On Sat, Jun 18, 2022 at 11:02:33PM +0200, Hans de Goede wrote:
> 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.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=209061
> Reported-and-tested-by: Maya Matuszczyk <maccraft123mc@xxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Applied, thank you.
--
Dmitry
