linux-sg2042/arch/powerpc/sysdev/dcr.c

142 lines
3.7 KiB
C

/*
* (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
* <benh@kernel.crashing.org>
*
* 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#undef DEBUG
#include <linux/kernel.h>
#include <asm/prom.h>
#include <asm/dcr.h>
unsigned int dcr_resource_start(struct device_node *np, unsigned int index)
{
unsigned int ds;
const u32 *dr = of_get_property(np, "dcr-reg", &ds);
if (dr == NULL || ds & 1 || index >= (ds / 8))
return 0;
return dr[index * 2];
}
EXPORT_SYMBOL_GPL(dcr_resource_start);
unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
{
unsigned int ds;
const u32 *dr = of_get_property(np, "dcr-reg", &ds);
if (dr == NULL || ds & 1 || index >= (ds / 8))
return 0;
return dr[index * 2 + 1];
}
EXPORT_SYMBOL_GPL(dcr_resource_len);
#ifndef CONFIG_PPC_DCR_NATIVE
static struct device_node * find_dcr_parent(struct device_node * node)
{
struct device_node *par, *tmp;
const u32 *p;
for (par = of_node_get(node); par;) {
if (of_get_property(par, "dcr-controller", NULL))
break;
p = of_get_property(par, "dcr-parent", NULL);
tmp = par;
if (p == NULL)
par = of_get_parent(par);
else
par = of_find_node_by_phandle(*p);
of_node_put(tmp);
}
return par;
}
u64 of_translate_dcr_address(struct device_node *dev,
unsigned int dcr_n,
unsigned int *out_stride)
{
struct device_node *dp;
const u32 *p;
unsigned int stride;
u64 ret;
dp = find_dcr_parent(dev);
if (dp == NULL)
return OF_BAD_ADDR;
/* Stride is not properly defined yet, default to 0x10 for Axon */
p = of_get_property(dp, "dcr-mmio-stride", NULL);
stride = (p == NULL) ? 0x10 : *p;
/* XXX FIXME: Which property name is to use of the 2 following ? */
p = of_get_property(dp, "dcr-mmio-range", NULL);
if (p == NULL)
p = of_get_property(dp, "dcr-mmio-space", NULL);
if (p == NULL)
return OF_BAD_ADDR;
/* Maybe could do some better range checking here */
ret = of_translate_address(dp, p);
if (ret != OF_BAD_ADDR)
ret += (u64)(stride) * (u64)dcr_n;
if (out_stride)
*out_stride = stride;
return ret;
}
dcr_host_t dcr_map(struct device_node *dev, unsigned int dcr_n,
unsigned int dcr_c)
{
dcr_host_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
u64 addr;
pr_debug("dcr_map(%s, 0x%x, 0x%x)\n",
dev->full_name, dcr_n, dcr_c);
addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
pr_debug("translates to addr: 0x%lx, stride: 0x%x\n",
addr, ret.stride);
if (addr == OF_BAD_ADDR)
return ret;
pr_debug("mapping 0x%x bytes\n", dcr_c * ret.stride);
ret.token = ioremap(addr, dcr_c * ret.stride);
if (ret.token == NULL)
return ret;
pr_debug("mapped at 0x%p -> base is 0x%p\n",
ret.token, ret.token - dcr_n * ret.stride);
ret.token -= dcr_n * ret.stride;
return ret;
}
EXPORT_SYMBOL_GPL(dcr_map);
void dcr_unmap(dcr_host_t host, unsigned int dcr_c)
{
dcr_host_t h = host;
if (h.token == NULL)
return;
h.token += host.base * h.stride;
iounmap(h.token);
h.token = NULL;
}
EXPORT_SYMBOL_GPL(dcr_unmap);
#endif /* !defined(CONFIG_PPC_DCR_NATIVE) */