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scottellis / omap3-pwm

Kernel module to allow PWM control from userland
http://www.jumpnowtek.com
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Regarding PWM driver #2

Closed alexvatti closed 13 years ago

alexvatti commented 13 years ago

Hi Thanks for the info sharing,

i am facing the problem: root@overo:~# devmem2 0x48086038 w 0xFFFFFFEF
/dev/mem opened.Unhandled fault: external abort on non-linefetch (0x1018) at 0x8

Memory mapped at address 0x40020000.
Bus error

I have configured all pwm as output & mode 2 in u-boot level. In kernel ,i disabled lcd functionality & touch screen.

But still facing the problem

i am using overo com with summit board.

Awaiting for positive response. Thank you very much

scottellis commented 13 years ago

A little busy right now to setup a test. Here are two things you could look at.

  1. Check that CONFIG_OMAP_RESET_CLOCKS is not set in your kernel config. This is a power saving feature, one being disabling the PWM clocks.
  2. Make sure the timer isn't already running when you try to change the TMAR register. One way is to write 0 to the TCLR (0x48086024 for PWM10). This I'm not sure about. It might be okay to change the TMAR while the timer is running. I would have to check, but it is not something I have ever tried.
alexvatti commented 13 years ago

Thank you very much for fast response in spite of your busy schedule work. As you mentioned,i change the configuration

"Check that CONFIG_OMAP_RESET_CLOCKS is not set in your kernel config. This is a power saving feature, one being disabling the PWM clocks."

It is working fine, Thank you very much