drivers: serial: Initial support for SCI UART

First commit to support serial driver running on r_sci_uart for Renesas
RA devices.

Signed-off-by: The Nguyen <the.nguyen.yf@renesas.com>
Signed-off-by: Duy Phuong Hoang. Nguyen <duy.nguyen.xa@renesas.com>

drivers/serial/CMakeLists.txt

@@ -77,6 +77,7 @@ zephyr_library_sources_ifdef(CONFIG_UART_ENE_KB1200 uart_ene_kb1200.c)
 zephyr_library_sources_ifdef(CONFIG_UART_RZT2M uart_rzt2m.c)
 zephyr_library_sources_ifdef(CONFIG_UART_RA8_SCI_B uart_renesas_ra8_sci_b.c)
 zephyr_library_sources_ifdef(CONFIG_USERSPACE   uart_handlers.c)
+zephyr_library_sources_ifdef(CONFIG_UART_SCI_RA uart_renesas_ra_sci.c)
 
 if(CONFIG_UART_NATIVE_POSIX)
   zephyr_library_compile_definitions(NO_POSIX_CHEATS)

drivers/serial/Kconfig.renesas_ra

@@ -1,4 +1,5 @@
 # Copyright (c) 2023 TOKITA Hiroshi <tokita.hiroshi@fujitsu.com>
+# Copyright (c) 2024 Renesas Electronics Corporation
 # SPDX-License-Identifier: Apache-2.0
 
 config UART_RENESAS_RA
@@ -9,3 +10,25 @@ config UART_RENESAS_RA
 	select SERIAL_SUPPORT_INTERRUPT
 	help
 	  Enable Renesas RA series UART driver.
+
+config UART_SCI_RA
+	bool "Renesas RA SCI UART"
+	default y
+	depends on DT_HAS_RENESAS_RA_SCI_UART_ENABLED
+	select SERIAL_HAS_DRIVER
+	select SERIAL_SUPPORT_INTERRUPT
+	select SERIAL_SUPPORT_ASYNC
+	select USE_RA_FSP_SCI_UART
+	select USE_RA_FSP_DTC if UART_ASYNC_API
+	help
+	  Enable Renesas RA SCI UART Driver.
+
+if UART_SCI_RA
+
+config UART_RA_SCI_UART_FIFO_ENABLE
+	bool "RA SCI UART FIFO usage enable"
+	default y
+	help
+	  Enable RA SCI FIFO
+
+endif

drivers/serial/uart_renesas_ra8_sci_b.c

@@ -1038,14 +1038,10 @@ static void uart_ra_sci_b_eri_isr(const struct device *dev)
 
 #define UART_RA_SCI_B_DTC_INIT(index)                                                              \
 	do {                                                                                       \
-		if (DT_INST_PROP_OR(index, rx_dtc, false)) {                                       \
-			uart_ra_sci_b_data_##index.fsp_config.p_transfer_rx =                      \
-				&uart_ra_sci_b_data_##index.rx_transfer;                           \
-		}                                                                                  \
-		if (DT_INST_PROP_OR(index, tx_dtc, false)) {                                       \
-			uart_ra_sci_b_data_##index.fsp_config.p_transfer_tx =                      \
-				&uart_ra_sci_b_data_##index.tx_transfer;                           \
-		}                                                                                  \
+		uart_ra_sci_b_data_##index.fsp_config.p_transfer_rx =                              \
+			&uart_ra_sci_b_data_##index.rx_transfer;                                   \
+		uart_ra_sci_b_data_##index.fsp_config.p_transfer_tx =                              \
+			&uart_ra_sci_b_data_##index.tx_transfer;                                   \
 	} while (0)
 
 #define UART_RA_SCI_B_ASYNC_INIT(index)                                                            \

dts/bindings/serial/renesas,ra-sci-uart.yaml

@@ -0,0 +1,13 @@
+# Copyright (c) 2024 Renesas Electronics Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+description: Renesas RA SCI UART controller
+
+compatible: "renesas,ra-sci-uart"
+
+include: [uart-controller.yaml, pinctrl-device.yaml]
+
+properties:
+  channel:
+    type: int
+    required: true

dts/bindings/serial/renesas,ra8-uart-sci-b.yaml

@@ -11,11 +11,3 @@ properties:
   channel:
     type: int
     required: true
-
-  tx-dtc:
-    type: boolean
-    description: Enable dtc support for transmit
-
-  rx-dtc:
-    type: boolean
-    description: Enable dtc support for receive

modules/Kconfig.renesas_fsp

@@ -22,3 +22,8 @@ config USE_RA_FSP_I2C_IIC
 	bool
 	help
 	  Enable Renesas RA I2C IIC Master driver
+
+config USE_RA_FSP_SCI_UART
+	bool
+	help
+	  Enable RA FSP SCI UART driver