> Hi, all.
> SPI seems to be a reasonable local bus for future stuff. Low pin count,
> reasonable bitrate, a fair and growing number of SDIO peripherals, and SD
> cards are a reasonable way of adding storage.
> The EP9302 on Airship only supports the one-bit SDIO interface, but
> PXA27x on Balloon3 has the full thing.
> Using SPI as the link between the propellor(s) on Airship and the EP9302
> has charm - the propellor can be the master, which will allow us to run
> the bus as hard as possible (since propellor has no hardware SPI, it ought
> to generate the clock).
> Is there support in the Linux flavours we're tending to use for SD and
> SDIO stuff?
There is linux support for MMC that all SD cards must support. I am unclear
whether SDIO can exist in extended MMC mode or not. The problem is legal
stuff with SD protocols.
See
http://help.lockergnome.com/linux/RFC-MMC-driver-model-ftopict365237.html
for some SDIO integration chatter.
Current stock kernel has MMC and MMC on MMC/SD/SDIO controllers but I am
unclear if this extends to SDIO support. I think it doesn't.
See
http://www.arasan.com/html4pdf/sdio_nex_driver_overview.php for a
commercial linux implementation on its own hardware and a review at
http://linuxdevices.com/news/NS3979314345.html
Nick
>
> Steve
>
>
>
> _______________________________________________
> Balloon mailing list
> Balloon@balloonboard.org
> http://balloonboard.org/mailman/listinfo/balloon
>
(text/plain)