On Saturday 15 February 2014 12:27:33 Russell King - ARM Linux wrote: > On Sat, Feb 15, 2014 at 01:18:02PM +0100, Arnd Bergmann wrote: > > If a wlan adapter has both SPI and SDIO front-ends, the external > > dependencies (reset, clock, voltage, ...) will be the same, and > > from the kernel perspective the main difference is that SPI cannot > > be probed at all, while SDIO can be probed as long as the device > > is powered on already. > > Remember that MMC/SD/SDIO cards can be driven by either a MMC host > interface, or a SPI interface. Both are probe-able. I knew about MMC/SD cards being required to understand simple SPI, I wasn't sure about SDIO. My understanding however is that you have to use the mmc_spi host driver to actually use MMC/SD devices as a block device, and that requires having either a DT description for the host or an spi_board_info, which I would not consider discoverable. For spi-mode SDIO devices I'm assuming it's similar, except that you'd describe the actual SDIO device in the board info rather than create a fake SDIO controller. Still not discoverable unless I'm missing your point. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
