blob: 8adffecd710b87f7d3237eb484c998aefdd71a84 [file] [log] [blame]
/*
* Procedures for creating, accessing and interpreting the device tree.
*
* Paul Mackerras August 1996.
* Copyright (C) 1996-2005 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
* {engebret|bergner}@us.ibm.com
*
* Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
*
* Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
* Grant Likely.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/console.h>
#include <linux/ctype.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/proc_fs.h>
#include "of_private.h"
LIST_HEAD(aliases_lookup);
struct device_node *of_root;
EXPORT_SYMBOL(of_root);
struct device_node *of_chosen;
struct device_node *of_aliases;
struct device_node *of_stdout;
static const char *of_stdout_options;
struct kset *of_kset;
/*
* Used to protect the of_aliases, to hold off addition of nodes to sysfs.
* This mutex must be held whenever modifications are being made to the
* device tree. The of_{attach,detach}_node() and
* of_{add,remove,update}_property() helpers make sure this happens.
*/
DEFINE_MUTEX(of_mutex);
/* use when traversing tree through the child, sibling,
* or parent members of struct device_node.
*/
DEFINE_RAW_SPINLOCK(devtree_lock);
int of_n_addr_cells(struct device_node *np)
{
const __be32 *ip;
do {
if (np->parent)
np = np->parent;
ip = of_get_property(np, "#address-cells", NULL);
if (ip)
return be32_to_cpup(ip);
} while (np->parent);
/* No #address-cells property for the root node */
return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
}
EXPORT_SYMBOL(of_n_addr_cells);
int of_n_size_cells(struct device_node *np)
{
const __be32 *ip;
do {
if (np->parent)
np = np->parent;
ip = of_get_property(np, "#size-cells", NULL);
if (ip)
return be32_to_cpup(ip);
} while (np->parent);
/* No #size-cells property for the root node */
return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
}
EXPORT_SYMBOL(of_n_size_cells);
#ifdef CONFIG_NUMA
int __weak of_node_to_nid(struct device_node *np)
{
return NUMA_NO_NODE;
}
#endif
#ifndef CONFIG_OF_DYNAMIC
static void of_node_release(struct kobject *kobj)
{
/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
}
#endif /* CONFIG_OF_DYNAMIC */
struct kobj_type of_node_ktype = {
.release = of_node_release,
};
static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t offset, size_t count)
{
struct property *pp = container_of(bin_attr, struct property, attr);
return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
}
/* always return newly allocated name, caller must free after use */
static const char *safe_name(struct kobject *kobj, const char *orig_name)
{
const char *name = orig_name;
struct kernfs_node *kn;
int i = 0;
/* don't be a hero. After 16 tries give up */
while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
sysfs_put(kn);
if (name != orig_name)
kfree(name);
name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
}
if (name == orig_name) {
name = kstrdup(orig_name, GFP_KERNEL);
} else {
pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
kobject_name(kobj), name);
}
return name;
}
int __of_add_property_sysfs(struct device_node *np, struct property *pp)
{
int rc;
/* Important: Don't leak passwords */
bool secure = strncmp(pp->name, "security-", 9) == 0;
if (!IS_ENABLED(CONFIG_SYSFS))
return 0;
if (!of_kset || !of_node_is_attached(np))
return 0;
sysfs_bin_attr_init(&pp->attr);
pp->attr.attr.name = safe_name(&np->kobj, pp->name);
pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
pp->attr.size = secure ? 0 : pp->length;
pp->attr.read = of_node_property_read;
rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
return rc;
}
int __of_attach_node_sysfs(struct device_node *np)
{
const char *name;
struct kobject *parent;
struct property *pp;
int rc;
if (!of_kset)
return 0;
np->kobj.kset = of_kset;
if (!np->parent) {
/* Nodes without parents are new top level trees */
name = safe_name(&of_kset->kobj, "base");
parent = NULL;
} else {
name = safe_name(&np->parent->kobj, kbasename(np->full_name));
parent = &np->parent->kobj;
}
if (!name)
return -ENOMEM;
rc = kobject_add(&np->kobj, parent, "%s", name);
kfree(name);
if (rc)
return rc;
for_each_property_of_node(np, pp)
__of_add_property_sysfs(np, pp);
return 0;
}
void __init of_core_init(void)
{
struct device_node *np;
/* Create the kset, and register existing nodes */
mutex_lock(&of_mutex);
of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
if (!of_kset) {
mutex_unlock(&of_mutex);
pr_err("devicetree: failed to register existing nodes\n");
return;
}
for_each_of_allnodes(np)
__of_attach_node_sysfs(np);
mutex_unlock(&of_mutex);
/* Symlink in /proc as required by userspace ABI */
if (of_root)
proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
}
static 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 (of_prop_cmp(pp->name, name) == 0) {
if (lenp)
*lenp = pp->length;
break;
}
}
return pp;
}
struct property *of_find_property(const struct device_node *np,
const char *name,
int *lenp)
{
struct property *pp;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
pp = __of_find_property(np, name, lenp);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return pp;
}
EXPORT_SYMBOL(of_find_property);
struct device_node *__of_find_all_nodes(struct device_node *prev)
{
struct device_node *np;
if (!prev) {
np = 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;
}
/**
* 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)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
np = __of_find_all_nodes(prev);
of_node_get(np);
of_node_put(prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_all_nodes);
/*
* 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)
{
struct property *pp = __of_find_property(np, name, lenp);
return pp ? pp->value : NULL;
}
/*
* 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)
{
struct property *pp = of_find_property(np, name, lenp);
return pp ? pp->value : NULL;
}
EXPORT_SYMBOL(of_get_property);
/*
* arch_match_cpu_phys_id - Match the given logical CPU and physical id
*
* @cpu: logical cpu index of a core/thread
* @phys_id: physical identifier of a core/thread
*
* CPU logical to physical index mapping is architecture specific.
