modifying registers in AM437x

Rohit

Hi,

I was wondering how to set register values for the AM437x via code.
I know it can be done via jtag, however I wanted to set register values via code so it is permanent in the build.
If anyone knows of the right way to change any register value of AM437x, please do let me know.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi,

What code are you asking about? Linux or something else? Can you provide more information?

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

Intellectual 370 points

Hi Biser,
I was wondering how to apply register values from the u-boot code or from the kernel code (like in dts file). I am using android kitkat with SE Linux kernel.

So would I need to add a line like: writel(<value>, &<register_name>); into any of the files? I am familiar with the writel API but do not know the correct location, so as to write into registers of AM437x.

0 Yordan Kovachev over 10 years ago in reply to Rohit

TI__Guru**** 161600 points

Hi Rohit,

I suggest you use the __raw_write() function or the write function defined in the corresponding module's driver. The driver itself is the correct place to write register values, not dts or any other file.

Have in mind that if you are trying to write register values within kernel space you need to use ioremap() function to remap the physical reg address to the kernel memory space. No need for remapping the address within u-boot code.

Best Regards,
Yordan

0 Rohit over 10 years ago in reply to Yordan Kovachev

Intellectual 370 points

Hi Yordan,
Oh I see.. got it.
I think the only thing missing was ioremap(). Thanks for the info.

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modifying registers in AM437x