Add software nodes for the HID sensor collection and the UCM UCSI HID
client to the Surface Pro 8. In contrast to the type-cover devices,
these devices are directly attached to the SAM controller, without any
hub.
This enables support for HID-based sensors, including the ones used for
automatic screen rotation, on the Surface Pro 8.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220810144117.493710-4-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Move helper functions for client device registration to the core module.
This simplifies addition of future DT/OF support and also allows us to
split out the device hub drivers into their own module.
At the same time, also improve device node validation a bit by not
silently skipping devices with invalid device UID specifiers. Further,
ensure proper lifetime management for the firmware/software nodes
associated with the added devices.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220624205800.1355621-2-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Add a driver providing a tablet-mode switch input device for Microsoft
Surface devices using the Surface Aggregator KIP subsystem (to manage
detachable peripherals) or POS subsystem (to obtain device posture
information).
The KIP (full name unknown, abbreviation found through reverse
engineering) subsystem is used on the Surface Pro 8 and Surface Pro X to
manage the keyboard cover. Among other things, it provides information
on the positioning (posture) of the cover (closed, laptop-style,
detached, folded-back, ...), which can be used to implement an input
device providing the SW_TABLET_MODE event. Similarly, the POS (posture
information) subsystem provides such information on the Surface Laptop
Studio, with the difference being that the keyboard is not detachable.
As implementing the tablet-mode switch for both subsystems is largely
similar, the driver proposed in this commit, in large, acts as a generic
tablet mode switch driver framework for the Surface Aggregator Module.
Specific implementations using this framework are provided for the KIP
and POS subsystems, adding tablet-mode switch support to the
aforementioned devices.
A few more notes on the Surface Laptop Studio:
A peculiarity of the Surface Laptop Studio is its "slate/tent" mode
(symbolized: user> _/\). In this mode, the screen covers the keyboard
but leaves the touchpad exposed. This is essentially a mode in-between
tablet and laptop, and it is debatable whether tablet-mode should be
enabled in this mode. We therefore let the user decide this via a module
parameter.
In particular, tablet-mode may bring up the on-screen touch keyboard
more easily, which would be desirable in this mode. However, some
user-space software currently also decides to disable keyboard and, more
importantly, touchpad input, while the touchpad is still accessible in
the "slate/tent" mode. Furthermore, this mode shares its identifier with
"slate/flipped" mode where the screen is flipped 180° and the keyboard
points away from the user (symbolized: user> /_). In this mode we would
like to enable auto-rotation, something that user-space software may
only do when tablet-mode is enabled. We therefore default to the
slate-mode enabling the tablet-mode switch.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220624183642.910893-3-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Add support for the detachable keyboard cover on the Surface Pro 8.
The keyboard cover on the Surface Pro 8 is, unlike the keyboard covers
of earlier Surface Pro generations, handled via the Surface System
Aggregator Module (SSAM). The keyboard and touchpad (as well as other
HID input devices) of this cover are standard SSAM HID client devices
(just like keyboard and touchpad on e.g. the Surface Laptop 3 and 4),
however, some care needs to be taken as they can be physically detached
(similarly to the Surface Book 3). Specifically, the respective SSAM
client devices need to be removed when the keyboard cover has been
detached and (re-)initialized when the keyboard cover has been
(re-)attached.
On the Surface Pro 8, detachment of the keyboard cover (and by extension
its devices) is managed via the KIP subsystem. Therefore, said devices
need to be registered under the KIP device hub, which in turn will
remove and re-create/re-initialize those devices as needed.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220527023447.2460025-13-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Add a Surface System Aggregator Module (SSAM) client device hub for
hot-removable devices managed via the KIP subsystem.
The KIP subsystem (full name unknown, abbreviation has been obtained
through reverse engineering) is a subsystem that manages hot-removable
SSAM client devices. Specifically, it manages HID input devices
contained in the detachable keyboard cover of the Surface Pro 8 and
Surface Pro X.
The KIP subsystem handles a single group of devices (e.g. all devices
contained in the keyboard cover) and cannot handle devices individually.
Thus we model it as a client device hub, which (hot-)removes all devices
contained under it once removal of the hub (e.g. keyboard cover) has
been detected and (re-)adds all devices once the physical hub device has
been (re-)attached. To do this, use the previously generified SSAM
subsystem hub framework.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220527023447.2460025-12-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The Surface System Aggregator Module (SSAM) has multiple subsystems that
can manage detachable devices. At the moment, we only support the "base"
(BAS/0x11) subsystem, which is used on the Surface Book 3 to manage
devices (including keyboard, touchpad, and secondary battery) connected
to the base of the device.
The Surface Pro 8 has a new type-cover with keyboard and touchpad, which
is managed via the KIP/0x0e subsystem. The general procedure is the
same, but with slightly different events and setup. To make
implementation of the KIP hub easier and prevent duplication, generify
the parts of the base hub that we can use for the KIP hub (or any
potential future subsystem hubs).
This also switches over to use the newly introduced "hot-remove"
functionality, which should prevent communication issues when devices
have been detached.
Lastly, also drop the undocumented and unused sysfs "state" attribute of
the base hub. It has at best been useful for debugging.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220527023447.2460025-10-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
When SSAM client devices have been (physically) hot-removed,
communication attempts with those devices may fail and time out. This
can even extend to event notifiers, due to which timeouts may occur
during device removal, slowing down that process.
Add a parameter to the notifier unregister function that allows skipping
communication with the EC to prevent this. Furthermore, add wrappers for
registering and unregistering notifiers belonging to SSAM client devices
that automatically check if the device has been marked as hot-removed
and communication should be avoided.
Note that non-SSAM client devices can generally not be hot-removed, so
also add a convenience wrapper for those, defaulting to allow
communication.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220527023447.2460025-4-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
When building the Surface Aggregator Module (SAM) core, registry, and
other SAM client drivers as builtin modules (=y), proper initialization
order is not guaranteed. Due to this, client driver registration
(triggered by device registration in the registry) races against bus
initialization in the core.
If any attempt is made at registering the device driver before the bus
has been initialized (i.e. if bus initialization fails this race) driver
registration will fail with a message similar to:
Driver surface_battery was unable to register with bus_type surface_aggregator because the bus was not initialized
Switch from module_init() to subsys_initcall() to resolve this issue.
Note that the serdev subsystem uses postcore_initcall() so we are still
able to safely register the serdev device driver for the core.
Fixes: c167b9c7e3 ("platform/surface: Add Surface Aggregator subsystem")
Reported-by: Blaž Hrastnik <blaz@mxxn.io>
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20220429195738.535751-1-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The battery on the 2nd hand Surface 3 which I recently bought appears to
not have a serial number programmed in. This results in any I2C reads from
the registers containing the serial number failing with an I2C NACK.
This was causing mshw0011_bix() to fail causing the battery readings to
not work at all.
Ignore EREMOTEIO (I2C NACK) errors when retrieving the serial number and
continue with an empty serial number to fix this.
Fixes: b1f81b496b ("platform/x86: surface3_power: MSHW0011 rev-eng implementation")
BugLink: https://github.com/linux-surface/linux-surface/issues/608
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220224101848.7219-1-hdegoede@redhat.com
