| .. SPDX-License-Identifier: GPL-2.0+ |
| |
| .. |san_client_link| replace:: :c:func:`san_client_link` |
| .. |san_dgpu_notifier_register| replace:: :c:func:`san_dgpu_notifier_register` |
| .. |san_dgpu_notifier_unregister| replace:: :c:func:`san_dgpu_notifier_unregister` |
| |
| =================== |
| Surface ACPI Notify |
| =================== |
| |
| The Surface ACPI Notify (SAN) device provides the bridge between ACPI and |
| SAM controller. Specifically, ACPI code can execute requests and handle |
| battery and thermal events via this interface. In addition to this, events |
| relating to the discrete GPU (dGPU) of the Surface Book 2 can be sent from |
| ACPI code (note: the Surface Book 3 uses a different method for this). The |
| only currently known event sent via this interface is a dGPU power-on |
| notification. While this driver handles the former part internally, it only |
| relays the dGPU events to any other driver interested via its public API and |
| does not handle them. |
| |
| The public interface of this driver is split into two parts: Client |
| registration and notifier-block registration. |
| |
| A client to the SAN interface can be linked as consumer to the SAN device |
| via |san_client_link|. This can be used to ensure that the a client |
| receiving dGPU events does not miss any events due to the SAN interface not |
| being set up as this forces the client driver to unbind once the SAN driver |
| is unbound. |
| |
| Notifier-blocks can be registered by any device for as long as the module is |
| loaded, regardless of being linked as client or not. Registration is done |
| with |san_dgpu_notifier_register|. If the notifier is not needed any more, it |
| should be unregistered via |san_dgpu_notifier_unregister|. |
| |
| Consult the API documentation below for more details. |
| |
| |
| API Documentation |
| ================= |
| |
| .. kernel-doc:: include/linux/surface_acpi_notify.h |
| |
| .. kernel-doc:: drivers/platform/surface/surface_acpi_notify.c |
| :export: |
