Hello Philip,
you wrote :
> I'm having difficulty with the SA1110 GPIO and mmap. The following code
> compiles and executes, however, the appropriate pin does not toggle as
> expected:
> .................................
Unless this changed from Kernel 2.2 to 2,4, I think the main problem is that
/dev/mem only maps physical *RAM* (0xc0000000 + xMb, possibly with holes in it
if you use several banks on an SA1110).
Thus you cannot use /dev/mem to map IO-Adresses to user space.
/dev/kmem probably does not work either.
Please be aware of another pitfall :
> /* Set the SC pin high */
> *GPSR |= 0x00000004;
GPSR (GP_Set_Register) and GPCR (GP_Clear_Register) are write-only registers
that are only written with a 1 for each bit that is to be set (GPSR) or cleared
(GPCR). Therefore,
GPSR |= 0x00000004;
probably works as expected (sets GPIO2), but
GPCR &= ~0x00000004;
would be a NOP, as as it reads 0 from the non-existent
read-Register and then writes all 0's to GPCR, which clears nothing.
Best regards,
Klaus
--
Mobotix AG
Klaus Borchers
Wingertsweilerhof 6
D-67724 Hoeringen
Germany
Tel: +49 (6302) 9223-88
Fax: +49 (6302) 9223-70
E-Mail: [EMAIL PROTECTED]
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