• Ben Avison's avatar
    Change how we interpret SDIO device bus speed capability · cd4a1229
    Ben Avison authored
    It appears that not all SDIO devices report a sensible MAX_TRAN_SPEED in
    their CIS - for example, many Cypress chips report 500 kbit/s there whilst
    simultaneously reporting support for high-speed bus speed (i.e. 50 MHz) in
    the CCCR, which makes no sense.
    
    Infer from the wording in the spec (it talks about a *minimum* value for
    MAX_TRAN_SPEED for a Low-Speed card, but only of a single value for other
    cards - one which corresponds to a non-high-speed bus, but this might be a
    legacy of a realy old version of the spec) that the speed from the CIS is
    only supposed to apply to Low-Speed cards. There's a flag in the CCCR which
    indicates such cards.
    
    Version 0.20. Tagged as 'SDIODriver-0_20'
    cd4a1229