677 lines
17 KiB
C
677 lines
17 KiB
C
#include "libfdt_env.h"
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#include <fdt.h>
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#include <libfdt.h>
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#include "libfdt_internal.h"
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/**
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* overlay_get_target_phandle - retrieves the target phandle of a fragment
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* @fdto: pointer to the device tree overlay blob
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* @fragment: node offset of the fragment in the overlay
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*
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* overlay_get_target_phandle() retrieves the target phandle of an
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* overlay fragment when that fragment uses a phandle (target
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* property) instead of a path (target-path property).
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*
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* returns:
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* the phandle pointed by the target property
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* 0, if the phandle was not found
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* -1, if the phandle was malformed
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*/
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static uint32_t overlay_get_target_phandle(const void *fdto, int fragment)
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{
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const uint32_t *val;
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int len;
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val = fdt_getprop(fdto, fragment, "target", &len);
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if (!val)
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return 0;
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if ((len != sizeof(*val)) || (*val == (uint32_t)-1))
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return (uint32_t)-1;
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return fdt32_to_cpu(*val);
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}
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/**
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* overlay_get_target - retrieves the offset of a fragment's target
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* @fdt: Base device tree blob
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* @fdto: Device tree overlay blob
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* @fragment: node offset of the fragment in the overlay
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*
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* overlay_get_target() retrieves the target offset in the base
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* device tree of a fragment, no matter how the actual targetting is
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* done (through a phandle or a path)
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*
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* returns:
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* the targetted node offset in the base device tree
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* Negative error code on error
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*/
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static int overlay_get_target(const void *fdt, const void *fdto,
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int fragment)
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{
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uint32_t phandle;
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const char *path;
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int path_len;
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/* Try first to do a phandle based lookup */
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phandle = overlay_get_target_phandle(fdto, fragment);
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if (phandle == (uint32_t)-1)
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return -FDT_ERR_BADPHANDLE;
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if (phandle)
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return fdt_node_offset_by_phandle(fdt, phandle);
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/* And then a path based lookup */
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path = fdt_getprop(fdto, fragment, "target-path", &path_len);
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if (!path) {
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/*
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* If we haven't found either a target or a
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* target-path property in a node that contains a
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* __overlay__ subnode (we wouldn't be called
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* otherwise), consider it a improperly written
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* overlay
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*/
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if (path_len == -FDT_ERR_NOTFOUND)
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return -FDT_ERR_BADOVERLAY;
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return path_len;
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}
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return fdt_path_offset(fdt, path);
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}
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/**
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* overlay_phandle_add_offset - Increases a phandle by an offset
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* @fdt: Base device tree blob
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* @node: Device tree overlay blob
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* @name: Name of the property to modify (phandle or linux,phandle)
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* @delta: offset to apply
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*
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* overlay_phandle_add_offset() increments a node phandle by a given
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* offset.
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*
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* returns:
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* 0 on success.
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* Negative error code on error
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*/
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static int overlay_phandle_add_offset(void *fdt, int node,
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const char *name, uint32_t delta)
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{
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const uint32_t *val;
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uint32_t adj_val;
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int len;
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val = fdt_getprop(fdt, node, name, &len);
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if (!val)
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return len;
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if (len != sizeof(*val))
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return -FDT_ERR_BADPHANDLE;
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adj_val = fdt32_to_cpu(*val);
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if ((adj_val + delta) < adj_val)
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return -FDT_ERR_NOPHANDLES;
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adj_val += delta;
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if (adj_val == (uint32_t)-1)
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return -FDT_ERR_NOPHANDLES;
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return fdt_setprop_inplace_u32(fdt, node, name, adj_val);
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}
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/**
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* overlay_adjust_node_phandles - Offsets the phandles of a node
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* @fdto: Device tree overlay blob
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* @node: Offset of the node we want to adjust
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* @delta: Offset to shift the phandles of
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*
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* overlay_adjust_node_phandles() adds a constant to all the phandles
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* of a given node. This is mainly use as part of the overlay
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* application process, when we want to update all the overlay
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* phandles to not conflict with the overlays of the base device tree.
