how to implement imx6ull interface to SDIO3.0 module?

actel — Tue, 25 Dec 2018 03:12:22 GMT

Hello,

My custom boards implement SD0 to boot up and SD1 to interface to wifi module. My wifi module support SD3.0 spec. So I provide 1.8v to sdio signals of wifi module. Meanwhile I also notice NVCC_NAND from imx6ull should be connected with 1.8v.

after boot up, I noticed kernel found a new high speed SDIO card but not a ultra high speed SDIO card.

After I ran "cat /sys/kernel/debug/mmc1/ios", I got that system found a sd2.0 card. That's a problem.

imx6ull14x14evk login: root
root@imx6ull14x14evk:~# cat /sys/kernel/debug/mmc1/ios
clock:       50000000 Hz
actual clock:   44000000 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:   2 (4 bits)
timing spec:   2 (sd high-speed)
signal voltage:   0 (3.30 V)
root@imx6ull14x14evk:~#

My dts is almost the same as imx6ull-14x14-evk.dts. What else should I be concerned?

The log file and dts file are attached.

Thanks.

Joe

Re: how to implement imx6ull interface to SDIO3.0 module?

joanxie — Thu, 10 Jan 2019 04:29:31 GMT

refer to the 4.9.88 bsp release note:

For i.MX 6ULL, the existing errata
ERR010450, EMMC HS200, and SD/SDIO
3.0 SDR104 at 1.8 V can only work below
or equal to 150 MHz. EMMC DDR52 and
SD/SDIO DDR50 at 1.8 V can only work
below or equal to 45 MHz.

i.MX Processorsのトピックhow to implement imx6ull interface to SDIO3.0 module?

how to implement imx6ull interface to SDIO3.0 module?

Re: how to implement imx6ull interface to SDIO3.0 module?