diff mbox series

[v7] platform/x86: samsung-galaxybook: Add samsung-galaxybook driver

Message ID 20250118004322.10062-1-josh@joshuagrisham.com (mailing list archive)
State New
Headers show
Series [v7] platform/x86: samsung-galaxybook: Add samsung-galaxybook driver | expand

Commit Message

Joshua Grisham Jan. 18, 2025, 12:43 a.m. UTC
Add a new driver for Samsung Galaxy Book series notebook devices with the
following features:

- Keyboard backlight control
- Battery extension with charge control end threshold
- Controller for Samsung's performance modes using the platform profile
  interface
- Adds firmware-attributes to control various system features
- Handles various hotkeys and notifications

Signed-off-by: Joshua Grisham <josh@joshuagrisham.com>

---

v1->v2:
- Attempt to resolve all review comments from v1 as written here:
https://lore.kernel.org/platform-driver-x86/53c5075b-1967-45d0-937f-463912dd966d@gmx.de/T/#mbcbd8d5d9bc4496bac5486636c7d3b32bc3e5cd0

v2->v3:
- Tweak to battery attribute to closer match pattern in dell-wmi-ddv
- implement platform_profile_remove() change from
  9b3bb37b44a317626464e79da8b39989b421963f
- Small tweak to Documentation page

v3->v4:
- Remove custom tracepoint (can trace via existing mechanisms)
- Remove module parameters
- Move sysfs attributes from device to firmware-attributes
- Refactor "allow_recording" to "camera_lens_cover" plus other small
  renames in aim to have more standardized naming that are cross-vendor
- Attempt to improve locking mechanisms
- Tweak logic for setting and getting led brightness
- More fixes for aiming to use devres/devm pattern
- Change battery charge end threshold to use 1 to 100 instead of 0 to 99
- Add swtich input event for camera_lens_cover remove all others (they will
  be generated as ACPI netlink events instead)
- Various other small tweaks and features as requested from feedback

v4-v5:
- Prefix all locally defined symbols with "GB_" as a namespace
- Remove extra unused out_buf from galaxybook_acpi_method
- Tighten up logic flow for setting and unsetting global pointer (now it
  is done directly in association with the i8042 filter init and exit)
- Rename "camera_lens_cover" to "block_recording"
- Change input device to only apply for "Camera Lens Cover", remove sparse
  keymap and set capabilities manually as part of block_recording init,
  then notify using input_report_switch when setting block_recording
- Correct firmware-attributes enumeration implementation (adding all
  attributes) and remove erroneous ABI fw attrs docs update
- Few small tweaks to how locks are used
- Use device_unregister instead of device_destroy for firmware attributes
  device
- Tighten up and clean up performance mode to profile mapping logic; now
  the mapping is largely "fixed" apart from "Ultra" that will map to
  performance while also re-mapping "Performance" to balanced-performance
- Tighten up error handling so probe will fail in more cases where it
  should fail
- Replace platform_profile_register with devm_platform_profile_register

v5->v6:
- A few small clean-up/fixes as requested from feedback
- Revamp performance mode profile mapping so it is more static and relies
  more on the facilities already built in to platform_profile, including:
  - setting and using bits on profile handler choices to drive most of the
    behavior instead of having totally separate logic
  - get_performance_mode_profile() is now a mostly static mapping that
    drives both setting initial profile choices and retrieving the right
    profile for a given performance_mode during runtime
  - during init most of the mappings are hard-coded and the only things
    that are changed are the exception cases (override legacy values and
    downgrade of performance when Ultra mode is present)
  - new function galaxybook_performance_mode_init() now handles initial
    startup performance mode in a much more simple and straight-forward way

v6->v7:
- Rebase to latest for-next and implement updates to firmware-attributes,
  platform_profile, and i8042 filter (including removal of global pointer).
---
 Documentation/admin-guide/laptops/index.rst   |    1 +
 .../laptops/samsung-galaxybook.rst            |  170 ++
 MAINTAINERS                                   |    7 +
 drivers/platform/x86/Kconfig                  |   17 +
 drivers/platform/x86/Makefile                 |    5 +-
 drivers/platform/x86/samsung-galaxybook.c     | 1506 +++++++++++++++++
 6 files changed, 1704 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/admin-guide/laptops/samsung-galaxybook.rst
 create mode 100644 drivers/platform/x86/samsung-galaxybook.c

Comments

Kurt Borja Jan. 18, 2025, 7:04 a.m. UTC | #1
Hi Joshua,

I have some comments on the platform profile section. The most important
one is the platform_profile probe one, the rest are suggetions.

On Fri Jan 17, 2025 at 7:43 PM -05, Joshua Grisham wrote:
> Add a new driver for Samsung Galaxy Book series notebook devices with the
> following features:
>
> - Keyboard backlight control
> - Battery extension with charge control end threshold
> - Controller for Samsung's performance modes using the platform profile
>   interface
> - Adds firmware-attributes to control various system features
> - Handles various hotkeys and notifications
>
> Signed-off-by: Joshua Grisham <josh@joshuagrisham.com>

...

> +/*
> + * Platform Profile / Performance mode
> + */
> +
> +static int performance_mode_acpi_set(struct samsung_galaxybook *galaxybook,
> +				     const u8 performance_mode)
> +{
> +	struct sawb buf = {};
> +
> +	buf.safn = GB_SAFN;
> +	buf.sasb = GB_SASB_PERFORMANCE_MODE;
> +	export_guid(buf.caid, &GB_PERFORMANCE_MODE_GUID);
> +	buf.fncn = GB_FNCN_PERFORMANCE_MODE;
> +	buf.subn = GB_SUBN_PERFORMANCE_MODE_SET;
> +	buf.iob0 = performance_mode;
> +
> +	return galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_PERFORMANCE_MODE,
> +				      &buf, GB_SAWB_LEN_PERFORMANCE_MODE);
> +}
> +
> +static int performance_mode_acpi_get(struct samsung_galaxybook *galaxybook, u8 *performance_mode)
> +{
> +	struct sawb buf = {};
> +	int err;
> +
> +	buf.safn = GB_SAFN;
> +	buf.sasb = GB_SASB_PERFORMANCE_MODE;
> +	export_guid(buf.caid, &GB_PERFORMANCE_MODE_GUID);
> +	buf.fncn = GB_FNCN_PERFORMANCE_MODE;
> +	buf.subn = GB_SUBN_PERFORMANCE_MODE_GET;
> +
> +	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_PERFORMANCE_MODE,
> +				     &buf, GB_SAWB_LEN_PERFORMANCE_MODE);
> +	if (err)
> +		return err;
> +
> +	*performance_mode = buf.iob0;
> +
> +	return 0;
> +}
> +
> +static int get_performance_mode_profile(struct samsung_galaxybook *galaxybook,
> +					const u8 performance_mode,
> +					enum platform_profile_option *profile)
> +{
> +	switch (performance_mode) {
> +	case GB_PERFORMANCE_MODE_SILENT:
> +		*profile = PLATFORM_PROFILE_LOW_POWER;
> +		break;
> +	case GB_PERFORMANCE_MODE_QUIET:
> +		*profile = PLATFORM_PROFILE_QUIET;
> +		break;
> +	case GB_PERFORMANCE_MODE_OPTIMIZED:
> +	case GB_PERFORMANCE_MODE_OPTIMIZED_LEGACY:
> +		*profile = PLATFORM_PROFILE_BALANCED;
> +		break;
> +	case GB_PERFORMANCE_MODE_PERFORMANCE:
> +	case GB_PERFORMANCE_MODE_PERFORMANCE_LEGACY:
> +		/* balanced-performance maps to Performance when Ultra exists */
> +		if (test_bit(PLATFORM_PROFILE_BALANCED_PERFORMANCE,
> +			     galaxybook->platform_profile_choices))
> +			*profile = PLATFORM_PROFILE_BALANCED_PERFORMANCE;
> +		else
> +			*profile = PLATFORM_PROFILE_PERFORMANCE;
> +		break;
> +	case GB_PERFORMANCE_MODE_ULTRA:
> +		*profile = PLATFORM_PROFILE_PERFORMANCE;
> +		break;
> +	case GB_PERFORMANCE_MODE_IGNORE1:
> +	case GB_PERFORMANCE_MODE_IGNORE2:
> +		return -EOPNOTSUPP;
> +	default:
> +		dev_warn(&galaxybook->platform->dev,
> +			 "unrecognized performance mode 0x%x\n", performance_mode);
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int galaxybook_platform_profile_set(struct device *dev,
> +					   enum platform_profile_option profile)
> +{
> +	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
> +
> +	return performance_mode_acpi_set(galaxybook,
> +					 galaxybook->profile_performance_modes[profile]);
> +}
> +
> +static int galaxybook_platform_profile_get(struct device *dev,
> +					   enum platform_profile_option *profile)
> +{
> +	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
> +	u8 performance_mode;
> +	int err;
> +
> +	err = performance_mode_acpi_get(galaxybook, &performance_mode);
> +	if (err)
> +		return err;
> +
> +	return get_performance_mode_profile(galaxybook, performance_mode, profile);
> +}
> +
> +static int galaxybook_platform_profile_probe(void *drvdata, unsigned long *choices)
> +{
> +	struct samsung_galaxybook *galaxybook = drvdata;
> +	int i;
> +
> +	for_each_set_bit(i, galaxybook->platform_profile_choices, PLATFORM_PROFILE_LAST)
> +		set_bit(i, choices);

The intended use of this callback is to "probe" for available choices
here. You should move all galaxybook_performance_mode_profile_init()
logic to this method. This would eliminate the need to have a copy of
the choices bitmap.

> +
> +	return 0;
> +}
> +
> +static const struct platform_profile_ops galaxybook_platform_profile_ops = {
> +	.probe = galaxybook_platform_profile_probe,
> +	.profile_get = galaxybook_platform_profile_get,
> +	.profile_set = galaxybook_platform_profile_set,
> +};
> +
> +static int galaxybook_performance_mode_init(struct samsung_galaxybook *galaxybook)
> +{
> +	enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
> +	u8 performance_mode;
> +	int err;
> +	int i;
> +
> +	err = performance_mode_acpi_get(galaxybook, &performance_mode);
> +	if (err)
> +		return err;
> +
> +	err = get_performance_mode_profile(galaxybook, performance_mode, &profile);
> +	if (err)

If this method failed we can't safely continue. I think you should
return here, else you may get an out of bounds access bellow.

> +		dev_warn(&galaxybook->platform->dev,
> +			 "initial startup performance mode 0x%x is not mapped\n",
> +			 performance_mode);
> +
> +	for_each_set_bit(i, galaxybook->platform_profile_choices, PLATFORM_PROFILE_LAST)
> +		dev_dbg(&galaxybook->platform->dev,
> +			"enabled platform profile %d using performance mode 0x%x\n",
> +			i, galaxybook->profile_performance_modes[i]);

Maybe we can log this directly in the switch-case block inside
galaxybook_performance_mode_profile_init() instead of having to iterate.

