// SPDX-License-Identifier: GPL-2.0+
/*
* drivers/of/property.c - Procedures for accessing and interpreting
* Devicetree properties and graphs.
*
* Initially created by copying procedures from drivers/of/base.c. This
* file contains the OF property as well as the OF graph interface
* functions.
*
* 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.
*/
#define pr_fmt(fmt) "OF: " fmt
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
#include <linux/string.h>
#include "of_private.h"
/**
* 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 %pOF is not a multiple of %d\n",
propname, np, 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.
* @min: minimum allowed length of property value
* @max: maximum allowed length of property value (0 means unlimited)
* @len: if !=NULL, actual length is written to here
*
* 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 is too small or too large.
*
*/
static void *of_find_property_value_of_size(const struct device_node *np,
const char *propname, u32 min, u32 max, size_t *len)
{
struct property *prop = of_find_property(np, propname, NULL);
if (!prop)
return ERR_PTR(-EINVAL);
if (!prop->value)
return ERR_PTR(-ENODATA);
if (prop->length < min)
return ERR_PTR(-EOVERFLOW);
if (max && prop->length > max)
return ERR_PTR(-EOVERFLOW);
if (len)
*len = prop->length;
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)),
0,
NULL);
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_u64_index - Find and read a u64 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 u64 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 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_index(const struct device_node *np,
const char *propname,
u32 index, u64 *out_value)
{
const u64 *val = of_find_property_value_of_size(np, propname,
((index + 1) * sizeof(*out_value)),
0, NULL);
if (IS_ERR(val))
return PTR_ERR(val);
*out_value = be64_to_cpup(((__be64 *)val) + index);
return 0;
}
EXPORT_SYMBOL_GPL(of_property_read_u64_index);
/**
* of_property_read_variable_u8_array - Find and read an array of u8 from a
* property, with bounds on the minimum and maximum array size.
*
* @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_min: minimum number of array elements to read
* @sz_max: maximum number of array elements to read, if zero there is no
* upper limit on the number of elements in the dts entry but only
* sz_min will be read.
*
* Search for a property in a device node and read 8-bit value(s) from
* it. Returns number of elements read on success, -EINVAL if the property
* does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
* if the property data is smaller than sz_min or longer than sz_max.
*
* 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_variable_u8_array(const struct device_node *np,
const char *propname, u8 *out_values,
size_t sz_min, size_t sz_max)
{
size_t sz, count;
const u8 *val = of_find_property_value_of_size(np, propname,
(sz_min * sizeof