Hi,
Have someone got any idea about the method to access PCMCIA attribute space .
We tried it using io_p2v but we had segmentation faults.
Regards
Harsha
Nicolas Pitre wrote:
> On Fri, 5 May 2000, Chien-Min Lee wrote:
>
> >
> > >> However, if we use the physical address 0x91xxxxxx, after the
> > >> transform of io_p2v(0x91xxxxxx), it can not get the original physical
> > >> address by io_v2p.
> >
> > >Yes. All the virtual->physical and physical->virtual macros are only valid
> > >for RAM areas, not general IO.
> >
> > Does this mean that these two macros are useless!??
> > What address type(physical or virtual) do we use to access the registers of
> > peripheral control modules??
>
> You really don't have to bother about virtual or physical location of
> registers. If you want to clear some GPIOs, simply use
>
> GEDR |= (1<<x); /* set GPIO x direction for output */
> GPCR = (1<<x); /* set GPIO x low */
> val = (GPLR & (1<<y)); /* read GPIO y level (zero or not) */
>
> where x and y are your GPIO numbers. If you want to play with the memory
> control register, simply use MECR like:
>
> MECR = (MECR & (some_bits)) | some_other_bits;
>
> All those peripheral registers are defined in include/asm/arch/SA-1100.h.
> You should use them and not care about where and how they are mapped.
>
> Nicolas
>
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