memory: Add DMC driver for Exynos5422

Add driver for Exynos5422 Dynamic Memory Controller.  The driver
provides support for dynamic frequency and voltage scaling for DMC and
DRAM.  It supports changing timings of DRAM running with different
frequency.  There is also an algorithm to calculate timings based on
memory description provided in DT.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

MAINTAINERS

@@ -4969,6 +4969,14 @@ F:	include/linux/dma-direct.h
 F:	include/linux/dma-mapping.h
 F:	include/linux/dma-noncoherent.h
 
+DMC FREQUENCY DRIVER FOR SAMSUNG EXYNOS5422
+M:	Lukasz Luba <l.luba@partner.samsung.com>
+L:	linux-pm@vger.kernel.org
+L:	linux-samsung-soc@vger.kernel.org
+S:	Maintained
+F:	drivers/memory/samsung/exynos5422-dmc.c
+F:	Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt
+
 DME1737 HARDWARE MONITOR DRIVER
 M:	Juerg Haefliger <juergh@gmail.com>
 L:	linux-hwmon@vger.kernel.org

drivers/memory/samsung/Kconfig

@@ -7,6 +7,19 @@ config SAMSUNG_MC
 
 if SAMSUNG_MC
 
+config EXYNOS5422_DMC
+	tristate "EXYNOS5422 Dynamic Memory Controller driver"
+	depends on ARCH_EXYNOS || (COMPILE_TEST && HAS_IOMEM)
+	select DDR
+	depends on DEVFREQ_GOV_SIMPLE_ONDEMAND
+	depends on (PM_DEVFREQ && PM_DEVFREQ_EVENT)
+	help
+	  This adds driver for Exynos5422 DMC (Dynamic Memory Controller).
+	  The driver provides support for Dynamic Voltage and Frequency Scaling in
+	  DMC and DRAM. It also supports changing timings of DRAM running with
+	  different frequency. The timings are calculated based on DT memory
+	  information.
+
 config EXYNOS_SROM
 	bool "Exynos SROM controller driver" if COMPILE_TEST
 	depends on (ARM && ARCH_EXYNOS) || (COMPILE_TEST && HAS_IOMEM)

drivers/memory/samsung/Makefile

@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_EXYNOS5422_DMC)	+= exynos5422-dmc.o
 obj-$(CONFIG_EXYNOS_SROM)	+= exynos-srom.o