* However this __weak function provides a default match of physical
* id to logical cpu index. phys_id provided here is usually values read
* from the device tree which must match the hardware internal registers.
*
* Returns true if the physical identifier and the logical cpu index
* correspond to the same core/thread, false otherwise.
*/
bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
{
return (u32)phys_id == cpu;
}
/**
* Checks if the given "prop_name" property holds the physical id of the
* core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
* NULL, local thread number within the core is returned in it.
*/
static bool __of_find_n_match_cpu_property(struct device_node *cpun,
const char *prop_name, int cpu, unsigned int *thread)
{
const __be32 *cell;
int ac, prop_len, tid;
u64 hwid;
ac = of_n_addr_cells(cpun);
cell = of_get_property(cpun, prop_name, &prop_len);
if (!cell || !ac)
return false;
prop_len /= sizeof(*cell) * ac;
for (tid = 0; tid < prop_len; tid++) {
hwid = of_read_number(cell, ac);
if (arch_match_cpu_phys_id(cpu, hwid)) {
if (thread)
*thread = tid;
return true;
}
cell += ac;
}
return false;
}
/*
* arch_find_n_match_cpu_physical_id - See if the given device node is
* for the cpu corresponding to logical cpu 'cpu'. Return true if so,
* else false. If 'thread' is non-NULL, the local thread number within the
* core is returned in it.
*/
bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
int cpu, unsigned int *thread)
{
/* Check for non-standard "ibm,ppc-interrupt-server#s" property
* for thread ids on PowerPC. If it doesn't exist fallback to
* standard "reg" property.
*/
if (IS_ENABLED(CONFIG_PPC) &&
__of_find_n_match_cpu_property(cpun,
"ibm,ppc-interrupt-server#s",
cpu, thread))
return true;
return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
}
/**
* of_get_cpu_node - Get device node associated with the given logical CPU
*
* @cpu: CPU number(logical index) for which device node is required
* @thread: if not NULL, local thread number within the physical core is
* returned
*
* The main purpose of this function is to retrieve the device node for the
* given logical CPU index. It should be used to initialize the of_node in
* cpu device. Once of_node in cpu device is populated, all the further
* references can use that instead.
*
* CPU logical to physical index mapping is architecture specific and is built
* before booting secondary cores. This function uses arch_match_cpu_phys_id
* which can be overridden by architecture specific implementation.
*
* Returns a node pointer for the logical cpu if found, else NULL.
*/
struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
{
struct device_node *cpun;
for_each_node_by_type(cpun, "cpu") {
if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
return cpun;
}
return NULL;
}
EXPORT_SYMBOL(of_get_cpu_node);
/**
* __of_device_is_compatible() - Check if the node matches given constraints
* @device: pointer to node
* @compat: required compatible string, NULL or "" for any match
* @type: required device_type value, NULL or "" for any match
* @name: required node name, NULL or "" for any match
*
* Checks if the given @compat, @type and @name strings match the
* properties of the given @device. A constraints can be skipped by
* passing NULL or an empty string as the constraint.
*
* Returns 0 for no match, and a positive integer on match. The return
* value is a relative score with larger values indicating better
* matches. The score is weighted for the most specific compatible value
* to get the highest score. Matching type is next, followed by matching
* name. Practically speaking, this results in the following priority
* order for matches:
*
* 1. specific compatible && type && name
* 2. specific compatible && type
* 3. specific compatible && name
* 4. specific compatible
* 5. general compatible && type && name
* 6. general compatible && type
* 7. general compatible && name
* 8. general compatible
* 9. type && name
* 10. type
* 11. name
*/
static int __of_device_is_compatible(const struct device_node *device,
const char *compat, const char *type, const char *name)
{
struct property *prop;
const char *cp;
int index = 0, score = 0;
/* Compatible match has highest priority */
if (compat && compat[0]) {
prop = __of_find_property(device, "compatible", NULL);
for (cp = of_prop_next_string(prop, NULL); cp;
cp = of_prop_next_string(prop, cp), index++) {
if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
score = INT_MAX/2 - (index << 2);
break;
}
}
if (!score)
return 0;
}
/* Matching type is better than matching name */
if (type && type[0]) {
if (!device->type || of_node_cmp(type, device->type))
return 0;
score += 2;
}
/* Matching name is a bit better than not */
if (name && name[0]) {
if (!device->name || of_node_cmp(name, device->name))
return 0;
score++;
}
return score;
}
/** Checks if the given "compat" string matches one of the strings in
* the device's "compatible" property
*/
int of_device_is_compatible(const struct device_node *device,
const char *compat)
{
unsigned long flags;
int res;
raw_spin_lock_irqsave(&devtree_lock, flags);
res = __of_device_is_compatible(device, compat, NULL, NULL);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return res;
}
EXPORT_SYMBOL(of_device_is_compatible);
/**
* of_machine_is_compatible - Test root of device tree for a given compatible value
* @compat: compatible string to look for in root node's compatible property.
*
* Returns a positive integer if the root node has the given value in its
* compatible property.
