[PATCH v4 07/10] drm: rcar-du: Provide for_each_group helper

[Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>]

Refactoring of the group control code will soon require more iteration
over the available groups. Simplify this process by introducing a group
iteration helper.

Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
Changes since v2:

- Don't assign __group in the condition part of the for statement of the
  for_each_rcdu_group() macro

 drivers/gpu/drm/rcar-du/rcar_du_drv.h |  5 +++++
 drivers/gpu/drm/rcar-du/rcar_du_kms.c | 10 ++--------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.h b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
index 02ca2d0e1b55..e792ba7f5145 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.h
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.h
@@ -104,6 +104,11 @@ static inline struct rcar_du_device *to_rcar_du_device(struct drm_device *dev)
 	return container_of(dev, struct rcar_du_device, ddev);
 }
 
+#define for_each_rcdu_group(__rcdu, __group, __i) \
+	for ((__i) = 0, (__group) = &(__rcdu)->groups[0]; \
+	     (__i) < DIV_ROUND_UP((__rcdu)->num_crtcs, 2); \
+	     __i++, __group++)
+
 static inline bool rcar_du_has(struct rcar_du_device *rcdu,
 			       unsigned int feature)
 {
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index 3c10c329c81c..732aac342dab 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -771,9 +771,9 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 
 	struct drm_device *dev = &rcdu->ddev;
 	struct drm_encoder *encoder;
+	struct rcar_du_group *rgrp;
 	unsigned int dpad0_sources;
 	unsigned int num_encoders;
-	unsigned int num_groups;
 	unsigned int swindex;
 	unsigned int hwindex;
 	unsigned int i;
@@ -820,11 +820,7 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 		return ret;
 
 	/* Initialize the groups. */
-	num_groups = DIV_ROUND_UP(rcdu->num_crtcs, 2);
-
-	for (i = 0; i < num_groups; ++i) {
-		struct rcar_du_group *rgrp = &rcdu->groups[i];
-
+	for_each_rcdu_group(rcdu, rgrp, i) {
 		mutex_init(&rgrp->lock);
 
 		rgrp->dev = rcdu;
@@ -866,8 +862,6 @@ int rcar_du_modeset_init(struct rcar_du_device *rcdu)
 
 	/* Create the CRTCs. */
 	for (swindex = 0, hwindex = 0; swindex < rcdu->num_crtcs; ++hwindex) {
-		struct rcar_du_group *rgrp;
-
 		/* Skip unpopulated DU channels. */
 		if (!(rcdu->info->channels_mask & BIT(hwindex)))
 			continue;
-- 
2.25.1