Commit | Line | Data |
---|---|---|
a9540d34 | 1 | /* flash.c: Allow mmap access to the OBP Flash, for OBP updates. |
1da177e4 LT |
2 | * |
3 | * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be) | |
4 | */ | |
5 | ||
1da177e4 LT |
6 | #include <linux/module.h> |
7 | #include <linux/types.h> | |
8 | #include <linux/errno.h> | |
9 | #include <linux/miscdevice.h> | |
10 | #include <linux/slab.h> | |
11 | #include <linux/fcntl.h> | |
12 | #include <linux/poll.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/smp_lock.h> | |
15 | #include <linux/spinlock.h> | |
8a73709e | 16 | #include <linux/mm.h> |
a9540d34 DM |
17 | #include <linux/of.h> |
18 | #include <linux/of_device.h> | |
1da177e4 LT |
19 | |
20 | #include <asm/system.h> | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/pgtable.h> | |
23 | #include <asm/io.h> | |
1da177e4 LT |
24 | #include <asm/upa.h> |
25 | ||
26 | static DEFINE_SPINLOCK(flash_lock); | |
27 | static struct { | |
28 | unsigned long read_base; /* Physical read address */ | |
29 | unsigned long write_base; /* Physical write address */ | |
30 | unsigned long read_size; /* Size of read area */ | |
31 | unsigned long write_size; /* Size of write area */ | |
32 | unsigned long busy; /* In use? */ | |
33 | } flash; | |
34 | ||
35 | #define FLASH_MINOR 152 | |
36 | ||
37 | static int | |
38 | flash_mmap(struct file *file, struct vm_area_struct *vma) | |
39 | { | |
40 | unsigned long addr; | |
41 | unsigned long size; | |
42 | ||
43 | spin_lock(&flash_lock); | |
44 | if (flash.read_base == flash.write_base) { | |
45 | addr = flash.read_base; | |
46 | size = flash.read_size; | |
47 | } else { | |
48 | if ((vma->vm_flags & VM_READ) && | |
49 | (vma->vm_flags & VM_WRITE)) { | |
50 | spin_unlock(&flash_lock); | |
51 | return -EINVAL; | |
52 | } | |
53 | if (vma->vm_flags & VM_READ) { | |
54 | addr = flash.read_base; | |
55 | size = flash.read_size; | |
56 | } else if (vma->vm_flags & VM_WRITE) { | |
57 | addr = flash.write_base; | |
58 | size = flash.write_size; | |
59 | } else { | |
60 | spin_unlock(&flash_lock); | |
61 | return -ENXIO; | |
62 | } | |
63 | } | |
64 | spin_unlock(&flash_lock); | |
65 | ||
66 | if ((vma->vm_pgoff << PAGE_SHIFT) > size) | |
67 | return -ENXIO; | |
68 | addr = vma->vm_pgoff + (addr >> PAGE_SHIFT); | |
69 | ||
70 | if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size) | |
71 | size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)); | |
72 | ||
14778d90 | 73 | vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); |
1da177e4 LT |
74 | |
75 | if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot)) | |
76 | return -EAGAIN; | |
77 | ||
78 | return 0; | |
79 | } | |
80 | ||
81 | static long long | |
82 | flash_llseek(struct file *file, long long offset, int origin) | |
83 | { | |
84 | lock_kernel(); | |
85 | switch (origin) { | |
86 | case 0: | |
87 | file->f_pos = offset; | |
88 | break; | |
89 | case 1: | |
90 | file->f_pos += offset; | |
91 | if (file->f_pos > flash.read_size) | |
92 | file->f_pos = flash.read_size; | |
93 | break; | |
94 | case 2: | |
95 | file->f_pos = flash.read_size; | |
96 | break; | |
97 | default: | |
98 | unlock_kernel(); | |
99 | return -EINVAL; | |
100 | } | |
101 | unlock_kernel(); | |
102 | return file->f_pos; | |
103 | } | |
104 | ||
105 | static ssize_t | |
106 | flash_read(struct file * file, char __user * buf, | |
107 | size_t count, loff_t *ppos) | |
108 | { | |
109 | unsigned long p = file->f_pos; | |
110 | int i; | |
111 | ||
112 | if (count > flash.read_size - p) | |
113 | count = flash.read_size - p; | |
114 | ||
115 | for (i = 0; i < count; i++) { | |
116 | u8 data = upa_readb(flash.read_base + p + i); | |
