• Johan Hovold's avatar
    dt-bindings: phy: qcom,qmp-usb3-dp: fix sc8280xp binding · e1c4c543
    Johan Hovold authored
    The current QMP USB3-DP PHY bindings are based on the original MSM8996
    binding which provided multiple PHYs per IP block and these in turn were
    described by child nodes.
    
    The QMP USB3-DP PHY block provides a single multi-protocol PHY and even
    if some resources are only used by either the USB or DP part of the
    device there is no real benefit in describing these resources in child
    nodes.
    
    The original MSM8996 binding also ended up describing the individual
    register blocks as belonging to either the wrapper node or the PHY child
    nodes.
    
    This is an unnecessary level of detail which has lead to problems when
    later IP blocks using different register layouts have been forced to fit
    the original mould rather than updating the binding. The bindings are
    arguable also incomplete as they only the describe register blocks used
    by the current Linux drivers (e.g. does not include the PCS LANE
    registers).
    
    This is specifically true for later USB4-USB3-DP QMP PHYs where the TX
    registers are used by both the USB3 and DP parts of the PHY (and where
    the USB4 part of the PHY was not covered by the binding at all). Notably
    there are also no DP "RX" (sic) registers as described by the current
    bindings and the DP "PCS" region is really a set of DP_PHY registers.
    
    Add a new binding for the USB4-USB3-DP QMP PHYs found on SC8280XP which
    further bindings can be based on.
    
    Note that the binding uses a PHY index to access either the USB3 or DP
    part of the PHY and that this can later be used also for the USB4 part
    if needed.
    
    Similarly, the clock inputs and outputs can later be extended to support
    USB4.
    
    Also note that the current binding is simply removed instead of being
    deprecated as it was only recently merged and would not allow for
    supporting DP mode.
    Reviewed-by: default avatarRob Herring <robh@kernel.org>
    Signed-off-by: default avatarJohan Hovold <johan+linaro@kernel.org>
    Link: https://lore.kernel.org/r/20221121085058.31213-3-johan+linaro@kernel.orgSigned-off-by: default avatarVinod Koul <vkoul@kernel.org>
    e1c4c543
qcom,sc8280xp-qmp-usb43dp-phy.yaml 2 KB