* [PATCH 2/2] of: implement overlay support
2013-10-14 16:24 [PATCH 1/2] of: simplify phandle lookup Jan Luebbe
@ 2013-10-14 16:24 ` Jan Luebbe
0 siblings, 0 replies; 2+ messages in thread
From: Jan Luebbe @ 2013-10-14 16:24 UTC (permalink / raw)
To: barebox
This implements device tree overlay support as described in
http://thread.gmane.org/gmane.linux.ports.arm.omap/91556 and used
on BeagleBone boards. It can be used to load DT overlays at runtime,
which are then passed as a resolved tree to the kernel.
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
---
commands/oftree.c | 59 ++++++++-
drivers/of/Kconfig | 6 +
drivers/of/Makefile | 1 +
drivers/of/overlay.c | 272 +++++++++++++++++++++++++++++++++++++++
drivers/of/resolver.c | 345 ++++++++++++++++++++++++++++++++++++++++++++++++++
include/of.h | 71 +++++++++++
6 files changed, 752 insertions(+), 2 deletions(-)
create mode 100644 drivers/of/overlay.c
create mode 100644 drivers/of/resolver.c
diff --git a/commands/oftree.c b/commands/oftree.c
index 475f019..7c55edf 100644
--- a/commands/oftree.c
+++ b/commands/oftree.c
@@ -50,11 +50,14 @@ static int do_oftree(int argc, char *argv[])
int probe = 0;
int load = 0;
int save = 0;
+ int overlay = 0;
int free_of = 0;
int ret;
struct device_node *n, *root;
+ int ovinfo_cnt;
+ struct of_overlay_info *ovinfo;
- while ((opt = getopt(argc, argv, "dpfn:ls")) > 0) {
+ while ((opt = getopt(argc, argv, "dpfn:los")) > 0) {
switch (opt) {
case 'l':
load = 1;
@@ -79,6 +82,9 @@ static int do_oftree(int argc, char *argv[])
case 's':
save = 1;
break;
+ case 'o':
+ overlay = 1;
+ break;
}
}
@@ -94,7 +100,7 @@ static int do_oftree(int argc, char *argv[])
if (optind < argc)
file = argv[optind];
- if (!dump && !probe && !load && !save)
+ if (!dump && !probe && !load && !save && !overlay)
return COMMAND_ERROR_USAGE;
if (save) {
@@ -153,6 +159,54 @@ static int do_oftree(int argc, char *argv[])
}
}
+ if (overlay) {
+ if (!fdt) {
+ printf("no fdt given\n");
+ ret = -ENOENT;
+
+ goto out;
+ }
+
+ root = of_get_root_node();
+ if (!root) {
+ printf("no oftree loaded\n");
+ goto out;
+ }
+
+ n = of_unflatten_dtb(NULL, fdt);
+ if (IS_ERR(n))
+ ret = PTR_ERR(n);
+ else
+ ret = 0;
+ if (ret) {
+ printf("parse oftree: %s\n", strerror(-ret));
+ goto out;
+ }
+
+ ret = of_resolve(n);
+ if (ret) {
+ printf("resolve oftree overlay: %s\n", strerror(-ret));
+ of_delete_node(n);
+ goto out;
+ }
+
+ ret = of_build_overlay_info(n, &ovinfo_cnt, &ovinfo);
+ if (ret) {
+ printf("prepare oftree overlay: %s\n", strerror(-ret));
+ of_delete_node(n);
+ goto out;
+ }
+
+ ret = of_overlay(ovinfo_cnt, ovinfo);
+ if (ret) {
+ printf("apply oftree overlay: %s\n", strerror(-ret));
+ of_delete_node(n);
+ goto out;
+ }
+
+ of_delete_node(n);
+ }
+
if (dump) {
if (fdt) {
root = of_unflatten_dtb(NULL, fdt);
@@ -194,6 +248,7 @@ out:
BAREBOX_CMD_HELP_START(oftree)
BAREBOX_CMD_HELP_USAGE("oftree [OPTIONS] [DTB]\n")
BAREBOX_CMD_HELP_OPT ("-l", "Load [DTB] to internal devicetree\n")
+BAREBOX_CMD_HELP_OPT ("-o", "Overlay [DTB] to internal devicetree\n")
BAREBOX_CMD_HELP_OPT ("-p", "probe devices from stored devicetree\n")
BAREBOX_CMD_HELP_OPT ("-d", "dump oftree from [DTB] or the parsed tree if no dtb is given\n")
BAREBOX_CMD_HELP_OPT ("-f", "free stored devicetree\n")
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 6b893d7..fb2c480 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -7,6 +7,12 @@ config OFTREE_MEM_GENERIC
depends on PPC || ARM
def_bool y
+config OFTREE_OVERLAY
+ bool "OF tree overlay support"
+ depends on OFTREE
+ help
+ Allows you to modify the live tree using overlays.
