Code tags added.
1. Don't write fixups out by hand like this - it's very fragile, and dtc may overwrite them or otherwise interfere. Instead, use references to labels and let the compiler do the rest.
2. I don't know where you got the 0x21 in "clocks = <0xffffffff 0x00000021>;", but I think it's nonsense. The DT bindings for the BCM2835 clocks says it is BCM2835_PLLA_CCP2, whereas you want BCM2835_CLOCK_EMMC (28).
3. Don't expect all relevant kernel log entries to contain the string "mmc" - try "dmesg -l err,warn".
4. Be a bit more curious - you show that ls /sys/class/mmc_host/mmc1 exists, but not what it contains.
Here's a better version to try:
1. Don't write fixups out by hand like this - it's very fragile, and dtc may overwrite them or otherwise interfere. Instead, use references to labels and let the compiler do the rest.
2. I don't know where you got the 0x21 in "clocks = <0xffffffff 0x00000021>;", but I think it's nonsense. The DT bindings for the BCM2835 clocks says it is BCM2835_PLLA_CCP2, whereas you want BCM2835_CLOCK_EMMC (28).
3. Don't expect all relevant kernel log entries to contain the string "mmc" - try "dmesg -l err,warn".
4. Be a bit more curious - you show that ls /sys/class/mmc_host/mmc1 exists, but not what it contains.
Here's a better version to try:
Code:
/dts-v1/;/plugin/;/ {compatible = "brcm,bcm2835";fragment@0 {target = <&mmcnr>;__overlay__ {status = "disabled";};};fragment@1 {target = <&mmc>;sdio_ovl: __overlay__ {clocks = <&clocks 28>;clock-names = "emmc";pinctrl-names = "default";pinctrl-0 = <&sdio_ovl_pins>;non-removable;bus-width = <4>;status = "okay";};};fragment@2 {target = <&gpio>;__overlay__ {sdio_ovl_pins: sdio_ovl_pins {brcm,pins = <22 23 24 25 26 27>;brcm,function = <7>;brcm,pull = <0 2 2 2 2 2>;};};};fragment@3 {target-path = "/aliases";__overlay__ {mmc1 = "/soc/mmc@7e300000";};};__overrides__ {poll_once = <&sdio_ovl>, "non-removable?";bus_width = <&sdio_ovl>, "bus-width:0";sdio_overclock = <&sdio_ovl>, "brcm,overclock-50:0";};__fixups__ {clocks = "/fragment@1/__overlay__:clocks:0";};};Statistics: Posted by PhilE — Wed Feb 18, 2026 9:46 am