drm: Add via unichrome support

Add DRM device driver for VIA Unichrome chipsets

From: Unichrome Project http://unichrome.sf.net, Erdi Chen, Thomas Hellstrom    Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/via_ds.c b/drivers/char/drm/via_ds.c
new file mode 100644
index 0000000..daf3df7
--- /dev/null
+++ b/drivers/char/drm/via_ds.c
@@ -0,0 +1,280 @@
+/*
+ * Copyright 1998-2003 VIA Technologies, Inc. All Rights Reserved.
+ * Copyright 2001-2003 S3 Graphics, Inc. All Rights Reserved.
+ * Copyright 2000 Silicon Integrated Systems Corp, Inc., HsinChu, Taiwan.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sub license,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * VIA, S3 GRAPHICS, AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+
+#include "via_ds.h"
+extern unsigned int VIA_DEBUG;
+
+set_t *via_setInit(void)
+{
+	int i;
+	set_t *set;
+	set = (set_t *) drm_alloc(sizeof(set_t), DRM_MEM_DRIVER);
+	for (i = 0; i < SET_SIZE; i++) {
+		set->list[i].free_next = i + 1;
+		set->list[i].alloc_next = -1;
+	}
+	set->list[SET_SIZE - 1].free_next = -1;
+	set->free = 0;
+	set->alloc = -1;
+	set->trace = -1;
+	return set;
+}
+
+int via_setAdd(set_t * set, ITEM_TYPE item)
+{
+	int free = set->free;
+	if (free != -1) {
+		set->list[free].val = item;
+		set->free = set->list[free].free_next;
+	} else {
+		return 0;
+	}
+	set->list[free].alloc_next = set->alloc;
+	set->alloc = free;
+	set->list[free].free_next = -1;
+	return 1;
+}
+
+int via_setDel(set_t * set, ITEM_TYPE item)
+{
+	int alloc = set->alloc;
+	int prev = -1;
+
+	while (alloc != -1) {
+		if (set->list[alloc].val == item) {
+			if (prev != -1)
+				set->list[prev].alloc_next =
+				    set->list[alloc].alloc_next;
+			else
+				set->alloc = set->list[alloc].alloc_next;
+			break;
+		}
+		prev = alloc;
+		alloc = set->list[alloc].alloc_next;
+	}
+
+	if (alloc == -1)
+		return 0;
+
+	set->list[alloc].free_next = set->free;
+	set->free = alloc;
+	set->list[alloc].alloc_next = -1;
+
+	return 1;
+}
+
+/* setFirst -> setAdd -> setNext is wrong */
+
+int via_setFirst(set_t * set, ITEM_TYPE * item)
+{
+	if (set->alloc == -1)
+		return 0;
+
+	*item = set->list[set->alloc].val;
+	set->trace = set->list[set->alloc].alloc_next;
+
+	return 1;
+}
+
+int via_setNext(set_t * set, ITEM_TYPE * item)
+{
+	if (set->trace == -1)
+		return 0;
+
+	*item = set->list[set->trace].val;
+	set->trace = set->list[set->trace].alloc_next;
+
+	return 1;
+}
+
+int via_setDestroy(set_t * set)
+{
+	drm_free(set, sizeof(set_t), DRM_MEM_DRIVER);
+
+	return 1;
+}
+
+#define ISFREE(bptr) ((bptr)->free)
+
+#define fprintf(fmt, arg...) do{}while(0)
+
+memHeap_t *via_mmInit(int ofs, int size)
+{
+	PMemBlock blocks;
+
+	if (size <= 0)
+		return 0;
+
+	blocks = (TMemBlock *) drm_calloc(1, sizeof(TMemBlock), DRM_MEM_DRIVER);
+
+	if (blocks) {
+		blocks->ofs = ofs;
+		blocks->size = size;
+		blocks->free = 1;
+		return (memHeap_t *) blocks;
+	} else
+		return 0;
+}
+
+static TMemBlock *SliceBlock(TMemBlock * p,
+			     int startofs, int size,
+			     int reserved, int alignment)
+{
+	TMemBlock *newblock;
+
+	/* break left */
+	if (startofs > p->ofs) {
+		newblock =
+		    (TMemBlock *) drm_calloc(1, sizeof(TMemBlock),
+					     DRM_MEM_DRIVER);
+		newblock->ofs = startofs;
+		newblock->size = p->size - (startofs - p->ofs);
+		newblock->free = 1;
+		newblock->next = p->next;
+		p->size -= newblock->size;
+		p->next = newblock;
+		p = newblock;
+	}
+
+	/* break right */
+	if (size < p->size) {
+		newblock =
+		    (TMemBlock *) drm_calloc(1, sizeof(TMemBlock),
+					     DRM_MEM_DRIVER);
+		newblock->ofs = startofs + size;
+		newblock->size = p->size - size;
+		newblock->free = 1;
+		newblock->next = p->next;
+		p->size = size;
+		p->next = newblock;
+	}
+
+	/* p = middle block */
+	p->align = alignment;
+	p->free = 0;
+	p->reserved = reserved;
+	return p;
+}
+
+PMemBlock via_mmAllocMem(memHeap_t * heap, int size, int align2,
+			 int startSearch)
+{
+	int mask, startofs, endofs;
+	TMemBlock *p;
+
+	if (!heap || align2 < 0 || size <= 0)
+		return NULL;
+
+	mask = (1 << align2) - 1;
+	startofs = 0;
+	p = (TMemBlock *) heap;
+
+	while (p) {
+		if (ISFREE(p)) {
+			startofs = (p->ofs + mask) & ~mask;
+
+			if (startofs < startSearch)
+				startofs = startSearch;
+
+			endofs = startofs + size;
+
+			if (endofs <= (p->ofs + p->size))
+				break;
+		}
+
+		p = p->next;
+	}
+
+	if (!p)
+		return NULL;
+
+	p = SliceBlock(p, startofs, size, 0, mask + 1);
+	p->heap = heap;
+
+	return p;
+}
+
+static __inline__ int Join2Blocks(TMemBlock * p)
+{
+	if (p->free && p->next && p->next->free) {
+		TMemBlock *q = p->next;
+		p->size += q->size;
+		p->next = q->next;
+		drm_free(q, sizeof(TMemBlock), DRM_MEM_DRIVER);
+
+		return 1;
+	}
+
+	return 0;
+}
+
+int via_mmFreeMem(PMemBlock b)
+{
+	TMemBlock *p, *prev;
+
+	if (!b)
+		return 0;
+
+	if (!b->heap) {
+		fprintf(stderr, "no heap\n");
+
+		return -1;
+	}
+
+	p = b->heap;
+	prev = NULL;
+
+	while (p && p != b) {
+		prev = p;
+		p = p->next;
+	}
+
+	if (!p || p->free || p->reserved) {
+		if (!p)
+			fprintf(stderr, "block not found in heap\n");
+		else if (p->free)
+			fprintf(stderr, "block already free\n");
+		else
+			fprintf(stderr, "block is reserved\n");
+
+		return -1;
+	}
+
+	p->free = 1;
+	Join2Blocks(p);
+
+	if (prev)
+		Join2Blocks(prev);
+
+	return 0;
+}