+
config DTC
bool
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index a19a8af..f56db61 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -5,3 +5,4 @@ obj-y += partition.o
obj-y += of_net.o
obj-$(CONFIG_MTD) += of_mtd.o
obj-$(CONFIG_OF_BAREBOX_DRIVERS) += barebox.o of_path.o
+obj-$(CONFIG_OFTREE_OVERLAY) += resolver.o overlay.o
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
new file mode 100644
index 0000000..8e5a705
--- /dev/null
+++ b/drivers/of/overlay.c
@@ -0,0 +1,272 @@
+/*
+ * Functions for working with device tree overlays
+ *
+ * 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 <common.h>
+#include <of.h>
+#include <errno.h>
+#include <malloc.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+#include <linux/err.h>
+
+/**
+ * Apply a single overlay node recursively.
+ *
+ * Property or node names that start with '-' signal that
+ * the property/node is to be removed.
+ *
+ * All the property notifiers are appropriately called.
+ * Note that the in case of an error the target node is left
+ * in a inconsistent state. Error recovery should be performed
+ * by recording the modification using the of notifiers.
+ */
+static int of_overlay_apply_one(struct device_node *target,
+ const struct device_node *overlay)
+{
+ const char *pname, *cname;
+ struct device_node *child, *tchild;
+ struct property *prop;
+ int remove;
+ const char *suffix;
+ int ret;
+
+ /* sanity checks */
+ if (target == NULL || overlay == NULL)
+ return -EINVAL;
+
+ for_each_property_of_node(overlay, prop) {
+ /* don't touch, 'name' */
+ if (of_prop_cmp(prop->name, "name") == 0)
+ continue;
+
+ /* default is add */
+ remove = 0;
+ pname = prop->name;
+ if (*pname == '-') { /* skip, - notes removal */
+ pname++;
+ remove = 1;
+ }
+
+ of_delete_property(of_find_property(target, pname, NULL));
+
+ /* found? */
+ if (remove)
+ continue;
+
+ if (of_new_property(target, pname, prop->value, prop->length) == NULL)
+ return -ENOMEM;
+ }
+
+ for_each_child_of_node(overlay, child) {
+ /* default is add */
+ remove = 0;
+ cname = child->name;
+ if (*cname == '-') { /* skip, - notes removal */
+ cname++;
+ remove = 1;
+ }
+
+ /* special case for nodes with a suffix */
+ suffix = strrchr(child->full_name, '@');
+ if (suffix != NULL) {
+ cname = child->name;
+ WARN_ON(cname == NULL); /* sanity check */
+ if (cname == NULL)
+ continue;
+ if (*cname == '-')
+ cname++;
+ }
+
+ tchild = of_get_child_by_name(target, cname);
+ if (tchild != NULL) {
+ if (!remove) {
+ /* apply overlay recursively */
+ ret = of_overlay_apply_one(tchild, child);
+
+ if (ret != 0)
+ return ret;
+ } else {
+ of_delete_node(tchild);
+ }
+ } else {
+ if (!remove) {
+ /* create new child */
+ tchild = of_new_node(target, cname);
+ if (tchild == NULL)
+ return -ENOMEM;
+
+ /* apply the overlay */
+ ret = of_overlay_apply_one(tchild, child);
+ if (ret != 0) {
+ of_delete_node(tchild);
+ return ret;
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * of_overlay - Apply @count overlays pointed at by @ovinfo_tab
+ * @count: Number of of_overlay_info's
+ * @ovinfo_tab: Array of overlay_info's to apply
+ *
+ * Applies the overlays given, while handling all error conditions
+ * appropriately. Either the operation succeeds, or if it fails the
+ * live tree is reverted to the state before the attempt.
+ * Returns 0, or an error if the overlay attempt failed.
