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RTSX(4) Device Drivers Manual RTSX(4)

Realtek SD card reader

rtsx* at pci?
sdmmc* at rtsx?

The rtsx driver provides support for the Realtek RTS5209, RTS5227, RTS5229, RTS522A, RTS5249, RTS525A, RTL8402, RTL8411, and RTL8411B SD card readers.
The sdmmc(4) subsystem performs SD/MMC transactions to communicate with SD or SDHC devices inserted into the SD slot.

intro(4), sdmmc(4)

The rtsx driver first appeared in OpenBSD 5.3.

The rtsx driver was written by Stefan Sperling <stsp@openbsd.org>.

The rtsx driver does not support MS (Memory Stick) and xD (Extreme Digital) devices even though the hardware supports them.
Support for SDIO interrupts is not implemented.
September 6, 2017 OpenBSD-current