/* * Functions for dealing with DT resolution * * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> * Copyright (C) 2012 Texas Instruments Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. */ #include <linux/kernel.h>#include <linux/module.h>#include <linux/of.h>#include <linux/of_device.h>#include <linux/string.h>#include <linux/ctype.h>#include <linux/errno.h>#include <linux/string.h>#include <linux/slab.h> /* illegal phandle value (set when unresolved) */#define OF_PHANDLE_ILLEGAL	0xdeadbeef /** * Find a node with the give full name by recursively following any of * the child node links. */static struct device_node *__of_find_node_by_full_name(struct device_node *node,		const char *full_name){	struct device_node *child, *found; 	if (node == NULL)		return NULL; 	/* check */	if (of_node_cmp(node->full_name, full_name) == 0)		return node; 	for_each_child_of_node(node, child) {		found = __of_find_node_by_full_name(child, full_name);		if (found != NULL)			return found;	} 	return NULL;} /* * Find live tree's maximum phandle value. */static phandle of_get_tree_max_phandle(void){	struct device_node *node;	phandle phandle;	unsigned long flags; 	/* now search recursively */	raw_spin_lock_irqsave(&devtree_lock, flags);	phandle = 0;	for_each_of_allnodes(node) {		if (node->phandle != OF_PHANDLE_ILLEGAL &&				node->phandle > phandle)			phandle = node->phandle;	}	raw_spin_unlock_irqrestore(&devtree_lock, flags); 	return phandle;} /* * Adjust a subtree's phandle values by a given delta. * Makes sure not to just adjust the device node's phandle value, * but modify the phandle properties values as well. */static void __of_adjust_tree_phandles(struct device_node *node,		int phandle_delta){	struct device_node *child;	struct property *prop;	phandle phandle; 	/* first adjust the node's phandle direct value */	if (node->phandle != 0 && node->phandle != OF_PHANDLE_ILLEGAL)		node->phandle += phandle_delta; 	/* now adjust phandle & linux,phandle values */	for_each_property_of_node(node, prop) { 		/* only look for these two */		if (of_prop_cmp(prop->name, "phandle") != 0 &&		    of_prop_cmp(prop->name, "linux,phandle") != 0)			continue; 		/* must be big enough */		if (prop->length < 4)			continue; 		/* read phandle value */		phandle = be32_to_cpup(prop->value);		if (phandle == OF_PHANDLE_ILLEGAL)	/* unresolved */			continue; 		/* adjust */		*(uint32_t *)prop->value = cpu_to_be32(node->phandle);	} 	/* now do the children recursively */	for_each_child_of_node(node, child)		__of_adjust_tree_phandles(child, phandle_delta);} static int __of_adjust_phandle_ref(struct device_node *node, struct property *rprop, int value, bool is_delta){	phandle phandle;	struct device_node *refnode;	struct property *sprop;	char *propval, *propcur, *propend, *nodestr, *propstr, *s;	int offset, propcurlen;	int err = 0; 	/* make a copy */	propval = kmalloc(rprop->length, GFP_KERNEL);	if (!propval) {		pr_err("%s: Could not copy value of '%s'\n",				__func__, rprop->name);		return -ENOMEM;	}	memcpy(propval, rprop->value, rprop->length); 	propend = propval + rprop->length;	for (propcur = propval; propcur < propend; propcur += propcurlen + 1) {		propcurlen = strlen(propcur); 		nodestr = propcur;		s = strchr(propcur, ':');		if (!s) {			pr_err("%s: Illegal symbol entry '%s' (1)\n",				__func__, propcur);			err = -EINVAL;			goto err_fail;		}		*s++ = '\0'; 		propstr = s;		s = strchr(s, ':');		if (!s) {			pr_err("%s: Illegal symbol entry '%s' (2)\n",				__func__, (char *)rprop->value);			err = -EINVAL;			goto err_fail;		} 		*s++ = '\0';		err = kstrtoint(s, 10, &offset);		if (err != 0) {			pr_err("%s: Could get offset '%s'\n",				__func__, (char *)rprop->value);			goto err_fail;		} 		/* look into the resolve node for the full path */		refnode = __of_find_node_by_full_name(node, nodestr);		if (!refnode) {			pr_warn("%s: Could not find refnode '%s'\n",				__func__, (char *)rprop->value);			continue;		} 		/* now find the property */		