clk: npcm8xx: add clock controller

Add auxiliary driver to support Nuvoton Arbel BMC NPCM8XX contains an
integrated clock controller which generates and supplies clocks to all
modules within the BMC.

The NPCM8xx clock controller is created using the auxiliary device
framework and set up in the npcm reset driver since the NPCM8xx clock is
using the same register region.

Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
Tested-by: Benjamin Fair <benjaminfair@google.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240912191038.981105-4-tmaimon77@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/Kconfig

@@ -342,6 +342,14 @@ config COMMON_CLK_LOCHNAGAR
 	  This driver supports the clocking features of the Cirrus Logic
 	  Lochnagar audio development board.
 
+config COMMON_CLK_NPCM8XX
+	tristate "Clock driver for the NPCM8XX SoC Family"
+	depends on ARCH_NPCM || COMPILE_TEST
+	help
+	  This driver supports the clocks on the Nuvoton BMC NPCM8XX SoC Family,
+	  all the clocks are initialized by the bootloader, so this driver
+	  allows only reading of current settings directly from the hardware.
+
 config COMMON_CLK_LOONGSON2
 	bool "Clock driver for Loongson-2 SoC"
 	depends on LOONGARCH || COMPILE_TEST

drivers/clk/Makefile

@@ -62,6 +62,7 @@ obj-$(CONFIG_ARCH_MILBEAUT_M10V)	+= clk-milbeaut.o
 obj-$(CONFIG_ARCH_MOXART)		+= clk-moxart.o
 obj-$(CONFIG_ARCH_NOMADIK)		+= clk-nomadik.o
 obj-$(CONFIG_ARCH_NPCM7XX)	    	+= clk-npcm7xx.o
+obj-$(CONFIG_COMMON_CLK_NPCM8XX)	+= clk-npcm8xx.o
 obj-$(CONFIG_ARCH_NSPIRE)		+= clk-nspire.o
 obj-$(CONFIG_COMMON_CLK_PALMAS)		+= clk-palmas.o
 obj-$(CONFIG_CLK_LS1028A_PLLDIG)	+= clk-plldig.o