Add a basic assortment of functions to access the live device tree.
Signed-off-by: Simon Glass <sjg(a)chromium.org>
---
include/dm/of_access.h | 164 +++++++++++++++++++++++++
lib/Makefile | 1 +
lib/of_access.c | 328 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 493 insertions(+)
create mode 100644 include/dm/of_access.h
create mode 100644 lib/of_access.c
diff --git a/include/dm/of_access.h b/include/dm/of_access.h
new file mode 100644
index 00000000000..9a157d8a5b7
--- /dev/null
+++ b/include/dm/of_access.h
@@ -0,0 +1,164 @@
+/*
+ * Originally from Linux v4.9
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
+ * Updates for SPARC64 by David S. Miller
+ * Derived from PowerPC and Sparc prom.h files by Stephen Rothwell, IBM Corp.
+ *
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg(a)chromium.org>
+ *
+ * Modified for U-Boot
+ * Copyright (c) 2017 Google, Inc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifndef _DM_OF_ACCESS_H
+#define _DM_OF_ACCESS_H
+
+#include <dm/of.h>
+
+/**
+ * of_find_all_nodes - Get next node in global list
+ * @prev: Previous node or NULL to start iteration
+ * of_node_put() will be called on it
+ *
+ * Returns a node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_all_nodes(struct device_node *prev);
+
+#define for_each_of_allnodes_from(from, dn) \
+ for (dn = __of_find_all_nodes(from); dn; dn = __of_find_all_nodes(dn))
+#define for_each_of_allnodes(dn) for_each_of_allnodes_from(NULL, dn)
+
+/* Dummy functions to mirror Linux. These are not yet used in U-Boot */
+static inline struct device_node *of_node_get(struct device_node *node)
+{
+ return node;
+}
+
+static inline void of_node_put(struct device_node *node) { }
+
+/**
+ * of_find_property() - find a property in a node
+ *
+ * @np: Pointer to device node holding property
+ * @name: Name of property
+ * @lenp: If non-NULL, returns length of property
+ * @return pointer to property, or NULL if not found
+ */
+struct property *of_find_property(const struct device_node *np,
+ const char *name, int *lenp);
+
+/*
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+const void *of_get_property(const struct device_node *np, const char *name,
+ int *lenp);
+
+/**
+ * of_device_is_available - check if a device is available for use
+ *
+ * @device: Node to check for availability, with locks already held
+ *
+ * Returns true if the status property is absent or set to "okay" or "ok",
+ * false otherwise
+ */
+bool of_device_is_available(const struct device_node *device);
+
+/**
+ * of_find_node_by_phandle - Find a node given a phandle
+ * @handle: phandle of the node to find
+ *
+ * Returns a node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_phandle(phandle handle);
+
+/**
+ * of_parse_phandle - Resolve a phandle property to a device_node pointer
+ * @np: Pointer to device node holding phandle property
+ * @phandle_name: Name of property holding a phandle value
+ * @index: For properties holding a table of phandles, this is the index into
+ * the table
+ *
+ * Returns the device_node pointer with refcount incremented. Use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_parse_phandle(const struct device_node *np,
+ const char *phandle_name, int index);
+
+/**
+ * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
+ * @np: pointer to a device tree node containing a list
+ * @list_name: property name that contains a list
+ * @cells_name: property name that specifies phandles' arguments count
+ * @index: index of a phandle to parse out
+ * @out_args: optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills out_args, on error returns appropriate
+ * errno value.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->np
+ * pointer.
+ *
+ * Example:
+ *
+ * phandle1: node1 {
+ * #list-cells = <2>;
+ * }
+ *
+ * phandle2: node2 {
+ * #list-cells = <1>;
+ * }
+ *
+ * node3 {
+ * list = <&phandle1 1 2 &phandle2 3>;
+ * }
+ *
+ * To get a device_node of the `node2' node you may call this:
+ * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
+ */
+int of_parse_phandle_with_args(const struct device_node *np,
+ const char *list_name, const char *cells_name,
+ int index, struct of_phandle_args *out_args);
+
+/**
+ * of_read_u32() - Find and read a 32-bit integer from a property
+ * @np: device node from which the property value is to be read.
+ * @propname: name of the property to be searched.
+ * @outp: pointer to return value, modified only if return value is 0.
+ *
+ * Search for a property in a device node and read a 32-bit value from
+ * it. Returns 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u64 value can be decoded.
+ */
+int of_read_u32(const struct device_node *np, const char *propname, u32 *outp);
+
+/**
+ * of_read_u32_array() - Find and read an array of 32 bit integers
+ *
+ * @np: device node from which the property value is to be read.
+ * @propname: name of the property to be searched.
+ * @out_values: pointer to return value, modified only if return value is 0.
