How to use the SERIAL ports on Acqua

This article illustrates how to activate and use the serial ports available on Acqua A5

Pinout and device tree definitions port by port

Signal	Dir	Description	Pin
TXD0	O	Transmit data	J2.14 (PD18)
RXD0	I	Receive data	J2.11 (PD17)
RTS0	O	Request to send	J2.12 (PD16)
CTS0	I	Clear to send	J2.9 (PD15)

usart0: serial@f001c000 {
    status = "okay";
};

Signal	Dir	Description	Pin
TXD1	O	Transmit data	J2.46 (PB29)
RXD1	I	Receive data	J2.45 (PB28)

usart1: serial@f0020000 {
    status = "okay";
};

Signal	Dir	Description	Pin
TXD2	O	Transmit data	J3.13 (PE26)
RXD2	I	Receive data	J3.12 (PE25)
RTS2	O	Request to send	J3.11 (PE24)
CTS2	I	Clear to send	J3.10 (PE23)

usart2: serial@f8020000 {
    status = "okay";
};

Signal	Dir	Description	Pin
TXD3	O	Transmit data	J3.7 (PE19)
RXD3	I	Receive data	J3.8 (PE18)
RTS3	O	Request to send	J3.5 (PE17)
CTS3	I	Clear to send	J3.6 (PE16)

usart3: serial@f8024000 {
    status = "okay";
};

Signal	Dir	Description	Pin
UTXD0	O	Transmit data	J3.30 (PC30)
URXD0	I	Receive data	J3.31 (PC29)

uart0: serial@f0024000 {
    status = "okay";
};

Signal	Dir	Description	Pin
UTXD1	O	Transmit data	J3.41 (PA31)
URXD1	I	Receive data	J3.32 (PA30)

uart1: serial@f8028000 {
    status = "okay";
};

Signal	Dir	Description	Pin
DTXD	O	Debug port tx data	J3.4 (PB31)
DRXD	I	Debug port rx data	J3.3 (PB30)

Compiling Linux Kernel 4.19.x LTS for Acqua (This article includes the instructions to compile the device tree file)
Atmel usart binding
DMA bindings

Sergio Tanzilli
Systems designer, webmaster of www.acmesystems.it and founder of Acme Systems srl

Personal email: tanzilli@acmesystems.it
Web pages: https://www.acmesystems.it --- https://www.acmestudio.it
Github repositories: https://github.com/tanzilli --- https://github.com/acmesystems
Telegram group dedicated to the Acme Systems boards: https://t.me/acmesystemssrl