Linux/OMAPL138B-EP: PUPD access from kernel

Risto Hedman

Expert 1770 points

Part Number: OMAPL138B-EP
Other Parts Discussed in Thread: OMAPL138

Tool/software: Linux

Hi,

I need to activate some gpio pullups for while booting, which might be the easiest way to realize this in kernel code?

risto

over 8 years ago

0 Cvetolin Shulev-XID over 8 years ago

TI__Guru 65405 points

Hi Risto,

Could you specify what Linux kernel version you are using?

BR
Tsvetolin Shulev

0 Risto Hedman over 8 years ago in reply to Cvetolin Shulev-XID

Expert 1770 points

Hi Tsvetolin,

Linux is 3.3.0

BR risto

0 Cvetolin Shulev-XID over 8 years ago in reply to Risto Hedman

TI__Guru 65405 points

Risto,

You can configure pinmux settings for a GPIO in the u-boot or in the kernel. You can find detailed description about how to do this in the linked article:
elinux.org/BeagleBoardPinMux

BR
Tsvetolin Shulev

0 Risto Hedman over 8 years ago in reply to Cvetolin Shulev-XID

Expert 1770 points

Tsvetolin,

Sorry but I did find properties described in that link for OMAPL138?? Only registers PUPD_ENA and PUPD_SEL were described in spruh77a and sprs5861. IPU/IPD registers were referred in thread e2e.ti.com/.../113557, sprugm75e I did not find ??

During kernel boot I printed the contents of PUPD_ENA (def=0xFFFF.FFFF) and PUPD_SEL (def=0xC3FF.FFFF) and they were in their default values meaning that all possible pins are pulled up.

BR, risto

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Linux/OMAPL138B-EP: PUPD access from kernel