This source file includes following definitions.
- flash_mmap
- flash_llseek
- flash_read
- flash_open
- flash_release
- flash_probe
- flash_remove
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7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/errno.h>
10 #include <linux/miscdevice.h>
11 #include <linux/fcntl.h>
12 #include <linux/poll.h>
13 #include <linux/mutex.h>
14 #include <linux/spinlock.h>
15 #include <linux/mm.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18
19 #include <linux/uaccess.h>
20 #include <asm/pgtable.h>
21 #include <asm/io.h>
22 #include <asm/upa.h>
23
24 static DEFINE_MUTEX(flash_mutex);
25 static DEFINE_SPINLOCK(flash_lock);
26 static struct {
27 unsigned long read_base;
28 unsigned long write_base;
29 unsigned long read_size;
30 unsigned long write_size;
31 unsigned long busy;
32 } flash;
33
34 #define FLASH_MINOR 152
35
36 static int
37 flash_mmap(struct file *file, struct vm_area_struct *vma)
38 {
39 unsigned long addr;
40 unsigned long size;
41
42 spin_lock(&flash_lock);
43 if (flash.read_base == flash.write_base) {
44 addr = flash.read_base;
45 size = flash.read_size;
46 } else {
47 if ((vma->vm_flags & VM_READ) &&
48 (vma->vm_flags & VM_WRITE)) {
49 spin_unlock(&flash_lock);
50 return -EINVAL;
51 }
52 if (vma->vm_flags & VM_READ) {
53 addr = flash.read_base;
54 size = flash.read_size;
55 } else if (vma->vm_flags & VM_WRITE) {
56 addr = flash.write_base;
57 size = flash.write_size;
58 } else {
59 spin_unlock(&flash_lock);
60 return -ENXIO;
61 }
62 }
63 spin_unlock(&flash_lock);
64
65 if ((vma->vm_pgoff << PAGE_SHIFT) > size)
66 return -ENXIO;
67 addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
68
69 if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
70 size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
71
72 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
73
74 if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
75 return -EAGAIN;
76
77 return 0;
78 }
79
80 static long long
81 flash_llseek(struct file *file, long long offset, int origin)
82 {
83 mutex_lock(&flash_mutex);
84 switch (origin) {
85 case 0:
86 file->f_pos = offset;
87 break;
88 case 1:
89 file->f_pos += offset;
90 if (file->f_pos > flash.read_size)
91 file->f_pos = flash.read_size;
92 break;
93 case 2:
94 file->f_pos = flash.read_size;
95 break;
96 default:
97 mutex_unlock(&flash_mutex);
98 return -EINVAL;
99 }
100 mutex_unlock(&flash_mutex);
101 return file->f_pos;
102 }
103
104 static ssize_t
105 flash_read(struct file * file, char __user * buf,
106 size_t count, loff_t *ppos)
107 {
108 loff_t p = *ppos;
109 int i;
110
111 if (count > flash.read_size - p)
112 count = flash.read_size - p;
113
114 for (i = 0; i < count; i++) {
115 u8 data = upa_readb(flash.read_base + p + i);
116 if (put_user(data, buf))
117 return -EFAULT;
118 buf++;
119 }
120
121 *ppos += count;
122 return count;
123 }
124
125 static int
126 flash_open(struct inode *inode, struct file *file)
127 {
128 mutex_lock(&flash_mutex);
129 if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
130 mutex_unlock(&flash_mutex);
131 return -EBUSY;
132 }
133
134 mutex_unlock(&flash_mutex);
135 return 0;
136 }
137
138 static int
139 flash_release(struct inode *inode, struct file *file)
140 {
141 spin_lock(&flash_lock);
142 flash.busy = 0;
143 spin_unlock(&flash_lock);
144
145 return 0;
146 }
147
148 static const struct file_operations flash_fops = {
149
150
151
152 .owner = THIS_MODULE,
153 .llseek = flash_llseek,
154 .read = flash_read,
155 .mmap = flash_mmap,
156 .open = flash_open,
157 .release = flash_release,
158 };
159
160 static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
161
162 static int flash_probe(struct platform_device *op)
163 {
164 struct device_node *dp = op->dev.of_node;
165 struct device_node *parent;
166
167 parent = dp->parent;
168
169 if (!of_node_name_eq(parent, "sbus") &&
170 !of_node_name_eq(parent, "sbi") &&
171 !of_node_name_eq(parent, "ebus"))
172 return -ENODEV;
173
174 flash.read_base = op->resource[0].start;
175 flash.read_size = resource_size(&op->resource[0]);
176 if (op->resource[1].flags) {
177 flash.write_base = op->resource[1].start;
178 flash.write_size = resource_size(&op->resource[1]);
179 } else {
180 flash.write_base = op->resource[0].start;
181 flash.write_size = resource_size(&op->resource[0]);
182 }
183 flash.busy = 0;
184
185 printk(KERN_INFO "%pOF: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
186 op->dev.of_node,
187 flash.read_base, flash.read_size,
188 flash.write_base, flash.write_size);
189
190 return misc_register(&flash_dev);
191 }
192
193 static int flash_remove(struct platform_device *op)
194 {
195 misc_deregister(&flash_dev);
196
197 return 0;
198 }
199
200 static const struct of_device_id flash_match[] = {
201 {
202 .name = "flashprom",
203 },
204 {},
205 };
206 MODULE_DEVICE_TABLE(of, flash_match);
207
208 static struct platform_driver flash_driver = {
209 .driver = {
210 .name = "flash",
211 .of_match_table = flash_match,
212 },
213 .probe = flash_probe,
214 .remove = flash_remove,
215 };
216
217 module_platform_driver(flash_driver);
218
219 MODULE_LICENSE("GPL");