drm: kirin: use crtc helper drm_crtc_from_index()

Use drm_crtc_from_index() to find drm_crtc for given index, so that we
do not need to maintain a pointer array in struct kirin_drm_private.

Reviewed-by: Xinliang Liu<z.liuxinliang@hisilicon.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1483961145-18453-3-git-send-email-shawnguo@kernel.org

drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c

@@ -304,8 +304,8 @@ static void ade_set_medianoc_qos(struct ade_crtc *acrtc)
 
 static int ade_enable_vblank(struct drm_device *dev, unsigned int pipe)
 {
-	struct kirin_drm_private *priv = dev->dev_private;
-	struct ade_crtc *acrtc = to_ade_crtc(priv->crtc[pipe]);
+	struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+	struct ade_crtc *acrtc = to_ade_crtc(crtc);
 	struct ade_hw_ctx *ctx = acrtc->ctx;
 	void __iomem *base = ctx->base;
 
@@ -320,8 +320,8 @@ static int ade_enable_vblank(struct drm_device *dev, unsigned int pipe)
 
 static void ade_disable_vblank(struct drm_device *dev, unsigned int pipe)
 {
-	struct kirin_drm_private *priv = dev->dev_private;
-	struct ade_crtc *acrtc = to_ade_crtc(priv->crtc[pipe]);
+	struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+	struct ade_crtc *acrtc = to_ade_crtc(crtc);
 	struct ade_hw_ctx *ctx = acrtc->ctx;
 	void __iomem *base = ctx->base;
 
@@ -575,7 +575,6 @@ static const struct drm_crtc_funcs ade_crtc_funcs = {
 static int ade_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 			 struct drm_plane *plane)
 {
-	struct kirin_drm_private *priv = dev->dev_private;
 	struct device_node *port;
 	int ret;
 
@@ -599,7 +598,6 @@ static int ade_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 	}
 
 	drm_crtc_helper_add(crtc, &ade_crtc_helper_funcs);
-	priv->crtc[drm_crtc_index(crtc)] = crtc;
 
 	return 0;
 }

drivers/gpu/drm/hisilicon/kirin/kirin_drm_drv.h

@@ -20,7 +20,6 @@ struct kirin_dc_ops {
 };
 
 struct kirin_drm_private {
-	struct drm_crtc *crtc[MAX_CRTC];
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 	struct drm_fbdev_cma *fbdev;
 #endif