*/
int of_machine_is_compatible(const char *compat)
{
struct device_node *root;
int rc = 0;
root = of_find_node_by_path("/");
if (root) {
rc = of_device_is_compatible(root, compat);
of_node_put(root);
}
return rc;
}
EXPORT_SYMBOL(of_machine_is_compatible);
/**
* __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
*/
static 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;
}
/**
* of_device_is_available - check if a device is available for use
*
* @device: Node to check for availability
*
* 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)
{
unsigned long flags;
bool res;
raw_spin_lock_irqsave(&devtree_lock, flags);
res = __of_device_is_available(device);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return res;
}
EXPORT_SYMBOL(of_device_is_available);
/**
* of_device_is_big_endian - check if a device has BE registers
*
* @device: Node to check for endianness
*
* Returns true if the device has a "big-endian" property, or if the kernel
* was compiled for BE *and* the device has a "native-endian" property.
* Returns false otherwise.
*
* Callers would nominally use ioread32be/iowrite32be if
* of_device_is_big_endian() == true, or readl/writel otherwise.
*/
bool of_device_is_big_endian(const struct device_node *device)
{
if (of_property_read_bool(device, "big-endian"))
return true;
if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
of_property_read_bool(device, "native-endian"))
return true;
return false;
}
EXPORT_SYMBOL(of_device_is_big_endian);
/**
* of_get_parent - Get a node's parent if any
* @node: Node to get parent
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_get_parent(const struct device_node *node)
{
struct device_node *np;
unsigned long flags;
if (!node)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
np = of_node_get(node->parent);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_get_parent);
/**
* of_get_next_parent - Iterate to a node's parent
* @node: Node to get parent of
*
* This is like of_get_parent() except that it drops the
* refcount on the passed node, making it suitable for iterating
* through a node's parents.
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_get_next_parent(struct device_node *node)
{
struct device_node *parent;
unsigned long flags;
if (!node)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
parent = of_node_get(node->parent);
of_node_put(node);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return parent;
}
EXPORT_SYMBOL(of_get_next_parent);
static struct device_node *__of_get_next_child(const struct device_node *node,
struct device_node *prev)
{
struct device_node *next;
if (!node)
return NULL;
next = prev ? prev->sibling : node->child;
for (; next; next = next->sibling)
if (of_node_get(next))
break;
of_node_put(prev);
return next;
}
#define __for_each_child_of_node(parent, child) \
for (child = __of_get_next_child(parent, NULL); child != NULL; \
child = __of_get_next_child(parent, child))
/**
* of_get_next_child - Iterate a node childs
* @node: parent node
* @prev: previous child of the parent node, or NULL to get first
*
* Returns a node pointer with refcount incremented, use of_node_put() on
* it when done. Returns NULL when prev is the last child. Decrements the
* refcount of prev.
*/
struct device_node *of_get_next_child(const struct device_node *node,
struct device_node *prev)
{
struct device_node *next;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
next = __of_get_next_child(node, prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
EXPORT_SYMBOL(of_get_next_child);
/**
* of_get_next_available_child - Find the next available child node
* @node: parent node
* @prev: previous child of the parent node, or NULL to get first
*
* This function is like of_get_next_child(), except that it
* automatically skips any disabled nodes (i.e. status = "disabled").
*/
struct device_node *of_get_next_available_child(const struct device_node *node,
struct device_node *prev)
{
struct device_node *next;
unsigned long flags;
if (!node)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
next = prev ? prev->sibling : node->child;
for (; next; next = next->sibling) {
if (!__of_device_is_available(next))
continue;
if (of_node_get(next))
break;
}
of_node_put(prev);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return next;
}
EXPORT_SYMBOL(of_get_next_available_child);
/**
* of_get_compatible_child - Find compatible child node
* @parent: parent node
* @compatible: compatible string
*
* Lookup child node whose compatible property contains the given compatible
* string.
*
* Returns a node pointer with refcount incremented, use of_node_put() on it
* when done; or NULL if not found.
*/
struct device_node *of_get_compatible_child(const struct device_node *parent,
const char *compatible)
{
struct device_node *child;
for_each_child_of_node(parent, child) {
if (of_device_is_compatible(child, compatible))
break;
}
return child;
}
EXPORT_SYMBOL(of_get_compatible_child);
/**
* of_get_child_by_name - Find the child node by name for a given parent
* @node: parent node
* @name: child name to look for.
*
* This function looks for child node for given matching name
*
* Returns a node pointer if found, with refcount incremented, use
* of_node_put() on it when done.
* Returns NULL if node is not found.
*/
struct device_node *of_get_child_by_name(const struct device_node *node,
const char *name)
{
struct device_node *child;
for_each_child_of_node(node, child)
if (child->name && (of_node_cmp(child->name, name) == 0))
break;
return child;
}
EXPORT_SYMBOL(of_get_child_by_name);
static struct device_node *__of_find_node_by_path(struct device_node *parent,
const char *path)
{
struct device_node *child;
int len;
len = strcspn(path, "/:");
if (!len)
return NULL;
__for_each_child_of_node(parent, child) {
const char *name = strrchr(child->full_name, '/');
if (WARN(!name, "malformed device_node %s\n", child->full_name))
continue;
name++;
if (strncmp(path, name, len) == 0 && (strlen(name) == len))
return child;
}
return NULL;
}
/**
* of_find_node_opts_by_path - Find a node matching a full OF path
* @path: Either the full path to match, or if the path does not
* start with '/', the name of a property of the /aliases
* node (an alias). In the case of an alias, the node
* matching the alias' value will be returned.
* @opts: Address of a pointer into which to store the start of
* an options string appended to the end of the path with
* a ':' separator.
