dpll: core: Add DPLL framework base functions

DPLL framework is used to represent and configure DPLL devices
in systems. Each device that has DPLL and can configure inputs
and outputs can use this framework.

Implement core framework functions for further interactions
with device drivers implementing dpll subsystem, as well as for
interactions of DPLL netlink framework part with the subsystem
itself.

Co-developed-by: Milena Olech <[email protected]>
Signed-off-by: Milena Olech <[email protected]>
Co-developed-by: Michal Michalik <[email protected]>
Signed-off-by: Michal Michalik <[email protected]>
Signed-off-by: Vadim Fedorenko <[email protected]>
Co-developed-by: Arkadiusz Kubalewski <[email protected]>
Signed-off-by: Arkadiusz Kubalewski <[email protected]>
Signed-off-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Vadim Fedorenko

MAINTAINERS

@@ -6333,6 +6333,17 @@ F:	Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-drive
 F:	drivers/net/ethernet/freescale/dpaa2/dpaa2-switch*
 F:	drivers/net/ethernet/freescale/dpaa2/dpsw*
 
+DPLL SUBSYSTEM
+M:	Vadim Fedorenko <[email protected]>
+M:	Arkadiusz Kubalewski <[email protected]>
+M:	Jiri Pirko <[email protected]>
+L:	[email protected]
+S:	Supported
+F:	Documentation/driver-api/dpll.rst
+F:	drivers/dpll/*
+F:	include/net/dpll.h
+F:	include/uapi/linux/dpll.h
+
 DRBD DRIVER
 M:	Philipp Reisner <[email protected]>
 M:	Lars Ellenberg <[email protected]>

drivers/Kconfig

@@ -243,4 +243,6 @@ source "drivers/hte/Kconfig"
 
 source "drivers/cdx/Kconfig"
 
+source "drivers/dpll/Kconfig"
+
 endmenu

drivers/Makefile

@@ -197,5 +197,6 @@ obj-$(CONFIG_PECI)		+= peci/
 obj-$(CONFIG_HTE)		+= hte/
 obj-$(CONFIG_DRM_ACCEL)		+= accel/
 obj-$(CONFIG_CDX_BUS)		+= cdx/
+obj-$(CONFIG_DPLL)		+= dpll/
 
 obj-$(CONFIG_S390)		+= s390/

drivers/dpll/Kconfig

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Generic DPLL drivers configuration
+#
+
+config DPLL
+  bool

drivers/dpll/Makefile

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for DPLL drivers.
+#
+
+obj-$(CONFIG_DPLL)      += dpll.o
+dpll-y                  += dpll_core.o
+dpll-y                  += dpll_netlink.o
+dpll-y                  += dpll_nl.o