for_each_property_of_node(refnode, sprop) {			if (of_prop_cmp(sprop->name, propstr) == 0)				break;		} 		if (!sprop) {			pr_err("%s: Could not find property '%s'\n",				__func__, (char *)rprop->value);			err = -ENOENT;			goto err_fail;		} 		phandle = is_delta ? be32_to_cpup(sprop->value + offset) + value : value;		*(__be32 *)(sprop->value + offset) = cpu_to_be32(phandle);	} err_fail:	kfree(propval);	return err;} /* * Adjust the local phandle references by the given phandle delta. * Assumes the existances of a __local_fixups__ node at the root * of the tree. Does not take any devtree locks so make sure you * call this on a tree which is at the detached state. */static int __of_adjust_tree_phandle_references(struct device_node *node,		int phandle_delta){	struct device_node *child;	struct property *rprop;	int err; 	/* locate the symbols & fixups nodes on resolve */	for_each_child_of_node(node, child)		if (of_node_cmp(child->name, "__local_fixups__") == 0)			break; 	/* no local fixups */	if (!child)		return 0; 	/* find the local fixups property */	for_each_property_of_node(child, rprop) {		/* skip properties added automatically */		if (of_prop_cmp(rprop->name, "name") == 0)			continue; 		err = __of_adjust_phandle_ref(node, rprop, phandle_delta, true);		if (err)			return err;	} 	return 0;} /** * of_resolve	- Resolve the given node against the live tree. * * @resolve:	Node to resolve * * Perform dynamic Device Tree resolution against the live tree * to the given node to resolve. This depends on the live tree * having a __symbols__ node, and the resolve node the __fixups__ & * __local_fixups__ nodes (if needed). * The result of the operation is a resolve node that it's contents * are fit to be inserted or operate upon the live tree. * Returns 0 on success or a negative error value on error. */int of_resolve_phandles(struct device_node *resolve){	struct device_node *child, *refnode;	struct device_node *root_sym, *resolve_sym, *resolve_fix;	struct property *rprop;	const char *refpath;	phandle phandle, phandle_delta;	int err; 	/* the resolve node must exist, and be detached */	if (!resolve || !of_node_check_flag(resolve, OF_DETACHED))		return -EINVAL; 	/* first we need to adjust the phandles */	phandle_delta = of_get_tree_max_phandle() + 1;	__of_adjust_tree_phandles(resolve, phandle_delta);	err = __of_adjust_tree_phandle_references(resolve, phandle_delta);	if (err != 0)		return err; 	root_sym = NULL;	resolve_sym = NULL;	resolve_fix = NULL; 	/* this may fail (if no fixups are required) */	root_sym = of_find_node_by_path("/__symbols__"); 	/* locate the symbols & fixups nodes on resolve */	for_each_child_of_node(resolve, child) { 		if (!resolve_sym &&				of_node_cmp(child->name, "__symbols__") == 0)			resolve_sym = child; 		if (!resolve_fix &&				of_node_cmp(child->name, "__fixups__") == 0)			resolve_fix = child; 		/* both found, don't bother anymore */		if (resolve_sym && resolve_fix)			break;	} 	/* we do allow for the case where no fixups are needed */	if (!resolve_fix) {		err = 0;	/* no error */		goto out;	} 	/* we need to fixup, but no root symbols... */	if (!root_sym) {		err = -EINVAL;		goto out;	} 	for_each_property_of_node(resolve_fix, rprop) { 		/* skip properties added automatically */		if (of_prop_cmp(rprop->name, "name") == 0)			continue; 		err = of_property_read_string(root_sym,				rprop->name, &refpath);		if (err != 0) {			pr_err("%s: Could not find symbol '%s'\n",					__func__, rprop->name);			goto out;		} 		refnode = of_find_node_by_path(refpath);		if (!refnode) {			pr_err("%s: Could not find node by path '%s'\n",					__func__, refpath);			err = -ENOENT;			goto out;		} 		phandle = refnode->phandle;		of_node_put(refnode); 		pr_debug("%s: %s phandle is 0x%08x\n",				__func__, rprop->name, phandle); 		err = __of_adjust_phandle_ref(resolve, rprop, phandle, false);		if (err)			break;	} out:	/* NULL is handled by of_node_put as NOP */	of_node_put(root_sym); 	return err;}EXPORT_SYMBOL_GPL(of_resolve_phandles);