256 lines
5.8 KiB
C
256 lines
5.8 KiB
C
/* $Id: flash.c,v 1.25 2001/12/21 04:56:16 davem Exp $
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* flash.c: Allow mmap access to the OBP Flash, for OBP updates.
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*
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* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/miscdevice.h>
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#include <linux/slab.h>
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#include <linux/fcntl.h>
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#include <linux/poll.h>
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#include <linux/init.h>
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#include <linux/smp_lock.h>
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#include <linux/spinlock.h>
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#include <linux/mm.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/io.h>
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#include <asm/sbus.h>
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#include <asm/ebus.h>
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#include <asm/upa.h>
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static DEFINE_SPINLOCK(flash_lock);
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static struct {
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unsigned long read_base; /* Physical read address */
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unsigned long write_base; /* Physical write address */
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unsigned long read_size; /* Size of read area */
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unsigned long write_size; /* Size of write area */
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unsigned long busy; /* In use? */
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} flash;
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#define FLASH_MINOR 152
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static int
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flash_mmap(struct file *file, struct vm_area_struct *vma)
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{
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unsigned long addr;
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unsigned long size;
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spin_lock(&flash_lock);
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if (flash.read_base == flash.write_base) {
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addr = flash.read_base;
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size = flash.read_size;
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} else {
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if ((vma->vm_flags & VM_READ) &&
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(vma->vm_flags & VM_WRITE)) {
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spin_unlock(&flash_lock);
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return -EINVAL;
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}
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if (vma->vm_flags & VM_READ) {
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addr = flash.read_base;
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size = flash.read_size;
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} else if (vma->vm_flags & VM_WRITE) {
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addr = flash.write_base;
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size = flash.write_size;
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} else {
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spin_unlock(&flash_lock);
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return -ENXIO;
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}
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}
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spin_unlock(&flash_lock);
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if ((vma->vm_pgoff << PAGE_SHIFT) > size)
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return -ENXIO;
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addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
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if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
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size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
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vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
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if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
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return -EAGAIN;
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return 0;
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}
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static long long
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flash_llseek(struct file *file, long long offset, int origin)
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{
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lock_kernel();
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switch (origin) {
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case 0:
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file->f_pos = offset;
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break;
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case 1:
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file->f_pos += offset;
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if (file->f_pos > flash.read_size)
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file->f_pos = flash.read_size;
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break;
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case 2:
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file->f_pos = flash.read_size;
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break;
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default:
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unlock_kernel();
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return -EINVAL;
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}
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unlock_kernel();
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return file->f_pos;
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}
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static ssize_t
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flash_read(struct file * file, char __user * buf,
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size_t count, loff_t *ppos)
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{
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unsigned long p = file->f_pos;
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int i;
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if (count > flash.read_size - p)
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count = flash.read_size - p;
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for (i = 0; i < count; i++) {
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u8 data = upa_readb(flash.read_base + p + i);
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if (put_user(data, buf))
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return -EFAULT;
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buf++;
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}
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file->f_pos += count;
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return count;
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}
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static int
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flash_open(struct inode *inode, struct file *file)
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{
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if (test_and_set_bit(0, (void *)&flash.busy) != 0)
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return -EBUSY;
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return 0;
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}
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static int
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flash_release(struct inode *inode, struct file *file)
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{
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spin_lock(&flash_lock);
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flash.busy = 0;
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spin_unlock(&flash_lock);
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return 0;
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}
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static const struct file_operations flash_fops = {
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/* no write to the Flash, use mmap
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* and play flash dependent tricks.
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*/
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.owner = THIS_MODULE,
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.llseek = flash_llseek,
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.read = flash_read,
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.mmap = flash_mmap,
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.open = flash_open,
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.release = flash_release,
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};
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static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
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static int __init flash_init(void)
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{
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struct sbus_bus *sbus;
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struct sbus_dev *sdev = NULL;
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#ifdef CONFIG_PCI
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struct linux_ebus *ebus;
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struct linux_ebus_device *edev = NULL;
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struct linux_prom_registers regs[2];
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int len, nregs;
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#endif
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int err;
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for_all_sbusdev(sdev, sbus) {
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if (!strcmp(sdev->prom_name, "flashprom")) {
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if (sdev->reg_addrs[0].phys_addr == sdev->reg_addrs[1].phys_addr) {
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flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
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(((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
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flash.read_size = sdev->reg_addrs[0].reg_size;
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flash.write_base = flash.read_base;
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flash.write_size = flash.read_size;
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} else {
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flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
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(((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
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flash.read_size = sdev->reg_addrs[0].reg_size;
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flash.write_base = ((unsigned long)sdev->reg_addrs[1].phys_addr) |
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(((unsigned long)sdev->reg_addrs[1].which_io)<<32UL);
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flash.write_size = sdev->reg_addrs[1].reg_size;
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}
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flash.busy = 0;
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break;
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}
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}
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if (!sdev) {
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#ifdef CONFIG_PCI
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const struct linux_prom_registers *ebus_regs;
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for_each_ebus(ebus) {
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for_each_ebusdev(edev, ebus) {
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if (!strcmp(edev->prom_node->name, "flashprom"))
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goto ebus_done;
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}
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}
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ebus_done:
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if (!edev)
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return -ENODEV;
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ebus_regs = of_get_property(edev->prom_node, "reg", &len);
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if (!ebus_regs || (len % sizeof(regs[0])) != 0) {
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printk("flash: Strange reg property size %d\n", len);
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return -ENODEV;
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}
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nregs = len / sizeof(ebus_regs[0]);
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flash.read_base = edev->resource[0].start;
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flash.read_size = ebus_regs[0].reg_size;
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if (nregs == 1) {
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flash.write_base = edev->resource[0].start;
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flash.write_size = ebus_regs[0].reg_size;
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} else if (nregs == 2) {
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flash.write_base = edev->resource[1].start;
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flash.write_size = ebus_regs[1].reg_size;
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} else {
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printk("flash: Strange number of regs %d\n", nregs);
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return -ENODEV;
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}
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flash.busy = 0;
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#else
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return -ENODEV;
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#endif
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}
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printk("OBP Flash: RD %lx[%lx] WR %lx[%lx]\n",
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flash.read_base, flash.read_size,
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flash.write_base, flash.write_size);
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err = misc_register(&flash_dev);
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if (err) {
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printk(KERN_ERR "flash: unable to get misc minor\n");
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return err;
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}
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return 0;
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}
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static void __exit flash_cleanup(void)
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{
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misc_deregister(&flash_dev);
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}
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module_init(flash_init);
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module_exit(flash_cleanup);
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MODULE_LICENSE("GPL");
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