Since kernel 3.14 the backlight control has been broken on various Samsung
Atom based netbooks. This has been bisected and this problem happens since
commit b35684b8 ("drm/i915: do full backlight setup at enable time")

This has been reported and discussed in detail here:
http://lists.freedesktop.org/archives/intel-gfx/2014-July/049395.html

Unfortunately no-one has been able to fix this. This only affects Samsung
Atom netbooks, and the Linux kernel and the BIOS of those laptops have never
worked well together. All affected laptops already have a quirk to avoid using
the standard acpi-video interface and instead use the samsung specific SABI
interface which samsung-laptop uses. It seems that recent fixes to the i915
driver have also broken backlight control through the SABI interface.

The intel_backlight driver OTOH works fine, and also allows for finer grained
backlight control. So add a new use_native_backlight quirk, and replace the
broken_acpi_video quirk with this quirk for affected models. This new quirk
disables acpi-video as before and also stops samsung-laptop from registering
the SABI based samsung_laptop backlight interface, leaving only the working
intel_backlight interface.

This commit enables this new quirk for 3 models which are known to be affected,
chances are that it needs to be used on other models too.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1094948 # N145P
BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1115713 # N250P
Reported-by: Bertrik Sikken <bertrik@sikken.nl> # N150P
Cc: stable@vger.kernel.org # 3.16
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

The acpi-video backlight interface on the NC210 does not work, blacklist it
and use the samsung-laptop interface instead.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=861573
Cc: stable@vger.kernel.org
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>

These models have only 4 levels of keyboard backlight brightness and forget
how to work the backlight after resuming from S3 sleep. I've added a quirk
to set the appropriate number of backlight levels, and one to re-enable the
keyboard backlight on resume.

(Whitespace cleaned up by Matthew Garrett)
Signed-off-by: NScott Thrasher <scott.thrasher@gmail.com>
Signed-off-by: NMatthew Garrett <matthew.garrett@nebula.com>

It has been reported that running this driver on some Samsung laptops
with EFI can cause those machines to become bricked as detailed in the
following report,

	https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557

There have also been reports of this driver causing Machine Check
Exceptions on recent EFI-enabled Samsung laptops,

	https://bugzilla.kernel.org/show_bug.cgi?id=47121

So disable it if booting from EFI since this driver relies on
grovelling around in the BIOS memory map which isn't going to work.

Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

BugLink: http://bugs.launchpad.net/bugs/1086921
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NMatthew Garrett <matthew.garrett@nebula.com>

Signed-off-by: NCorentin Chary <corentin.chary@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

> Chassis Information
> 	Manufacturer: SAMSUNG ELECTRONICS CO., LTD.
>	Type: Other

Type should be "Notebook", "Laptop", .. not "Other".
Signed-off-by: NCorentin Chary <corentin.chary@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Signed-off-by: NCorentin Chary <corentin.chary@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Instead of using directly acpi_video_unregister(), use
acpi_video_dmi_promote_vendor() (and make it call
acpi_video_unregister() if needed)
Signed-off-by: NCorentin Chary <corentin.chary@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

On these laptops, the ACPI video is not functional, and very unlikely
to be fixed by the vendor. Note that intel_backlight works for some
of these laptops, and the backlight from samsung-laptop always work.

The good news is that newer laptops have functional ACPI video device
and won't end up growing this list.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

This function returns a umode_t (unsigned short) instead of mode_t which
is an unsigned int on some architectures.  Cleaning this up silences a
compile warning:

drivers/platform/x86/samsung-laptop.c:1108:2: warning: initialization
	from incompatible pointer type [enabled by default]
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

linux/ctype.h is needed for isalnum() to avoid a build error:

drivers/platform/x86/samsung-laptop.c: In function ‘samsung_sabi_diag’:
drivers/platform/x86/samsung-laptop.c:1306: error: implicit declaration of function ‘isalnum’
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Fields d0, d1, d2, and d3 are members of an anonymous struct inside an
anonymous union inside struct sabi_data.  Initialization must be done by
wrapping the anonymous union and structs with brackets to avoid a build
error:

drivers/platform/x86/samsung-laptop.c: In function ‘sabi_set_commandb’:
drivers/platform/x86/samsung-laptop.c:433: error: unknown field ‘d0’ specified in initializer
drivers/platform/x86/samsung-laptop.c:433: warning: missing braces around initializer
drivers/platform/x86/samsung-laptop.c:433: warning: (near initialization for ‘in.<anonymous>’)
...
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

- don't output error when probing features at load
- print the SABI signature if samsung_sabi_init()
  succeed
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

We still need to figure out exactly what each of different fields
represent, but they contain at least model and version informations.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

This enable the driver for everything that look like
a laptop and is from vendor "SAMSUNG ELECTRONICS CO., LTD.".
Note that laptop supported by samsung-q10 seem to have a different
vendor strict.

Also remove every log output until we know that we have a SABI interface
(except if the driver is forced to load, or debug is enabled).

