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Add ofw_bus_find_child_by_phandle, a helper routine to find a device_t

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child matchig a given phandle_t.

Differential Revision: https://reviews.freebsd.org/D2871
This commit is contained in:
Warner Losh 2015-06-20 04:48:48 +00:00
parent 9308005ed9
commit bb39ff4c36
2 changed files with 44 additions and 0 deletions
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41
sys/dev/ofw/ofw_bus_subr.c
View File

@ -551,3 +551,44 @@ ofw_bus_find_compatible(phandle_t node, const char *onecompat)
}
return (0);
}
/**
* @brief Return child of bus whose phandle is node
*
* A direct child of @p will be returned if it its phandle in the
* OFW tree is @p node. Otherwise, NULL is returned.
*
* @param bus The bus to examine
* @param node The phandle_t to look for.
*/
device_t
ofw_bus_find_child_device_by_phandle(device_t bus, phandle_t node)
{
device_t *children, retval, child;
int nkid, i;
/*
* Nothing can match the flag value for no node.
*/
if (node == -1)
return (NULL);
/*
* Search the children for a match. We microoptimize
* a bit by not using ofw_bus_get since we already know
* the parent. We do not recurse.
*/
if (device_get_children(bus, &children, &nkid) != 0)
return (NULL);
retval = NULL;
for (i = 0; i < nkid; i++) {
child = children[i];
if (OFW_BUS_GET_NODE(bus, child) == node) {
retval = child;
break;
}
}
free(children, M_TEMP);
return (retval);
}

3
sys/dev/ofw/ofw_bus_subr.h
View File

@ -107,4 +107,7 @@ phandle_t ofw_bus_find_compatible(phandle_t, const char *);
/* Helper to search for a child with a given name */
phandle_t ofw_bus_find_child(phandle_t, const char *);
/* Helper routine to find a device_t child matchig a given phandle_t */
device_t ofw_bus_find_child_device_by_phandle(device_t bus, phandle_t node);
#endif /* !_DEV_OFW_OFW_BUS_SUBR_H_ */