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  • Hannes Schmelzer's avatar
    mmc: sdhci: add SDHCI_QUIRK_BROKEN_HISPD_MODE · 47a63e66
    Hannes Schmelzer authored and Jaehoon Chung's avatar Jaehoon Chung committed
    Some IP-core implementations of the SDHCI have different troubles on the
    silicon where they are placed.
    
    On ZYNQ platform for example Xilinx doesn't accept the hold timing of an
    eMMC chip which operates in High-Speed mode and must be forced to
    operate in non high-speed mode. To get rid of this
    "SDHCI_QUIRK_BROKEN_HISPD_MODE" is introduced.
    
    For more details about this refer to the Xilinx answer-recor #59999
    https://www.xilinx.com/support/answers/59999.html
    
    
    
    This commit:
    - doesn't set HISPD bit on the host-conroller
    - reflects this fact within the host-controller capabilities
    
    Upon this the layer above (mmc-driver) can setup the card correctly.
    
    Otherwise the MMC card will be switched into high-speed mode and causes
    possible timing violation on the host-controller side.
    
    Signed-off-by: default avatarHannes Schmelzer <oe5hpm@oevsv.at>
    
    Signed-off-by: default avatarHannes Schmelzer <hannes.schmelzer@br-automation.com>
    47a63e66