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6#include <linux/module.h>
7#include <linux/types.h>
8#include <linux/errno.h>
9#include <linux/miscdevice.h>
10#include <linux/fcntl.h>
11#include <linux/poll.h>
12#include <linux/init.h>
13#include <linux/smp_lock.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 <asm/system.h>
20#include <asm/uaccess.h>
21#include <asm/pgtable.h>
22#include <asm/io.h>
23#include <asm/upa.h>
24
25static DEFINE_SPINLOCK(flash_lock);
26static 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
36static int
37flash_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
80static long long
81flash_llseek(struct file *file, long long offset, int origin)
82{
83 lock_kernel();
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 unlock_kernel();
98 return -EINVAL;
99 }
100 unlock_kernel();
101 return file->f_pos;
102}
103
104static ssize_t
105flash_read(struct file * file, char __user * buf,
106 size_t count, loff_t *ppos)
107{
108 unsigned long p = file->f_pos;
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 file->f_pos += count;
122 return count;
123}
124
125static int
126flash_open(struct inode *inode, struct file *file)
127{
128 lock_kernel();
129 if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
130 unlock_kernel();
131 return -EBUSY;
132 }
133
134 unlock_kernel();
135 return 0;
136}
137
138static int
139flash_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
148static 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
160static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
161
162static int __devinit flash_probe(struct of_device *op,
163 const struct of_device_id *match)
164{
165 struct device_node *dp = op->node;
166 struct device_node *parent;
167
168 parent = dp->parent;
169
170 if (strcmp(parent->name, "sbus") &&
171 strcmp(parent->name, "sbi") &&
172 strcmp(parent->name, "ebus"))
173 return -ENODEV;
174
175 flash.read_base = op->resource[0].start;
176 flash.read_size = resource_size(&op->resource[0]);
177 if (op->resource[1].flags) {
178 flash.write_base = op->resource[1].start;
179 flash.write_size = resource_size(&op->resource[1]);
180 } else {
181 flash.write_base = op->resource[0].start;
182 flash.write_size = resource_size(&op->resource[0]);
183 }
184 flash.busy = 0;
185
186 printk(KERN_INFO "%s: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
187 op->node->full_name,
188 flash.read_base, flash.read_size,
189 flash.write_base, flash.write_size);
190
191 return misc_register(&flash_dev);
192}
193
194static int __devexit flash_remove(struct of_device *op)
195{
196 misc_deregister(&flash_dev);
197
198 return 0;
199}
200
201static const struct of_device_id flash_match[] = {
202 {
203 .name = "flashprom",
204 },
205 {},
206};
207MODULE_DEVICE_TABLE(of, flash_match);
208
209static struct of_platform_driver flash_driver = {
210 .name = "flash",
211 .match_table = flash_match,
212 .probe = flash_probe,
213 .remove = __devexit_p(flash_remove),
214};
215
216static int __init flash_init(void)
217{
218 return of_register_driver(&flash_driver, &of_bus_type);
219}
220
221static void __exit flash_cleanup(void)
222{
223 of_unregister_driver(&flash_driver);
224}
225
226module_init(flash_init);
227module_exit(flash_cleanup);
228MODULE_LICENSE("GPL");
229
