49db3997d8
Suspending Goodix touchscreens requires changing the interrupt pin to output before sending them a power-down command. Followed by wiggling the interrupt pin to wake the device up, after which it is put back in input mode. So far we have only effectively supported this on devices which use devicetree. On X86 ACPI platforms both looking up the pins; and using a pin as both IRQ and GPIO is a bit more complicated. E.g. on some devices we cannot directly access the IRQ pin as GPIO and we need to call ACPI methods to control it instead. This commit adds a new irq_pin_access_method field to the goodix_chip_data struct and adds goodix_irq_direction_output and goodix_irq_direction_input helpers which together abstract the GPIO accesses to the IRQ pin. This is a preparation patch for adding support for properly suspending the touchscreen on X86 ACPI platforms. BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1786317 BugLink: https://github.com/nexus511/gpd-ubuntu-packages/issues/10 BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199207 Signed-off-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Bastien Nocera <hadess@hadess.net> Link: https://lore.kernel.org/r/20200307121505.3707-1-hdegoede@redhat.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.