thermal/drivers/mediatek: Add the Low Voltage Thermal Sensor driver

The Low Voltage Thermal Sensor (LVTS) is a multiple sensors, multi
controllers contained in a thermal domain.

A thermal domains can be the MCU or the AP.

Each thermal domains contain up to seven controllers, each thermal
controller handle up to four thermal sensors.

The LVTS has two Finite State Machines (FSM), one to handle the
functionin temperatures range like hot or cold temperature and another
one to handle monitoring trip point. The FSM notifies via interrupts
when a trip point is crossed.

The interrupt is managed at the thermal controller level, so when an
interrupt occurs, the driver has to find out which sensor triggered
such an interrupt.

The sampling of the thermal can be filtered or immediate. For the
former, the LVTS measures several points and applies a low pass
filter.

Signed-off-by: Balsam CHIHI <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>

On MT8195 Tomato Chromebook:

Tested-by: AngeloGioacchino Del Regno <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Lezcano <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

Author: bchihiBL

drivers/thermal/mediatek/Kconfig

@@ -18,4 +18,20 @@ config MTK_SOC_THERMAL
 	  This driver configures thermal controllers to collect
 	  temperature via AUXADC interface.
 
+config MTK_LVTS_THERMAL
+        tristate "LVTS Thermal Driver for MediaTek SoCs"
+        depends on HAS_IOMEM
+        help
+          Enable this option if you want to get SoC temperature
+          information for supported MediaTek platforms.
+          This driver configures LVTS (Low Voltage Thermal Sensor)
+          thermal controllers to collect temperatures via ASIF
+          (Analog Serial Interface).
+
+config MTK_LVTS_THERMAL_DEBUGFS
+       bool "LVTS thermal debugfs"
+       depends on MTK_LVTS_THERMAL && DEBUG_FS
+       help
+         Enable this option to debug the internals of the device driver.
+
 endif

drivers/thermal/mediatek/Makefile

@@ -1 +1,2 @@
 obj-$(CONFIG_MTK_SOC_THERMAL)	+= auxadc_thermal.o
+obj-$(CONFIG_MTK_LVTS_THERMAL)	+= lvts_thermal.o