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diff --git a/Documentation/rapidio/sysfs.txt b/Documentation/rapidio/sysfs.txt new file mode 100644 index 000000000..47ce9a533 --- /dev/null +++ b/Documentation/rapidio/sysfs.txt @@ -0,0 +1,158 @@ + RapidIO sysfs Files + +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +1. RapidIO Device Subdirectories +-------------------------------- + +For each RapidIO device, the RapidIO subsystem creates files in an individual +subdirectory with the following name, /sys/bus/rapidio/devices/<device_name>. + +The format of device_name is "nn:d:iiii", where: + +nn - two-digit hexadecimal ID of RapidIO network where the device resides +d - device typr: 'e' - for endpoint or 's' - for switch +iiii - four-digit device destID for endpoints, or switchID for switches + +For example, below is a list of device directories that represents a typical +RapidIO network with one switch, one host, and two agent endpoints, as it is +seen by the enumerating host (destID = 1): + +/sys/bus/rapidio/devices/00:e:0000 +/sys/bus/rapidio/devices/00:e:0002 +/sys/bus/rapidio/devices/00:s:0001 + +NOTE: An enumerating or discovering endpoint does not create a sysfs entry for +itself, this is why an endpoint with destID=1 is not shown in the list. + +2. Attributes Common for All RapidIO Devices +-------------------------------------------- + +Each device subdirectory contains the following informational read-only files: + + did - returns the device identifier + vid - returns the device vendor identifier +device_rev - returns the device revision level + asm_did - returns identifier for the assembly containing the device + asm_rev - returns revision level of the assembly containing the device + asm_vid - returns vendor identifier of the assembly containing the device + destid - returns device destination ID assigned by the enumeration routine + (see 4.1 for switch specific details) + lprev - returns name of previous device (switch) on the path to the device + that that owns this attribute + modalias - returns the device modalias + +In addition to the files listed above, each device has a binary attribute file +that allows read/write access to the device configuration registers using +the RapidIO maintenance transactions: + + config - reads from and writes to the device configuration registers. + +This attribute is similar in behavior to the "config" attribute of PCI devices +and provides an access to the RapidIO device registers using standard file read +and write operations. + +3. RapidIO Endpoint Device Attributes +------------------------------------- + +Currently Linux RapidIO subsystem does not create any endpoint specific sysfs +attributes. It is possible that RapidIO master port drivers and endpoint device +drivers will add their device-specific sysfs attributes but such attributes are +outside the scope of this document. + +4. RapidIO Switch Device Attributes +----------------------------------- + +RapidIO switches have additional attributes in sysfs. RapidIO subsystem supports +common and device-specific sysfs attributes for switches. Because switches are +integrated into the RapidIO subsystem, it offers a method to create +device-specific sysfs attributes by specifying a callback function that may be +set by the switch initialization routine during enumeration or discovery process. + +4.1 Common Switch Attributes + + routes - reports switch routing information in "destID port" format. This + attribute reports only valid routing table entries, one line for + each entry. + destid - device destination ID that defines a route to the switch + hopcount - number of hops on the path to the switch + lnext - returns names of devices linked to the switch except one of a device + linked to the ingress port (reported as "lprev"). This is an array + names with number of lines equal to number of ports in switch. If + a switch port has no attached device, returns "null" instead of + a device name. + +4.2 Device-specific Switch Attributes + +Device-specific switch attributes are listed for each RapidIO switch driver +that exports additional attributes. + +IDT_GEN2: + errlog - reads contents of device error log until it is empty. + + +5. RapidIO Bus Attributes +------------------------- + +RapidIO bus subdirectory /sys/bus/rapidio implements the following bus-specific +attribute: + + scan - allows to trigger enumeration discovery process from user space. This + is a write-only attribute. To initiate an enumeration or discovery + process on specific mport device, a user needs to write mport_ID (not + RapidIO destination ID) into this file. The mport_ID is a sequential + number (0 ... RIO_MAX_MPORTS) assigned to the mport device. + For example, for a machine with a single RapidIO controller, mport_ID + for that controller always will be 0. + To initiate RapidIO enumeration/discovery on all available mports + a user must write '-1' (or RIO_MPORT_ANY) into this attribute file. + + +6. RapidIO Bus Controllers/Ports +-------------------------------- + +On-chip RapidIO controllers and PCIe-to-RapidIO bridges (referenced as +"Master Port" or "mport") are presented in sysfs as the special class of +devices: "rapidio_port". + +The /sys/class/rapidio_port subdirectory contains individual subdirectories +named as "rapidioN" where N = mport ID registered with RapidIO subsystem. + +NOTE: An mport ID is not a RapidIO destination ID assigned to a given local +mport device. + +Each mport device subdirectory in addition to standard entries contains the +following device-specific attributes: + + port_destid - reports RapidIO destination ID assigned to the given RapidIO + mport device. If value 0xFFFFFFFF is returned this means that + no valid destination ID have been assigned to the mport (yet). + Normally, before enumeration/discovery have been executed only + fabric enumerating mports have a valid destination ID assigned + to them using "hdid=..." rapidio module parameter. + sys_size - reports RapidIO common transport system size: + 0 = small (8-bit destination ID, max. 256 devices), + 1 = large (16-bit destination ID, max. 65536 devices). + +After enumeration or discovery was performed for a given mport device, +the corresponding subdirectory will also contain subdirectories for each +child RapidIO device connected to the mport. Naming conventions for RapidIO +devices are described in Section 1 above. + +The example below shows mport device subdirectory with several child RapidIO +devices attached to it. + +[rio@rapidio ~]$ ls /sys/class/rapidio_port/rapidio0/ -l +total 0 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:e:0001 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:e:0004 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:e:0007 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:s:0002 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:s:0003 +drwxr-xr-x 3 root root 0 Feb 11 15:10 00:s:0005 +lrwxrwxrwx 1 root root 0 Feb 11 15:11 device -> ../../../0000:01:00.0 +-r--r--r-- 1 root root 4096 Feb 11 15:11 port_destid +drwxr-xr-x 2 root root 0 Feb 11 15:11 power +lrwxrwxrwx 1 root root 0 Feb 11 15:04 subsystem -> ../../../../../../class/rapidio_port +-r--r--r-- 1 root root 4096 Feb 11 15:11 sys_size +-rw-r--r-- 1 root root 4096 Feb 11 15:04 uevent |