The Surface ACPI Notify (SAN) device provides an ACPI interface to the
Surface Aggregator EC, specifically the Surface Serial Hub interface.
This interface allows EC requests to be made from ACPI code and can
convert a subset of EC events back to ACPI notifications.
Specifically, this interface provides a GenericSerialBus operation
region ACPI code can execute a request by writing the request command
data and payload to this operation region and reading back the
corresponding response via a write-then-read operation. Furthermore,
this interface provides a _DSM method to be called when certain events
from the EC have been received, essentially turning them into ACPI
notifications.
The driver provided in this commit essentially takes care of translating
the request data written to the operation region, executing the request,
waiting for it to finish, and finally writing and translating back the
response (if the request has one). Furthermore, this driver takes care
of enabling the events handled via ACPI _DSM calls. Lastly, this driver
also exposes an interface providing discrete GPU (dGPU) power-on
notifications on the Surface Book 2, which are also received via the
operation region interface (but not handled by the SAN driver directly),
making them accessible to other drivers (such as a dGPU hot-plug driver
that may be added later on).
On 5th and 6th generation Surface devices (Surface Pro 5/2017, Pro 6,
Book 2, Laptop 1 and 2), the SAN interface provides full battery and
thermal subsystem access, as well as other EC based functionality. On
those models, battery and thermal sensor devices are implemented as
standard ACPI devices of that type, however, forward ACPI calls to the
corresponding Surface Aggregator EC request via the SAN interface and
receive corresponding notifications (e.g. battery information change)
from it. This interface is therefore required to provide said
functionality on those devices.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201221183959.1186143-10-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Add a misc-device providing user-space access to the Surface Aggregator
EC, mainly intended for debugging, testing, and reverse-engineering.
This interface gives user-space applications the ability to send
requests to the EC and receive the corresponding responses.
The device-file is managed by a pseudo platform-device and corresponding
driver to avoid dependence on the dedicated bus, allowing it to be
loaded in a minimal configuration.
A python library and scripts to access this device can be found at [1].
[1]: https://github.com/linux-surface/surface-aggregator-module/tree/master/scripts/ssam
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20201221183959.1186143-9-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Add Surface System Aggregator Module core and Surface Serial Hub driver,
required for the embedded controller found on Microsoft Surface devices.
The Surface System Aggregator Module (SSAM, SAM or Surface Aggregator)
is an embedded controller (EC) found on 4th and later generation
Microsoft Surface devices, with the exception of the Surface Go series.
This EC provides various functionality, depending on the device in
question. This can include battery status and thermal reporting (5th and
later generations), but also HID keyboard (6th+) and touchpad input
(7th+) on Surface Laptop and Surface Book 3 series devices.
This patch provides the basic necessities for communication with the SAM
EC on 5th and later generation devices. On these devices, the EC
provides an interface that acts as serial device, called the Surface
Serial Hub (SSH). 4th generation devices, on which the EC interface is
provided via an HID-over-I2C device, are not supported by this patch.
Specifically, this patch adds a driver for the SSH device (device HID
MSHW0084 in ACPI), as well as a controller structure and associated API.
This represents the functional core of the Surface Aggregator kernel
subsystem, introduced with this patch, and will be expanded upon in
subsequent commits.
The SSH driver acts as the main attachment point for this subsystem and
sets-up and manages the controller structure. The controller in turn
provides a basic communication interface, allowing to send requests from
host to EC and receiving the corresponding responses, as well as
managing and receiving events, sent from EC to host. It is structured
into multiple layers, with the top layer presenting the API used by
other kernel drivers and the lower layers modeled after the serial
protocol used for communication.
Said other drivers are then responsible for providing the (Surface model
specific) functionality accessible through the EC (e.g. battery status
reporting, thermal information, ...) via said controller structure and
API, and will be added in future commits.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20201221183959.1186143-2-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
All Microsoft Surface platform-specific device drivers depend on ACPI,
but the gatekeeper symbol SURFACE_PLATFORMS does not. Hence when the
user is configuring a kernel without ACPI support, he is still asked
about Microsoft Surface drivers, even though this question is
irrelevant.
Fix this by moving the dependency on ACPI from the individual driver
symbols to SURFACE_PLATFORMS.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20201216133752.1321978-1-geert@linux-m68k.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Conventionally, wake-up events for a specific device, in our case the
lid device, are managed via the ACPI _PRW field. While this does not
seem strictly necessary based on ACPI spec, the kernel disables GPE
wakeups to avoid non-wakeup interrupts preventing suspend by default and
only enables GPEs associated via the _PRW field with a wake-up capable
device. This behavior has been introduced in commit f941d3e41d ("ACPI:
EC / PM: Disable non-wakeup GPEs for suspend-to-idle") and is described
in more detail in its commit message.
Unfortunately, on MS Surface devices, there is no _PRW field present on
the lid device, thus no GPE is associated with it, and therefore the GPE
responsible for sending the status-change notification to the lid gets
disabled during suspend, making it impossible to wake the device via the
lid.
This patch introduces a pseudo-device and respective driver which, based
on some DMI matching, marks the corresponding GPE of the lid device for
wake and enables it during suspend. The behavior of this driver models
the behavior of the ACPI/PM core for normal wakeup GPEs, properly
declared via the _PRW field.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20201028105427.1593764-1-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Move the Surface Pro 3 Button driver from platform/x86 to the newly
created platform/surface directory.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Chen Yu <yu.c.chen@intel.com>
Link: https://lore.kernel.org/r/20201009141128.683254-6-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Move the Surface 3 Power operation region driver from platform/x86 to
the newly created platform/surface directory.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201009141128.683254-5-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Move the Surface 3 Button driver from platform/x86 to the newly created
platform/surface directory.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201009141128.683254-4-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Move the Surface 3 WMI driver from platform/x86 to the newly created
platform/surface directory.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201009141128.683254-3-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
It may make sense to split the Microsoft Surface hardware platform
drivers out to a separate subdirectory, since some of it may be shared
between ARM and x86 in the future (regarding devices like the Surface
Pro X).
Further, newer Surface devices will require additional platform drivers
for fundamental support (mostly regarding their embedded controller),
which may also warrant this split from a size perspective.
This commit introduces a new platform/surface subdirectory for the
Surface device family, with subsequent commits moving existing Surface
drivers over from platform/x86.
A new MAINTAINERS entry is added for this directory. Patches to files in
this directory will be taken up by the platform-drivers-x86 team (i.e.
Hans de Goede and Mark Gross) after they have been reviewed by
Maximilian Luz.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20201009141128.683254-2-luzmaximilian@gmail.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