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*
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* returns:
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* 0 on success
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* Negative error code on failure
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*/
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static int overlay_adjust_node_phandles(void *fdto, int node,
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uint32_t delta)
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{
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int child;
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int ret;
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ret = overlay_phandle_add_offset(fdto, node, "phandle", delta);
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if (ret && ret != -FDT_ERR_NOTFOUND)
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return ret;
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ret = overlay_phandle_add_offset(fdto, node, "linux,phandle", delta);
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if (ret && ret != -FDT_ERR_NOTFOUND)
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return ret;
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fdt_for_each_subnode(child, fdto, node) {
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ret = overlay_adjust_node_phandles(fdto, child, delta);
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if (ret)
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return ret;
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}
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return 0;
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}
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/**
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* overlay_adjust_local_phandles - Adjust the phandles of a whole overlay
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* @fdto: Device tree overlay blob
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* @delta: Offset to shift the phandles of
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*
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* overlay_adjust_local_phandles() adds a constant to all the
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* phandles of an overlay. This is mainly use as part of the overlay
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* application process, when we want to update all the overlay
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* phandles to not conflict with the overlays of the base device tree.
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*
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* returns:
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* 0 on success
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* Negative error code on failure
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*/
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static int overlay_adjust_local_phandles(void *fdto, uint32_t delta)
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{
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/*
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* Start adjusting the phandles from the overlay root
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*/
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return overlay_adjust_node_phandles(fdto, 0, delta);
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}
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/**
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* overlay_update_local_node_references - Adjust the overlay references
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* @fdto: Device tree overlay blob
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* @tree_node: Node offset of the node to operate on
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* @fixup_node: Node offset of the matching local fixups node
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* @delta: Offset to shift the phandles of
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*
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* overlay_update_local_nodes_references() update the phandles
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* pointing to a node within the device tree overlay by adding a
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* constant delta.
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*
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* This is mainly used as part of a device tree application process,
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* where you want the device tree overlays phandles to not conflict
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* with the ones from the base device tree before merging them.
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*
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* returns:
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* 0 on success
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* Negative error code on failure
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*/
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static int overlay_update_local_node_references(void *fdto,
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int tree_node,
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int fixup_node,
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uint32_t delta)
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{
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int fixup_prop;
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int fixup_child;
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int ret;
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fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) {
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const uint32_t *fixup_val;
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const char *tree_val;
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const char *name;
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int fixup_len;
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int tree_len;
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int i;
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fixup_val = fdt_getprop_by_offset(fdto, fixup_prop,
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&name, &fixup_len);
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if (!fixup_val)
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return fixup_len;
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if (fixup_len % sizeof(uint32_t))
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return -FDT_ERR_BADOVERLAY;
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tree_val = fdt_getprop(fdto, tree_node, name, &tree_len);
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if (!tree_val) {
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if (tree_len == -FDT_ERR_NOTFOUND)
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return -FDT_ERR_BADOVERLAY;
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return tree_len;
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}
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for (i = 0; i < (fixup_len / sizeof(uint32_t)); i++) {
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uint32_t adj_val, poffset;
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poffset = fdt32_to_cpu(fixup_val[i]);
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/*
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* phandles to fixup can be unaligned.
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*
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* Use a memcpy for the architectures that do
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* not support unaligned accesses.
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*/
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memcpy(&adj_val, tree_val + poffset, sizeof(adj_val));
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adj_val = fdt32_to_cpu(adj_val);
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adj_val += delta;
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adj_val = cpu_to_fdt32(adj_val);
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ret = fdt_setprop_inplace_namelen_partial(fdto,
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tree_node,
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name,
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strlen(name),
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poffset,
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&adj_val,
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sizeof(adj_val));
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if (ret == -FDT_ERR_NOSPACE)
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return -FDT_ERR_BADOVERLAY;
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if (ret)
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return ret;
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}
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}
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fdt_for_each_subnode(fixup_child, fdto, fixup_node) {
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const char *fixup_child_name = fdt_get_name(fdto, fixup_child,
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NULL);
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int tree_child;
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tree_child = fdt_subnode_offset(fdto, tree_node,
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fixup_child_name);
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if (ret == -FDT_ERR_NOTFOUND)
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return -FDT_ERR_BADOVERLAY;
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if (tree_child < 0)
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return tree_child;
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ret = overlay_update_local_node_references(fdto,
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tree_child,
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fixup_child,
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delta);
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if (ret)
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return ret;
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}
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return 0;
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}
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/**
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* overlay_update_local_references - Adjust the overlay references
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* @fdto: Device tree overlay blob
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* @delta: Offset to shift the phandles of
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*
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* overlay_update_local_references() update all the phandles pointing
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* to a node within the device tree overlay by adding a constant
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* delta to not conflict with the base overlay.
