linux/include/linux/fwnode.h
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   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * fwnode.h - Firmware device node object handle type definition.
   4 *
   5 * Copyright (C) 2015, Intel Corporation
   6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   7 */
   8
   9#ifndef _LINUX_FWNODE_H_
  10#define _LINUX_FWNODE_H_
  11
  12#include <linux/types.h>
  13
  14struct fwnode_operations;
  15struct device;
  16
  17struct fwnode_handle {
  18        struct fwnode_handle *secondary;
  19        const struct fwnode_operations *ops;
  20        struct device *dev;
  21};
  22
  23/**
  24 * struct fwnode_endpoint - Fwnode graph endpoint
  25 * @port: Port number
  26 * @id: Endpoint id
  27 * @local_fwnode: reference to the related fwnode
  28 */
  29struct fwnode_endpoint {
  30        unsigned int port;
  31        unsigned int id;
  32        const struct fwnode_handle *local_fwnode;
  33};
  34
  35#define NR_FWNODE_REFERENCE_ARGS        8
  36
  37/**
  38 * struct fwnode_reference_args - Fwnode reference with additional arguments
  39 * @fwnode:- A reference to the base fwnode
  40 * @nargs: Number of elements in @args array
  41 * @args: Integer arguments on the fwnode
  42 */
  43struct fwnode_reference_args {
  44        struct fwnode_handle *fwnode;
  45        unsigned int nargs;
  46        u64 args[NR_FWNODE_REFERENCE_ARGS];
  47};
  48
  49/**
  50 * struct fwnode_operations - Operations for fwnode interface
  51 * @get: Get a reference to an fwnode.
  52 * @put: Put a reference to an fwnode.
  53 * @device_is_available: Return true if the device is available.
  54 * @device_get_match_data: Return the device driver match data.
  55 * @property_present: Return true if a property is present.
  56 * @property_read_int_array: Read an array of integer properties. Return zero on
  57 *                           success, a negative error code otherwise.
  58 * @property_read_string_array: Read an array of string properties. Return zero
  59 *                              on success, a negative error code otherwise.
  60 * @get_name: Return the name of an fwnode.
  61 * @get_name_prefix: Get a prefix for a node (for printing purposes).
  62 * @get_parent: Return the parent of an fwnode.
  63 * @get_next_child_node: Return the next child node in an iteration.
  64 * @get_named_child_node: Return a child node with a given name.
  65 * @get_reference_args: Return a reference pointed to by a property, with args
  66 * @graph_get_next_endpoint: Return an endpoint node in an iteration.
  67 * @graph_get_remote_endpoint: Return the remote endpoint node of a local
  68 *                             endpoint node.
  69 * @graph_get_port_parent: Return the parent node of a port node.
  70 * @graph_parse_endpoint: Parse endpoint for port and endpoint id.
  71 * @add_links:  Called after the device corresponding to the fwnode is added
  72 *              using device_add(). The function is expected to create device
  73 *              links to all the suppliers of the device that are available at
  74 *              the time this function is called.  The function must NOT stop
  75 *              at the first failed device link if other unlinked supplier
  76 *              devices are present in the system.  This is necessary for the
  77 *              driver/bus sync_state() callbacks to work correctly.
  78 *
  79 *              For example, say Device-C depends on suppliers Device-S1 and
  80 *              Device-S2 and the dependency is listed in that order in the
  81 *              firmware.  Say, S1 gets populated from the firmware after
  82 *              late_initcall_sync().  Say S2 is populated and probed way
  83 *              before that in device_initcall(). When C is populated, if this
  84 *              add_links() function doesn't continue past a "failed linking to
  85 *              S1" and continue linking C to S2, then S2 will get a
  86 *              sync_state() callback before C is probed. This is because from
  87 *              the perspective of S2, C was never a consumer when its
  88 *              sync_state() evaluation is done. To avoid this, the add_links()
  89 *              function has to go through all available suppliers of the
  90 *              device (that corresponds to this fwnode) and link to them
  91 *              before returning.
