driver-api/rapidio/rio_cm.rst

19 This driver (RIO_CM) provides to user-space applications shared access to
23 messaging mailboxes in case of multi-packet message (up to 4KB) and
24 up to 64 mailboxes if single-packet messages (up to 256 B) are used. In addition
30 capability to large number of user-space processes by introducing socket-like
32 use the limited RapidIO messaging hardware resources efficiently.
39 Following ioctl commands are available to user-space applications:
41 - RIO_CM_MPORT_GET_LIST:
46 - RIO_CM_EP_GET_LIST_SIZE:
49 - RIO_CM_EP_GET_LIST:
53 - RIO_CM_CHAN_CREATE:
54     Creates RapidIO message exchange channel data structure
55     with channel ID assigned automatically or as requested by a caller.
56 - RIO_CM_CHAN_BIND:
57     Binds the specified channel data structure to the specified
59 - RIO_CM_CHAN_LISTEN:
61     channel.
62 - RIO_CM_CHAN_ACCEPT:
64     channel. If wait timeout for this request is specified by a caller it is
65     a blocking call. If timeout set to 0 this is non-blocking call - ioctl
67     exits with -EGAIN error status immediately.
68 - RIO_CM_CHAN_CONNECT:
69     Sends a connection request to a remote peer/channel.
70 - RIO_CM_CHAN_SEND:
71     Sends a data message through the specified channel.
75 - RIO_CM_CHAN_RECEIVE:
76     Receives a data message through a connected channel.
77     If the channel does not have an incoming message ready to return this ioctl
81 - RIO_CM_CHAN_CLOSE:
82     Closes a specified channel and frees associated buffers.
83     If the specified channel is in the CONNECTED state, sends close notification
86 The ioctl command codes and corresponding data structures intended for use by
87 user-space applications are defined in 'include/uapi/linux/rio_cm_cdev.h'.
100 - 'dbg_level'
101       - This parameter allows to control amount of debug information
106         Use CONFIG_RAPIDIO_DEBUG=y to enable debug output at the top level.
108 - 'cmbox'
109       - Number of RapidIO mailbox to use (default value is 1).
115 - 'chstart'
116       - Start channel number for dynamic assignment. Default value - 256.
117         Allows to exclude channel numbers below this parameter from dynamic
118         allocation to avoid conflicts with software components that use
119         reserved predefined channel numbers.
126 5. User-space Applications and API Library
129 Messaging API library and applications that use this device driver are available
135 - Add support for system notification messages (reserved channel 0).