Content-type: text/html Man page of libdevinfo

libdevinfo

Section: Interface Libraries (3LIB)
Updated: 28 Sep 2004
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NAME

libdevinfo - device information library  

SYNOPSIS

cc [ flag... ] file... -ldevinfo [ library... ]
#include <libdevinfo.h>
 

DESCRIPTION

Functions in this library access device configuration information.

Device configuration data is organized as a tree of device nodes, defined as di_node_t in the libdevinfo interfaces. Each di_node_t represents a physical or logical (pseudo) device. Three types of data are associated with device nodes:

• data defined for all device nodes (attributes)

• properties specific to each device

• minor node data

All device nodes have a set of common attributes, such as a node name, an instance number, and a driver binding name. Common device node attributes are accessed by calling interfaces listed on the di_binding_name(3DEVINFO) manual page. Each device node also has a physical path, which is accessed by calling di_devfs_path(3DEVINFO).

Properties provide device specific information for device configuration and usage. Properties can be defined by software (di_prop_t) or by firmware (di_prom_prop_t). One way to access each di_prop_t is to make successive calls to di_prop_next(3DEVINFO) until DI_PROP_NIL is returned. For each di_prop_t, use interfaces on the di_prop_bytes(3DEVINFO) manual page to obtain property names and values. Another way to access these properties is to call di_prop_lookup_bytes(3DEVINFO) to find the value of a property with a given name. Accessing a di_prom_prop_t is similar to accessing a di_prop_t, except that the interface names start with di_prom_prop and additional calls to di_prom_init(3DEVINFO) and di_prom_fini(3DEVINFO) are required.

Minor nodes contain information exported by the device for creating special files for the device. Each device node has 0 or more minor nodes associated with it. A list minor nodes (di_minor_t) can be obtained by making successive calls to di_minor_next(3DEVINFO) until DI_MINOR_NIL is returned. For each minor node, di_minor_devt(3DEVINFO) and related interfaces are called to get minor node data.

Using libdevinfo involves three steps:

• Creating a snapshot of the device tree

• Traversing the device tree to get information of interest

• Destroying the snapshot of the device tree

A snapshot of the device tree is created by calling di_init(3DEVINFO) and destroyed by calling di_fini(3DEVINFO). An application can specify the data to be included in the snapshot (full or partial tree, include or exclude properties and minor nodes) and get a handle to the root of the device tree. See di_init(3DEVINFO) for details. The application then traverses the device tree in the snapshot to obtain device configuration data.

The device tree is normally traversed through parent-child-sibling linkage. Each device node contains references to its parent, its next sibling, and the first of its children. Given the di_node_t returned from di_init(), one can find all children by first calling di_child_node(3DEVINFO), followed by successive calls to di_sibling_node(3DEVINFO) until DI_NODE_NIL is returned. By following this procedure recursively, an application can visit all device nodes contained in the snapshot. Two interfaces,The di_walk_node(3DEVINFO) and di_walk_minor(3DEVINFO) functions are provided to facilitate device tree traversal. The di_walk_node() function visits all device nodes and executes a user-supplied callback function for each node visited. The di_walk_minor() function does the same for each minor node in the device tree.

An alternative way to traverse the device tree is through the per-driver device node linkage. Device nodes contain a reference to the next device node bound to the same driver. Given the di_node_t returned from di_init(), an application can find all device nodes bound to a driver by first calling di_drv_first_node(3DEVINFO), followed by successive calls to di_drv_next_node(3DEVINFO) until DI_NODE_NIL is returned. Traversing the per-driver device node list works only when the snapshot includes all device nodes.

See di_init(3DEVINFO) for examples of libdevinfo usage. See Writing Device Drivers for information about Solaris device configuration.  

INTERFACES

The shared object libdevinfo.so.1 provides the public interfaces defined below. See intro(3) for additional information on shared object interfaces.

di_binding_namedi_bus_addr
di_child_nodedi_compatible_names
di_devfs_minor_pathdi_devfs_path
di_devfs_path_freedi_devid
di_driver_majordi_driver_name
di_driver_opsdi_drv_first_node
di_drv_next_nodedi_fini
di_initdi_instance
di_link_next_by_lnodedi_link_next_by_node
di_link_private_getdi_link_private_set
di_link_spectypedi_link_to_lnode
di_lnode_devinfodi_lnode_devt
di_lnode_namedi_lnode_next
di_lnode_private_getdi_lnode_private_set
di_minor_devtdi_minor_name
di_minor_nextdi_minor_nodetype
di_minor_private_getdi_minor_private_set
di_minor_spectypedi_minor_type
di_node_namedi_nodeid
di_parent_nodedi_node_private_get
di_node_private_setdi_prom_fini
di_prom_initdi_prom_prop_data
di_prom_prop_lookup_bytesdi_prom_prop_lookup_ints
di_prom_prop_lookup_stringsdi_prom_prop_name
di_prom_prop_nextdi_prop_bytes
di_prop_devtdi_prop_int64
di_prop_intsdi_prop_lookup_bytes
di_prop_lookup_int64di_prop_lookup_ints
di_prop_lookup_stringsdi_prop_name
di_prop_nextdi_prop_strings
di_prop_typedi_sibling_node
di_statedi_walk_link
di_walk_lnodedi_walk_minor
di_walk_node

 

EXAMPLES

Example 1: Information accessible through libdevinfo interfaces

The following example illustrates the kind of information accessible through libdevinfo interfaces for a device node representing a hard disk (sd2):

Attributes
    node name:  sd
    instance:   2
    physical path:  [email protected],[email protected],[email protected],[email protected],0

Properties
    target=2
    lun=0

Minor nodes
    (disk partition /dev/dsk/c0t2d0s0)
        name:       a
        dev_t:      0x0080010 (32/16)
        spectype:   IF_BLK (block special)
    (disk partition /dev/rdsk/c0t2d0s2)
        name:       c,raw
        dev_t:      0x0080012 (32/18)
        spectype:   IF_CHR (character special)
 

FILES

/lib/libdevinfo.so.1 shared object

/usr/lib/64/libdevinfo.so.1 64-bit shared object

 

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPEATTRIBUTE VALUE
Availability SUNWcsl, SUNWstatl (32-bit)
SUNWcslx (64-bit)
Interface StabilityEvolving
MT-LevelSafe

 

SEE ALSO

pvs(1), devlinks(1M), prtconf(1M), intro(3), di_binding_name(3DEVINFO), di_child_node(3DEVINFO), di_devfs_path(3DEVINFO), di_drv_first_node(3DEVINFO), di_drv_next_node(3DEVINFO), di_fini(3DEVINFO), di_prom_init(3DEVINFO), di_minor_devt(3DEVINFO), di_minor_next(3DEVINFO), di_prom_fini(3DEVINFO), di_prom_init(3DEVINFO), di_prop_bytes(3DEVINFO), di_prop_lookup_bytes(3DEVINFO), di_prop_next(3DEVINFO), di_sibling_node(3DEVINFO), di_walk_minor(3DEVINFO), di_walk_node(3DEVINFO), attributes(5)

Writing Device Drivers


 

Index

NAME
SYNOPSIS
DESCRIPTION
INTERFACES
EXAMPLES
FILES
ATTRIBUTES
SEE ALSO

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Time: 02:38:41 GMT, October 02, 2010