4 files changed, 40 insertions, 2 deletions

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index e714709704e4..5b47210889e0 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -13,6 +13,7 @@
 #include <linux/string.h>
 #include <linux/platform_device.h>
 #include <linux/of_device.h>
+#include <linux/of_irq.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/dma-mapping.h>
@@ -87,7 +88,11 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
                 return -ENXIO;
         return dev->archdata.irqs[num];
 #else
-        struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
+        struct resource *r;
+        if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node)
+                return of_irq_get(dev->dev.of_node, num);
+
+        r = platform_get_resource(dev, IORESOURCE_IRQ, num);
 
         return r ? r->start : -ENXIO;
 #endif
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index e2e4c548a42f..5aeb89411350 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -380,6 +380,32 @@ int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
 EXPORT_SYMBOL_GPL(of_irq_to_resource);
 
 /**
+ * of_irq_get - Decode a node's IRQ and return it as a Linux irq number
+ * @dev: pointer to device tree node
+ * @index: zero-based index of the irq
+ *
+ * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
+ * is not yet created.
+ *
+ */
+int of_irq_get(struct device_node *dev, int index)
+{
+        int rc;
+        struct of_phandle_args oirq;
+        struct irq_domain *domain;
+
+        rc = of_irq_parse_one(dev, index, &oirq);
+        if (rc)
+                return rc;
+
+        domain = irq_find_host(oirq.np);
+        if (!domain)
+                return -EPROBE_DEFER;
+
+        return irq_create_of_mapping(&oirq);
+}
+
+/**
  * of_irq_count - Count the number of IRQs a node uses
  * @dev: pointer to device tree node
  */
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 404d1daebefa..bd47fbc53dc9 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -168,7 +168,9 @@ struct platform_device *of_device_alloc(struct device_node *np,
                         rc = of_address_to_resource(np, i, res);
                         WARN_ON(rc);
                 }
-                WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
+                if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
+                        pr_debug("not all legacy IRQ resources mapped for %s\n",
+                                 np->name);
         }
 
         dev->dev.of_node = of_node_get(np);
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 3f23b4472c31..6404253d810d 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -44,11 +44,16 @@ extern void of_irq_init(const struct of_device_id *matches);
 
 #ifdef CONFIG_OF_IRQ
 extern int of_irq_count(struct device_node *dev);
+extern int of_irq_get(struct device_node *dev, int index);
 #else
 static inline int of_irq_count(struct device_node *dev)
 {
         return 0;
 }
+static inline int of_irq_get(struct device_node *dev, int index)
+{
+        return 0;
+}
 #endif
 
 #if defined(CONFIG_OF)