Merge branch 'intelfb-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...
[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/module.h>
8 #include <linux/types.h>
9 #include <linux/errno.h>
10 #include <linux/miscdevice.h>
11 #include <linux/slab.h>
12 #include <linux/fcntl.h>
13 #include <linux/poll.h>
14 #include <linux/init.h>
15 #include <linux/smp_lock.h>
16 #include <linux/spinlock.h>
17
18 #include <asm/system.h>
19 #include <asm/uaccess.h>
20 #include <asm/pgtable.h>
21 #include <asm/io.h>
22 #include <asm/sbus.h>
23 #include <asm/ebus.h>
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
73         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
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 {
129         if (test_and_set_bit(0, (void *)&flash.busy) != 0)
130                 return -EBUSY;
131
132         return 0;
133 }
134
135 static int
136 flash_release(struct inode *inode, struct file *file)
137 {
138         spin_lock(&flash_lock);
139         flash.busy = 0;
140         spin_unlock(&flash_lock);
141
142         return 0;
143 }
144
145 static struct file_operations flash_fops = {
146         /* no write to the Flash, use mmap
147          * and play flash dependent tricks.
148          */
149         .owner =        THIS_MODULE,
150         .llseek =       flash_llseek,
151         .read =         flash_read,
152         .mmap =         flash_mmap,
153         .open =         flash_open,
154         .release =      flash_release,
155 };
156
157 static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
158
159 static int __init flash_init(void)
160 {
161         struct sbus_bus *sbus;
162         struct sbus_dev *sdev = NULL;
163 #ifdef CONFIG_PCI
164         struct linux_ebus *ebus;
165         struct linux_ebus_device *edev = NULL;
166         struct linux_prom_registers regs[2];
167         int len, nregs;
168 #endif
169         int err;
170
171         for_all_sbusdev(sdev, sbus) {
172                 if (!strcmp(sdev->prom_name, "flashprom")) {
173                         if (sdev->reg_addrs[0].phys_addr == sdev->reg_addrs[1].phys_addr) {
174                                 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
175                                         (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
176                                 flash.read_size = sdev->reg_addrs[0].reg_size;
177                                 flash.write_base = flash.read_base;
178                                 flash.write_size = flash.read_size;
179                         } else {
180                                 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
181                                         (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
182                                 flash.read_size = sdev->reg_addrs[0].reg_size;
183                                 flash.write_base = ((unsigned long)sdev->reg_addrs[1].phys_addr) |
184                                         (((unsigned long)sdev->reg_addrs[1].which_io)<<32UL);
185                                 flash.write_size = sdev->reg_addrs[1].reg_size;
186                         }
187                         flash.busy = 0;
188                         break;
189                 }
190         }
191         if (!sdev) {
192 #ifdef CONFIG_PCI
193                 struct linux_prom_registers *ebus_regs;
194
195                 for_each_ebus(ebus) {
196                         for_each_ebusdev(edev, ebus) {
197                                 if (!strcmp(edev->prom_node->name, "flashprom"))
198                                         goto ebus_done;
199                         }
200                 }
201         ebus_done:
202                 if (!edev)
203                         return -ENODEV;
204
205                 ebus_regs = of_get_property(edev->prom_node, "reg", &len);
206                 if (!ebus_regs || (len % sizeof(regs[0])) != 0) {
207                         printk("flash: Strange reg property size %d\n", len);
208                         return -ENODEV;
209                 }
210
211                 nregs = len / sizeof(ebus_regs[0]);
212
213                 flash.read_base = edev->resource[0].start;
214                 flash.read_size = ebus_regs[0].reg_size;
215
216                 if (nregs == 1) {
217                         flash.write_base = edev->resource[0].start;
218                         flash.write_size = ebus_regs[0].reg_size;
219                 } else if (nregs == 2) {
220                         flash.write_base = edev->resource[1].start;
221                         flash.write_size = ebus_regs[1].reg_size;
222                 } else {
223                         printk("flash: Strange number of regs %d\n", nregs);
224                         return -ENODEV;
225                 }
226
227                 flash.busy = 0;
228
229 #else
230                 return -ENODEV;
231 #endif
232         }
233
234         printk("OBP Flash: RD %lx[%lx] WR %lx[%lx]\n",
235                flash.read_base, flash.read_size,
236                flash.write_base, flash.write_size);
237
238         err = misc_register(&flash_dev);
239         if (err) {
240                 printk(KERN_ERR "flash: unable to get misc minor\n");
241                 return err;
242         }
243
244         return 0;
245 }
246
247 static void __exit flash_cleanup(void)
248 {
249         misc_deregister(&flash_dev);
250 }
251
252 module_init(flash_init);
253 module_exit(flash_cleanup);
254 MODULE_LICENSE("GPL");