You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
158 lines
3.7 KiB
158 lines
3.7 KiB
/*
|
|
* memory mapped NVRAM
|
|
*
|
|
* (C) Copyright IBM Corp. 2005
|
|
*
|
|
* Authors : Utz Bacher <utz.bacher@de.ibm.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/types.h>
|
|
|
|
#include <asm/machdep.h>
|
|
#include <asm/nvram.h>
|
|
#include <asm/prom.h>
|
|
|
|
static void __iomem *mmio_nvram_start;
|
|
static long mmio_nvram_len;
|
|
static DEFINE_SPINLOCK(mmio_nvram_lock);
|
|
|
|
static ssize_t mmio_nvram_read(char *buf, size_t count, loff_t *index)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (*index >= mmio_nvram_len)
|
|
return 0;
|
|
if (*index + count > mmio_nvram_len)
|
|
count = mmio_nvram_len - *index;
|
|
|
|
spin_lock_irqsave(&mmio_nvram_lock, flags);
|
|
|
|
memcpy_fromio(buf, mmio_nvram_start + *index, count);
|
|
|
|
spin_unlock_irqrestore(&mmio_nvram_lock, flags);
|
|
|
|
*index += count;
|
|
return count;
|
|
}
|
|
|
|
static unsigned char mmio_nvram_read_val(int addr)
|
|
{
|
|
unsigned long flags;
|
|
unsigned char val;
|
|
|
|
if (addr >= mmio_nvram_len)
|
|
return 0xff;
|
|
|
|
spin_lock_irqsave(&mmio_nvram_lock, flags);
|
|
|
|
val = ioread8(mmio_nvram_start + addr);
|
|
|
|
spin_unlock_irqrestore(&mmio_nvram_lock, flags);
|
|
|
|
return val;
|
|
}
|
|
|
|
static ssize_t mmio_nvram_write(char *buf, size_t count, loff_t *index)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (*index >= mmio_nvram_len)
|
|
return 0;
|
|
if (*index + count > mmio_nvram_len)
|
|
count = mmio_nvram_len - *index;
|
|
|
|
spin_lock_irqsave(&mmio_nvram_lock, flags);
|
|
|
|
memcpy_toio(mmio_nvram_start + *index, buf, count);
|
|
|
|
spin_unlock_irqrestore(&mmio_nvram_lock, flags);
|
|
|
|
*index += count;
|
|
return count;
|
|
}
|
|
|
|
static void mmio_nvram_write_val(int addr, unsigned char val)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (addr < mmio_nvram_len) {
|
|
spin_lock_irqsave(&mmio_nvram_lock, flags);
|
|
|
|
iowrite8(val, mmio_nvram_start + addr);
|
|
|
|
spin_unlock_irqrestore(&mmio_nvram_lock, flags);
|
|
}
|
|
}
|
|
|
|
static ssize_t mmio_nvram_get_size(void)
|
|
{
|
|
return mmio_nvram_len;
|
|
}
|
|
|
|
int __init mmio_nvram_init(void)
|
|
{
|
|
struct device_node *nvram_node;
|
|
unsigned long nvram_addr;
|
|
struct resource r;
|
|
int ret;
|
|
|
|
nvram_node = of_find_node_by_type(NULL, "nvram");
|
|
if (!nvram_node)
|
|
nvram_node = of_find_compatible_node(NULL, NULL, "nvram");
|
|
if (!nvram_node) {
|
|
printk(KERN_WARNING "nvram: no node found in device-tree\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
ret = of_address_to_resource(nvram_node, 0, &r);
|
|
if (ret) {
|
|
printk(KERN_WARNING "nvram: failed to get address (err %d)\n",
|
|
ret);
|
|
goto out;
|
|
}
|
|
nvram_addr = r.start;
|
|
mmio_nvram_len = resource_size(&r);
|
|
if ( (!mmio_nvram_len) || (!nvram_addr) ) {
|
|
printk(KERN_WARNING "nvram: address or length is 0\n");
|
|
ret = -EIO;
|
|
goto out;
|
|
}
|
|
|
|
mmio_nvram_start = ioremap(nvram_addr, mmio_nvram_len);
|
|
if (!mmio_nvram_start) {
|
|
printk(KERN_WARNING "nvram: failed to ioremap\n");
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
printk(KERN_INFO "mmio NVRAM, %luk at 0x%lx mapped to %p\n",
|
|
mmio_nvram_len >> 10, nvram_addr, mmio_nvram_start);
|
|
|
|
ppc_md.nvram_read_val = mmio_nvram_read_val;
|
|
ppc_md.nvram_write_val = mmio_nvram_write_val;
|
|
ppc_md.nvram_read = mmio_nvram_read;
|
|
ppc_md.nvram_write = mmio_nvram_write;
|
|
ppc_md.nvram_size = mmio_nvram_get_size;
|
|
|
|
out:
|
|
of_node_put(nvram_node);
|
|
return ret;
|
|
}
|
|
|