From e7fade3ac4559214ab0508dc54a71a3d1f522afb Mon Sep 17 00:00:00 2001
From: Daniel Hellstrom <daniel@gaisler.com>
Date: Mon, 28 Nov 2011 09:52:03 +0100
Subject: DRVMGR: added driver manager to cpukit/libdrvmgr

---
 cpukit/libdrvmgr/drvmgr_translate.c | 149 ++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 cpukit/libdrvmgr/drvmgr_translate.c

(limited to 'cpukit/libdrvmgr/drvmgr_translate.c')

diff --git a/cpukit/libdrvmgr/drvmgr_translate.c b/cpukit/libdrvmgr/drvmgr_translate.c
new file mode 100644
index 0000000000..7febf77d60
--- /dev/null
+++ b/cpukit/libdrvmgr/drvmgr_translate.c
@@ -0,0 +1,149 @@
+/* Driver Manager Driver Translate Interface Implementation
+ *
+ * COPYRIGHT (c) 2010.
+ * Cobham Gaisler AB.
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+/*
+ * Used by device drivers. The functions rely on that the parent bus driver
+ * has implemented the neccessary operations correctly.
+ *
+ * The translate functions are used to translate addresses between buses
+ * for DMA cores located on a "remote" bus, or for memory-mapped obtaining
+ * an address that can be used to access an remote bus.
+ *
+ * For example, PCI I/O might be memory-mapped at the PCI Host bridge,
+ * say address 0xfff10000-0xfff1ffff is mapped to the PCI I/O address
+ * of 0x00000000-0x0000ffff. The PCI Host bridge driver may then set up
+ * a map so that a driver that get PCI address 0x100 can translate that
+ * into 0xfff10100.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <drvmgr/drvmgr.h>
+#include "drvmgr_internal.h"
+
+unsigned int drvmgr_translate_bus(
+	struct drvmgr_bus *from,
+	struct drvmgr_bus *to,
+	int reverse,
+	void *src_address,
+	void **dst_address)
+{
+	struct drvmgr_bus *path[16];
+	int dir, levels, i;
+	void *dst, *from_adr, *to_adr;
+	struct drvmgr_map_entry *map;
+	struct drvmgr_bus *bus;
+	unsigned int sz;
+	struct drvmgr_bus *bus_bot, *bus_top;
+
+	dst = src_address;
+	sz = 0xffffffff;
+
+	if (from == to) /* no need translating addresses when on same bus */
+		goto out;
+
+	/* Always find translation path from remote bus towards root bus. All
+	 * buses have root bus has parent at some level
+	 */
+	if (from->depth > to->depth) {
+		bus_bot = from;
+		bus_top = to;
+		dir = 0;
+	} else {
+		bus_bot = to;
+		bus_top = from;
+		dir = 1;
+	}
+	levels = bus_bot->depth - bus_top->depth;
+	if (levels >= 16)
+		return 0; /* Does not support such a big depth */
+	i = 0;
+	while ((bus_bot != NULL) && bus_bot != bus_top) {
+		if (dir)
+			path[(levels - 1) - i] = bus_bot;
+		else
+			path[i] = bus_bot;
+		i++;
+		bus_bot = bus_bot->dev->parent;
+	}
+	if (bus_bot == NULL)
+		return 0; /* from -> to is not linearly connected */
+
+	for (i = 0; i < levels; i++) {
+		bus = path[i];
+
+		if ((dir && reverse) || (!dir && !reverse))
+			map = bus->maps_up;
+		else
+			map = bus->maps_down;
+
+		if (map == NULL)
+			continue; /* No translation needed - 1:1 mapping */
+
+		if (map == DRVMGR_TRANSLATE_NO_BRIDGE) {
+			sz = 0;
+			break; /* No bridge interface in this direction */
+		}
+
+		while (map->size != 0) {
+			if (reverse) {
+				/* Opposite direction */
+				from_adr = map->to_adr;
+				to_adr = map->from_adr;
+			} else {
+				from_adr = map->from_adr;
+				to_adr = map->to_adr;
+			}
+
+			if ((dst >= from_adr) &&
+			    (dst <= (from_adr + (map->size - 1)))) {
+				if (((from_adr + (map->size - 1)) - dst) < sz)
+					sz = (from_adr + (map->size - 1)) - dst;
+				dst = (dst - from_adr) + to_adr;
+				break;
+			}
+			map++;
+		}
+		/* quit if no matching translation information */
+		if (map->size == 0) {
+			sz = 0;
+			break;
+		}
+	}
+
+out:
+	if (dst_address)
+		*dst_address = dst;
+
+	return sz;
+}
+
+unsigned int drvmgr_translate(
+	struct drvmgr_dev *dev,
+	unsigned int options,
+	void *src_address,
+	void **dst_address)
+{
+	struct drvmgr_bus *to, *from;
+	int rev = 0;
+
+	rev = (~options) & 1;
+	if ((options == CPUMEM_TO_DMA) || (options == DMAMEM_FROM_CPU)) {
+		from = drv_mgr.root_dev.bus;
+		to = dev->parent;
+	} else { /* CPUMEM_FROM_DMA || DMAMEM_TO_CPU */
+		from = dev->parent;
+		to = drv_mgr.root_dev.bus;
+	}
+
+	return drvmgr_translate_bus(from, to, rev, src_address, dst_address);
+}
-- 
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