> +
> +	/* ensure startup performance_mode matches that mapped to its profile */
> +	if (galaxybook->profile_performance_modes[profile] == performance_mode)
> +		return 0;
> +
> +	/* otherwise, if balanced is enabled, use it as the default */
> +	if (test_bit(PLATFORM_PROFILE_BALANCED, galaxybook->platform_profile_choices))
> +		return performance_mode_acpi_set(galaxybook,
> +			galaxybook->profile_performance_modes[PLATFORM_PROFILE_BALANCED]);
> +
> +	/* otherwise, find the first enabled profile and use that instead */
> +	profile = find_next_bit_wrap(galaxybook->platform_profile_choices,
> +				     PLATFORM_PROFILE_LAST,
> +				     0);
> +
> +	if (profile == PLATFORM_PROFILE_LAST) {
> +		dev_err(&galaxybook->platform->dev,
> +			"no platform profiles have been enabled\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return performance_mode_acpi_set(galaxybook,
> +					 galaxybook->profile_performance_modes[profile]);
> +}
> +
> +#define gb_pfmode(profile) galaxybook->profile_performance_modes[profile]
> +
> +static int galaxybook_performance_mode_profile_init(struct samsung_galaxybook *galaxybook)
> +{
> +	enum platform_profile_option profile;
> +	struct sawb buf = {};
> +	unsigned int i;
> +	int err;
> +
> +	/* fetch supported performance mode values from ACPI method */
> +	buf.safn = GB_SAFN;
> +	buf.sasb = GB_SASB_PERFORMANCE_MODE;
> +	export_guid(buf.caid, &GB_PERFORMANCE_MODE_GUID);
> +	buf.fncn = GB_FNCN_PERFORMANCE_MODE;
> +	buf.subn = GB_SUBN_PERFORMANCE_MODE_LIST;
> +
> +	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_PERFORMANCE_MODE,
> +				     &buf, GB_SAWB_LEN_PERFORMANCE_MODE);
> +	if (err) {
> +		dev_dbg(&galaxybook->platform->dev,
> +			"failed to get supported performance modes, error %d\n", err);
> +		return err;
> +	}
> +
> +	/* set initial default profile performance mode mappings */
> +	gb_pfmode(PLATFORM_PROFILE_LOW_POWER) = GB_PERFORMANCE_MODE_SILENT;
> +	gb_pfmode(PLATFORM_PROFILE_QUIET) = GB_PERFORMANCE_MODE_QUIET;
> +	gb_pfmode(PLATFORM_PROFILE_BALANCED) = GB_PERFORMANCE_MODE_OPTIMIZED_LEGACY;
> +	gb_pfmode(PLATFORM_PROFILE_PERFORMANCE) = GB_PERFORMANCE_MODE_PERFORMANCE_LEGACY;
> +	gb_pfmode(PLATFORM_PROFILE_LAST) = GB_PERFORMANCE_MODE_INVALID;
> +
> +	/*
> +	 * Value returned in iob0 will have the number of supported performance
> +	 * modes per device. The performance mode values will then be given as a
> +	 * list after this (iob1-iobX). Loop through the supported values and
> +	 * enable their mapped platform_profile choice, overriding "legacy"
> +	 * values along the way if a non-legacy value exists.
> +	 */
> +	for (i = 1; i <= buf.iob0; i++) {
> +		dev_dbg(&galaxybook->platform->dev,
> +			"device supports performance mode 0x%x\n", buf.iob_values[i]);
> +		err = get_performance_mode_profile(galaxybook, buf.iob_values[i], &profile);

Here we pass iob_values[i] through a switch-case block inside
get_performance_mode_profile() and then we do it again bellow. Maybe
this all could be done here, without having to call
get_performance_mode_profile().

> +		if (err)
> +			continue;
> +		switch (buf.iob_values[i]) {
> +		case GB_PERFORMANCE_MODE_OPTIMIZED:
> +			/* override legacy Optimized value */
> +			gb_pfmode(profile) = GB_PERFORMANCE_MODE_OPTIMIZED;
> +			break;
> +		case GB_PERFORMANCE_MODE_PERFORMANCE:
> +			/* override legacy Performance value */
> +			gb_pfmode(profile) = GB_PERFORMANCE_MODE_PERFORMANCE;
> +			break;
> +		case GB_PERFORMANCE_MODE_ULTRA:
> +			/*
> +			 * if Ultra is supported, downgrade performance to
> +			 * balanced-performance
> +			 */

I haven't been following the entire discussion, so I don't know if Armin
changed his mind but I agree with him. 

I think GB_PERFORMANCE_MODE_PERFORMANCE_LEGACY should be statically
mapped to BALANCED_PERFORMANCE and TURBO should be PERFORMANCE. This
would simplify a lot of the logic here.

> +			if (test_bit(PLATFORM_PROFILE_PERFORMANCE,
> +				     galaxybook->platform_profile_choices)) {
> +				gb_pfmode(PLATFORM_PROFILE_BALANCED_PERFORMANCE) =
> +					gb_pfmode(PLATFORM_PROFILE_PERFORMANCE);
> +				set_bit(PLATFORM_PROFILE_BALANCED_PERFORMANCE,
> +					galaxybook->platform_profile_choices);
> +			}
> +			/* override performance profile to use Ultra's value */
> +			gb_pfmode(profile) = GB_PERFORMANCE_MODE_ULTRA;
> +			break;
> +		default:
> +			break;
> +		}
> +		set_bit(profile, galaxybook->platform_profile_choices);
> +	}
> +
> +	err = galaxybook_performance_mode_init(galaxybook);

If the main goal of this method is to set an initial profile maybe we
can just directly set it after finding GB_PERFORMANCE_MODE_OPTIMIZED?

This would eliminate a bit of indirection.

Do you know if all devices support OPTIMIZED? either legacy or
non-legacy.

> +	if (err) {
> +		dev_dbg(&galaxybook->platform->dev,
> +			"failed to initialize performance mode, error %d\n", err);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int galaxybook_platform_profile_init(struct samsung_galaxybook *galaxybook)
> +{
> +	struct device *ppdev;
> +	int err;
> +
> +	err = galaxybook_performance_mode_profile_init(galaxybook);
> +	if (err)
> +		return 0;
> +
> +	galaxybook->has_performance_mode = true;
> +
> +	ppdev = devm_platform_profile_register(&galaxybook->platform->dev, DRIVER_NAME,
> +					       galaxybook, &galaxybook_platform_profile_ops);
> +	if (IS_ERR(ppdev))
> +		return PTR_ERR(ppdev);
> +
> +	platform_profile_notify(ppdev);

No need to notify after registering. You can directly return
PTR_ERR_OR_ZERO().

~ Kurt

> <snip>
Joshua Grisham Jan. 18, 2025, 7:51 p.m. UTC | #2
Hi Kurt, thanks for getting back so fast on this!

Den lör 18 jan. 2025 kl 08:04 skrev Kurt Borja <kuurtb@gmail.com>:
>
> Hi Joshua,
>
> I have some comments on the platform profile section. The most important
> one is the platform_profile probe one, the rest are suggetions.
>
> ...
> > +static int galaxybook_platform_profile_probe(void *drvdata, unsigned long *choices)
> > +{
> > +     struct samsung_galaxybook *galaxybook = drvdata;
> > +     int i;
> > +
> > +     for_each_set_bit(i, galaxybook->platform_profile_choices, PLATFORM_PROFILE_LAST)
> > +             set_bit(i, choices);
>
> The intended use of this callback is to "probe" for available choices
> here. You should move all galaxybook_performance_mode_profile_init()
> logic to this method. This would eliminate the need to have a copy of
> the choices bitmap.
>

Yes at first I was really thinking a lot about how to cleanly break
apart the logic as I wanted it to work so that if this feature is not
supported on the particular device (e.g. the ACPI methods return an
error code, so you can assume that this feature does not exist on this
device, as is the case for SAM0427 devices for example, possibly
others that I am not aware of..) that we would not even try to create
the platform profile device.

I think I have decided now that maybe a fair amount of this was sub
optimization and I will instead now just try to do a "get" of the
current performance_mode using the ACPI method as a sort of litmus
test if the feature is working or not (just exactly as I have done on
most of the other features) in the galaxybook_platform_profile_init;
if that fails, then I will exit gracefully without trying to create
the platform_profile (return 0), otherwise I will pass all of the rest
to the probe function and if it fails, it fails :) (because, remember,
in theory we were able to successfully get the value using ACPI so the
feature *should* work at that point, right?)

> > +static int galaxybook_performance_mode_init(struct samsung_galaxybook *galaxybook)
> > +{
> > +     enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
> > +     u8 performance_mode;
> > +     int err;
> > +     int i;
> > +
> > +     err = performance_mode_acpi_get(galaxybook, &performance_mode);
> > +     if (err)
> > +             return err;
> > +
> > +     err = get_performance_mode_profile(galaxybook, performance_mode, &profile);
> > +     if (err)
>
> If this method failed we can't safely continue. I think you should
> return here, else you may get an out of bounds access bellow.
>
> > +             dev_warn(&galaxybook->platform->dev,
> > +                      "initial startup performance mode 0x%x is not mapped\n",
> > +                      performance_mode);
> > +
> > +     for_each_set_bit(i, galaxybook->platform_profile_choices, PLATFORM_PROFILE_LAST)
> > +             dev_dbg(&galaxybook->platform->dev,
> > +                     "enabled platform profile %d using performance mode 0x%x\n",
> > +                     i, galaxybook->profile_performance_modes[i]);
>
> Maybe we can log this directly in the switch-case block inside
> galaxybook_performance_mode_profile_init() instead of having to iterate.
>

Both of these (and the entirety of how this
galaxybook_performance_mode_init() is working) I also realized are sub
optimizations .. the only thing they are really helping is the case
where someone loads removes and then loads the module again (I did not
want that their performance_mode should be updated if they had already
set a valid one previously in their session). But, yeah, that is a
super corner case and the code should not be extra complicated for
that (is what I am now thinking instead, anyway), so I think now I
will just force set the initial performance_mode on probe to what was
eventually mapped as Balanced and if someone is removing and reloading
the module in their session, they are probably capable of dealing with
the profile being reset to balanced each time :)

(Existing userspace tools like power-profiles-daemon etc are taking
care of "restoring" your session's last-used profile after startup so
even after this init sets to Balanced then userspace tools will kick
in to set it to something else later that you probably wanted/last
used anyway; this has been my experience, anyway!, so I am not worried
about setting to Balanced at Init but the reason to set anything is
because of how the ACPI Get method always responds with 0 after
startup, so I just want that it sets something that should actually be
used according to the result of the mapping -- same behavior as the
Samsung Windows apps).

> > +     /*
> > +      * Value returned in iob0 will have the number of supported performance
> > +      * modes per device. The performance mode values will then be given as a
> > +      * list after this (iob1-iobX). Loop through the supported values and
> > +      * enable their mapped platform_profile choice, overriding "legacy"
> > +      * values along the way if a non-legacy value exists.
> > +      */
> > +     for (i = 1; i <= buf.iob0; i++) {
> > +             dev_dbg(&galaxybook->platform->dev,
> > +                     "device supports performance mode 0x%x\n", buf.iob_values[i]);
> > +             err = get_performance_mode_profile(galaxybook, buf.iob_values[i], &profile);
>
> Here we pass iob_values[i] through a switch-case block inside
> get_performance_mode_profile() and then we do it again bellow. Maybe
> this all could be done here, without having to call
> get_performance_mode_profile().
>

Yes I have cleaned this up in a new draft now also and re-shaped a bit
of how the debug messages look so it hopefully makes more sense and
there are not multiple unnecessary loops.

Note: the whole point of having the messages printed out to debug was
to help with troubleshooting as new devices or new BIOS updates make
things confusing, as I have seen this problem with several different
users and devices while initially writing the logic for this driver
out of tree... so they do help a lot!

