drm/nouveau: add support for gm204

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_bios.c

@@ -1258,7 +1258,7 @@ olddcb_table(struct drm_device *dev)
 		return NULL;
 	}
 
-	if (dcb[0] >= 0x41) {
+	if (dcb[0] >= 0x42) {
 		NV_WARN(drm, "DCB version 0x%02x unknown\n", dcb[0]);
 		return NULL;
 	} else
@@ -1481,16 +1481,19 @@ parse_dcb20_entry(struct drm_device *dev, struct dcb_table *dcb,
 			entry->dpconf.link_bw = 540000;
 			break;
 		}
-		switch ((conf & 0x0f000000) >> 24) {
-		case 0xf:
-			entry->dpconf.link_nr = 4;
-			break;
-		case 0x3:
-			entry->dpconf.link_nr = 2;
-			break;
-		default:
-			entry->dpconf.link_nr = 1;
-			break;
+		entry->dpconf.link_nr = (conf & 0x0f000000) >> 24;
+		if (dcb->version < 0x41) {
+			switch (entry->dpconf.link_nr) {
+			case 0xf:
+				entry->dpconf.link_nr = 4;
+				break;
+			case 0x3:
+				entry->dpconf.link_nr = 2;
+				break;
+			default:
+				entry->dpconf.link_nr = 1;
+				break;
+			}
 		}
 		link = entry->dpconf.sor.link;
 		entry->i2c_index += NV_I2C_AUX(0);

drivers/gpu/drm/nouveau/nouveau_display.c

@@ -479,6 +479,7 @@ nouveau_display_create(struct drm_device *dev)
 
 	if (nouveau_modeset != 2 && drm->vbios.dcb.entries) {
 		static const u16 oclass[] = {
+			GM204_DISP,
 			GM107_DISP,
 			GK110_DISP,
 			GK104_DISP,

drivers/gpu/drm/nouveau/nv50_display.c

@@ -266,6 +266,7 @@ nv50_core_create(struct nvif_object *disp, u64 syncbuf, struct nv50_mast *core)
 		.pushbuf = 0xb0007d00,
 	};
 	static const u32 oclass[] = {
+		GM204_DISP_CORE_CHANNEL_DMA,
 		GM107_DISP_CORE_CHANNEL_DMA,
 		GK110_DISP_CORE_CHANNEL_DMA,
 		GK104_DISP_CORE_CHANNEL_DMA,