drm/nouveau/hwmon: add in_min and in_max

it is a little help for hardware monitoring tools
Signed-off-by: Karol Herbst <karolherbst@gmail.de>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_hwmon.c

@@ -534,6 +534,40 @@ nouveau_hwmon_get_in0_input(struct device *d,
 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO,
 			  nouveau_hwmon_get_in0_input, NULL, 0);
 
+static ssize_t
+nouveau_hwmon_get_in0_min(struct device *d,
+			    struct device_attribute *a, char *buf)
+{
+	struct drm_device *dev = dev_get_drvdata(d);
+	struct nouveau_drm *drm = nouveau_drm(dev);
+	struct nvkm_volt *volt = nvxx_volt(&drm->device);
+
+	if (!volt || !volt->min_uv)
+		return -ENODEV;
+
+	return sprintf(buf, "%i\n", volt->min_uv / 1000);
+}
+
+static SENSOR_DEVICE_ATTR(in0_min, S_IRUGO,
+			  nouveau_hwmon_get_in0_min, NULL, 0);
+
+static ssize_t
+nouveau_hwmon_get_in0_max(struct device *d,
+			    struct device_attribute *a, char *buf)
+{
+	struct drm_device *dev = dev_get_drvdata(d);
+	struct nouveau_drm *drm = nouveau_drm(dev);
+	struct nvkm_volt *volt = nvxx_volt(&drm->device);
+
+	if (!volt || !volt->max_uv)
+		return -ENODEV;
+
+	return sprintf(buf, "%i\n", volt->max_uv / 1000);
+}
+
+static SENSOR_DEVICE_ATTR(in0_max, S_IRUGO,
+			  nouveau_hwmon_get_in0_max, NULL, 0);
+
 static ssize_t
 nouveau_hwmon_get_in0_label(struct device *d,
 			    struct device_attribute *a, char *buf)
@@ -594,6 +628,8 @@ static struct attribute *hwmon_pwm_fan_attributes[] = {
 
 static struct attribute *hwmon_in0_attributes[] = {
 	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in0_min.dev_attr.attr,
+	&sensor_dev_attr_in0_max.dev_attr.attr,
 	&sensor_dev_attr_in0_label.dev_attr.attr,
 	NULL
 };