117 | if (put_user(data, buf)) | |
118 | return -EFAULT; | |
119 | buf++; | |
120 | } | |
121 | ||
122 | file->f_pos += count; | |
123 | return count; | |
124 | } | |
125 | ||
126 | static int | |
127 | flash_open(struct inode *inode, struct file *file) | |
128 | { | |
78abb6ac AB |
129 | lock_kernel(); |
130 | if (test_and_set_bit(0, (void *)&flash.busy) != 0) { | |
131 | unlock_kernel(); | |
1da177e4 | 132 | return -EBUSY; |
78abb6ac | 133 | } |
1da177e4 | 134 | |
78abb6ac | 135 | unlock_kernel(); |
1da177e4 LT |
136 | return 0; |
137 | } | |
138 | ||
139 | static int | |
140 | flash_release(struct inode *inode, struct file *file) | |
141 | { | |
142 | spin_lock(&flash_lock); | |
143 | flash.busy = 0; | |
144 | spin_unlock(&flash_lock); | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
00977a59 | 149 | static const struct file_operations flash_fops = { |
1da177e4 LT |
150 | /* no write to the Flash, use mmap |
151 | * and play flash dependent tricks. | |
152 | */ | |
153 | .owner = THIS_MODULE, | |
154 | .llseek = flash_llseek, | |
155 | .read = flash_read, | |
156 | .mmap = flash_mmap, | |
157 | .open = flash_open, | |
158 | .release = flash_release, | |
159 | }; | |
160 | ||
161 | static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops }; | |
162 | ||
a9540d34 DM |
163 | static int __devinit flash_probe(struct of_device *op, |
164 | const struct of_device_id *match) | |
1da177e4 | 165 | { |
a9540d34 DM |
166 | struct device_node *dp = op->node; |
167 | struct device_node *parent; | |
1da177e4 | 168 | |
a9540d34 | 169 | parent = dp->parent; |
1da177e4 | 170 | |
a9540d34 DM |
171 | if (strcmp(parent->name, "sbus") && |
172 | strcmp(parent->name, "sbi") && | |
173 | strcmp(parent->name, "ebus")) | |
1da177e4 | 174 | return -ENODEV; |
a9540d34 DM |
175 | |
176 | flash.read_base = op->resource[0].start; | |
177 | flash.read_size = resource_size(&op->resource[0]); | |
178 | if (op->resource[1].flags) { | |
179 | flash.write_base = op->resource[1].start; | |
180 | flash.write_size = resource_size(&op->resource[1]); | |
181 | } else { | |
182 | flash.write_base = op->resource[0].start; | |
183 | flash.write_size = resource_size(&op->resource[0]); | |
1da177e4 | 184 | } |
a9540d34 | 185 | flash.busy = 0; |
1da177e4 | 186 | |
a9540d34 DM |
187 | printk(KERN_INFO "%s: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n", |
188 | op->node->full_name, | |
1da177e4 LT |
189 | flash.read_base, flash.read_size, |
190 | flash.write_base, flash.write_size); | |
191 | ||
a9540d34 DM |
192 | return misc_register(&flash_dev); |
193 | } | |
194 | ||
195 | static int __devexit flash_remove(struct of_device *op) | |
196 | { | |
197 | misc_deregister(&flash_dev); | |
1da177e4 LT |
198 | |
199 | return 0; | |
200 | } | |
201 | ||
fd098316 | 202 | static const struct of_device_id flash_match[] = { |
a9540d34 DM |
203 | { |
204 | .name = "flashprom", | |
205 | }, | |
206 | {}, | |
207 | }; | |
208 | MODULE_DEVICE_TABLE(of, flash_match); | |
209 | ||
210 | static struct of_platform_driver flash_driver = { | |
211 | .name = "flash", | |
212 | .match_table = flash_match, | |
213 | .probe = flash_probe, | |
214 | .remove = __devexit_p(flash_remove), | |
215 | }; | |
216 | ||
217 | static int __init flash_init(void) | |
218 | { | |
219 | return of_register_driver(&flash_driver, &of_bus_type); | |
220 | } | |
221 | ||
1da177e4 LT |
222 | static void __exit flash_cleanup(void) |
223 | { | |
a9540d34 | 224 | of_unregister_driver(&flash_driver); |
1da177e4 LT |
225 | } |
226 | ||
227 | module_init(flash_init); | |
228 | module_exit(flash_cleanup); | |
229 | MODULE_LICENSE("GPL"); |