TS-7250-V3 TS-SER2

TS-SER2

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8-bit IO

The TS-SER2 provides two RS-232, RS-485 half duplex or full duplex (RS-422) ports and a parallel port. Refer to the TS-SER2 manual for hardware documentation. The parallel port is currently not supported on this platform.

This peripheral implements 16550A based UARTs which require a kernel driver. Under Linux this requires a device tree change. See the Kernel compile section for more details about getting set up the compile the kernel.

In general for 16550 UARTs we recommend these kernel config options:

CONFIG_HZ_PERIODIC=y
CONFIG_HZ_1000=y
CONFIG_SERIAL_8250_TS=y

The default kernel is ideal for low power, but has some tradeoffs with latency. A 16550 only has a 16 byte FIFO and needs to be serviced with relatively low latency, so a the above options make the latency far more deterministic. These changes are necessary to run at 115200 and not drop any data.

This below example will set up the serial devices for a TS-SER2 with JP 14 through JP18, COMB 6, and COMA 5 jumpers installed. Open the device tree at arch/arm/boot/dts/imx6ul-ts7250v3.dtsi. Add the highlighted section to the device tree and recompile.

pc104bus: fpgaisa@50 {
	compatible = "technologic,pc104-bus";
	reg = <0x50 0x4>;

	ranges = <0 0 0x1000>;
	reset-gpio = <&gpio3 7 0>;

	#address-cells = <0x1>;
	#size-cells = <0x1>;

	/* TS-SER2 COMA */
	ts16550@2e8 {
		compatible = "technologic,ts16550";

		reg = <0x2e8 8>;
		interrupt-parent = <&fpga_intc>;
		interrupts = <14>;
	};

	/* TS-SER2 COMB */
	ts16550@3e8 {
		compatible = "technologic,ts16550";

		reg = <0x3e8 8>;
		interrupt-parent = <&fpga_intc>;
		interrupts = <15>;
	};
};

On the next boot check the "dmesg" output to verify it loaded:

root@tsimx6:~# dmesg | grep ts16550
[    2.259413] ts16550 50004050.fpgaisa:ts16550@2e8: Adding 16550 UART ttyS0
[    2.268166] ts16550 50004050.fpgaisa:ts16550@3e8: Adding 16550 UART ttyS1

Now that these are loaded:

Device	Description
/dev/ttyS0	COMA
/dev/ttyS1	COMB

In this mode COMA/COMB are full duplex RS-485 (RS-422). See the TS-ISO485 manual for mroe details on the HD jumpers to use half duplex.