*
* Valid paths:
* /foo/bar Full path
* foo Valid alias
* foo/bar Valid alias + relative path
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
{
struct device_node *np = NULL;
struct property *pp;
unsigned long flags;
const char *separator = strchr(path, ':');
if (opts)
*opts = separator ? separator + 1 : NULL;
if (strcmp(path, "/") == 0)
return of_node_get(of_root);
/* The path could begin with an alias */
if (*path != '/') {
int len;
const char *p = separator;
if (!p)
p = strchrnul(path, '/');
len = p - path;
/* of_aliases must not be NULL */
if (!of_aliases)
return NULL;
for_each_property_of_node(of_aliases, pp) {
if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
np = of_find_node_by_path(pp->value);
break;
}
}
if (!np)
return NULL;
path = p;
}
/* Step down the tree matching path components */
raw_spin_lock_irqsave(&devtree_lock, flags);
if (!np)
np = of_node_get(of_root);
while (np && *path == '/') {
path++; /* Increment past '/' delimiter */
np = __of_find_node_by_path(np, path);
path = strchrnul(path, '/');
if (separator && separator < path)
break;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_opts_by_path);
/**
* of_find_node_by_name - Find a node by its "name" property
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @name: The name string to match against
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_by_name(struct device_node *from,
const char *name)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np)
if (np->name && (of_node_cmp(np->name, name) == 0)
&& of_node_get(np))
break;
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_name);
/**
* of_find_node_by_type - Find a node by its "device_type" property
* @from: The node to start searching from, or NULL to start searching
* the entire device tree. The node you pass will not be
* searched, only the next one will; typically, you pass
* what the previous call returned. of_node_put() will be
* called on from for you.
* @type: The type string to match against
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_by_type(struct device_node *from,
const char *type)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np)
if (np->type && (of_node_cmp(np->type, type) == 0)
&& of_node_get(np))
break;
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_type);
/**
* of_find_compatible_node - Find a node based on type and one of the
* tokens in its "compatible" property
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @type: The type string to match "device_type" or NULL to ignore
* @compatible: The string to match to one of the tokens in the device
* "compatible" list.
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_compatible_node(struct device_node *from,
const char *type, const char *compatible)
{
struct device_node *np;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np)
if (__of_device_is_compatible(np, compatible, type, NULL) &&
of_node_get(np))
break;
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_compatible_node);
/**
* of_find_node_with_property - Find a node which has a property with
* the given name.
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @prop_name: The name of the property to look for.
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_with_property(struct device_node *from,
const char *prop_name)
{
struct device_node *np;
struct property *pp;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np) {
for (pp = np->properties; pp; pp = pp->next) {
if (of_prop_cmp(pp->name, prop_name) == 0) {
of_node_get(np);
goto out;
}
}
}
out:
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_with_property);
static
const struct of_device_id *__of_match_node(const struct of_device_id *matches,
const struct device_node *node)
{
const struct of_device_id *best_match = NULL;
int score, best_score = 0;
if (!matches)
return NULL;
for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
score = __of_device_is_compatible(node, matches->compatible,
matches->type, matches->name);
if (score > best_score) {
best_match = matches;
best_score = score;
}
}
return best_match;
}
/**
* of_match_node - Tell if a device_node has a matching of_match structure
* @matches: array of of device match structures to search in
* @node: the of device structure to match against
*
* Low level utility function used by device matching.
*/
const struct of_device_id *of_match_node(const struct of_device_id *matches,
const struct device_node *node)
{
const struct of_device_id *match;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
match = __of_match_node(matches, node);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return match;
}
EXPORT_SYMBOL(of_match_node);
/**
* of_find_matching_node_and_match - Find a node based on an of_device_id
* match table.
* @from: The node to start searching from or NULL, the node
* you pass will not be searched, only the next one
* will; typically, you pass what the previous call
* returned. of_node_put() will be called on it
* @matches: array of of device match structures to search in
* @match Updated to point at the matches entry which matched
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_matching_node_and_match(struct device_node *from,
const struct of_device_id *matches,
const struct of_device_id **match)
{
struct device_node *np;
const struct of_device_id *m;
unsigned long flags;
if (match)
*match = NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes_from(from, np) {
m = __of_match_node(matches, np);
if (m && of_node_get(np)) {
if (match)
*match = m;
break;
}
}
of_node_put(from);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_matching_node_and_match);
/**
* of_modalias_node - Lookup appropriate modalias for a device node
* @node: pointer to a device tree node
* @modalias: Pointer to buffer that modalias value will be copied into
* @len: Length of modalias value
*
* Based on the value of the compatible property, this routine will attempt
* to choose an appropriate modalias value for a particular device tree node.
* It does this by stripping the manufacturer prefix (as delimited by a ',')
* from the first entry in the compatible list property.
*
* This routine returns 0 on success, <0 on failure.
*/
int of_modalias_node(struct device_node *node, char *modalias, int len)
{
const char *compatible, *p;
int cplen;
compatible = of_get_property(node, "compatible", &cplen);
if (!compatible || strlen(compatible) > cplen)
return -ENODEV;
p = strchr(compatible, ',');
strlcpy(modalias, p ? p + 1 : compatible, len);
return 0;
}
EXPORT_SYMBOL_GPL(of_modalias_node);
/**
* 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)
{
struct device_node *np;
unsigned long flags;
if (!handle)
return NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
for_each_of_allnodes(np)
if (np->phandle == handle)
break;
of_node_get(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_by_phandle);
/**
* of_property_count_elems_of_size - Count the number of elements in a property
*
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @elem_size: size of the individual element
*
* Search for a property in a device node and count the number of elements of
* size elem_size in it. Returns number of elements on sucess, -EINVAL if the
* property does not exist or its length does not match a multiple of elem_size
* and -ENODATA if the property does not have a value.