+ */
+int of_overlay(int count, struct of_overlay_info *ovinfo_tab)
+{
+ struct of_overlay_info *ovinfo;
+ int i, err;
+
+ if (!ovinfo_tab)
+ return -EINVAL;
+
+ for (i = 0; i < count; i++) {
+ ovinfo = &ovinfo_tab[i];
+ err = of_overlay_apply_one(ovinfo->target, ovinfo->overlay);
+ if (err != 0) {
+ pr_err("%s: overlay failed '%s'\n",
+ __func__, ovinfo->target->full_name);
+ goto err_fail;
+ }
+ }
+
+ return 0;
+
+err_fail:
+ return err;
+}
+
+/**
+ * of_fill_overlay_info - Fill an overlay info structure
+ * @info_node: Device node containing the overlay
+ * @ovinfo: Pointer to the overlay info structure to fill
+ *
+ * Fills an overlay info structure with the overlay information
+ * from a device node. This device node must have a target property
+ * which contains a phandle of the overlay target node, and an
+ * __overlay__ child node which has the overlay contents.
+ * Both ovinfo->target & ovinfo->overlay have their references taken.
+ *
+ * Returns 0 on success, or a negative error value.
+ */
+int of_fill_overlay_info(struct device_node *info_node,
+ struct of_overlay_info *ovinfo)
+{
+ u32 val;
+ int ret;
+
+ if (!info_node || !ovinfo)
+ return -EINVAL;
+
+ ret = of_property_read_u32(info_node, "target", &val);
+ if (ret != 0)
+ goto err_fail;
+
+ ovinfo->target = of_find_node_by_phandle(val);
+ if (ovinfo->target == NULL)
+ goto err_fail;
+
+ ovinfo->overlay = of_get_child_by_name(info_node, "__overlay__");
+ if (ovinfo->overlay == NULL)
+ goto err_fail;
+
+ return 0;
+
+err_fail:
+ memset(ovinfo, 0, sizeof(*ovinfo));
+ return -EINVAL;
+}
+
+/**
+ * of_build_overlay_info - Build an overlay info array
+ * @tree: Device node containing all the overlays
+ * @cntp: Pointer to where the overlay info count will be help
+ * @ovinfop: Pointer to the pointer of an overlay info structure.
+ *
+ * Helper function that given a tree containing overlay information,
+ * allocates and builds an overlay info array containing it, ready
+ * for use using of_overlay.
+ *
+ * Returns 0 on success with the @cntp @ovinfop pointers valid,
+ * while on error a negative error value is returned.
+ */
+int of_build_overlay_info(struct device_node *tree,
+ int *cntp, struct of_overlay_info **ovinfop)
+{
+ struct device_node *node;
+ struct of_overlay_info *ovinfo;
+ int cnt, err;
+
+ if (tree == NULL || cntp == NULL || ovinfop == NULL)
+ return -EINVAL;
+
+ /* worst case; every child is a node */
+ cnt = 0;
+ for_each_child_of_node(tree, node)
+ cnt++;
+
+ ovinfo = kzalloc(cnt * sizeof(*ovinfo), GFP_KERNEL);
+ if (ovinfo == NULL)
+ return -ENOMEM;
+
+ cnt = 0;
+ for_each_child_of_node(tree, node) {
+ memset(&ovinfo[cnt], 0, sizeof(*ovinfo));
+ err = of_fill_overlay_info(node, &ovinfo[cnt]);
+ if (err == 0)
+ cnt++;
+ }
+
+ /* if nothing filled, return error */
+ if (cnt == 0) {
+ kfree(ovinfo);
+ return -ENODEV;
+ }
+
+ *cntp = cnt;
+ *ovinfop = ovinfo;
+
+ return 0;
+}
+
+/**
+ * of_free_overlay_info - Free an overlay info array
+ * @count: Number of of_overlay_info's
+ * @ovinfo_tab: Array of overlay_info's to free
+ *
+ * Releases the memory of a previously allocate ovinfo array
+ * by of_build_overlay_info.
+ * Returns 0, or an error if the arguments are bogus.
