On Tue, Aug 25, 2015 at 6:50 AM, Florian Fainelli <f.faine...@gmail.com> wrote: > Describe how the DSA subsystem works, its design principles, > limitations, and describe in details how to implement a DSA switch > driver. > > Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
[cut] > +Interactions with other subsystems > +================================== > + > +DSA currently leverages the following subsystems: > + > +- MDIO/PHY library: drivers/net/phy/phy.c, mdio_bus.c > +- Switchdev: net/switchdev/* > +- Device Tree for various of_* functions > +- HWMON: drivers/hwmon/* > + > +MDIO/PHY library > +---------------- > + > +Slave network devices exposed by DSA may or may not be interfacing with PHY > +devices (struct phy_device as defined in include/linux/phy.h), but the DSA > +subsystem deals with all possible combinations: > + > +- internal PHY devices, built into the Ethernet switch hardware > +- external PHY devices, connected via an internal or external MDIO bus > +- internal PHY devices, connected vian an internal MDIO bus > +- special, non-autonegotiated or non MDIO-managed PHY devices: SFPs, MoCA; > aka > + fixed PHYs > + > +The PHY configuration is done by the dsa_slave_phy_setup() function and the > +logic basically looks like this: > + > +- if Device Tree is used, the PHY device is looked up using the standard > + "phy-handle" property, if found, this PHY device is created and registered > + using of_phy_connect() > + > +- if Device Tree is used, and the PHY device is "fixed", that is, conforms to > + the definition of a non-MDIO managed PHY as defined in > + Documentation/devicetree/binding/net/fixed-link.txt, the PHY is the > registered > + and connected to using the special fixed MDIO bus driver transparently > + > +- finally, if the PHY is built into the switch, as is very common with > + standalone switch packages, the PHY is probed using the slave MII bus > created > + by DSA > + > + > +SWITCHDEV > +--------- > + > +DSA directly utilizes SWITCHDEV when interfacing with the bridge layer, and > more > +specifically with its VLAN filtering portion when configuring VLANs on top of > +per-port slave network devices. Since DSA primarily deals with MDIO-connected > +switch, although not exclusively, SWITCHDEV's commit/prepare/ phase > + Missing rest of sentence. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