*/
int of_property_count_elems_of_size(const struct device_node *np,
const char *propname, int elem_size)
{
struct property *prop = of_find_property(np, propname, NULL);
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
if (prop->length % elem_size != 0) {
pr_err("size of %s in node %s is not a multiple of %d\n",
propname, np->full_name, elem_size);
return -EINVAL;
}
return prop->length / elem_size;
}
EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
/**
* of_find_property_value_of_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
*
* Search for a property in a device node and valid the requested size.
* 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;
}
/**
* of_property_read_u32_index - Find and read a u32 from a multi-value property.
*
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @index: index of the u32 in the list of values
* @out_value: pointer to return value, modified only if no error.
*
* Search for a property in a device node and read nth 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 u32 value can be decoded.
*/
int of_property_read_u32_index(const struct device_node *np,
const char *propname,
u32 index, u32 *out_value)
{
const u32 *val = of_find_property_value_of_size(np, propname,
((index + 1) * sizeof(*out_value)));
if (IS_ERR(val))
return PTR_ERR(val);
*out_value = be32_to_cpup(((__be32 *)val) + index);
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u32_index);
/**
* of_property_read_u8_array - Find and read an array of u8 from a property.
*
* @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
*
* Search for a property in a device node and read 8-bit value(s) 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.
*
* dts entry of array should be like:
* property = /bits/ 8 <0x50 0x60 0x70>;
*
* The out_values is modified only if a valid u8 value can be decoded.
*/
int of_property_read_u8_array(const struct device_node *np,
const char *propname, u8 *out_values, size_t sz)
{
const u8 *val = of_find_property_value_of_size(np, propname,
(sz * sizeof(*out_values)));
if (IS_ERR(val))
return PTR_ERR(val);
while (sz--)
*out_values++ = *val++;
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u8_array);
/**
* of_property_read_u16_array - Find and read an array of u16 from a property.
*
* @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
*
* Search for a property in a device node and read 16-bit value(s) 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.
*
* dts entry of array should be like:
* property = /bits/ 16 <0x5000 0x6000 0x7000>;
*
* The out_values is modified only if a valid u16 value can be decoded.
*/
int of_property_read_u16_array(const struct device_node *np,
const char *propname, u16 *out_values, size_t sz)
{
const __be16 *val = of_find_property_value_of_size(np, propname,
(sz * sizeof(*out_values)));
if (IS_ERR(val))
return PTR_ERR(val);
while (sz--)
*out_values++ = be16_to_cpup(val++);
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u16_array);
/**
* of_property_read_u32_array - Find and read an array of 32 bit integers
* from a property.
*
* @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
*
* Search for a property in a device node and read 32-bit value(s) 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_values is modified only if a valid u32 value can be decoded.
*/
int of_property_read_u32_array(const struct device_node *np,
const char *propname, u32 *out_values,
size_t sz)
{
const __be32 *val = of_find_property_value_of_size(np, propname,
(sz * sizeof(*out_values)));
if (IS_ERR(val))
return PTR_ERR(val);
while (sz--)
*out_values++ = be32_to_cpup(val++);
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u32_array);
/**
* of_property_read_u64 - Find and read a 64 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.
* @out_value: pointer to return value, modified only if return value is 0.
*
* Search for a property in a device node and read a 64-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_property_read_u64(const struct device_node *np, const char *propname,
u64 *out_value)
{
const __be32 *val = of_find_property_value_of_size(np, propname,
sizeof(*out_value));
if (IS_ERR(val))
return PTR_ERR(val);
*out_value = of_read_number(val, 2);
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u64);
/**
* of_property_read_u64_array - Find and read an array of 64 bit integers
* from a property.
*
* @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
*
* Search for a property in a device node and read 64-bit value(s) 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_values is modified only if a valid u64 value can be decoded.
*/
int of_property_read_u64_array(const struct device_node *np,
const char *propname, u64 *out_values,
size_t sz)
{
const __be32 *val = of_find_property_value_of_size(np, propname,
(sz * sizeof(*out_values)));
if (IS_ERR(val))
return PTR_ERR(val);
while (sz--) {
*out_values++ = of_read_number(val, 2);
val += 2;
}
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u64_array);
/**
* of_property_read_string - Find and read a string from a property
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @out_string: pointer to null terminated return string, modified only if
* return value is 0.
*
* Search for a property in a device tree node and retrieve a null
* terminated string value (pointer to data, not a copy). Returns 0 on
* success, -EINVAL if the property does not exist, -ENODATA if property
* does not have a value, and -EILSEQ if the string is not null-terminated
* within the length of the property data.
*
* The out_string pointer is modified only if a valid string can be decoded.
*/
int of_property_read_string(struct device_node *np, const char *propname,
const char **out_string)
{
struct property *prop = of_find_property(np, propname, NULL);
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
if (strnlen(prop->value, prop->length) >= prop->length)
return -EILSEQ;
*out_string = prop->value;
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_string);
/**
* of_property_match_string() - Find string in a list and return index
* @np: pointer to node containing string list property
* @propname: string list property name
* @string: pointer to string to search for in string list
*
* This function searches a string list property and returns the index
* of a specific string value.
*/
int of_property_match_string(struct device_node *np, const char *propname,
const char *string)
{
struct property *prop = of_find_property(np, propname, NULL);
size_t l;
int i;
const char *p, *end;
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
p = prop->value;
end = p + prop->length;
for (i = 0; p < end; i++, p += l) {
l = strnlen(p, end - p) + 1;
if (p + l > end)
return -EILSEQ;
pr_debug("comparing %s with %s\n", string, p);
if (strcmp(string, p) == 0)
return i; /* Found it; return index */
}
return -ENODATA;
}
EXPORT_SYMBOL_GPL(of_property_match_string);
/**
* of_property_read_string_helper() - Utility helper for parsing string properties
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @out_strs: output array of string pointers.
