u-boot/include/dm/ofnode.h
2017-07-29 11:43:51 -04:00

629 lines
19 KiB
C

/*
* Copyright (c) 2017 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _DM_OFNODE_H
#define _DM_OFNODE_H
/* TODO(sjg@chromium.org): Drop fdtdec.h include */
#include <fdtdec.h>
#include <dm/of.h>
/* Enable checks to protect against invalid calls */
#undef OF_CHECKS
struct resource;
/**
* ofnode - reference to a device tree node
*
* This union can hold either a straightforward pointer to a struct device_node
* in the live device tree, or an offset within the flat device tree. In the
* latter case, the pointer value is just the integer offset within the flat DT.
*
* Thus we can reference nodes in both the live tree (once available) and the
* flat tree (until then). Functions are available to translate between an
* ofnode and either an offset or a struct device_node *.
*
* The reference can also hold a null offset, in which case the pointer value
* here is NULL. This corresponds to a struct device_node * value of
* NULL, or an offset of -1.
*
* There is no ambiguity as to whether ofnode holds an offset or a node
* pointer: when the live tree is active it holds a node pointer, otherwise it
* holds an offset. The value itself does not need to be unique and in theory
* the same value could point to a valid device node or a valid offset. We
* could arrange for a unique value to be used (e.g. by making the pointer
* point to an offset within the flat device tree in the case of an offset) but
* this increases code size slightly due to the subtraction. Since it offers no
* real benefit, the approach described here seems best.
*
* For now these points use constant types, since we don't allow writing
* the DT.
*
* @np: Pointer to device node, used for live tree
* @flat_ptr: Pointer into flat device tree, used for flat tree. Note that this
* is not a really a pointer to a node: it is an offset value. See above.
*/
typedef union ofnode_union {
const struct device_node *np; /* will be used for future live tree */
long of_offset;
} ofnode;
struct ofnode_phandle_args {
ofnode node;
int args_count;
uint32_t args[OF_MAX_PHANDLE_ARGS];
};
/**
* _ofnode_to_np() - convert an ofnode to a live DT node pointer
*
* This cannot be called if the reference contains an offset.
*
* @node: Reference containing struct device_node * (possibly invalid)
* @return pointer to device node (can be NULL)
*/
static inline const struct device_node *ofnode_to_np(ofnode node)
{
#ifdef OF_CHECKS
if (!of_live_active())
return NULL;
#endif
return node.np;
}
/**
* ofnode_to_offset() - convert an ofnode to a flat DT offset
*
* This cannot be called if the reference contains a node pointer.
*
* @node: Reference containing offset (possibly invalid)
* @return DT offset (can be -1)
*/
static inline int ofnode_to_offset(ofnode node)
{
#ifdef OF_CHECKS
if (of_live_active())
return -1;
#endif
return node.of_offset;
}
/**
* ofnode_valid() - check if an ofnode is valid
*
* @return true if the reference contains a valid ofnode, false if it is NULL
*/
static inline bool ofnode_valid(ofnode node)
{
if (of_live_active())
return node.np != NULL;
else
return node.of_offset != -1;
}
/**
* offset_to_ofnode() - convert a DT offset to an ofnode
*
* @of_offset: DT offset (either valid, or -1)
* @return reference to the associated DT offset
*/
static inline ofnode offset_to_ofnode(int of_offset)
{
ofnode node;
if (of_live_active())
node.np = NULL;
else
node.of_offset = of_offset;
return node;
}
/**
* np_to_ofnode() - convert a node pointer to an ofnode
*
* @np: Live node pointer (can be NULL)
* @return reference to the associated node pointer
*/
static inline ofnode np_to_ofnode(const struct device_node *np)
{
ofnode node;
node.np = np;
return node;
}
/**
* ofnode_is_np() - check if a reference is a node pointer
*
* This function associated that if there is a valid live tree then all
* references will use it. This is because using the flat DT when the live tree
* is valid is not permitted.
