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TheMightyMadmanTheMightyMadman
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Add RS485 mode support for UART2, UART3, UART4, and UART5.
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‎arch/arm/boot/dts/overlays/README‎

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@@ -5181,6 +5181,19 @@ Name: uart2
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Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
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Load: dtoverlay=uart2,<param>
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Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
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rs485 Enable RS485 mode for using the RTS line to
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drive the OE pin of an RS485 transceiver (i.e.
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MAX3078E); also enables the UARTx ctsrts
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parameter, as RTS is required (default off).
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rs485_invert_rts When RS485 mode is enabled, inverts the RTS
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line from active-high (default) to active-low
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(default off).
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rs485_rts_on_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission starting
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and the RTS line being asserted (default 0).
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rs485_rts_off_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission ending
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and the RTS line being deasserted (default 0).
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Name: uart2-pi5
@@ -5193,6 +5206,19 @@ Name: uart3
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Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
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Load: dtoverlay=uart3,<param>
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Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
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rs485 Enable RS485 mode for using the RTS line to
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drive the OE pin of an RS485 transceiver (i.e.
5211+
MAX3078E); also enables the UARTx ctsrts
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parameter, as RTS is required (default off).
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rs485_invert_rts When RS485 mode is enabled, inverts the RTS
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line from active-high (default) to active-low
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(default off).
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rs485_rts_on_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission starting
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and the RTS line being asserted (default 0).
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rs485_rts_off_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission ending
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and the RTS line being deasserted (default 0).
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51975223

51985224
Name: uart3-pi5
@@ -5205,6 +5231,19 @@ Name: uart4
52055231
Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
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Load: dtoverlay=uart4,<param>
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Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
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rs485 Enable RS485 mode for using the RTS line to
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drive the OE pin of an RS485 transceiver (i.e.
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MAX3078E); also enables the UARTx ctsrts
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parameter, as RTS is required (default off).
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rs485_invert_rts When RS485 mode is enabled, inverts the RTS
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line from active-high (default) to active-low
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(default off).
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rs485_rts_on_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission starting
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and the RTS line being asserted (default 0).
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rs485_rts_off_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission ending
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and the RTS line being deasserted (default 0).
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52095248

52105249
Name: uart4-pi5
@@ -5217,6 +5256,19 @@ Name: uart5
52175256
Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
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Load: dtoverlay=uart5,<param>
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Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
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rs485 Enable RS485 mode for using the RTS line to
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drive the OE pin of an RS485 transceiver (i.e.
5261+
MAX3078E); also enables the UARTx ctsrts
5262+
parameter, as RTS is required (default off).
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rs485_invert_rts When RS485 mode is enabled, inverts the RTS
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line from active-high (default) to active-low
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(default off).
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rs485_rts_on_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission starting
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and the RTS line being asserted (default 0).
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rs485_rts_off_delay When RS485 mode is enabled, sets the delay (in
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milliseconds) between data transmission ending
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and the RTS line being deasserted (default 0).
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52215273

52225274
Name: udrc

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

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@@ -19,7 +19,19 @@
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};
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};
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rs485: fragment@2 {
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target = <&uart2>;
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__dormant__ {
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linux,rs485-enabled-at-boot-time;
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rs485-rts-delay = <0 0>;
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};
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};
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__overrides__ {
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ctsrts = <0>,"=1";
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rs485 = <0>,"=1=2";
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rs485_invert_rts = <&rs485>,"rs485-rts-active-low";
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rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
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rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";
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};
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};

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

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@@ -19,7 +19,19 @@
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};
2020
};
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rs485: fragment@2 {
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target = <&uart3>;
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__dormant__ {
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linux,rs485-enabled-at-boot-time;
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rs485-rts-delay = <0 0>;
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};
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};
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__overrides__ {
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ctsrts = <0>,"=1";
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rs485 = <0>,"=1=2";
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rs485_invert_rts = <&rs485>,"rs485-rts-active-low";
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rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
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rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";
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};
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};

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

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@@ -19,7 +19,19 @@
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};
2020
};
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rs485: fragment@2 {
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target = <&uart4>;
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__dormant__ {
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linux,rs485-enabled-at-boot-time;
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rs485-rts-delay = <0 0>;
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};
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};
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__overrides__ {
2331
ctsrts = <0>,"=1";
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rs485 = <0>,"=1=2";
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rs485_invert_rts = <&rs485>,"rs485-rts-active-low";
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rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
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rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";
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};
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};

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

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@@ -19,7 +19,19 @@
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};
2020
};
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rs485: fragment@2 {
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target = <&uart5>;
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__dormant__ {
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linux,rs485-enabled-at-boot-time;
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rs485-rts-delay = <0 0>;
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};
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};
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__overrides__ {
2331
ctsrts = <0>,"=1";
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rs485 = <0>,"=1=2";
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rs485_invert_rts = <&rs485>,"rs485-rts-active-low";
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rs485_rts_on_delay = <&rs485>, "rs485-rts-delay:0";
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rs485_rts_off_delay = <&rs485>, "rs485-rts-delay:4";
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};
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};

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