> > +             if (err)
> > +                     continue;
> > +             switch (buf.iob_values[i]) {
> > +             case GB_PERFORMANCE_MODE_OPTIMIZED:
> > +                     /* override legacy Optimized value */
> > +                     gb_pfmode(profile) = GB_PERFORMANCE_MODE_OPTIMIZED;
> > +                     break;
> > +             case GB_PERFORMANCE_MODE_PERFORMANCE:
> > +                     /* override legacy Performance value */
> > +                     gb_pfmode(profile) = GB_PERFORMANCE_MODE_PERFORMANCE;
> > +                     break;
> > +             case GB_PERFORMANCE_MODE_ULTRA:
> > +                     /*
> > +                      * if Ultra is supported, downgrade performance to
> > +                      * balanced-performance
> > +                      */
>
> I haven't been following the entire discussion, so I don't know if Armin
> changed his mind but I agree with him.
>
> I think GB_PERFORMANCE_MODE_PERFORMANCE_LEGACY should be statically
> mapped to BALANCED_PERFORMANCE and TURBO should be PERFORMANCE. This
> would simplify a lot of the logic here.
>

I was a bit worried about this, especially how it would potentially
interplay with other things such as power-profiles-daemon when
bringing in intel_pstate or anything else (it did not sit very well
for me to have a mode on my device that really felt like "High
Performance" but only call it "Balanced Performance" and worried that
it could be aggregated in the wrong way which could impact other
things etc etc .... )

BUT.. none of that matters now, as I have some news on this front: I
did a bit more digging and a bit more homework to really think through
this again, including going back through all of my notes and feedback
plus various log files given by multiple different users, for multiple
different devices in
https://github.com/joshuagrisham/samsung-galaxybook-extras/issues/31,
and then did some detective work looking up how the Samsung Settings
app looks for Ultra devices (looking where reviewers even posted
screenshots of the settings application for these devices in Windows,
etc...).

What I came to realize is that the Ultra devices do not use BOTH
"Performance" and "Ultra", but instead it actually just re-maps the
value for "Ultra" to use AS "Performance". So, they only have 3 modes
in Windows: "Quiet", "Optimized", and "High Performance" (they do not
have a fourth option for "Ultra"). The right solution then is to
re-map so that when a user selects PLATFORM_PROFILE_PERFORMANCE on an
Ultra device, it should send the "Ultra" Galaxy Book performance mode
to the ACPI method.

This should then support a lot more "hard coding" of the mapping and I
have cleaned it up significantly due to this.

Also, I have now tweaked the names of all of the internal symbols to
more closely match the internal names of these modes used by Samsung's
driver and services in Windows so that it will be easier to
troubleshoot and make sense of in the future, as well (e.g. what I had
called "Silent" they actually call "FanOff" etc..). I think it will
help a lot to just re-use their existing names instead of having yet
another "mapping layer" to sort through while troubleshooting.

> > +                     if (test_bit(PLATFORM_PROFILE_PERFORMANCE,
> > +                                  galaxybook->platform_profile_choices)) {
> > +                             gb_pfmode(PLATFORM_PROFILE_BALANCED_PERFORMANCE) =
> > +                                     gb_pfmode(PLATFORM_PROFILE_PERFORMANCE);
> > +                             set_bit(PLATFORM_PROFILE_BALANCED_PERFORMANCE,
> > +                                     galaxybook->platform_profile_choices);
> > +                     }
> > +                     /* override performance profile to use Ultra's value */
> > +                     gb_pfmode(profile) = GB_PERFORMANCE_MODE_ULTRA;
> > +                     break;
> > +             default:
> > +                     break;
> > +             }
> > +             set_bit(profile, galaxybook->platform_profile_choices);
> > +     }
> > +
> > +     err = galaxybook_performance_mode_init(galaxybook);
>
> If the main goal of this method is to set an initial profile maybe we
> can just directly set it after finding GB_PERFORMANCE_MODE_OPTIMIZED?
>
> This would eliminate a bit of indirection.
>
> Do you know if all devices support OPTIMIZED? either legacy or
> non-legacy.
>

Yes as mentioned above I have decided to rip out all of the sub
optimization here and do as you say: just set the value mapped to
PLATFORM_PROFILE_BALANCED after all of the mapping values are updated
(as long as it was set it in `choices`) and move on from there. I have
not seen any device so far that does not support at least one of the
Optmized modes, but by checking if PLATFORM_PROFILE_BALANCED is set
before using it then the worst that can happen is that the startup
value is something new not actually currently mapped in
get_performance_mode_profile() and it will be "fixed" the next time a
platform_profile_cycle() runs and sets everything back on track.

Does that sound ok or do you think it is better to try and leave in
some of this conditional / detection logic like was here in v7 that I
am now removing?

> > +static int galaxybook_platform_profile_init(struct samsung_galaxybook *galaxybook)
> > +{
> > +     struct device *ppdev;
> > +     int err;
> > +
> > +     err = galaxybook_performance_mode_profile_init(galaxybook);
> > +     if (err)
> > +             return 0;
> > +
> > +     galaxybook->has_performance_mode = true;
> > +
> > +     ppdev = devm_platform_profile_register(&galaxybook->platform->dev, DRIVER_NAME,
> > +                                            galaxybook, &galaxybook_platform_profile_ops);
> > +     if (IS_ERR(ppdev))
> > +             return PTR_ERR(ppdev);
> > +
> > +     platform_profile_notify(ppdev);
>
> No need to notify after registering. You can directly return
> PTR_ERR_OR_ZERO().
>
> ~ Kurt
>
> > <snip>

I think the reason I was thinking to notify was because we are
changing this performance mode during init but I see now that it is
already done in platform_profile_register() so yes I will clean this
up as well :)

v8 coming shortly, hopefully we are getting there!

Thanks again and regards,
Joshua
diff mbox series

Patch

diff --git a/Documentation/admin-guide/laptops/index.rst b/Documentation/admin-guide/laptops/index.rst
index cd9a1c2695fd..e71c8984c23e 100644
--- a/Documentation/admin-guide/laptops/index.rst
+++ b/Documentation/admin-guide/laptops/index.rst
@@ -11,6 +11,7 @@  Laptop Drivers
    disk-shock-protection
    laptop-mode
    lg-laptop
+   samsung-galaxybook
    sony-laptop
    sonypi
    thinkpad-acpi
diff --git a/Documentation/admin-guide/laptops/samsung-galaxybook.rst b/Documentation/admin-guide/laptops/samsung-galaxybook.rst
new file mode 100644
index 000000000000..f6af0c84de2c
--- /dev/null
+++ b/Documentation/admin-guide/laptops/samsung-galaxybook.rst
@@ -0,0 +1,170 @@ 
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+===================
+Samsung Galaxy Book
+===================
+
+Joshua Grisham <josh@joshuagrisham.com>
+
+This is a Linux x86 platform driver for Samsung Galaxy Book series notebook
+devices which utilizes Samsung's ``SCAI`` ACPI device in order to control
+extra features and receive various notifications.
+
+Supported devices
+=================
+
+Any device with one of the supported ACPI device IDs should be supported. This
+covers most of the "Samsung Galaxy Book" series notebooks that are currently
+available as of this writing, and could include other Samsung notebook devices
+as well.
+
+Status
+======
+
+The following features are currently supported:
+
+- :ref:`Keyboard backlight <keyboard-backlight>` control
+- :ref:`Performance mode <performance-mode>` control implemented using the
+  platform profile interface
+- :ref:`Battery charge control end threshold
+  <battery-charge-control-end-threshold>` (stop charging battery at given
+  percentage value) implemented as a battery hook
+- :ref:`Firmware Attributes <firmware-attributes>` to allow control of various
+  device settings
+- :ref:`Handling of Fn hotkeys <keyboard-hotkey-actions>` for various actions
+- :ref:`Handling of ACPI notifications and hotkeys
+  <acpi-notifications-and-hotkey-actions>`
+
+Because different models of these devices can vary in their features, there is
+logic built within the driver which attempts to test each implemented feature
+for a valid response before enabling its support (registering additional devices
+or extensions, adding sysfs attributes, etc). Therefore, it can be important to
+note that not all features may be supported for your particular device.
+
+The following features might be possible to implement but will require
+additional investigation and are therefore not supported at this time:
+
+- "Dolby Atmos" mode for the speakers
+- "Outdoor Mode" for increasing screen brightness on models with ``SAM0427``
+- "Silent Mode" on models with ``SAM0427``
+
+.. _keyboard-backlight:
+
+Keyboard backlight
+==================
+
+A new LED class named ``samsung-galaxybook::kbd_backlight`` is created which
+will then expose the device using the standard sysfs-based LED interface at
+``/sys/class/leds/samsung-galaxybook::kbd_backlight``. Brightness can be
+controlled by writing the desired value to the ``brightness`` sysfs attribute or
+with any other desired userspace utility.
+
+.. note::
+  Most of these devices have an ambient light sensor which also turns
+  off the keyboard backlight under well-lit conditions. This behavior does not
+  seem possible to control at this time, but can be good to be aware of.
+
+.. _performance-mode:
+
+Performance mode
+================
+
+This driver implements the
+Documentation/userspace-api/sysfs-platform_profile.rst interface for working
+with the "performance mode" function of the Samsung ACPI device.
+
+Mapping of each Samsung "performance mode" to its respective platform profile is
+performed dynamically by the driver, as not all models support all of the same
+performance modes. Your device might have one or more of the following mappings:
+
+- "Silent" maps to ``low-power``
+- "Quiet" maps to ``quiet``
+- "Optimized" maps to ``balanced``
+- "Performance" maps to ``performance``
+- For devices which support "Ultra", "Ultra" will map to ``performance`` and
+  "Performance" will be re-mapped to ``balanced-performance``.
+
+The result of the mapping can be printed in the kernel log when the module is
+loaded. Supported profiles can also be retrieved from
+``/sys/firmware/acpi/platform_profile_choices``, while
+``/sys/firmware/acpi/platform_profile`` can be used to read or write the
+currently selected profile.
+
+The ``balanced`` platform profile will be set during module load if no profile
+has been previously set.
+
+.. _battery-charge-control-end-threshold:
+
+Battery charge control end threshold
+====================================
+
+This platform driver will add the ability to set the battery's charge control
+end threshold, but does not have the ability to set a start threshold.
+
+This feature is typically called "Battery Saver" by the various Samsung
+applications in Windows, but in Linux we have implemented the standardized
+"charge control threshold" sysfs interface on the battery device to allow for
+controlling this functionality from the userspace.
+
+The sysfs attribute
+``/sys/class/power_supply/BAT1/charge_control_end_threshold`` can be used to
+read or set the desired charge end threshold.
+
+If you wish to maintain interoperability with Windows, then you should set the
+value to 80 to represent "on", or 100 to represent "off", as these are the
+values currently recognized by the various Windows-based Samsung applications
+and services as "on" or "off". Otherwise, the device will accept any value
+between 1 and 100 as the percentage that you wish the battery to stop charging
+at.
+
+.. _firmware-attributes:
+
+Firmware Attributes
+===================
+
+The following enumeration-typed firmware attributes are set up by this driver
+and should be accessible under
+``/sys/class/firmware-attributes/samsung-galaxybook/attributes/`` if your device
+supports them:
+
+- ``power_on_lid_open`` (device should power on when the lid is opened)
+- ``usb_charging``  (USB ports can deliver power to connected devices even when
+  the device is powered off or in a low sleep state)
+- ``block_recording`` (blocks access to camera and microphone)
+
+All of these attributes are simple boolean-like enumeration values which use 0
+to represent "off" and 1 to represent "on". Use the ``current_value`` attribute
+to get or change the setting on the device.
+
+Note that when ``block_recording`` is updated, the input device "Samsung Galaxy
+Book Lens Cover" will receive a ``SW_CAMERA_LENS_COVER`` switch event which
+reflects the current state.
+
+.. _keyboard-hotkey-actions:
+
+Keyboard hotkey actions (i8042 filter)
+======================================
+
+The i8042 filter will swallow the keyboard events for the Fn+F9 hotkey (Multi-
+level keyboard backlight toggle) and Fn+F10 hotkey (Block recording toggle)
+and instead execute their actions within the driver itself.
+
+Fn+F9 will cycle through the brightness levels of the keyboard backlight. A
+notification will be sent using ``led_classdev_notify_brightness_hw_changed``
+so that the userspace can be aware of the change. This mimics the behavior of
+other existing devices where the brightness level is cycled internally by the
+embedded controller and then reported via a notification.
+
+Fn+F10 will toggle the value of the "block recording" setting, which blocks
+or allows usage of the built-in camera and microphone.
+
+.. _acpi-notifications-and-hotkey-actions:
+
+ACPI notifications and hotkey actions
+=====================================
+
+ACPI notifications will generate ACPI netlink events and can be received using
+userspace tools such as ``acpi_listen`` and ``acpid``.
+
+The Fn+F11 Performance mode hotkey will be handled by the driver; each keypress
+will cycle to the next available platform profile.
diff --git a/MAINTAINERS b/MAINTAINERS
index 3809931b9240..6448e931728c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20733,6 +20733,13 @@  L:	linux-fbdev@vger.kernel.org
 S:	Maintained
 F:	drivers/video/fbdev/s3c-fb.c
 
