Quantcast

Overo devmem2 bus error

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Overo devmem2 bus error

Robin Moss

Hi,

 

I’ve been looking around and fiddling but haven’t been able to fix this issue. I’m trying to get PWM working, I have some code that worked before on an Overo-Air but with my new one it doesn’t work.

 

Calling:

devmem2 0x48088024 w 0x00000000

Gives me a Bus error

 

I have google quite a few things and have tried the following:

•             CONFIG_OMAP_RESET_CLOCKS – Disabling this in the kernel config (via menuconfig)

•             ARCH_HAS_HOLES_MEMORYMODEL – This is enabled in the config

 

Just to make sure I'm actually compiling the kernel right (with new config)

 

Bitbake –c menuconfig virtual/kernel

cp ${OVEROTOP}/tmp/work/overo-angstrom-linux-gnueabi/linux-omap3-3.2-r103git/.config \

   ${OVEROTOP}/org.openembedded.dev/recipes/linux/linux-omap3/Overo/defconfig

Bitbake –c clean virtual/kernel

Bitbake virtual/kernel

Bitbake omap-console-image

 

Then I flash the nand with the compile images in:

${OVEROTOP}/tmp/work/deploy/glibc/image/Overo/

 

If anyone has any suggestions as it if I'm doing the build/config wrong or what I need to fix in my config I would really appreciate it.

 

Thanks

 


------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
gumstix-users mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gumstix-users
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Overo devmem2 bus error

Philipp Lutz
Hi Robin,

did you check out the following tutorial by Scott Ellis?
http://www.jumpnowtek.com/index.php?option=com_content&view=article&id=56&Itemid=63

There is some note regarding the devmem2 approach for kernel versions > 2.6.39
NOTE: The devmem2 procedure won't work with kernel 2.6.39 or greater. The source clocks for PWM are now disabled by default and have to be explicitly enabled before the timer registers can be accessed. The devmem2 steps below do not do this. Refer to the omap3-pwm driver and look for pwm_enable_clock() in pwm.c to see how to enable the clocks in a driver.
Hope that helps.
Btw.: the omap3-pwm driver works like a charm!

Cheers
Phil



-------- Original Message  --------
Subject: [Gumstix-users] Overo devmem2 bus error
From: Robin Moss [hidden email]
To: [hidden email]
Date: 08/28/2012 11:34 PM

Hi,

 

I’ve been looking around and fiddling but haven’t been able to fix this issue. I’m trying to get PWM working, I have some code that worked before on an Overo-Air but with my new one it doesn’t work.

 

Calling:

devmem2 0x48088024 w 0x00000000

Gives me a Bus error

 

I have google quite a few things and have tried the following:

•             CONFIG_OMAP_RESET_CLOCKS – Disabling this in the kernel config (via menuconfig)

•             ARCH_HAS_HOLES_MEMORYMODEL – This is enabled in the config

 

Just to make sure I'm actually compiling the kernel right (with new config)

 

Bitbake –c menuconfig virtual/kernel

cp ${OVEROTOP}/tmp/work/overo-angstrom-linux-gnueabi/linux-omap3-3.2-r103git/.config \

   ${OVEROTOP}/org.openembedded.dev/recipes/linux/linux-omap3/Overo/defconfig

Bitbake –c clean virtual/kernel

Bitbake virtual/kernel

Bitbake omap-console-image

 

Then I flash the nand with the compile images in:

${OVEROTOP}/tmp/work/deploy/glibc/image/Overo/

 

If anyone has any suggestions as it if I'm doing the build/config wrong or what I need to fix in my config I would really appreciate it.

 

Thanks

 



------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
gumstix-users mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gumstix-users
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Overo devmem2 bus error

Robin Moss
This post was updated on .
Thanks for letting me know.

I wrote a driver for it about 2 years ago on my old Gumstix in Python. Will look into getting it operational again, at least i now know what i need to look into.

Is there anyway to enable the ability to use an MMAP to control the servos again or is my only option to look at using the drivers?
Loading...