drm/rockchip: vop: split out core clock enablement into separate functions

Judging from the iommu code, both the hclk and aclk are necessary for
register access. Split them off into separate functions from the regular
vop enablement, so that we can use them elsewhere as well.

Fixes: d0b912bd ("iommu/rockchip: Request irqs in rk_iommu_probe()")
[prerequisite change for the actual fix]
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180612132028.27490-2-heiko@sntech.de

drivers/gpu/drm/rockchip/rockchip_drm_vop.c

@@ -486,6 +486,31 @@ static void vop_line_flag_irq_disable(struct vop *vop)
 	spin_unlock_irqrestore(&vop->irq_lock, flags);
 }
 
+static int vop_core_clks_enable(struct vop *vop)
+{
+	int ret;
+
+	ret = clk_enable(vop->hclk);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_enable(vop->aclk);
+	if (ret < 0)
+		goto err_disable_hclk;
+
+	return 0;
+
+err_disable_hclk:
+	clk_disable(vop->hclk);
+	return ret;
+}
+
+static void vop_core_clks_disable(struct vop *vop)
+{
+	clk_disable(vop->aclk);
+	clk_disable(vop->hclk);
+}
+
 static int vop_enable(struct drm_crtc *crtc)
 {
 	struct vop *vop = to_vop(crtc);
@@ -497,17 +522,13 @@ static int vop_enable(struct drm_crtc *crtc)
 		return ret;
 	}
 
-	ret = clk_enable(vop->hclk);
+	ret = vop_core_clks_enable(vop);
 	if (WARN_ON(ret < 0))
 		goto err_put_pm_runtime;
 
 	ret = clk_enable(vop->dclk);
 	if (WARN_ON(ret < 0))
-		goto err_disable_hclk;
-
-	ret = clk_enable(vop->aclk);
-	if (WARN_ON(ret < 0))
-		goto err_disable_dclk;
+		goto err_disable_core;
 
 	/*
 	 * Slave iommu shares power, irq and clock with vop.  It was associated
@@ -519,7 +540,7 @@ static int vop_enable(struct drm_crtc *crtc)
 	if (ret) {
 		DRM_DEV_ERROR(vop->dev,
 			      "failed to attach dma mapping, %d\n", ret);
-		goto err_disable_aclk;
+		goto err_disable_dclk;
 	}
 
 	spin_lock(&vop->reg_lock);
@@ -558,12 +579,10 @@ static int vop_enable(struct drm_crtc *crtc)
 
 	return 0;
 
-err_disable_aclk:
-	clk_disable(vop->aclk);
 err_disable_dclk:
 	clk_disable(vop->dclk);
-err_disable_hclk:
-	clk_disable(vop->hclk);
+err_disable_core:
+	vop_core_clks_disable(vop);
 err_put_pm_runtime:
 	pm_runtime_put_sync(vop->dev);
 	return ret;
@@ -609,8 +628,7 @@ static void vop_crtc_atomic_disable(struct drm_crtc *crtc,
 	rockchip_drm_dma_detach_device(vop->drm_dev, vop->dev);
 
 	clk_disable(vop->dclk);
-	clk_disable(vop->aclk);
-	clk_disable(vop->hclk);
+	vop_core_clks_disable(vop);
 	pm_runtime_put(vop->dev);
 	mutex_unlock(&vop->vop_lock);