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
|
/*
* Copyright (C) 2012 CERN (www.cern.ch)
* Author: Alessandro Rubini <rubini@gnudd.com>
*
* Released according to the GNU GPL, version 2 or any later version.
*
* This work is part of the White Rabbit project, a research effort led
* by CERN, the European Institute for Nuclear Research.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/spinlock.h>
#include <linux/fmc.h>
#include <linux/uaccess.h>
static LIST_HEAD(fc_devices);
static DEFINE_SPINLOCK(fc_lock);
struct fc_instance {
struct list_head list;
struct fmc_device *fmc;
struct miscdevice misc;
};
/* at open time, we must identify our device */
static int fc_open(struct inode *ino, struct file *f)
{
struct fmc_device *fmc;
struct fc_instance *fc;
int minor = iminor(ino);
list_for_each_entry(fc, &fc_devices, list)
if (fc->misc.minor == minor)
break;
if (fc->misc.minor != minor)
return -ENODEV;
fmc = fc->fmc;
if (try_module_get(fmc->owner) == 0)
return -ENODEV;
f->private_data = fmc;
return 0;
}
static int fc_release(struct inode *ino, struct file *f)
{
struct fmc_device *fmc = f->private_data;
module_put(fmc->owner);
return 0;
}
/* read and write are simple after the default llseek has been used */
static ssize_t fc_read(struct file *f, char __user *buf, size_t count,
loff_t *offp)
{
struct fmc_device *fmc = f->private_data;
unsigned long addr;
uint32_t val;
if (count < sizeof(val))
return -EINVAL;
count = sizeof(val);
addr = *offp;
if (addr > fmc->memlen)
return -ESPIPE; /* Illegal seek */
val = fmc_readl(fmc, addr);
if (copy_to_user(buf, &val, count))
return -EFAULT;
*offp += count;
return count;
}
static ssize_t fc_write(struct file *f, const char __user *buf, size_t count,
loff_t *offp)
{
struct fmc_device *fmc = f->private_data;
unsigned long addr;
uint32_t val;
if (count < sizeof(val))
return -EINVAL;
count = sizeof(val);
addr = *offp;
if (addr > fmc->memlen)
return -ESPIPE; /* Illegal seek */
if (copy_from_user(&val, buf, count))
return -EFAULT;
fmc_writel(fmc, val, addr);
*offp += count;
return count;
}
static const struct file_operations fc_fops = {
.owner = THIS_MODULE,
.open = fc_open,
.release = fc_release,
.llseek = generic_file_llseek,
.read = fc_read,
.write = fc_write,
};
/* Device part .. */
static int fc_probe(struct fmc_device *fmc);
static int fc_remove(struct fmc_device *fmc);
static struct fmc_driver fc_drv = {
.version = FMC_VERSION,
.driver.name = KBUILD_MODNAME,
.probe = fc_probe,
.remove = fc_remove,
/* no table: we want to match everything */
};
/* We accept the generic busid parameter */
FMC_PARAM_BUSID(fc_drv);
/* probe and remove must allocate and release a misc device */
static int fc_probe(struct fmc_device *fmc)
{
int ret;
int index = 0;
struct fc_instance *fc;
if (fmc->op->validate)
index = fmc->op->validate(fmc, &fc_drv);
if (index < 0)
return -EINVAL; /* not our device: invalid */
/* Create a char device: we want to create it anew */
fc = kzalloc(sizeof(*fc), GFP_KERNEL);
fc->fmc = fmc;
fc->misc.minor = MISC_DYNAMIC_MINOR;
fc->misc.fops = &fc_fops;
fc->misc.name = kstrdup(dev_name(&fmc->dev), GFP_KERNEL);
spin_lock(&fc_lock);
ret = misc_register(&fc->misc);
if (ret < 0) {
kfree(fc->misc.name);
kfree(fc);
} else {
list_add(&fc->list, &fc_devices);
}
spin_unlock(&fc_lock);
dev_info(&fc->fmc->dev, "Created misc device \"%s\"\n",
fc->misc.name);
return ret;
}
static int fc_remove(struct fmc_device *fmc)
{
struct fc_instance *fc;
list_for_each_entry(fc, &fc_devices, list)
if (fc->fmc == fmc)
break;
if (fc->fmc != fmc) {
dev_err(&fmc->dev, "remove called but not found\n");
return -ENODEV;
}
spin_lock(&fc_lock);
list_del(&fc->list);
misc_deregister(&fc->misc);
kfree(fc->misc.name);
kfree(fc);
spin_unlock(&fc_lock);
return 0;
}
static int fc_init(void)
{
int ret;
ret = fmc_driver_register(&fc_drv);
return ret;
}
static void fc_exit(void)
{
fmc_driver_unregister(&fc_drv);
}
module_init(fc_init);
module_exit(fc_exit);
MODULE_LICENSE("GPL");
|
