fsl/fman: Use platform_get_irq() to get the interrupt

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq(). While doing so return error pointer
from read_dts_node() as platform_get_irq() may return -EPROBE_DEFER.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fman/fman.c

@@ -2727,7 +2727,7 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 
 	fman = kzalloc(sizeof(*fman), GFP_KERNEL);
 	if (!fman)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	fm_node = of_node_get(of_dev->dev.of_node);
 
@@ -2740,26 +2740,21 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 	fman->dts_params.id = (u8)val;
 
 	/* Get the FM interrupt */
-	res = platform_get_resource(of_dev, IORESOURCE_IRQ, 0);
-	if (!res) {
-		dev_err(&of_dev->dev, "%s: Can't get FMan IRQ resource\n",
-			__func__);
+	err = platform_get_irq(of_dev, 0);
+	if (err < 0)
 		goto fman_node_put;
-	}
-	irq = res->start;
+	irq = err;
 
 	/* Get the FM error interrupt */
-	res = platform_get_resource(of_dev, IORESOURCE_IRQ, 1);
-	if (!res) {
-		dev_err(&of_dev->dev, "%s: Can't get FMan Error IRQ resource\n",
-			__func__);
+	err = platform_get_irq(of_dev, 1);
+	if (err < 0)
 		goto fman_node_put;
-	}
-	fman->dts_params.err_irq = res->start;
+	fman->dts_params.err_irq = err;
 
 	/* Get the FM address */
 	res = platform_get_resource(of_dev, IORESOURCE_MEM, 0);
 	if (!res) {
+		err = -EINVAL;
 		dev_err(&of_dev->dev, "%s: Can't get FMan memory resource\n",
 			__func__);
 		goto fman_node_put;
@@ -2770,6 +2765,7 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 
 	clk = of_clk_get(fm_node, 0);
 	if (IS_ERR(clk)) {
+		err = PTR_ERR(clk);
 		dev_err(&of_dev->dev, "%s: Failed to get FM%d clock structure\n",
 			__func__, fman->dts_params.id);
 		goto fman_node_put;
@@ -2777,6 +2773,7 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 
 	clk_rate = clk_get_rate(clk);
 	if (!clk_rate) {
+		err = -EINVAL;
 		dev_err(&of_dev->dev, "%s: Failed to determine FM%d clock rate\n",
 			__func__, fman->dts_params.id);
 		goto fman_node_put;
@@ -2797,6 +2794,7 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 	/* Get the MURAM base address and size */
 	muram_node = of_find_matching_node(fm_node, fman_muram_match);
 	if (!muram_node) {
+		err = -EINVAL;
 		dev_err(&of_dev->dev, "%s: could not find MURAM node\n",
 			__func__);
 		goto fman_free;
@@ -2836,6 +2834,7 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 		devm_request_mem_region(&of_dev->dev, phys_base_addr,
 					mem_size, "fman");
 	if (!fman->dts_params.res) {
+		err = -EBUSY;
 		dev_err(&of_dev->dev, "%s: request_mem_region() failed\n",
 			__func__);
 		goto fman_free;
@@ -2844,6 +2843,7 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 	fman->dts_params.base_addr =
 		devm_ioremap(&of_dev->dev, phys_base_addr, mem_size);
 	if (!fman->dts_params.base_addr) {
+		err = -ENOMEM;
 		dev_err(&of_dev->dev, "%s: devm_ioremap() failed\n", __func__);
 		goto fman_free;
 	}
@@ -2868,7 +2868,7 @@ static struct fman *read_dts_node(struct platform_device *of_dev)
 	of_node_put(fm_node);
 fman_free:
 	kfree(fman);
-	return NULL;
+	return ERR_PTR(err);
 }
 
 static int fman_probe(struct platform_device *of_dev)
@@ -2880,8 +2880,8 @@ static int fman_probe(struct platform_device *of_dev)
 	dev = &of_dev->dev;
 
 	fman = read_dts_node(of_dev);
-	if (!fman)
-		return -EIO;
+	if (IS_ERR(fman))
+		return PTR_ERR(fman);
 
 	err = fman_config(fman);
 	if (err) {