lib: lte_link_control: Add support for band list in LTE band lock

Added the CONFIG_LTE_LOCK_BAND_LIST Kconfig option for configuring
LTE band lock using a list of band numbers. This can be used
alone or combined with CONFIG_LTE_LOCK_BAND_MASK, which takes
a bit string of enabled bands.

Removed default value from the CONFIG_LTE_LOCK_BAND_MASK Kconfig
option. When LTE band lock is enabled using CONFIG_LTE_LOCK_BANDS,
also the bands need to be explicitly configured. It makes no sense
to have a default list of bands which are enabled.

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

Author: tokangas

doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst

@@ -430,7 +430,12 @@ Modem libraries
 
 * :ref:`lte_lc_readme` library:
 
-  * Added support for new PDN events :c:enumerator:`LTE_LC_EVT_PDN_SUSPENDED` and :c:enumerator:`LTE_LC_EVT_PDN_RESUMED`.
+  * Added:
+
+    * Support for new PDN events :c:enumerator:`LTE_LC_EVT_PDN_SUSPENDED` and :c:enumerator:`LTE_LC_EVT_PDN_RESUMED`.
+    * The :kconfig:option:`CONFIG_LTE_LOCK_BAND_LIST` Kconfig option to set bands for the LTE band lock using a comma-separated list of band numbers.
+
+  * Removed the default value for the :kconfig:option:`CONFIG_LTE_LOCK_BAND_MASK` Kconfig option.
 
 Multiprotocol Service Layer libraries
 -------------------------------------

lib/lte_link_control/Kconfig

@@ -114,16 +114,28 @@ config LTE_SHELL
 config LTE_LOCK_BANDS
 	bool "LTE band lock"
 	help
-	  Enable LTE band lock. Bands not enabled in LTE_LOCK_BAND_MASK
-	  are not used when this setting is enabled.
+	  Enable LTE band lock. Only configured bands are used when this setting is enabled.
+	  The allowed bands can be configured using the CONFIG_LTE_LOCK_BAND_MASK and
+	  CONFIG_LTE_LOCK_BAND_LIST options. If both are configured, the bands are combined
+	  from both options.
 
 if LTE_LOCK_BANDS
+
 config LTE_LOCK_BAND_MASK
 	string "LTE band lock mask bit string"
-	default "10000001000000001100"
 	help
-	  Bit string of enabled bands. LSB is band 1. Leading zeroes
-	  can be omitted. The maximum length is 88 characters.
+	  Bit string of enabled bands. LSB is band 1. Leading zeroes can be omitted.
+	  The maximum length is 88 characters, meaning this can be used with band numbers up to 88.
+
+config LTE_LOCK_BAND_LIST
+	string "LTE band list"
+	help
+	  List of enabled bands. Comma-separated list of band numbers.
+	  Can be used with all valid band numbers, including bands over 88.
+	  This is only supported by the following modem firmware:
+	  - mfw_nrf91x1 v2.0.3 or later
+	  - mfw_nrf9151-ntn
+
 endif # LTE_LOCK_BANDS
 
 config LTE_PLMN_SELECTION_OPTIMIZATION

lib/lte_link_control/lte_lc_modem_hooks.c

@@ -17,14 +17,22 @@
 LOG_MODULE_DECLARE(lte_lc, CONFIG_LTE_LINK_CONTROL_LOG_LEVEL);
 
 #if defined(CONFIG_LTE_LOCK_BANDS)
+BUILD_ASSERT(sizeof(CONFIG_LTE_LOCK_BAND_MASK) > 1 || sizeof(CONFIG_LTE_LOCK_BAND_LIST) > 1,
+	     "CONFIG_LTE_LOCK_BAND_MASK or CONFIG_LTE_LOCK_BAND_LIST must be set");
 static void band_lock_set(void)
 {
 	int err;
 
 	/* Set LTE band lock (volatile setting).
 	 * Has to be done every time before activating the modem.
 	 */
-	err = nrf_modem_at_printf("AT%%XBANDLOCK=2,\""CONFIG_LTE_LOCK_BAND_MASK "\"");
+	if (sizeof(CONFIG_LTE_LOCK_BAND_LIST) > 1) {
+		err = nrf_modem_at_printf("AT%%XBANDLOCK=2,\"" CONFIG_LTE_LOCK_BAND_MASK "\",\""
+					  CONFIG_LTE_LOCK_BAND_LIST "\"");
+	} else {
+		err = nrf_modem_at_printf("AT%%XBANDLOCK=2,\"" CONFIG_LTE_LOCK_BAND_MASK "\"");
+	}
+
 	if (err) {
 		LOG_ERR("Failed to lock LTE bands, err %d", err);
 	}