* @sz: number of array elements to read.
* @skip: Number of strings to skip over at beginning of list.
*
* Don't call this function directly. It is a utility helper for the
* of_property_read_string*() family of functions.
*/
int of_property_read_string_helper(struct device_node *np, const char *propname,
const char **out_strs, size_t sz, int skip)
{
struct property *prop = of_find_property(np, propname, NULL);
int l = 0, i = 0;
const char *p, *end;
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
p = prop->value;
end = p + prop->length;
for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
l = strnlen(p, end - p) + 1;
if (p + l > end)
return -EILSEQ;
if (out_strs && i >= skip)
*out_strs++ = p;
}
i -= skip;
return i <= 0 ? -ENODATA : i;
}
EXPORT_SYMBOL_GPL(of_property_read_string_helper);
void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
{
int i;
printk("%s %s", msg, of_node_full_name(args->np));
for (i = 0; i < args->args_count; i++)
printk(i ? ",%08x" : ":%08x", args->args[i]);
printk("\n");
}
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) {
pr_err("%s: could not find phandle\n",
np->full_name);
goto err;
}
}
if (cells_name) {
if (of_property_read_u32(node, cells_name,
&count)) {
pr_err("%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) {
pr_err("%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 > MAX_PHANDLE_ARGS))
count = 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;
}
/**
* 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)
{
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;
}
EXPORT_SYMBOL(of_parse_phandle);
/**
* 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)
{
if (index < 0)
return -EINVAL;
return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
index, out_args);
}
EXPORT_SYMBOL(of_parse_phandle_with_args);
/**
* of_parse_phandle_with_fixed_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
* @cell_count: number of argument cells following the phandle
* @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 {
* }
*
* phandle2: node2 {
* }
*
* node3 {
* list = <&phandle1 0 2 &phandle2 2 3>;
* }
*
* To get a device_node of the `node2' node you may call this:
* of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
*/
int of_parse_phandle_with_fixed_args(const struct device_node *np,
const char *list_name, int cell_count,
int index, struct of_phandle_args *out_args)
{
if (index < 0)
return -EINVAL;
return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
index, out_args);
}
EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
/**
* of_count_phandle_with_args() - Find the number of phandles references in a property
* @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
*
* Returns the number of phandle + argument tuples within a property. It
* is a typical pattern to encode a list of phandle and variable
* arguments into a single property. The number of arguments is encoded
* by a property in the phandle-target node. For example, a gpios
* property would contain a list of GPIO specifies consisting of a
* phandle and 1 or more arguments. The number of arguments are
* determined by the #gpio-cells property in the node pointed to by the
* phandle.
*/
int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
const char *cells_name)
{
return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
NULL);
}
EXPORT_SYMBOL(of_count_phandle_with_args);
/**
* __of_add_property - Add a property to a node without lock operations
*/
int __of_add_property(struct device_node *np, struct property *prop)
{
struct property **next;
prop->next = NULL;
next = &np->properties;
while (*next) {
if (strcmp(prop->name, (*next)->name) == 0)
/* duplicate ! don't insert it */
return -EEXIST;
next = &(*next)->next;
}
*next = prop;
return 0;
}
/**
* of_add_property - Add a property to a node
*/
int of_add_property(struct device_node *np, struct property *prop)
{
unsigned long flags;
int rc;
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_add_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!rc)
__of_add_property_sysfs(np, prop);
mutex_unlock(&of_mutex);
if (!rc)
of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
return rc;
}
int __of_remove_property(struct device_node *np, struct property *prop)
{
struct property **next;
for (next = &np->properties; *next; next = &(*next)->next) {
if (*next == prop)
break;
}
if (*next == NULL)
return -ENODEV;
/* found the node */
*next = prop->next;
prop->next = np->deadprops;
np->deadprops = prop;
return 0;
}
void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
{
sysfs_remove_bin_file(&np->kobj, &prop->attr);
kfree(prop->attr.attr.name);
}
void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
{
if (!IS_ENABLED(CONFIG_SYSFS))
return;
/* at early boot, bail here and defer setup to of_init() */
if (of_kset && of_node_is_attached(np))
__of_sysfs_remove_bin_file(np, prop);
}
/**
* of_remove_property - Remove a property from a node.
*
* Note that we don't actually remove it, since we have given out
* who-knows-how-many pointers to the data using get-property.
* Instead we just move the property to the "dead properties"
* list, so it won't be found any more.
*/
int of_remove_property(struct device_node *np, struct property *prop)
{
unsigned long flags;
int rc;
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_remove_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!rc)
__of_remove_property_sysfs(np, prop);
mutex_unlock(&of_mutex);
if (!rc)
of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
return rc;
}
int __of_update_property(struct device_node *np, struct property *newprop,
struct property **oldpropp)
{
struct property **next, *oldprop;
for (next = &np->properties; *next; next = &(*next)->next) {
if (of_prop_cmp((*next)->name, newprop->name) == 0)
break;
}
*oldpropp = oldprop = *next;
if (oldprop) {
/* replace the node */
newprop->next = oldprop->next;
*next = newprop;
oldprop->next = np->deadprops;
np->deadprops = oldprop;
} else {
/* new node */
newprop->next = NULL;
*next = newprop;
}
return 0;
}
void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
struct property *oldprop)
{
if (!IS_ENABLED(CONFIG_SYSFS))
return;
/* At early boot, bail out and defer setup to of_init() */
if (!of_kset)
return;
if (oldprop)
__of_sysfs_remove_bin_file(np, oldprop);
__of_add_property_sysfs(np, newprop);
}
/*
* of_update_property - Update a property in a node, if the property does
* not exist, add it.
