Control SDMMC1 frequency?

Hi, is it possible to control the frequency of the SDMMC1 interface, as on RPi through the overclock parameter to the sdhost overlay?

Also, is it possible to use 1-bit SD mode?

hello eben.olson,

actually, I had never tried to change the protocol to SD mode for testing.
according to Tegra X1 (SoC) Technical Reference Manual, and please check the [SD/MMC CONTROLLER] chapter. your request was list as supported.

please have a try to modify uhs-mask in the device tree to change the protocol, you might also refer to L4T sources, and check below for more details.
thanks

$l4t-r32.2/public_sources/kernel/kernel-4.9/drivers/mmc/host/sdhci-tegra.c