drm/msm/mdp4: move resource allocation to the _probe function

To let the probe function bail early if any of the resources is
unavailable, move resource allocattion from kms_init directly to the
probe callback. While we are at it, replace irq_of_parse_and_map() with
platform_get_irq().

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/561628/
Signed-off-by: Rob Clark <robdclark@chromium.org>

Author: lumag

drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c

@@ -135,8 +135,6 @@ static void mdp4_destroy(struct msm_kms *kms)
 		pm_runtime_disable(dev);
 
 	mdp_kms_destroy(&mdp4_kms->base);
-
-	kfree(mdp4_kms);
 }
 
 static const struct mdp_kms_funcs kms_funcs = {
@@ -380,56 +378,27 @@ static int mdp4_kms_init(struct drm_device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev->dev);
 	struct msm_drm_private *priv = dev->dev_private;
-	struct mdp4_kms *mdp4_kms;
+	struct mdp4_kms *mdp4_kms = to_mdp4_kms(to_mdp_kms(priv->kms));
 	struct msm_kms *kms = NULL;
 	struct msm_mmu *mmu;
 	struct msm_gem_address_space *aspace;
-	int irq, ret;
+	int ret;
 	u32 major, minor;
 	unsigned long max_clk;
 
 	/* TODO: Chips that aren't apq8064 have a 200 Mhz max_clk */
 	max_clk = 266667000;
 
-	mdp4_kms = kzalloc(sizeof(*mdp4_kms), GFP_KERNEL);
-	if (!mdp4_kms) {
-		DRM_DEV_ERROR(dev->dev, "failed to allocate kms\n");
-		return -ENOMEM;
-	}
-
 	ret = mdp_kms_init(&mdp4_kms->base, &kms_funcs);
 	if (ret) {
 		DRM_DEV_ERROR(dev->dev, "failed to init kms\n");
 		goto fail;
 	}
 
-	priv->kms = &mdp4_kms->base.base;
 	kms = priv->kms;
 
 	mdp4_kms->dev = dev;
 
-	mdp4_kms->mmio = msm_ioremap(pdev, NULL);
-	if (IS_ERR(mdp4_kms->mmio)) {
-		ret = PTR_ERR(mdp4_kms->mmio);
-		goto fail;
-	}
-
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		ret = irq;
-		goto fail;
-	}
-
-	kms->irq = irq;
-
-	/* NOTE: driver for this regulator still missing upstream.. use
-	 * _get_exclusive() and ignore the error if it does not exist
-	 * (and hope that the bootloader left it on for us)
-	 */
-	mdp4_kms->vdd = devm_regulator_get_exclusive(&pdev->dev, "vdd");
-	if (IS_ERR(mdp4_kms->vdd))
-		mdp4_kms->vdd = NULL;
-
 	if (mdp4_kms->vdd) {
 		ret = regulator_enable(mdp4_kms->vdd);
 		if (ret) {
@@ -438,24 +407,6 @@ static int mdp4_kms_init(struct drm_device *dev)
 		}
 	}
 
-	mdp4_kms->clk = devm_clk_get(&pdev->dev, "core_clk");
-	if (IS_ERR(mdp4_kms->clk)) {
-		DRM_DEV_ERROR(dev->dev, "failed to get core_clk\n");
-		ret = PTR_ERR(mdp4_kms->clk);
-		goto fail;
-	}
-
-	mdp4_kms->pclk = devm_clk_get(&pdev->dev, "iface_clk");
-	if (IS_ERR(mdp4_kms->pclk))
-		mdp4_kms->pclk = NULL;
-
-	mdp4_kms->axi_clk = devm_clk_get(&pdev->dev, "bus_clk");
-	if (IS_ERR(mdp4_kms->axi_clk)) {
-		DRM_DEV_ERROR(dev->dev, "failed to get axi_clk\n");
-		ret = PTR_ERR(mdp4_kms->axi_clk);
-		goto fail;
-	}
-
 	clk_set_rate(mdp4_kms->clk, max_clk);
 
 	read_mdp_hw_revision(mdp4_kms, &major, &minor);
@@ -470,10 +421,9 @@ static int mdp4_kms_init(struct drm_device *dev)
 	mdp4_kms->rev = minor;
 
 	if (mdp4_kms->rev >= 2) {
-		mdp4_kms->lut_clk = devm_clk_get(&pdev->dev, "lut_clk");
-		if (IS_ERR(mdp4_kms->lut_clk)) {
+		if (!mdp4_kms->lut_clk) {
 			DRM_DEV_ERROR(dev->dev, "failed to get lut_clk\n");
-			ret = PTR_ERR(mdp4_kms->lut_clk);
+			ret = -ENODEV;
 			goto fail;
 		}
 		clk_set_rate(mdp4_kms->lut_clk, max_clk);
@@ -557,7 +507,53 @@ static const struct dev_pm_ops mdp4_pm_ops = {
 
 static int mdp4_probe(struct platform_device *pdev)
 {
-	return msm_drv_probe(&pdev->dev, mdp4_kms_init, NULL);
+	struct device *dev = &pdev->dev;
+	struct mdp4_kms *mdp4_kms;
+	int irq;
+
+	mdp4_kms = devm_kzalloc(dev, sizeof(*mdp4_kms), GFP_KERNEL);
+	if (!mdp4_kms)
+		return dev_err_probe(dev, -ENOMEM, "failed to allocate kms\n");
+
+	mdp4_kms->mmio = msm_ioremap(pdev, NULL);
+	if (IS_ERR(mdp4_kms->mmio))
+		return PTR_ERR(mdp4_kms->mmio);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return dev_err_probe(dev, irq, "failed to get irq\n");
+
+	mdp4_kms->base.base.irq = irq;
+
+	/* NOTE: driver for this regulator still missing upstream.. use
+	 * _get_exclusive() and ignore the error if it does not exist
+	 * (and hope that the bootloader left it on for us)
+	 */
+	mdp4_kms->vdd = devm_regulator_get_exclusive(&pdev->dev, "vdd");
+	if (IS_ERR(mdp4_kms->vdd))
+		mdp4_kms->vdd = NULL;
+
+	mdp4_kms->clk = devm_clk_get(&pdev->dev, "core_clk");
+	if (IS_ERR(mdp4_kms->clk))
+		return dev_err_probe(dev, PTR_ERR(mdp4_kms->clk), "failed to get core_clk\n");
+
+	mdp4_kms->pclk = devm_clk_get(&pdev->dev, "iface_clk");
+	if (IS_ERR(mdp4_kms->pclk))
+		mdp4_kms->pclk = NULL;
+
+	mdp4_kms->axi_clk = devm_clk_get(&pdev->dev, "bus_clk");
+	if (IS_ERR(mdp4_kms->axi_clk))
+		return dev_err_probe(dev, PTR_ERR(mdp4_kms->axi_clk), "failed to get axi_clk\n");
+
+	/*
+	 * This is required for revn >= 2. Handle errors here and let the kms
+	 * init bail out if the clock is not provided.
+	 */
+	mdp4_kms->lut_clk = devm_clk_get_optional(&pdev->dev, "lut_clk");
+	if (IS_ERR(mdp4_kms->lut_clk))
+		return dev_err_probe(dev, PTR_ERR(mdp4_kms->lut_clk), "failed to get lut_clk\n");
+
+	return msm_drv_probe(&pdev->dev, mdp4_kms_init, &mdp4_kms->base.base);
 }
 
 static int mdp4_remove(struct platform_device *pdev)