xref: /linux/Documentation/ABI/testing/sysfs-bus-rpmsg (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1What:		/sys/bus/rpmsg/devices/.../name
2Date:		June 2011
3KernelVersion:	3.3
4Contact:	Ohad Ben-Cohen <ohad@wizery.com>
5Description:
6		Every rpmsg device is a communication channel with a remote
7		processor. Channels are identified with a (textual) name,
8		which is maximum 32 bytes long (defined as RPMSG_NAME_SIZE in
9		rpmsg.h).
10
11		This sysfs entry contains the name of this channel.
12
13What:		/sys/bus/rpmsg/devices/.../src
14Date:		June 2011
15KernelVersion:	3.3
16Contact:	Ohad Ben-Cohen <ohad@wizery.com>
17Description:
18		Every rpmsg device is a communication channel with a remote
19		processor. Channels have a local ("source") rpmsg address,
20		and remote ("destination") rpmsg address. When an entity
21		starts listening on one end of a channel, it assigns it with
22		a unique rpmsg address (a 32 bits integer). This way when
23		inbound messages arrive to this address, the rpmsg core
24		dispatches them to the listening entity (a kernel driver).
25
26		This sysfs entry contains the src (local) rpmsg address
27		of this channel. If it contains 0xffffffff, then an address
28		wasn't assigned (can happen if no driver exists for this
29		channel).
30
31What:		/sys/bus/rpmsg/devices/.../dst
32Date:		June 2011
33KernelVersion:	3.3
34Contact:	Ohad Ben-Cohen <ohad@wizery.com>
35Description:
36		Every rpmsg device is a communication channel with a remote
37		processor. Channels have a local ("source") rpmsg address,
38		and remote ("destination") rpmsg address. When an entity
39		starts listening on one end of a channel, it assigns it with
40		a unique rpmsg address (a 32 bits integer). This way when
41		inbound messages arrive to this address, the rpmsg core
42		dispatches them to the listening entity.
43
44		This sysfs entry contains the dst (remote) rpmsg address
45		of this channel. If it contains 0xffffffff, then an address
46		wasn't assigned (can happen if the kernel driver that
47		is attached to this channel is exposing a service to the
48		remote processor. This make it a local rpmsg server,
49		and it is listening for inbound messages that may be sent
50		from any remote rpmsg client; it is not bound to a single
51		remote entity).
52
53What:		/sys/bus/rpmsg/devices/.../announce
54Date:		June 2011
55KernelVersion:	3.3
56Contact:	Ohad Ben-Cohen <ohad@wizery.com>
57Description:
58		Every rpmsg device is a communication channel with a remote
59		processor. Channels are identified by a textual name (see
60		/sys/bus/rpmsg/devices/.../name above) and have a local
61		("source") rpmsg address, and remote ("destination") rpmsg
62		address.
63
64		A channel is first created when an entity, whether local
65		or remote, starts listening on it for messages (and is thus
66		called an rpmsg server).
67
68		When that happens, a "name service" announcement is sent
69		to the other processor, in order to let it know about the
70		creation of the channel (this way remote clients know they
71		can start sending messages).
72
73		This sysfs entry tells us whether the channel is a local
74		server channel that is announced (values are either
75		true or false).
76
77What:		/sys/bus/rpmsg/devices/.../driver_override
78Date:		April 2018
79KernelVersion:	4.18
80Contact:	Bjorn Andersson <bjorn.andersson@linaro.org>
81Description:
82		Every rpmsg device is a communication channel with a remote
83		processor. Channels are identified by a textual name (see
84		/sys/bus/rpmsg/devices/.../name above) and have a local
85		("source") rpmsg address, and remote ("destination") rpmsg
86		address.
87
88		The listening entity (or client) which communicates with a
89		remote processor is referred as rpmsg driver. The rpmsg device
90		and rpmsg driver are matched based on rpmsg device name and
91		rpmsg driver ID table.
92
93		This sysfs entry allows the rpmsg driver for a rpmsg device
94		to be specified which will override standard OF, ID table
95		and name matching.
96