Hi,
We are working on custom carrier board for Jetson Nano module.
The sdhci@700b0400 port cannot work proerly at U-Boot environment.
This port is assigned as microSD Slot.
And this sdhci port have already ported at Linux Kernel and works fine.
Specifically, Card Detect/ VDD Pin assigned as GPIO works normally, but CLK, CMD Pin does not oscillate it at all.
I debugged U-Boot mmc driver [drivers/mmc/tegra_mmc.c] and confirm that it accessed the address range of 0x700b0400.
And In dts, sdhc@700b0400 status is defined as “okay”.
sdhci@0,700b0400 { /* SDMMC3 for SD card */
status = "okay";
cd-gpios = <&gpio TEGRA_GPIO(Z, 2) GPIO_ACTIVE_LOW>;
power-gpios = <&gpio TEGRA_GPIO(E, 6) GPIO_ACTIVE_LOW>;
bus-width = <4>;
};
Still, from the result that I probed Pin by the Logic Analyzer, CLK,CMD does not seem to work and always “LOW”.
What kind of thing is considered as the cause that CLK,CMD does not oscillate in U-Boot ?
And has anyone enabled sdhc@700b0400 as SDCard in U-Boot?
Could you give me some advice about this problem? Thanks.