Keeping a whitelist of laptop with a model granularity is something that can't
work without close vendor cooperation (and we don't have that).
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

The wireless status get and get commands seems to use one
byte per device. First byte is for wlan and third is for bluetooh,
we will have to find what the other are for.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

We can now do the self test using debugfs, so remove the code
and keep the debug flag to enable more traces.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

This allow to call arbitrary sabi commands wihout
modifying the driver at all. For example, setting
the keyboard backlight brightness to 5 using debugfs
interface can be done like that:

 ; Set the command
 echo 0x78 > command
 ; Set the data
 echo 0x0582 > d0
 ; Fill the rest with 0
 echo 0 > d1
 echo 0 > d2
 echo 0 > d3
 ; And issue the command
 cat call
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

* SABI command are on 16 bits, not 8
* SABI can read/write up to 11 byte of data
* There is not real difference between "get" and "set"
  commands, so refactorise the code of both functions
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Will be usefull later when we will have more platform sysfs files
like battery_life_extender or usb_charge.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

samsung-laptop is not at all related to ACPI, but since this interface
is not documented at all, and the driver has to use it at load to
understand how it works on the laptop, I think it's a good idea to
disable it if a better solution is available.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Create _init()/_exit() function for each subsystem, remove
the local struct samsung_laptop * and only keep a
struct platform_device * that can only be used in samsung_init()
and samsung_exit().
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Even if this driver can only be loaded once, it is still a good
idea to create some kind of context structure.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option.  For this version
it'll simply give a warning, but it'll break next kernel version.
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

my samsung laptop would be very happy if you add
these lines to the file drivers/platform/x86/samsung-laptop.c

Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

My DMI model is this:
>dmesg |grep DMI
[    0.000000] DMI present.
[    0.000000] DMI: SAMSUNG ELECTRONICS CO., LTD. SR700/SR700, BIOS
04SR 02/20/2008

adding dmi information of Samsung R700 laptops
This adds the dmi information of Samsungs R700 laptops.
Signed-off-by: NStefan Beller <stefanbeller@googlemail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

This patch depends on the "Platform: Brightness quirk for samsung
laptop driver" patch from Jason Stubbs. This patch adds a check for an
initial brightness level of 0; if the level is 0, this patch changes
the brightness level to 1 before the driver attempts to detect the
brightness quirk.

The Samsung N150 netbook experiences the brightness quirk. Without
Jason's patch, the only brightness levels available on the N150 are 0,
1, and 8. This patch ensures that, when the initial brightness level
is 0, the samsang-laptop driver detects the brightness quirk on the
N150, thereby making brightness levels 0 through 8 available.
Signed-off-by: NJohn Serock <john.serock@gmail.com>
Acked-by: NJason Stubbs <jasonbstubbs@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

This is a follow-up for commit 78a7539b, which didn't cover the
Samsung N220 laptop. With this backlight brightness works nicely
on the N220 netbook.
Signed-off-by: NRaul Gutierrez Segales <rgs@collabora.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

This patch just adds the DMI info for the samsung laptop driver to work with
the NC210/NC110. It needs the brightness quirk patch for proper support.
Signed-off-by: NJason Stubbs <jasonbstubbs@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

On some Samsung laptops the brightness regulation works slightly different.
All SABI commands except for set_brightness work as expected. The behaviour
of set_brightness is as follows:

- Setting a new brightness will only step one level toward the new brightness
  level. For example, setting a level of 5 when the current level is 2 will
  result in a brightness level of 3.
- A spurious KEY_BRIGHTNESS_UP or KEY_BRIGHTNESS_DOWN event is also generated
  along with the change in brightness.
- Neither of the above two issues occur when changing from/to brightness
  level 0.

This patch adds detection and a non-intrusive workaround for the above issues.
Signed-off-by: NJason Stubbs <jasonbstubbs@gmail.com>
Tested-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

samsung_init() should not return success if not all devices are initialized.
Otherwise, samsung_exit() will dereference sdev NULL pointers and others.
Signed-off-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

The min_brightness value of the sabi_config is incorrectly used in brightness
calculations. For the config where min_brightness = 1 and max_brightness = 8,
the user visible range should be 0 to 7 with hardware being set in the range
of 1 to 8. What is actually happening is that the user visible range is 0 to
8 with hardware being set in the range of -1 to 7.

This patch fixes the above issue as well as a miscalculation that would occur
in the case of min_brightness > 1.
Signed-off-by: NJason Stubbs <jasonbstubbs@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

patch works for me, but I need to add "acpi_backlight=vendor" to kernel
params
Signed-off-by: NSmelov Andrey <xor29a@bk.ru>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

Some samsung latop of the N150/N2{10,20,30} serie are badly detected by the samsung-laptop platform driver, see bug # 36082.
It appears that N230 identifies itself as N150/N210/N220/N230 whereas the other identify themselves as N150/N210/220.
This patch attemtp fix #36082 allowing correct identification for all the said netbook model.
Reported-by: NDaniel Eklöf <daniel@ekloef.se>
Signed-off-by: NThomas Courbon <thcourbon@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

The N510 benefits from this code as well. Below is a patch to include support.
Signed-off-by: NJouke Witteveen <j.witteveen@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>