driver-api/rapidio/rapidio.rst

5 The RapidIO standard is a packet-based fabric interconnect standard designed for
8 is publicly available for download from the RTA web-site [1].
17 into the kernel similarly to other buses by defining RapidIO-specific device and
21 architecture-specific interfaces that provide support for common RapidIO
33 ---------------
50 ----------
54 structure. Devices form one global device list and per-network device lists
58 ----------
68 specific switch drivers that are designed to provide hardware-specific
72 -----------
81 ------------------
83 RapidIO device-specific drivers follow Linux Kernel Driver Model and are
87 ------------------------
91 common services may act separately from device-specific drivers or be used by
92 device-specific drivers. Example of such service provider is the RIONET driver
93 which implements Ethernet-over-RapidIO interface. Because only one driver can be
96 the same device without blocking attachment of a device-specific driver.
108 by user-space command.
117 ------------
119 RapidIO subsystem configuration options allow users to build enumeration and
125 Depending on selected enumeration/discovery build configuration, there are
132   'rio-scan.scan' for existing basic enumeration/discovery method.
136   Configuration option CONFIG_RAPIDIO_DISC_TIMEOUT defines time that discovering
140   a user-space command as it is described below (if the given endpoint was
144   a command from user space. This initiation method provides more flexibility
147   started first by issuing a user-space command, after an enumeration is
151   user space. After an enumeration/discovery module is loaded, a network scan
152   process can be started by issuing a user-space command.
165 on RapidIO subsystem build configuration:
170   the command line parameter "rapidio.hdid=-1,7" will result in assignment of
172   one will be assigned destination ID=-1.
178   - from command line: "modprobe rapidio hdid=-1,7", or
179   - from modprobe configuration file using configuration command "options",
180     like in this example: "options rapidio hdid=-1,7". An example of modprobe
181     configuration file is provided in the section below.
185   destination ID = -1;
188   destination ID assignments omitted from the end of list (default = -1).
190 If the host device ID for a specific master port is set to -1, the discovery
194 to access the configuration space of devices.
196 NOTE: If RapidIO switch-specific device drivers are built as loadable modules
199 vendor-specific callbacks on early stages.
202 ------------------------------------------------
204 Automatic enumeration/discovery start method is applicable only to built-in
205 enumeration/discovery RapidIO configuration selection. To enable automatic
207 command line parameter "rio-scan.scan=1".
209 This configuration requires synchronized start of all RapidIO endpoints that
212 controllers have been initialized and are ready to be discovered. Configuration
220 Depending on RapidIO network size and configuration this automatic
224 4.3 User-space Start of Enumeration and Discovery
225 -------------------------------------------------
227 User-space start of enumeration and discovery can be used with built-in and
228 modular build configurations. For user-space controlled start RapidIO subsystem
229 creates the sysfs write-only attribute file '/sys/bus/rapidio/scan'. To initiate
237 write '-1' (or RIO_MPORT_ANY) into the scan attribute file.
240 ----------------------------
254 The enumeration process traverses the network using a recursive depth-first
267 table entry contains a pointer to a switch-specific initialization routine that
271 endpoint if access to its configuration registers is required. If a switch (or
285 (0xFF for 8-bit systems and 0xFFFF for 16-bit systems) is temporarily written
299 devices. This way each Linux-based component of the RapidIO subsystem has
308 -------------------------------------------
311 methods as new configuration options without significant impact to the core
321 -----------------------------------------
325 This process can be automated by specifying pre- or post- dependencies in the
326 RapidIO-specific modprobe configuration file as shown in the example below.
333   options rapidio hdid=-1,2
340   # Load RapidIO switch drivers just before rio-scan enumerator module is loaded
341   softdep rio-scan pre: idt_gen2 idtcps tsi57x
343   --------------------------
362     https://www.kernel.org/doc/ols/2005/ols2005v2-pages-43-56.pdf