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
229
|
/* flash.c: Allow mmap access to the OBP Flash, for OBP updates.
*
* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/upa.h>
static DEFINE_SPINLOCK(flash_lock);
static struct {
unsigned long read_base; /* Physical read address */
unsigned long write_base; /* Physical write address */
unsigned long read_size; /* Size of read area */
unsigned long write_size; /* Size of write area */
unsigned long busy; /* In use? */
} flash;
#define FLASH_MINOR 152
static int
flash_mmap(struct file *file, struct vm_area_struct *vma)
{
unsigned long addr;
unsigned long size;
spin_lock(&flash_lock);
if (flash.read_base == flash.write_base) {
addr = flash.read_base;
size = flash.read_size;
} else {
if ((vma->vm_flags & VM_READ) &&
(vma->vm_flags & VM_WRITE)) {
spin_unlock(&flash_lock);
return -EINVAL;
}
if (vma->vm_flags & VM_READ) {
addr = flash.read_base;
size = flash.read_size;
} else if (vma->vm_flags & VM_WRITE) {
addr = flash.write_base;
size = flash.write_size;
} else {
spin_unlock(&flash_lock);
return -ENXIO;
}
}
spin_unlock(&flash_lock);
if ((vma->vm_pgoff << PAGE_SHIFT) > size)
return -ENXIO;
addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
return -EAGAIN;
return 0;
}
static long long
flash_llseek(struct file *file, long long offset, int origin)
{
lock_kernel();
switch (origin) {
case 0:
file->f_pos = offset;
break;
case 1:
file->f_pos += offset;
if (file->f_pos > flash.read_size)
file->f_pos = flash.read_size;
break;
case 2:
file->f_pos = flash.read_size;
break;
default:
unlock_kernel();
return -EINVAL;
}
unlock_kernel();
return file->f_pos;
}
static ssize_t
flash_read(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
unsigned long p = file->f_pos;
int i;
if (count > flash.read_size - p)
count = flash.read_size - p;
for (i = 0; i < count; i++) {
u8 data = upa_readb(flash.read_base + p + i);
if (put_user(data, buf))
return -EFAULT;
buf++;
}
file->f_pos += count;
return count;
}
static int
flash_open(struct inode *inode, struct file *file)
{
lock_kernel();
if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
unlock_kernel();
return -EBUSY;
}
unlock_kernel();
return 0;
}
static int
flash_release(struct inode *inode, struct file *file)
{
spin_lock(&flash_lock);
flash.busy = 0;
spin_unlock(&flash_lock);
return 0;
}
static const struct file_operations flash_fops = {
/* no write to the Flash, use mmap
* and play flash dependent tricks.
*/
.owner = THIS_MODULE,
.llseek = flash_llseek,
.read = flash_read,
.mmap = flash_mmap,
.open = flash_open,
.release = flash_release,
};
static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
static int __devinit flash_probe(struct of_device *op,
const struct of_device_id *match)
{
struct device_node *dp = op->node;
struct device_node *parent;
parent = dp->parent;
if (strcmp(parent->name, "sbus") &&
strcmp(parent->name, "sbi") &&
strcmp(parent->name, "ebus"))
return -ENODEV;
flash.read_base = op->resource[0].start;
flash.read_size = resource_size(&op->resource[0]);
if (op->resource[1].flags) {
flash.write_base = op->resource[1].start;
flash.write_size = resource_size(&op->resource[1]);
} else {
flash.write_base = op->resource[0].start;
flash.write_size = resource_size(&op->resource[0]);
}
flash.busy = 0;
printk(KERN_INFO "%s: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
op->node->full_name,
flash.read_base, flash.read_size,
flash.write_base, flash.write_size);
return misc_register(&flash_dev);
}
static int __devexit flash_remove(struct of_device *op)
{
misc_deregister(&flash_dev);
return 0;
}
static struct of_device_id flash_match[] = {
{
.name = "flashprom",
},
{},
};
MODULE_DEVICE_TABLE(of, flash_match);
static struct of_platform_driver flash_driver = {
.name = "flash",
.match_table = flash_match,
.probe = flash_probe,
.remove = __devexit_p(flash_remove),
};
static int __init flash_init(void)
{
return of_register_driver(&flash_driver, &of_bus_type);
}
static void __exit flash_cleanup(void)
{
of_unregister_driver(&flash_driver);
}
module_init(flash_init);
module_exit(flash_cleanup);
MODULE_LICENSE("GPL");
|
