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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 
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_get_match_data: Return the device driver match data.
54  * @property_present: Return true if a property is present.
55  * @property_read_integer_array: Read an array of integer properties. Return
56  *				 zero on success, a negative error code
57  *				 otherwise.
58  * @property_read_string_array: Read an array of string properties. Return zero
59  *				on success, a negative error code otherwise.
60  * @get_parent: Return the parent of an fwnode.
61  * @get_next_child_node: Return the next child node in an iteration.
62  * @get_named_child_node: Return a child node with a given name.
63  * @get_reference_args: Return a reference pointed to by a property, with args
64  * @graph_get_next_endpoint: Return an endpoint node in an iteration.
65  * @graph_get_remote_endpoint: Return the remote endpoint node of a local
66  *			       endpoint node.
67  * @graph_get_port_parent: Return the parent node of a port node.
68  * @graph_parse_endpoint: Parse endpoint for port and endpoint id.
69  * @add_links:	Called after the device corresponding to the fwnode is added
70  *		using device_add(). The function is expected to create device
71  *		links to all the suppliers of the device that are available at
72  *		the time this function is called.  The function must NOT stop
73  *		at the first failed device link if other unlinked supplier
74  *		devices are present in the system.  This is necessary for the
75  *		driver/bus sync_state() callbacks to work correctly.
76  *
77  *		For example, say Device-C depends on suppliers Device-S1 and
78  *		Device-S2 and the dependency is listed in that order in the
79  *		firmware.  Say, S1 gets populated from the firmware after
80  *		late_initcall_sync().  Say S2 is populated and probed way
81  *		before that in device_initcall(). When C is populated, if this
82  *		add_links() function doesn't continue past a "failed linking to
83  *		S1" and continue linking C to S2, then S2 will get a
84  *		sync_state() callback before C is probed. This is because from
85  *		the perspective of S2, C was never a consumer when its
86  *		sync_state() evaluation is done. To avoid this, the add_links()
87  *		function has to go through all available suppliers of the
88  *		device (that corresponds to this fwnode) and link to them
89  *		before returning.
90  *
91  *		If some suppliers are not yet available (indicated by an error
92  *		return value), this function will be called again when other
93  *		devices are added to allow creating device links to any newly
94  *		available suppliers.
95  *
96  *		Return 0 if device links have been successfully created to all
97  *		the known suppliers of this device or if the supplier
98  *		information is not known.
99  *
100  *		Return -ENODEV if the suppliers needed for probing this device
101  *		have not been registered yet (because device links can only be
102  *		created to devices registered with the driver core).
103  *
104  *		Return -EAGAIN if some of the suppliers of this device have not
105  *		been registered yet, but none of those suppliers are necessary
106  *		for probing the device.
107  */
108 struct fwnode_operations {
109 	struct fwnode_handle *(*get)(struct fwnode_handle *fwnode);
110 	void (*put)(struct fwnode_handle *fwnode);
111 	bool (*device_is_available)(const struct fwnode_handle *fwnode);
112 	const void *(*device_get_match_data)(const struct fwnode_handle *fwnode,
113 					     const struct device *dev);
114 	bool (*property_present)(const struct fwnode_handle *fwnode,
115 				 const char *propname);
116 	int (*property_read_int_array)(const struct fwnode_handle *fwnode,
117 				       const char *propname,
118 				       unsigned int elem_size, void *val,
119 				       size_t nval);
120 	int
121 	(*property_read_string_array)(const struct fwnode_handle *fwnode_handle,
122 				      const char *propname, const char **val,
123 				      size_t nval);
124 	struct fwnode_handle *(*get_parent)(const struct fwnode_handle *fwnode);
125 	struct fwnode_handle *
126 	(*get_next_child_node)(const struct fwnode_handle *fwnode,
127 			       struct fwnode_handle *child);
128 	struct fwnode_handle *
129 	(*get_named_child_node)(const struct fwnode_handle *fwnode,
130 				const char *name);
131 	int (*get_reference_args)(const struct fwnode_handle *fwnode,
132 				  const char *prop, const char *nargs_prop,
133 				  unsigned int nargs, unsigned int index,
134 				  struct fwnode_reference_args *args);
135 	struct fwnode_handle *
136 	(*graph_get_next_endpoint)(const struct fwnode_handle *fwnode,
137 				   struct fwnode_handle *prev);
138 	struct fwnode_handle *
139 	(*graph_get_remote_endpoint)(const struct fwnode_handle *fwnode);
140 	struct fwnode_handle *
141 	(*graph_get_port_parent)(struct fwnode_handle *fwnode);
142 	int (*graph_parse_endpoint)(const struct fwnode_handle *fwnode,
143 				    struct fwnode_endpoint *endpoint);
144 	int (*add_links)(const struct fwnode_handle *fwnode,
145 			 struct device *dev);
146 };
147 
148 #define fwnode_has_op(fwnode, op)				\
149 	((fwnode) && (fwnode)->ops && (fwnode)->ops->op)
150 #define fwnode_call_int_op(fwnode, op, ...)				\
151 	(fwnode ? (fwnode_has_op(fwnode, op) ?				\
152 		   (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : -ENXIO) : \
153 	 -EINVAL)
154 
155 #define fwnode_call_bool_op(fwnode, op, ...)		\
156 	(fwnode_has_op(fwnode, op) ?			\
157 	 (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : false)
158 
159 #define fwnode_call_ptr_op(fwnode, op, ...)		\
160 	(fwnode_has_op(fwnode, op) ?			\
161 	 (fwnode)->ops->op(fwnode, ## __VA_ARGS__) : NULL)
162 #define fwnode_call_void_op(fwnode, op, ...)				\
163 	do {								\
164 		if (fwnode_has_op(fwnode, op))				\
165 			(fwnode)->ops->op(fwnode, ## __VA_ARGS__);	\
166 	} while (false)
167 #define get_dev_from_fwnode(fwnode)	get_device((fwnode)->dev)
168 
169 #endif
170