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*
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* This is mainly used as part of a device tree application process,
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* where you want the device tree overlays phandles to not conflict
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* with the ones from the base device tree before merging them.
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*
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* returns:
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* 0 on success
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* Negative error code on failure
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*/
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static int overlay_update_local_references(void *fdto, uint32_t delta)
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{
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int fixups;
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fixups = fdt_path_offset(fdto, "/__local_fixups__");
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if (fixups < 0) {
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/* There's no local phandles to adjust, bail out */
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if (fixups == -FDT_ERR_NOTFOUND)
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return 0;
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return fixups;
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}
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/*
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* Update our local references from the root of the tree
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*/
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return overlay_update_local_node_references(fdto, 0, fixups,
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delta);
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}
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/**
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* overlay_fixup_one_phandle - Set an overlay phandle to the base one
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* @fdt: Base Device Tree blob
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* @fdto: Device tree overlay blob
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* @symbols_off: Node offset of the symbols node in the base device tree
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* @path: Path to a node holding a phandle in the overlay
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* @path_len: number of path characters to consider
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* @name: Name of the property holding the phandle reference in the overlay
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* @name_len: number of name characters to consider
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* @poffset: Offset within the overlay property where the phandle is stored
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* @label: Label of the node referenced by the phandle
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*
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* overlay_fixup_one_phandle() resolves an overlay phandle pointing to
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* a node in the base device tree.
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*
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* This is part of the device tree overlay application process, when
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* you want all the phandles in the overlay to point to the actual
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* base dt nodes.
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*
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* returns:
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* 0 on success
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* Negative error code on failure
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*/
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static int overlay_fixup_one_phandle(void *fdt, void *fdto,
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int symbols_off,
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const char *path, uint32_t path_len,
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const char *name, uint32_t name_len,
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int poffset, const char *label)
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{
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const char *symbol_path;
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uint32_t phandle;
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int symbol_off, fixup_off;
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int prop_len;
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if (symbols_off < 0)
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return symbols_off;
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symbol_path = fdt_getprop(fdt, symbols_off, label,
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&prop_len);
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if (!symbol_path)
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return prop_len;
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symbol_off = fdt_path_offset(fdt, symbol_path);
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if (symbol_off < 0)
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return symbol_off;
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phandle = fdt_get_phandle(fdt, symbol_off);
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if (!phandle)
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return -FDT_ERR_NOTFOUND;
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fixup_off = fdt_path_offset_namelen(fdto, path, path_len);
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if (fixup_off == -FDT_ERR_NOTFOUND)
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return -FDT_ERR_BADOVERLAY;
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if (fixup_off < 0)
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return fixup_off;
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phandle = cpu_to_fdt32(phandle);
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return fdt_setprop_inplace_namelen_partial(fdto, fixup_off,
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name, name_len, poffset,
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&phandle, sizeof(phandle));
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};
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/**
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* overlay_fixup_phandle - Set an overlay phandle to the base one
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* @fdt: Base Device Tree blob
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* @fdto: Device tree overlay blob
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* @symbols_off: Node offset of the symbols node in the base device tree
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* @property: Property offset in the overlay holding the list of fixups
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*
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* overlay_fixup_phandle() resolves all the overlay phandles pointed
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* to in a __fixups__ property, and updates them to match the phandles
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* in use in the base device tree.
