TS-7250-V3 TS-SER4

TS-SER4

Product Page
8-bit IO

The TS-SER4 supports 4 UARTs as RS-232, RS-485, or RS-422. Refer to the TS-SER4 manual for hardware documentation.

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-SER4 with the IRQ2, IRQ4 (selects IRQ6), and COM1 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 {
    ...
	#address-cells = <0x1>;
	#size-cells = <0x1>;

	/* COMA */
	ts16550@3f8 {
		compatible = "technologic,ts16550";

		reg = <0x3f8 8>;
		interrupt-parent = <&fpga_intc>;
		interrupts = <15 IRQ_TYPE_LEVEL_HIGH>;
	};

	/* COMB */
	ts16550@2f8 {
		compatible = "technologic,ts16550";

		reg = <0x2f8 8>;
		interrupt-parent = <&fpga_intc>;
		interrupts = <15 IRQ_TYPE_LEVEL_HIGH>;
	};

	/* COMC */
	ts16550@3e8 {
		compatible = "technologic,ts16550";

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

	/* COMD */
	ts16550@2e8 {
		compatible = "technologic,ts16550";

		reg = <0x2e8 8>;
		interrupt-parent = <&fpga_intc>;
		interrupts = <15 IRQ_TYPE_LEVEL_HIGH>;
	};
};

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

root@tsimx6:~# dmesg | grep ts16550
[    2.259413] ts16550 50004050.fpgaisa:ts16550@3f8: Adding 16550 UART ttyS0
[    2.268166] ts16550 50004050.fpgaisa:ts16550@2f8: Adding 16550 UART ttyS1
[    2.278539] ts16550 50004050.fpgaisa:ts16550@3e8: Adding 16550 UART ttyS2
[    2.287455] ts16550 50004050.fpgaisa:ts16550@2e8: Adding 16550 UART ttyS3

Now that these are loaded:

Device	Description
/dev/ttyS0	COMA
/dev/ttyS1	COMB
/dev/ttyS3	COMC
/dev/ttyS4	COMD