boards: nrf52833dk|nrf21540dk: fix UART1 pinctrl instructions

nRF52840DK documentation was updated with details on how to change UART1
pins. nRF52833DK and nRF21540 boards has the same incorrect instructions
and were not fixed. Do it now.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

boards/arm/nrf21540dk_nrf52840/doc/index.rst

@@ -175,25 +175,25 @@ You can build and flash the examples to make sure Zephyr is running correctly on
 your board. The button and LED definitions can be found in
 :zephyr_file:`boards/arm/nrf21540dk_nrf52840/nrf21540dk_nrf52840.dts`.
 
-Using UART1
-***********
+Changing UART1 pins
+*******************
 
-The following approach can be used when an application needs to use
-more than one UART for connecting peripheral devices:
+The following approach can be used when an application needs to use another set
+of pins for UART1:
 
 1. Add devicetree overlay file to the main directory of your application:
 
    .. code-block:: devicetree
 
       &pinctrl {
-         uart1_default: uart1_default {
+         uart1_default_alt: uart1_default_alt {
             group1 {
                psels = <NRF_PSEL(UART_TX, 0, 14)>,
                        <NRF_PSEL(UART_RX, 0, 16)>;
             };
          };
          /* required if CONFIG_PM_DEVICE=y */
-         uart1_sleep: uart1_sleep {
+         uart1_sleep_alt: uart1_sleep_alt {
             group1 {
                psels = <NRF_PSEL(UART_TX, 0, 14)>,
                        <NRF_PSEL(UART_RX, 0, 16)>;
@@ -203,18 +203,16 @@ more than one UART for connecting peripheral devices:
       };
 
       &uart1 {
-        compatible = "nordic,nrf-uarte";
-        current-speed = <115200>;
-        status = "okay";
-        pinctrl-0 = <&uart1_default>;
-        pinctrl-1 = <&uart1_sleep>;
+        pinctrl-0 = <&uart1_default_alt>;
+        /* if sleep state is not used, use /delete-property/ pinctrl-1; and
+         * skip the "sleep" entry.
+         */
+        pinctrl-1 = <&uart1_sleep_alt>;
         pinctrl-names = "default", "sleep";
       };
 
    In the overlay file above, pin P0.16 is used for RX and P0.14 is used for TX
 
-2. Use the UART1 as ``DEVICE_DT_GET(DT_NODELABEL(uart1))``
-
 See :ref:`set-devicetree-overlays` for further details.
 
 Selecting the pins

boards/arm/nrf52833dk_nrf52833/doc/index.rst

@@ -157,25 +157,25 @@ You can build and flash the examples to make sure Zephyr is running correctly on
 your board. The button and LED definitions can be found in
 :zephyr_file:`boards/arm/nrf52833dk_nrf52833/nrf52833dk_nrf52833.dts`.
 
-Using UART1
-***********
+Changing UART1 pins
+*******************
 
-The following approach can be used when an application needs to use
-more than one UART for connecting peripheral devices:
+The following approach can be used when an application needs to use another set
+of pins for UART1:
 
 1. Add devicetree overlay file to the main directory of your application:
 
    .. code-block:: devicetree
 
       &pinctrl {
-         uart1_default: uart1_default {
+         uart1_default_alt: uart1_default_alt {
             group1 {
                psels = <NRF_PSEL(UART_TX, 0, 14)>,
                        <NRF_PSEL(UART_RX, 0, 16)>;
             };
          };
          /* required if CONFIG_PM_DEVICE=y */
-         uart1_sleep: uart1_sleep {
+         uart1_sleep_alt: uart1_sleep_alt {
             group1 {
                psels = <NRF_PSEL(UART_TX, 0, 14)>,
                        <NRF_PSEL(UART_RX, 0, 16)>;
@@ -185,18 +185,16 @@ more than one UART for connecting peripheral devices:
       };
 
       &uart1 {
-        compatible = "nordic,nrf-uarte";
-        current-speed = <115200>;
-        status = "okay";
-        pinctrl-0 = <&uart1_default>;
-        pinctrl-1 = <&uart1_sleep>;
+        pinctrl-0 = <&uart1_default_alt>;
+        /* if sleep state is not used, use /delete-property/ pinctrl-1; and
+         * skip the "sleep" entry.
+         */
+        pinctrl-1 = <&uart1_sleep_alt>;
         pinctrl-names = "default", "sleep";
       };
 
    In the overlay file above, pin P0.16 is used for RX and P0.14 is used for TX
 
-2. Use the UART1 as ``DEVICE_DT_GET(DT_NODELABEL(uart1))``
-
 See :ref:`set-devicetree-overlays` for further details.
 
 Selecting the pins