• Hans de Goede's avatar
    power: supply: axp288_charger: Use alt usb-id extcon on some x86 android tablets · ce38f3fc
    Hans de Goede authored
    x86 ACPI boards which ship with only Android as their factory image may
    have pretty broken ACPI tables. This includes broken _AEI ACPI GPIO event
    handlers, which are normally used to listen to the micro-USB ID pin and:
    
    1. Switch the USB-mux to the host / device USB controllers
    2. Disable Vbus path before enabling the 5V boost (AXP reg 0x30 bit 7)
    3. Turn 5V Vboost on / off
    
    On non broken systems where this is not done through an ACPI GPIO event
    handler, there is an ACPI INT3496 device describing the involved GPIOs
    which are handled by the extcon-intel-int3496 driver; and axp288-charger.ko
    listens to this extcon-device and disables the Vbus path when necessary.
    
    On x86 Android boards, with broken ACPI GPIO event handlers, these are
    disabled by acpi_quirk_skip_gpio_event_handlers() and an intel-int3496
    extcon device is manually instantiated by x86-android-tablets.ko .
    
    Add support to the axp288-charger code for this setup, so that it
    properly disables the Vbus path when necessary. Note this uses
    acpi_quirk_skip_gpio_event_handlers() to identify these systems,
    to avoid the need to add a separate DMI match table for this.
    Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
    Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
    ce38f3fc
axp288_charger.c 27.3 KB