linux/drivers/of/base.c

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/*
* 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/ctype.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/spinlock.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include "of_private.h"
LIST_HEAD(aliases_lookup);
struct device_node *of_allnodes;
EXPORT_SYMBOL(of_allnodes);
struct device_node *of_chosen;
struct device_node *of_aliases;
static struct device_node *of_stdout;
DEFINE_MUTEX(of_aliases_mutex);
/* use when traversing tree through the allnext, 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);
#if defined(CONFIG_OF_DYNAMIC)
/**
* of_node_get - Increment refcount of a node
* @node: Node to inc refcount, NULL is supported to
* simplify writing of callers
*
* Returns node.
*/
struct device_node *of_node_get(struct device_node *node)
{
if (node)
kref_get(&node->kref);
return node;
}
EXPORT_SYMBOL(of_node_get);
static inline struct device_node *kref_to_device_node(struct kref *kref)
{
return container_of(kref, struct device_node, kref);
}
/**
* of_node_release - release a dynamically allocated node
* @kref: kref element of the node to be released
*
* In of_node_put() this function is passed to kref_put()
* as the destructor.
*/
static void of_node_release(struct kref *kref)
{
struct device_node *node = kref_to_device_node(kref);
struct property *prop = node->properties;
/* We should never be releasing nodes that haven't been detached. */
if (!of_node_check_flag(node, OF_DETACHED)) {
pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
dump_stack();
kref_init(&node->kref);
return;
}
if (!of_node_check_flag(node, OF_DYNAMIC))
return;
while (prop) {
struct property *next = prop->next;
kfree(prop->name);
kfree(prop->value);
kfree(prop);
prop = next;
if (!prop) {
prop = node->deadprops;
node->deadprops = NULL;
}
}
kfree(node->full_name);
kfree(node->data);
kfree(node);
}
/**
* of_node_put - Decrement refcount of a node
* @node: Node to dec refcount, NULL is supported to
* simplify writing of callers
*
*/
void of_node_put(struct device_node *node)
{
if (node)
kref_put(&node->kref, of_node_release);
}
EXPORT_SYMBOL(of_node_put);
#endif /* CONFIG_OF_DYNAMIC */
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);
/**
* 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 = prev ? prev->allnext : of_allnodes;
for (; np != NULL; np = np->allnext)
if (of_node_get(np))
break;
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.
*/
static 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)
return false;
prop_len /= sizeof(*cell);
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;
}
/**
* 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, *cpus;
cpus = of_find_node_by_path("/cpus");
if (!cpus) {
pr_warn("Missing cpus node, bailing out\n");
return NULL;
}
for_each_child_of_node(cpus, cpun) {
if (of_node_cmp(cpun->type, "cpu"))
continue;
/* 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 cpun;
if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
return cpun;
}
return NULL;
}
EXPORT_SYMBOL(of_get_cpu_node);
/** Checks if the given "compat" string matches one of the strings in
* the device's "compatible" property
*/
static int __of_device_is_compatible(const struct device_node *device,
const char *compat)
{
const char* cp;
int cplen, l;
cp = __of_get_property(device, "compatible", &cplen);
if (cp == NULL)
return 0;
while (cplen > 0) {
if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
return 1;
l = strlen(cp) + 1;
cp += l;
cplen -= l;
}
return 0;
}
/** 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);
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 true 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 1 if the status property is absent or set to "okay" or "ok",
* 0 otherwise
*/
static int __of_device_is_available(const struct device_node *device)
{
const char *status;
int statlen;
status = __of_get_property(device, "status", &statlen);
if (status == NULL)
return 1;
if (statlen > 0) {
if (!strcmp(status, "okay") || !strcmp(status, "ok"))
return 1;
}
return 0;
}
/**
* of_device_is_available - check if a device is available for use
*
* @device: Node to check for availability
*
* Returns 1 if the status property is absent or set to "okay" or "ok",
* 0 otherwise
*/
int of_device_is_available(const struct device_node *device)
{
unsigned long flags;
int 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_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);
/**
* 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.
