power: supply: macsmc_power: Driver for Apple SMC power/battery stats

This driver implements support for battery stats on top of the macsmc
framework, to support Apple M1 Mac machines.

power: supply: macsmc_power: Add cycle count and health props

power: supply: macsmc_power: Add present prop

power: supply: macsmc_power: Add more props, rework others

power: supply: macsmc_power: Use BUIC instead of BRSC for charge

power: supply: macsmc_power: Turn off OBC flags if macOS left them on

power: supply: macsmc_power: Add AC power supply

power: supply: macsmc_power: Add critical level shutdown & misc events

power: supply: macsmc_power: Add CHWA charge thresholds

This is a hardcoded charge threshold feature present in firmware 13.0 or
newer. Userspace settings are rounded to one of the two possible
behaviors.

power: supply: macsmc_power: Report available charge_behaviours

The generic handling if charge_behaviours in the power_supply core
requires power_supply_desc.charge_behaviours to be set.

power: supply: macsmc_power: Add more properties

Report more voltages from the battery, and also fudge energy numbers
from charge numbers. This way userspace doesn't try to convert on its
own (and gets it very wrong).

power: supply: macsmc_power: Add CHLS charge thresholds

Since macOS Sequoia firmware, CHLS replaced CHWA and now allows an
arbitrary end charge threshold to be configured.

Prefer CHWA over CHLS since the SMC firmware from iBoot-10151.1.1
(macOS 14.0) is not compatible with our CHGLS usage. It was working
with the SMC firmware from iBoot-10151.121.1 (macOS 14.5).

power: supply: macsmc_power: Remove CSIL

Gone in Sequoia firmware.

power: supply: macsmc_power: Report not charging for CHLS thresholds

If a CHLS charge threshold is configured and the current SoC is above
the start threshold report a busy BMS as not charging.

power: supply: macsmc_power: Report only supported properties

The SMC firmware in macOS 15.4 dropped "AC-i" and "AC-n" (and all keys
with lower case last letter) without obvious replacement. Stop reporting
VOLTAGE_NOW / INPUT_CURRENT_LIMIT if "AC-n" is not present.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Co-developed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Janne Grunau <j@jannau.net>
Co-developed-by: Janne Grunau <j@jannau.net>
Co-authored-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Hector Martin <marcan@marcan.st>

Author: 2 people

drivers/mfd/macsmc.c

@@ -46,6 +46,7 @@
 
 static const struct mfd_cell apple_smc_devs[] = {
 	MFD_CELL_NAME("macsmc-input"),
+	MFD_CELL_NAME("macsmc-power"),
 	MFD_CELL_OF("macsmc-gpio", NULL, NULL, 0, 0, "apple,smc-gpio"),
 	MFD_CELL_OF("macsmc-hwmon", NULL, NULL, 0, 0, "apple,smc-hwmon"),
 	MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"),

drivers/power/supply/Kconfig

@@ -1132,4 +1132,11 @@ config FUEL_GAUGE_MM8013
 	  the state of charge, temperature, cycle count, actual and design
 	  capacity, etc.
 
+config CHARGER_MACSMC
+	tristate "Apple SMC Charger / Battery support"
+	depends on MFD_MACSMC
+	help
+	  Say Y here to enable support for the charger and battery controls on
+	  Apple SMC controllers, as used on Apple Silicon Macs.
+
 endif # POWER_SUPPLY

drivers/power/supply/Makefile

@@ -81,6 +81,7 @@ obj-$(CONFIG_CHARGER_GPIO)	+= gpio-charger.o
 obj-$(CONFIG_CHARGER_MANAGER)	+= charger-manager.o
 obj-$(CONFIG_CHARGER_LT3651)	+= lt3651-charger.o
 obj-$(CONFIG_CHARGER_LTC4162L)	+= ltc4162-l-charger.o
+obj-$(CONFIG_CHARGER_MACSMC)	+= macsmc-power.o
 obj-$(CONFIG_CHARGER_MAX14577)	+= max14577_charger.o
 obj-$(CONFIG_CHARGER_DETECTOR_MAX14656)	+= max14656_charger_detector.o
 obj-$(CONFIG_CHARGER_MAX77650)	+= max77650-charger.o