AM625: Test GPIO leds

Rafael Silva

Part Number: AM625

Tool/software:

Hello,

We are trying to test set of GPIOs in a am62x Low Power SKEVM PROC124E2 board.

We are trying to validate the gpio set by trying to turn on/off a led.

We checked on the datasheet (https://www.ti.com/lit/ug/spruj51/spruj51.pdf?ts=1725896505812&ref_url=https%253A%252F%252Fwww.ti.com%252Fdocument-viewer%252Flit%252Fhtml%252FSPRUJ51)
and the only led that we found to test with gpio is the User test Led 1 which is the gpio1_49, which according to the "table 3-23. User Test LEDs" is the led LD3. We saw that this led is normally always blinking and we couldn't turn off on, don't know if it is supposed or not.

We would like to know what led for this revision can we use to test gpio to set on/off, to check it turning off and on, to validate this functionality visually.

We tested with a gpio that we saw available, GPIO0_8 WL_LT_EN, and seems to work with this one.

Also this datasheet is the most recent one for our HW revision?

Best regards,

Rafael Silva.

over 1 year ago

0 Tushar Thakur over 1 year ago

TI__Guru 57618 points

Hi Rafael,

Thanks for your query.

Rafael Silva said:
We saw that this led is normally always blinking and we couldn't turn off on, don't know if it is supposed or not.

Can you please tell how you are initializing the EVM? Are you using SBL or SPL flow?

Which MCU+SDK version are you using?

Regards,

Tushar

0 Rafael Silva over 1 year ago in reply to Tushar Thakur

Prodigy 20 points

Hi Tushar,
Are you using SBL or SPL flow? SBL
Which MCU+SDK version are you using? We trying to control this GPIO through Linux using gpiod library API. We are not using microcontroller MCU+SDK APIs.
Regards,
Rafael.

0 Tushar Thakur over 1 year ago in reply to Rafael Silva

TI__Guru 57618 points

Hi Rafael,

Thanks for sharing the above details.

Rafael Silva said:
We are using a custom SDK.

I am not sure what implementation you are using. I have checked the gpio_led_blink example at my end and I am able to control the LD3 with GPIO.

I am using MCU+SDK v 09.02.01.06. The EVM is initialized with SBL NULL binary.

Please refer below example project for more details.

Project - gpio_led_blink_am62x_sk_lp_m4fss0_0_freertos_ti_arm_clang.zip

Regards,

Tushar

0 Rafael Silva over 1 year ago in reply to Tushar Thakur

Prodigy 20 points

Hi Tushar,
I eddited my response regarding that point "Which MCU+SDK version are you using? We trying to control this GPIO through Linux using gpiod library API. We are not using microcontroller MCU+SDK APIs."
I hope this adds more info.
Regards,
Rafael.

0 Tushar Thakur over 1 year ago in reply to Rafael Silva

TI__Guru 57618 points

Hi Rafael,

You have mentioned that you are using SBL flow. Are you using SBL_OSPI_LINUX or using SD card to initialize the EVM?

Regards,

Tushar

0 Rafael Silva over 1 year ago in reply to Tushar Thakur

Prodigy 20 points

Hi Tushar,
we are using the internal emmc of the evk.
Regards,

Rafael.

0 Tushar Thakur over 1 year ago in reply to Rafael Silva

TI__Guru 57618 points

Hi Rafael,

I am routing your thread to one of our team member to further comment on linux side.

Please expect a reply in a day or two.

Regards,

Tushar

0 Anshu Madwesh over 1 year ago in reply to Tushar Thakur

TI__Mastermind 21075 points

Hi Rafael,

By default, the LED is set to heartbeat trigger for board demo purposes. See the device tree node here: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi?h=ti-linux-6.1.y#n118

There are a few ways to toggle the LED depending on your application.

1. In the device tree, You can change the LED Node's Function parameter do something else: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/include/dt-bindings/leds/common.h?h=ti-linux-6.1.y

2. In the device tree, change GPIO1_49 (LED GPIO) to a normal GPIO. Setting the GPIO high will turn on the LED & low will turn off the LED.

3. In SYSFS, change the trigger in '/sys/class/leds/'. The name of the LED is 'am62x heartbeat led'.

Thanks,

Anshu

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AM625: Test GPIO leds