The PHY framework provides a set of APIs for the PHY drivers to
create/destroy a PHY and APIs for the PHY users to obtain a reference to the
PHY with or without using phandle. To obtain a reference to the PHY without
using phandle, the platform specfic intialization code (say from board file)
should have already called phy_bind with the binding information. The binding
information consists of phy's device name, phy user device name and an index.
The index is used when the same phy user binds to mulitple phys.
+*PHY* is the abbreviation for physical layer. It is used to connect a device
+to the physical medium e.g., the USB controller has a PHY to provide functions
+such as serialization, de-serialization, encoding, decoding and is responsible
+for obtaining the required data transmission rate. Note that some USB
+controller has PHY functionality embedded into it and others use an external
+PHY. Other peripherals that uses a PHY include Wireless LAN, Ethernet,
+The intention of creating this framework is to bring the phy drivers spread
+all over the Linux kernel to drivers/phy to increase code re-use and to
+increase code maintainability.
+This framework will be of use only to devices that uses external PHY (PHY
+functionality is not embedded within the controller).
+2. Creating the PHY
+The PHY driver should create the PHY in order for other peripheral controllers
+to make use of it. The PHY framework provides 2 APIs to create the PHY.
+struct phy *phy_create(struct device *dev, struct phy_descriptor *desc);
+struct phy *devm_phy_create(struct device *dev, struct phy_descriptor *desc);
+The PHY drivers can use one of the above 2 APIs to create the PHY by passing
+6. Destroying the PHY
+7. Current Status
+Currently only USB in OMAP is made to use this framework. However using the
+USB PHY library cannot be completely removed because it is intertwined with
+OTG. Once we move OTG out of PHY completely, using the old PHY library can be
+completely removed. SATA in OMAP will also more likely use this new framework
+and we should have a patch for it soon.