+SAMSUNG GALAXY BOOK DRIVER
+M:	Joshua Grisham <josh@joshuagrisham.com>
+L:	platform-driver-x86@vger.kernel.org
+S:	Maintained
+F:	Documentation/admin-guide/laptops/samsung-galaxybook.rst
+F:	drivers/platform/x86/samsung-galaxybook.c
+
 SAMSUNG INTERCONNECT DRIVERS
 M:	Sylwester Nawrocki <s.nawrocki@samsung.com>
 M:	Artur Świgoń <a.swigon@samsung.com>
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 0258dd879d64..c77178e2640b 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -778,6 +778,23 @@  config BARCO_P50_GPIO
 	  To compile this driver as a module, choose M here: the module
 	  will be called barco-p50-gpio.
 
+config SAMSUNG_GALAXYBOOK
+	tristate "Samsung Galaxy Book driver"
+	depends on ACPI
+	depends on ACPI_BATTERY
+	depends on INPUT
+	depends on LEDS_CLASS
+	depends on SERIO_I8042
+	select ACPI_PLATFORM_PROFILE
+	select FW_ATTR_CLASS
+	help
+	  This is a driver for Samsung Galaxy Book series notebooks. It adds
+	  support for the keyboard backlight control, performance mode control,
+	  function keys, and various firmware attributes.
+
+	  For more information about this driver, see
+	  <file:Documentation/admin-guide/laptops/samsung-galaxybook.rst>.
+
 config SAMSUNG_LAPTOP
 	tristate "Samsung Laptop driver"
 	depends on RFKILL || RFKILL = n
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index e1b142947067..32ec4cb9d902 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -95,8 +95,9 @@  obj-$(CONFIG_PCENGINES_APU2)	+= pcengines-apuv2.o
 obj-$(CONFIG_BARCO_P50_GPIO)	+= barco-p50-gpio.o
 
 # Samsung
-obj-$(CONFIG_SAMSUNG_LAPTOP)	+= samsung-laptop.o
-obj-$(CONFIG_SAMSUNG_Q10)	+= samsung-q10.o
+obj-$(CONFIG_SAMSUNG_GALAXYBOOK)	+= samsung-galaxybook.o
+obj-$(CONFIG_SAMSUNG_LAPTOP)		+= samsung-laptop.o
+obj-$(CONFIG_SAMSUNG_Q10)		+= samsung-q10.o
 
