thermal: Intel SoC DTS thermal

In the Intel SoCs like Bay Trail, there are 2 additional digital temperature
sensors(DTS), in addition to the standard DTSs in the core. Also they support
4 programmable thresholds, out of which two can be used by OSPM. These
thresholds can be used by OSPM thermal control. Out of these two thresholds,
one is used by driver and one user mode can change via thermal sysfs to get
notifications on threshold violations.

The driver defines one critical trip points, which is set to TJ MAX - offset.
The offset can be changed via module parameter (default 5C). Also it uses
one of the thresholds to get notification for this temperature violation.
This is very important for orderly shutdown as the many of these devices don't
have ACPI thermal zone, and expects that there is some other thermal control
mechanism present in OSPM. When a Linux distro is used without additional
specialized thermal control program, BIOS can do force shutdown when thermals
are not under control. When temperature reaches critical, the Linux thermal
core will initiate an orderly shutdown.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/Kconfig

@@ -222,6 +222,18 @@ config ACPI_INT3403_THERMAL
 	  the Intel Thermal Daemon can use this information to allow the user
 	  to select his laptop to run without turning on the fans.
 
+config INTEL_SOC_DTS_THERMAL
+	tristate "Intel SoCs DTS thermal driver"
+	depends on X86 && IOSF_MBI
+	help
+	  Enable this to register Intel SoCs (e.g. Bay Trail) platform digital
+	  temperature sensor (DTS). These SoCs have two additional DTSs in
+	  addition to DTSs on CPU cores. Each DTS will be registered as a
+	  thermal zone. There are two trip points. One of the trip point can
+	  be set by user mode programs to get notifications via Linux thermal
+	  notification methods.The other trip is a critical trip point, which
+	  was set by the driver based on the TJ MAX temperature.
+
 menu "Texas Instruments thermal drivers"
 source "drivers/thermal/ti-soc-thermal/Kconfig"
 endmenu

drivers/thermal/Makefile

@@ -29,5 +29,6 @@ obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
 obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
 obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
 obj-$(CONFIG_X86_PKG_TEMP_THERMAL)	+= x86_pkg_temp_thermal.o
+obj-$(CONFIG_INTEL_SOC_DTS_THERMAL)	+= intel_soc_dts_thermal.o
 obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
 obj-$(CONFIG_ACPI_INT3403_THERMAL)	+= int3403_thermal.o