applications: serial_lte_modem: Use downstream UART backend

Use downstream UART backend, which is optimized for use with
SLM.

Signed-off-by: Markus Lassila <[email protected]>

Author: MarkusLassila

applications/serial_lte_modem/overlay-cmux.conf

@@ -10,8 +10,12 @@ CONFIG_SLM_SKIP_READY_MSG=y
 # Zephyr modem subsystem
 CONFIG_MODEM_MODULES=y
 CONFIG_MODEM_CMUX=y
-CONFIG_MODEM_BACKEND_UART=y
-CONFIG_MODEM_BACKEND_UART_ASYNC_TRANSMIT_TIMEOUT_MS=1000
+
+# Enable SLM UART backend
+CONFIG_MODEM_BACKEND_UART=n
+CONFIG_MODEM_BACKEND_UART_ASYNC=n
+CONFIG_MODEM_BACKEND_UART_SLM=y
+CONFIG_MODEM_BACKEND_UART_SLM_TRANSMIT_TIMEOUT_MS=1000
 
 # debug options
 #CONFIG_MODEM_CMUX_LOG_LEVEL_DBG=y

applications/serial_lte_modem/overlay-ppp-cmux-linux.conf

@@ -9,16 +9,21 @@ CONFIG_SLM_CMUX=y
 CONFIG_SLM_PPP=y
 CONFIG_SLM_CR_TERMINATION=y
 
-# Assume at least baudrate 115200 for UART
-# so CMUX frame can be received in 12 ms (134*10/115200)
-CONFIG_MODEM_BACKEND_UART_ASYNC_RECEIVE_IDLE_TIMEOUT_MS=12
 CONFIG_MODEM_CMUX_MTU=127
 CONFIG_MODEM_CMUX_WORK_BUFFER_SIZE=536
 CONFIG_SLM_CMUX_UART_BUFFER_SIZE=6000
+
+# Enable SLM UART backend
+CONFIG_MODEM_BACKEND_UART=n
+CONFIG_MODEM_BACKEND_UART_ASYNC=n
+CONFIG_MODEM_BACKEND_UART_SLM=y
+
 # For sending full 6000 bytes at 115200 baudrate
 # 6000 * 10 / 115200 = 521 ms
-CONFIG_MODEM_BACKEND_UART_ASYNC_TRANSMIT_TIMEOUT_MS=521
-CONFIG_MODEM_BACKEND_UART_ASYNC_HWFC=y
+CONFIG_MODEM_BACKEND_UART_SLM_TRANSMIT_TIMEOUT_MS=521
+# Assume at least baudrate 115200 for UART
+# so CMUX frame can be received in 12 ms (134*10/115200)
+CONFIG_MODEM_BACKEND_UART_SLM_RECEIVE_IDLE_TIMEOUT_MS=12
 
 # These buffers are unused after AT#CMUX is enabled
 # so use minimal buffer size
@@ -43,7 +48,6 @@ CONFIG_NET_L2_PPP=y
 CONFIG_MODEM_MODULES=y
 CONFIG_MODEM_CMUX=y
 CONFIG_MODEM_PPP=y
-CONFIG_MODEM_BACKEND_UART=y
 
 # L2 protocol
 CONFIG_NET_L2_PPP_MGMT=y

applications/serial_lte_modem/overlay-ppp.conf

@@ -23,9 +23,12 @@ CONFIG_NET_NATIVE=y
 CONFIG_NET_L2_PPP=y
 CONFIG_MODEM_MODULES=y
 CONFIG_MODEM_PPP=y
-CONFIG_MODEM_BACKEND_UART=y
-CONFIG_MODEM_BACKEND_UART_ASYNC_TRANSMIT_TIMEOUT_MS=1000
-CONFIG_MODEM_BACKEND_UART_ASYNC_HWFC=y
+
+# Enable SLM UART backend
+CONFIG_MODEM_BACKEND_UART=n
+CONFIG_MODEM_BACKEND_UART_ASYNC=n
+CONFIG_MODEM_BACKEND_UART_SLM=y
+CONFIG_MODEM_BACKEND_UART_SLM_TRANSMIT_TIMEOUT_MS=1000
 
