Hi,
On IMX6ULL I have set the clock for eMMC to 50Mhz but when I list the clocks in the linux kernel. It's written : (I can measure 33 Mhz also with the scope).
cat /sys/kernel/debug/mmc1/ios
clock: 52000000 Hz
actual clock: 33000000 Hz
vdd: 21 (3.3 ~ 3.4 V)
bus mode: 2 (push-pull)
chip select: 0 (don't care)
power mode: 2 (on)
bus width: 3 (8 bits)
timing spec: 8 (mmc DDR52)
signal voltage: 0 (3.30 V)
driver type: 0 (driver type B)
Below my dtsi part with the usdhc2 node :
&usdhc2 {
pinctrl-names = "default";
pinctrl-0 = <&PINS_USDHC2>;
bus-width = <8>;
no-1-8-v;
broken-cd;
keep-power-in-suspend;
wakeup-source;
status = "okay";
};
Why the clock is blocked to 33Mhz ? It could produce looses in terms of performances.
Guillaume
