Problem reading and programming memory location...

neorf3k neorf3k at gmail.com
Thu Nov 14 00:48:24 EST 2013


Yes, that is a device on the lpb via an fpga. We  have tried to configure the chip select 4 configuration register at address MBAR + 0x0310, and it seems to be ok. what do you mean with “chip select parameters”?
We have been able to edit it in U-BOOT, and the board (that chip) now works…
The strange thing, is that when we read in linux, at that address, we see other content value…
Suggestions?

Thanks

Lorenzo

On 13/nov/2013, at 08:32 AM, Anatolij Gustschin <agust at denx.de> wrote:

> On Tue, 12 Nov 2013 20:23:20 +0100
> neorf3k <neorf3k at gmail.com> wrote:
> 
>> we have tried to read and program an 8bit register with 32bit address.
>> we have mapped it with: ioremap, kmalloc etc… and then using: outb,
>> iowrite8 etc.. but when we write to it, the value doesn’t change…
>> with other memory location is ok.
>> That is an 8 bit register, located at 0x10020000 in a mpc5200b
>> architecture. we are using kernel 2.6.33. 
>> what could be?
> 
> 0x10020000 is not in the internal register memory map, so it
> is probably a device on the LocalPlus bus. Did you configure
> the chip select parameters for this device and did you enable
> the associated chip select?
> 
> HTH,
> 
> Anatolij
> 



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