• Evan Green's avatar
    dt-bindings: phy-qcom-qmp: Add UFS PHY reset · 95cee0b4
    Evan Green authored
    Add a required reset to the SDM845 UFS phy to express the PHY reset
    bit inside the UFS controller register space. Before this change, this
    reset was not expressed in the DT, and the driver utilized two different
    callbacks (phy_init and phy_poweron) to implement a two-phase
    initialization procedure that involved deasserting this reset between
    init and poweron. This abused the two callbacks and diluted their
    purpose.
    
    That scheme does not work as regulators cannot be turned off in
    phy_poweroff because they were turned on in init, rather than poweron.
    The net result is that regulators are left on in suspend that shouldn't
    be.
    
    This new scheme gives the UFS reset to the PHY, so that it can fully
    initialize itself in a single callback. We can then turn regulators on
    during poweron and off during poweroff.
    Signed-off-by: default avatarEvan Green <evgreen@chromium.org>
    Reviewed-by: default avatarRob Herring <robh@kernel.org>
    Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
    Signed-off-by: default avatarKishon Vijay Abraham I <kishon@ti.com>
    95cee0b4
qcom-qmp-phy.txt 6.7 KB