+ */
+int of_free_overlay_info(int count, struct of_overlay_info *ovinfo_tab)
+{
+ struct of_overlay_info *ovinfo;
+ int i;
+
+ if (!ovinfo_tab || count < 0)
+ return -EINVAL;
+
+ /* do it in reverse */
+ for (i = count - 1; i >= 0; i--) {
+ ovinfo = &ovinfo_tab[i];
+ }
+ kfree(ovinfo_tab);
+
+ return 0;
+}
diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
new file mode 100644
index 0000000..3a4367b
--- /dev/null
+++ b/drivers/of/resolver.c
@@ -0,0 +1,345 @@
+/*
+ * 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 <common.h>
+#include <of.h>
+#include <errno.h>
+#include <malloc.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+
+/**
+ * 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_cpu(*(uint32_t *)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);
+}
+
+/**
+ * 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)
+{
+ phandle phandle;
+ struct device_node *refnode, *child;
+ struct property *rprop, *sprop;
+ char *propval, *propcur, *propend, *nodestr, *propstr, *s;
+ int offset, propcurlen;
+ int err;
+ bool found = false;
+
+ /* locate the symbols & fixups nodes on resolve */
+ for_each_child_of_node(node, child)
+ if (of_node_cmp(child->name, "__local_fixups__") == 0) {
+ found = true;
+ break;
+ }
+
+ /* no local fixups */
+ if (!found)
+ 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;
+
+ /* make a copy */
+ propval = kmalloc(rprop->length, GFP_KERNEL);
+ if (propval == NULL) {
+ 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 == NULL) {
+ 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 == NULL) {
+ pr_err("%s: Illegal symbol entry '%s' (2)\n",
+ __func__, (char *)rprop->value);
+ err = -EINVAL;
+ goto err_fail;
+ }
+
+ *s++ = '\0';
+ offset = simple_strtoul(s, NULL, 10);
+
+ /* look into the resolve node for the full path */
+ refnode = of_find_node_by_path_from(node, nodestr);
+ if (refnode == NULL) {
+ pr_warn("%s: Could not find refnode '%s'\n",
+ __func__, (char *)rprop->value);
+ continue;
+ }
+
+ /* now find the property */
+ found = false;
+ for_each_property_of_node(refnode, sprop)
+ if (of_prop_cmp(sprop->name, propstr) == 0) {
+ found = true;
+ break;
+ }
+
+ if (!found) {
+ pr_err("%s: Could not find property '%s'\n",
+ __func__, (char *)rprop->value);
+ err = -ENOENT;
+ goto err_fail;
+ }
+
+ phandle = be32_to_cpu(*(uint32_t *)
+ (sprop->value + offset));
+ *(uint32_t *)(sprop->value + offset) =
+ cpu_to_be32(phandle + phandle_delta);
+ }
+
+ kfree(propval);
+ }
+
+ return 0;
+
+err_fail:
+ kfree(propval);
+ return err;
+}
+
+/**
+ * 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(struct device_node *resolve)
+{
+ struct device_node *child, *refnode;
+ struct device_node *root_sym, *resolve_sym, *resolve_fix;
+ struct property *rprop, *sprop;
+ const char *refpath;
+ char *propval, *propcur, *propend, *nodestr, *propstr, *s;
+ int offset, propcurlen;
+ phandle phandle, phandle_delta;
+ int err;
+ bool found = false;
+
+ /* the resolve node must exist, and be detached */
+ if (resolve == NULL) {
+ return -EINVAL;
+ }
+
+ /* first we need to adjust the phandles */
+ phandle_delta = of_get_tree_max_phandle(NULL) + 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 == NULL &&
+ of_node_cmp(child->name, "__symbols__") == 0)
+ resolve_sym = child;
+
+ if (resolve_fix == NULL &&
+ of_node_cmp(child->name, "__fixups__") == 0)
+ resolve_fix = child;
+
+ /* both found, don't bother anymore */
+ if (resolve_sym != NULL && resolve_fix != NULL)
+ break;
+ }
+
+ /* we do allow for the case where no fixups are needed */
+ if (resolve_fix == NULL)
+ goto merge_sym;
+
+ /* we need to fixup, but no root symbols... */
+ if (root_sym == NULL)
+ return -EINVAL;
+
+ 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 err_fail;
+ }
+
+ refnode = of_find_node_by_path(refpath);
+ if (refnode == NULL) {
