drm/nva3/pm: another few magic regs, and slightly better 0x004018 handling

Not entirely convinced 0x004018 transitions are correct yet, but, it's
an improvement.

The 750MHz value comes from fiddling with the binary driver + coolbits on
two different DDR3 NVA8 chipsets (T510 NVS3100M, and NVS300), not a clue
where this number comes from.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nva3_pm.c

@@ -248,6 +248,8 @@ struct nva3_pm_state {
 	u8  rammap_len;
 	u8 *ramcfg;
 	u8  ramcfg_len;
+	u32 r004018;
+	u32 r100760;
 };
 
 void *
@@ -383,19 +385,19 @@ mclk_clock_set(struct nouveau_mem_exec_func *exec)
 	if (!(ctrl & 0x00000008) && info->mclk.pll) {
 		nv_wr32(dev, 0x004000, (ctrl |=  0x00000008));
 		nv_mask(dev, 0x1110e0, 0x00088000, 0x00088000);
-		nv_wr32(dev, 0x004018, 0x00001000); /*XXX*/
+		nv_wr32(dev, 0x004018, 0x00001000);
 		nv_wr32(dev, 0x004000, (ctrl &= ~0x00000001));
 		nv_wr32(dev, 0x004004, info->mclk.pll);
 		nv_wr32(dev, 0x004000, (ctrl |=  0x00000001));
 		udelay(64);
-		nv_wr32(dev, 0x004018, 0x10005000); /*XXX*/
+		nv_wr32(dev, 0x004018, 0x00005000 | info->r004018);
 		udelay(20);
 	} else
 	if (!info->mclk.pll) {
 		nv_mask(dev, 0x004168, 0x003f3040, info->mclk.clk);
 		nv_wr32(dev, 0x004000, (ctrl |= 0x00000008));
 		nv_mask(dev, 0x1110e0, 0x00088000, 0x00088000);
-		nv_wr32(dev, 0x004018, 0x1000d000); /*XXX*/
+		nv_wr32(dev, 0x004018, 0x0000d000 | info->r004018);
 	}
 
 	if (info->rammap) {
@@ -414,6 +416,9 @@ mclk_clock_set(struct nouveau_mem_exec_func *exec)
 		} else {
 			nv_mask(dev, 0x10053c, 0x00001000, 0x00001000);
 			nv_mask(dev, 0x10f804, 0x80000000, 0x00000000);
+			nv_mask(dev, 0x100760, 0x22222222, info->r100760);
+			nv_mask(dev, 0x1007a0, 0x22222222, info->r100760);
+			nv_mask(dev, 0x1007e0, 0x22222222, info->r100760);
 		}
 	}
 
@@ -480,6 +485,12 @@ prog_mem(struct drm_device *dev, struct nva3_pm_state *info)
 	};
 	u32 ctrl;
 
+	/* XXX: where the fuck does 750MHz come from? */
+	if (info->perflvl->memory <= 750000) {
+		info->r004018 = 0x10000000;
+		info->r100760 = 0x22222222;
+	}
+
 	ctrl = nv_rd32(dev, 0x004000);
 	if (ctrl & 0x00000008) {
 		if (info->mclk.pll) {
@@ -489,7 +500,7 @@ prog_mem(struct drm_device *dev, struct nva3_pm_state *info)
 			nv_wr32(dev, 0x004000, (ctrl &= 0xffffffef));
 			nv_wait(dev, 0x004000, 0x00020000, 0x00020000);
 			nv_wr32(dev, 0x004000, (ctrl |= 0x00000010));
-			nv_wr32(dev, 0x004018, 0x00005000); /*XXX*/
+			nv_wr32(dev, 0x004018, 0x00005000 | info->r004018);
 			nv_wr32(dev, 0x004000, (ctrl |= 0x00000004));
 		}
 	} else {