RE: [PATCH v2 3/3] mmc: add HS400 support for iMX7ULP

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> From: BOUGH CHEN
> Sent: Monday, April 29, 2019 4:56 PM
> Subject: [PATCH v2 3/3] mmc: add HS400 support for iMX7ULP
> 
> Add HS400 support for iMX7ULP B0.
> 
> According to IC suggest, need to clear the STROBE_DLL_CTRL_RESET before any
> setting of STROBE_DLL_CTRL register.
> 
> USDHC has register bits(bit[27~20] of register STROBE_DLL_CTRL) for slave sel
> value. If this register bits value is 0,  it needs
> 256 ref_clk cycles to update slave sel value. IC suggest to set bit[27~20] to 0x4,
> it only need 4 ref_clk cycle to update slave sel value. This will short the lock
> time of slave.
> 
> i.MX7ULP B0 will need more time to lock the REF and SLV, so change to add
> 5us delay.
> 
> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>

mmc: sdhci-esdhc-imx: add HS400 support for iMX7ULP

otherwise:
Reviewed-by: Dong Aisheng <aisheng.dong@xxxxxxx>

Regards
Dong Aisheng




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