e679c5f445
This requires creating dummy of_node_{get,put} routines for sparc and
sparc64. It also adds a read_lock around the parent accesses.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
137 lines
3.1 KiB
C
137 lines
3.1 KiB
C
/*
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* Procedures for creating, accessing and interpreting the device tree.
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*
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* Paul Mackerras August 1996.
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* Copyright (C) 1996-2005 Paul Mackerras.
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*
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* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
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* {engebret|bergner}@us.ibm.com
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*
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* Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
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*
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* Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/spinlock.h>
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/* use when traversing tree through the allnext, child, sibling,
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* or parent members of struct device_node.
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*/
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DEFINE_RWLOCK(devtree_lock);
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int of_n_addr_cells(struct device_node *np)
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{
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const int *ip;
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do {
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if (np->parent)
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np = np->parent;
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ip = of_get_property(np, "#address-cells", NULL);
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if (ip)
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return *ip;
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} while (np->parent);
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/* No #address-cells property for the root node */
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return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
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}
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EXPORT_SYMBOL(of_n_addr_cells);
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int of_n_size_cells(struct device_node *np)
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{
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const int *ip;
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do {
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if (np->parent)
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np = np->parent;
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ip = of_get_property(np, "#size-cells", NULL);
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if (ip)
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return *ip;
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} while (np->parent);
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/* No #size-cells property for the root node */
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return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
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}
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EXPORT_SYMBOL(of_n_size_cells);
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struct property *of_find_property(const struct device_node *np,
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const char *name,
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int *lenp)
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{
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struct property *pp;
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read_lock(&devtree_lock);
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for (pp = np->properties; pp != 0; pp = pp->next) {
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if (of_prop_cmp(pp->name, name) == 0) {
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if (lenp != 0)
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*lenp = pp->length;
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break;
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}
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}
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read_unlock(&devtree_lock);
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return pp;
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}
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EXPORT_SYMBOL(of_find_property);
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/*
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* Find a property with a given name for a given node
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* and return the value.
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*/
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const void *of_get_property(const struct device_node *np, const char *name,
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int *lenp)
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{
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struct property *pp = of_find_property(np, name, lenp);
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return pp ? pp->value : NULL;
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}
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EXPORT_SYMBOL(of_get_property);
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/** Checks if the given "compat" string matches one of the strings in
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* the device's "compatible" property
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*/
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int of_device_is_compatible(const struct device_node *device,
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const char *compat)
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{
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const char* cp;
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int cplen, l;
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cp = of_get_property(device, "compatible", &cplen);
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if (cp == NULL)
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return 0;
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while (cplen > 0) {
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if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
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return 1;
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l = strlen(cp) + 1;
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cp += l;
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cplen -= l;
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}
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return 0;
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}
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EXPORT_SYMBOL(of_device_is_compatible);
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/**
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* of_get_parent - Get a node's parent if any
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* @node: Node to get parent
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*
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* Returns a node pointer with refcount incremented, use
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* of_node_put() on it when done.
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*/
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struct device_node *of_get_parent(const struct device_node *node)
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{
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struct device_node *np;
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if (!node)
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return NULL;
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read_lock(&devtree_lock);
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np = of_node_get(node->parent);
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read_unlock(&devtree_lock);
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return np;
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}
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EXPORT_SYMBOL(of_get_parent);
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