*/
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 = prev ? prev->sibling : node->child;
for (; next; next = next->sibling)
if (of_node_get(next))
break;
of_node_put(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;
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_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);
/**
* of_find_node_by_path - Find a node matching a full OF path
* @path: The full path to match
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_node_by_path(const char *path)
{
struct device_node *np = of_allnodes;
unsigned long flags;
raw_spin_lock_irqsave(&devtree_lock, flags);
for (; np; np = np->allnext) {
if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
&& of_node_get(np))
break;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return np;
}
EXPORT_SYMBOL(of_find_node_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);
np = from ? from->allnext : of_allnodes;
for (; np; np = np->allnext)
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);
np = from ? from->allnext : of_allnodes;
for (; np; np = np->allnext)
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);
np = from ? from->allnext : of_allnodes;
for (; np; np = np->allnext) {
if (type
&& !(np->type && (of_node_cmp(np->type, type) == 0)))
continue;
if (__of_device_is_compatible(np, compatible) &&
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);
np = from ? from->allnext : of_allnodes;
for (; np; np = np->allnext) {
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)
{
if (!matches)
return NULL;
while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
int match = 1;
if (matches->name[0])
match &= node->name
&& !strcmp(matches->name, node->name);
if (matches->type[0])
match &= node->type
&& !strcmp(matches->type, node->type);
if (matches->compatible[0])
match &= __of_device_is_compatible(node,
matches->compatible);
if (match)
return matches;
matches++;
}
return NULL;
}
/**
* of_match_node - Tell if an 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);
np = from ? from->allnext : of_allnodes;
for (; np; np = np->allnext) {
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;
raw_spin_lock_irqsave(&devtree_lock, flags);
for (np = of_allnodes; np; np = np->allnext)
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_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_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_read_string_index - Find and read a string from a multiple
* strings 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 string in the list of strings
* @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) in the list of strings
* contained in that property.
* 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_index(struct device_node *np, const char *propname,
int index, const char **output)
{
struct property *prop = of_find_property(np, propname, NULL);
int i = 0;
size_t l = 0, total = 0;
const char *p;
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
if (strnlen(prop->value, prop->length) >= prop->length)
return -EILSEQ;
p = prop->value;
for (i = 0; total < prop->length; total += l, p += l) {
l = strlen(p) + 1;
if (i++ == index) {
*output = p;
return 0;
}
}
return -ENODATA;
}
EXPORT_SYMBOL_GPL(of_property_read_string_index);
/**
* 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 = strlen(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_count_strings - Find and return the number of strings from a
* multiple strings property.
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
*
* Search for a property in a device tree node and retrieve the number of null
* terminated string contain in it. Returns the number of strings 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.
*/
int of_property_count_strings(struct device_node *np, const char *propname)
{
struct property *prop = of_find_property(np, propname, NULL);
int i = 0;
size_t l = 0, total = 0;
const char *p;
if (!prop)
return -EINVAL;
if (!prop->value)
return -ENODATA;
if (strnlen(prop->value, prop->length) >= prop->length)
return -EILSEQ;
p = prop->value;
for (i = 0; total < prop->length; total += l, p += l, i++)
l = strlen(p) + 1;
return i;
}
EXPORT_SYMBOL_GPL(of_property_count_strings);
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->node
* 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->node
* 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);
#if defined(CONFIG_OF_DYNAMIC)
static int of_property_notify(int action, struct device_node *np,
struct property *prop)
{
struct of_prop_reconfig pr;
pr.dn = np;
pr.prop = prop;
return of_reconfig_notify(action, &pr);
}
#else
static int of_property_notify(int action, struct device_node *np,
struct property *prop)
{
return 0;
}
#endif
/**
* of_add_property - Add a property to a node
*/
int of_add_property(struct device_node *np, struct property *prop)
{
struct property **next;
unsigned long flags;
int rc;
rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
if (rc)
return rc;
prop->next = NULL;
raw_spin_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
while (*next) {
if (strcmp(prop->name, (*next)->name) == 0) {
/* duplicate ! don't insert it */
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return -1;
}
next = &(*next)->next;
}
*next = prop;
raw_spin_unlock_irqrestore(&devtree_lock, flags);
#ifdef CONFIG_PROC_DEVICETREE
/* try to add to proc as well if it was initialized */
if (np->pde)
proc_device_tree_add_prop(np->pde, prop);
#endif /* CONFIG_PROC_DEVICETREE */
return 0;
}
/**
* 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)
{
struct property **next;
unsigned long flags;
int found = 0;
int rc;
rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
if (rc)
return rc;
raw_spin_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
while (*next) {
if (*next == prop) {
/* found the node */
*next = prop->next;
prop->next = np->deadprops;
np->deadprops = prop;
found = 1;
break;
}
next = &(*next)->next;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!found)
return -ENODEV;
#ifdef CONFIG_PROC_DEVICETREE
/* try to remove the proc node as well */
if (np->pde)
proc_device_tree_remove_prop(np->pde, prop);
#endif /* CONFIG_PROC_DEVICETREE */
return 0;
}
/*
* 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 **next, *oldprop;
unsigned long flags;
int rc, found = 0;
rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
if (rc)
return rc;
if (!newprop->name)
return -EINVAL;
oldprop = of_find_property(np, newprop->name, NULL);
if (!oldprop)
return of_add_property(np, newprop);
raw_spin_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
while (*next) {
if (*next == oldprop) {
/* found the node */
newprop->next = oldprop->next;
*next = newprop;
oldprop->next = np->deadprops;
np->deadprops = oldprop;
found = 1;
break;
}
next = &(*next)->next;
}
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (!found)
return -ENODEV;
#ifdef CONFIG_PROC_DEVICETREE
/* try to add to proc as well if it was initialized */
if (np->pde)
proc_device_tree_update_prop(np->pde, newprop, oldprop);
#endif /* CONFIG_PROC_DEVICETREE */
return 0;
}
#if defined(CONFIG_OF_DYNAMIC)
/*
* Support for dynamic device trees.
