AT Host Refactoring for pipe based architecture

app/Kconfig

@@ -250,6 +250,15 @@ config SM_NRF_CLOUD
 	default y
 	select EXPERIMENTAL
 
+if SM_NRF_CLOUD
+config HEAP_MEM_POOL_ADD_SIZE_SM_NRF_CLOUD
+	int "Additional heap memory pool size for nRF Cloud support"
+	default 8192
+	help
+	  Some libraries used by nRF Cloud use System Heap (k_malloc() / k_free()) for
+	  dynamic memory allocation.
+endif # SM_NRF_CLOUD
+
 config SM_MQTTC
 	bool "MQTT client support"
 	default y
@@ -269,6 +278,15 @@ config SM_PPP
 config SM_CMUX
 	bool "CMUX support"
 
+config SM_CMUX_CHANNEL_COUNT
+	int "Number of CMUX channels"
+	depends on SM_CMUX
+	default 2
+	range 1 63
+	help
+	  Number of channels to be used by the CMUX implementation.
+	  Each channel adds about 4 kB of RAM usage for buffers.
+
 if SM_PPP
 
 config SM_PPP_FALLBACK_MTU
@@ -333,7 +351,7 @@ choice NRF_MODEM_LIB_TRACE_BACKEND
 
 config SM_MODEM_TRACE_BACKEND_CMUX
 	bool "CMUX modem trace backend"
-	depends on SM_CMUX
+	depends on SM_CMUX_CHANNEL_COUNT > 2
 	help
 	  When CMUX is enabled, modem traces are transmitted on a dedicated CMUX channel.
 	  The trace channel is the first channel after the AT command channel and the PPP channel.

app/overlay-trace-backend-cmux.conf

@@ -7,3 +7,4 @@
 # CMUX modem trace backend
 CONFIG_NRF_MODEM_LIB_TRACE=y
 CONFIG_SM_MODEM_TRACE_BACKEND_CMUX=y
+CONFIG_SM_CMUX_CHANNEL_COUNT=3

app/prj.conf

@@ -40,6 +40,11 @@ CONFIG_NET_IPV6=y
 CONFIG_NRF_MODEM_LIB=y
 CONFIG_AT_CMD_CUSTOM=y
 
+# Modem pipe
+CONFIG_MODEM_MODULES=y
+CONFIG_MODEM_PIPE=y
+CONFIG_MODEM_CMUX=y
+
 # Handle modem fault
 CONFIG_NRF_MODEM_LIB_ON_FAULT_APPLICATION_SPECIFIC=y
 
@@ -55,9 +60,10 @@ CONFIG_UART_INTERRUPT_DRIVEN=n
 
 # Stacks and heaps
 CONFIG_MAIN_STACK_SIZE=4096
-CONFIG_HEAP_MEM_POOL_SIZE=16384
 CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096
 CONFIG_AT_MONITOR_HEAP_SIZE=4096
+CONFIG_COMMON_LIBC_MALLOC=y
+CONFIG_COMMON_LIBC_MALLOC_ARENA_SIZE=-1
 
 # Device power management
 CONFIG_PM_DEVICE=y

app/scripts/sm_start_ppp.sh

@@ -143,6 +143,7 @@ noremoteip
 defaultroute
 defaultroute-metric -1
 lcp-echo-interval 0
+asyncmap 0xffffffff
 $PPP_DEBUG
 "
 

app/src/lwm2m_carrier/sm_at_carrier.c

@@ -54,8 +54,8 @@ static void print_err(const lwm2m_carrier_event_t *evt)
 
 	LOG_ERR("LWM2M_CARRIER_EVENT_ERROR: %s, reason %d", strerr[err->type], err->value);
 
-	rsp_send("\r\n#XCARRIEREVT: %u,%u,%d\r\n",
-		 LWM2M_CARRIER_EVENT_ERROR, err->type, err->value);
+	urc_send_to(sm_at_host_get_urc_pipe(), "\r\n#XCARRIEREVT: %u,%u,%d\r\n",
+		    LWM2M_CARRIER_EVENT_ERROR, err->type, err->value);
 }
 
 static void print_deferred(const lwm2m_carrier_event_t *evt)
@@ -91,8 +91,8 @@ static void print_deferred(const lwm2m_carrier_event_t *evt)
 	LOG_INF("LWM2M_CARRIER_EVENT_DEFERRED: reason %s, timeout %d seconds",
 		strdef[def->reason], def->timeout);
 