+ pr_err("%s: Could not find node by path '%s'\n",
+ __func__, refpath);
+ err = -ENOENT;
+ goto err_fail;
+ }
+
+ phandle = refnode->phandle;
+
+ pr_debug("%s: %s phandle is 0x%08x\n",
+ __func__, rprop->name, phandle);
+
+ /* make a copy */
+ propval = kmalloc(rprop->length, GFP_KERNEL);
+ if (propval == NULL) {
+ pr_err("%s: Could not copy value of '%s'\n",
+ __func__, rprop->name);
+ err = -ENOMEM;
+ goto err_fail;
+ }
+
+ 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 == NULL) {
+ pr_err("%s: Illegal symbol "
+ "entry '%s' (1)\n",
+ __func__, (char *)rprop->value);
+ kfree(propval);
+ err = -EINVAL;
+ goto err_fail;
+ }
+ *s++ = '\0';
+
+ propstr = s;
+ s = strchr(s, ':');
+ if (s == NULL) {
+ pr_err("%s: Illegal symbol "
+ "entry '%s' (2)\n",
+ __func__, (char *)rprop->value);
+ kfree(propval);
+ err = -EINVAL;
+ goto err_fail;
+ }
+
+ *s++ = '\0';
+ offset = simple_strtoul(s, NULL, 10);
+
+ /* look into the resolve node for the full path */
+ refnode = of_find_node_by_path_from(resolve, nodestr);
+ if (refnode == NULL) {
+ pr_err("%s: Could not find refnode '%s'\n",
+ __func__, (char *)rprop->value);
+ kfree(propval);
+ err = -ENOENT;
+ goto err_fail;
+ }
+
+ /* now find the property */
+ found = false;
+ for_each_property_of_node(refnode, sprop)
+ if (of_prop_cmp(sprop->name, propstr) == 0) {
+ found = true;
+ break;
+ }
+
+ if (!found) {
+ pr_err("%s: Could not find property '%s'\n",
+ __func__, (char *)rprop->value);
+ kfree(propval);
+ err = -ENOENT;
+ goto err_fail;
+ }
+
+ *(uint32_t *)(sprop->value + offset) =
+ cpu_to_be32(phandle);
+ }
+
+ kfree(propval);
+ }
+
+merge_sym:
+ return 0;
+
+err_fail:
+ return err;
+}
diff --git a/include/of.h b/include/of.h
index 3381e69..ea55669 100644
--- a/include/of.h
+++ b/include/of.h
@@ -592,6 +592,8 @@ static inline struct device_node *of_find_matching_node(
#define for_each_available_child_of_node(parent, child) \
for (child = of_get_next_available_child(parent, NULL); child != NULL; \
child = of_get_next_available_child(parent, child))
+#define for_each_property_of_node(dn, pp) \
+ list_for_each_entry(pp, &dn->properties, list)
/**
* of_property_read_bool - Findfrom a property
@@ -704,4 +706,73 @@ static inline struct device_node *of_find_root_node(struct device_node *node)
return node;
}
+
+/* illegal phandle value (set when unresolved) */
+#define OF_PHANDLE_ILLEGAL 0xdeadbeef
+
+#ifdef CONFIG_OFTREE_OVERLAY
+
+extern int of_resolve(struct device_node *resolve);
+
+#else
+
+static inline int of_resolve(struct device_node *resolve)
+{
+ return -ENOSYS;
+}
+
+#endif
+
+/**
+ * Overlay support
+ */
+
+/**
+ * struct of_overlay_info - Holds a single overlay info
+ * @target: target of the overlay operation
+ * @overlay: pointer to the overlay contents node
+ *
+ * Holds a single overlay state.
+ */
+struct of_overlay_info {
+ struct device_node *target;
+ struct device_node *overlay;
+};
+
+#ifdef CONFIG_OFTREE_OVERLAY
+
+extern int of_overlay(int count, struct of_overlay_info *ovinfo_tab);
+
+extern int of_fill_overlay_info(struct device_node *info_node,
+ struct of_overlay_info *ovinfo);
+extern int of_build_overlay_info(struct device_node *tree,
+ int *cntp, struct of_overlay_info **ovinfop);
+extern int of_free_overlay_info(int cnt, struct of_overlay_info *ovinfo);
+
+#else
+
+static inline int of_overlay(int count, struct of_overlay_info *ovinfo_tab)
+{
+ return -ENOSYS;
+}
+
+static inline int of_fill_overlay_info(struct device_node *info_node,
+ struct of_overlay_info *ovinfo)
+{
+ return -ENOSYS;
+}
+
+static inline int of_build_overlay_info(struct device_node *tree,
+ int *cntp, struct of_overlay_info **ovinfop)
+{
+ return -ENOSYS;
+}
+
+static inline int of_free_overlay_info(int cnt, struct of_overlay_info *ovinfo)
+{
+ return -ENOSYS;
+}
+
+#endif
+
#endif /* __OF_H */
--
1.8.4.rc3
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