drm/nouveau: correct memtiming table parsing for nv4x

In line with envytools, verified on 4 or 5 BIOS'es.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Roy Spliet <r.spliet@student.tudelft.nl>

drivers/gpu/drm/nouveau/nouveau_mem.c

@@ -552,6 +552,7 @@ nouveau_mem_timing_init(struct drm_device *dev)
 	u8 tRC;		/* Byte 9 */
 	u8 tUNK_10, tUNK_11, tUNK_12, tUNK_13, tUNK_14;
 	u8 tUNK_18, tUNK_19, tUNK_20, tUNK_21;
+	u8 magic_number = 0; /* Yeah... sorry*/
 	u8 *mem = NULL, *entry;
 	int i, recordlen, entries;
 
@@ -596,6 +597,12 @@ nouveau_mem_timing_init(struct drm_device *dev)
 	if (!memtimings->timing)
 		return;
 
+	/* Get "some number" from the timing reg for NV_40
+	 * Used in calculations later */
+	if(dev_priv->card_type == NV_40) {
+		magic_number = (nv_rd32(dev,0x100228) & 0x0f000000) >> 24;
+	}
+
 	entry = mem + mem[1];
 	for (i = 0; i < entries; i++, entry += recordlen) {
 		struct nouveau_pm_memtiming *timing = &pm->memtimings.timing[i];
@@ -635,36 +642,51 @@ nouveau_mem_timing_init(struct drm_device *dev)
 
 		/* XXX: I don't trust the -1's and +1's... they must come
 		 *      from somewhere! */
-		timing->reg_100224 = ((tUNK_0 + tUNK_19 + 1) << 24 |
+		timing->reg_100224 = (tUNK_0 + tUNK_19 + 1 + magic_number) << 24 |
 				      tUNK_18 << 16 |
-				      (tUNK_1 + tUNK_19 + 1) << 8 |
-				      (tUNK_2 - 1));
+				      (tUNK_1 + tUNK_19 + 1 + magic_number) << 8;
+		if(dev_priv->chipset == 0xa8) {
+			timing->reg_100224 |= (tUNK_2 - 1);
+		} else {
+			timing->reg_100224 |= (tUNK_2 + 2 - magic_number);
+		}
 
 		timing->reg_100228 = (tUNK_12 << 16 | tUNK_11 << 8 | tUNK_10);
-		if(recordlen > 19) {
-			timing->reg_100228 += (tUNK_19 - 1) << 24;
-		}/* I cannot back-up this else-statement right now
-			 else {
-			timing->reg_100228 += tUNK_12 << 24;
-		}*/
-
-		/* XXX: reg_10022c */
-		timing->reg_10022c = tUNK_2 - 1;
-
-		timing->reg_100230 = (tUNK_20 << 24 | tUNK_21 << 16 |
-				      tUNK_13 << 8  | tUNK_13);
-
-		/* XXX: +6? */
-		timing->reg_100234 = (tRAS << 24 | (tUNK_19 + 6) << 8 | tRC);
-		timing->reg_100234 += max(tUNK_10,tUNK_11) << 16;
-
-		/* XXX; reg_100238, reg_10023c
-		 * reg: 0x00??????
-		 * reg_10023c:
-		 *      0 for pre-NV50 cards
-		 *      0x????0202 for NV50+ cards (empirical evidence) */
-		if(dev_priv->card_type >= NV_50) {
+		if(dev_priv->chipset >= 0xa3 && dev_priv->chipset < 0xaa) {
+			timing->reg_100228 |= (tUNK_19 - 1) << 24;
+		}
+
+		if(dev_priv->card_type == NV_40) {
+			/* NV40: don't know what the rest of the regs are..
+			 * And don't need to know either */
+			timing->reg_100228 |= 0x20200000 | magic_number << 24;
+		} else if(dev_priv->card_type >= NV_50) {
+			/* XXX: reg_10022c */
+			timing->reg_10022c = tUNK_2 - 1;
+
+			timing->reg_100230 = (tUNK_20 << 24 | tUNK_21 << 16 |
+						  tUNK_13 << 8  | tUNK_13);
+
+			timing->reg_100234 = (tRAS << 24 | tRC);
+			timing->reg_100234 += max(tUNK_10,tUNK_11) << 16;
+
+			if(dev_priv->chipset < 0xa3) {
+				timing->reg_100234 |= (tUNK_2 + 2) << 8;
+			} else {
+				/* XXX: +6? */
+				timing->reg_100234 |= (tUNK_19 + 6) << 8;
+			}
+
+			/* XXX; reg_100238, reg_10023c
+			 * reg_100238: 0x00??????
+			 * reg_10023c: 0x!!??0202 for NV50+ cards (empirical evidence) */
 			timing->reg_10023c = 0x202;
+			if(dev_priv->chipset < 0xa3) {
+				timing->reg_10023c |= 0x4000000 | (tUNK_2 - 1) << 16;
+			} else {
+				/* currently unknown
+				 * 10023c seen as 06xxxxxx, 0bxxxxxx or 0fxxxxxx */
+			}
 		}
 
 		NV_DEBUG(dev, "Entry %d: 220: %08x %08x %08x %08x\n", i,
@@ -675,7 +697,7 @@ nouveau_mem_timing_init(struct drm_device *dev)
 			 timing->reg_100238, timing->reg_10023c);
 	}
 
-	memtimings->nr_timing  = entries;
+	memtimings->nr_timing = entries;
 	memtimings->supported = true;
 }