drivers: serial: nrfx_uarte: Deprecate CONFIG_UART_x_NRF_HW_ASYNC

Deprecate mode which is using TIMER+(D)PPI for reliable byte counting.
Recently a new approach is added (CONFIG_UART_NRFX_UARTE_ENHANCED_RX)
which supports reliable byte counting without additional HW resource.
This mode is planned to be the only supported RX path mode.

Enhanced RX has slightly different behavior. There are no partial RX
packets (events with non-zero offset). There is UART_RX_BUF_RELEASED
after each UART_RX_RDY event.

Signed-off-by: Krzysztof Chruściński <[email protected]>

Author: nordic-krch

drivers/serial/Kconfig.nrfx

@@ -37,7 +37,7 @@ config UART_NRFX_UARTE_ENHANCED_RX
 	bool "Enhanced RX handling"
 	depends on UART_ASYNC_API
 	depends on UART_NRFX_UARTE_LEGACY_SHIM
-	default y if !(UART_0_NRF_HW_ASYNC || UART_1_NRF_HW_ASYNC || UART_2_NRF_HW_ASYNC)
+	default y
 	help
 	  Enable RX handling mode which is switching buffers on timeout. This is an
 	  enhancement compared to other two modes (default and hardware assisted).

drivers/serial/Kconfig.nrfx_uart_instance

@@ -49,18 +49,23 @@ config UART_$(nrfx_uart_num)_NRF_TX_BUFFER_SIZE
 	  particular SoC.
 
 config UART_$(nrfx_uart_num)_NRF_HW_ASYNC
-	bool "Use hardware RX byte counting"
+	bool "[DEPRECATED] Use hardware RX byte counting"
 	depends on HAS_HW_NRF_UARTE$(nrfx_uart_num)
 	depends on UART_ASYNC_API
 	depends on UART_NRFX_UARTE_LEGACY_SHIM
+	depends on !UART_NRFX_UARTE_ENHANCED_RX
 	depends on HAS_HW_NRF_PPI || HAS_HW_NRF_DPPIC
 	select NRFX_GPPI
+	select DEPRECATED
 	help
 	  If default driver uses interrupts to count incoming bytes, it is possible
 	  that with higher speeds and/or high cpu load some data can be lost.
 	  It is recommended to use hardware byte counting in such scenarios.
 	  Hardware RX byte counting requires timer instance and one PPI channel.
 
+	  This options is deprecated. Use UART_NRFX_UARTE_ENHANCED_RX which supports
+	  reliable byte counting without additional HW resources (TIMER and (D)PPI).
+
 config UART_$(nrfx_uart_num)_NRF_ASYNC_LOW_POWER
 	bool "Low power mode"
 	depends on HAS_HW_NRF_UARTE$(nrfx_uart_num)

samples/net/cellular_modem/boards/nrf9160dk_nrf52840.conf

@@ -1,9 +1,6 @@
 CONFIG_UART_ASYNC_API=y
 CONFIG_UART_1_ASYNC=y
 CONFIG_UART_1_INTERRUPT_DRIVEN=n
-# Enable HW RX byte counting. This especially matters at higher baud rates.
-CONFIG_UART_1_NRF_HW_ASYNC=y
-CONFIG_UART_1_NRF_HW_ASYNC_TIMER=1
 
 # Align with the Serial LTE Modem (SLM) application.
 CONFIG_MODEM_CELLULAR_CMUX_MAX_FRAME_SIZE=1500

samples/net/cellular_modem/boards/nrf9160dk_nrf9160_ns.conf

@@ -1,9 +1,6 @@
 CONFIG_UART_ASYNC_API=y
 CONFIG_UART_1_ASYNC=y
 CONFIG_UART_1_INTERRUPT_DRIVEN=n
-# Enable HW RX byte counting. This especially matters at higher baud rates.
-CONFIG_UART_1_NRF_HW_ASYNC=y
-CONFIG_UART_1_NRF_HW_ASYNC_TIMER=1
 
 # Align with the Serial LTE Modem (SLM) application.
 CONFIG_MODEM_CELLULAR_CMUX_MAX_FRAME_SIZE=1500

tests/drivers/uart/uart_async_api/boards/nrf5340bsim_nrf5340_cpuapp.conf

@@ -1,3 +1 @@
 CONFIG_ARM_MPU=n
-CONFIG_UART_1_NRF_HW_ASYNC=y
-CONFIG_UART_1_NRF_HW_ASYNC_TIMER=2

tests/drivers/uart/uart_async_api/boards/nrf5340dk_nrf5340_cpuapp.conf

@@ -105,9 +105,6 @@ tests:
       - CONFIG_UART_0_INTERRUPT_DRIVEN=n
       - CONFIG_UART_0_ASYNC=y
       - CONFIG_UART_0_ENHANCED_POLL_OUT=n
-      - CONFIG_UART_0_NRF_HW_ASYNC=y
-      - CONFIG_UART_0_NRF_HW_ASYNC_TIMER=2
-      - CONFIG_NRFX_TIMER2=y
       - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
     platform_exclude:
       - nrf54l15dk/nrf54l15/cpuapp

tests/drivers/uart/uart_async_api/boards/nrf9160dk_nrf9160.conf

@@ -69,9 +69,6 @@ tests:
       - CONFIG_UART_INTERRUPT_DRIVEN=n
       - CONFIG_UART_ASYNC_API=y
       - CONFIG_UART_0_ASYNC=y
-      - CONFIG_UART_0_NRF_HW_ASYNC=y
-      - CONFIG_UART_0_NRF_HW_ASYNC_TIMER=2
-      - CONFIG_NRFX_TIMER2=y
       - CONFIG_UART_0_ENHANCED_POLL_OUT=n
       - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
 
@@ -80,9 +77,6 @@ tests:
       - CONFIG_UART_INTERRUPT_DRIVEN=n
       - CONFIG_UART_ASYNC_API=y
       - CONFIG_UART_0_ASYNC=y
-      - CONFIG_UART_0_NRF_HW_ASYNC=y
-      - CONFIG_UART_0_NRF_HW_ASYNC_TIMER=2
-      - CONFIG_NRFX_TIMER2=y
       - CONFIG_UART_0_ENHANCED_POLL_OUT=y
       - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
     platform_exclude: