drm: Add drm_encoder_mask()

Add drm_encoder_mask() which returns the 1<<index for the encoder.
We already have an identical drm_crtc_mask() for crtcs.

Mostly performed with coccinelle:
@@
@@
- (1<<drm_encoder_index(
+ drm_encoder_mask(
  ...)
-  )

@@
@@
- 1<<drm_encoder_index(
+ drm_encoder_mask(
  ...)

@@
@@
- BIT(drm_encoder_index(
+ drm_encoder_mask(
  ...)
- )

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180626194716.12522-3-ville.syrjala@linux.intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/drm_atomic_helper.c

@@ -121,7 +121,7 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
 			new_encoder = drm_atomic_helper_best_encoder(connector);
 
 		if (new_encoder) {
-			if (encoder_mask & (1 << drm_encoder_index(new_encoder))) {
+			if (encoder_mask & drm_encoder_mask(new_encoder)) {
 				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] on [CONNECTOR:%d:%s] already assigned\n",
 					new_encoder->base.id, new_encoder->name,
 					connector->base.id, connector->name);
@@ -129,7 +129,7 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
 				return -EINVAL;
 			}
 
-			encoder_mask |= 1 << drm_encoder_index(new_encoder);
+			encoder_mask |= drm_encoder_mask(new_encoder);
 		}
 	}
 
@@ -155,7 +155,7 @@ static int handle_conflicting_encoders(struct drm_atomic_state *state,
 			continue;
 
 		encoder = connector->state->best_encoder;
-		if (!encoder || !(encoder_mask & (1 << drm_encoder_index(encoder))))
+		if (!encoder || !(encoder_mask & drm_encoder_mask(encoder)))
 			continue;
 
 		if (!disable_conflicting_encoders) {
@@ -223,7 +223,7 @@ set_best_encoder(struct drm_atomic_state *state,
 			crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 
 			crtc_state->encoder_mask &=
-				~(1 << drm_encoder_index(conn_state->best_encoder));
+				~drm_encoder_mask(conn_state->best_encoder);
 		}
 	}
 
@@ -234,7 +234,7 @@ set_best_encoder(struct drm_atomic_state *state,
 			crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 
 			crtc_state->encoder_mask |=
-				1 << drm_encoder_index(encoder);
+				drm_encoder_mask(encoder);
 		}
 	}
 

include/drm/drm_encoder.h

@@ -191,11 +191,23 @@ int drm_encoder_init(struct drm_device *dev,
  * Given a registered encoder, return the index of that encoder within a DRM
  * device's list of encoders.
  */
-static inline unsigned int drm_encoder_index(struct drm_encoder *encoder)
+static inline unsigned int drm_encoder_index(const struct drm_encoder *encoder)
 {
 	return encoder->index;
 }
 
+/**
+ * drm_encoder_mask - find the mask of a registered ENCODER
+ * @encoder: encoder to find mask for
+ *
+ * Given a registered encoder, return the mask bit of that encoder for an
+ * encoder's possible_clones field.
+ */
+static inline u32 drm_encoder_mask(const struct drm_encoder *encoder)
+{
+	return 1 << drm_encoder_index(encoder);
+}
+
 /**
  * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
  * @encoder: encoder to test
@@ -241,7 +253,7 @@ void drm_encoder_cleanup(struct drm_encoder *encoder);
  */
 #define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
 	list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
-		for_each_if ((encoder_mask) & (1 << drm_encoder_index(encoder)))
+		for_each_if ((encoder_mask) & drm_encoder_mask(encoder))
 
 /**
  * drm_for_each_encoder - iterate over all encoders