 # L2 protocol
 CONFIG_NET_L2_PPP_MGMT=y

applications/serial_lte_modem/src/slm_cmux.c

@@ -10,7 +10,7 @@
 #endif
 #include "slm_util.h"
 #include <zephyr/logging/log.h>
-#include <zephyr/modem/backend/uart.h>
+#include <zephyr/modem/backend/uart_slm.h>
 #include <zephyr/modem/cmux.h>
 #include <zephyr/modem/pipe.h>
 #include <assert.h>
@@ -35,7 +35,7 @@ static struct {
 	/* UART backend */
 	struct modem_pipe *uart_pipe;
 	bool uart_pipe_open;
-	struct modem_backend_uart uart_backend;
+	struct modem_backend_uart_slm uart_backend;
 	uint8_t uart_backend_receive_buf[CONFIG_SLM_CMUX_UART_BUFFER_SIZE]
 		__aligned(sizeof(void *));
 	uint8_t uart_backend_transmit_buf[CONFIG_SLM_CMUX_UART_BUFFER_SIZE];
@@ -348,15 +348,16 @@ static int cmux_start(void)
 	}
 
 	{
-		const struct modem_backend_uart_config uart_backend_config = {
+		const struct modem_backend_uart_slm_config uart_backend_config = {
 			.uart = DEVICE_DT_GET(DT_CHOSEN(ncs_slm_uart)),
 			.receive_buf = cmux.uart_backend_receive_buf,
 			.receive_buf_size = sizeof(cmux.uart_backend_receive_buf),
 			.transmit_buf = cmux.uart_backend_transmit_buf,
 			.transmit_buf_size = sizeof(cmux.uart_backend_transmit_buf),
 		};
 
-		cmux.uart_pipe = modem_backend_uart_init(&cmux.uart_backend, &uart_backend_config);
+		cmux.uart_pipe =
+			modem_backend_uart_slm_init(&cmux.uart_backend, &uart_backend_config);
 		if (!cmux.uart_pipe) {
 			return -ENODEV;
 		}

applications/serial_lte_modem/src/slm_ppp.c

@@ -14,7 +14,7 @@
 #include <modem/lte_lc.h>
 #include <modem/pdn.h>
 #include <zephyr/modem/ppp.h>
-#include <zephyr/modem/backend/uart.h>
+#include <zephyr/modem/backend/uart_slm.h>
 #include <zephyr/net/ethernet.h>
 #include <zephyr/net/net_if.h>
 #include <zephyr/net/ppp.h>
@@ -594,20 +594,20 @@ int slm_ppp_init(void)
 	}
 
 	{
-		static struct modem_backend_uart ppp_uart_backend;
+		static struct modem_backend_uart_slm ppp_uart_backend;
 		static uint8_t ppp_uart_backend_receive_buf[sizeof(ppp_data_buf)]
 			__aligned(sizeof(void *));
 		static uint8_t ppp_uart_backend_transmit_buf[sizeof(ppp_data_buf)];
 
-		const struct modem_backend_uart_config uart_backend_config = {
+		const struct modem_backend_uart_slm_config uart_backend_config = {
 			.uart = ppp_uart_dev,
 			.receive_buf = ppp_uart_backend_receive_buf,
 			.receive_buf_size = sizeof(ppp_uart_backend_receive_buf),
 			.transmit_buf = ppp_uart_backend_transmit_buf,
 			.transmit_buf_size = sizeof(ppp_uart_backend_transmit_buf),
 		};
 
-		ppp_pipe = modem_backend_uart_init(&ppp_uart_backend, &uart_backend_config);
+		ppp_pipe = modem_backend_uart_slm_init(&ppp_uart_backend, &uart_backend_config);
 		if (!ppp_pipe) {
 			return -ENOSYS;
 		}

west.yml

@@ -65,7 +65,7 @@ manifest:
     # https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/guides/modules.html
     - name: zephyr
       repo-path: sdk-zephyr
-      revision: 1e9016c290bc7e2e14445b77520fbab979f93e63
+      revision: pull/3021/head
       import:
         # In addition to the zephyr repository itself, NCS also
         # imports the contents of zephyr/west.yml at the above