phy: Add Tegra XUSB pad controller support

Add a new driver for the XUSB pad controller found on NVIDIA Tegra SoCs.
This hardware block used to be exposed as a pin controller, but it turns
out that this isn't a good fit. The new driver and DT binding much more
accurately describe the hardware and are more flexible in supporting new
SoC generations.

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/phy/Kconfig

@@ -421,4 +421,6 @@ config PHY_CYGNUS_PCIE
 	  Enable this to support the Broadcom Cygnus PCIe PHY.
 	  If unsure, say N.
 
+source "drivers/phy/tegra/Kconfig"
+
 endmenu

drivers/phy/Makefile

@@ -52,3 +52,5 @@ obj-$(CONFIG_PHY_TUSB1210)		+= phy-tusb1210.o
 obj-$(CONFIG_PHY_BRCMSTB_SATA)		+= phy-brcmstb-sata.o
 obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
 obj-$(CONFIG_PHY_CYGNUS_PCIE)		+= phy-bcm-cygnus-pcie.o
+
+obj-$(CONFIG_ARCH_TEGRA) += tegra/

drivers/phy/tegra/Kconfig

@@ -0,0 +1,8 @@
+config PHY_TEGRA_XUSB
+	tristate "NVIDIA Tegra XUSB pad controller driver"
+	depends on ARCH_TEGRA
+	help
+	  Choose this option if you have an NVIDIA Tegra SoC.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called phy-tegra-xusb.

drivers/phy/tegra/Makefile

@@ -0,0 +1,5 @@
+obj-$(CONFIG_PHY_TEGRA_XUSB) += phy-tegra-xusb.o
+
+phy-tegra-xusb-y += xusb.o
+phy-tegra-xusb-$(CONFIG_ARCH_TEGRA_124_SOC) += xusb-tegra124.o
+phy-tegra-xusb-$(CONFIG_ARCH_TEGRA_132_SOC) += xusb-tegra124.o