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*
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* This is part of the device tree overlay application process, when
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* you want all the phandles in the overlay to point to the actual
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* base dt nodes.
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*
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* returns:
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* 0 on success
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* Negative error code on failure
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*/
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static int overlay_fixup_phandle(void *fdt, void *fdto, int symbols_off,
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int property)
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{
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const char *value;
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const char *label;
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int len;
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value = fdt_getprop_by_offset(fdto, property,
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&label, &len);
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if (!value) {
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if (len == -FDT_ERR_NOTFOUND)
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return -FDT_ERR_INTERNAL;
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return len;
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}
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do {
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const char *path, *name, *fixup_end;
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const char *fixup_str = value;
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uint32_t path_len, name_len;
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uint32_t fixup_len;
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char *sep, *endptr;
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int poffset, ret;
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fixup_end = memchr(value, '\0', len);
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if (!fixup_end)
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return -FDT_ERR_BADOVERLAY;
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fixup_len = fixup_end - fixup_str;
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len -= fixup_len + 1;
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value += fixup_len + 1;
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path = fixup_str;
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sep = memchr(fixup_str, ':', fixup_len);
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if (!sep || *sep != ':')
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return -FDT_ERR_BADOVERLAY;
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path_len = sep - path;
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if (path_len == (fixup_len - 1))
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return -FDT_ERR_BADOVERLAY;
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fixup_len -= path_len + 1;
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name = sep + 1;
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sep = memchr(name, ':', fixup_len);
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if (!sep || *sep != ':')
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return -FDT_ERR_BADOVERLAY;
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name_len = sep - name;
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if (!name_len)
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return -FDT_ERR_BADOVERLAY;
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poffset = strtoul(sep + 1, &endptr, 10);
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if ((*endptr != '\0') || (endptr <= (sep + 1)))
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return -FDT_ERR_BADOVERLAY;
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ret = overlay_fixup_one_phandle(fdt, fdto, symbols_off,
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path, path_len, name, name_len,
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poffset, label);
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if (ret)
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return ret;
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} while (len > 0);
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return 0;
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}
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/**
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* overlay_fixup_phandles - Resolve the overlay phandles to the base
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* device tree
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* @fdt: Base Device Tree blob
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* @fdto: Device tree overlay blob
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*
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* overlay_fixup_phandles() resolves all the overlay phandles pointing
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* to nodes in the base device tree.
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*
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* This is one of the steps of the device tree overlay application
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* process, when you want all the phandles in the overlay to point to
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* the actual base dt nodes.
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*
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* returns:
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* 0 on success
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* Negative error code on failure
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*/
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static int overlay_fixup_phandles(void *fdt, void *fdto)
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{
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int fixups_off, symbols_off;
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int property;
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/* We can have overlays without any fixups */
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fixups_off = fdt_path_offset(fdto, "/__fixups__");
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if (fixups_off == -FDT_ERR_NOTFOUND)
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return 0; /* nothing to do */
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if (fixups_off < 0)
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return fixups_off;
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/* And base DTs without symbols */
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symbols_off = fdt_path_offset(fdt, "/__symbols__");
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if ((symbols_off < 0 && (symbols_off != -FDT_ERR_NOTFOUND)))
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return symbols_off;
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fdt_for_each_property_offset(property, fdto, fixups_off) {
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int ret;
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ret = overlay_fixup_phandle(fdt, fdto, symbols_off, property);
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if (ret)
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return ret;
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}
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return 0;
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}
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/**
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* overlay_apply_node - Merges a node into the base device tree
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* @fdt: Base Device Tree blob
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* @target: Node offset in the base device tree to apply the fragment to
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* @fdto: Device tree overlay blob
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* @node: Node offset in the overlay holding the changes to merge
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*
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* overlay_apply_node() merges a node into a target base device tree
|
|
* node pointed.
|
|
*
|
|
* This is part of the final step in the device tree overlay
|
|
* application process, when all the phandles have been adjusted and
|
|
* resolved and you just have to merge overlay into the base device
|
|
* tree.
