Commit 167f77f7 authored by Maximilian Luz's avatar Maximilian Luz Committed by Sebastian Reichel
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power: supply: Add battery driver for Surface Aggregator Module 



On newer Microsoft Surface models (specifically 7th-generation, i.e.
Surface Pro 7, Surface Book 3, Surface Laptop 3, and Surface Laptop Go),
battery and AC status/information is no longer handled via standard ACPI
devices, but instead directly via the Surface System Aggregator Module
(SSAM), i.e. the embedded controller on those devices.

While on previous generation models, battery status is also handled via
SSAM, an ACPI shim was present to translate the standard ACPI battery
interface to SSAM requests. The SSAM interface itself, which is modeled
closely after the ACPI interface, has not changed.

This commit introduces a new SSAM client device driver to support
battery status/information via the aforementioned interface on said
Surface models. It is in parts based on the standard ACPI battery
driver.

Signed-off-by: default avatarMaximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent b6dc03fa

Documentation/ABI/testing/sysfs-class-power-surface

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What:		/sys/class/power_supply/<supply_name>/alarm

Date:		April 2021

KernelVersion:	5.13

Contact:	Maximilian Luz <luzmaximilian@gmail.com>

Description:

		Battery trip point. When the remaining battery capacity crosses this

		value in either direction, the system will be notified and if

		necessary woken.



		Set to zero to clear/disable.



		Access: Read, Write



		Valid values: In micro-Wh or micro-Ah, depending on the power unit

		of the battery

MAINTAINERS

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@@ -11861,6 +11861,13 @@ F: drivers/scsi/smartpqi/smartpqi*.[ch] 
F:	include/linux/cciss*.h

F:	include/uapi/linux/cciss*.h









MICROSOFT SURFACE BATTERY AND AC DRIVERS









M:	Maximilian Luz <luzmaximilian@gmail.com>









L:	linux-pm@vger.kernel.org









L:	platform-driver-x86@vger.kernel.org









S:	Maintained









F:	drivers/power/supply/surface_battery.c

















MICROSOFT SURFACE GPE LID SUPPORT DRIVER









M:	Maximilian Luz <luzmaximilian@gmail.com>









L:	platform-driver-x86@vger.kernel.org
































drivers/power/supply/Kconfig



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@@ -801,4 +801,20 @@ config BATTERY_ACER_A500







	help









	  Say Y to include support for Acer Iconia Tab A500 battery fuel gauge.



















config BATTERY_SURFACE









	tristate "Battery driver for 7th-generation Microsoft Surface devices"









	depends on SURFACE_AGGREGATOR_REGISTRY









	help









	  Driver for battery devices connected via/managed by the Surface System









	  Aggregator Module (SSAM).



















	  This driver provides battery-information and -status support for









	  Surface devices where said data is not exposed via the standard ACPI









	  devices. On those models (7th-generation), battery-information is









	  instead handled directly via SSAM client devices and this driver.



















	  Say M or Y here to include battery status support for 7th-generation









	  Microsoft Surface devices, i.e. Surface Pro 7, Surface Laptop 3,









	  Surface Book 3, and Surface Laptop Go.



















endif # POWER_SUPPLY
























drivers/power/supply/Makefile



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@@ -101,3 +101,4 @@ obj-$(CONFIG_CHARGER_BD99954)	+= bd99954-charger.o







obj-$(CONFIG_CHARGER_WILCO)	+= wilco-charger.o









obj-$(CONFIG_RN5T618_POWER)	+= rn5t618_power.o









obj-$(CONFIG_BATTERY_ACER_A500)	+= acer_a500_battery.o









obj-$(CONFIG_BATTERY_SURFACE)	+= surface_battery.o
























drivers/power/supply/surface_battery.c
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