kernel-ark/arch/powerpc/sysdev/mmio_nvram.c
Benjamin Herrenschmidt 6984ee797a [POWERPC] Fix cell's mmio nvram to properly parse device tree
The mmio nvram driver (used by cell only atm) isn't properly parsing
the device-tree, meaning that nvram isn't found correctly on the new
Cell blades.  It works ok for old blades where the nvram is at the
root of the device tree but fails on Malta and CAB when it's hanging
off axon.  This fixes it by using the proper OF parsing functions.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-01-22 21:27:35 +11:00

125 lines
3.0 KiB
C

/*
* 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 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 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) {
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 = r.end - r.start + 1;
if ( (!mmio_nvram_len) || (!nvram_addr) ) {
printk(KERN_WARNING "nvram: address or lenght 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 = 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;
}