PM / devfreq: rockchip: add devfreq driver for rk3399 dmc

base on dfi result, we do ddr frequency scaling, register
dmc driver to devfreq framework, and use simple-ondemand
policy.
Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: MyngJoo Ham <myngjoo.ham@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/Kconfig

@@ -100,6 +100,17 @@ config ARM_TEGRA_DEVFREQ
 	  It reads ACTMON counters of memory controllers and adjusts the
 	  operating frequencies and voltages with OPP support.
 
+config ARM_RK3399_DMC_DEVFREQ
+	tristate "ARM RK3399 DMC DEVFREQ Driver"
+	depends on ARCH_ROCKCHIP
+	select DEVFREQ_EVENT_ROCKCHIP_DFI
+	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	select PM_OPP
+	help
+          This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller).
+          It sets the frequency for the memory controller and reads the usage counts
+          from hardware.
+
 source "drivers/devfreq/event/Kconfig"
 
 endif # PM_DEVFREQ

drivers/devfreq/Makefile

@@ -8,6 +8,7 @@ obj-$(CONFIG_DEVFREQ_GOV_PASSIVE)	+= governor_passive.o
 
 # DEVFREQ Drivers
 obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ)	+= exynos-bus.o
+obj-$(CONFIG_ARM_RK3399_DMC_DEVFREQ)	+= rk3399_dmc.o
 obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra-devfreq.o
 
 # DEVFREQ Event Drivers