This isn't clear to me. The chip supports multiple protocols on the device side, and you're assuming that a particular protocol (one appropriate for flash devices) is the correct one? Whereas the shuttle_usbat driver assumes ATAPI is correct? Doesn't the USBAT02 chip provide some way to tell which protocol to use? Or do I have it all wrong?
I don't think so. Basically each usbat-specific command has a bit in the BRequest field which defines if you are working with EPP, EPP registers, ATA, or ISA.
In this case, both the hp8200 and the flash devices use the ATA access almost entirely (the hp8200 writes to some ISA registers during the init function, not really sure why..).
Unfortunately I don't have my reference documents at hand. Is IDENTIFY DEVICE an ATAPI command or (as I seem to remember) is it really an ATA command that was carried over? Isn't there a true ATAPI command you can use, such as INQUIRY?
I'm fairly new to this and am not too sure on the distinction between ATA and ATAPI. I'll have to do some reading up, but thanks for the suggestion :)
This is the doc I have been using when working with the flash devices: http://www.t13.org/project/d1410r3a-ATA-ATAPI-6.pdf
Specifically, I've looked at word 0 (signature), words 10-19 (serial number), words 23-26 (firmware revision), and words 27-46 (model number).
Unfortunately, all of these fields appear to be media-dependant, and suprisingly only 1 of my 4 CF cards produces the CF signature defined in the CF specs (0x848A), there is definately no consistency here. (Plus, the driver should ideally support connection when no media is present.)
Again, I'm stymied without the specs. Is there some ATA-level command you can use to find out whether a device supports ATAPI?
I'm not sure, but I don't think this would help much: both the hp8200 and the flash readers use the ATA/ATAPI transport. Or are you suggesting that the hp8200 implements ATA but not ATAPI?
Thanks for the ideas, Daniel
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