clk: rmobile: Add RCar Gen3 clock driver

Add clock driver for the RCar Gen3 R8A7795 and R8A7796 SoCs .
This driver allows reading out the clock configuration set by
previous boot stages and enabling and disabling clock using
the MSTP registers. Setting clock is not supported thus far.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

drivers/clk/Kconfig

@@ -55,5 +55,6 @@ source "drivers/clk/tegra/Kconfig"
 source "drivers/clk/uniphier/Kconfig"
 source "drivers/clk/exynos/Kconfig"
 source "drivers/clk/at91/Kconfig"
+source "drivers/clk/renesas/Kconfig"
 
 endmenu

drivers/clk/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
 obj-$(CONFIG_SANDBOX) += clk_sandbox.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox_test.o
 obj-$(CONFIG_MACH_PIC32) += clk_pic32.o
+obj-$(CONFIG_CLK_RENESAS) += renesas/
 obj-$(CONFIG_CLK_ZYNQ) += clk_zynq.o
 obj-$(CONFIG_CLK_ZYNQMP) += clk_zynqmp.o
 

drivers/clk/renesas/Kconfig

+config CLK_RENESAS
+	bool "Renesas clock drivers"
+	depends on CLK && ARCH_RMOBILE
+	help
+	  Enable support for clock present on Renesas RCar SoCs.
+
+config CLK_RCAR_GEN3
+	bool "Renesas RCar Gen3 R8A7795/R8A7796 clock driver"
+	def_bool y if RCAR_GEN3
+	depends on CLK_RENESAS
+	help
+	  Enable this to support the clocks on Renesas RCar Gen3
+	  R8A7795 and R8A7796 SoC.

drivers/clk/renesas/Makefile

+obj-$(CONFIG_CLK_RCAR_GEN3) += clk-rcar-gen3.o