 # Toshiba
 obj-$(CONFIG_TOSHIBA_BT_RFKILL)	+= toshiba_bluetooth.o
diff --git a/drivers/platform/x86/samsung-galaxybook.c b/drivers/platform/x86/samsung-galaxybook.c
new file mode 100644
index 000000000000..50c975c66c13
--- /dev/null
+++ b/drivers/platform/x86/samsung-galaxybook.c
@@ -0,0 +1,1506 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Samsung Galaxy Book driver
+ *
+ * Copyright (c) 2025 Joshua Grisham <josh@joshuagrisham.com>
+ *
+ * With contributions to the SCAI ACPI device interface:
+ * Copyright (c) 2024 Giulio Girardi <giulio.girardi@protechgroup.it>
+ *
+ * Implementation inspired by existing x86 platform drivers.
+ * Thank you to the authors!
+ */
+
+#include <linux/acpi.h>
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/i8042.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/platform_profile.h>
+#include <linux/serio.h>
+#include <linux/sysfs.h>
+#include <linux/uuid.h>
+#include <linux/workqueue.h>
+#include <acpi/battery.h>
+#include "firmware_attributes_class.h"
+
+#define DRIVER_NAME "samsung-galaxybook"
+
+struct samsung_galaxybook {
+	struct platform_device *platform;
+	struct acpi_device *acpi;
+
+	struct device *fw_attrs_dev;
+	struct kset *fw_attrs_kset;
+	/* block in case firmware attributes are updated in multiple threads */
+	struct mutex fw_attr_lock;
+
+	bool has_kbd_backlight;
+	bool has_block_recording;
+	bool has_performance_mode;
+
+	struct led_classdev kbd_backlight;
+	struct work_struct kbd_backlight_hotkey_work;
+	/* block in case brightness updated using hotkey and another thread */
+	struct mutex kbd_backlight_lock;
+
+	void *i8042_filter_ptr;
+
+	struct work_struct block_recording_hotkey_work;
+	struct input_dev *camera_lens_cover_switch;
+
+	struct acpi_battery_hook battery_hook;
+	struct device_attribute charge_control_end_threshold_attr;
+
+	u8 profile_performance_modes[PLATFORM_PROFILE_LAST + 1];
+	unsigned long platform_profile_choices[BITS_TO_LONGS(PLATFORM_PROFILE_LAST)];
+};
+
+enum galaxybook_fw_attr_id {
+	GB_ATTR_POWER_ON_LID_OPEN,
+	GB_ATTR_USB_CHARGING,
+	GB_ATTR_BLOCK_RECORDING,
+};
+
+static const char * const galaxybook_fw_attr_name[] = {
+	[GB_ATTR_POWER_ON_LID_OPEN] = "power_on_lid_open",
+	[GB_ATTR_USB_CHARGING]      = "usb_charging",
+	[GB_ATTR_BLOCK_RECORDING]   = "block_recording",
+};
+
+static const char * const galaxybook_fw_attr_desc[] = {
+	[GB_ATTR_POWER_ON_LID_OPEN] = "Power On Lid Open",
+	[GB_ATTR_USB_CHARGING]      = "USB Charging",
+	[GB_ATTR_BLOCK_RECORDING]   = "Block Recording",
+};
+
+#define GB_ATTR_LANGUAGE_CODE "en_US.UTF-8"
+
+struct galaxybook_fw_attr {
+	struct samsung_galaxybook *galaxybook;
+	enum galaxybook_fw_attr_id fw_attr_id;
+	struct attribute_group attr_group;
+	struct kobj_attribute display_name;
+	struct kobj_attribute current_value;
+	int (*get_value)(struct samsung_galaxybook *galaxybook, bool *value);
+	int (*set_value)(struct samsung_galaxybook *galaxybook, const bool value);
+};
+
+struct sawb {
+	u16 safn;
+	u16 sasb;
+	u8 rflg;
+	union {
+		struct {
+			u8 gunm;
+			u8 guds[250];
+		} __packed;
+		struct {
+			u8 caid[16];
+			u8 fncn;
+			u8 subn;
+			u8 iob0;
+			u8 iob1;
+			u8 iob2;
+			u8 iob3;
+			u8 iob4;
+			u8 iob5;
+			u8 iob6;
+			u8 iob7;
+			u8 iob8;
+			u8 iob9;
+		} __packed;
+		struct {
+			u8 iob_prefix[18];
+			u8 iob_values[10];
+		} __packed;
+	} __packed;
+} __packed;
+
+#define GB_SAWB_LEN_SETTINGS          0x15
+#define GB_SAWB_LEN_PERFORMANCE_MODE  0x100
+
+#define GB_SAFN  0x5843
+
+#define GB_SASB_KBD_BACKLIGHT     0x78
+#define GB_SASB_POWER_MANAGEMENT  0x7a
+#define GB_SASB_USB_CHARGING_GET  0x67
+#define GB_SASB_USB_CHARGING_SET  0x68
+#define GB_SASB_NOTIFICATIONS     0x86
+#define GB_SASB_BLOCK_RECORDING   0x8a
+#define GB_SASB_PERFORMANCE_MODE  0x91
+
+#define GB_SAWB_RFLG_POS     4
+#define GB_SAWB_GB_GUNM_POS  5
+
+#define GB_RFLG_SUCCESS  0xaa
+#define GB_GUNM_FAIL     0xff
+
+#define GB_GUNM_FEATURE_ENABLE          0xbb
+#define GB_GUNM_FEATURE_ENABLE_SUCCESS  0xdd
+#define GB_GUDS_FEATURE_ENABLE          0xaa
+#define GB_GUDS_FEATURE_ENABLE_SUCCESS  0xcc
+
+#define GB_GUNM_GET  0x81
+#define GB_GUNM_SET  0x82
+
+#define GB_GUNM_POWER_MANAGEMENT  0x82
+
+#define GB_GUNM_USB_CHARGING_GET            0x80
+#define GB_GUNM_USB_CHARGING_ON             0x81
+#define GB_GUNM_USB_CHARGING_OFF            0x80
+#define GB_GUDS_POWER_ON_LID_OPEN           0xa3
+#define GB_GUDS_POWER_ON_LID_OPEN_GET       0x81
+#define GB_GUDS_POWER_ON_LID_OPEN_SET       0x80
+#define GB_GUDS_BATTERY_CHARGE_CONTROL      0xe9
+#define GB_GUDS_BATTERY_CHARGE_CONTROL_GET  0x91
+#define GB_GUDS_BATTERY_CHARGE_CONTROL_SET  0x90
+#define GB_GUNM_ACPI_NOTIFY_ENABLE          0x80
+#define GB_GUDS_ACPI_NOTIFY_ENABLE          0x02
+
+#define GB_BLOCK_RECORDING_ON   0x0
+#define GB_BLOCK_RECORDING_OFF  0x1
+
+#define GB_FNCN_PERFORMANCE_MODE       0x51
+#define GB_SUBN_PERFORMANCE_MODE_LIST  0x01
+#define GB_SUBN_PERFORMANCE_MODE_GET   0x02
+#define GB_SUBN_PERFORMANCE_MODE_SET   0x03
+
+/* guid 8246028d-8bca-4a55-ba0f-6f1e6b921b8f */
+static const guid_t performance_mode_guid =
+	GUID_INIT(0x8246028d, 0x8bca, 0x4a55, 0xba, 0x0f, 0x6f, 0x1e, 0x6b, 0x92, 0x1b, 0x8f);
+#define GB_PERFORMANCE_MODE_GUID performance_mode_guid
+
+#define GB_PERFORMANCE_MODE_ULTRA               0x16
+#define GB_PERFORMANCE_MODE_PERFORMANCE         0x15
+#define GB_PERFORMANCE_MODE_SILENT              0xb
+#define GB_PERFORMANCE_MODE_QUIET               0xa
+#define GB_PERFORMANCE_MODE_OPTIMIZED           0x2
+#define GB_PERFORMANCE_MODE_PERFORMANCE_LEGACY  0x1
+#define GB_PERFORMANCE_MODE_OPTIMIZED_LEGACY    0x0
+#define GB_PERFORMANCE_MODE_IGNORE1             0x14
+#define GB_PERFORMANCE_MODE_IGNORE2             0xc
+#define GB_PERFORMANCE_MODE_INVALID             0xff
+
+#define GB_ACPI_METHOD_ENABLE            "SDLS"
+#define GB_ACPI_METHOD_ENABLE_ON         1
+#define GB_ACPI_METHOD_ENABLE_OFF        0
+#define GB_ACPI_METHOD_SETTINGS          "CSFI"
+#define GB_ACPI_METHOD_PERFORMANCE_MODE  "CSXI"
+
+#define GB_KBD_BACKLIGHT_MAX_BRIGHTNESS  3
+
+#define GB_ACPI_NOTIFY_BATTERY_STATE_CHANGED    0x61
+#define GB_ACPI_NOTIFY_DEVICE_ON_TABLE          0x6c
+#define GB_ACPI_NOTIFY_DEVICE_OFF_TABLE         0x6d
+#define GB_ACPI_NOTIFY_HOTKEY_PERFORMANCE_MODE  0x70
+
+#define GB_KEY_KBD_BACKLIGHT_KEYDOWN    0x2c
+#define GB_KEY_KBD_BACKLIGHT_KEYUP      0xac
+#define GB_KEY_BLOCK_RECORDING_KEYDOWN  0x1f
+#define GB_KEY_BLOCK_RECORDING_KEYUP    0x9f
+#define GB_KEY_BATTERY_NOTIFY_KEYUP     0xf
+#define GB_KEY_BATTERY_NOTIFY_KEYDOWN   0x8f
+
+/*
+ * ACPI method handling
+ */
+
+static int galaxybook_acpi_method(struct samsung_galaxybook *galaxybook, acpi_string method,
+				  struct sawb *buf, size_t len)
+{
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+	union acpi_object in_obj, *out_obj;
+	struct acpi_object_list input;
+	acpi_status status;
+	int err;
+
+	in_obj.type = ACPI_TYPE_BUFFER;
+	in_obj.buffer.length = len;
+	in_obj.buffer.pointer = (u8 *)buf;
+
+	input.count = 1;
+	input.pointer = &in_obj;
+
+	status = acpi_evaluate_object_typed(galaxybook->acpi->handle, method, &input, &output,
+					    ACPI_TYPE_BUFFER);
+
+	if (ACPI_FAILURE(status)) {
+		dev_err(&galaxybook->acpi->dev, "failed to execute method %s; got %s\n",
+			method, acpi_format_exception(status));
+		return -EIO;
+	}
+
+	out_obj = output.pointer;
+
+	if (out_obj->buffer.length != len || out_obj->buffer.length < GB_SAWB_GB_GUNM_POS + 1) {
+		dev_err(&galaxybook->acpi->dev,
+			"failed to execute %s; response length mismatch\n",
+			method);
+		err = -EPROTO;
+		goto out_free;
+	}
+	if (out_obj->buffer.pointer[GB_SAWB_RFLG_POS] != GB_RFLG_SUCCESS) {
+		dev_err(&galaxybook->acpi->dev,
+			"failed to execute %s; device did not respond with success code 0x%x\n",
+			method, GB_RFLG_SUCCESS);
+		err = -ENXIO;
+		goto out_free;
+	}
+	if (out_obj->buffer.pointer[GB_SAWB_GB_GUNM_POS] == GB_GUNM_FAIL) {
+		dev_err(&galaxybook->acpi->dev,
+			"failed to execute %s; device responded with failure code 0x%x\n",
+			method, GB_GUNM_FAIL);
+		err = -ENXIO;
+		goto out_free;
+	}
+
+	memcpy(buf, out_obj->buffer.pointer, len);
+	err = 0;
+
+out_free:
+	kfree(out_obj);
+	return err;
+}
+
+static int galaxybook_enable_acpi_feature(struct samsung_galaxybook *galaxybook, const u16 sasb)
+{
+	struct sawb buf = {};
+	int err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = sasb;
+	buf.gunm = GB_GUNM_FEATURE_ENABLE;
+	buf.guds[0] = GB_GUDS_FEATURE_ENABLE;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				     &buf, GB_SAWB_LEN_SETTINGS);
+	if (err)
+		return err;
+
+	if (buf.gunm != GB_GUNM_FEATURE_ENABLE_SUCCESS &&
+	    buf.guds[0] != GB_GUDS_FEATURE_ENABLE_SUCCESS)
+		return -ENODEV;
+
+	return 0;
+}
+
+/*
+ * Keyboard Backlight
+ */
+
+static int kbd_backlight_acpi_set(struct samsung_galaxybook *galaxybook,
+				  const enum led_brightness brightness)
+{
+	struct sawb buf = {};
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_KBD_BACKLIGHT;
+	buf.gunm = GB_GUNM_SET;
+
+	buf.guds[0] = brightness;
+
+	return galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				      &buf, GB_SAWB_LEN_SETTINGS);
+}
+
+static int kbd_backlight_acpi_get(struct samsung_galaxybook *galaxybook,
+				  enum led_brightness *brightness)
+{
+	struct sawb buf = {};
+	int err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_KBD_BACKLIGHT;
+	buf.gunm = GB_GUNM_GET;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				     &buf, GB_SAWB_LEN_SETTINGS);
+	if (err)
+		return err;
+
+	*brightness = buf.gunm;
+
+	return 0;
+}
+
+static int kbd_backlight_store(struct led_classdev *led,
+			       const enum led_brightness brightness)
+{
+	struct samsung_galaxybook *galaxybook =
+		container_of_const(led, struct samsung_galaxybook, kbd_backlight);
+
+	return kbd_backlight_acpi_set(galaxybook, brightness);
+}
+
+static enum led_brightness kbd_backlight_show(struct led_classdev *led)
+{
+	struct samsung_galaxybook *galaxybook =
+		container_of(led, struct samsung_galaxybook, kbd_backlight);
+	enum led_brightness brightness;
+	int err;
+
+	err = kbd_backlight_acpi_get(galaxybook, &brightness);
+	if (err)
+		return err;
+
+	return brightness;
+}
+
+static int galaxybook_kbd_backlight_init(struct samsung_galaxybook *galaxybook)
+{
+	struct led_init_data init_data = {};
+	enum led_brightness brightness;
+	int err;
+
+	err = devm_mutex_init(&galaxybook->platform->dev, &galaxybook->kbd_backlight_lock);
+	if (err)
+		return err;
+
+	err = galaxybook_enable_acpi_feature(galaxybook, GB_SASB_KBD_BACKLIGHT);
+	if (err) {
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to enable kbd_backlight feature, error %d\n", err);
+		return 0;
+	}
+
+	err = kbd_backlight_acpi_get(galaxybook, &brightness);
+	if (err) {
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to get initial kbd_backlight brightness, error %d\n", err);
