--- /root/nouveau_backlight.c.orig	2016-08-04 20:59:42.590183002 -0400
+++ drivers/gpu/drm/nouveau/nouveau_backlight.c	2016-08-16 09:59:06.227494781 -0400
@@ -35,6 +35,86 @@
 #include "nouveau_drm.h"
 #include "nouveau_reg.h"
 #include "nouveau_encoder.h"
+#include "nvif/device.h"
+#include "nvkm/subdev/bios/gpio.h"
+
+#define NV30_BL_MIN_LEVEL 0x16d
+#define NV30_BL_MAX_LEVEL 0x534
+
+static int
+nv30_get_intensity(struct backlight_device *bd)
+{
+	struct nouveau_drm *drm = bl_get_data(bd);
+	struct nvif_object *device = &drm->device.object;
+	int val = (nvif_rd32(device,
+			     NV30_PMC_BACKLIGHT) &
+                             NV30_PMC_BACKLIGHT_MASK) >> 16;
+	if (val == 0x00)
+		return 0;
+
+	return val - NV30_BL_MIN_LEVEL + 1;
+}
+
+static int
+nv30_set_intensity(struct backlight_device *bd)
+{
+	struct nouveau_drm *drm = bl_get_data(bd);
+	struct nvif_object *device = &drm->device.object;
+	int val = bd->props.brightness;
+	int level;
+	if (val == 0)
+		level = 0x00;
+	else
+		level = val + NV30_BL_MIN_LEVEL - 1;
+	nvif_wr32(device,
+		  NV30_PMC_BACKLIGHT,
+		  ((level << 16) + 0x535) | 0x80000000);
+	/* workaround for disabled backlight after waking from suspend */
+
+	return 0;
+}
+
+static const struct backlight_ops nv30_bl_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.get_brightness = nv30_get_intensity,
+	.update_status = nv30_set_intensity,
+};
+
+static int
+nv30_backlight_init(struct drm_connector *connector)
+{
+	struct nouveau_drm *drm = nouveau_drm(connector->dev);
+	struct nvif_object *device = &drm->device.object;
+	struct backlight_properties props;
+	struct backlight_device *bd;
+	struct dcb_gpio_func func;
+	struct nvkm_gpio *gpio = nvxx_gpio(&drm->device);
+	int ret;
+	ret = nvkm_gpio_find(gpio, 0, 0x00, 0xff, &func);
+	if (ret != 0)
+		return 0;
+
+	if (!(nvif_rd32(device, NV30_PMC_BACKLIGHT) & NV30_PMC_BACKLIGHT_MASK))
+		return 0;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = NV30_BL_MAX_LEVEL - NV30_BL_MIN_LEVEL;  
+	/* includes an additional 0x00 level (backlight off) */
+
+	bd = backlight_device_register("nv_backlight",
+				       connector->kdev,
+				       drm,
+                                       &nv30_bl_ops,
+				       &props);
+	if (IS_ERR(bd))
+		return PTR_ERR(bd);
+	drm->backlight = bd;
+	bd->props.brightness = nv30_get_intensity(bd);
+	backlight_update_status(bd);
+
+	return 0;
+}
 
 static int
 nv40_get_intensity(struct backlight_device *bd)
@@ -227,6 +307,8 @@
 			continue;
 
 		switch (device->info.family) {
+                case NV_DEVICE_INFO_V0_RANKINE:
+                        return nv30_backlight_init(connector);
 		case NV_DEVICE_INFO_V0_CURIE:
 			return nv40_backlight_init(connector);
 		case NV_DEVICE_INFO_V0_TESLA: