
 /**@brief API to handle Carrier AT command
  */
 int handle_at_carrier(enum at_cmd_type cmd_type)

applications/serial_lte_modem/src/lwm2m_carrier/slm_at_carrier.h

@@ -14,10 +14,6 @@
  * @brief Vendor-specific AT command for LwM2M Carrier service.
  * @{
  */
-
-/* Whether to auto-connect to the network at startup or after a FOTA update. */
-extern int32_t slm_carrier_auto_connect;
-
 /**
  * @brief Initialize Carrier AT command parser.
  *

applications/serial_lte_modem/src/main.c

@@ -26,9 +26,7 @@
 #include "slm_at_fota.h"
 #include "slm_settings.h"
 #include "slm_uart_handler.h"
-#if defined(CONFIG_SLM_CARRIER)
-#include "slm_at_carrier.h"
-#endif
+#include "slm_util.h"
 
 LOG_MODULE_REGISTER(slm, CONFIG_SLM_LOG_LEVEL);
 
@@ -338,32 +336,59 @@ static void check_app_fota_status(void)
 int lte_auto_connect(void)
 {
 	int err = 0;
-
-#if defined(CONFIG_SLM_CARRIER)
+#if defined(CONFIG_SLM_AUTO_CONNECT)
 	int stat;
+	struct network_config {
+		/* Refer to AT command manual of %XSYSTEMMODE for system mode settings */
+		int lte_m_support;     /* 0 ~ 1 */
+		int nb_iot_support;    /* 0 ~ 1 */
+		int gnss_support;      /* 0 ~ 1 */
+		int lte_preference;    /* 0 ~ 4 */
+		/* Refer to AT command manual of +CGDCONT and +CGAUTH for PDN configuration */
+		bool pdp_config;       /* PDP context definition required or not */
+		char *pdn_fam;         /* PDP type: "IP", "IPV6", "IPV4V6", "Non-IP" */
+		char *pdn_apn;         /* Access point name */
+		int pdn_auth;          /* PDN authentication protocol 0(None), 1(PAP), 2(CHAP) */
+		char *pdn_username;    /* PDN connection authentication username */
+		char *pdn_password;    /* PDN connection authentication password */
+	};
+	const struct network_config cfg = {
+#include "slm_auto_connect.h"
+	};
 
-	if (!slm_carrier_auto_connect) {
-		return 0;
-	}
 	err = nrf_modem_at_scanf("AT+CEREG?", "+CEREG: %d", &stat);
 	if (err != 1 || (stat == 1 || stat == 5)) {
 		return 0;
 	}
 
-	LOG_INF("auto connect");
-#if defined(CONFIG_LWM2M_CARRIER_SERVER_BINDING_N)
-	err = nrf_modem_at_printf("AT%%XSYSTEMMODE=0,1,0,0");
+	LOG_INF("lte auto connect");
+	err = nrf_modem_at_printf("AT%%XSYSTEMMODE=%d,%d,%d,%d", cfg.lte_m_support,
+				  cfg.nb_iot_support, cfg.gnss_support, cfg.lte_preference);
 	if (err) {
-		LOG_ERR("Failed to configure RAT: %d", err);
+		LOG_ERR("Failed to configure system mode: %d", err);
 		return err;
 	}
-#endif /* CONFIG_LWM2M_CARRIER_SERVER_BINDING_N */
+	if (cfg.pdp_config) {
+		err = nrf_modem_at_printf("AT+CGDCONT=0,%s,%s", cfg.pdn_fam, cfg.pdn_apn);
+		if (err) {
+			LOG_ERR("Failed to configure PDN: %d", err);
+			return err;
+		}
+	}
+	if (cfg.pdp_config && cfg.pdn_auth != 0) {
+		err = nrf_modem_at_printf("AT+CGAUTH=0,%d,%s,%s", cfg.pdn_auth,
+					  cfg.pdn_username, cfg.pdn_password);
+		if (err) {
+			LOG_ERR("Failed to configure AUTH: %d", err);
+			return err;
+		}
+	}
 	err = nrf_modem_at_printf("AT+CFUN=1");
 	if (err) {
 		LOG_ERR("Failed to turn on radio: %d", err);
 		return err;
 	}
-#endif /* CONFIG_SLM_CARRIER */
+#endif /* CONFIG_SLM_AUTO_CONNECT */
 
 	return err;
 }

applications/serial_lte_modem/src/slm_at_commands.c

@@ -116,7 +116,14 @@ static int handle_at_slmver(enum at_cmd_type type)
 	if (type == AT_CMD_TYPE_SET_COMMAND) {
 		char *libmodem = nrf_modem_build_version();
 
-		rsp_send("\r\n#XSLMVER: %s,\"%s\"\r\n", STRINGIFY(NCS_VERSION_STRING), libmodem);
+		if (strlen(CONFIG_SLM_CUSTOMER_VERSION) > 0) {
+			rsp_send("\r\n#XSLMVER: %s,\"%s\",\"%s\"\r\n",
+				 STRINGIFY(NCS_VERSION_STRING), libmodem,
+				 CONFIG_SLM_CUSTOMER_VERSION);
+		} else {
+			rsp_send("\r\n#XSLMVER: %s,\"%s\"\r\n",
+				 STRINGIFY(NCS_VERSION_STRING), libmodem);
+		}
 		ret = 0;
 	}
 

applications/serial_lte_modem/src/slm_auto_connect.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/*
+ * This file defines the network configuration when CONFIG_SLM_AUTO_CONNECT is enabled.
+ */
+
+/* Network-specific default system mode configured by %XSYSTEMMODE (refer to AT command manual) */
+1,        /* LTE support */
+1,        /* NB-IoT support */
+1,        /* GNSS support, also define CONFIG_MODEM_ANTENNA if not Nordic DK */
+0,        /* LTE preference */
+/* Network-specific default PDN configured by +CGDCONT and +CGAUTH (refer to AT command manual) */
+false,    /* PDP context definition required or not */
+"",       /* PDP type: "IP", "IPV6", "IPV4V6", "Non-IP" */
+"",       /* Access point name */
+0,        /* PDP authentication protocol: 0(None), 1(PAP), 2(CHAP) */
+"",       /* PDN connection authentication username */
+""        /* PDN connection authentication password */