phy: Add Cadence D-PHY support

Cadence has designed a D-PHY that can be used by the, currently in tree,
DSI bridge (DRM), CSI Transceiver and CSI Receiver (v4l2) drivers.

Only the DSI driver has an ad-hoc driver for that phy at the moment, while
the v4l2 drivers are completely missing any phy support. In order to make
that phy support available to all these drivers, without having to
duplicate that code three times, let's create a generic phy framework
driver.
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/cadence/Kconfig

 #
 # Phy drivers for Cadence PHYs
 #
+
 config PHY_CADENCE_DP
 	tristate "Cadence MHDP DisplayPort PHY driver"
 	depends on OF
@@ -9,9 +10,19 @@ config PHY_CADENCE_DP
 	help
 	  Support for Cadence MHDP DisplayPort PHY.
 
+config PHY_CADENCE_DPHY
+	tristate "Cadence D-PHY Support"
+	depends on HAS_IOMEM && OF
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Choose this option if you have a Cadence D-PHY in your
+	  system. If M is selected, the module will be called
+	  cdns-dphy.
+
 config PHY_CADENCE_SIERRA
 	tristate "Cadence Sierra PHY Driver"
 	depends on OF && HAS_IOMEM && RESET_CONTROLLER
 	select GENERIC_PHY
 	help
-	  Enable this to support the Cadence Sierra PHY driver
\ No newline at end of file
+	  Enable this to support the Cadence Sierra PHY driver

drivers/phy/cadence/Makefile

 obj-$(CONFIG_PHY_CADENCE_DP)	+= phy-cadence-dp.o
+obj-$(CONFIG_PHY_CADENCE_DPHY)	+= cdns-dphy.o
 obj-$(CONFIG_PHY_CADENCE_SIERRA)	+= phy-cadence-sierra.o