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diff --git a/Documentation/rapidio/sysfs.txt b/Documentation/rapidio/sysfs.txt new file mode 100644 index 000000000000..97f71ce575d6 --- /dev/null +++ b/Documentation/rapidio/sysfs.txt @@ -0,0 +1,90 @@ + RapidIO sysfs Files + +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +1. 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 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 + +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. 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. 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. |