1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/*
* Copyright (c) 2013 Google, Inc
*
* (C) Copyright 2012
* Pavel Herrmann <morpheus.ibis@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _DM_UCLASS_H
#define _DM_UCLASS_H
#include <dm/uclass-id.h>
#include <linux/list.h>
/**
* struct uclass - a U-Boot drive class, collecting together similar drivers
*
* A uclass provides an interface to a particular function, which is
* implemented by one or more drivers. Every driver belongs to a uclass even
* if it is the only driver in that uclass. An example uclass is GPIO, which
* provides the ability to change read inputs, set and clear outputs, etc.
* There may be drivers for on-chip SoC GPIO banks, I2C GPIO expanders and
* PMIC IO lines, all made available in a unified way through the uclass.
*
* @priv: Private data for this uclass
* @uc_drv: The driver for the uclass itself, not to be confused with a
* 'struct driver'
* @dev_head: List of devices in this uclass (devices are attached to their
* uclass when their bind method is called)
* @sibling_node: Next uclass in the linked list of uclasses
*/
struct uclass {
void *priv;
struct uclass_driver *uc_drv;
struct list_head dev_head;
struct list_head sibling_node;
};
struct udevice;
/**
* struct uclass_driver - Driver for the uclass
*
* A uclass_driver provides a consistent interface to a set of related
* drivers.
*
* @name: Name of uclass driver
* @id: ID number of this uclass
* @post_bind: Called after a new device is bound to this uclass
* @pre_unbind: Called before a device is unbound from this uclass
* @post_probe: Called after a new device is probed
* @pre_remove: Called before a device is removed
* @init: Called to set up the uclass
* @destroy: Called to destroy the uclass
* @priv_auto_alloc_size: If non-zero this is the size of the private data
* to be allocated in the uclass's ->priv pointer. If zero, then the uclass
* driver is responsible for allocating any data required.
* @per_device_auto_alloc_size: Each device can hold private data owned
* by the uclass. If required this will be automatically allocated if this
* value is non-zero.
* @ops: Uclass operations, providing the consistent interface to devices
* within the uclass.
*/
struct uclass_driver {
const char *name;
enum uclass_id id;
int (*post_bind)(struct udevice *dev);
int (*pre_unbind)(struct udevice *dev);
int (*post_probe)(struct udevice *dev);
int (*pre_remove)(struct udevice *dev);
int (*init)(struct uclass *class);
int (*destroy)(struct uclass *class);
int priv_auto_alloc_size;
int per_device_auto_alloc_size;
const void *ops;
};
/* Declare a new uclass_driver */
#define UCLASS_DRIVER(__name) \
ll_entry_declare(struct uclass_driver, __name, uclass)
/**
* uclass_get() - Get a uclass based on an ID, creating it if needed
*
* Every uclass is identified by an ID, a number from 0 to n-1 where n is
* the number of uclasses. This function allows looking up a uclass by its
* ID.
*
* @key: ID to look up
* @ucp: Returns pointer to uclass (there is only one per ID)
* @return 0 if OK, -ve on error
*/
int uclass_get(enum uclass_id key, struct uclass **ucp);
/**
* uclass_get_device() - Get a uclass device based on an ID and index
*
* The device is probed to activate it ready for use.
*
* id: ID to look up
* @index: Device number within that uclass (0=first)
* @devp: Returns pointer to device (there is only one per for each ID)
* @return 0 if OK, -ve on error
*/
int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
/**
* uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
*
* If an active device has this sequence it will be returned. If there is no
* such device then this will check for a device that is requesting this
* sequence.
*
* The device is probed to activate it ready for use.
*
* @id: ID to look up
* @seq: Sequence number to find (0=first)
* @devp: Returns pointer to device (there is only one for each seq)
* @return 0 if OK, -ve on error
*/
int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
/**
* uclass_get_device_by_of_offset() - Get a uclass device by device tree node
*
* This searches the devices in the uclass for one attached to the given
* device tree node.
*
* The device is probed to activate it ready for use.
*
* @id: ID to look up
* @node: Device tree offset to search for (if -ve then -ENODEV is returned)
* @devp: Returns pointer to device (there is only one for each node)
* @return 0 if OK, -ve on error
*/
int uclass_get_device_by_of_offset(enum uclass_id id, int node,
struct udevice **devp);
/**
* uclass_first_device() - Get the first device in a uclass
*
* @id: Uclass ID to look up
* @devp: Returns pointer to the first device in that uclass, or NULL if none
* @return 0 if OK (found or not found), -1 on error
*/
int uclass_first_device(enum uclass_id id, struct udevice **devp);
/**
* uclass_next_device() - Get the next device in a uclass
*
* @devp: On entry, pointer to device to lookup. On exit, returns pointer
* to the next device in the same uclass, or NULL if none
* @return 0 if OK (found or not found), -1 on error
*/
int uclass_next_device(struct udevice **devp);
/**
* uclass_resolve_seq() - Resolve a device's sequence number
*
* On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a
* sequence number automatically, or >= 0 to select a particular number.
* If the requested sequence number is in use, then this device will
* be allocated another one.
*
* Note that the device's seq value is not changed by this function.
*
* @dev: Device for which to allocate sequence number
* @return sequence number allocated, or -ve on error
*/
int uclass_resolve_seq(struct udevice *dev);
/**
* uclass_foreach_dev() - Helper function to iteration through devices
*
* This creates a for() loop which works through the available devices in
* a uclass in order from start to end.
*
* @pos: struct udevice * to hold the current device. Set to NULL when there
* are no more devices.
* @uc: uclass to scan
*/
#define uclass_foreach_dev(pos, uc) \
for (pos = list_entry((&(uc)->dev_head)->next, typeof(*pos), \
uclass_node); \
prefetch(pos->uclass_node.next), \
&pos->uclass_node != (&(uc)->dev_head); \
pos = list_entry(pos->uclass_node.next, typeof(*pos), \
uclass_node))
#endif
|