*
* Note that we don't actually remove it, since we have given out
* who-knows-how-many pointers to the data using get-property.
* Instead we just move the property to the "dead properties" list,
* and add the new property to the property list
*/
int of_update_property(struct device_node *np, struct property *newprop)
{
struct property *oldprop;
unsigned long flags;
int rc;
if (!newprop->name)
return -EINVAL;
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_update_property(np, newprop, &oldprop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!rc)
__of_update_property_sysfs(np, newprop, oldprop);
mutex_unlock(&of_mutex);
if (!rc)
of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
return rc;
}
static void of_alias_add(struct alias_prop *ap, struct device_node *np,
int id, const char *stem, int stem_len)
{
ap->np = np;
ap->id = id;
strncpy(ap->stem, stem, stem_len);
ap->stem[stem_len] = 0;
list_add_tail(&ap->link, &aliases_lookup);
pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
ap->alias, ap->stem, ap->id, of_node_full_name(np));
}
/**
* of_alias_scan - Scan all properties of the 'aliases' node
*
* The function scans all the properties of the 'aliases' node and populates
* the global lookup table with the properties. It returns the
* number of alias properties found, or an error code in case of failure.
*
* @dt_alloc: An allocator that provides a virtual address to memory
* for storing the resulting tree
*/
void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
{
struct property *pp;
of_aliases = of_find_node_by_path("/aliases");
of_chosen = of_find_node_by_path("/chosen");
if (of_chosen == NULL)
of_chosen = of_find_node_by_path("/chosen@0");
if (of_chosen) {
/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
const char *name = of_get_property(of_chosen, "stdout-path", NULL);
if (!name)
name = of_get_property(of_chosen, "linux,stdout-path", NULL);
if (IS_ENABLED(CONFIG_PPC) && !name)
name = of_get_property(of_aliases, "stdout", NULL);
if (name)
of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
}
if (!of_aliases)
return;
for_each_property_of_node(of_aliases, pp) {
const char *start = pp->name;
const char *end = start + strlen(start);
struct device_node *np;
struct alias_prop *ap;
int id, len;
/* Skip those we do not want to proceed */
if (!strcmp(pp->name, "name") ||
!strcmp(pp->name, "phandle") ||
!strcmp(pp->name, "linux,phandle"))
continue;
np = of_find_node_by_path(pp->value);
if (!np)
continue;
/* walk the alias backwards to extract the id and work out
* the 'stem' string */
while (isdigit(*(end-1)) && end > start)
end--;
len = end - start;
if (kstrtoint(end, 10, &id) < 0)
continue;
/* Allocate an alias_prop with enough space for the stem */
ap = dt_alloc(sizeof(*ap) + len + 1, 4);
if (!ap)
continue;
memset(ap, 0, sizeof(*ap) + len + 1);
ap->alias = start;
of_alias_add(ap, np, id, start, len);
}
}
/**
* of_alias_get_id - Get alias id for the given device_node
* @np: Pointer to the given device_node
* @stem: Alias stem of the given device_node
*
* The function travels the lookup table to get the alias id for the given
* device_node and alias stem. It returns the alias id if found.
*/
int of_alias_get_id(struct device_node *np, const char *stem)
{
struct alias_prop *app;
int id = -ENODEV;
mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (strcmp(app->stem, stem) != 0)
continue;
if (np == app->np) {
id = app->id;
break;
}
}
mutex_unlock(&of_mutex);
return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_id);
/**
* of_alias_get_highest_id - Get highest alias id for the given stem
* @stem: Alias stem to be examined
*
* The function travels the lookup table to get the highest alias id for the
* given alias stem. It returns the alias id if found.
*/
int of_alias_get_highest_id(const char *stem)
{
struct alias_prop *app;
int id = -ENODEV;
mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (strcmp(app->stem, stem) != 0)
continue;
if (app->id > id)
id = app->id;
}
mutex_unlock(&of_mutex);
return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
u32 *pu)
{
const void *curv = cur;
if (!prop)
return NULL;
if (!cur) {
curv = prop->value;
goto out_val;
}
curv += sizeof(*cur);
if (curv >= prop->value + prop->length)
return NULL;
out_val:
*pu = be32_to_cpup(curv);
return curv;
}
EXPORT_SYMBOL_GPL(of_prop_next_u32);
const char *of_prop_next_string(struct property *prop, const char *cur)
{
const void *curv = cur;
if (!prop)
return NULL;
if (!cur)
return prop->value;
curv += strlen(cur) + 1;
if (curv >= prop->value + prop->length)
return NULL;
return curv;
}
EXPORT_SYMBOL_GPL(of_prop_next_string);
/**
* of_console_check() - Test and setup console for DT setup
* @dn - Pointer to device node
* @name - Name to use for preferred console without index. ex. "ttyS"
* @index - Index to use for preferred console.
*
* Check if the given device node matches the stdout-path property in the
* /chosen node. If it does then register it as the preferred console and return
* TRUE. Otherwise return FALSE.
*/
bool of_console_check(struct device_node *dn, char *name, int index)
{
if (!dn || dn != of_stdout || console_set_on_cmdline)
return false;
return !add_preferred_console(name, index,
kstrdup(of_stdout_options, GFP_KERNEL));
}
EXPORT_SYMBOL_GPL(of_console_check);
/**
* of_find_next_cache_node - Find a node's subsidiary cache
* @np: node of type "cpu" or "cache"
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done. Caller should hold a reference
* to np.
