wl1251
wl1251 is a driver for TI wl1251 802.11 chipset designed for embedded devices, supporting SDIO and SPI busses. Adding support 1253 (the 5 GHz version) should be relatively easy.
More information here: http://focus.ti.com/general/docs/wtbu/wtbugencontent.tsp?templateId=6123&navigationId=12025&contentId=4645