  92 *
  93 *              If some suppliers are not yet available (indicated by an error
  94 *              return value), this function will be called again when other
  95 *              devices are added to allow creating device links to any newly
  96 *              available suppliers.
  97 *
  98 *              Return 0 if device links have been successfully created to all
  99 *              the known suppliers of this device or if the supplier
 100 *              information is not known.
 101 *
 102 *              Return -ENODEV if the suppliers needed for probing this device
 103 *              have not been registered yet (because device links can only be
 104 *              created to devices registered with the driver core).
 105 *
 106 *              Return -EAGAIN if some of the suppliers of this device have not
 107 *              been registered yet, but none of those suppliers are necessary
 108 *              for probing the device.
 109 */
 110struct fwnode_operations {
 111        struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
 112        void (*put)(struct fwnode_handle *fwnode);
 113        bool (*device_is_available)(const struct fwnode_handle *fwnode);
 114        const void *(*device_get_match_data)(const struct fwnode_handle *fwnode,
 115                                             const struct device *dev);
 116        bool (*property_present)(const struct fwnode_handle *fwnode,
 117                                 const char *propname);
 118        int (*property_read_int_array)(const struct fwnode_handle *fwnode,
 119                                       const char *propname,
 120                                       unsigned int elem_size, void *val,
 121                                       size_t nval);
 122        int
 123        (*property_read_string_array)(const struct fwnode_handle *fwnode_handle,
 124                                      const char *propname, const char **val,
 125                                      size_t nval);
 126        const char *(*get_name)(const struct fwnode_handle *fwnode);
 127        const char *(*get_name_prefix)(const struct fwnode_handle *fwnode);
 128        struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
 129        struct fwnode_handle *
 130        (*get_next_child_node)(const struct fwnode_handle *fwnode,
 131                               struct fwnode_handle *child);
 132        struct fwnode_handle *
 133        (*get_named_child_node)(const struct fwnode_handle *fwnode,
 134                                const char *name);
 135        int (*get_reference_args)(const struct fwnode_handle *fwnode,
 136                                  const char *prop, const char *nargs_prop,
 137                                  unsigned int nargs, unsigned int index,
 138                                  struct fwnode_reference_args *args);
 139        struct fwnode_handle *
 140        (*graph_get_next_endpoint)(const struct fwnode_handle *fwnode,
 141                                   struct fwnode_handle *prev);
 142        struct fwnode_handle *
 143        (*graph_get_remote_endpoint)(const struct fwnode_handle *fwnode);
 144        struct fwnode_handle *
 145        (*graph_get_port_parent)(struct fwnode_handle *fwnode);
 146        int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
 147                                    struct fwnode_endpoint *endpoint);
 148        int (*add_links)(const struct fwnode_handle *fwnode,
 149                         struct device *dev);
 150};
 151
 152#define fwnode_has_op(fwnode, op)                               \
 153        ((fwnode) && (fwnode)->ops && (fwnode)->ops->op)
 154#define fwnode_call_int_op(fwnode, op, ...)                             \
 155        (fwnode ? (fwnode_has_op(fwnode, op) ?                          \
 156                   (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : -ENXIO) : \
 157         -EINVAL)
 158
 159#define fwnode_call_bool_op(fwnode, op, ...)            \
 160        (fwnode_has_op(fwnode, op) ?                    \
 161         (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : false)
 162
 163#define fwnode_call_ptr_op(fwnode, op, ...)             \
 164        (fwnode_has_op(fwnode, op) ?                    \
 165         (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : NULL)
 166#define fwnode_call_void_op(fwnode, op, ...)                            \
 167        do {                                                            \
 168                if (fwnode_has_op(fwnode, op))                          \
 169                        (fwnode)->ops->op(fwnode, ## __VA_ARGS__);      \
 170        } while (false)
 171#define get_dev_from_fwnode(fwnode)     get_device((fwnode)->dev)
 172
 173extern u32 fw_devlink_get_flags(void);
 174void fw_devlink_pause(void);
 175void fw_devlink_resume(void);
 176
 177#endif
 178