On Wed, 3 Jun 2020 at 20:05, Maxim Uvarov <maxim.uvarov@xxxxxxxxxx> wrote: > > Hello Sumit, > > if this doc is for driver developers it might be useful to add some > code examples how to register drivers on tee bus. Sure, will add an example TEE client driver snippet for reference. -Sumit > > Best regards, > Maxim. > > On Wed, 3 Jun 2020 at 14:31, Sumit Garg <sumit.garg@xxxxxxxxxx> wrote: > > > > Update documentation with TEE bus infrastructure which provides an > > interface for kernel client drivers to communicate with corresponding > > Trusted Application. > > > > Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx> > > --- > > Documentation/tee.txt | 30 ++++++++++++++++++++++++++++++ > > 1 file changed, 30 insertions(+) > > > > diff --git a/Documentation/tee.txt b/Documentation/tee.txt > > index c8fad81..428d3b5 100644 > > --- a/Documentation/tee.txt > > +++ b/Documentation/tee.txt > > @@ -53,6 +53,28 @@ clients, forward them to the TEE and send back the results. In the case of > > supplicants the communication goes in the other direction, the TEE sends > > requests to the supplicant which then sends back the result. > > > > +The TEE kernel interface > > +======================== > > + > > +Kernel provides a TEE bus infrastructure where a Trusted Application is > > +represented as a device identified via Universally Unique Identifier (UUID) and > > +client drivers register a table of supported device UUIDs. > > + > > +TEE bus infrastructure registers following APIs: > > +- match(): iterates over the client driver UUID table to find a corresponding > > + match for device UUID. If a match is found, then this particular device is > > + probed via corresponding probe API registered by the client driver. This > > + process happens whenever a device or a client driver is registered with TEE > > + bus. > > +- uevent(): notifies user-space (udev) whenever a new device is registered on > > + TEE bus for auto-loading of modularized client drivers. > > + > > +TEE bus device enumeration is specific to underlying TEE implementation, so it > > +is left open for TEE drivers to provide corresponding implementation. > > + > > +Then TEE client driver can talk to a matched Trusted Application using APIs > > +listed in include/linux/tee_drv.h. > > + > > OP-TEE driver > > ============= > > > > @@ -112,6 +134,14 @@ kernel are handled by the kernel driver. Other RPC messages will be forwarded to > > tee-supplicant without further involvement of the driver, except switching > > shared memory buffer representation. > > > > +OP-TEE device enumeration > > +------------------------- > > + > > +OP-TEE provides a pseudo Trusted Application: drivers/tee/optee/device.c in > > +order to support device enumeration. In other words, OP-TEE driver invokes this > > +application to retrieve a list of Trusted Applications which can be registered > > +as devices on the TEE bus. > > + > > AMD-TEE driver > > ============== > > > > -- > > 2.7.4 > >
