1 files changed, 137 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
new file mode 100644
index 000000000000..dffeeaeca1d9
--- /dev/null
+++ b/arch/powerpc/sysdev/dcr.c
@@ -0,0 +1,137 @@
+/*
+ * (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 = get_property(np, "dcr-reg", &ds);
+
+        if (dr == NULL || ds & 1 || index >= (ds / 8))
+                return 0;
+
+        return dr[index * 2];
+}
+
+unsigned int dcr_resource_len(struct device_node *np, unsigned int index)
+{
+        unsigned int ds;
+        const u32 *dr = get_property(np, "dcr-reg", &ds);
+
+        if (dr == NULL || ds & 1 || index >= (ds / 8))
+                return 0;
+
+        return dr[index * 2 + 1];
+}
+
+#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 (get_property(par, "dcr-controller", NULL))
+                        break;
+                p = 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 = 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 = get_property(dp, "dcr-mmio-range", NULL);
+        if (p == NULL)
+                p = 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 };
+        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;
+}
+
+void dcr_unmap(dcr_host_t host, unsigned int dcr_n, unsigned int dcr_c)
+{
+        dcr_host_t h = host;
+
+        if (h.token == NULL)
+                return;
+        h.token -= dcr_n * h.stride;
+        iounmap(h.token);
+        h.token = NULL;
+}
+
+#endif /* !defined(CONFIG_PPC_DCR_NATIVE) */