+		return 0;
+	}
+
+	init_data.devicename = DRIVER_NAME;
+	init_data.default_label = ":" LED_FUNCTION_KBD_BACKLIGHT;
+	init_data.devname_mandatory = true;
+
+	galaxybook->kbd_backlight.brightness_get = kbd_backlight_show;
+	galaxybook->kbd_backlight.brightness_set_blocking = kbd_backlight_store;
+	galaxybook->kbd_backlight.flags = LED_BRIGHT_HW_CHANGED;
+	galaxybook->kbd_backlight.max_brightness = GB_KBD_BACKLIGHT_MAX_BRIGHTNESS;
+
+	err = devm_led_classdev_register_ext(&galaxybook->platform->dev,
+					     &galaxybook->kbd_backlight, &init_data);
+	if (err)
+		return err;
+
+	galaxybook->has_kbd_backlight = true;
+
+	return 0;
+}
+
+/*
+ * Battery Extension (adds charge_control_end_threshold to the battery device)
+ */
+
+static int charge_control_end_threshold_acpi_set(struct samsung_galaxybook *galaxybook, u8 value)
+{
+	struct sawb buf = {};
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_POWER_MANAGEMENT;
+	buf.gunm = GB_GUNM_POWER_MANAGEMENT;
+	buf.guds[0] = GB_GUDS_BATTERY_CHARGE_CONTROL;
+	buf.guds[1] = GB_GUDS_BATTERY_CHARGE_CONTROL_SET;
+	buf.guds[2] = value;
+
+	return galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				      &buf, GB_SAWB_LEN_SETTINGS);
+}
+
+static int charge_control_end_threshold_acpi_get(struct samsung_galaxybook *galaxybook, u8 *value)
+{
+	struct sawb buf = {};
+	int err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_POWER_MANAGEMENT;
+	buf.gunm = GB_GUNM_POWER_MANAGEMENT;
+	buf.guds[0] = GB_GUDS_BATTERY_CHARGE_CONTROL;
+	buf.guds[1] = GB_GUDS_BATTERY_CHARGE_CONTROL_GET;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				     &buf, GB_SAWB_LEN_SETTINGS);
+	if (err)
+		return err;
+
+	*value = buf.guds[1];
+
+	return 0;
+}
+
+static ssize_t charge_control_end_threshold_store(struct device *dev, struct device_attribute *attr,
+						  const char *buf, size_t count)
+{
+	struct samsung_galaxybook *galaxybook =
+		container_of(attr, struct samsung_galaxybook, charge_control_end_threshold_attr);
+	u8 value;
+	int err;
+
+	if (!count)
+		return -EINVAL;
+
+	err = kstrtou8(buf, 0, &value);
+	if (err)
+		return err;
+
+	if (value < 1 || value > 100)
+		return -EINVAL;
+
+	/*
+	 * device stores "no end threshold" as 0 instead of 100;
+	 * if setting to 100, send 0
+	 */
+	if (value == 100)
+		value = 0;
+
+	err = charge_control_end_threshold_acpi_set(galaxybook, value);
+	if (err)
+		return err;
+
+	return count;
+}
+
+static ssize_t charge_control_end_threshold_show(struct device *dev, struct device_attribute *attr,
+						 char *buf)
+{
+	struct samsung_galaxybook *galaxybook =
+		container_of(attr, struct samsung_galaxybook, charge_control_end_threshold_attr);
+	u8 value;
+	int err;
+
+	err = charge_control_end_threshold_acpi_get(galaxybook, &value);
+	if (err)
+		return err;
+
+	/*
+	 * device stores "no end threshold" as 0 instead of 100;
+	 * if device has 0, report 100
+	 */
+	if (value == 0)
+		value = 100;
+
+	return sysfs_emit(buf, "%u\n", value);
+}
+
+static int galaxybook_battery_add(struct power_supply *battery, struct acpi_battery_hook *hook)
+{
+	struct samsung_galaxybook *galaxybook =
+		container_of(hook, struct samsung_galaxybook, battery_hook);
+
+	return device_create_file(&battery->dev, &galaxybook->charge_control_end_threshold_attr);
+}
+
+static int galaxybook_battery_remove(struct power_supply *battery, struct acpi_battery_hook *hook)
+{
+	struct samsung_galaxybook *galaxybook =
+		container_of(hook, struct samsung_galaxybook, battery_hook);
+
+	device_remove_file(&battery->dev, &galaxybook->charge_control_end_threshold_attr);
+	return 0;
+}
+
+static int galaxybook_battery_threshold_init(struct samsung_galaxybook *galaxybook)
+{
+	struct acpi_battery_hook *hook;
+	struct device_attribute *attr;
+	u8 value;
+	int err;
+
+	err = charge_control_end_threshold_acpi_get(galaxybook, &value);
+	if (err) {
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to get initial battery charge end threshold, error %d\n", err);
+		return 0;
+	}
+
+	hook = &galaxybook->battery_hook;
+	hook->add_battery = galaxybook_battery_add;
+	hook->remove_battery = galaxybook_battery_remove;
+	hook->name = "Samsung Galaxy Book Battery Extension";
+
+	attr = &galaxybook->charge_control_end_threshold_attr;
+	sysfs_attr_init(&attr->attr);
+	attr->attr.name = "charge_control_end_threshold";
+	attr->attr.mode = 0644;
+	attr->show = charge_control_end_threshold_show;
+	attr->store = charge_control_end_threshold_store;
+
+	return devm_battery_hook_register(&galaxybook->platform->dev, &galaxybook->battery_hook);
+}
+
+/*
+ * Platform Profile / Performance mode
+ */
+
+static int performance_mode_acpi_set(struct samsung_galaxybook *galaxybook,
+				     const u8 performance_mode)
+{
+	struct sawb buf = {};
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_PERFORMANCE_MODE;
+	export_guid(buf.caid, &GB_PERFORMANCE_MODE_GUID);
+	buf.fncn = GB_FNCN_PERFORMANCE_MODE;
+	buf.subn = GB_SUBN_PERFORMANCE_MODE_SET;
+	buf.iob0 = performance_mode;
+
+	return galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_PERFORMANCE_MODE,
+				      &buf, GB_SAWB_LEN_PERFORMANCE_MODE);
+}
+
+static int performance_mode_acpi_get(struct samsung_galaxybook *galaxybook, u8 *performance_mode)
+{
+	struct sawb buf = {};
+	int err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_PERFORMANCE_MODE;
+	export_guid(buf.caid, &GB_PERFORMANCE_MODE_GUID);
+	buf.fncn = GB_FNCN_PERFORMANCE_MODE;
+	buf.subn = GB_SUBN_PERFORMANCE_MODE_GET;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_PERFORMANCE_MODE,
+				     &buf, GB_SAWB_LEN_PERFORMANCE_MODE);
+	if (err)
+		return err;
+
+	*performance_mode = buf.iob0;
+
+	return 0;
+}
+
+static int get_performance_mode_profile(struct samsung_galaxybook *galaxybook,
+					const u8 performance_mode,
+					enum platform_profile_option *profile)
+{
+	switch (performance_mode) {
+	case GB_PERFORMANCE_MODE_SILENT:
+		*profile = PLATFORM_PROFILE_LOW_POWER;
+		break;
+	case GB_PERFORMANCE_MODE_QUIET:
+		*profile = PLATFORM_PROFILE_QUIET;
+		break;
+	case GB_PERFORMANCE_MODE_OPTIMIZED:
+	case GB_PERFORMANCE_MODE_OPTIMIZED_LEGACY:
+		*profile = PLATFORM_PROFILE_BALANCED;
+		break;
+	case GB_PERFORMANCE_MODE_PERFORMANCE:
+	case GB_PERFORMANCE_MODE_PERFORMANCE_LEGACY:
+		/* balanced-performance maps to Performance when Ultra exists */
+		if (test_bit(PLATFORM_PROFILE_BALANCED_PERFORMANCE,
+			     galaxybook->platform_profile_choices))
+			*profile = PLATFORM_PROFILE_BALANCED_PERFORMANCE;
+		else
+			*profile = PLATFORM_PROFILE_PERFORMANCE;
+		break;
+	case GB_PERFORMANCE_MODE_ULTRA:
+		*profile = PLATFORM_PROFILE_PERFORMANCE;
+		break;
+	case GB_PERFORMANCE_MODE_IGNORE1:
+	case GB_PERFORMANCE_MODE_IGNORE2:
+		return -EOPNOTSUPP;
+	default:
+		dev_warn(&galaxybook->platform->dev,
+			 "unrecognized performance mode 0x%x\n", performance_mode);
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int galaxybook_platform_profile_set(struct device *dev,
+					   enum platform_profile_option profile)
+{
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
+
+	return performance_mode_acpi_set(galaxybook,
+					 galaxybook->profile_performance_modes[profile]);
+}
+
+static int galaxybook_platform_profile_get(struct device *dev,
+					   enum platform_profile_option *profile)
+{
+	struct samsung_galaxybook *galaxybook = dev_get_drvdata(dev);
+	u8 performance_mode;
+	int err;
+
+	err = performance_mode_acpi_get(galaxybook, &performance_mode);
+	if (err)
+		return err;
+
+	return get_performance_mode_profile(galaxybook, performance_mode, profile);
+}
+
+static int galaxybook_platform_profile_probe(void *drvdata, unsigned long *choices)
+{
+	struct samsung_galaxybook *galaxybook = drvdata;
+	int i;
+
+	for_each_set_bit(i, galaxybook->platform_profile_choices, PLATFORM_PROFILE_LAST)
+		set_bit(i, choices);
+
+	return 0;
+}
+
+static const struct platform_profile_ops galaxybook_platform_profile_ops = {
+	.probe = galaxybook_platform_profile_probe,
+	.profile_get = galaxybook_platform_profile_get,
+	.profile_set = galaxybook_platform_profile_set,
+};
+
+static int galaxybook_performance_mode_init(struct samsung_galaxybook *galaxybook)
+{
+	enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
+	u8 performance_mode;
+	int err;
+	int i;
+
+	err = performance_mode_acpi_get(galaxybook, &performance_mode);
+	if (err)
+		return err;
+
+	err = get_performance_mode_profile(galaxybook, performance_mode, &profile);
+	if (err)
+		dev_warn(&galaxybook->platform->dev,
+			 "initial startup performance mode 0x%x is not mapped\n",
+			 performance_mode);
+
+	for_each_set_bit(i, galaxybook->platform_profile_choices, PLATFORM_PROFILE_LAST)
+		dev_dbg(&galaxybook->platform->dev,
+			"enabled platform profile %d using performance mode 0x%x\n",
+			i, galaxybook->profile_performance_modes[i]);
+
+	/* ensure startup performance_mode matches that mapped to its profile */
+	if (galaxybook->profile_performance_modes[profile] == performance_mode)
+		return 0;
+
+	/* otherwise, if balanced is enabled, use it as the default */
+	if (test_bit(PLATFORM_PROFILE_BALANCED, galaxybook->platform_profile_choices))
+		return performance_mode_acpi_set(galaxybook,
+			galaxybook->profile_performance_modes[PLATFORM_PROFILE_BALANCED]);
+
+	/* otherwise, find the first enabled profile and use that instead */
+	profile = find_next_bit_wrap(galaxybook->platform_profile_choices,
+				     PLATFORM_PROFILE_LAST,
+				     0);
+
+	if (profile == PLATFORM_PROFILE_LAST) {
+		dev_err(&galaxybook->platform->dev,
+			"no platform profiles have been enabled\n");
+		return -EOPNOTSUPP;
+	}
+
+	return performance_mode_acpi_set(galaxybook,
+					 galaxybook->profile_performance_modes[profile]);
+}
+
+#define gb_pfmode(profile) galaxybook->profile_performance_modes[profile]
+
+static int galaxybook_performance_mode_profile_init(struct samsung_galaxybook *galaxybook)
+{
+	enum platform_profile_option profile;
+	struct sawb buf = {};
+	unsigned int i;
+	int err;
+
+	/* fetch supported performance mode values from ACPI method */
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_PERFORMANCE_MODE;
+	export_guid(buf.caid, &GB_PERFORMANCE_MODE_GUID);
+	buf.fncn = GB_FNCN_PERFORMANCE_MODE;
+	buf.subn = GB_SUBN_PERFORMANCE_MODE_LIST;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_PERFORMANCE_MODE,
+				     &buf, GB_SAWB_LEN_PERFORMANCE_MODE);
+	if (err) {
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to get supported performance modes, error %d\n", err);
+		return err;
+	}
+
+	/* set initial default profile performance mode mappings */
+	gb_pfmode(PLATFORM_PROFILE_LOW_POWER) = GB_PERFORMANCE_MODE_SILENT;
+	gb_pfmode(PLATFORM_PROFILE_QUIET) = GB_PERFORMANCE_MODE_QUIET;
+	gb_pfmode(PLATFORM_PROFILE_BALANCED) = GB_PERFORMANCE_MODE_OPTIMIZED_LEGACY;
+	gb_pfmode(PLATFORM_PROFILE_PERFORMANCE) = GB_PERFORMANCE_MODE_PERFORMANCE_LEGACY;
