Thanks, thats fantastic, thats the kind of stuff I need to get me
going. One thing that shocked me was that the RDY line is also a
GPIO, I've not seen bus control lines multitasking like that before,
I'll have to check that thats set up right first. Pcb is progressing
well....I'm off to read the smc91x source code.
On 12/10/05, Craig Hughes <craig@...> wrote:
> On Oct 11, 2005, at 1:37 PM, George Francis wrote:
> > I'm in the process of something similar. I'd be interested to know
> > how much use an existing driver would be with custom hardware.
> > I'm laying out a pcb for a quick test of a camera chip (OV7620). One
> > of the problems with this kind of stuff is that the data is a constant
> > (fairly high) data rate, so I'm using a FIFO buffer to store a few
> > lines of image, then an ISR can read them in at a high rate. That way
> > the processor is only tied up for short bursts.
> It should then be fairly easy to hook the buffer up to the PXA,
> following the schematics for the etherstix or any of the netstix.
> You basically end up with some IO port on the PXA for one of the chip-
> selects connected to the IO device, then from the PXA's point of
> view, you just read a byte/halfword/word (depending on what the
> device wants to do) at a time from what to the PXA looks like
> memory. Oh, there's one other step which is you have to configure
> the PXA memory controller to tell it the specs of the device you're
> connecting. Normally that's just a matter of taking the device's
> datasheet, and reading off the numbers that the Intel configuration
> tool wants. The Intel tool then will spit out a value which you can
> stick in (iirc) MDCFG in the u-boot code to initialize things. Then
> your linux driver will have to allocate a resource for the memory
> address, then you can just read/write to the device. Of the device
> drivers the 'stix already uses, the smc91x one is probably easiest to
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