iommu/rockchip: Don't use platform_get_irq to implicitly count irqs

Till now the Rockchip iommu driver walked through the irq list via
platform_get_irq() until it encountered an ENXIO error. With the
recent change to add a central error message, this always results
in such an error for each iommu on probe and shutdown.

To not confuse people, switch to platform_count_irqs() to get the
actual number of interrupts before walking through them.

Fixes: 7723f4c5 ("driver core: platform: Add an error message to platform_get_irq*()")
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/rockchip-iommu.c

@@ -100,6 +100,7 @@ struct rk_iommu {
 	struct device *dev;
 	void __iomem **bases;
 	int num_mmu;
+	int num_irq;
 	struct clk_bulk_data *clocks;
 	int num_clocks;
 	bool reset_disabled;
@@ -1136,7 +1137,7 @@ static int rk_iommu_probe(struct platform_device *pdev)
 	struct rk_iommu *iommu;
 	struct resource *res;
 	int num_res = pdev->num_resources;
-	int err, i, irq;
+	int err, i;
 
 	iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
 	if (!iommu)
@@ -1163,6 +1164,10 @@ static int rk_iommu_probe(struct platform_device *pdev)
 	if (iommu->num_mmu == 0)
 		return PTR_ERR(iommu->bases[0]);
 
+	iommu->num_irq = platform_irq_count(pdev);
+	if (iommu->num_irq < 0)
+		return iommu->num_irq;
+
 	iommu->reset_disabled = device_property_read_bool(dev,
 					"rockchip,disable-mmu-reset");
 
@@ -1219,8 +1224,9 @@ static int rk_iommu_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(dev);
 
-	i = 0;
-	while ((irq = platform_get_irq(pdev, i++)) != -ENXIO) {
+	for (i = 0; i < iommu->num_irq; i++) {
+		int irq = platform_get_irq(pdev, i);
+
 		if (irq < 0)
 			return irq;
 
@@ -1245,10 +1251,13 @@ static int rk_iommu_probe(struct platform_device *pdev)
 static void rk_iommu_shutdown(struct platform_device *pdev)
 {
 	struct rk_iommu *iommu = platform_get_drvdata(pdev);
-	int i = 0, irq;
+	int i;
+
+	for (i = 0; i < iommu->num_irq; i++) {
+		int irq = platform_get_irq(pdev, i);
 
-	while ((irq = platform_get_irq(pdev, i++)) != -ENXIO)
 		devm_free_irq(iommu->dev, irq, iommu);
+	}
 
 	pm_runtime_force_suspend(&pdev->dev);
 }