If an ACPI graphics device supports backlight brightness functions (cmp. with
latest ACPI spec Appendix B), let the ACPI video driver control backlight and
switch backlight control off in vendor specific ACPI drivers (asus_acpi,
thinkpad_acpi, eeepc, fujitsu_laptop, msi_laptop, sony_laptop, acer-wmi).

Currently it is possible to load above drivers and let both poke on the
brightness HW registers, the video and vendor specific ACPI drivers -> bad.

This patch provides the basic support to check for BIOS capabilities before
driver loading time. Driver specific modifications are in separate follow up
patches.

"acpi_backlight=vendor"
	Prever vendor driver over ACPI driver for backlight.
"acpi_backlight=video" (default)
	Prever ACPI driver over vendor driver for backlight.
Signed-off-by: NThomas Renninger <trenn@suse.de>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

This is a reimplemention of commit
0119509c
from Matthew Garrett <mjg59@srcf.ucam.org>

This patch got removed because of a regression: ThinkPads with a
Intel graphics card and an Integrated Graphics Device BIOS implementation
stopped working.
In fact, they only worked because the ACPI device of the discrete, the
wrong one, got used (via int10). So ACPI functions were poking on the wrong
hardware used which is a sever bug.
The next patch provides support for above ThinkPads to be able to
switch brightness via the legacy thinkpad_acpi driver and automatically
detect when to use it.

Original commit message from Matthew Garrett:
    Vendors often ship machines with a choice of integrated or discrete
    graphics, and use the same DSDT for both. As a result, the ACPI video
    module will locate devices that may not exist on this specific platform.
    Attempt to determine whether the device exists or not, and abort the
    device creation if it doesn't.

http://bugzilla.kernel.org/show_bug.cgi?id=9614Signed-off-by: NThomas Renninger <trenn@suse.de>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Move all the component definitions for drivers to a single shared place,
include/acpi/acpi_drivers.h.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

I don't think there's any point in cluttering the code with these.
Better to improve the documentation so *anybody* can figure out
what layer & level to use.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

ACPI_DB_ERROR and ACPI_DB_WARN were removed from ACPICA core.
So replace ACPI_DEBUG_PRINT((ACPI_DB_ERROR, ...) with printk(KERN_ERR PREFIX ...)
and ACPI_DEBUG_PRINT((ACPI_DB_WARN, ...) with printk(KERN_WARNING PREFIX ...)

We do not use ACPI_ERROR/ACPI_WARNING since they're not exported, see
-------------------------------------------------------------
commit 6468463a
Author: Len Brown <len.brown@intel.com>
Date:   Mon Jun 26 23:41:38 2006 -0400

    ACPI: un-export ACPI_ERROR() -- use printk(KERN_ERR...)
Signed-off-by: NLen Brown <len.brown@intel.com>
-------------------------------------------------------------
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

As of version 2.0, ACPI can return 64-bit integers.  The current
acpi_evaluate_integer only supports 64-bit integers on 64-bit platforms.
Change the argument to take a pointer to an acpi_integer so we support
64-bit integers on all platforms.

lenb: replaced use of "acpi_integer" with "unsigned long long"
lenb: fixed bug in acpi_thermal_trips_update()
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Catch attempts to use of acpi_driver_data on pointers of wrong type.

akpm: rewritten to use proper C typechecking and remove the
"function"-used-as-lvalue thing.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

We have the dev_printk() variants for this kind of thing, use them
instead of directly trying to access the bus_id field of struct device.

This is done in order to remove bus_id entirely.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

According to acpi spec , the objectes of  _BCL and _BCM are required if
integrated LCD is present and supports brightness level and the _BQC is
the optional object. So the _BQC object will be ignored when the backlight
device is registered.
At the same time when there is no _BQC object, the current brightness will be
set to the maximum.

http://bugzilla.kernel.org/show_bug.cgi?id=10206Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NZhang Rui  <rui.zhang@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>

Fix use of uninitialized device->brightness.
Signed-off-by: NJulia Jomantaite <julia.jomantaite@gmail.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The child of a video bus device is not alway a video device.
It should be a warn message rather than an exception here.
http://bugzilla.kernel.org/show_bug.cgi?id=9761Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

acpi_device_dir() is NULL until all files are createst, so everyting is
created in straight in /proc/ and creation code warns.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data
be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

POST and DOS are supposed to be writable but permissions
did not allow it.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Have acpi_video_device_add_fs() and acpi_video_bus_add_fs()
properly unwind proc creation after error.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

this is a cleanup, not a change to function.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

thermal_cooling_device_register used to return NULL if THERMAL is "n".
As the ACPI fan, processor and video drivers SELECT the generic
thermal in PATCH 01, this is not a problem any more.
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

This reverts commit 7c0ea45b which
caused a regression with the backlight being set to off when a laptop
doesn't have a _BQC entry to query the actual backlight value.  The code
blindly then falls back on a value of 0.

