• Brian Norris's avatar
    arm64: dts: rockchip: move QCA6174A wakeup pin into its USB node · 5364a0b4
    Brian Norris authored
    Currently, we don't coordinate BT USB activity with our handling of the
    BT out-of-band wake pin, and instead just use gpio-keys. That causes
    problems because we have no way of distinguishing wake activity due to a
    BT device (e.g., mouse) vs. the BT controller (e.g., re-configuring wake
    mask before suspend). This can cause spurious wake events just because
    we, for instance, try to reconfigure the host controller's event mask
    before suspending.
    
    We can avoid these synchronization problems by handling the BT wake pin
    directly in the btusb driver -- for all activity up until BT controller
    suspend(), we simply listen to normal USB activity (e.g., to know the
    difference between device and host activity); once we're really ready to
    suspend the host controller, there should be no more host activity, and
    only *then* do we unmask the GPIO interrupt.
    
    This is already supported by btusb; we just need to describe the wake
    pin in the right node.
    
    We list 2 compatible properties, since both PID/VID pairs show up on
    Scarlet devices, and they're both essentially identical QCA6174A-based
    modules.
    
    Also note that the polarity was wrong before: Qualcomm implemented WAKE
    as active high, not active low. We only got away with this because
    gpio-keys always reconfigured us as bi-directional edge-triggered.
    
    Finally, we have an external pull-up and a level-shifter on this line
    (we didn't notice Qualcomm's polarity in the initial design), so we
    can't do pull-down. Switch to pull-none.
    Signed-off-by: default avatarBrian Norris <briannorris@chromium.org>
    Reviewed-by: default avatarMatthias Kaehlcke <mka@chromium.org>
    Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
    5364a0b4
rk3399-gru-scarlet.dtsi 12.2 KB