thermal: rockchip: add virtual tsadc support for rk3126

rk previous SOCs such as rk3126 have no tsadc module, so a virtual tsadc is
implemented to control the thermal problem.

the virtual tsadc is designed on considering 2 factors, one is heating
modules' heating time and the working frequences, the other one is current
leval monitored by coulometer.

Change-Id: I0c7d8b952004d4f7918a41c925c50d38aaa65673
Signed-off-by: Rocky Hao <rocky.hao@rock-chips.com>

Author: Rocky Hao

drivers/thermal/Kconfig

@@ -212,6 +212,15 @@ config ROCKCHIP_THERMAL
 	  trip point. Cpufreq is used as the cooling device and will throttle
 	  CPUs when the Temperature crosses the passive trip point.
 
+config RK_VIRTUAL_THERMAL
+	tristate "rk_virtual thermal driver"
+	depends on ROCKCHIP_THERMAL
+	help
+	  Rk virtual thermal driver provides virtual temperature support for
+	  SOCs without tsadc module. It supports one critical trip point.
+	  Cpufreq is used as the cooling device and will throttle CPUs when
+	  the Temperature crosses the passive trip point.
+
 config RK3368_THERMAL
 	tristate "rk3368 thermal driver legacy"
 	depends on ROCKCHIP_THERMAL

drivers/thermal/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_QCOM_SPMI_TEMP_ALARM)	+= qcom-spmi-temp-alarm.o
 obj-$(CONFIG_SPEAR_THERMAL)	+= spear_thermal.o
 obj-$(CONFIG_ROCKCHIP_THERMAL)	+= rockchip_thermal.o
 obj-$(CONFIG_RK3368_THERMAL)	+= rk3368_thermal.o
+obj-$(CONFIG_RK_VIRTUAL_THERMAL)	+= rk_virtual_thermal.o
 obj-$(CONFIG_RCAR_THERMAL)	+= rcar_thermal.o
 obj-$(CONFIG_KIRKWOOD_THERMAL)  += kirkwood_thermal.o
 obj-y				+= samsung/