See
	http://bugzilla.kernel.org/show_bug.cgi?id=10387
	http://lkml.org/lkml/2008/4/2/366

for details.
Bisected-and-reported-by: NAndrey Borzenkov <arvidjaar@mail.ru>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert commit 1192aeb9 ("ACPI:
drivers/acpi: elide a non-zero test on a result that is never 0")
because it turns out that thermal_cooling_device_register() does
actually return NULL if CONFIG_THERMAL is turned off (then the routine
turns into a dummy inline routine in the header files that returns NULL
unconditionally).

This was found with randconfig testing, causing a crash during bootup:

  initcall 0x78878534 ran for 13 msecs: acpi_button_init+0x0/0x51()
  Calling initcall 0x78878585: acpi_fan_init+0x0/0x2c()
  BUG: unable to handle kernel NULL pointer dereference at 00000000
  IP: [<782b8ad0>] acpi_fan_add+0x7d/0xfd
  *pde = 00000000
  Oops: 0000 [#1]
  Modules linked in:

  Pid: 1, comm: swapper Not tainted (2.6.25-rc7-sched-devel.git-x86-latest.git #14)
  EIP: 0060:[<782b8ad0>] EFLAGS: 00010246 CPU: 0
  EIP is at acpi_fan_add+0x7d/0xfd
  EAX: b787c718 EBX: b787c400 ECX: b782ceb4 EDX: 00000007
  ESI: 00000000 EDI: b787c6f4 EBP: b782cee0 ESP: b782cecc
   DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
  Process swapper (pid: 1, ti=b782c000 task=b7846000 task.ti=b782c000)
  Stack: b787c459 00000000 b787c400 78790888 b787c60c b782cef8 782b6fb8 ffffffda
         b787c60c 00000000 78790958 b782cf0c 783005d7 b787c60c 78790958 78790584
         b782cf1c 783007f6 b782cf28 00000000 b782cf40 782ffc4a 78790958 b794d558
  Call Trace:
   [<782b6fb8>] ? acpi_device_probe+0x3e/0xdb
   [<783005d7>] ? driver_probe_device+0x82/0xfc
   [<783007f6>] ? __driver_attach+0x3a/0x70
   [<782ffc4a>] ? bus_for_each_dev+0x3e/0x60
   [<7830048c>] ? driver_attach+0x14/0x16
   [<783007bc>] ? __driver_attach+0x0/0x70
   [<7830006a>] ? bus_add_driver+0x9d/0x1b0
   [<783008c3>] ? driver_register+0x47/0xa3
   [<7813db00>] ? timespec_to_ktime+0x9/0xc
   [<782b7331>] ? acpi_bus_register_driver+0x3a/0x3c
   [<78878592>] ? acpi_fan_init+0xd/0x2c
   [<78863656>] ? kernel_init+0xac/0x1f9
   [<788635aa>] ? kernel_init+0x0/0x1f9
   [<78114563>] ? kernel_thread_helper+0x7/0x10
   =======================
  Code: 6e 78 e8 57 44 e7 ff 58 e9 93 00 00 00 8b 55 f0 8d bb f4 02 00 00 80 4b 2d 10 8b 03 e8 87 cb ff ff 8d 83 18 03 00 00 80 63 2d ef <ff> 35 00 00 00 00 50 68 e8 9c 6e 78 e8 22 44 e7 ff b9 b6 9c 6e
  EIP: [<782b8ad0>] acpi_fan_add+0x7d/0xfd SS:ESP 0068:b782cecc
  ---[ end trace 778e504de7e3b1e3 ]---
  Kernel panic - not syncing: Attempted to kill init!
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The function thermal_cooling_device_register always returns either a valid
pointer or a value made with ERR_PTR, so a test for non-zero on the result
will always succeed.