+	gb_pfmode(PLATFORM_PROFILE_LAST) = GB_PERFORMANCE_MODE_INVALID;
+
+	/*
+	 * Value returned in iob0 will have the number of supported performance
+	 * modes per device. The performance mode values will then be given as a
+	 * list after this (iob1-iobX). Loop through the supported values and
+	 * enable their mapped platform_profile choice, overriding "legacy"
+	 * values along the way if a non-legacy value exists.
+	 */
+	for (i = 1; i <= buf.iob0; i++) {
+		dev_dbg(&galaxybook->platform->dev,
+			"device supports performance mode 0x%x\n", buf.iob_values[i]);
+		err = get_performance_mode_profile(galaxybook, buf.iob_values[i], &profile);
+		if (err)
+			continue;
+		switch (buf.iob_values[i]) {
+		case GB_PERFORMANCE_MODE_OPTIMIZED:
+			/* override legacy Optimized value */
+			gb_pfmode(profile) = GB_PERFORMANCE_MODE_OPTIMIZED;
+			break;
+		case GB_PERFORMANCE_MODE_PERFORMANCE:
+			/* override legacy Performance value */
+			gb_pfmode(profile) = GB_PERFORMANCE_MODE_PERFORMANCE;
+			break;
+		case GB_PERFORMANCE_MODE_ULTRA:
+			/*
+			 * if Ultra is supported, downgrade performance to
+			 * balanced-performance
+			 */
+			if (test_bit(PLATFORM_PROFILE_PERFORMANCE,
+				     galaxybook->platform_profile_choices)) {
+				gb_pfmode(PLATFORM_PROFILE_BALANCED_PERFORMANCE) =
+					gb_pfmode(PLATFORM_PROFILE_PERFORMANCE);
+				set_bit(PLATFORM_PROFILE_BALANCED_PERFORMANCE,
+					galaxybook->platform_profile_choices);
+			}
+			/* override performance profile to use Ultra's value */
+			gb_pfmode(profile) = GB_PERFORMANCE_MODE_ULTRA;
+			break;
+		default:
+			break;
+		}
+		set_bit(profile, galaxybook->platform_profile_choices);
+	}
+
+	err = galaxybook_performance_mode_init(galaxybook);
+	if (err) {
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to initialize performance mode, error %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int galaxybook_platform_profile_init(struct samsung_galaxybook *galaxybook)
+{
+	struct device *ppdev;
+	int err;
+
+	err = galaxybook_performance_mode_profile_init(galaxybook);
+	if (err)
+		return 0;
+
+	galaxybook->has_performance_mode = true;
+
+	ppdev = devm_platform_profile_register(&galaxybook->platform->dev, DRIVER_NAME,
+					       galaxybook, &galaxybook_platform_profile_ops);
+	if (IS_ERR(ppdev))
+		return PTR_ERR(ppdev);
+
+	platform_profile_notify(ppdev);
+
+	return 0;
+}
+
+/*
+ * Firmware Attributes
+ */
+
+/* Power on lid open (device should power on when lid is opened) */
+
+static int power_on_lid_open_acpi_set(struct samsung_galaxybook *galaxybook, const bool value)
+{
+	struct sawb buf = {};
+
+	lockdep_assert_held(&galaxybook->fw_attr_lock);
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_POWER_MANAGEMENT;
+	buf.gunm = GB_GUNM_POWER_MANAGEMENT;
+	buf.guds[0] = GB_GUDS_POWER_ON_LID_OPEN;
+	buf.guds[1] = GB_GUDS_POWER_ON_LID_OPEN_SET;
+	buf.guds[2] = value ? 1 : 0;
+
+	return galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				      &buf, GB_SAWB_LEN_SETTINGS);
+}
+
+static int power_on_lid_open_acpi_get(struct samsung_galaxybook *galaxybook, bool *value)
+{
+	struct sawb buf = {};
+	int err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_POWER_MANAGEMENT;
+	buf.gunm = GB_GUNM_POWER_MANAGEMENT;
+	buf.guds[0] = GB_GUDS_POWER_ON_LID_OPEN;
+	buf.guds[1] = GB_GUDS_POWER_ON_LID_OPEN_GET;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				     &buf, GB_SAWB_LEN_SETTINGS);
+	if (err)
+		return err;
+
+	*value = buf.guds[1];
+
+	return 0;
+}
+
+/* USB Charging (USB ports can provide power when device is powered off) */
+
+static int usb_charging_acpi_set(struct samsung_galaxybook *galaxybook, const bool value)
+{
+	struct sawb buf = {};
+
+	lockdep_assert_held(&galaxybook->fw_attr_lock);
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_USB_CHARGING_SET;
+	buf.gunm = value ? GB_GUNM_USB_CHARGING_ON : GB_GUNM_USB_CHARGING_OFF;
+
+	return galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				      &buf, GB_SAWB_LEN_SETTINGS);
+}
+
+static int usb_charging_acpi_get(struct samsung_galaxybook *galaxybook, bool *value)
+{
+	struct sawb buf = {};
+	int err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_USB_CHARGING_GET;
+	buf.gunm = GB_GUNM_USB_CHARGING_GET;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				     &buf, GB_SAWB_LEN_SETTINGS);
+	if (err)
+		return err;
+
+	*value = buf.gunm == 1;
+
+	return 0;
+}
+
+/* Block recording (blocks access to camera and microphone) */
+
+static int block_recording_acpi_set(struct samsung_galaxybook *galaxybook, const bool value)
+{
+	struct sawb buf = {};
+	int err;
+
+	lockdep_assert_held(&galaxybook->fw_attr_lock);
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_BLOCK_RECORDING;
+	buf.gunm = GB_GUNM_SET;
+	buf.guds[0] = value ? GB_BLOCK_RECORDING_ON : GB_BLOCK_RECORDING_OFF;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				     &buf, GB_SAWB_LEN_SETTINGS);
+	if (err)
+		return err;
+
+	input_report_switch(galaxybook->camera_lens_cover_switch,
+			    SW_CAMERA_LENS_COVER, value ? 1 : 0);
+	input_sync(galaxybook->camera_lens_cover_switch);
+
+	return 0;
+}
+
+static int block_recording_acpi_get(struct samsung_galaxybook *galaxybook, bool *value)
+{
+	struct sawb buf = {};
+	int err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_BLOCK_RECORDING;
+	buf.gunm = GB_GUNM_GET;
+
+	err = galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				     &buf, GB_SAWB_LEN_SETTINGS);
+	if (err)
+		return err;
+
+	*value = buf.gunm == GB_BLOCK_RECORDING_ON;
+
+	return 0;
+}
+
+static int galaxybook_block_recording_init(struct samsung_galaxybook *galaxybook)
+{
+	bool value;
+	int err;
+
+	err = galaxybook_enable_acpi_feature(galaxybook, GB_SASB_BLOCK_RECORDING);
+	if (err) {
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to initialize block_recording, error %d\n", err);
+		return 0;
+	}
+
+	guard(mutex)(&galaxybook->fw_attr_lock);
+
+	err = block_recording_acpi_get(galaxybook, &value);
+	if (err) {
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to get initial block_recording state, error %d\n", err);
+		return 0;
+	}
+
+	galaxybook->camera_lens_cover_switch =
+		devm_input_allocate_device(&galaxybook->platform->dev);
+	if (!galaxybook->camera_lens_cover_switch)
+		return -ENOMEM;
+
+	galaxybook->camera_lens_cover_switch->name = "Samsung Galaxy Book Camera Lens Cover";
+	galaxybook->camera_lens_cover_switch->phys = DRIVER_NAME "/input0";
+	galaxybook->camera_lens_cover_switch->id.bustype = BUS_HOST;
+
+	input_set_capability(galaxybook->camera_lens_cover_switch, EV_SW, SW_CAMERA_LENS_COVER);
+
+	err = input_register_device(galaxybook->camera_lens_cover_switch);
+	if (err)
+		return err;
+
+	input_report_switch(galaxybook->camera_lens_cover_switch,
+			    SW_CAMERA_LENS_COVER, value ? 1 : 0);
+	input_sync(galaxybook->camera_lens_cover_switch);
+
+	galaxybook->has_block_recording = true;
+
+	return 0;
+}
+
+/* Firmware Attributes setup */
+
+static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "enumeration\n");
+}
+
+static struct kobj_attribute fw_attr_type = __ATTR_RO(type);
+
+static ssize_t default_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "0\n");
+}
+
+static struct kobj_attribute fw_attr_default_value = __ATTR_RO(default_value);
+
+static ssize_t possible_values_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "0;1\n");
+}
+
+static struct kobj_attribute fw_attr_possible_values = __ATTR_RO(possible_values);
+
+static ssize_t display_name_language_code_show(struct kobject *kobj, struct kobj_attribute *attr,
+					       char *buf)
+{
+	return sysfs_emit(buf, "%s\n", GB_ATTR_LANGUAGE_CODE);
+}
+
+static struct kobj_attribute fw_attr_display_name_language_code =
+	__ATTR_RO(display_name_language_code);
+
+static ssize_t display_name_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	struct galaxybook_fw_attr *fw_attr =
+		container_of(attr, struct galaxybook_fw_attr, display_name);
+
+	return sysfs_emit(buf, "%s\n", galaxybook_fw_attr_desc[fw_attr->fw_attr_id]);
+}
+
+static ssize_t current_value_store(struct kobject *kobj, struct kobj_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct galaxybook_fw_attr *fw_attr =
+		container_of(attr, struct galaxybook_fw_attr, current_value);
+	struct samsung_galaxybook *galaxybook = fw_attr->galaxybook;
+	bool value;
+	int err;
+
+	if (!count)
+		return -EINVAL;
+
+	err = kstrtobool(buf, &value);
+	if (err)
+		return err;
+
+	guard(mutex)(&galaxybook->fw_attr_lock);
+
+	err = fw_attr->set_value(galaxybook, value);
+	if (err)
+		return err;
+
+	return count;
+}
+
+static ssize_t current_value_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
+{
+	struct galaxybook_fw_attr *fw_attr =
+		container_of(attr, struct galaxybook_fw_attr, current_value);
+	bool value;
+	int err;
+
+	err = fw_attr->get_value(fw_attr->galaxybook, &value);
+	if (err)
+		return err;
+
+	return sysfs_emit(buf, "%u\n", value);
+}
+
+static void galaxybook_fw_attr_remove(void *data)
+{
+	struct galaxybook_fw_attr *fw_attr = data;
+	struct samsung_galaxybook *galaxybook = fw_attr->galaxybook;
+
+	sysfs_remove_group(&galaxybook->fw_attrs_kset->kobj, &fw_attr->attr_group);
+}
+
+#define NUM_FW_ATTR_ENUM_ATTRS  6
+
+static int galaxybook_fw_attr_init(struct samsung_galaxybook *galaxybook,
+				   const enum galaxybook_fw_attr_id fw_attr_id,
+				   int (*get_value)(struct samsung_galaxybook *galaxybook,
+						    bool *value),
+				   int (*set_value)(struct samsung_galaxybook *galaxybook,
+						    const bool value))
+{
+	struct galaxybook_fw_attr *fw_attr;
+	struct attribute **attrs;
+	int err;
+
+	fw_attr = devm_kzalloc(&galaxybook->platform->dev, sizeof(*fw_attr), GFP_KERNEL);
+	if (!fw_attr)
+		return -ENOMEM;
+
+	attrs = devm_kcalloc(&galaxybook->platform->dev, NUM_FW_ATTR_ENUM_ATTRS + 1,
+			     sizeof(*attrs), GFP_KERNEL);
+	if (!attrs)
+		return -ENOMEM;
+
+	attrs[0] = &fw_attr_type.attr;
+	attrs[1] = &fw_attr_default_value.attr;
+	attrs[2] = &fw_attr_possible_values.attr;
+	attrs[3] = &fw_attr_display_name_language_code.attr;
+
+	sysfs_attr_init(&fw_attr.display_name);
+	fw_attr->display_name.attr.name = "display_name";
+	fw_attr->display_name.attr.mode = 0444;
+	fw_attr->display_name.show = display_name_show;
+	attrs[4] = &fw_attr->display_name.attr;
+
+	sysfs_attr_init(&fw_attr.current_value);
+	fw_attr->current_value.attr.name = "current_value";
+	fw_attr->current_value.attr.mode = 0644;
+	fw_attr->current_value.show = current_value_show;
+	fw_attr->current_value.store = current_value_store;
+	attrs[5] = &fw_attr->current_value.attr;
+
+	attrs[6] = NULL;
+
+	fw_attr->galaxybook = galaxybook;
+	fw_attr->fw_attr_id = fw_attr_id;
+	fw_attr->attr_group.name = galaxybook_fw_attr_name[fw_attr_id];
+	fw_attr->attr_group.attrs = attrs;
+	fw_attr->get_value = get_value;
+	fw_attr->set_value = set_value;
+
