backlight: apple_bl: Use acpi_video_get_backlight_type()

On some MacBooks both the apple_bl and the apple-gmux backlight drivers
may be able to export a /sys/class/backlight device.

To avoid having 2 backlight devices for one LCD panel until now
the apple-gmux driver has been calling apple_bl_unregister() to move
the apple_bl backlight device out of the way when it loads.

Similar problems exist on other x86 laptops and all backlight drivers
which may be used on x86 laptops have moved to using
acpi_video_get_backlight_type() to determine whether they should load
or not.

Switch apple_bl to this model too, so that it is consistent with all
the other x86 backlight drivers.

Besides code-simplification and consistency this has 2 other benefits:

1) It removes a race during boot where userspace will briefly see
an apple_bl backlight and then have it disappear again, leading to e.g.:
https://bbs.archlinux.org/viewtopic.php?id=269920

2) This allows user to switch between the drivers by passing
acpi_backlight=apple_gmux or acpi_backlight=vendor on the kernel
commandline.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230307120540.389920-1-hdegoede@redhat.com

ACPI: make remove callback of ACPI driver void

For bus-based driver, device removal is implemented as:
1 device_remove()->
2 bus->remove()->
3 driver->remove()

Driver core needs no inform from callee(bus driver) about the
result of remove callback. In that case, commit fc7a6209d571
("bus: Make remove callback return void") forces bus_type::remove
be void-returned.

Now we have the situation that both 1 & 2 of calling chain are
void-returned, so it does not make much sense for 3(driver->remove)
to return non-void to its caller.

So the basic idea behind this change is making remove() callback of
any bus-based driver to be void-returned.

This change, for itself, is for device drivers based on acpi-bus.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Lee Jones <lee@kernel.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dawei Li <set_pte_at@outlook.com>
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for drivers/platform/surface/*
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

backlight: apple_bl: Deprecate pci_get_bus_and_slot()

pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
where a PCI device is present. This restricts the device drivers to be
reused for other domain numbers.

Getting ready to remove pci_get_bus_and_slot() function in favor of
pci_get_domain_bus_and_slot().

Hard-coding the domain as 0.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

ACPI: Remove useless type argument of driver .remove() operation

The second argument of ACPI driver .remove() operation is only used
by the ACPI processor driver and the value passed to that driver
through it is always available from the given struct acpi_device
object's removal_type field. For this reason, the second ACPI driver
.remove() argument is in fact useless, so drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>

backlight: remove use of __devexit

CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

backlight: remove use of __devinit

CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

backlight: apple_bl: use pr_debug()/pr_err() instead of printk()

Use pr_debug()/pr_err() instead of printk() to allow dynamic debugging.
The pr_fmt prefix for pr_ macros is used. Also fix checkpatch warnings as
below:

WARNING: Prefer pr_debug(... to printk(KERN_DEBUG, ...
WARNING: Prefer pr_err(... to printk(KERN_ERR, ...

[akpm@linux-foundation.org: use KBUILD_MODNAME, per Joe]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/apple_bl.c: include header for exported symbol prototypes

Include the header to pickup the exported symbol prototype.

Quiets the sparse warning:

warning: symbol 'apple_bl_register' was not declared. Should it be static?
warning: symbol 'apple_bl_unregister' was not declared. Should it be static?

[akpm@linux-foundation.org: fix resulting build error]
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

apple_bl: Add register/unregister functions

Add functions to allow other modules to enable or disable apple_bl. This
will be used by the gmux driver to disable apple_bl when the gmux is
present, as it is a better and more reliable option for brightness
control.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

mbp_nvidia_bl: rename to apple_bl

It works on hardware other than Macbook Pros, and it works on GPUs other
than Nvidia. It should even work on iMacs, so change the name to match
reality more precisely and include an alias so existing users don't get
confused.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Mourad De Clerck <mourad@aquazul.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>