*
* @node: reference to check (possibly invalid)
* @return true if the reference is a live node pointer, false if it is a DT
* offset
*/
static inline bool ofnode_is_np(ofnode node)
{
#ifdef OF_CHECKS
/*
* Check our assumption that flat tree offsets are not used when a
* live tree is in use.
*/
assert(!ofnode_valid(node) ||
(of_live_active() ? _ofnode_to_np(node)
: _ofnode_to_np(node)));
#endif
return of_live_active() && ofnode_valid(node);
}
/**
* ofnode_equal() - check if two references are equal
*
* @return true if equal, else false
*/
static inline bool ofnode_equal(ofnode ref1, ofnode ref2)
{
/* We only need to compare the contents */
return ref1.of_offset == ref2.of_offset;
}
/**
* ofnode_null() - Obtain a null ofnode
*
* This returns an ofnode which points to no node. It works both with the flat
* tree and livetree.
*/
static inline ofnode ofnode_null(void)
{
ofnode node;
if (of_live_active())
node.np = NULL;
else
node.of_offset = -1;
return node;
}
/**
* ofnode_read_u32() - Read a 32-bit integer from a property
*
* @ref: valid node reference to read property from
* @propname: name of the property to read from
* @outp: place to put value (if found)
* @return 0 if OK, -ve on error
*/
int ofnode_read_u32(ofnode node, const char *propname, u32 *outp);
/**
* ofnode_read_s32() - Read a 32-bit integer from a property
*
* @ref: valid node reference to read property from
* @propname: name of the property to read from
* @outp: place to put value (if found)
* @return 0 if OK, -ve on error
*/
static inline int ofnode_read_s32(ofnode node, const char *propname,
s32 *out_value)
{
return ofnode_read_u32(node, propname, (u32 *)out_value);
}
/**
* ofnode_read_u32_default() - Read a 32-bit integer from a property
*
* @ref: valid node reference to read property from
* @propname: name of the property to read from
* @def: default value to return if the property has no value
* @return property value, or @def if not found
*/
int ofnode_read_u32_default(ofnode ref, const char *propname, u32 def);
/**
* ofnode_read_s32_default() - Read a 32-bit integer from a property
*
* @ref: valid node reference to read property from
* @propname: name of the property to read from
* @def: default value to return if the property has no value
* @return property value, or @def if not found
*/
int ofnode_read_s32_default(ofnode node, const char *propname, s32 def);
/**
* ofnode_read_string() - Read a string from a property
*
* @ref: valid node reference to read property from
* @propname: name of the property to read
* @return string from property value, or NULL if there is no such property
*/
const char *ofnode_read_string(ofnode node, const char *propname);
/**
* ofnode_read_u32_array() - Find and read an array of 32 bit integers
*
* @node: valid node reference to read property from
* @propname: name of the property to read
* @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 ofnode_read_u32_array(ofnode node, const char *propname,
u32 *out_values, size_t sz);
/**
* ofnode_read_bool() - read a boolean value from a property
*
* @node: valid node reference to read property from
* @propname: name of property to read
* @return true if property is present (meaning true), false if not present
*/
bool ofnode_read_bool(ofnode node, const char *propname);
/**
* ofnode_find_subnode() - find a named subnode of a parent node
*
* @node: valid reference to parent node
* @subnode_name: name of subnode to find
* @return reference to subnode (which can be invalid if there is no such
* subnode)
*/
ofnode ofnode_find_subnode(ofnode node, const char *subnode_name);
/**
* ofnode_first_subnode() - find the first subnode of a parent node
*
* @node: valid reference to a valid parent node
* @return reference to the first subnode (which can be invalid if the parent
* node has no subnodes)
*/
ofnode ofnode_first_subnode(ofnode node);
/**
* ofnode_next_subnode() - find the next sibling of a subnode
*
* @node: valid reference to previous node (sibling)
* @return reference to the next subnode (which can be invalid if the node
* has no more siblings)
*/
ofnode ofnode_next_subnode(ofnode node);
/**
* ofnode_get_name() - get the name of a node
*
* @node: valid node to look up
* @return name or node
*/
const char *ofnode_get_name(ofnode node);
/**
* ofnode_read_size() - read the size of a property
*
* @node: node to check
* @propname: property to check
* @return size of property if present, or -EINVAL if not
*/
int ofnode_read_size(ofnode node, const char *propname);
/**
* ofnode_get_addr_index() - get an address from a node
*
* This reads the register address from a node
*
* @node: node to read from
* @index: Index of address to read (0 for first)
* @return address, or FDT_ADDR_T_NONE if not present or invalid
*/
phys_addr_t ofnode_get_addr_index(ofnode node, int index);
/**
* ofnode_get_addr() - get an address from a node
*
* This reads the register address from a node
*
* @node: node to read from
* @return address, or FDT_ADDR_T_NONE if not present or invalid
*/
phys_addr_t ofnode_get_addr(ofnode node);
/**
* ofnode_stringlist_search() - find a string in a string list and return index
*
* Note that it is possible for this function to succeed on property values
* that are not NUL-terminated. That's because the function will stop after
* finding the first occurrence of @string. This can for example happen with
* small-valued cell properties, such as #address-cells, when searching for
* the empty string.