|
|
*
|
|
* returns:
|
|
* 0 on success
|
|
* Negative error code on failure
|
|
*/
|
|
static int overlay_apply_node(void *fdt, int target,
|
|
void *fdto, int node)
|
|
{
|
|
int property;
|
|
int subnode;
|
|
|
|
fdt_for_each_property_offset(property, fdto, node) {
|
|
const char *name;
|
|
const void *prop;
|
|
int prop_len;
|
|
int ret;
|
|
|
|
prop = fdt_getprop_by_offset(fdto, property, &name,
|
|
&prop_len);
|
|
if (prop_len == -FDT_ERR_NOTFOUND)
|
|
return -FDT_ERR_INTERNAL;
|
|
if (prop_len < 0)
|
|
return prop_len;
|
|
|
|
ret = fdt_setprop(fdt, target, name, prop, prop_len);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
fdt_for_each_subnode(subnode, fdto, node) {
|
|
const char *name = fdt_get_name(fdto, subnode, NULL);
|
|
int nnode;
|
|
int ret;
|
|
|
|
nnode = fdt_add_subnode(fdt, target, name);
|
|
if (nnode == -FDT_ERR_EXISTS) {
|
|
nnode = fdt_subnode_offset(fdt, target, name);
|
|
if (nnode == -FDT_ERR_NOTFOUND)
|
|
return -FDT_ERR_INTERNAL;
|
|
}
|
|
|
|
if (nnode < 0)
|
|
return nnode;
|
|
|
|
ret = overlay_apply_node(fdt, nnode, fdto, subnode);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* overlay_merge - Merge an overlay into its base device tree
|
|
* @fdt: Base Device Tree blob
|
|
* @fdto: Device tree overlay blob
|
|
*
|
|
* overlay_merge() merges an overlay into its base device tree.
|
|
*
|
|
* This is the final step in the device tree overlay application
|
|
* process, when all the phandles have been adjusted and resolved and
|
|
* you just have to merge overlay into the base device tree.
|
|
*
|
|
* returns:
|
|
* 0 on success
|
|
* Negative error code on failure
|
|
*/
|
|
static int overlay_merge(void *fdt, void *fdto)
|
|
{
|
|
int fragment;
|
|
|
|
fdt_for_each_subnode(fragment, fdto, 0) {
|
|
int overlay;
|
|
int target;
|
|
int ret;
|
|
|
|
/*
|
|
* Each fragments will have an __overlay__ node. If
|
|
* they don't, it's not supposed to be merged
|
|
*/
|
|
overlay = fdt_subnode_offset(fdto, fragment, "__overlay__");
|
|
if (overlay == -FDT_ERR_NOTFOUND)
|
|
continue;
|
|
|
|
if (overlay < 0)
|
|
return overlay;
|
|
|
|
target = overlay_get_target(fdt, fdto, fragment);
|
|
if (target < 0)
|
|
return target;
|
|
|
|
ret = overlay_apply_node(fdt, target, fdto, overlay);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int fdt_overlay_apply(void *fdt, void *fdto)
|
|
{
|
|
uint32_t delta = fdt_get_max_phandle(fdt);
|
|
int ret;
|
|
|
|
FDT_CHECK_HEADER(fdt);
|
|
FDT_CHECK_HEADER(fdto);
|
|
|
|
ret = overlay_adjust_local_phandles(fdto, delta);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = overlay_update_local_references(fdto, delta);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = overlay_fixup_phandles(fdt, fdto);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = overlay_merge(fdt, fdto);
|
|
if (ret)
|
|
goto err;
|
|
|
|
/*
|
|
* The overlay has been damaged, erase its magic.
|
|
*/
|
|
fdt_set_magic(fdto, ~0);
|
|
|
|
return 0;
|
|
|
|
err:
|
|
/*
|
|
* The overlay might have been damaged, erase its magic.
|
|
*/
|
|
fdt_set_magic(fdto, ~0);
|
|
|
|
/*
|
|
* The base device tree might have been damaged, erase its
|
|
* magic.
|
|
*/
|
|
fdt_set_magic(fdt, ~0);
|
|
|
|
return ret;
|
|
}
|