AUTOCONF(9) | Kernel Developer's Manual | AUTOCONF(9) |
autoconf
, config_search_loc
,
config_search_ia
,
config_found_sm_loc
,
config_found_ia
, config_found
,
config_match
,
config_attach_loc
,
config_attach
,
config_attach_pseudo
,
config_detach
,
config_detach_children
,
config_deactivate
,
config_defer
,
config_interrupts
,
config_mountroot
,
config_pending_incr
,
config_pending_decr
,
config_finalize_register
—
#include <sys/param.h>
#include <sys/device.h>
#include <sys/errno.h>
cfdata_t
config_search_loc
(cfsubmatch_t
func, device_t
parent, const char
*ia, const int
*locs, void
*aux);
cfdata_t
config_search_ia
(cfsubmatch_t
func, device_t
parent, const char
*ia, void
*aux);
device_t
config_found_sm_loc
(device_t
parent, const char
*ia, const int
*locs, void *aux,
cfprint_t print,
cfsubmatch_t
submatch);
device_t
config_found_ia
(device_t
parent, const char
*ia, void *aux,
cfprint_t print);
device_t
config_found
(device_t
parent, void *aux,
cfprint_t print);
int
config_match
(device_t
parent, cfdata_t
cf, void *aux);
device_t
config_attach_loc
(device_t
parent, cfdata_t
cf, const int
*locs, void *aux,
cfprint_t print);
device_t
config_attach
(device_t
parent, cfdata_t
cf, void *aux,
cfprint_t print);
device_t
config_attach_pseudo
(cfdata_t
cf);
int
config_detach
(device_t
dev, int
flags);
int
config_detach_children
(device_t
dev, int
flags);
int
config_deactivate
(device_t
dev);
int
config_defer
(device_t
dev, void
(*func)(device_t));
void
config_interrupts
(device_t
dev, void
(*func)(device_t));
void
config_mountroot
(device_t
dev, void
(*func)(device_t));
void
config_pending_incr
();
void
config_pending_decr
();
int
config_finalize_register
(device_t
dev, int
(*func)(device_t));
The autoconfiguration framework supports direct configuration where the bus driver can determine the devices present. The autoconfiguration framework also supports indirect configuration where the drivers must probe the bus looking for the presence of a device. Direct configuration is preferred since it can find hardware regardless of the presence of proper drivers.
The autoconfiguration process occurs at system bootstrap and is driven by a table generated from a “machine description” file by config(1). For a description of the config(1) “device definition” language, see config(9).
Each device must have a name consisting of an alphanumeric string that ends with a unit number. The unit number identifies an instance of the driver. Device data structures are allocated dynamically during autoconfiguration, giving a unique address for each instance.
config_search_loc
(func,
parent, ia,
locs, aux)config_search_loc
() iterates over all potential
children, calling the given function func for each
one. If func is NULL
,
config_search_loc
() applies each child's match
function instead. The argument parent is the pointer
to the parent's device structure. The argument ia is
the interface attribute on which the potential children should attach. It
can be NULL
, in which case all children attaching
to any attribute are considered. The locs argument
lists the locator values for the device and are passed to function
func. The given aux argument
describes the device that has been found and is simply passed on through
func to the child.
config_search_loc
() returns a pointer to the
best-matched child or NULL
otherwise.
The role of func is to call the match
function for each device and call
config_attach_loc
() for any positive matches. If
func is NULL
, then the
parent should record the return value from
config_search_loc
() and call
config_attach_loc
() itself.
Note that this function is designed so that it can be used to apply an arbitrary function to all potential children. In this case callers may choose to ignore the return value.
config_search_ia
(func,
parent, ia,
aux)config_search_loc
(func,
parent, ia,
locs, aux) with
locs set to NULL
.config_found_sm_loc
(parent,
ia, locs,
aux, print,
submatch)config_found_sm_loc
() is called by the parent and
in turn calls the submatch function to call the
match function as determined by the configuration table. If
submatch is NULL
, the driver
match functions are called directly. The argument
parent is the pointer to the parent's device
structure. The argument ia is the name of the
interface attribute on which the child will attach, per
config(5) syntax. The
argument locs lists the locator values for the
device. The given aux argument describes the device
that has been found. config_found_sm_loc
()
internally uses config_search_loc
(), passing on
submatch, ia,
locs and aux. The
softc structure for the matched device will be
allocated, and the appropriate driver attach function will be called. If
the device is matched, the system prints the name of the child and parent
devices, and then calls the print function to
produce additional information if desired. If no driver takes a match, the
same print function is called to complain. The print
function is called with the aux argument and, if the
matches failed, the full name (including unit number) of the parent
device, otherwise NULL
. The
print function must return an integer value.
Two special strings, “not configured” and “unsupported” will be appended automatically to non-driver reports if the return value is UNCONF or UNSUPP respectively; otherwise the function should return the value QUIET.
config_found_sm_loc
() returns a
pointer to the attached device's softc structure if
the device is attached, NULL
otherwise. Most
callers can ignore this value, since the system will already have
printed a diagnostic.
config_found_ia
(parent,
ia, aux,
print)config_found_sm_loc
(parent,
ia, locs,
aux, print,
submatch) with locs and
submatch set to NULL
. It is
provided for better source code readability with locator-less device
buses.config_found
(parent,
aux, print)config_found_sm_loc
(parent,
ia, locs,
aux, print,
submatch) with ia,
locs and submatch set to
NULL
and is provided for compatibility with older
drivers. New code should either make the interface attribute explicit or
prefer an indirect method based on
config_search_loc
().config_match
(parent,
cf, aux)config_match
() function
returns a nonzero integer indicating the confidence of supporting this
device and a value of 0 if the driver doesn't support the device.config_attach_loc
(parent,
cf, locs,
aux, print)config_attach_loc
() returns the
softc. If unsuccessful, it returns
NULL
.config_attach
(parent,
cf, aux,
print)config_attach_loc
(parent,
cf, locs,
aux, print) with
locs set to NULL
.config_attach_pseudo
(cf)The caller is expected to allocate and fill the
cfdata_t object and pass it to
config_attach_pseudo
(). The content of that
object is similar to what is returned by
config_search_loc
() for regular devices.
config_detach
(dev,
flags)config_detach
() returns zero if successful and an
error code otherwise. config_detach
() is always
called from a thread context, allowing condition variables to be used
while the device detaches itself.config_detach_children
(dev,
flags)config_detach
() for each child of
dev, passing flags. If
detaching any child results in an error, the iteration will halt and any
remaining devices will not be detached.
config_detach_children
() returns zero if
successful and an error code otherwise.config_deactivate
(dev)config_deactivate
() is
called from interrupt context to immediately relinquish resources and
notify dependent kernel subsystems that the device is about to be
detached. At some later point config_detach
() will
be called to finalise the removal of the device.config_defer
(dev,
func)config_interrupts
(dev,
func)config_mountroot
(dev,
func)config_pending_incr
()config_pending_decr
()config_finalize_register
(dev,
func)Registered functions are all executed until all of them return 0. The callbacks should return 0 to indicate they do not require to be called another time, but they should be aware that they still might be in case one of them returns 1.
February 17, 2012 | NetBSD 9.2 |