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