/*
 * (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 <linux/export.h>
#include <asm/prom.h>
#include <asm/dcr.h>

#ifdef CONFIG_PPC_DCR_MMIO
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;
}
#endif

#if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)

bool dcr_map_ok_generic(dcr_host_t host)
{
        if (host.type == DCR_HOST_NATIVE)
                return dcr_map_ok_native(host.host.native);
        else if (host.type == DCR_HOST_MMIO)
                return dcr_map_ok_mmio(host.host.mmio);
        else
                return 0;
}
EXPORT_SYMBOL_GPL(dcr_map_ok_generic);

dcr_host_t dcr_map_generic(struct device_node *dev,
                           unsigned int dcr_n,
                           unsigned int dcr_c)
{
        dcr_host_t host;
        struct device_node *dp;
        const char *prop;

        host.type = DCR_HOST_INVALID;

        dp = find_dcr_parent(dev);
        if (dp == NULL)
                return host;

        prop = of_get_property(dp, "dcr-access-method", NULL);

        pr_debug("dcr_map_generic(dcr-access-method = %s)\n", prop);

        if (!strcmp(prop, "native")) {
                host.type = DCR_HOST_NATIVE;
                host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
        } else if (!strcmp(prop, "mmio")) {
                host.type = DCR_HOST_MMIO;
                host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
        }

        of_node_put(dp);
        return host;
}
EXPORT_SYMBOL_GPL(dcr_map_generic);

void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
{
        if (host.type == DCR_HOST_NATIVE)
                dcr_unmap_native(host.host.native, dcr_c);
        else if (host.type == DCR_HOST_MMIO)
                dcr_unmap_mmio(host.host.mmio, dcr_c);
        else /* host.type == DCR_HOST_INVALID */
                WARN_ON(true);
}
EXPORT_SYMBOL_GPL(dcr_unmap_generic);

u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
{
        if (host.type == DCR_HOST_NATIVE)
                return dcr_read_native(host.host.native, dcr_n);
        else if (host.type == DCR_HOST_MMIO)
                return dcr_read_mmio(host.host.mmio, dcr_n);
        else /* host.type == DCR_HOST_INVALID */
                WARN_ON(true);
        return 0;
}
EXPORT_SYMBOL_GPL(dcr_read_generic);

void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
{
        if (host.type == DCR_HOST_NATIVE)
                dcr_write_native(host.host.native, dcr_n, value);
        else if (host.type == DCR_HOST_MMIO)
                dcr_write_mmio(host.host.mmio, dcr_n, value);
        else /* host.type == DCR_HOST_INVALID */
                WARN_ON(true);
}
EXPORT_SYMBOL_GPL(dcr_write_generic);

#endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */

unsigned int dcr_resource_start(const 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(const 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);

#ifdef CONFIG_PPC_DCR_MMIO

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 = OF_BAD_ADDR;

        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)
                goto done;

        /* 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;

 done:
        of_node_put(dp);
        return ret;
}

dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
                             unsigned int dcr_n,
                             unsigned int dcr_c)
{
        dcr_host_mmio_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%llx, stride: 0x%x\n",
                 (unsigned long long) 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_mmio);

void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
{
        dcr_host_mmio_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_mmio);

#endif /* defined(CONFIG_PPC_DCR_MMIO) */

#ifdef CONFIG_PPC_DCR_NATIVE
DEFINE_SPINLOCK(dcr_ind_lock);
#endif  /* defined(CONFIG_PPC_DCR_NATIVE) */