*
* On some platforms, the device tree can be manipulated at runtime.
* The routines in this section support adding, removing and changing
* device tree nodes.
*/
static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
int of_reconfig_notifier_register(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&of_reconfig_chain, nb);
}
EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
int of_reconfig_notifier_unregister(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
}
EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
int of_reconfig_notify(unsigned long action, void *p)
{
int rc;
rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
return notifier_to_errno(rc);
}
#ifdef CONFIG_PROC_DEVICETREE
static void of_add_proc_dt_entry(struct device_node *dn)
{
struct proc_dir_entry *ent;
ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
if (ent)
proc_device_tree_add_node(dn, ent);
}
#else
static void of_add_proc_dt_entry(struct device_node *dn)
{
return;
}
#endif
/**
* of_attach_node - Plug a device node into the tree and global list.
*/
int of_attach_node(struct device_node *np)
{
unsigned long flags;
int rc;
rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
if (rc)
return rc;
raw_spin_lock_irqsave(&devtree_lock, flags);
np->sibling = np->parent->child;
np->allnext = of_allnodes;
np->parent->child = np;
of_allnodes = np;
raw_spin_unlock_irqrestore(&devtree_lock, flags);
of_add_proc_dt_entry(np);
return 0;
}
#ifdef CONFIG_PROC_DEVICETREE
static void of_remove_proc_dt_entry(struct device_node *dn)
{
proc_remove(dn->pde);
}
#else
static void of_remove_proc_dt_entry(struct device_node *dn)
{
return;
}
#endif
/**
* of_detach_node - "Unplug" a node from the device tree.
*
* The caller must hold a reference to the node. The memory associated with
* the node is not freed until its refcount goes to zero.
*/
int of_detach_node(struct device_node *np)
{
struct device_node *parent;
unsigned long flags;
int rc = 0;
rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
if (rc)
return rc;
raw_spin_lock_irqsave(&devtree_lock, flags);
if (of_node_check_flag(np, OF_DETACHED)) {
/* someone already detached it */
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return rc;
}
parent = np->parent;
if (!parent) {
raw_spin_unlock_irqrestore(&devtree_lock, flags);
return rc;
}
if (of_allnodes == np)
of_allnodes = np->allnext;
else {
struct device_node *prev;
for (prev = of_allnodes;
prev->allnext != np;
prev = prev->allnext)
;
prev->allnext = np->allnext;
}
if (parent->child == np)
parent->child = np->sibling;
else {
struct device_node *prevsib;
for (prevsib = np->parent->child;
prevsib->sibling != np;
prevsib = prevsib->sibling)
;
prevsib->sibling = np->sibling;
}
of_node_set_flag(np, OF_DETACHED);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
of_remove_proc_dt_entry(np);
return rc;
}
#endif /* defined(CONFIG_OF_DYNAMIC) */
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 'aliases' node
*
* The function scans all the properties of 'aliases' node and populate
* the the global lookup table with the properties. It returns the
* number of alias_prop found, or error code in error case.
*
* @dt_alloc: An allocator that provides a virtual address to memory
* for the resulting tree
*/
void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
{
struct property *pp;
of_chosen = of_find_node_by_path("/chosen");
if (of_chosen == NULL)
of_chosen = of_find_node_by_path("/chosen@0");
if (of_chosen) {
const char *name;
name = of_get_property(of_chosen, "linux,stdout-path", NULL);
if (name)
of_stdout = of_find_node_by_path(name);
}
of_aliases = of_find_node_by_path("/aliases");
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 alias id for the given
* device_node and alias stem. It returns the alias id if find it.
*/
int of_alias_get_id(struct device_node *np, const char *stem)
{
struct alias_prop *app;
int id = -ENODEV;
mutex_lock(&of_aliases_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_aliases_mutex);
return id;
}
EXPORT_SYMBOL_GPL(of_alias_get_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_device_is_stdout_path - check if a device node matches the
* linux,stdout-path property
*
* Check if this device node matches the linux,stdout-path property
* in the chosen node. return true if yes, false otherwise.
*/
int of_device_is_stdout_path(struct device_node *dn)
{
if (!of_stdout)
return false;
return of_stdout == dn;
}
EXPORT_SYMBOL_GPL(of_device_is_stdout_path);