drivers: serial: nrfx_uarte: Deprecate non-legacy shim

Some time ago a new shim for nRF UARTE was added (uart_nrfx_uarte2.c)
which used nrfx_uarte.c driver underneath. It was supposed to support
nrf54x platforms. However, later on legacy driver (uart_nrfx_uarte.c)
was extended to support nrf54x platforms and it takes less code size,
has better performance and more features. Shim uart_nrfx_uarte2 will
no longer be supported. As new shim is the default and there is a
Kconfig to pick the legacy shim (CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y)
it cannot be deprecated in the normal way. Additional Kconfig option
is created (DEPRECATED_UART_NRFX_UARTE_LEGACY_SHIM) which is enabled
if CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=n and it selects DEPRECATED.
A warning was also added to the CMakeLists.txt.

Patch removes use CONFIG_UART_NRFX_UARTE_LEGACY_SHIM in tests.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

drivers/serial/CMakeLists.txt

@@ -93,6 +93,8 @@ if (CONFIG_UART_NRFX_UARTE)
   if (CONFIG_UART_NRFX_UARTE_LEGACY_SHIM)
     zephyr_library_sources(uart_nrfx_uarte.c)
   else()
+    message(DEPRECATION
+	    "Do not set CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=n as this option is deprecated.")
     zephyr_library_sources(uart_nrfx_uarte2.c)
   endif()
 endif()

drivers/serial/Kconfig.nrfx

@@ -32,6 +32,8 @@ config UART_NRFX_UARTE_LEGACY_SHIM
 	bool "Legacy UARTE shim"
 	depends on UART_NRFX_UARTE
 	default y
+	help
+	  Disabling this option is deprecated.
 
 config UART_NRFX_UARTE_ENHANCED_RX
 	bool "Enhanced RX handling"

soc/nordic/Kconfig

@@ -197,4 +197,9 @@ config NRF_PLATFORM_HALTIUM
 	  this option. This allows to easily enable common functionality on
 	  SoCs based on the Haltium platform.
 
+config DEPRECATED_UART_NRFX_UARTE_LEGACY_SHIM
+	bool
+	default y if !UART_NRFX_UARTE_LEGACY_SHIM
+	select DEPRECATED
+
 endif # SOC_FAMILY_NORDIC_NRF

tests/drivers/uart/uart_async_api/testcase.yaml

@@ -25,20 +25,6 @@ tests:
     platform_allow: nucleo_h743zi
     integration_platforms:
       - nucleo_h743zi
-  drivers.uart.async_api.nrf_uarte_new:
-    platform_allow:
-      - nrf52840dk/nrf52840
-      - nrf52_bsim
-      - nrf5340bsim/nrf5340/cpuapp
-      - nrf54l20pdk/nrf54l20/cpuapp
-      - nrf54l15bsim/nrf54l15/cpuapp
-    filter: CONFIG_SERIAL_SUPPORT_ASYNC
-    harness: ztest
-    harness_config:
-      fixture: gpio_loopback
-    depends_on: gpio
-    extra_configs:
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=n
   drivers.uart.async_api.nrf_uart:
     filter: CONFIG_SERIAL_SUPPORT_ASYNC
     harness: ztest

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

@@ -1 +0,0 @@
-CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=n

tests/drivers/uart/uart_pm/testcase.yaml

@@ -23,14 +23,12 @@ tests:
       - CONFIG_UART_INTERRUPT_DRIVEN=n
       - CONFIG_UART_ASYNC_API=n
       - CONFIG_UART_0_ENHANCED_POLL_OUT=n
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
 
   drivers.uart.pm.no_rxpin:
     extra_configs:
       - CONFIG_UART_INTERRUPT_DRIVEN=n
       - CONFIG_UART_ASYNC_API=n
       - CONFIG_UART_0_ENHANCED_POLL_OUT=n
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
     extra_args: DTC_OVERLAY_FILE="boards/nrf52840dk_nrf52840.overlay;nrf_rx_disable.overlay"
     platform_exclude:
       - nrf54l09pdk/nrf54l09/cpuapp
@@ -38,13 +36,14 @@ tests:
       - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54l15bsim/nrf54l15/cpuapp
       - nrf54h20dk/nrf54h20/cpuapp
+      - nrf52_bsim
+      - nrf5340bsim/nrf5340/cpuapp
 
   drivers.uart.pm.enhanced_poll:
     extra_configs:
       - CONFIG_UART_INTERRUPT_DRIVEN=n
       - CONFIG_UART_ASYNC_API=n
       - CONFIG_UART_0_ENHANCED_POLL_OUT=y
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
     platform_exclude:
       - nrf54l09pdk/nrf54l09/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
@@ -57,7 +56,6 @@ tests:
       - CONFIG_UART_0_INTERRUPT_DRIVEN=y
       - CONFIG_UART_ASYNC_API=n
       - CONFIG_UART_0_ENHANCED_POLL_OUT=n
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
 
   drivers.uart.pm.int_driven.enhanced_poll:
     extra_configs:
@@ -65,7 +63,6 @@ tests:
       - CONFIG_UART_0_INTERRUPT_DRIVEN=y
       - CONFIG_UART_ASYNC_API=n
       - CONFIG_UART_0_ENHANCED_POLL_OUT=y
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
     platform_exclude:
       - nrf54l09pdk/nrf54l09/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
@@ -78,7 +75,6 @@ tests:
       - CONFIG_UART_ASYNC_API=y
       - CONFIG_UART_0_ASYNC=y
       - CONFIG_UART_0_ENHANCED_POLL_OUT=n
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
 
   drivers.uart.pm.async.enhanced_poll:
     extra_configs:
@@ -86,7 +82,6 @@ tests:
       - CONFIG_UART_ASYNC_API=y
       - CONFIG_UART_0_ASYNC=y
       - CONFIG_UART_0_ENHANCED_POLL_OUT=y
-      - CONFIG_UART_NRFX_UARTE_LEGACY_SHIM=y
     platform_exclude:
       - nrf54l09pdk/nrf54l09/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp