// SPDX-License-Identifier: GPL-2.0 /* * Functions for dealing with DT resolution * * Copyright (C) 2012 Pantelis Antoniou <[email protected]> * Copyright (C) 2012 Texas Instruments Inc. */ #define pr_fmt(fmt) … #include <linux/cleanup.h> #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/slab.h> #include "of_private.h" static phandle live_tree_max_phandle(void) { … } static void adjust_overlay_phandles(struct device_node *overlay, int phandle_delta) { … } static int update_usages_of_a_phandle_reference(struct device_node *overlay, struct property *prop_fixup, phandle phandle) { … } /* compare nodes taking into account that 'name' strips out the @ part */ static int node_name_cmp(const struct device_node *dn1, const struct device_node *dn2) { … } /* * Adjust the local phandle references by the given phandle delta. * * Subtree @local_fixups, which is overlay node __local_fixups__, * mirrors the fragment node structure at the root of the overlay. * * For each property in the fragments that contains a phandle reference, * @local_fixups has a property of the same name that contains a list * of offsets of the phandle reference(s) within the respective property * value(s). The values at these offsets will be fixed up. */ static int adjust_local_phandle_references(struct device_node *local_fixups, struct device_node *overlay, int phandle_delta) { … } /** * of_resolve_phandles - Relocate and resolve overlay against live tree * * @overlay: Pointer to devicetree overlay to relocate and resolve * * Modify (relocate) values of local phandles in @overlay to a range that * does not conflict with the live expanded devicetree. Update references * to the local phandles in @overlay. Update (resolve) phandle references * in @overlay that refer to the live expanded devicetree. * * Phandle values in the live tree are in the range of * 1 .. live_tree_max_phandle(). The range of phandle values in the overlay * also begin with at 1. Adjust the phandle values in the overlay to begin * at live_tree_max_phandle() + 1. Update references to the phandles to * the adjusted phandle values. * * The name of each property in the "__fixups__" node in the overlay matches * the name of a symbol (a label) in the live tree. The values of each * property in the "__fixups__" node is a list of the property values in the * overlay that need to be updated to contain the phandle reference * corresponding to that symbol in the live tree. Update the references in * the overlay with the phandle values in the live tree. * * @overlay must be detached. * * Resolving and applying @overlay to the live expanded devicetree must be * protected by a mechanism to ensure that multiple overlays are processed * in a single threaded manner so that multiple overlays will not relocate * phandles to overlapping ranges. The mechanism to enforce this is not * yet implemented. * * Return: %0 on success or a negative error value on error. */ int of_resolve_phandles(struct device_node *overlay) { … } EXPORT_SYMBOL_GPL(…);
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