Linux/PROCESSOR-SDK-AM335X: Disabling GPIO init in kernel

Nithin Krishnan

Tool/software: Linux

Hi,

I am trying to modify device tree (am335x-boneblack.dts) for disabling initialization of gpio1[18]. I am succeeded with disabling whole gpio1 but I want to disable initialization of single port ie, gpio[18] during kernel startup. Is their any way to do that ??

Thanks and regards,

Krishnan

over 7 years ago

0 Yordan Kovachev over 7 years ago

TI__Guru**** 161600 points

Hi,

What do you mean disable the port? You can just set the pinmux so that it configures something different from gpio1[18] on the device pad.

Best Regards,
Yordan

0 Nithin Krishnan over 7 years ago in reply to Yordan Kovachev

Prodigy 20 points

Hai Yordan,

I have set gpio1 [18] high in spl(MLO). During the kernel boot up gpio are reinitialised so the pin goes to active low. Here I want to remove reinitialisation of particular gpio during boot so that the particular pin remains always high during boot up process .

Regards ,

Krishnan

0 Yordan Kovachev over 7 years ago in reply to Nithin Krishnan

TI__Guru**** 161600 points

Do you have the gpio1[18] pinmuxed in the linux kernel (your dts file)? I think if you just have the controller enabled (status = "okay") and you don't touch the pinmux for gpio1[18] you should have the value from MLO throughout the boot process. Also make sure that u-boot does not modify the gpio1[18] pinmux & gpio controller settings as well.

Best Regards,
Yordan

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Linux/PROCESSOR-SDK-AM335X: Disabling GPIO init in kernel