-	rsp_send("\r\n#XCARRIEREVT: %u,%u,%d\r\n",
-		 LWM2M_CARRIER_EVENT_DEFERRED, def->reason, def->timeout);
+	urc_send_to(sm_at_host_get_urc_pipe(), "\r\n#XCARRIEREVT: %u,%u,%d\r\n",
+		    LWM2M_CARRIER_EVENT_DEFERRED, def->reason, def->timeout);
 }
 
 static void on_event_app_data(const lwm2m_carrier_event_t *event)
@@ -129,13 +129,15 @@ static void on_event_app_data(const lwm2m_carrier_event_t *event)
 			return;
 		}
 
-		rsp_send("\r\n#XCARRIEREVT: %u,%hhu,\"%s\",%zu\r\n\"", event->type, app_data->type,
-			 uri_path, size);
-		data_send(sm_data_buf, size);
-		rsp_send("\"");
+		struct modem_pipe *pipe = sm_at_host_get_urc_pipe();
+
+		urc_send_to(pipe, "\r\n#XCARRIEREVT: %u,%hhu,\"%s\",%zu\r\n\"", event->type,
+			    app_data->type, uri_path, size);
+		data_send(pipe, sm_data_buf, size);
+		urc_send_to(pipe, "\"");
 	} else {
-		rsp_send("\r\n#XCARRIEREVT: %u,%hhu,\"%s\"\r\n", event->type, app_data->type,
-			 uri_path);
+		urc_send_to(sm_at_host_get_urc_pipe(), "\r\n#XCARRIEREVT: %u,%hhu,\"%s\"\r\n",
+			    event->type, app_data->type, uri_path);
 	}
 }
 
@@ -235,7 +237,7 @@ int lwm2m_carrier_event_handler(const lwm2m_carrier_event_t *event)
 		return 0;
 	}
 
-	rsp_send("\r\n#XCARRIEREVT: %d,%d\r\n", event->type, err);
+	urc_send_to(sm_at_host_get_urc_pipe(), "\r\n#XCARRIEREVT: %d,%d\r\n", event->type, err);
 
 #if defined(CONFIG_SM_CARRIER_AUTO_CONTROL)
 	/* Allow time for the URC be flushed before reboot */

app/src/main.c

@@ -44,15 +44,16 @@ static struct nrf_modem_fault_info modem_fault_info;
 static void on_modem_failure(struct k_work *)
 {
 	int ret;
+	struct modem_pipe *pipe = sm_at_host_get_urc_pipe();
 
-	rsp_send("\r\n#XMODEM: FAULT,0x%x,0x%x\r\n", modem_fault_info.reason,
-		 modem_fault_info.program_counter);
+	urc_send_to(pipe, "\r\n#XMODEM: FAULT,0x%x,0x%x\r\n", modem_fault_info.reason,
+		    modem_fault_info.program_counter);
 
 	ret = nrf_modem_lib_shutdown();
-	rsp_send("\r\n#XMODEM: SHUTDOWN,%d\r\n", ret);
+	urc_send_to(pipe, "\r\n#XMODEM: SHUTDOWN,%d\r\n", ret);
 
 	ret = nrf_modem_lib_init();
-	rsp_send("\r\n#XMODEM: INIT,%d\r\n", ret);
+	urc_send_to(pipe, "\r\n#XMODEM: INIT,%d\r\n", ret);
 }
 K_WORK_DEFINE(modem_failure_work, on_modem_failure);
 
@@ -144,17 +145,7 @@ static int bootloader_mode_init(void)
 	}
 	LOG_INF("Bootloader mode initiated successfully");
 
-	ret = sm_at_host_bootloader_init();
-	if (ret) {
-		LOG_ERR("Failed to init at_host: %d", ret);
-		return ret;
-	}
-
-	ret = sm_at_send_str("Bootloader mode ready\r\n");
-	if (ret) {
-		LOG_ERR("Failed to send bootloader mode ready string: %d", ret);
-		return ret;
-	}
+	urc_send("Bootloader mode ready\r\n");
 
 	sm_bootloader_mode_enabled = true;
 
@@ -257,12 +248,6 @@ static int sm_main(void)
 		}
 	}
 
-	ret = sm_uart_handler_enable();
-	if (ret) {
-		LOG_ERR("Failed to enable UART handler (%d).", ret);
-		return ret;
-	}
-
 #if defined(CONFIG_SM_FULL_FOTA)
 	if (sm_modem_full_fota) {
 		sm_finish_modem_full_fota();
@@ -287,13 +272,9 @@ static int sm_main(void)
 	check_app_fota_status();
 
 	if (sm_init_failed) {
-		ret = sm_at_send_str(SM_SYNC_ERR_STR);
+		urc_send(SM_SYNC_ERR_STR);
 	} else {
-		ret = sm_at_send_str(SM_SYNC_STR);
-	}
-
-	if (ret) {
-		return ret;
+		urc_send(SM_SYNC_STR);
 	}
 
