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-rw-r--r--arch/powerpc/sysdev/dcr.c137
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) */