If there is a kernel module in Linux to access the registers for DM6467

jim xu

Dear All,

I am just wondering if there is a kernel module in Davinci Linux OS that allow me to access all the register in DM6467? is GPIO lib can do that? Thanks.

Jim

over 13 years ago

0 Todd Fischer98 over 13 years ago

Intellectual 320 points

Hi Jim,

You can use busybox devmem to access hardware registers from user space.

You can control GPIOs using sysfs. You can read about it at

https://www.ridgerun.com/developer/wiki/index.php/How_to_use_GPIO_signals

Todd

0 jim xu over 13 years ago in reply to Todd Fischer98

Intellectual 560 points

Todd,

Thanks. the busybox version of devmem is a utility, I tried it, but seems not reliable, sometimes, the value get into register correct, sometimes, it doesn't, I don't know if something is missing here. Are there any other tools?

Jim

0 jim xu over 13 years ago in reply to jim xu

Intellectual 560 points

I just retested again, and found out that devmem2 cannot write the value to given register, but can read the value from any given register, this means that we don't have write access, but read access to the register, is there any lock mechanism to lock the resource before to write it? Thanks.

0 Kyle Manna over 13 years ago in reply to jim xu

Intellectual 420 points

jim xu said:

I just retested again, and found out that devmem2 cannot write the value to given register, but can read the value from any given register, this means that we don't have write access, but read access to the register, is there any lock mechanism to lock the resource before to write it? Thanks.

You are in fact correct. I've seen little documentation about accessing the register in supervisor mode other then what I've stumbled upon. Someone at TI wrote a module to do exactly what you want to do. I haven't tested it as I've resorted to using JTAG for reconfiguring those registers.

Check it out:

SVN repository: https://gforge.ti.com/gf/project/omapreg_debug/scmsvn/?action=browse&path=%2Ftrunk%2F

Project: https://gforge.ti.com/gf/project/omapreg_debug/

0 jim xu over 13 years ago in reply to Kyle Manna

Intellectual 560 points

I tried to get the files from SVN repository, but failed, do you know if there is other link available? Thanks.

0 jim xu over 13 years ago in reply to Kyle Manna

Intellectual 560 points

The Debug tools is not working for DM6467, may work for OMAP. any tools for DM6467?

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If there is a kernel module in Linux to access the registers for DM6467