drm/gma500: Refactor backlight support (v2)

Refactor backlight support so that the gma_backlight_enable() /
gma_backlight_disable() / gma_backlight_set() functions used by
the Opregion handle will also work if no backlight_device gets
registered.

This is a preparation patch for not registering the gma500's own backlight
device when acpi_video should be used, since registering 2 backlight
devices for a single display really is undesirable.

Since the acpi-video interface often uses the OpRegion we need to keep
the OpRegion functional even when dev_priv->backlight_device is NULL.

As a result of this refactor the actual backlight_device_register()
call is moved to the shared backlight.c code and all #ifdefs related to
CONFIG_BACKLIGHT_CLASS_DEVICE are now also limited to backlight.c .

No functional changes intended.

This has been tested on a Packard Bell Dot SC (Intel Atom N2600, cedarview)
and a Sony Vaio vpc-x11s1e (Intel N540, poulsbo) laptop.

Changes in v2:
- Fix unused variable warnings when CONFIG_BACKLIGHT is not selected by
marking the 2 variables as __maybe_unused.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220917205920.647212-2-hdegoede@redhat.com

drm/gma500: Cosmetic cleanup of irq code

Use the gma_ prefix instead of psb_ since the code is common for all
chips. Various coding style fixes. Removal of unused code. Removal of
duplicate function declarations.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220317092555.17882-4-patrik.r.jakobsson@gmail.com

drm/gma500: Embed struct drm_device in struct drm_psb_private

Embed struct drm_device in struct drm_psb_private. Replace the use
of dev_private by an upcast operation. Switch to managed release of
struct drm_psb_private.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210920141051.30988-4-tzimmermann@suse.de

drm/gma500: Replace references to dev_private with helper function

Replace most references to struct drm_device.dev_private with the new
helper function to_drm_psb_private(). The only references left are in
assignments and the helper itself.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210920141051.30988-2-tzimmermann@suse.de

drm/gma500: Remove references to struct drm_device.pdev

Using struct drm_device.pdev is deprecated. Convert gma500 to struct
drm_device.dev. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201201103542.2182-8-tzimmermann@suse.de

drm/gma500: remove unnecessary config_enabled() guard

Commit d112a8163f83 ("gma500/cdv: Add eDP support") replaced the
code inside this if-conditional with gma_backlight_set(), which
becomes a nop stub if CONFIG_BACKLIGHT_CLASS_DEVICE is disabled.
So, there is no need to guard the caller with config_enabled().

Note:
This is one of remaining TODOs to deprecate config_enabled() macro.
Refer to commit 97f2645f358b ("tree-wide: replace config_enabled()
with IS_ENABLED()").

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1471970574-23906-1-git-send-email-yamada.masahiro@socionext.com

drm/gma500: Move asle interrupt work into a work task

Previously the backlight code was called from IRQ context which isn't
allowed. This patch moves all the asle work into a work task which takes
care of the locking bug reported by users.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=64221
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>

ACPI / i915: Fix incorrect <acpi/acpi.h> inclusions via <linux/acpi_io.h>

To avoid build problems and breaking dependencies between ACPI header
files, <acpi/acpi.h> should not be included directly by code outside
of the ACPI core subsystem. However, that is possible if
<linux/acpi_io.h> is included, because that file contains
a direct inclusion of <acpi/acpi.h>.

For this reason, remove the direct <acpi/acpi.h> inclusion from
<linux/acpi_io.h>, move that file from include/linux/ to include/acpi/
and make <linux/acpi.h> include it for CONFIG_ACPI set along with the
other ACPI header files. Accordingly, Remove the inclusions of
<linux/acpi_io.h> from everywhere.

Of course, that causes the contents of the new <acpi/acpi_io.h> file
to be available for CONFIG_ACPI set only, so intel_opregion.o that
depends on it should also depend on CONFIG_ACPI (and it really should
not be compiled for CONFIG_ACPI unset anyway).

References: https://01.org/linuxgraphics/sites/default/files/documentation/acpi_igd_opregion_spec.pdf
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[rjw: Subject and changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

gma500/cdv: Add eDP support

Introduce the eDP support into the driver.

This has been reworked a bit because kernel driver proper uses encoder/connectors
while the legacy Intel driver uses the old output stuff.

It also diverges on the backlight handling. The legacy Intel driver adds a panel
abstraction based upon the i915 one. It's only really used for backlight bits
and we have a perfectly good backlight abstraction which can extend instead.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
[ported to upstream driver, redid backlight abstraction]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

gma500: move the ASLE enable

Otherwise we end up getting the masks wrong, can get events before we
are doing power control and other ungood things. Again this is a
regression fix where the ordering of handling was disturbed by other
work, and the user experience on some boxes is a blank screen.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gma500: silence an unused variable warning

If CONFIG_BACKLIGHT_CLASS_DEVICE is disabled then GCC warns that:
drivers/gpu/drm/gma500/opregion.c:154:6: warning:
unused variable ‘max’ [-Wunused-variable]

Which give me a chance to use the new config_enabled() macro. :)

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Paul Menzel <paulepanter@users.sourceforge.net>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

gma500: Fix build without ACPI

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

gma500: lid_state should be __iomem

This was mostly already fixed but this one change is needed to match Kirill's
original submission

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

gma500: opregion and ACPI

Add the opregion support and bring us in line with the opregion functionality in the
reference driver code. We can't share this with i915 currently because there are
hardcoded assumptions about dev_priv etc in both versions.

[airlied: include opregion.h fix]

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>