power on gnss modem

Author: olalonde

drivers/modem/Kconfig.cellular

@@ -62,5 +62,9 @@ config MODEM_CELLULAR_NEW_BAUDRATE_DELAY
 	range 0 1000
 	default 100 if DT_HAS_U_BLOX_LARA_R6_ENABLED
 	default 300
+config MODEM_CELLULAR_POWER_ON_GNSS
+	bool "Power on the modem's GNSS module"
+	depends on DT_HAS_SIMCOM_A76XX_ENABLED
+	default false
 
 endif

drivers/modem/modem_cellular.c

@@ -2073,7 +2073,12 @@ MODEM_CHAT_SCRIPT_CMDS_DEFINE(simcom_a76xx_init_chat_script_cmds,
 			      MODEM_CHAT_SCRIPT_CMD_RESP_NONE("AT", 100),
 			      MODEM_CHAT_SCRIPT_CMD_RESP_NONE("AT", 100),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("ATE0", ok_match),
-			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CGNSSPWR=1", ok_match),
+			      #if CONFIG_MODEM_CELLULAR_POWER_ON_GNSS
+			      // Power on the GNSS module. 
+			      // We need to do this early, otherwise it does not work when
+			      // doing it later (e.g. from a user pipe).
+			      MODEM_CHAT_SCRIPT_CMD_RESP_MULT("AT+CGNSSPWR=1", allow_match),
+			      #endif
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CFUN=4", ok_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CMEE=1", ok_match),
 			      MODEM_CHAT_SCRIPT_CMD_RESP("AT+CREG=1", ok_match),