MMC/SD Speed Settings/Setup in Device Tree

I’d like to run my SD card speed slower than the default 50MHz; I’ve looked at
and it seems there is a way to do this with the device tree.

Does anyone have experience with this? I’ve done device tree work before, but not in this area.


There is a max-frequency specification in the mmc device-tree:


Thanks! Looks like the default range is 400kHz–200MHz

So if I wanted to do an overlay…is there a baseline overlay that affects the mmc that I can start with? I have used them for other peripherals like i2c, pwm, and encoders.