• Faiz Abbas's avatar
    ARM: dts: am57xx: Disable voltage switching for SD card · fb59ee37
    Faiz Abbas authored
    If UHS speed modes are enabled, a compatible SD card switches down to
    1.8V during enumeration. If after this a software reboot/crash takes
    place and on-chip ROM tries to enumerate the SD card, the difference in
    IO voltages (host @ 3.3V and card @ 1.8V) may end up damaging the card.
    
    The fix for this is to have support for power cycling the card in
    hardware (with a PORz/soft-reset line causing a power cycle of the
    card). Because the beaglebone X15 (rev A,B and C), am57xx-idks and
    am57xx-evms don't have this capability, disable voltage switching for
    these boards.
    
    The major effect of this is that the maximum supported speed
    mode is now high speed(50 MHz) down from SDR104(200 MHz).
    
    commit 88a74841 ("ARM: dts: am57xx-idk: Remove support for voltage
    switching for SD card") did this only for idk boards. Do it for all
    affected boards.
    Signed-off-by: default avatarFaiz Abbas <faiz_abbas@ti.com>
    Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
    fb59ee37
am57xx-beagle-x15-revc.dts 893 Bytes