Messages in this thread | | | Date | Wed, 25 Jul 2007 23:30:52 +0400 | From | Sergei Shtylyov <> | Subject | Re: [PATCH 2/2] [POWERPC] MPC8349E-mITX: use platform IDE driver for CF interface |
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Scott Wood wrote:
>> Scott Wood wrote:
>>>> Also, what mmio-ide in the compat properly means in the context >>>> of ide_platform which is able to handle both port and memory mapped >>>> IDE.
>>> I/O-space is only valid in the context of PCI, ISA, or similar buses, >>> and >>> the bus-specific reg format indicates whether it's mmio-space or >>> io-space.
>> You could save time on lecturing me (and use it to look on the >> driver ;-).
> Sorry, I misread the question as being a mismatch between the > capabilities of the device binding and the driver, not about the > specific compatible name.
That too. :-)
> Something like "generic-ide" would probably be better.
I strongly disagree with "generic" part. The generic IDE could only be said of 1:1 I/O mapped IDE ports, not about this fancy mapping.
>>> What is board specific about a set of standard IDE registers at a given
>> The regisrer mapping used is highly non-standard.
> The gap between registers is nonstandard, but that's a fairly common > type of noncompliance in embedded-land, and probably merits being
That is only a common variation of embedded non-compliancy (which doesn't make it a compliancy. ;-) There are worse cases in the bi-endian land, even with the standard 8-bit regs and 1-byte stride. *Hopefully*, this driver could also support those...
> supported in a generic way. I wouldn't call it "highly" nonstandard.
Yeah, there are also 8250 "compatible" UARTs that use 32-bit memory accesses, and even worse -- with some registers mapped differently than on 8250 (those can't be called compatible by any means), yet 8250.c drives all of them. I'm not really sure it was such a good idea to merge, say Alchemy UART support into 8250.c.
> Is there some other non-standardness that I'm missing?
*Hopefully*, none. The original Kumar's driver pretended to handle byte-lane swapping too (but that was ugly :-).
>> We're already in board specific code, so why the heck not? :-)
>>> various ns16550-compatibles out there as well?
>> I never suggested that -- what I did suggest was make of_serial.c >> recognize certain chip types and register them with 8250 driver.
> What would be the advantage of maintaining a list of chips whose only
Nobody's talking about the advantages, just about the device tree accepted practices (which we've already tried to bypass with MTD node -- causing a lot of bashing until David Woodhouse came to help :-).
> difference is register spacing, rather than just using reg-shift and > being done with it?
Please read the linuxppc-dev archive's threads following form David's patches. Or maybe Segher could repeat this for you. ;-)
> -Scott
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