u-boot/include/dm/of_access.h
Jens Wiklander 61fba0faba ofnode: add ofnode_by_prop_value()
Adds ofnode_by_prop_value() to search for nodes with a given property
and value, an ofnode version of fdt_node_offset_by_prop_value().

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
2018-09-18 08:12:21 -06:00

434 lines
15 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Originally from Linux v4.9
* Copyright (C) 1996-2005 Paul Mackerras.
*
* Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp.
* Updates for SPARC64 by David S. Miller
* Derived from PowerPC and Sparc prom.h files by Stephen Rothwell, IBM Corp.
*
* Copyright (c) 2017 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* Modified for U-Boot
* Copyright (c) 2017 Google, Inc
*/
#ifndef _DM_OF_ACCESS_H
#define _DM_OF_ACCESS_H
#include <dm/of.h>
/**
* of_find_all_nodes - Get next node in global list
* @prev: Previous node or NULL to start iteration
* of_node_put() will be called on it
*
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
*/
struct device_node *of_find_all_nodes(struct device_node *prev);
#define for_each_of_allnodes_from(from, dn) \
for (dn = of_find_all_nodes(from); dn; dn = of_find_all_nodes(dn))
#define for_each_of_allnodes(dn) for_each_of_allnodes_from(NULL, dn)
/* Dummy functions to mirror Linux. These are not used in U-Boot */
#define of_node_get(x) (x)
static inline void of_node_put(const struct device_node *np) { }
/**
* of_n_addr_cells() - Get the number of address cells for a node
*
* This walks back up the tree to find the closest #address-cells property
* which controls the given node.
*
* @np: Node pointer to check
* @return number of address cells this node uses
*/
int of_n_addr_cells(const struct device_node *np);
/**
* of_n_size_cells() - Get the number of size cells for a node
*
* This walks back up the tree to find the closest #size-cells property
* which controls the given node.
*
* @np: Node pointer to check
* @return number of size cells this node uses
*/
int of_n_size_cells(const struct device_node *np);
/**
* of_simple_addr_cells() - Get the address cells property in a node
*
* This function matches fdt_address_cells().
*
* @np: Node pointer to check
* @return value of #address-cells property in this node, or 2 if none
*/
int of_simple_addr_cells(const struct device_node *np);
/**
* of_simple_size_cells() - Get the size cells property in a node
*
* This function matches fdt_size_cells().
*
* @np: Node pointer to check
* @return value of #size-cells property in this node, or 2 if none
*/
int of_simple_size_cells(const struct device_node *np);
/**
* of_find_property() - find a property in a node
*
* @np: Pointer to device node holding property
* @name: Name of property
* @lenp: If non-NULL, returns length of property
* @return pointer to property, or NULL if not found
*/
struct property *of_find_property(const struct device_node *np,
const char *name, int *lenp);
/**
* of_get_property() - get a property value
*
* Find a property with a given name for a given node and return the value.
*
* @np: Pointer to device node holding property
* @name: Name of property
* @lenp: If non-NULL, returns length of property
* @return pointer to property value, or NULL if not found
*/
const void *of_get_property(const struct device_node *np, const char *name,
int *lenp);
/**
* 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.
*
* @return 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
*/
int of_device_is_compatible(const struct device_node *np, const char *compat,
const char *type, const char *name);
/**
* of_device_is_available() - check if a device is available for use
*
* @device: Node to check for availability
*
* @return true if the status property is absent or set to "okay", false
* otherwise
*/
bool of_device_is_available(const struct device_node *np);
/**
* of_get_parent() - Get a node's parent, if any
*
* @node: Node to check
* @eturns a node pointer, or NULL if none
*/
struct device_node *of_get_parent(const struct device_node *np);
/**
* 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. Can be NULL
*
* Valid paths:
* /foo/bar Full path
* foo Valid alias
* foo/bar Valid alias + relative path
*
* @return a node pointer or NULL if not found
*/
struct device_node *of_find_node_opts_by_path(const char *path,
const char **opts);
static inline struct device_node *of_find_node_by_path(const char *path)
{
return of_find_node_opts_by_path(path, NULL);
}
/**
* of_find_compatible_node() - find a node based on its compatible string
*
* Find a node based on type and one of the tokens in its "compatible" property
* @from: 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.
* @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.
* @return node pointer or NULL if not found
*/
struct device_node *of_find_compatible_node(struct device_node *from,
const char *type, const char *compatible);
/**
* of_find_node_by_prop_value() - find a node with a given property value
*
* Find a node based on a property value.
* @from: 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.
* @propname: property name to check
* @propval: property value to search for
* @proplen: length of the value in propval
* @return node pointer or NULL if not found
*/
struct device_node *of_find_node_by_prop_value(struct device_node *from,
const char *propname,
const void *propval,
int proplen);
/**
* of_find_node_by_phandle() - Find a node given a phandle
*
* @handle: phandle of the node to find
*
* @return node pointer, or NULL if not found
*/
struct device_node *of_find_node_by_phandle(phandle handle);
/**
* of_read_u32() - Find and read a 32-bit integer from a property
*
* Search for a property in a device node and read a 32-bit value from
* it.
