AM335X - How could I change pinmux on the fly in user space in Processor SDK

kuanlun chiu

Prodigy 140 points

Dear Sirs,

In previous SDK 6.0, I can modify dedicated pinmux through /sys/kernel/debug/omap_mux/ in user space.

But I cannot find such path in Processor SDK v1.0.3.

Did I miss any config or is there other way to do this?

Thanks.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi,

You can write directly the value in the pinmux register using devmem2 command.

0 kuanlun chiu over 10 years ago in reply to Biser Gatchev-XID

Prodigy 140 points

Hi, Biser,

Thanks for your reply.
But I cannot get it work with devmem2 command.
It is always changed back to original setting somehow.
I tried to modify 0x44e108e8 (lcd_pclk) to set it as GPIO mode and devmem2 seems writing successfully.
But the register is left unchanged when I read it again.

root@am335x-evm:~# devmem2 0x44e108e8 w 7
/dev/mem opened.
Memory mapped at address 0xb6f39000.
Read at address 0x44E108E8 (0xb6f398e8): 0x00000000
Write at address 0x44E108E8 (0xb6f398e8): 0x00000007, readback 0x00000007
root@am335x-evm:~# devmem2 0x44e108e8
/dev/mem opened.
Memory mapped at address 0xb6f46000.
Read at address 0x44E108E8 (0xb6f468e8): 0x00000000
root@am335x-evm:~#

0 Steve Kipisz over 10 years ago in reply to kuanlun chiu

TI__Genius 15510 points

You cannot use devmem2 to change any bits in the Control Module. Only kernel code can change it.

Steve K.

0 kuanlun chiu over 10 years ago in reply to Steve Kipisz

Prodigy 140 points

Hi, Steve,

Thanks, but I want to know is there any way that I can change pinmux dynamically in user space in Processor SDK?
Like what I can modify debugfs /sys/kernel/debug/omap_mux/lcd_pclk directly in SDK 6.0

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AM335X - How could I change pinmux on the fly in user space in Processor SDK