How to access physical memory from user space for MPC8260 chip

How to access physical memory from user space for MPC8260 chip

[suresh suresh]

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Hi,

I have to map physical memory to user space or kernel space. I am writing
driver for MPC8260 chip and I want to know how to map any 32-bit address
space to user space and kernel space.

Please give me some ideas.

Thanks,
Suresh

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RE: How to access physical memory from user space for MPC8260 chip

[Fillod Stephane]

suresh suresh wrote:
>I have to map physical memory to user space or kernel space. I am
writing >driver for MPC8260 chip and I want to know how to map any
32-bit address >space to user space and kernel space.

Your question is a linuxppc-embedded FAQ. User-land access is documented

in Denx's FAQ[1], and accessible through shorter URL[2]. For more=20
information, please follow this thread[3] (not ppc specific actually).

[1]
http://www.denx.de/twiki/bin/view/PPCEmbedded/DeviceDrivers#Section_Acce
ssingPeripheralsFromUserSpace
[2] http://tinyurl.com/6c7th
[3] http://article.gmane.org/gmane.linux.ports.ppc.embedded/5053

In kernel land, ioremap() is all you need.

Don't forget to use the 'eieio' asm instruction if you want explicit=20
I/O ordering.

Best Regards,
--=20
Stephane, the userland ioremap bot

RE: How to access physical memory from user space for MPC8260 chip

[Misbah khan]

Physical address you can map to  kernel space using ioremap() function 
but you are not clear whether you want to map it to the user space / kernel
space. To map kernel space to user space you should use mmap() functionality
in your driver.

I hope you got the answer to what you were expecting else send the clear
query

regard 
misbah


Fillod Stephane wrote:
> 
> suresh suresh wrote:
>>I have to map physical memory to user space or kernel space. I am
> writing >driver for MPC8260 chip and I want to know how to map any
> 32-bit address >space to user space and kernel space.
> 
> Your question is a linuxppc-embedded FAQ. User-land access is documented
> 
> in Denx's FAQ[1], and accessible through shorter URL[2]. For more 
> information, please follow this thread[3] (not ppc specific actually).
> 
> [1]
> http://www.denx.de/twiki/bin/view/PPCEmbedded/DeviceDrivers#Section_Acce
> ssingPeripheralsFromUserSpace
> [2] http://tinyurl.com/6c7th
> [3] http://article.gmane.org/gmane.linux.ports.ppc.embedded/5053
> 
> In kernel land, ioremap() is all you need.
> 
> Don't forget to use the 'eieio' asm instruction if you want explicit 
> I/O ordering.
> 
> Best Regards,
> -- 
> Stephane, the userland ioremap bot
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
> 
> 

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