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
|
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#define I2C_API_FAKE_ADDR 0x7f
#define I2C_MINORS 256
struct i2c_api {
struct list_head list;
struct i2c_client *client;
};
static LIST_HEAD(i2c_api_list);
static DEFINE_SPINLOCK(i2c_api_list_lock);
static struct i2c_api *get_i2c_api(int bus_id)
{
struct i2c_api *i2c_api;
spin_lock(&i2c_api_list_lock);
list_for_each_entry(i2c_api, &i2c_api_list, list) {
if (i2c_api->client->adapter->nr == bus_id)
goto found;
}
i2c_api = NULL;
found:
spin_unlock(&i2c_api_list_lock);
return i2c_api;
}
static struct i2c_api *add_i2c_api(struct i2c_client *client)
{
struct i2c_api *i2c_api;
if (client->adapter->nr >= I2C_MINORS) {
printk(KERN_ERR "i2c_api: Out of device minors (%d)\n",
client->adapter->nr);
return NULL;
}
i2c_api = kzalloc(sizeof(*i2c_api), GFP_KERNEL);
if (!i2c_api)
return NULL;
i2c_api->client = client;
spin_lock(&i2c_api_list_lock);
list_add_tail(&i2c_api->list, &i2c_api_list);
spin_unlock(&i2c_api_list_lock);
return i2c_api;
}
static void del_i2c_api(struct i2c_api *i2c_api)
{
spin_lock(&i2c_api_list_lock);
list_del(&i2c_api->list);
spin_unlock(&i2c_api_list_lock);
kfree(i2c_api);
}
static int i2c_api_do_xfer(int bus_id, char chip_addr, char sub_addr, int mode,
char *buf, unsigned int size)
{
/** you could define more transfer mode here, implement it following. */
#define I2C_API_XFER_MODE_SEND 0x0 /* standard send */
#define I2C_API_XFER_MODE_RECV 0x1 /* standard receive */
#define I2C_API_XFER_MODE_SEND_NO_SUBADDR 0x2 /* send without sub-address */
#define I2C_API_XFER_MODE_RECV_NO_SUBADDR 0x3 /* receive without sub-address */
int ret = 0;
char *tmp;
struct i2c_api *i2c_api = get_i2c_api(bus_id);
if (!i2c_api)
return -ENODEV;
i2c_api->client->addr = chip_addr;
switch (mode) {
case I2C_API_XFER_MODE_SEND:
tmp = kmalloc(size + 1,GFP_KERNEL);
if (tmp == NULL)
return -ENOMEM;
tmp[0] = sub_addr;
memcpy(&tmp[1], buf, size);
ret = i2c_master_send(i2c_api->client, tmp, size + 1);
ret = (ret == size + 1) ? size : ret;
kfree(tmp);
break;
case I2C_API_XFER_MODE_RECV:
ret = i2c_master_send(i2c_api->client, &sub_addr, 1);
if (ret < 0)
return ret;
ret = i2c_master_recv(i2c_api->client, buf, size);
break;
case I2C_API_XFER_MODE_SEND_NO_SUBADDR:
ret = i2c_master_send(i2c_api->client, buf, size);
break;
case I2C_API_XFER_MODE_RECV_NO_SUBADDR:
ret = i2c_master_recv(i2c_api->client, buf, size);
break;
default:
return -EINVAL;
}
return ret;
}
int i2c_api_do_send(int bus_id, char chip_addr, char sub_addr, char *buf, unsigned int size)
{
return i2c_api_do_xfer(bus_id, chip_addr, sub_addr, I2C_API_XFER_MODE_SEND, buf, size);
}
int i2c_api_do_recv(int bus_id, char chip_addr, char sub_addr, char *buf, unsigned int size)
{
return i2c_api_do_xfer(bus_id, chip_addr, sub_addr, I2C_API_XFER_MODE_RECV, buf, size);
}
int i2c_api_do_send_without_subaddr(int bus_id, char chip_addr, char *buf, unsigned int size)
{
return i2c_api_do_xfer(bus_id, chip_addr, 0, I2C_API_XFER_MODE_SEND_NO_SUBADDR, buf, size);
}
int i2c_api_do_recv_without_subaddr(int bus_id, char chip_addr, char *buf, unsigned int size)
{
return i2c_api_do_xfer(bus_id, chip_addr, 0, I2C_API_XFER_MODE_RECV_NO_SUBADDR, buf, size);
}
int i2c_api_attach(struct i2c_adapter *adap)
{
struct i2c_board_info info;
struct i2c_client *client;
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "i2c_api", I2C_NAME_SIZE);
info.addr = I2C_API_FAKE_ADDR;
client = i2c_new_device(adap, &info);
if (client)
add_i2c_api(client);
printk(KERN_INFO "i2c_api_attach adap[%d]\n", adap->nr);
return 0;
}
int i2c_api_detach(struct i2c_adapter *adap)
{
struct i2c_api *i2c_api;
i2c_api = get_i2c_api(adap->nr);
if (i2c_api)
del_i2c_api(i2c_api);
return 0;
}
static const unsigned short normal_addr[] = { I2C_API_FAKE_ADDR, I2C_CLIENT_END };
static const unsigned short ignore[] = { I2C_CLIENT_END };
/*static struct i2c_client_address_data addr_data =
{
.normal_i2c = normal_addr,
.probe = ignore,
.ignore = ignore,
.forces = NULL,
};*/
static const struct i2c_device_id id[] = {
{"I2C-API", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, id);
static struct i2c_driver i2c_api_driver = {
.id_table = id,
.attach_adapter = i2c_api_attach,
.detach_adapter = i2c_api_detach,
.command = NULL,
.driver = {
.name = "I2C-API",
.owner = THIS_MODULE,
},
//.address_data = &addr_data,
};
static int __init i2c_api_init(void)
{
int ret = i2c_add_driver(&i2c_api_driver);
if (ret) {
printk(KERN_ERR "[%s] Driver registration failed, module not inserted.\n", __func__);
return ret;
}
return 0 ;
}
static void __exit i2c_api_exit(void)
{
i2c_del_driver(&i2c_api_driver);
}
MODULE_AUTHOR("Loon, <Loonzhong@wondermedia.com.cn>");
MODULE_DESCRIPTION("I2C i2c_api Driver");
MODULE_LICENSE("GPL");
module_init(i2c_api_init);
module_exit(i2c_api_exit);
EXPORT_SYMBOL_GPL(i2c_api_do_send);
EXPORT_SYMBOL_GPL(i2c_api_do_recv);
EXPORT_SYMBOL_GPL(i2c_api_do_send_without_subaddr);
EXPORT_SYMBOL_GPL(i2c_api_do_recv_without_subaddr);
|
