/* $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/config.h>#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>static spinlock_t flash_lock = SPIN_LOCK_UNLOCKED;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	152static intflash_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 << 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));	pgprot_val(vma->vm_page_prot) &= ~(_PAGE_CACHE);	pgprot_val(vma->vm_page_prot) |= _PAGE_E;	vma->vm_flags |= (VM_SHM | VM_LOCKED);	if (remap_page_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))		return -EAGAIN;			return 0;}static long longflash_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_tflash_read(struct file * file, char * 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 = readb(flash.read_base + p + i);		if (put_user(data, buf))			return -EFAULT;		buf++;	}	file->f_pos += count;	return count;}static intflash_open(struct inode *inode, struct file *file){	if (test_and_set_bit(0, (void *)&flash.busy) != 0)		return -EBUSY;	return 0;}static intflash_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 };EXPORT_NO_SYMBOLS;static int __init flash_init(void){	struct sbus_bus *sbus;	struct sbus_dev *sdev = 0;	struct linux_ebus *ebus;	struct linux_ebus_device *edev = 0;	struct linux_prom_registers regs[2];	int len, err, nregs;	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		for_each_ebus(ebus) {			for_each_ebusdev(edev, ebus) {				if (!strcmp(edev->prom_name, "flashprom"))					goto ebus_done;			}		}	ebus_done:		if (!edev)			return -ENODEV;		len = prom_getproperty(edev->prom_node, "reg", (void *)regs, sizeof(regs));		if ((len % sizeof(regs[0])) != 0) {			printk("flash: Strange reg property size %d\n", len);			return -ENODEV;		}		nregs = len / sizeof(regs[0]);		flash.read_base = edev->resource[0].start;		flash.read_size = regs[0].reg_size;		if (nregs == 1) {			flash.write_base = edev->resource[0].start;			flash.write_size = regs[0].reg_size;		} else if (nregs == 2) {			flash.write_base = edev->resource[1].start;			flash.write_size = 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");