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.
4 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
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>
19 #include <asm/system.h>
20 #include <asm/uaccess.h>
21 #include <asm/pgtable.h>
26 static spinlock_t flash_lock = SPIN_LOCK_UNLOCKED;
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? */
35 #define FLASH_MINOR 152
38 flash_mmap(struct file *file, struct vm_area_struct *vma)
43 spin_lock(&flash_lock);
44 if (flash.read_base == flash.write_base) {
45 addr = flash.read_base;
46 size = flash.read_size;
48 if ((vma->vm_flags & VM_READ) &&
49 (vma->vm_flags & VM_WRITE)) {
50 spin_unlock(&flash_lock);
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;
60 spin_unlock(&flash_lock);
64 spin_unlock(&flash_lock);
66 if ((vma->vm_pgoff << PAGE_SHIFT) > size)
68 addr += (vma->vm_pgoff << PAGE_SHIFT);
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));
73 pgprot_val(vma->vm_page_prot) &= ~(_PAGE_CACHE);
74 pgprot_val(vma->vm_page_prot) |= _PAGE_E;
75 vma->vm_flags |= (VM_SHM | VM_LOCKED);
77 if (remap_page_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
84 flash_llseek(struct file *file, long long offset, int origin)
92 file->f_pos += offset;
93 if (file->f_pos > flash.read_size)
94 file->f_pos = flash.read_size;
97 file->f_pos = flash.read_size;
108 flash_read(struct file * file, char * buf,
109 size_t count, loff_t *ppos)
111 unsigned long p = file->f_pos;
114 if (count > flash.read_size - p)
115 count = flash.read_size - p;
117 for (i = 0; i < count; i++) {
118 u8 data = readb(flash.read_base + p + i);
119 if (put_user(data, buf))
124 file->f_pos += count;
129 flash_open(struct inode *inode, struct file *file)
131 if (test_and_set_bit(0, (void *)&flash.busy) != 0)
138 flash_release(struct inode *inode, struct file *file)
140 spin_lock(&flash_lock);
142 spin_unlock(&flash_lock);
147 static struct file_operations flash_fops = {
148 /* no write to the Flash, use mmap
149 * and play flash dependent tricks.
151 .owner = THIS_MODULE,
152 .llseek = flash_llseek,
156 .release = flash_release,
159 static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
161 static int __init flash_init(void)
163 struct sbus_bus *sbus;
164 struct sbus_dev *sdev = 0;
166 struct linux_ebus *ebus;
167 struct linux_ebus_device *edev = 0;
168 struct linux_prom_registers regs[2];
173 for_all_sbusdev(sdev, sbus) {
174 if (!strcmp(sdev->prom_name, "flashprom")) {
175 if (sdev->reg_addrs[0].phys_addr == sdev->reg_addrs[1].phys_addr) {
176 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
177 (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
178 flash.read_size = sdev->reg_addrs[0].reg_size;
179 flash.write_base = flash.read_base;
180 flash.write_size = flash.read_size;
182 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
183 (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
184 flash.read_size = sdev->reg_addrs[0].reg_size;
185 flash.write_base = ((unsigned long)sdev->reg_addrs[1].phys_addr) |
186 (((unsigned long)sdev->reg_addrs[1].which_io)<<32UL);
187 flash.write_size = sdev->reg_addrs[1].reg_size;
195 for_each_ebus(ebus) {
196 for_each_ebusdev(edev, ebus) {
197 if (!strcmp(edev->prom_name, "flashprom"))
205 len = prom_getproperty(edev->prom_node, "reg", (void *)regs, sizeof(regs));
206 if ((len % sizeof(regs[0])) != 0) {
207 printk("flash: Strange reg property size %d\n", len);
211 nregs = len / sizeof(regs[0]);
213 flash.read_base = edev->resource[0].start;
214 flash.read_size = regs[0].reg_size;
217 flash.write_base = edev->resource[0].start;
218 flash.write_size = regs[0].reg_size;
219 } else if (nregs == 2) {
220 flash.write_base = edev->resource[1].start;
221 flash.write_size = regs[1].reg_size;
223 printk("flash: Strange number of regs %d\n", nregs);
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);
238 err = misc_register(&flash_dev);
240 printk(KERN_ERR "flash: unable to get misc minor\n");
247 static void __exit flash_cleanup(void)
249 misc_deregister(&flash_dev);
252 module_init(flash_init);
253 module_exit(flash_cleanup);
254 MODULE_LICENSE("GPL");