The problem was found using the following semantic match.
(http://www.emn.fr/x-info/coccinelle/)

//<smpl>
@a@
expression E, E1;
statement S,S1;
position p;
@@

E = thermal_cooling_device_register(...)
... when != E = E1
if@p (E) S else S1

@n@
position a.p;
expression E,E1;
statement S,S1;
@@

E = NULL
... when != E = E1
if@p (E) S else S1

@depends on !n@
expression E;
statement S,S1;
position a.p;
@@

* if@p (E)
  S else S1
//</smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

This reverts commit 0119509c.

http://bugzilla.kernel.org/show_bug.cgi?id=9995Signed-off-by: NLen Brown <len.brown@intel.com>

This reverts commit 3fa2cdcc.

http://bugzilla.kernel.org/show_bug.cgi?id=9995

Signed-off-by: Len Brown <len.brown>

According to acpi spec , the objects of  _BCL and _BCM are required if
integrated LCD is present and supports brightness level .The _BQC is
the optional object. So the _BQC object is ignored when the backlight device
is registered in ACPI video driver.

http://bugzilla.kernel.org/show_bug.cgi?id=10206Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NZhang Rui  <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Need to check whether thermal_cooling_device_register
returned ERROR or not.
Signed-off-by: NThomas Sujith <sujith.thomas@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Vendors often ship machines with a choice of integrated or discrete
graphics, and use the same DSDT for both. As a result, the ACPI video
module will locate devices that may not exist on this specific platform.

Attempt to determine whether the device exists or not, and abort the
device creation if it do not exist.
Signed-off-by: NMatthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some machines seem to need the backlight brightness to be reset on resume.
Add support for doing so to the video module.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NMatthew Garrett <mjg59@srcf.ucam.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>

Call notifier chain for display/brightness switch events.
The kernel mode graphics driver is interested in this.
Sign-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Display switching via ACPI control methods are
not known to work on any platforms.

Further, the X community wants to control the display
switching all by themselves without BIOS/AML involvement.
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Introduce new module parameter for brightness control.
"brightness_switch_enabled" is set by default which means
nothing changes upon brightness switch events.

When "brightness_switch_enabled" is cleared via
"echo 0 > /sys/module/video/parameters/brightness_switch_enabled",
ACPI will not try to change the brightness level any more.

Either X will take charge of this or users can change the brightness level
by poking /sys/class/backlight/acpi_videoX/...
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Vendors often ship machines with a choice of integrated or discrete
graphics, and use the same DSDT for both. As a result, the ACPI video
module will locate devices that may not exist on this specific platform.
Attempt to determine whether the device exists or not, and abort the
device creation if it doesn't.

http://bugzilla.kernel.org/show_bug.cgi?id=9614Signed-off-by: NMatthew Garrett <mjg59@srcf.ucam.org>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Register ACPI video device as thermal cooling devices as they may be listed
in _TZD method and the backlight control can be used for throttling.
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NThomas Sujith <sujith.thomas@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The sysfs backlight class provides no mechanism for querying the
acceptable brightness for a backlight. The ACPI spec states that values
are only valid if they are reported as available by the firmware. Since
we can't provide that information to userspace, instead collapse the
range to the number of actual values that can be set.

http://bugzilla.kernel.org/show_bug.cgi?id=9277Signed-off-by: NMatthew Garrett <mjg59@srcf.ucam.org>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The ->cap fields of struct acpi_video_device and struct acpi_video_bus
are 1B each, not 4B. The oversized memset()'s corrupted the subsequent
list_head fields. This resulted in silent corruption without
CONFIG_DEBUG_LIST and BUG's with it. This patch uses sizeof() to pass
the proper bounds to the memset() calls and thereby correct the bugs.
Signed-off-by: NWilliam Irwin <wli@holomorphy.com>
Acked-by: NMikael Pettersson <mikpe@it.uu.se>
Signed-off-by: NLen Brown <len.brown@intel.com>

In order to be able to write the value "100"
to /proc/acpi/video/.../brightness, we have to allocate 5 bytes:
4 characters will be written (1, 0, 0 plus null byte),
and 1 byte should be buffer for a terminating NULL character.

http://bugzilla.kernel.org/show_bug.cgi?id=9278Signed-off-by: NDanny Baumann <dannybaumann@web.de>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

printk("video bus notify\n");
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

list_for_each_safe() only protects list from list alterations
performed by the same thread. One still needs to implement
proper locking when list is being accessed from several threads.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

If input_register_device() fails input_free_device() must
be called to release memory allocated for the device.
Also consolidate error handling in acpi_bus_video_add()
and handle input_allocate_device() failures.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Properly set up parent on input device registered by the video driver.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>