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Change eMMC operating mode to HS200

Question asked by NIRMAL LUHANA on Sep 16, 2019
Latest reply on Oct 1, 2019 by gusarambula
Branched to a new discussion



Release: Yocto-Sumo (4.14.78_1.0.0_GA)

Board: i.MX8MQ based custom board


We designed iMX8MQ based custom board and used eMMC as booting option.

Right now, our eMMC is operated in HS400 mode as mentioned in kernel debug logs.

root@imx8mqpicoitx:~# cat /sys/kernel/debug/mmc0/ios
clock:          200000000 Hz
actual clock:   200000000 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:    10 (mmc HS400)
signal voltage: 1 (1.80 V)
driver type:    0 (driver type B)


We want to change eMMC operating mode to HS200.

So, for that which changes we have to change in dts file or in eMMC driver source?


Best regards,