platform/x86: Add new msi-ec driver

Add a new driver to allow various MSI laptops' functionalities to be
controlled from userspace. This includes such features as power
profiles (aka shift modes), fan speed, charge thresholds, LEDs, etc.

This driver contains EC memory configurations for different firmware
versions and exports battery charge thresholds to userspace (note,
that start and end thresholds control the same EC parameter
and are always 10% apart).

Link: https://github.com/BeardOverflow/msi-ec/
Link: https://github.com/BeardOverflow/msi-ec/pull/13
Cc: Aakash Singh <mail@singhaakash.dev>
Cc: Jose Angel Pastrana <japp0005@red.ujaen.es>
Signed-off-by: Nikita Kravets <teackot@gmail.com>
Link: https://lore.kernel.org/r/20230320225509.3559-1-teackot@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

MAINTAINERS

@@ -14138,6 +14138,13 @@ S:	Odd Fixes
 F:	Documentation/devicetree/bindings/net/ieee802154/mrf24j40.txt
 F:	drivers/net/ieee802154/mrf24j40.c
 
+MSI EC DRIVER
+M:	Nikita Kravets <teackot@gmail.com>
+L:	platform-driver-x86@vger.kernel.org
+S:	Maintained
+W:	https://github.com/BeardOverflow/msi-ec
+F:	drivers/platform/x86/msi-ec.*
+
 MSI LAPTOP SUPPORT
 M:	"Lee, Chun-Yi" <jlee@suse.com>
 L:	platform-driver-x86@vger.kernel.org

drivers/platform/x86/Kconfig

@@ -635,6 +635,14 @@ config THINKPAD_LMI
 
 source "drivers/platform/x86/intel/Kconfig"
 
+config MSI_EC
+	tristate "MSI EC Extras"
+	depends on ACPI
+	depends on ACPI_BATTERY
+	help
+	  This driver allows various MSI laptops' functionalities to be
+	  controlled from userspace, including battery charge threshold.
+
 config MSI_LAPTOP
 	tristate "MSI Laptop Extras"
 	depends on ACPI

drivers/platform/x86/Makefile

@@ -70,6 +70,7 @@ obj-$(CONFIG_THINKPAD_LMI)	+= think-lmi.o
 obj-y				+= intel/
 
 # MSI
+obj-$(CONFIG_MSI_EC)		+= msi-ec.o
 obj-$(CONFIG_MSI_LAPTOP)	+= msi-laptop.o
 obj-$(CONFIG_MSI_WMI)		+= msi-wmi.o