diff options
Diffstat (limited to 'Documentation/ABI/stable/firewire-cdev')
| -rw-r--r-- | Documentation/ABI/stable/firewire-cdev | 69 |
1 files changed, 38 insertions, 31 deletions
diff --git a/Documentation/ABI/stable/firewire-cdev b/Documentation/ABI/stable/firewire-cdev index f72ed653878a..261f85b13154 100644 --- a/Documentation/ABI/stable/firewire-cdev +++ b/Documentation/ABI/stable/firewire-cdev @@ -14,13 +14,17 @@ Description: 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 @@ -31,7 +35,9 @@ Description: 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 @@ -43,6 +49,7 @@ Description: 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 @@ -55,50 +62,50 @@ Description: The following file operations are supported: open(2) - Currently the only useful flags are O_RDWR. + 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. + 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. + 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. + 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. + 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. + 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 - libhinawa + 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; + libhinawa; tools like linux-firewire-utils, fwhack, ... |