+ * @sz: number of array elements to read
+ * @return 0 on success, -EINVAL if the property does not exist, -ENODATA
+ * if property does not have a value, and -EOVERFLOW is longer than sz.
+ *
+ * Search for a property in a device node and read 32-bit value(s) from
+ * it.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+int of_read_u32_array(const struct device_node *np, const char *propname,
+ u32 *out_values, size_t sz);
+
+#endif
diff --git a/lib/Makefile b/lib/Makefile
index 23e9f1ef11d..d07a062483a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_ZLIB) += zlib/
obj-$(CONFIG_BZIP2) += bzip2/
obj-$(CONFIG_TIZEN) += tizen/
obj-$(CONFIG_FIT) += libfdt/
+obj-$(CONFIG_OF_LIVE) += of_access.o
obj-$(CONFIG_CMD_DHRYSTONE) += dhry/
obj-$(CONFIG_AES) += aes.o
diff --git a/lib/of_access.c b/lib/of_access.c
new file mode 100644
index 00000000000..e3ffb21dc8a
--- /dev/null
+++ b/lib/of_access.c
@@ -0,0 +1,328 @@
+/*
+ * Originally from Linux v4.9
+ * Paul Mackerras August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ * {engebret|bergner}(a)us.ibm.com
+ *
+ * Adapted for sparc and sparc64 by David S. Miller davem(a)davemloft.net
+ *
+ * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
+ * Grant Likely.
+ *
+ * Modified for U-Boot
+ * Copyright (c) 2017 Google, Inc
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <libfdt.h>
+#include <dm/of_access.h>
+#include <linux/err.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static inline int np_to_offset(const struct device_node *np)
+{
+ return (ulong)np - (ulong)gd->fdt_blob;
+}
+
+struct property *of_find_property(const struct device_node *np,
+ const char *name, int *lenp)
+{
+ struct property *pp;
+
+ if (!np)
+ return NULL;
+
+ for (pp = np->properties; pp; pp = pp->next) {
+ if (strcmp(pp->name, name) == 0) {
+ if (lenp)
+ *lenp = pp->length;
+ break;
+ }
+ }
+
+ return pp;
+}
+
+struct device_node *__of_find_all_nodes(struct device_node *prev)
+{
+ struct device_node *np;
+ if (!prev) {
+ np = gd->of_root;
+ } else if (prev->child) {
+ np = prev->child;
+ } else {
+ /*
+ * Walk back up looking for a sibling, or the end of the
+ * structure
+ */
+ np = prev;
+ while (np->parent && !np->sibling)
+ np = np->parent;
+ np = np->sibling; /* Might be null at the end of the tree */
+ }
+ return np;
+}
+
+struct device_node *of_find_all_nodes(struct device_node *prev)
+{
+ struct device_node *np;
+
+ np = __of_find_all_nodes(prev);
+ of_node_get(np);
+ of_node_put(prev);
+ return np;
+}
+
+/**
+ * of_find_property_value_of_size
+ *
+ * Search for a property in a device node and valid the requested size.
+ *
+ * @np: device node from which the property value is to be read.
+ * @propname: name of the property to be searched.
+ * @len: requested length of property value
+ *
+ * @returns the property value on success, -EINVAL if the property does not
+ * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ */
+static void *of_find_property_value_of_size(const struct device_node *np,
+ const char *propname, u32 len)
+{
+ struct property *prop = of_find_property(np, propname, NULL);
+
+ if (!prop)
+ return ERR_PTR(-EINVAL);
+ if (!prop->value)
+ return ERR_PTR(-ENODATA);
+ if (len > prop->length)
+ return ERR_PTR(-EOVERFLOW);
+
+ return prop->value;
+}
+
+const void *of_get_property(const struct device_node *np, const char *name,
+ int *lenp)
+{
+ struct property *pp = of_find_property(np, name, lenp);
+
+ return pp ? pp->value : NULL;
+}
+
+bool of_device_is_available(const struct device_node *device)
+{
+ const char *status;
+ int statlen;
+
+ if (!device)
+ return false;
+
+ status = of_get_property(device, "status", &statlen);
+ if (status == NULL)
+ return true;
+
+ if (statlen > 0) {
+ if (!strcmp(status, "okay") || !strcmp(status, "ok"))
+ return true;
+ }
+
+ return false;
+}
+
+struct device_node *of_find_node_by_phandle(phandle handle)
+{
+ struct device_node *np;
+
+ if (!handle)
+ return NULL;
+
+ for_each_of_allnodes(np)
+ if (np->phandle == handle)
+ break;
+ of_node_get(np);
+ return np;
+}
+
+int of_read_u32(const struct device_node *np, const char *propname, u32 *outp)
+{
+ const __be32 *val;
+
+ debug("%s: %s: ", __func__, propname);
+ if (!np)
+ return -EINVAL;
+ val = of_find_property_value_of_size(np, propname, sizeof(*outp));
+ if (IS_ERR(val)) {
+ debug("(not found)\n");
+ return PTR_ERR(val);
+ }
+
+ *outp = be32_to_cpup(val);
+ debug("%#x (%d)\n", *outp, *outp);
+
+ return 0;
+}
+
+static int __of_parse_phandle_with_args(const struct device_node *np,
+ const char *list_name,
+ const char *cells_name,
+ int cell_count, int index,
+ struct of_phandle_args *out_args)
+{
+ const __be32 *list, *list_end;
+ int rc = 0, size, cur_index = 0;
+ uint32_t count = 0;
+ struct device_node *node = NULL;
+ phandle phandle;
+
+ /* Retrieve the phandle list property */
+ list = of_get_property(np, list_name, &size);
+ if (!list)
+ return -ENOENT;
+ list_end = list + size / sizeof(*list);
+
+ /* Loop over the phandles until all the requested entry is found */
+ while (list < list_end) {
+ rc = -EINVAL;
+ count = 0;
+
+ /*
+ * If phandle is 0, then it is an empty entry with no
+ * arguments. Skip forward to the next entry.
