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| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-rpmsg | 95 |
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diff --git a/Documentation/ABI/testing/sysfs-bus-rpmsg b/Documentation/ABI/testing/sysfs-bus-rpmsg new file mode 100644 index 000000000..990fcc420 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-rpmsg @@ -0,0 +1,95 @@ +What: /sys/bus/rpmsg/devices/.../name +Date: June 2011 +KernelVersion: 3.3 +Contact: Ohad Ben-Cohen <ohad@wizery.com> +Description: + Every rpmsg device is a communication channel with a remote + processor. Channels are identified with a (textual) name, + which is maximum 32 bytes long (defined as RPMSG_NAME_SIZE in + rpmsg.h). + + This sysfs entry contains the name of this channel. + +What: /sys/bus/rpmsg/devices/.../src +Date: June 2011 +KernelVersion: 3.3 +Contact: Ohad Ben-Cohen <ohad@wizery.com> +Description: + Every rpmsg device is a communication channel with a remote + processor. Channels have a local ("source") rpmsg address, + and remote ("destination") rpmsg address. When an entity + starts listening on one end of a channel, it assigns it with + a unique rpmsg address (a 32 bits integer). This way when + inbound messages arrive to this address, the rpmsg core + dispatches them to the listening entity (a kernel driver). + + This sysfs entry contains the src (local) rpmsg address + of this channel. If it contains 0xffffffff, then an address + wasn't assigned (can happen if no driver exists for this + channel). + +What: /sys/bus/rpmsg/devices/.../dst +Date: June 2011 +KernelVersion: 3.3 +Contact: Ohad Ben-Cohen <ohad@wizery.com> +Description: + Every rpmsg device is a communication channel with a remote + processor. Channels have a local ("source") rpmsg address, + and remote ("destination") rpmsg address. When an entity + starts listening on one end of a channel, it assigns it with + a unique rpmsg address (a 32 bits integer). This way when + inbound messages arrive to this address, the rpmsg core + dispatches them to the listening entity. + + This sysfs entry contains the dst (remote) rpmsg address + of this channel. If it contains 0xffffffff, then an address + wasn't assigned (can happen if the kernel driver that + is attached to this channel is exposing a service to the + remote processor. This make it a local rpmsg server, + and it is listening for inbound messages that may be sent + from any remote rpmsg client; it is not bound to a single + remote entity). + +What: /sys/bus/rpmsg/devices/.../announce +Date: June 2011 +KernelVersion: 3.3 +Contact: Ohad Ben-Cohen <ohad@wizery.com> +Description: + Every rpmsg device is a communication channel with a remote + processor. Channels are identified by a textual name (see + /sys/bus/rpmsg/devices/.../name above) and have a local + ("source") rpmsg address, and remote ("destination") rpmsg + address. + + A channel is first created when an entity, whether local + or remote, starts listening on it for messages (and is thus + called an rpmsg server). + + When that happens, a "name service" announcement is sent + to the other processor, in order to let it know about the + creation of the channel (this way remote clients know they + can start sending messages). + + This sysfs entry tells us whether the channel is a local + server channel that is announced (values are either + true or false). + +What: /sys/bus/rpmsg/devices/.../driver_override +Date: April 2018 +KernelVersion: 4.18 +Contact: Bjorn Andersson <bjorn.andersson@linaro.org> +Description: + Every rpmsg device is a communication channel with a remote + processor. Channels are identified by a textual name (see + /sys/bus/rpmsg/devices/.../name above) and have a local + ("source") rpmsg address, and remote ("destination") rpmsg + address. + + The listening entity (or client) which communicates with a + remote processor is referred as rpmsg driver. The rpmsg device + and rpmsg driver are matched based on rpmsg device name and + rpmsg driver ID table. + + This sysfs entry allows the rpmsg driver for a rpmsg device + to be specified which will override standard OF, ID table + and name matching. |