• Hans de Goede's avatar
    Input: goodix - call acpi_device_fix_up_power() in some cases · 3de93e6e
    Hans de Goede authored
    On ACPI boards, when we cannot get the GPIOs to do a reset ourselves
    if necessary, call acpi_device_fix_up_power() to force the ACPI _PS0
    method to run.
    
    On some devices without proper GPIO descriptions this will reset
    the touchscreen for us and this may be necessary for us to be able
    to communicate to the touchscreen at all.
    
    Specifically on an Aya Neo Next this change will cause the _PS0()
    ACPI function to call INIT() which does:
    
                Method (INIT, 0, Serialized)
                {
                    TP_I = 0x00A50000
                    TP_R = 0x00A50000
                    Sleep (0x0A)
                    TP_I = 0x00E50000
                    Sleep (One)
                    TP_R = 0x00E50000
                    Sleep (0x06)
                    TP_I = 0x00A50000
                    Sleep (0x3C)
                    TP_I = 0x00041800
                }
    
    On older kernels the ACPI core assumed a power-on was necessary by itself
    and would run _PS0 before our probe function runs, which can be seen from
    the GPIO pin ctrl registers in /sys/kernel/debug/gpio which match
    the above hex values with older kernels.
    
    With newer kernels before this change the GPIO pin ctrl registers do not
    match, indicating INIT() has not run and probing the touchscreen fails.
    
    This change makes Linux run _PS0() again fixing the touchscreen not working
    on the Aya Neo Next.
    Reported-and-tested-by: default avatarMaya Matuszczyk <maccraft123mc@gmail.com>
    Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
    Link: https://lore.kernel.org/r/20220618210233.208027-1-hdegoede@redhat.comSigned-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
    3de93e6e
goodix.c 39.8 KB