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
|
/*
* Device driver for the /dev/adb device on macintoshes.
*
* Copyright (C) 1996 Paul Mackerras.
*/
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/malloc.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <asm/prom.h>
#include <asm/cuda.h>
#include <asm/uaccess.h>
#define ADB_MAJOR 56 /* major number for /dev/adb */
extern void adbdev_init(void);
struct adbdev_state {
struct cuda_request req;
};
static struct wait_queue *adb_wait;
static int adb_wait_reply(struct adbdev_state *state, struct file *file)
{
int ret = 0;
struct wait_queue wait = { current, NULL };
add_wait_queue(&adb_wait, &wait);
current->state = TASK_INTERRUPTIBLE;
while (!state->req.got_reply) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
break;
}
if (current->signal & ~current->blocked) {
ret = -ERESTARTSYS;
break;
}
schedule();
}
current->state = TASK_RUNNING;
remove_wait_queue(&adb_wait, &wait);
return ret;
}
static void adb_write_done(struct cuda_request *req)
{
if (!req->got_reply) {
req->reply_len = 0;
req->got_reply = 1;
}
wake_up_interruptible(&adb_wait);
}
static int adb_open(struct inode *inode, struct file *file)
{
struct adbdev_state *state;
if (MINOR(inode->i_rdev) > 0)
return -ENXIO;
state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
if (state == 0)
return -ENOMEM;
file->private_data = state;
state->req.reply_expected = 0;
return 0;
}
static int adb_release(struct inode *inode, struct file *file)
{
struct adbdev_state *state = file->private_data;
if (state) {
file->private_data = NULL;
if (state->req.reply_expected && !state->req.got_reply)
if (adb_wait_reply(state, file))
return 0;
kfree(state);
}
return 0;
}
static long long adb_lseek(struct file *file, long long offset, int origin)
{
return -ESPIPE;
}
static long adb_read(struct inode *inode, struct file *file,
char *buf, unsigned long count)
{
int ret;
struct adbdev_state *state = file->private_data;
if (count < 2)
return -EINVAL;
if (count > sizeof(state->req.reply))
count = sizeof(state->req.reply);
ret = verify_area(VERIFY_WRITE, buf, count);
if (ret)
return ret;
if (!state->req.reply_expected)
return 0;
ret = adb_wait_reply(state, file);
if (ret)
return ret;
ret = state->req.reply_len;
copy_to_user(buf, state->req.reply, ret);
state->req.reply_expected = 0;
return ret;
}
static long adb_write(struct inode *inode, struct file *file,
const char *buf, unsigned long count)
{
int ret;
struct adbdev_state *state = file->private_data;
if (count < 2 || count > sizeof(state->req.data))
return -EINVAL;
ret = verify_area(VERIFY_READ, buf, count);
if (ret)
return ret;
if (state->req.reply_expected && !state->req.got_reply) {
/* A previous request is still being processed.
Wait for it to finish. */
ret = adb_wait_reply(state, file);
if (ret)
return ret;
}
state->req.nbytes = count;
state->req.done = adb_write_done;
copy_from_user(state->req.data, buf, count);
state->req.reply_expected = 1;
state->req.got_reply = 0;
cuda_send_request(&state->req);
return count;
}
static struct file_operations adb_fops = {
adb_lseek,
adb_read,
adb_write,
NULL, /* no readdir */
NULL, /* no poll yet */
NULL, /* no ioctl yet */
NULL, /* no mmap */
adb_open,
adb_release
};
void adbdev_init()
{
if (register_chrdev(ADB_MAJOR, "adb", &adb_fops))
printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
}
|
