SDIO support coming [LWN.net]

The Secure Digital Input/Output specification enables the creation of SD cards which handle tasks beyond the simple storage of bits, which is what SD has traditionally been used for. The SD Association SDIO page shows some cute pictures with SDIO network adapters, cameras, GPS receivers, fingerprint recognizers, and a strangely disturbing image of a scanner glued directly to an SD card. As small gadgets with SD slots become more prevalent, one can imagine a number of uses for peripherals which can be attached to those slots. Since many of those gadgets run Linux, it would be nice to have proper support for SDIO devices in the mainline kernel. Unfortunately, like much of the SD Association's work, SDIO has been a realm of proprietary specifications and implementations.

That would appear to be about to change, however: Pierre Ossman has sent out an announcement of interest:

I am happy to announce that SDIO support will soon be a standard feature in Linux. No more proprietary stacks with all the troubles (legal and technical) that go with them.

The new SDIO stack, written by Pierre and Nicolas Pitre, is in a fairly complete state with all the sorts of bus-level support that driver writers have come to expect. There is one driver (for GPS interfaces) available now; it is expected that others will show up shortly. If all goes well, expect the new SDIO stack to be ready for 2.6.24.

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SDIO support coming

Posted Jul 26, 2007 10:57 UTC (Thu) by dvrabel (subscriber, #9500) [Link]

SDIO is not just for plug-in cards; it's rapidly becoming a common "high speed" chip interconnect in embedded devices (like mobile phones or media players) for things like WiFi etc.

SDIO support coming

Posted Jul 26, 2007 19:18 UTC (Thu) by ken (subscriber, #625) [Link]

In the spec they brag about 100Mb that is not "high speed"

SDIO support coming

Posted Jul 27, 2007 8:42 UTC (Fri) by dvrabel (subscriber, #9500) [Link]

In the embedded space where the alternatives are SPI (20 Mbit/s), UART (8 Mbit/s) and I2C (400 kbit/s), 100 Mbit/s is fast. Interconnects like PCI, PCIe and USB2.0 consume too much power or require too many pins.

SDIO support coming

Posted Aug 3, 2007 7:57 UTC (Fri) by HalfMoon (guest, #3211) [Link]

SPI (20 Mbit/s)

The fastest SPI chips I've seen are 70 Mbits, but it's true that most of them aren't quite that speedy. On the other hand, most SDIO cards aren't that fast either (and don't use 4bit parallel signaling) ... in fact, every SDIO card supports SPI.