*
* @node: node to check
* @propname: name of the property containing the string list
* @string: string to look up in the string list
*
* @return:
* the index of the string in the list of strings
* -ENODATA if the property is not found
* -EINVAL on some other error
*/
int ofnode_stringlist_search(ofnode node, const char *propname,
const char *string);
/**
* ofnode_read_string_index() - obtain an indexed string from a string list
*
* Note that this will successfully extract strings from properties with
* non-NUL-terminated values. For example on small-valued cell properties
* this function will return the empty string.
*
* If non-NULL, the length of the string (on success) or a negative error-code
* (on failure) will be stored in the integer pointer to by lenp.
*
* @node: node to check
* @propname: name of the property containing the string list
* @index: index of the string to return
* @lenp: return location for the string length or an error code on failure
*
* @return:
* length of string, if found or -ve error value if not found
*/
int ofnode_read_string_index(ofnode node, const char *propname, int index,
const char **outp);
/**
* ofnode_read_string_count() - find the number of strings in a string list
*
* @node: node to check
* @propname: name of the property containing the string list
* @return:
* number of strings in the list, or -ve error value if not found
*/
int ofnode_read_string_count(ofnode node, const char *property);
/**
* ofnode_parse_phandle_with_args() - Find a node pointed by phandle in a list
*
* 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:
* ofnode_parse_phandle_with_args(node3, "list", "#list-cells", 0, 1, &args);
*
* @node: device tree node containing a list
* @list_name: property name that contains a list
* @cells_name: property name that specifies phandles' arguments count
* @cells_count: Cell count to use if @cells_name is NULL
* @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.
*/
int ofnode_parse_phandle_with_args(ofnode node, const char *list_name,
const char *cells_name, int cell_count,
int index,
struct ofnode_phandle_args *out_args);
/**
* ofnode_count_phandle_with_args() - Count number of phandle in a list
*
* This function is useful to count phandles into a list.
* Returns number of phandle on success, on error returns appropriate
* errno value.
*
* @node: 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 on success, -ENOENT if @list_name does not
* exist, -EINVAL if a phandle was not found, @cells_name could not
* be found.
*/
int ofnode_count_phandle_with_args(ofnode node, const char *list_name,
const char *cells_name);
/**
* ofnode_path() - find a node by full path
*
* @path: Full path to node, e.g. "/bus/spi@1"
* @return reference to the node found. Use ofnode_valid() to check if it exists
*/
ofnode ofnode_path(const char *path);
/**
* ofnode_get_chosen_prop() - get the value of a chosen property
*
* This looks for a property within the /chosen node and returns its value
*
* @propname: Property name to look for
*/
const char *ofnode_get_chosen_prop(const char *propname);
/**
* ofnode_get_chosen_node() - get the chosen node
*
* @return the chosen node if present, else ofnode_null()
*/
ofnode ofnode_get_chosen_node(const char *name);
struct display_timing;
/**
* ofnode_decode_display_timing() - decode display timings
*
* Decode display timings from the supplied 'display-timings' node.