+	err = sysfs_create_group(&galaxybook->fw_attrs_kset->kobj, &fw_attr->attr_group);
+	if (err)
+		return err;
+
+	return devm_add_action_or_reset(&galaxybook->platform->dev,
+					galaxybook_fw_attr_remove, fw_attr);
+}
+
+static void galaxybook_kset_unregister(void *data)
+{
+	struct kset *kset = data;
+
+	kset_unregister(kset);
+}
+
+static void galaxybook_fw_attrs_dev_unregister(void *data)
+{
+	struct device *fw_attrs_dev = data;
+
+	device_unregister(fw_attrs_dev);
+}
+
+static int galaxybook_fw_attrs_init(struct samsung_galaxybook *galaxybook)
+{
+	bool value;
+	int err;
+
+	err = devm_mutex_init(&galaxybook->platform->dev, &galaxybook->fw_attr_lock);
+	if (err)
+		return err;
+
+	galaxybook->fw_attrs_dev = device_create(&firmware_attributes_class, NULL, MKDEV(0, 0),
+						 NULL, "%s", DRIVER_NAME);
+	if (IS_ERR(galaxybook->fw_attrs_dev)) {
+		err = PTR_ERR(galaxybook->fw_attrs_dev);
+		return err;
+	}
+	err = devm_add_action_or_reset(&galaxybook->platform->dev,
+				       galaxybook_fw_attrs_dev_unregister,
+				       galaxybook->fw_attrs_dev);
+	if (err)
+		return err;
+
+	galaxybook->fw_attrs_kset = kset_create_and_add("attributes", NULL,
+							&galaxybook->fw_attrs_dev->kobj);
+	if (!galaxybook->fw_attrs_kset)
+		return -ENOMEM;
+	err = devm_add_action_or_reset(&galaxybook->platform->dev,
+				       galaxybook_kset_unregister, galaxybook->fw_attrs_kset);
+	if (err)
+		return err;
+
+	err = power_on_lid_open_acpi_get(galaxybook, &value);
+	if (!err) {
+		err = galaxybook_fw_attr_init(galaxybook,
+					      GB_ATTR_POWER_ON_LID_OPEN,
+					      &power_on_lid_open_acpi_get,
+					      &power_on_lid_open_acpi_set);
+		if (err)
+			return err;
+	}
+
+	err = usb_charging_acpi_get(galaxybook, &value);
+	if (!err) {
+		err = galaxybook_fw_attr_init(galaxybook,
+					      GB_ATTR_USB_CHARGING,
+					      &usb_charging_acpi_get,
+					      &usb_charging_acpi_set);
+		if (err)
+			return err;
+	}
+
+	/* block_recording requires an additional init before it can be used */
+	err = galaxybook_block_recording_init(galaxybook);
+	if (err)
+		return err;
+	if (!galaxybook->has_block_recording)
+		return 0;
+
+	err = block_recording_acpi_get(galaxybook, &value);
+	if (err) {
+		galaxybook->has_block_recording = false;
+		return 0;
+	}
+
+	return galaxybook_fw_attr_init(galaxybook,
+				       GB_ATTR_BLOCK_RECORDING,
+				       &block_recording_acpi_get,
+				       &block_recording_acpi_set);
+}
+
+/*
+ * Hotkeys and notifications
+ */
+
+static void galaxybook_kbd_backlight_hotkey_work(struct work_struct *work)
+{
+	struct samsung_galaxybook *galaxybook =
+		from_work(galaxybook, work, kbd_backlight_hotkey_work);
+	int brightness;
+	int err;
+
+	guard(mutex)(&galaxybook->kbd_backlight_lock);
+
+	brightness = galaxybook->kbd_backlight.brightness;
+	if (brightness < galaxybook->kbd_backlight.max_brightness)
+		brightness++;
+	else
+		brightness = 0;
+
+	err = led_set_brightness_sync(&galaxybook->kbd_backlight, brightness);
+	if (err) {
+		dev_err(&galaxybook->platform->dev,
+			"failed to set kbd_backlight brightness, error %d\n", err);
+		return;
+	}
+
+	led_classdev_notify_brightness_hw_changed(&galaxybook->kbd_backlight, brightness);
+}
+
+static void galaxybook_block_recording_hotkey_work(struct work_struct *work)
+{
+	struct samsung_galaxybook *galaxybook =
+		from_work(galaxybook, work, block_recording_hotkey_work);
+	bool value;
+	int err;
+
+	guard(mutex)(&galaxybook->fw_attr_lock);
+
+	err = block_recording_acpi_get(galaxybook, &value);
+	if (err) {
+		dev_err(&galaxybook->platform->dev,
+			"failed to get block_recording, error %d\n", err);
+		return;
+	}
+
+	err = block_recording_acpi_set(galaxybook, !value);
+	if (err)
+		dev_err(&galaxybook->platform->dev,
+			"failed to set block_recording, error %d\n", err);
+}
+
+static bool galaxybook_i8042_filter(unsigned char data, unsigned char str, struct serio *port,
+				    void *context)
+{
+	struct samsung_galaxybook *galaxybook = context;
+	static bool extended;
+
+	if (str & I8042_STR_AUXDATA)
+		return false;
+
+	if (data == 0xe0) {
+		extended = true;
+		return true;
+	} else if (extended) {
+		extended = false;
+		switch (data) {
+		case GB_KEY_KBD_BACKLIGHT_KEYDOWN:
+			return true;
+		case GB_KEY_KBD_BACKLIGHT_KEYUP:
+			if (galaxybook->has_kbd_backlight)
+				schedule_work(&galaxybook->kbd_backlight_hotkey_work);
+			return true;
+
+		case GB_KEY_BLOCK_RECORDING_KEYDOWN:
+			return true;
+		case GB_KEY_BLOCK_RECORDING_KEYUP:
+			if (galaxybook->has_block_recording)
+				schedule_work(&galaxybook->block_recording_hotkey_work);
+			return true;
+
+		/* battery notification already sent to battery + SCAI device */
+		case GB_KEY_BATTERY_NOTIFY_KEYUP:
+		case GB_KEY_BATTERY_NOTIFY_KEYDOWN:
+			return true;
+
+		default:
+			/*
+			 * Report the previously filtered e0 before continuing
+			 * with the next non-filtered byte.
+			 */
+			serio_interrupt(port, 0xe0, 0);
+			return false;
+		}
+	}
+
+	return false;
+}
+
+static void galaxybook_i8042_filter_remove(void *data)
+{
+	struct samsung_galaxybook *galaxybook = data;
+
+	i8042_remove_filter(galaxybook_i8042_filter);
+	cancel_work_sync(&galaxybook->kbd_backlight_hotkey_work);
+	cancel_work_sync(&galaxybook->block_recording_hotkey_work);
+}
+
+static int galaxybook_i8042_filter_install(struct samsung_galaxybook *galaxybook)
+{
+	int err;
+
+	if (!galaxybook->has_kbd_backlight && !galaxybook->has_block_recording)
+		return 0;
+
+	INIT_WORK(&galaxybook->kbd_backlight_hotkey_work,
+		  galaxybook_kbd_backlight_hotkey_work);
+	INIT_WORK(&galaxybook->block_recording_hotkey_work,
+		  galaxybook_block_recording_hotkey_work);
+
+	err = i8042_install_filter(galaxybook_i8042_filter, galaxybook);
+	if (err)
+		return err;
+
+	return devm_add_action_or_reset(&galaxybook->platform->dev,
+					galaxybook_i8042_filter_remove, galaxybook);
+}
+
+/*
+ * ACPI device setup
+ */
+
+static void galaxybook_acpi_notify(acpi_handle handle, u32 event, void *data)
+{
+	struct samsung_galaxybook *galaxybook = data;
+
+	switch (event) {
+	case GB_ACPI_NOTIFY_BATTERY_STATE_CHANGED:
+	case GB_ACPI_NOTIFY_DEVICE_ON_TABLE:
+	case GB_ACPI_NOTIFY_DEVICE_OFF_TABLE:
+		break;
+	case GB_ACPI_NOTIFY_HOTKEY_PERFORMANCE_MODE:
+		if (galaxybook->has_performance_mode)
+			platform_profile_cycle();
+		break;
+	default:
+		dev_warn(&galaxybook->platform->dev,
+			 "unknown ACPI notification event: 0x%x\n", event);
+	}
+
+	acpi_bus_generate_netlink_event(DRIVER_NAME, dev_name(&galaxybook->platform->dev),
+					event, 1);
+}
+
+static int galaxybook_enable_acpi_notify(struct samsung_galaxybook *galaxybook)
+{
+	struct sawb buf = {};
+	int err;
+
+	err = galaxybook_enable_acpi_feature(galaxybook, GB_SASB_NOTIFICATIONS);
+	if (err)
+		return err;
+
+	buf.safn = GB_SAFN;
+	buf.sasb = GB_SASB_NOTIFICATIONS;
+	buf.gunm = GB_GUNM_ACPI_NOTIFY_ENABLE;
+	buf.guds[0] = GB_GUDS_ACPI_NOTIFY_ENABLE;
+
+	return galaxybook_acpi_method(galaxybook, GB_ACPI_METHOD_SETTINGS,
+				      &buf, GB_SAWB_LEN_SETTINGS);
+}
+
+static void galaxybook_acpi_remove_notify_handler(void *data)
+{
+	struct samsung_galaxybook *galaxybook = data;
+
+	acpi_remove_notify_handler(galaxybook->acpi->handle, ACPI_ALL_NOTIFY,
+				   galaxybook_acpi_notify);
+}
+
+static void galaxybook_acpi_disable(void *data)
+{
+	struct samsung_galaxybook *galaxybook = data;
+
+	acpi_execute_simple_method(galaxybook->acpi->handle,
+				   GB_ACPI_METHOD_ENABLE, GB_ACPI_METHOD_ENABLE_OFF);
+}
+
+static int galaxybook_acpi_init(struct samsung_galaxybook *galaxybook)
+{
+	acpi_status status;
+	int err;
+
+	status = acpi_execute_simple_method(galaxybook->acpi->handle, GB_ACPI_METHOD_ENABLE,
+					    GB_ACPI_METHOD_ENABLE_ON);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+	err = devm_add_action_or_reset(&galaxybook->platform->dev,
+				       galaxybook_acpi_disable, galaxybook);
+	if (err)
+		return err;
+
+	status = acpi_install_notify_handler(galaxybook->acpi->handle, ACPI_ALL_NOTIFY,
+					     galaxybook_acpi_notify, galaxybook);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+	err = devm_add_action_or_reset(&galaxybook->platform->dev,
+				       galaxybook_acpi_remove_notify_handler, galaxybook);
+	if (err)
+		return err;
+
+	err = galaxybook_enable_acpi_notify(galaxybook);
+	if (err)
+		dev_dbg(&galaxybook->platform->dev, "failed to enable ACPI notifications; "
+			"some hotkeys will not be supported\n");
+
+	err = galaxybook_enable_acpi_feature(galaxybook, GB_SASB_POWER_MANAGEMENT);
+	if (err)
+		dev_dbg(&galaxybook->platform->dev,
+			"failed to initialize ACPI power management features; "
+			"many features of this driver will not be available\n");
+
+	return 0;
+}
+
+/*
+ * Platform driver
+ */
+
+static int galaxybook_probe(struct platform_device *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	struct samsung_galaxybook *galaxybook;
+	int err;
+
+	if (!adev)
+		return -ENODEV;
+
+	galaxybook = devm_kzalloc(&pdev->dev, sizeof(*galaxybook), GFP_KERNEL);
+	if (!galaxybook)
+		return -ENOMEM;
+
+	galaxybook->platform = pdev;
+	galaxybook->acpi = adev;
+	galaxybook->has_kbd_backlight = false;
+	galaxybook->has_block_recording = false;
+	galaxybook->has_performance_mode = false;
+
+	err = galaxybook_acpi_init(galaxybook);
+	if (err)
+		return dev_err_probe(&galaxybook->platform->dev, err,
+				     "failed to initialize ACPI device\n");
+
+	err = galaxybook_platform_profile_init(galaxybook);
+	if (err)
+		return dev_err_probe(&galaxybook->platform->dev, err,
+				     "failed to initialize platform profile\n");
+
+	err = galaxybook_battery_threshold_init(galaxybook);
+	if (err)
+		return dev_err_probe(&galaxybook->platform->dev, err,
+				     "failed to initialize battery threshold\n");
+
+	err = galaxybook_kbd_backlight_init(galaxybook);
+	if (err)
+		return dev_err_probe(&galaxybook->platform->dev, err,
+				     "failed to initialize kbd_backlight\n");
+
+	err = galaxybook_fw_attrs_init(galaxybook);
+	if (err)
+		return dev_err_probe(&galaxybook->platform->dev, err,
+				     "failed to initialize firmware-attributes\n");
+
+	err = galaxybook_i8042_filter_install(galaxybook);
+	if (err)
+		return dev_err_probe(&galaxybook->platform->dev, err,
+				     "failed to initialize i8042_filter\n");
+
+	return 0;
+}
+
+static const struct acpi_device_id galaxybook_device_ids[] = {
+	{ "SAM0427" },
+	{ "SAM0428" },
+	{ "SAM0429" },
+	{ "SAM0430" },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, galaxybook_device_ids);
+
+static struct platform_driver galaxybook_platform_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.acpi_match_table = galaxybook_device_ids,
+	},
+	.probe = galaxybook_probe,
+};
+module_platform_driver(galaxybook_platform_driver);
+
+MODULE_AUTHOR("Joshua Grisham <josh@joshuagrisham.com>");
+MODULE_DESCRIPTION("Samsung Galaxy Book driver");
+MODULE_LICENSE("GPL");