overlays: Add full-duplex rs485 support to uart2-5

Add full-duplex support to the rs485 modes of UARTs 2 to 5. From the
README:

    rs485_full_duplex   When RS485 mode is enabled, enables receiving of
                        data while sending data (default off)

See: https://forums.raspberrypi.com/viewtopic.php?t=394687
Signed-off-by: Phil Elwell <phil@raspberrypi.com>

Author: pelwell

arch/arm/boot/dts/overlays/README

@@ -5325,6 +5325,8 @@ Params: ctsrts                  Enable CTS/RTS on GPIOs 2-3 (default off)
                                 drive the OE pin of an RS485 transceiver (i.e.
                                 MAX3078E); also enables the UARTx ctsrts
                                 parameter, as RTS is required (default off).
+        rs485_full_duplex       When RS485 mode is enabled, enables receiving of
+                                data while sending data (default off)
         rs485_invert_rts        When RS485 mode is enabled, inverts the RTS
                                 line from active-high (default) to active-low.
         rs485_rts_on_delay      When RS485 mode is enabled, sets the delay (in
@@ -5349,6 +5351,8 @@ Params: ctsrts                  Enable CTS/RTS on GPIOs 6-7 (default off)
                                 drive the OE pin of an RS485 transceiver (i.e.
                                 MAX3078E); also enables the UARTx ctsrts
                                 parameter, as RTS is required (default off).
+        rs485_full_duplex       When RS485 mode is enabled, enables receiving of
+                                data while sending data (default off)
         rs485_invert_rts        When RS485 mode is enabled, inverts the RTS
                                 line from active-high (default) to active-low.
         rs485_rts_on_delay      When RS485 mode is enabled, sets the delay (in
@@ -5373,6 +5377,8 @@ Params: ctsrts                  Enable CTS/RTS on GPIOs 10-11 (default off)
                                 drive the OE pin of an RS485 transceiver (i.e.
                                 MAX3078E); also enables the UARTx ctsrts
                                 parameter, as RTS is required (default off).
+        rs485_full_duplex       When RS485 mode is enabled, enables receiving of
+                                data while sending data (default off)
         rs485_invert_rts        When RS485 mode is enabled, inverts the RTS
                                 line from active-high (default) to active-low.
         rs485_rts_on_delay      When RS485 mode is enabled, sets the delay (in
@@ -5397,6 +5403,8 @@ Params: ctsrts                  Enable CTS/RTS on GPIOs 14-15 (default off)
                                 drive the OE pin of an RS485 transceiver (i.e.
                                 MAX3078E); also enables the UARTx ctsrts
                                 parameter, as RTS is required (default off).
+        rs485_full_duplex       When RS485 mode is enabled, enables receiving of
+                                data while sending data (default off)
         rs485_invert_rts        When RS485 mode is enabled, inverts the RTS
                                 line from active-high (default) to active-low.
         rs485_rts_on_delay      When RS485 mode is enabled, sets the delay (in

arch/arm/boot/dts/overlays/uart2-overlay.dts

@@ -30,6 +30,7 @@
 	__overrides__ {
 		ctsrts = <0>,"=1";
 		rs485 = <0>,"=1=2";
+		rs485_full_duplex = <&rs485>,"rs485-rx-during-tx?";
 		rs485_invert_rts = <&rs485>,"rs485-rts-active-low?";
 		rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
 		rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";

arch/arm/boot/dts/overlays/uart3-overlay.dts

@@ -30,6 +30,7 @@
 	__overrides__ {
 		ctsrts = <0>,"=1";
 		rs485 = <0>,"=1=2";
+		rs485_full_duplex = <&rs485>,"rs485-rx-during-tx?";
 		rs485_invert_rts = <&rs485>,"rs485-rts-active-low?";
 		rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
 		rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";

arch/arm/boot/dts/overlays/uart4-overlay.dts

@@ -30,6 +30,7 @@
 	__overrides__ {
 		ctsrts = <0>,"=1";
 		rs485 = <0>,"=1=2";
+		rs485_full_duplex = <&rs485>,"rs485-rx-during-tx?";
 		rs485_invert_rts = <&rs485>,"rs485-rts-active-low?";
 		rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
 		rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";

arch/arm/boot/dts/overlays/uart5-overlay.dts

@@ -30,6 +30,7 @@
 	__overrides__ {
 		ctsrts = <0>,"=1";
 		rs485 = <0>,"=1=2";
+		rs485_full_duplex = <&rs485>,"rs485-rx-during-tx?";
 		rs485_invert_rts = <&rs485>,"rs485-rts-active-low?";
 		rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
 		rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";