memory: stm32-fmc2-ebi: add STM32 FMC2 EBI controller driver

The driver adds the support for the STMicroelectronics FMC2 EBI controller
found on STM32MP SOCs.
Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1591975362-22009-5-git-send-email-christophe.kerello@st.com

drivers/memory/Kconfig

@@ -174,6 +174,16 @@ config PL353_SMC
 	  This driver is for the ARM PL351/PL353 Static Memory
 	  Controller(SMC) module.
 
+config STM32_FMC2_EBI
+	tristate "Support for FMC2 External Bus Interface on STM32MP SoCs"
+	depends on MACH_STM32MP157 || COMPILE_TEST
+	select MFD_SYSCON
+	help
+	  Select this option to enable the STM32 FMC2 External Bus Interface
+	  controller. This driver configures the transactions with external
+	  devices (like SRAM, ethernet adapters, FPGAs, LCD displays, ...) on
+	  SOCs containing the FMC2 External Bus Interface.
+
 source "drivers/memory/samsung/Kconfig"
 source "drivers/memory/tegra/Kconfig"
 

drivers/memory/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_JZ4780_NEMC)	+= jz4780-nemc.o
 obj-$(CONFIG_MTK_SMI)		+= mtk-smi.o
 obj-$(CONFIG_DA8XX_DDRCTL)	+= da8xx-ddrctl.o
 obj-$(CONFIG_PL353_SMC)		+= pl353-smc.o
+obj-$(CONFIG_STM32_FMC2_EBI)	+= stm32-fmc2-ebi.o
 
 obj-$(CONFIG_SAMSUNG_MC)	+= samsung/
 obj-$(CONFIG_TEGRA_MC)		+= tegra/