Hi all,


I have been spinning my wheels for two days trying to discover how to enable MMC1 on a CM3. This is the one on GPIO22-27. I can boot Rasbian on the CM3 and it inits the MMC1 and its pins just fine. I can read/write to my SD card from it etc. However, when I build yocto it leaves the GPIOS22-27 in gpio mode and does not set them to MMC1 mode.  I have tried changing the device tree as described here:

https://stackoverflow.com/questions/44702426/how-to-setup-an-own-device-tree-for-a-raspberrypi-in-yocto

That compiles and add the .dtbo to my build, but still the GPIOS are not set to MMC1 mode.

cat /sys/kernel/debug/pinctrl/*gpio*/pinmux-pins
Pinmux settings per pin
Format: pin (name): mux_owner gpio_owner hog?
....

pin 22 (gpio22): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 23 (gpio23): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 24 (gpio24): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 25 (gpio25): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 26 (gpio26): (MUX UNCLAIMED) (GPIO UNCLAIMED)
pin 27 (gpio27): (MUX UNCLAIMED) (GPIO UNCLAIMED)

.....

I have looked at:

https://ralimtek.com/raspberry%20pi/electronics/software/raspberry_pi_secondary_sd_card/


Any ideas of where to look next to turn on the sdio would be appreciated!


Chuck