Linux/AM5728: GPIO pin number calculation

vijay Patil

Intellectual 810 points

Part Number: AM5728

Tool/software: Linux

In one of the reference code the gpio pin of AM5728 is set as:

"echo 1 > /sys/class/gpio/gpio54/value"

I tried to found that pin in datasheet but i didnt found.

So will u please tell me which pin is this gpio54 , In which register bank and which pin number is this??

How to calculate pin number?

for eg. If i want to find gpio136 pin, so it is in which bank, which pin number?

Thanks and regards,

Vijay Patil

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

The software team have been notified. They will respond here.

0 Kemal R. Shakir over 7 years ago in reply to Biser Gatchev-XID

TI__Guru 55345 points

Hello Vijay,

Board documentation should in most cases cover what GPIOs are used for what purposes. However, those numbers are not always stable; GPIOs on a daughtercard might be different depending on the base board being used, or other cards in the stack. In such cases, you may need to use the gpiochip nodes (possibly in conjunction with schematics) to determine the correct GPIO number to use for a given signal.

I quote this from <Processor SDK>/board-support/linux-<version>/Documentation/gpio/sysfs.txt file.

Best regards,
Kemal

0 vijay Patil over 7 years ago in reply to Kemal R. Shakir

Intellectual 810 points

So will u please tell me which pin is this gpio54 , In which register bank and which pin number is this??
How to calculate pin number?

for eg. If i want to find gpio136 pin, so it is in which bank, which pin number?

Thanks and Regards.

Vijay Patil

0 Kemal R. Shakir over 7 years ago in reply to vijay Patil

TI__Guru 55345 points

It will depend on your device tree configuration. If you have all the gpio banks disabled except first gpio bank (1) and last (8) for instance, the gpio54 will be the 22-nd pin of gpio bank 8.

0 vijay Patil over 7 years ago in reply to Kemal R. Shakir

Intellectual 810 points

If I did not disabled the any gpio bank when what should be the pin number

0 Kemal R. Shakir over 7 years ago in reply to vijay Patil

TI__Guru 55345 points

It will depend on the board and the Processor SDK version you use on it. Which are they?

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Linux/AM5728: GPIO pin number calculation