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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface (SCMI) Message Protocol bus layer
*
* Copyright (C) 2018 ARM Ltd.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/types.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
#include "common.h"
static DEFINE_IDA(scmi_bus_id);
static DEFINE_IDR(scmi_protocols);
static DEFINE_SPINLOCK(protocol_lock);
static const struct scmi_device_id *
scmi_dev_match_id(struct scmi_device *scmi_dev, struct scmi_driver *scmi_drv)
{
const struct scmi_device_id *id = scmi_drv->id_table;
if (!id)
return NULL;
for (; id->protocol_id; id++)
if (id->protocol_id == scmi_dev->protocol_id)
return id;
return NULL;
}
static int scmi_dev_match(struct device *dev, struct device_driver *drv)
{
struct scmi_driver *scmi_drv = to_scmi_driver(drv);
struct scmi_device *scmi_dev = to_scmi_dev(dev);
const struct scmi_device_id *id;
id = scmi_dev_match_id(scmi_dev, scmi_drv);
if (id)
return 1;
return 0;
}
static int scmi_protocol_init(int protocol_id, struct scmi_handle *handle)
{
scmi_prot_init_fn_t fn = idr_find(&scmi_protocols, protocol_id);
if (unlikely(!fn))
return -EINVAL;
return fn(handle);
}
static int scmi_dev_probe(struct device *dev)
{
struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
struct scmi_device *scmi_dev = to_scmi_dev(dev);
const struct scmi_device_id *id;
int ret;
id = scmi_dev_match_id(scmi_dev, scmi_drv);
if (!id)
return -ENODEV;
if (!scmi_dev->handle)
return -EPROBE_DEFER;
ret = scmi_protocol_init(scmi_dev->protocol_id, scmi_dev->handle);
if (ret)
return ret;
return scmi_drv->probe(scmi_dev);
}
static int scmi_dev_remove(struct device *dev)
{
struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
struct scmi_device *scmi_dev = to_scmi_dev(dev);
if (scmi_drv->remove)
scmi_drv->remove(scmi_dev);
return 0;
}
static struct bus_type scmi_bus_type = {
.name = "scmi_protocol",
.match = scmi_dev_match,
.probe = scmi_dev_probe,
.remove = scmi_dev_remove,
};
int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
const char *mod_name)
{
int retval;
driver->driver.bus = &scmi_bus_type;
driver->driver.name = driver->name;
driver->driver.owner = owner;
driver->driver.mod_name = mod_name;
retval = driver_register(&driver->driver);
if (!retval)
pr_debug("registered new scmi driver %s\n", driver->name);
return retval;
}
EXPORT_SYMBOL_GPL(scmi_driver_register);
void scmi_driver_unregister(struct scmi_driver *driver)
{
driver_unregister(&driver->driver);
}
EXPORT_SYMBOL_GPL(scmi_driver_unregister);
static void scmi_device_release(struct device *dev)
{
kfree(to_scmi_dev(dev));
}
struct scmi_device *
scmi_device_create(struct device_node *np, struct device *parent, int protocol)
{
int id, retval;
struct scmi_device *scmi_dev;
scmi_dev = kzalloc(sizeof(*scmi_dev), GFP_KERNEL);
if (!scmi_dev)
return NULL;
id = ida_simple_get(&scmi_bus_id, 1, 0, GFP_KERNEL);
if (id < 0) {
kfree(scmi_dev);
return NULL;
}
scmi_dev->id = id;
scmi_dev->protocol_id = protocol;
scmi_dev->dev.parent = parent;
scmi_dev->dev.of_node = np;
scmi_dev->dev.bus = &scmi_bus_type;
scmi_dev->dev.release = scmi_device_release;
dev_set_name(&scmi_dev->dev, "scmi_dev.%d", id);
retval = device_register(&scmi_dev->dev);
if (retval)
goto put_dev;
return scmi_dev;
put_dev:
put_device(&scmi_dev->dev);
ida_simple_remove(&scmi_bus_id, id);
return NULL;
}
void scmi_device_destroy(struct scmi_device *scmi_dev)
{
scmi_handle_put(scmi_dev->handle);
ida_simple_remove(&scmi_bus_id, scmi_dev->id);
device_unregister(&scmi_dev->dev);
}
void scmi_set_handle(struct scmi_device *scmi_dev)
{
scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
}
int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn)
{
int ret;
spin_lock(&protocol_lock);
ret = idr_alloc(&scmi_protocols, fn, protocol_id, protocol_id + 1,
GFP_ATOMIC);
spin_unlock(&protocol_lock);
if (ret != protocol_id)
pr_err("unable to allocate SCMI idr slot, err %d\n", ret);
return ret;
}
EXPORT_SYMBOL_GPL(scmi_protocol_register);
void scmi_protocol_unregister(int protocol_id)
{
spin_lock(&protocol_lock);
idr_remove(&scmi_protocols, protocol_id);
spin_unlock(&protocol_lock);
}
EXPORT_SYMBOL_GPL(scmi_protocol_unregister);
static int __scmi_devices_unregister(struct device *dev, void *data)
{
struct scmi_device *scmi_dev = to_scmi_dev(dev);
scmi_device_destroy(scmi_dev);
return 0;
}
static void scmi_devices_unregister(void)
{
bus_for_each_dev(&scmi_bus_type, NULL, NULL, __scmi_devices_unregister);
}
static int __init scmi_bus_init(void)
{
int retval;
retval = bus_register(&scmi_bus_type);
if (retval)
pr_err("scmi protocol bus register failed (%d)\n", retval);
return retval;
}
subsys_initcall(scmi_bus_init);
static void __exit scmi_bus_exit(void)
{
scmi_devices_unregister();
bus_unregister(&scmi_bus_type);
ida_destroy(&scmi_bus_id);
}
module_exit(scmi_bus_exit);
|
