MPC5200B - Mapping Micrel Ethernet Controller Chip

Grant Likely grant.likely at secretlab.ca
Wed Nov 14 04:16:54 EST 2007


On 11/13/07, Sri nava kala devi Valteti, TLS-Chennai
<srinavakalav at hcl.in> wrote:
>
> Hi
> Thank you for your response.
> > Are you *sure* it's mapped at physical address 0xe0000000? (ie. have
> >you verified that you can access the device registers via u-boot or a
> >debugger?)
>
> Yes, We have accessed the Micrel chip via U-boot setting (Micrel Chips
> Base addres) 0xE0000000 to the CS1 Start address Register.
> The LP_CS1 pin is configured to access the chip in U-boot.
>
>
> LINUX:
> We also probed the CS1 signal and found some noise in the signal (but
> wasn't any kind of pulse). It might not be the actual Chip Select pulse.
> But in U-Boot, we are getting proper Chip Select pulse.

Most likely, something in the board setup routine (in Linux) is
fiddling with the CS settings (which it should not do).  If you u-boot
has it working, then it *should* just carry over to working in Linux.

>
> LINUX:
> The MBAR is mapped to default 0xF0000000 value. The BAT 2 settings in
> the "mpc52xx_set_bat" function, is set to map the 0xf0000000 area.
> Do we need to perform any similar BAT settings or any other settings to
> access the IO Device mapped at 0xE0000000 ?

No.  u-boot should be responsible for configuring the CS pins.  Once
the kernel takes over, you should only need to call ioremap() to get
access to the device.

mpc52xx_set_bat?  You must be using arch/ppc (which is depreciated).
Can you move up to a more recent kernel and use arch/powerpc instead?

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
grant.likely at secretlab.ca
(403) 399-0195


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