drm: add signed-range property type

Like range, but values are signed.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>

drivers/gpu/drm/drm_crtc.c

@@ -3213,6 +3213,22 @@ struct drm_property *drm_property_create_bitmask(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_property_create_bitmask);
 
+static struct drm_property *property_create_range(struct drm_device *dev,
+					 int flags, const char *name,
+					 uint64_t min, uint64_t max)
+{
+	struct drm_property *property;
+
+	property = drm_property_create(dev, flags, name, 2);
+	if (!property)
+		return NULL;
+
+	property->values[0] = min;
+	property->values[1] = max;
+
+	return property;
+}
+
 /**
  * drm_property_create - create a new ranged property type
  * @dev: drm device
@@ -3235,21 +3251,20 @@ struct drm_property *drm_property_create_range(struct drm_device *dev, int flags
 					 const char *name,
 					 uint64_t min, uint64_t max)
 {
-	struct drm_property *property;
-
-	flags |= DRM_MODE_PROP_RANGE;
-
-	property = drm_property_create(dev, flags, name, 2);
-	if (!property)
-		return NULL;
-
-	property->values[0] = min;
-	property->values[1] = max;
-
-	return property;
+	return property_create_range(dev, DRM_MODE_PROP_RANGE | flags,
+			name, min, max);
 }
 EXPORT_SYMBOL(drm_property_create_range);
 
+struct drm_property *drm_property_create_signed_range(struct drm_device *dev,
+					 int flags, const char *name,
+					 int64_t min, int64_t max)
+{
+	return property_create_range(dev, DRM_MODE_PROP_SIGNED_RANGE | flags,
+			name, I642U64(min), I642U64(max));
+}
+EXPORT_SYMBOL(drm_property_create_signed_range);
+
 struct drm_property *drm_property_create_object(struct drm_device *dev,
 					 int flags, const char *name, uint32_t type)
 {
@@ -3685,6 +3700,12 @@ static bool drm_property_change_is_valid(struct drm_property *property,
 		if (value < property->values[0] || value > property->values[1])
 			return false;
 		return true;
+	} else if (drm_property_type_is(property, DRM_MODE_PROP_SIGNED_RANGE)) {
+		int64_t svalue = U642I64(value);
+		if (svalue < U642I64(property->values[0]) ||
+				svalue > U642I64(property->values[1]))
+			return false;
+		return true;
 	} else if (drm_property_type_is(property, DRM_MODE_PROP_BITMASK)) {
 		int i;
 		uint64_t valid_mask = 0;

include/drm/drm_crtc.h

@@ -65,6 +65,15 @@ struct drm_object_properties {
 	uint64_t values[DRM_OBJECT_MAX_PROPERTY];
 };
 
+static inline int64_t U642I64(uint64_t val)
+{
+	return (int64_t)*((int64_t *)&val);
+}
+static inline uint64_t I642U64(int64_t val)
+{
+	return (uint64_t)*((uint64_t *)&val);
+}
+
 enum drm_connector_force {
 	DRM_FORCE_UNSPECIFIED,
 	DRM_FORCE_OFF,
@@ -982,6 +991,9 @@ struct drm_property *drm_property_create_bitmask(struct drm_device *dev,
 struct drm_property *drm_property_create_range(struct drm_device *dev, int flags,
 					 const char *name,
 					 uint64_t min, uint64_t max);
+struct drm_property *drm_property_create_signed_range(struct drm_device *dev,
+					 int flags, const char *name,
+					 int64_t min, int64_t max);
 struct drm_property *drm_property_create_object(struct drm_device *dev,
 					 int flags, const char *name, uint32_t type);
 extern void drm_property_destroy(struct drm_device *dev, struct drm_property *property);

include/uapi/drm/drm_mode.h

@@ -265,6 +265,7 @@ struct drm_mode_get_connector {
 #define DRM_MODE_PROP_EXTENDED_TYPE	0x0000ffc0
 #define DRM_MODE_PROP_TYPE(n)		((n) << 6)
 #define DRM_MODE_PROP_OBJECT		DRM_MODE_PROP_TYPE(1)
+#define DRM_MODE_PROP_SIGNED_RANGE	DRM_MODE_PROP_TYPE(2)
 
 struct drm_mode_property_enum {
 	__u64 value;