DRA821U: GPIO Status

Hi Balkis,

Are you booting with Linux or RTOS?

Thanks,

Neehar

HI Neehar, 

We are working om LINUX.

Regards,

Balkis

Hi Balkis,

Thanks for this information, let me look into this and get back to you.

Thanks,

Neehar

Hi Neehar,

Do I have any input on the above request?

Regards,

Balkis

Hi Balkis,

Will you be changing the GPIO value within your application?

If not, you may use gpio-hog within the dts or the LED driver to set the GPIO value to high or low on boot.

Thanks,

Neehar

HI Neehar,

I have probed WKUP_GPIO0_84 without any software programmed, observed always high. As per our H/W the WKUP_GPIO0_84 should low even without any S/W then why DTS settings need to taken care ?

Hi Balkis,

Balkis Mahammad said:

I have probed WKUP_GPIO0_84 without any software programmed, observed always high.

What do you mean by "without any software programmed"? Does that mean before booting the board with Linux?

You are using a custom board correct?

Thanks,

Neehar

Yes, without booting WKUP_GPIO0_84 is observed high.

Hi Balkis,

Balkis Mahammad said:

how can i make this IO low during power up?

What is your use case for this? If the pin is seen as high before the board is booted, is it affecting the functionality of your application?

Thanks,

Neehar

Hi Neehar,

Yes, i don't need to worry about this level when it is not booted, but even when the board boots i see these pins high. But as per my requirement when it boots it should be low.
This IO am using as power control of SD signal level translator, at initail board boots this signal to be low, which makes SD signal at SD connector side 3.3V level, but this signal is high in uboot until i give command "mmc dev 1"

Hope you got point here why am I worried about the level of signal at bootup.

Regards,

Balkis

Hi Balkis,

Within your board schematic, do you use pull-up or pull-down resistors for each of the WKUP_GPIO signals?

Thanks,

Neehar

For  WKUP_GPIO0_84 clock has 10K pulldown in my design and even without this pulldown I see always high.

Regards,

Balkis

Hi Balkis,

Do you have the same pull-down resistor configuration and observations with WKUP_GPIO0_14 and WKUP_GPIO0_15?

Thanks,

Neehar

HI Neehar,

No, there is no pulldown resistor in WKUP_GPIO0_14 and WKUP_GPIO0_15 IOs and during probing these signal are always low.

Regards,

Balkis

Hi Balkis,

What I/O is WKUP_GPIO0_84 utilized to drive?

Balkis Mahammad said:

 WKUP_GPIO0_84 clock

Did this mean used to generate a clock?

Thanks,

Neehar

No, its not clock. It was typo

Hi Balkis,

I will look into this further and get back to you.

Thanks,

Neehar

Thank you Neehar,

Requesting you to support on this at earliest, as we are on the final stage of releasing our design and this is critical for us to forward ahead.

Regards,

Balkis

Hi Neehar,

Any update?

Hello, 

Our assigned engineer is out of office. Please expect a delay in response. Thanks for your patience.

Regards,
Sarabesh S.

HI Team,

Do I have any input on above query?

The assigned expert is still out of office. He will be available later in the week.

Thank you,
Sarabesh S. 

Hi Balkis,

Is there a reason why WKUP_GPIO0_84 is designed differently than WKUP_GPIO0_14 and WKUP_GPIO0_15?

Thanks,

Neehar