 	/* This is here and not earlier because in case of firmware

app/src/sm_at_commands.c

@@ -267,10 +267,15 @@ STATIC int handle_at_clac(enum at_parser_cmd_type cmd_type, struct at_parser *,
 		const char *cmd = _nrf_modem_at_cmd_custom_list_start[i].cmd;
 		/* Modem AT commands start with 'AT+' or AT%. Other commands are
 		 * Serial Modem specific'. Skip modem AT commands.
-		 * Exception: AT+IPR is implemented in Serial Modem.
+		 * Exceptions that are implemented in Serial Modem:
+		 *	* AT+IPR
+		 *	* AT+CMUX
+		 *	* AT+CGDATA
 		 */
 		if ((strncasecmp(cmd, "AT+", strlen("AT+")) == 0 &&
-		     strncasecmp(cmd, "AT+IPR", strlen("AT+IPR")) != 0) ||
+		     strncasecmp(cmd, "AT+IPR", strlen("AT+IPR")) != 0 &&
+		     strncasecmp(cmd, "AT+CMUX", strlen("AT+CMUX")) != 0 &&
+		     strncasecmp(cmd, "AT+CGDATA", strlen("AT+CGDATA")) != 0) ||
 		    strncasecmp(cmd, "AT%%", strlen("AT%%")) == 0) {
 			continue;
 		}

app/src/sm_at_fota.c

@@ -56,6 +56,7 @@ int32_t sm_fota_info;
 
 static char path[FILE_URI_MAX];
 static char hostname[URI_HOST_MAX];
+static struct modem_pipe *fota_pipe;
 
 #if defined(CONFIG_SM_FULL_FOTA)
 /* Buffer used as temporary storage when downloading the modem firmware.
@@ -287,7 +288,7 @@ static void fota_dl_handler(const struct fota_download_evt *evt)
 		sm_fota_stage = FOTA_STAGE_DOWNLOAD;
 		sm_fota_status = FOTA_STATUS_OK;
 		sm_fota_info = evt->progress;
-		rsp_send("\r\n#XFOTA: %d,%d,%d\r\n",
+		urc_send_to(fota_pipe, "\r\n#XFOTA: %d,%d,%d\r\n",
 			sm_fota_stage, sm_fota_status, sm_fota_info);
 		break;
 	case FOTA_DOWNLOAD_EVT_FINISHED:
@@ -296,17 +297,18 @@ static void fota_dl_handler(const struct fota_download_evt *evt)
 		sm_modem_full_fota = (sm_fota_type == DFU_TARGET_IMAGE_TYPE_FULL_MODEM);
 		/* Save, in case reboot by reset */
 		sm_settings_fota_save();
-		rsp_send("\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
+		urc_send_to(fota_pipe, "\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
 		break;
 	case FOTA_DOWNLOAD_EVT_ERASE_TIMEOUT:
 		LOG_INF("Erasure timeout reached. Erasure continues.");
 		break;
 	case FOTA_DOWNLOAD_EVT_ERASE_PENDING:
 		sm_fota_stage = FOTA_STAGE_DOWNLOAD_ERASE_PENDING;
-		rsp_send("\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
+		urc_send_to(fota_pipe, "\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
 		break;
 	case FOTA_DOWNLOAD_EVT_ERASE_DONE:
-		rsp_send("\r\n#XFOTA: %d,%d\r\n", FOTA_STAGE_DOWNLOAD_ERASED, sm_fota_status);
+		urc_send_to(fota_pipe, "\r\n#XFOTA: %d,%d\r\n", FOTA_STAGE_DOWNLOAD_ERASED,
+			    sm_fota_status);
 		/* Back to init now that the erasure is complete so that potential pre-start
 		 * error codes are printed with the same stage than if there had been no erasure.
 		 */
@@ -315,15 +317,15 @@ static void fota_dl_handler(const struct fota_download_evt *evt)
 	case FOTA_DOWNLOAD_EVT_ERROR:
 		sm_fota_status = FOTA_STATUS_ERROR;
 		sm_fota_info = evt->cause;
-		rsp_send("\r\n#XFOTA: %d,%d,%d\r\n",
+		urc_send_to(fota_pipe, "\r\n#XFOTA: %d,%d,%d\r\n",
 			sm_fota_stage, sm_fota_status, sm_fota_info);
 		/* FOTA session terminated */
 		sm_fota_init_state();
 		break;
 	case FOTA_DOWNLOAD_EVT_CANCELLED:
 		sm_fota_status = FOTA_STATUS_CANCELLED;
 		sm_fota_info = 0;
-		rsp_send("\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
+		urc_send_to(fota_pipe, "\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
 		/* FOTA session terminated */
 		sm_fota_init_state();
 		break;
@@ -345,6 +347,7 @@ static int handle_at_fota(enum at_parser_cmd_type cmd_type, struct at_parser *pa
 
