include/linux/fwnode.h

   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
  14 struct fwnode_operations;
  15 struct device;
  16
  17 struct 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  */
  29 struct 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  */
  43 struct 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  */
 110 struct 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
 173 #endif