*/
struct device_node *of_find_next_cache_node(const struct device_node *np)
{
struct device_node *child;
const phandle *handle;
handle = of_get_property(np, "l2-cache", NULL);
if (!handle)
handle = of_get_property(np, "next-level-cache", NULL);
if (handle)
return of_find_node_by_phandle(be32_to_cpup(handle));
/* OF on pmac has nodes instead of properties named "l2-cache"
* beneath CPU nodes.
*/
if (IS_ENABLED(CONFIG_PPC_PMAC) && !strcmp(np->type, "cpu"))
for_each_child_of_node(np, child)
if (!strcmp(child->type, "cache"))
return child;
return NULL;
}
/**
* of_graph_parse_endpoint() - parse common endpoint node properties
* @node: pointer to endpoint device_node
* @endpoint: pointer to the OF endpoint data structure
*
* The caller should hold a reference to @node.
*/
int of_graph_parse_endpoint(const struct device_node *node,
struct of_endpoint *endpoint)
{
struct device_node *port_node = of_get_parent(node);
WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
__func__, node->full_name);
memset(endpoint, 0, sizeof(*endpoint));
endpoint->local_node = node;
/*
* It doesn't matter whether the two calls below succeed.
* If they don't then the default value 0 is used.
*/
of_property_read_u32(port_node, "reg", &endpoint->port);
of_property_read_u32(node, "reg", &endpoint->id);
of_node_put(port_node);
return 0;
}
EXPORT_SYMBOL(of_graph_parse_endpoint);
/**
* of_graph_get_port_by_id() - get the port matching a given id
* @parent: pointer to the parent device node
* @id: id of the port
*
* Return: A 'port' node pointer with refcount incremented. The caller
* has to use of_node_put() on it when done.
*/
struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
{
struct device_node *node, *port;
node = of_get_child_by_name(parent, "ports");
if (node)
parent = node;
for_each_child_of_node(parent, port) {
u32 port_id = 0;
if (of_node_cmp(port->name, "port") != 0)
continue;
of_property_read_u32(port, "reg", &port_id);
if (id == port_id)
break;
}
of_node_put(node);
return port;
}
EXPORT_SYMBOL(of_graph_get_port_by_id);
/**
* of_graph_get_next_endpoint() - get next endpoint node
* @parent: pointer to the parent device node
* @prev: previous endpoint node, or NULL to get first
*
* Return: An 'endpoint' node pointer with refcount incremented. Refcount
* of the passed @prev node is decremented.
*/
struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
struct device_node *prev)
{
struct device_node *endpoint;
struct device_node *port;
if (!parent)
return NULL;
/*
* Start by locating the port node. If no previous endpoint is specified
* search for the first port node, otherwise get the previous endpoint
* parent port node.
*/
if (!prev) {
struct device_node *node;
node = of_get_child_by_name(parent, "ports");
if (node)
parent = node;
port = of_get_child_by_name(parent, "port");
of_node_put(node);
if (!port) {
pr_err("%s(): no port node found in %s\n",
__func__, parent->full_name);
return NULL;
}
} else {
port = of_get_parent(prev);
if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
__func__, prev->full_name))
return NULL;
}
while (1) {
/*
* Now that we have a port node, get the next endpoint by
* getting the next child. If the previous endpoint is NULL this
* will return the first child.
*/
endpoint = of_get_next_child(port, prev);
if (endpoint) {
of_node_put(port);
return endpoint;
}
/* No more endpoints under this port, try the next one. */
prev = NULL;
do {
port = of_get_next_child(parent, port);
if (!port)
return NULL;
} while (of_node_cmp(port->name, "port"));
}
}
EXPORT_SYMBOL(of_graph_get_next_endpoint);
/**
* of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
* @parent: pointer to the parent device node
* @port_reg: identifier (value of reg property) of the parent port node
* @reg: identifier (value of reg property) of the endpoint node
*
* Return: An 'endpoint' node pointer which is identified by reg and at the same
* is the child of a port node identified by port_reg. reg and port_reg are
* ignored when they are -1.
*/
struct device_node *of_graph_get_endpoint_by_regs(
const struct device_node *parent, int port_reg, int reg)
{
struct of_endpoint endpoint;
struct device_node *node = NULL;
for_each_endpoint_of_node(parent, node) {
of_graph_parse_endpoint(node, &endpoint);
if (((port_reg == -1) || (endpoint.port == port_reg)) &&
((reg == -1) || (endpoint.id == reg)))
return node;
}
return NULL;
}
EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
/**
* of_graph_get_remote_port_parent() - get remote port's parent node
* @node: pointer to a local endpoint device_node
*
* Return: Remote device node associated with remote endpoint node linked
* to @node. Use of_node_put() on it when done.
*/
struct device_node *of_graph_get_remote_port_parent(
const struct device_node *node)
{
struct device_node *np;
unsigned int depth;
/* Get remote endpoint node. */
np = of_parse_phandle(node, "remote-endpoint", 0);
/* Walk 3 levels up only if there is 'ports' node. */
for (depth = 3; depth && np; depth--) {
np = of_get_next_parent(np);
if (depth == 2 && of_node_cmp(np->name, "ports"))
break;
}
return np;
}
EXPORT_SYMBOL(of_graph_get_remote_port_parent);
/**
* of_graph_get_remote_port() - get remote port node
* @node: pointer to a local endpoint device_node
*
* Return: Remote port node associated with remote endpoint node linked
* to @node. Use of_node_put() on it when done.
*/
struct device_node *of_graph_get_remote_port(const struct device_node *node)
{
struct device_node *np;
/* Get remote endpoint node. */
np = of_parse_phandle(node, "remote-endpoint", 0);
if (!np)
return NULL;
return of_get_next_parent(np);
}
EXPORT_SYMBOL(of_graph_get_remote_port);