clk: keystone: Add sci-clk driver support

In K2G, the clock handling is done through firmware executing on a
separate core. Linux kernel needs to communicate to the firmware
through TI system control interface to access any power management
related resources, including clocks.

The keystone sci-clk driver does this, by communicating to the
firmware through the TI SCI driver. The driver adds support for
registering clocks through DT, and basic required clock operations
like prepare/get_rate, etc.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
[sboyd@codeaurora.org: Make ti_sci_init_clocks() static]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

MAINTAINERS

@@ -12631,6 +12631,7 @@ F:	Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
 F:	include/dt-bindings/genpd/k2g.h
 F:	drivers/soc/ti/ti_sci_pm_domains.c
 F:	Documentation/devicetree/bindings/clock/ti,sci-clk.txt
+F:	drivers/clk/keystone/sci-clk.c
 
 THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
 M:	Hans Verkuil <hverkuil@xs4all.nl>

drivers/clk/Kconfig

@@ -164,13 +164,6 @@ config COMMON_CLK_XGENE
 	---help---
 	  Sypport for the APM X-Gene SoC reference, PLL, and device clocks.
 
-config COMMON_CLK_KEYSTONE
-	tristate "Clock drivers for Keystone based SOCs"
-	depends on (ARCH_KEYSTONE || COMPILE_TEST) && OF
-	---help---
-          Supports clock drivers for Keystone based SOCs. These SOCs have local
-	  a power sleep control module that gate the clock to the IPs and PLLs.
-
 config COMMON_CLK_NXP
 	def_bool COMMON_CLK && (ARCH_LPC18XX || ARCH_LPC32XX)
 	select REGMAP_MMIO if ARCH_LPC32XX
@@ -219,6 +212,7 @@ config COMMON_CLK_VC5
 
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
+source "drivers/clk/keystone/Kconfig"
 source "drivers/clk/mediatek/Kconfig"
 source "drivers/clk/meson/Kconfig"
 source "drivers/clk/mvebu/Kconfig"

drivers/clk/Makefile

@@ -61,7 +61,7 @@ obj-$(CONFIG_H8300)			+= h8300/
 obj-$(CONFIG_ARCH_HISI)			+= hisilicon/
 obj-$(CONFIG_ARCH_MXC)			+= imx/
 obj-$(CONFIG_MACH_INGENIC)		+= ingenic/
-obj-$(CONFIG_COMMON_CLK_KEYSTONE)	+= keystone/
+obj-$(CONFIG_ARCH_KEYSTONE)		+= keystone/
 obj-$(CONFIG_MACH_LOONGSON32)		+= loongson1/
 obj-$(CONFIG_ARCH_MEDIATEK)		+= mediatek/
 obj-$(CONFIG_COMMON_CLK_AMLOGIC)	+= meson/

drivers/clk/keystone/Kconfig

@@ -0,0 +1,15 @@
+config COMMON_CLK_KEYSTONE
+	tristate "Clock drivers for Keystone based SOCs"
+	depends on (ARCH_KEYSTONE || COMPILE_TEST) && OF
+	---help---
+	  Supports clock drivers for Keystone based SOCs. These SOCs have local
+	  a power sleep control module that gate the clock to the IPs and PLLs.
+
+config TI_SCI_CLK
+	tristate "TI System Control Interface clock drivers"
+	depends on (ARCH_KEYSTONE || COMPILE_TEST) && OF
+	default TI_SCI_PROTOCOL
+	---help---
+	  This adds the clock driver support over TI System Control Interface.
+	  If you wish to use clock resources from the PMMC firmware, say Y.
+	  Otherwise, say N.

drivers/clk/keystone/Makefile

@@ -1 +1,2 @@
-obj-y			+= pll.o gate.o
+obj-$(CONFIG_COMMON_CLK_KEYSTONE)	+= pll.o gate.o
+obj-$(CONFIG_TI_SCI_CLK)		+= sci-clk.o