Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / drivers / sbus / char / flash.c
1 /* $Id: flash.c,v 1.25 2001/12/21 04:56:16 davem Exp $
2  * flash.c: Allow mmap access to the OBP Flash, for OBP updates.
3  *
4  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
5  */
6
7 #include <linux/config.h>
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/miscdevice.h>
12 #include <linux/slab.h>
13 #include <linux/fcntl.h>
14 #include <linux/poll.h>
15 #include <linux/init.h>
16 #include <linux/smp_lock.h>
17 #include <linux/spinlock.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/sbus.h>
24 #include <asm/ebus.h>
25 #include <asm/upa.h>
26
27 static DEFINE_SPINLOCK(flash_lock);
28 static struct {
29         unsigned long read_base;        /* Physical read address */
30         unsigned long write_base;       /* Physical write address */
31         unsigned long read_size;        /* Size of read area */
32         unsigned long write_size;       /* Size of write area */
33         unsigned long busy;             /* In use? */
34 } flash;
35
36 #define FLASH_MINOR     152
37
38 static int
39 flash_mmap(struct file *file, struct vm_area_struct *vma)
40 {
41         unsigned long addr;
42         unsigned long size;
43
44         spin_lock(&flash_lock);
45         if (flash.read_base == flash.write_base) {
46                 addr = flash.read_base;
47                 size = flash.read_size;
48         } else {
49                 if ((vma->vm_flags & VM_READ) &&
50                     (vma->vm_flags & VM_WRITE)) {
51                         spin_unlock(&flash_lock);
52                         return -EINVAL;
53                 }
54                 if (vma->vm_flags & VM_READ) {
55                         addr = flash.read_base;
56                         size = flash.read_size;
57                 } else if (vma->vm_flags & VM_WRITE) {
58                         addr = flash.write_base;
59                         size = flash.write_size;
60                 } else {
61                         spin_unlock(&flash_lock);
62                         return -ENXIO;
63                 }
64         }
65         spin_unlock(&flash_lock);
66
67         if ((vma->vm_pgoff << PAGE_SHIFT) > size)
68                 return -ENXIO;
69         addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
70
71         if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
72                 size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
73
74         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
75
76         if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
77                 return -EAGAIN;
78                 
79         return 0;
80 }
81
82 static long long
83 flash_llseek(struct file *file, long long offset, int origin)
84 {
85         lock_kernel();
86         switch (origin) {
87                 case 0:
88                         file->f_pos = offset;
89                         break;
90                 case 1:
91                         file->f_pos += offset;
92                         if (file->f_pos > flash.read_size)
93                                 file->f_pos = flash.read_size;
94                         break;
95                 case 2:
96                         file->f_pos = flash.read_size;
97                         break;
98                 default:
99                         unlock_kernel();
100                         return -EINVAL;
101         }
102         unlock_kernel();
103         return file->f_pos;
104 }
105
106 static ssize_t
107 flash_read(struct file * file, char __user * buf,
108            size_t count, loff_t *ppos)
109 {
110         unsigned long p = file->f_pos;
111         int i;
112         
113         if (count > flash.read_size - p)
114                 count = flash.read_size - p;
115
116         for (i = 0; i < count; i++) {
117                 u8 data = upa_readb(flash.read_base + p + i);
118                 if (put_user(data, buf))
119                         return -EFAULT;
120                 buf++;
121         }
122
123         file->f_pos += count;
124         return count;
125 }
126
127 static int
128 flash_open(struct inode *inode, struct file *file)
129 {
130         if (test_and_set_bit(0, (void *)&flash.busy) != 0)
131                 return -EBUSY;
132
133         return 0;
134 }
135
136 static int
137 flash_release(struct inode *inode, struct file *file)
138 {
139         spin_lock(&flash_lock);
140         flash.busy = 0;
141         spin_unlock(&flash_lock);
142
143         return 0;
144 }
145
146 static struct file_operations flash_fops = {
147         /* no write to the Flash, use mmap
148          * and play flash dependent tricks.
149          */
150         .owner =        THIS_MODULE,
151         .llseek =       flash_llseek,
152         .read =         flash_read,
153         .mmap =         flash_mmap,
154         .open =         flash_open,
155         .release =      flash_release,
156 };
157
158 static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
159
160 static int __init flash_init(void)
161 {
162         struct sbus_bus *sbus;
163         struct sbus_dev *sdev = NULL;
164 #ifdef CONFIG_PCI
165         struct linux_ebus *ebus;
166         struct linux_ebus_device *edev = NULL;
167         struct linux_prom_registers regs[2];
168         int len, nregs;
169 #endif
170         int err;
171
172         for_all_sbusdev(sdev, sbus) {
173                 if (!strcmp(sdev->prom_name, "flashprom")) {
174                         if (sdev->reg_addrs[0].phys_addr == sdev->reg_addrs[1].phys_addr) {
175                                 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
176                                         (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
177                                 flash.read_size = sdev->reg_addrs[0].reg_size;
178                                 flash.write_base = flash.read_base;
179                                 flash.write_size = flash.read_size;
180                         } else {
181                                 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
182                                         (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
183                                 flash.read_size = sdev->reg_addrs[0].reg_size;
184                                 flash.write_base = ((unsigned long)sdev->reg_addrs[1].phys_addr) |
185                                         (((unsigned long)sdev->reg_addrs[1].which_io)<<32UL);
186                                 flash.write_size = sdev->reg_addrs[1].reg_size;
187                         }
188                         flash.busy = 0;
189                         break;
190                 }
191         }
192         if (!sdev) {
193 #ifdef CONFIG_PCI
194                 struct linux_prom_registers *ebus_regs;
195
196                 for_each_ebus(ebus) {
197                         for_each_ebusdev(edev, ebus) {
198                                 if (!strcmp(edev->prom_node->name, "flashprom"))
199                                         goto ebus_done;
200                         }
201                 }
202         ebus_done:
203                 if (!edev)
204                         return -ENODEV;
205
206                 ebus_regs = of_get_property(edev->prom_node, "reg", &len);
207                 if (!ebus_regs || (len % sizeof(regs[0])) != 0) {
208                         printk("flash: Strange reg property size %d\n", len);
209                         return -ENODEV;
210                 }
211
212                 nregs = len / sizeof(ebus_regs[0]);
213
214                 flash.read_base = edev->resource[0].start;
215                 flash.read_size = ebus_regs[0].reg_size;
216
217                 if (nregs == 1) {
218                         flash.write_base = edev->resource[0].start;
219                         flash.write_size = ebus_regs[0].reg_size;
220                 } else if (nregs == 2) {
221                         flash.write_base = edev->resource[1].start;
222                         flash.write_size = ebus_regs[1].reg_size;
223                 } else {
224                         printk("flash: Strange number of regs %d\n", nregs);
225                         return -ENODEV;
226                 }
227
228                 flash.busy = 0;
229
230 #else
231                 return -ENODEV;
232 #endif
233         }
234
235         printk("OBP Flash: RD %lx[%lx] WR %lx[%lx]\n",
236                flash.read_base, flash.read_size,
237                flash.write_base, flash.write_size);
238
239         err = misc_register(&flash_dev);
240         if (err) {
241                 printk(KERN_ERR "flash: unable to get misc minor\n");
242                 return err;
243         }
244
245         return 0;
246 }
247
248 static void __exit flash_cleanup(void)
249 {
250         misc_deregister(&flash_dev);
251 }
252
253 module_init(flash_init);
254 module_exit(flash_cleanup);
255 MODULE_LICENSE("GPL");