phy: stm32: add support for STM32 USB PHY Controller (USBPHYC)

This patch adds phy transceiver driver for STM32 USB PHY Controller
(USBPHYC) that provides dual port High-Speed phy for OTG (single port)
and EHCI/OHCI host controller (two ports).
One port of the phy is shared between the two USB controllers through
a UTMI+ switch.

[fengguang.wu@intel.com: Make stm32_usbphyc_get_pll_params() to be static]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/st/Kconfig

@@ -31,3 +31,17 @@ config PHY_STIH407_USB
 	help
 	  Enable this support to enable the picoPHY device used by USB2
 	  and USB3 controllers on STMicroelectronics STiH407 SoC families.
+
+config PHY_STM32_USBPHYC
+	tristate "STMicroelectronics STM32 USB HS PHY Controller driver"
+	depends on ARCH_STM32 || COMPILE_TEST
+	select GENERIC_PHY
+	help
+	  Enable this to support the High-Speed USB transceivers that are part
+	  of some STMicroelectronics STM32 SoCs.
+
+	  This driver controls the entire USB PHY block: the USB PHY controller
+	  (USBPHYC) and the two 8-bit wide UTMI+ interfaces. First interface is
+	  used by an HS USB Host controller, and the second one is shared
+	  between an HS USB OTG controller and an HS USB Host controller,
+	  selected by a USB switch.

drivers/phy/st/Makefile

@@ -2,3 +2,4 @@ obj-$(CONFIG_PHY_MIPHY28LP) 		+= phy-miphy28lp.o
 obj-$(CONFIG_PHY_ST_SPEAR1310_MIPHY)	+= phy-spear1310-miphy.o
 obj-$(CONFIG_PHY_ST_SPEAR1340_MIPHY)	+= phy-spear1340-miphy.o
 obj-$(CONFIG_PHY_STIH407_USB)		+= phy-stih407-usb.o
+obj-$(CONFIG_PHY_STM32_USBPHYC) 	+= phy-stm32-usbphyc.o