*
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @outp: pointer to return value, modified only if return value is 0.
*
* @return 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.
*/
int of_read_u32(const struct device_node *np, const char *propname, u32 *outp);
/**
* of_read_u64() - Find and read a 64-bit integer from a property
*
* Search for a property in a device node and read a 64-bit value from
* it.
*
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @outp: pointer to return value, modified only if return value is 0.
*
* @return 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.
*/
int of_read_u64(const struct device_node *np, const char *propname, u64 *outp);
/**
* of_read_u32_array() - Find and read an array of 32 bit integers
*
* Search for a property in a device node and read 32-bit value(s) from
* it.
*
* @np: device node from which the property value is to be read.
* @propname: name of the property to be searched.
* @out_values: pointer to return value, modified only if return value is 0.
* @sz: number of array elements to read
* @return 0 on success, -EINVAL if the property does not exist, -ENODATA
* if property does not have a value, and -EOVERFLOW is longer than sz.
*/
int of_read_u32_array(const struct device_node *np, const char *propname,
u32 *out_values, size_t sz);
/**
* of_property_match_string() - Find string in a list and return index
*
* This function searches a string list property and returns the index
* of a specific string value.
*
* @np: pointer to node containing string list property
* @propname: string list property name
* @string: pointer to string to search for in string list
* @return 0 on success, -EINVAL if the property does not exist, -ENODATA
* if property does not have a value, and -EOVERFLOW is longer than sz.
*/
int of_property_match_string(const struct device_node *np, const char *propname,
const char *string);
int of_property_read_string_helper(const struct device_node *np,
const char *propname, const char **out_strs,
size_t sz, int index);
/**
* 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.
*/
static inline int of_property_read_string_index(const struct device_node *np,
const char *propname,
int index, const char **output)
{
int rc = of_property_read_string_helper(np, propname, output, 1, index);
return rc < 0 ? rc : 0;
}
/**
* 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.
*/
static inline int of_property_count_strings(const struct device_node *np,
const char *propname)
{
return of_property_read_string_helper(np, propname, NULL, 0, 0);
}
/**
* of_parse_phandle - Resolve a phandle property to a device_node pointer
* @np: Pointer to device node holding phandle property
* @phandle_name: Name of property holding a phandle value
* @index: For properties holding a table of phandles, this is the index into
* the table
*
* Returns the device_node pointer with refcount incremented. Use
* of_node_put() on it when done.
*/
struct device_node *of_parse_phandle(const struct device_node *np,
const char *phandle_name, int index);
/**
* of_parse_phandle_with_args() - Find a node pointed by phandle in a list
*
* @np: pointer to a device tree node containing a list
* @list_name: property name that contains a list
* @cells_name: property name that specifies phandles' arguments count
* @index: index of a phandle to parse out
* @out_args: optional pointer to output arguments structure (will be filled)
* @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
* @list_name does not exist, -EINVAL if a phandle was not found,
* @cells_name could not be found, the arguments were truncated or there
* were too many arguments.
*
* This function is useful to parse lists of phandles and their arguments.
* Returns 0 on success and fills out_args, on error returns appropriate
* errno value.
*
* Caller is responsible to call of_node_put() on the returned out_args->np
* pointer.
*
* Example:
*
* phandle1: node1 {
* #list-cells = <2>;
* }
*
* phandle2: node2 {
* #list-cells = <1>;
* }
*
* node3 {
* list = <&phandle1 1 2 &phandle2 3>;
* }
*
* To get a device_node of the `node2' node you may call this:
* of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
*/
int of_parse_phandle_with_args(const struct device_node *np,
const char *list_name, const char *cells_name,
int index, struct of_phandle_args *out_args);
/**
* of_count_phandle_with_args() - Count the number of 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
* @return number of phandle found, -ENOENT if
* @list_name does not exist, -EINVAL if a phandle was not found,
* @cells_name could not be found, the arguments were truncated or there
* were too many arguments.
*
* Returns number of phandle found on success, on error returns appropriate
* errno value.
*
*/
int of_count_phandle_with_args(const struct device_node *np,
const char *list_name, const char *cells_name);
/**
* of_alias_scan() - Scan all properties of the 'aliases' node
*
* The function scans all the properties of the 'aliases' node and populates
* the lookup table with the properties. It returns the number of alias
* properties found, or an error code in case of failure.
*
* @return 9 if OK, -ENOMEM if not enough memory
*/
int of_alias_scan(void);
/**
* of_alias_get_id - Get alias id for the given device_node
*
* Travels the lookup table to get the alias id for the given device_node and
* alias stem.
*
* @np: Pointer to the given device_node
* @stem: Alias stem of the given device_node
* @return alias ID, if found, else -ENODEV
*/
int of_alias_get_id(const struct device_node *np, const char *stem);
/**
* of_get_stdout() - Get node to use for stdout
*
* @return node referred to by stdout-path alias, or NULL if none
*/
struct device_node *of_get_stdout(void);
#endif