* See doc/device-tree-bindings/video/display-timing.txt for binding
* information.
*
* @node 'display-timing' node containing the timing subnodes
* @index Index number to read (0=first timing subnode)
* @config Place to put timings
* @return 0 if OK, -FDT_ERR_NOTFOUND if not found
*/
int ofnode_decode_display_timing(ofnode node, int index,
struct display_timing *config);
/**
* ofnode_get_property()- - get a pointer to the value of a node property
*
* @node: node to read
* @propname: property to read
* @lenp: place to put length on success
* @return pointer to property, or NULL if not found
*/
const void *ofnode_get_property(ofnode node, const char *propname, int *lenp);
/**
* ofnode_is_available() - check if a node is marked available
*
* @node: node to check
* @return true if node's 'status' property is "okay" (or is missing)
*/
bool ofnode_is_available(ofnode node);
/**
* ofnode_get_addr_size() - get address and size from a property
*
* This does no address translation. It simply reads an property that contains
* an address and a size value, one after the other.
*
* @node: node to read from
* @propname: property to read
* @sizep: place to put size value (on success)
* @return address value, or FDT_ADDR_T_NONE on error
*/
phys_addr_t ofnode_get_addr_size(ofnode node, const char *propname,
phys_size_t *sizep);
/**
* ofnode_read_u8_array_ptr() - find an 8-bit array
*
* Look up a property in a node and return a pointer to its contents as a
* byte array of given length. The property must have at least enough data
* for the array (count bytes). It may have more, but this will be ignored.
* The data is not copied.
*
* @node node to examine
* @propname name of property to find
* @sz number of array elements
* @return pointer to byte array if found, or NULL if the property is not
* found or there is not enough data
*/
const uint8_t *ofnode_read_u8_array_ptr(ofnode node, const char *propname,
size_t sz);
/**
* ofnode_read_pci_addr() - look up a PCI address
*
* Look at an address property in a node and return the PCI address which
* corresponds to the given type in the form of fdt_pci_addr.
* The property must hold one fdt_pci_addr with a lengh.
*
* @node node to examine
* @type pci address type (FDT_PCI_SPACE_xxx)
* @propname name of property to find
* @addr returns pci address in the form of fdt_pci_addr
* @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
* format of the property was invalid, -ENXIO if the requested
* address type was not found
*/
int ofnode_read_pci_addr(ofnode node, enum fdt_pci_space type,
const char *propname, struct fdt_pci_addr *addr);
/**
* ofnode_read_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.
*
* @node: Node to check
* @return number of address cells this node uses
*/
int ofnode_read_addr_cells(ofnode node);
/**
* ofnode_read_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.
*
* @node: Node to check
* @return number of size cells this node uses
*/
int ofnode_read_size_cells(ofnode node);
/**
* ofnode_read_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 ofnode_read_simple_addr_cells(ofnode node);
/**
* ofnode_read_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 ofnode_read_simple_size_cells(ofnode node);
/**
* ofnode_pre_reloc() - check if a node should be bound before relocation
*
* Device tree nodes can be marked as needing-to-be-bound in the loader stages
* via special device tree properties.
*
* Before relocation this function can be used to check if nodes are required
* in either SPL or TPL stages.
*
* After relocation and jumping into the real U-Boot binary it is possible to
* determine if a node was bound in one of SPL/TPL stages.
*
* There are 3 settings currently in use
* -
* - u-boot,dm-pre-reloc: legacy and indicates any of TPL or SPL
* Existing platforms only use it to indicate nodes needed in
* SPL. Should probably be replaced by u-boot,dm-spl for
* new platforms.
*
* @node: node to check
* @eturns true if node is needed in SPL/TL, false otherwise
*/
bool ofnode_pre_reloc(ofnode node);
int ofnode_read_resource(ofnode node, uint index, struct resource *res);
#endif