xref: /OK3568_Linux_fs/kernel/Documentation/ABI/testing/sysfs-bus-rpmsg (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunWhat:		/sys/bus/rpmsg/devices/.../name
2*4882a593SmuzhiyunDate:		June 2011
3*4882a593SmuzhiyunKernelVersion:	3.3
4*4882a593SmuzhiyunContact:	Ohad Ben-Cohen <ohad@wizery.com>
5*4882a593SmuzhiyunDescription:
6*4882a593Smuzhiyun		Every rpmsg device is a communication channel with a remote
7*4882a593Smuzhiyun		processor. Channels are identified with a (textual) name,
8*4882a593Smuzhiyun		which is maximum 32 bytes long (defined as RPMSG_NAME_SIZE in
9*4882a593Smuzhiyun		rpmsg.h).
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun		This sysfs entry contains the name of this channel.
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunWhat:		/sys/bus/rpmsg/devices/.../src
14*4882a593SmuzhiyunDate:		June 2011
15*4882a593SmuzhiyunKernelVersion:	3.3
16*4882a593SmuzhiyunContact:	Ohad Ben-Cohen <ohad@wizery.com>
17*4882a593SmuzhiyunDescription:
18*4882a593Smuzhiyun		Every rpmsg device is a communication channel with a remote
19*4882a593Smuzhiyun		processor. Channels have a local ("source") rpmsg address,
20*4882a593Smuzhiyun		and remote ("destination") rpmsg address. When an entity
21*4882a593Smuzhiyun		starts listening on one end of a channel, it assigns it with
22*4882a593Smuzhiyun		a unique rpmsg address (a 32 bits integer). This way when
23*4882a593Smuzhiyun		inbound messages arrive to this address, the rpmsg core
24*4882a593Smuzhiyun		dispatches them to the listening entity (a kernel driver).
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun		This sysfs entry contains the src (local) rpmsg address
27*4882a593Smuzhiyun		of this channel. If it contains 0xffffffff, then an address
28*4882a593Smuzhiyun		wasn't assigned (can happen if no driver exists for this
29*4882a593Smuzhiyun		channel).
30*4882a593Smuzhiyun
31*4882a593SmuzhiyunWhat:		/sys/bus/rpmsg/devices/.../dst
32*4882a593SmuzhiyunDate:		June 2011
33*4882a593SmuzhiyunKernelVersion:	3.3
34*4882a593SmuzhiyunContact:	Ohad Ben-Cohen <ohad@wizery.com>
35*4882a593SmuzhiyunDescription:
36*4882a593Smuzhiyun		Every rpmsg device is a communication channel with a remote
37*4882a593Smuzhiyun		processor. Channels have a local ("source") rpmsg address,
38*4882a593Smuzhiyun		and remote ("destination") rpmsg address. When an entity
39*4882a593Smuzhiyun		starts listening on one end of a channel, it assigns it with
40*4882a593Smuzhiyun		a unique rpmsg address (a 32 bits integer). This way when
41*4882a593Smuzhiyun		inbound messages arrive to this address, the rpmsg core
42*4882a593Smuzhiyun		dispatches them to the listening entity.
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun		This sysfs entry contains the dst (remote) rpmsg address
45*4882a593Smuzhiyun		of this channel. If it contains 0xffffffff, then an address
46*4882a593Smuzhiyun		wasn't assigned (can happen if the kernel driver that
47*4882a593Smuzhiyun		is attached to this channel is exposing a service to the
48*4882a593Smuzhiyun		remote processor. This make it a local rpmsg server,
49*4882a593Smuzhiyun		and it is listening for inbound messages that may be sent
50*4882a593Smuzhiyun		from any remote rpmsg client; it is not bound to a single
51*4882a593Smuzhiyun		remote entity).
52*4882a593Smuzhiyun
53*4882a593SmuzhiyunWhat:		/sys/bus/rpmsg/devices/.../announce
54*4882a593SmuzhiyunDate:		June 2011
55*4882a593SmuzhiyunKernelVersion:	3.3
56*4882a593SmuzhiyunContact:	Ohad Ben-Cohen <ohad@wizery.com>
57*4882a593SmuzhiyunDescription:
58*4882a593Smuzhiyun		Every rpmsg device is a communication channel with a remote
59*4882a593Smuzhiyun		processor. Channels are identified by a textual name (see
60*4882a593Smuzhiyun		/sys/bus/rpmsg/devices/.../name above) and have a local
61*4882a593Smuzhiyun		("source") rpmsg address, and remote ("destination") rpmsg
62*4882a593Smuzhiyun		address.
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun		A channel is first created when an entity, whether local
65*4882a593Smuzhiyun		or remote, starts listening on it for messages (and is thus
66*4882a593Smuzhiyun		called an rpmsg server).
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun		When that happens, a "name service" announcement is sent
69*4882a593Smuzhiyun		to the other processor, in order to let it know about the
70*4882a593Smuzhiyun		creation of the channel (this way remote clients know they
71*4882a593Smuzhiyun		can start sending messages).
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun		This sysfs entry tells us whether the channel is a local
74*4882a593Smuzhiyun		server channel that is announced (values are either
75*4882a593Smuzhiyun		true or false).
76*4882a593Smuzhiyun
77*4882a593SmuzhiyunWhat:		/sys/bus/rpmsg/devices/.../driver_override
78*4882a593SmuzhiyunDate:		April 2018
79*4882a593SmuzhiyunKernelVersion:	4.18
80*4882a593SmuzhiyunContact:	Bjorn Andersson <bjorn.andersson@linaro.org>
81*4882a593SmuzhiyunDescription:
82*4882a593Smuzhiyun		Every rpmsg device is a communication channel with a remote
83*4882a593Smuzhiyun		processor. Channels are identified by a textual name (see
84*4882a593Smuzhiyun		/sys/bus/rpmsg/devices/.../name above) and have a local
85*4882a593Smuzhiyun		("source") rpmsg address, and remote ("destination") rpmsg
86*4882a593Smuzhiyun		address.
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun		The listening entity (or client) which communicates with a
89*4882a593Smuzhiyun		remote processor is referred as rpmsg driver. The rpmsg device
90*4882a593Smuzhiyun		and rpmsg driver are matched based on rpmsg device name and
91*4882a593Smuzhiyun		rpmsg driver ID table.
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun		This sysfs entry allows the rpmsg driver for a rpmsg device
94*4882a593Smuzhiyun		to be specified which will override standard OF, ID table
95*4882a593Smuzhiyun		and name matching.
96