AM5718: RS485 for UART2

xuelin mo

Part Number: AM5718

software:ti-processor-sdk-linux-rt-am57xx-evm-06.03.00.106

In my own board, we use RS485 for UART2.I modify some files according to https://e2e.ti.com/support/processors-group/processors/f/processors-forum/801483/am5728-u-boot-uart-setting.

1./board/ti/am57xx/mux_data.h

const struct pad_conf_entry early_padconf[] = {
{I2C1_SDA, (PIN_INPUT_PULLUP | M0)}, /* I2C1_SDA */
{I2C1_SCL, (PIN_INPUT_PULLUP | M0)}, /* I2C1_SCL */
{UART2_RXD, (M4 | PIN_INPUT)}, /* uart2_rxd.uart2_rxd */
{UART2_TXD, (M4 | PIN_OUTPUT)}, /* uart2_txd.uart2_txd */
};

2./arch/arm/dts/am57xx-beagle-x15-common.dtsi

chosen {
stdout-path = &uart2;
};

&uart2 {
status = "okay";
};

3./arch/arm/dts/omap5-u-boot.dtsi

&uart2 {
u-boot,dm-spl;
reg-shift = <2>;
};

4./arch/arm/dts/am57xx-idk-common.dtsi

chosen {
stdout-path = &uart2;
};

&uart2 {
status = "okay";
};

5.#define CONSOLEDEV "ttyS1"

I use ns16550 driver, and add CONS_INDEX = 2 in /board/ti/Kconfig

When I start my board, I can't see any output in my Serial terminal. I don't know why and I want to know how to modify it correctly?

over 4 years ago

0 Keerthy J over 4 years ago

TI__Guru**** 166750 points

Hi,

Which boot mode are you using? Do you have CCS setup? If yes can you check where it is hanging in the SPL code?

Best Regards,
Keerthy

0 xuelin mo over 4 years ago in reply to Keerthy J

Intellectual 335 points

I boot from SD card.I can't run ccs on linux

0 Keerthy J over 4 years ago in reply to xuelin mo

TI__Guru**** 166750 points

Hi,

See Section 4.4 of https://www.ti.com/lit/pdf/spruij9

And the AM571x IDK is very similar to the AM572x IDK so the steps are similar to http://software-dl.ti.com/processor-sdk-linux/esd/docs/06_03_00_106/linux/How_to_Guides/Hardware_Setup_with_CCS/TMDXIDK5728_Hardware_Setup.html

Best Regards,
Keerthy

0 xuelin mo over 4 years ago in reply to Keerthy J

Intellectual 335 points

My hardware is fine and I don't think it has anything to do with the problem I'm trying to solve

0 Keerthy J over 4 years ago in reply to xuelin mo

TI__Guru**** 166750 points

Xuelin,

I am not suspecting the hardware. The above links were provided for CCS setup. That will help us debug where the SPL is hanging.

Best Regards,
Keerthy

0 xuelin mo over 4 years ago in reply to Keerthy J

Intellectual 335 points

Oh, I see. But the SPL not hanging on my board,it runs normaly,just no uart output

0 Keerthy J over 4 years ago in reply to xuelin mo

TI__Guru**** 166750 points

Xuelin,

How did you verify that UART is the only issue? Can you let me know how you are able to verify that SPL is running fine
without getting any prints on the terminal?

- Keerthy

0 xuelin mo over 4 years ago in reply to Keerthy J

Intellectual 335 points

I verified by lighting the led in assembly language

0 Keerthy J over 4 years ago in reply to xuelin mo

TI__Guru**** 166750 points

Hi,

Since we do not know where the SPL is hanging. I recommend you to please use the CCS to check exactly where it is
crashing or hanging.

Keerthy J said:
See Section 4.4 of https://www.ti.com/lit/pdf/spruij9

And the AM571x IDK is very similar to the AM572x IDK so the steps are similar to http://software-dl.ti.com/processor-sdk-linux/esd/docs/06_03_00_106/linux/How_to_Guides/Hardware_Setup_with_CCS/TMDXIDK5728_Hardware_Setup.html

The above has the detailed procedure.

Best Regards,
Keerthy

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AM5718: RS485 for UART2