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mmc — MultiMediaCard and SD Card bus driver
The mmc driver implements the MMC and SD Card bus. The mmc driver supports all MMC and SD bridges in the system. All SD or MMC cards in the system attach to an instance of mmc. The mmc bus typically has only one slot, and only memory cards. MultiMediaCards exist only in memory. SD Cards exist as memory, I/O, or combination cards.
at91_mci(4), mmcsd(4), sdhci(4) SD Specifications, Part 1, Physical Layer, Simplified Specification. The MultiMediaCard System Specification.
SDIO cards currently do not work.