66AK2H14: Led GPIO use in U-boot

L.Kiet

Part Number: 66AK2H14

Hi,

We have a custom board using 66AK2H14 processor.

I am currently trying to boot our new custom board. The first step for this is to run U-boot.

To know that my U-boot is working on custom board, I want to make some leds working on it, allowing me to see that u-boot is living.

For this, I tried first to add the gpio led support in my EVM u-boot, before using it in my custom board U-boot.

However, until now, it is not working, I miss something.

For now,, I add the gpio support and the led support to my config using menuconfig (device drivers->led support). I also tried to add the command line interface for gpio ( command line interface -> Device access commands -> gpio).

I tried to use the gpio function in ddr3_k2hk.c file, during init. Howver, I can't see any results on my LED.

I tried the following functions :

status = gpio_request(12, "led1");

gpio_direction_output(12, 1);

mdelay(2000);

gpio_direction_output(12, 0);

mdelay(2000);

led1 is the name I defined in the device tree source. 12 is the number of the gpio, knowing that I tested it in a DSP application with emulator and it is perfectly working, as using gpio 13, 14 and 15 for the 3 other leds.

Do you see any mistake I do or anything I am missing?

Thank you for your help.

Best Regards.

K.Luong

over 5 years ago

0 Yordan Kovachev over 5 years ago

TI__Guru**** 161600 points

Hi,

Before being able to control gpio (leds) in u-boot you need to make sure you've correctly initialized your board (Pinmux, clock, DDR). Also you should get some output on your debug console from u-boot, something like:

Best Regards,
Yordan

0 L.Kiet over 5 years ago in reply to Yordan Kovachev

Intellectual 510 points

Hi,

Thank you for this answer. However, I want to use leds from u-boot in my evaluation board EVMK2Hx and my EVM is booting of course.

The case of my custom board is independant to this problem. However, I already change my DDR3 settings by the one we used in the GEL file and allows us to access DDR by DSP emulation. I changed the clock by our clock. I don't think I have pinmux to initialize in my board based on this processor, as there is no pinmux in EVMK2Hx, am I right? Anyway, I got also output on UART.

Thank you for your answer.

Best Regards,

K.Luong

0 Yordan Kovachev over 5 years ago in reply to L.Kiet

TI__Guru**** 161600 points

I don't think I have pinmux to initialize in my board based on this processor, as there is no pinmux in EVMK2Hx, am I right?

Correct, 66AK2Hx devices don't need pinmuxing, as there are no muxes on the SoC pads.

Best Regards,
Yordan

0 L.Kiet over 5 years ago in reply to Yordan Kovachev

Intellectual 510 points

Hi,

Do you have any suggestions about my problem described in my first comment?

Best Regards,

K.Luong

0 Yordan Kovachev over 5 years ago in reply to L.Kiet

TI__Guru**** 161600 points

Hi,

If you're able to boot your board and you like to enable the gpio, you should enable it in the u-boot dts files located in arch/arm/boot/dts/k2hk-evm.dts.

Best Regards,
Yordan

0 L.Kiet over 5 years ago in reply to Yordan Kovachev

Intellectual 510 points

Hi,

I would like to use it in U-boot, not in linux. How to add it in dts. For me, it is already defined in arch/arm/dts/keystone.dtsi.

However, how to make it enable and where to do it exactly?

Best Regards,

K.Luong

0 Yordan Kovachev over 5 years ago in reply to L.Kiet

TI__Guru**** 161600 points

Just for debugging purpose, can you try writing to GPIO registers from u-boot console, using md? Are you able to modify the register values?

As for enabling the GPIO controller, this could be done simply by adding status="okay"; in the dts node in keystone.dtsi.

Best Regards,
Yordan

0 L.Kiet over 5 years ago in reply to Yordan Kovachev

Intellectual 510 points

I tried to write to gpio configuration register with mw u-boot command without success. I am not able to modify the register values. I can read it with md command.

I tried to put status="okay" in my gpio node. However, it doesn't change anything.

Best Regards,

K.Luong

0 Yordan Kovachev over 5 years ago in reply to L.Kiet

TI__Guru**** 161600 points

Can you share the changes you make in u-boot sources?

Best Regards,
Yordan

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66AK2H14: Led GPIO use in U-boot