 	switch (cmd_type) {
 	case AT_PARSER_CMD_TYPE_SET:
+		fota_pipe = sm_at_host_get_current_pipe();
 		err = at_parser_num_get(parser, 1, &op);
 		if (err < 0) {
 			return err;
@@ -492,10 +495,12 @@ void sm_fota_post_process(void)
 	}
 	LOG_INF("FOTA result %d,%d,%d", sm_fota_stage, sm_fota_status, sm_fota_info);
 
+	struct modem_pipe *pipe = fota_pipe ? fota_pipe : sm_at_host_get_urc_pipe();
+
 	if (sm_fota_status == FOTA_STATUS_OK) {
-		rsp_send("\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
+		urc_send_to(pipe, "\r\n#XFOTA: %d,%d\r\n", sm_fota_stage, sm_fota_status);
 	} else {
-		rsp_send("\r\n#XFOTA: %d,%d,%d\r\n", sm_fota_stage, sm_fota_status,
+		urc_send_to(pipe, "\r\n#XFOTA: %d,%d,%d\r\n", sm_fota_stage, sm_fota_status,
 			sm_fota_info);
 	}
 

app/src/sm_at_gnss.c

@@ -81,6 +81,8 @@ static struct k_work gnss_status_notify_work;
 /* FIFO to pass the GNSS statuses to the notifier worker. */
 K_FIFO_DEFINE(gnss_status_fifo);
 
+static struct modem_pipe *gnss_pipe;
+
 /* Whether to use the nRF Cloud assistive services that were compiled in (A-GNSS/P-GPS).
  * If enabled, the connection to nRF Cloud is required during GNSS startup
  * and assistance data will be downloaded.
@@ -123,7 +125,7 @@ static void gnss_status_notifier(struct k_work *)
 {
 	while (!k_fifo_is_empty(&gnss_status_fifo)) {
 		gnss_status = (enum gnss_status)k_fifo_get(&gnss_status_fifo, K_NO_WAIT);
-		rsp_send("\r\n#XGNSS: 1,%d\r\n", gnss_status);
+		urc_send_to(gnss_pipe, "\r\n#XGNSS: 1,%d\r\n", gnss_status);
 	}
 }
 
@@ -517,11 +519,11 @@ static void gnss_fix_sender(struct k_work *)
 	}
 
 	/* GIS accuracy: http://wiki.gis.com/wiki/index.php/Decimal_degrees, use default .6lf */
-	rsp_send("\r\n#XGNSS: %lf,%lf,%f,%f,%f,%f,\"%04u-%02u-%02u %02u:%02u:%02u\"\r\n",
-		pvt.latitude, pvt.longitude, (double)pvt.altitude,
-		(double)pvt.accuracy, (double)pvt.speed, (double)pvt.heading,
-		pvt.datetime.year, pvt.datetime.month, pvt.datetime.day,
-		pvt.datetime.hour, pvt.datetime.minute, pvt.datetime.seconds);
+	urc_send_to(gnss_pipe,
+		    "\r\n#XGNSS: %lf,%lf,%f,%f,%f,%f,\"%04u-%02u-%02u %02u:%02u:%02u\"\r\n",
+		    pvt.latitude, pvt.longitude, (double)pvt.altitude, (double)pvt.accuracy,
+		    (double)pvt.speed, (double)pvt.heading, pvt.datetime.year, pvt.datetime.month,
+		    pvt.datetime.day, pvt.datetime.hour, pvt.datetime.minute, pvt.datetime.seconds);
 
 	for (int i = 0; i < NRF_MODEM_GNSS_MAX_SATELLITES; ++i) {
 		if (pvt.sv[i].sv) { /* SV number 0 indicates no satellite */
@@ -660,6 +662,8 @@ static int handle_at_gnss(enum at_parser_cmd_type cmd_type, struct at_parser *pa
 				return -EBUSY;
 			}
 
+			gnss_pipe = sm_at_host_get_current_pipe();
+
 			err = at_parser_num_get(
 				parser, CLOUD_ASSISTANCE_IDX, &gnss_cloud_assistance);
 			if (err || gnss_cloud_assistance > 1) {