+ */
+ phandle = be32_to_cpup(list++);
+ if (phandle) {
+ /*
+ * Find the provider node and parse the #*-cells
+ * property to determine the argument length.
+ *
+ * This is not needed if the cell count is hard-coded
+ * (i.e. cells_name not set, but cell_count is set),
+ * except when we're going to return the found node
+ * below.
+ */
+ if (cells_name || cur_index == index) {
+ node = of_find_node_by_phandle(phandle);
+ if (!node) {
+ debug("%s: could not find phandle\n",
+ np->full_name);
+ goto err;
+ }
+ }
+
+ if (cells_name) {
+ if (of_read_u32(node, cells_name, &count)) {
+ debug("%s: could not get %s for %s\n",
+ np->full_name, cells_name,
+ node->full_name);
+ goto err;
+ }
+ } else {
+ count = cell_count;
+ }
+
+ /*
+ * Make sure that the arguments actually fit in the
+ * remaining property data length
+ */
+ if (list + count > list_end) {
+ debug("%s: arguments longer than property\n",
+ np->full_name);
+ goto err;
+ }
+ }
+
+ /*
+ * All of the error cases above bail out of the loop, so at
+ * this point, the parsing is successful. If the requested
+ * index matches, then fill the out_args structure and return,
+ * or return -ENOENT for an empty entry.
+ */
+ rc = -ENOENT;
+ if (cur_index == index) {
+ if (!phandle)
+ goto err;
+
+ if (out_args) {
+ int i;
+ if (WARN_ON(count > OF_MAX_PHANDLE_ARGS))
+ count = OF_MAX_PHANDLE_ARGS;
+ out_args->np = node;
+ out_args->args_count = count;
+ for (i = 0; i < count; i++)
+ out_args->args[i] =
+ be32_to_cpup(list++);
+ } else {
+ of_node_put(node);
+ }
+
+ /* Found it! return success */
+ return 0;
+ }
+
+ of_node_put(node);
+ node = NULL;
+ list += count;
+ cur_index++;
+ }
+
+ /*
+ * Unlock node before returning result; will be one of:
+ * -ENOENT : index is for empty phandle
+ * -EINVAL : parsing error on data
+ * [1..n] : Number of phandle (count mode; when index = -1)
+ */
+ rc = index < 0 ? cur_index : -ENOENT;
+ err:
+ if (node)
+ of_node_put(node);
+ return rc;
+}
+
+struct device_node *of_parse_phandle(const struct device_node *np,
+ const char *phandle_name, int index)
+{
+ struct of_phandle_args args;
+
+ if (index < 0)
+ return NULL;
+
+ if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
+ index, &args))
+ return NULL;
+
+ return args.np;
+}
+
+int of_parse_phandle_with_args(const struct device_node *np,
+ const char *list_name, const char *cells_name,
+ int index, struct of_phandle_args *out_args)
+{
+ if (index < 0)
+ return -EINVAL;
+ return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
+ index, out_args);
+}
+
+int of_read_u32_array(const struct device_node *np, const char *propname,
+ u32 *out_values, size_t sz)
+{
+ const __be32 *val;
+
+ debug("%s: %s: ", __func__, propname);
+ val = of_find_property_value_of_size(np, propname,
+ sz * sizeof(*out_values));
+
+ if (IS_ERR(val))
+ return PTR_ERR(val);
+
+ debug("size %zd\n", sz);
+ while (sz--)
+ *out_values++ = be32_to_cpup(val++);
+
+ return 0;
+}
--
2.11.0.483.g087da7b7c-goog
