diff options
Diffstat (limited to 'Documentation/ABI/stable/firewire-cdev')
| -rw-r--r-- | Documentation/ABI/stable/firewire-cdev | 103 |
1 files changed, 0 insertions, 103 deletions
diff --git a/Documentation/ABI/stable/firewire-cdev b/Documentation/ABI/stable/firewire-cdev deleted file mode 100644 index 16d0308..0000000 --- a/Documentation/ABI/stable/firewire-cdev +++ /dev/null @@ -1,103 +0,0 @@ -What: /dev/fw[0-9]+ -Date: May 2007 -KernelVersion: 2.6.22 -Contact: linux1394-devel@lists.sourceforge.net -Description: - The character device files /dev/fw* are the interface between - firewire-core and IEEE 1394 device drivers implemented in - userspace. The ioctl(2)- and read(2)-based ABI is defined and - documented in <linux/firewire-cdev.h>. - - This ABI offers most of the features which firewire-core also - exposes to kernelspace IEEE 1394 drivers. - - Each /dev/fw* is associated with one IEEE 1394 node, which can - be remote or local nodes. Operations on a /dev/fw* file have - different scope: - - The 1394 node which is associated with the file: - - Asynchronous request transmission - - Get the Configuration ROM - - Query node ID - - Query maximum speed of the path between this node - and local node - - The 1394 bus (i.e. "card") to which the node is attached to: - - Isochronous stream transmission and reception - - Asynchronous stream transmission and reception - - Asynchronous broadcast request transmission - - PHY packet transmission and reception - - Allocate, reallocate, deallocate isochronous - resources (channels, bandwidth) at the bus's IRM - - Query node IDs of local node, root node, IRM, bus - manager - - Query cycle time - - Bus reset initiation, bus reset event reception - - All 1394 buses: - - Allocation of IEEE 1212 address ranges on the local - link layers, reception of inbound requests to such - an address range, asynchronous response transmission - to inbound requests - - Addition of descriptors or directories to the local - nodes' Configuration ROM - - Due to the different scope of operations and in order to let - userland implement different access permission models, some - operations are restricted to /dev/fw* files that are associated - with a local node: - - Addition of descriptors or directories to the local - nodes' Configuration ROM - - PHY packet transmission and reception - - A /dev/fw* file remains associated with one particular node - during its entire life time. Bus topology changes, and hence - node ID changes, are tracked by firewire-core. ABI users do not - need to be aware of topology. - - The following file operations are supported: - - open(2) - Currently the only useful flags are O_RDWR. - - ioctl(2) - Initiate various actions. Some take immediate effect, others - are performed asynchronously while or after the ioctl returns. - See the inline documentation in <linux/firewire-cdev.h> for - descriptions of all ioctls. - - poll(2), select(2), epoll_wait(2) etc. - Watch for events to become available to be read. - - read(2) - Receive various events. There are solicited events like - outbound asynchronous transaction completion or isochronous - buffer completion, and unsolicited events such as bus resets, - request reception, or PHY packet reception. Always use a read - buffer which is large enough to receive the largest event that - could ever arrive. See <linux/firewire-cdev.h> for descriptions - of all event types and for which ioctls affect reception of - events. - - mmap(2) - Allocate a DMA buffer for isochronous reception or transmission - and map it into the process address space. The arguments should - be used as follows: addr = NULL, length = the desired buffer - size, i.e. number of packets times size of largest packet, - prot = at least PROT_READ for reception and at least PROT_WRITE - for transmission, flags = MAP_SHARED, fd = the handle to the - /dev/fw*, offset = 0. - - Isochronous reception works in packet-per-buffer fashion except - for multichannel reception which works in buffer-fill mode. - - munmap(2) - Unmap the isochronous I/O buffer from the process address space. - - close(2) - Besides stopping and freeing I/O contexts that were associated - with the file descriptor, back out any changes to the local - nodes' Configuration ROM. Deallocate isochronous channels and - bandwidth at the IRM that were marked for kernel-assisted - re- and deallocation. - -Users: libraw1394 - libdc1394 - tools like jujuutils, fwhack, ... |