firewire-cdev (8c57a5e7b2820f349c95b8c8393fec1e0f4070d2) firewire-cdev (98913408c5465ac477f80da7affe347b413edaa4)
1What: /dev/fw[0-9]+
2Date: May 2007
3KernelVersion: 2.6.22
4Contact: linux1394-devel@lists.sourceforge.net
5Description:
6 The character device files /dev/fw* are the interface between
7 firewire-core and IEEE 1394 device drivers implemented in
8 userspace. The ioctl(2)- and read(2)-based ABI is defined and
9 documented in <linux/firewire-cdev.h>.
10
11 This ABI offers most of the features which firewire-core also
12 exposes to kernelspace IEEE 1394 drivers.
13
14 Each /dev/fw* is associated with one IEEE 1394 node, which can
15 be remote or local nodes. Operations on a /dev/fw* file have
16 different scope:
1What: /dev/fw[0-9]+
2Date: May 2007
3KernelVersion: 2.6.22
4Contact: linux1394-devel@lists.sourceforge.net
5Description:
6 The character device files /dev/fw* are the interface between
7 firewire-core and IEEE 1394 device drivers implemented in
8 userspace. The ioctl(2)- and read(2)-based ABI is defined and
9 documented in <linux/firewire-cdev.h>.
10
11 This ABI offers most of the features which firewire-core also
12 exposes to kernelspace IEEE 1394 drivers.
13
14 Each /dev/fw* is associated with one IEEE 1394 node, which can
15 be remote or local nodes. Operations on a /dev/fw* file have
16 different scope:
17
17 - The 1394 node which is associated with the file:
18 - Asynchronous request transmission
19 - Get the Configuration ROM
20 - Query node ID
21 - Query maximum speed of the path between this node
22 and local node
18 - The 1394 node which is associated with the file:
19 - Asynchronous request transmission
20 - Get the Configuration ROM
21 - Query node ID
22 - Query maximum speed of the path between this node
23 and local node
24
23 - The 1394 bus (i.e. "card") to which the node is attached to:
24 - Isochronous stream transmission and reception
25 - Asynchronous stream transmission and reception
26 - Asynchronous broadcast request transmission
27 - PHY packet transmission and reception
28 - Allocate, reallocate, deallocate isochronous
29 resources (channels, bandwidth) at the bus's IRM
30 - Query node IDs of local node, root node, IRM, bus
31 manager
32 - Query cycle time
33 - Bus reset initiation, bus reset event reception
25 - The 1394 bus (i.e. "card") to which the node is attached to:
26 - Isochronous stream transmission and reception
27 - Asynchronous stream transmission and reception
28 - Asynchronous broadcast request transmission
29 - PHY packet transmission and reception
30 - Allocate, reallocate, deallocate isochronous
31 resources (channels, bandwidth) at the bus's IRM
32 - Query node IDs of local node, root node, IRM, bus
33 manager
34 - Query cycle time
35 - Bus reset initiation, bus reset event reception
36
34 - All 1394 buses:
35 - Allocation of IEEE 1212 address ranges on the local
36 link layers, reception of inbound requests to such
37 an address range, asynchronous response transmission
38 to inbound requests
39 - Addition of descriptors or directories to the local
40 nodes' Configuration ROM
41
42 Due to the different scope of operations and in order to let
43 userland implement different access permission models, some
44 operations are restricted to /dev/fw* files that are associated
45 with a local node:
37 - All 1394 buses:
38 - Allocation of IEEE 1212 address ranges on the local
39 link layers, reception of inbound requests to such
40 an address range, asynchronous response transmission
41 to inbound requests
42 - Addition of descriptors or directories to the local
43 nodes' Configuration ROM
44
45 Due to the different scope of operations and in order to let
46 userland implement different access permission models, some
47 operations are restricted to /dev/fw* files that are associated
48 with a local node:
49
46 - Addition of descriptors or directories to the local
47 nodes' Configuration ROM
48 - PHY packet transmission and reception
49
50 A /dev/fw* file remains associated with one particular node
51 during its entire life time. Bus topology changes, and hence
52 node ID changes, are tracked by firewire-core. ABI users do not
53 need to be aware of topology.

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50 - Addition of descriptors or directories to the local
51 nodes' Configuration ROM
52 - PHY packet transmission and reception
53
54 A /dev/fw* file remains associated with one particular node
55 during its entire life time. Bus topology changes, and hence
56 node ID changes, are tracked by firewire-core. ABI users do not
57 need to be aware of topology.

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