[PATCH v6 06/11] devm-helpers: Add resource managed version of irq_create_mapping()

["Marek Behún" <kabel@kernel.org>]

Add resource managed version of irq_create_mapping(), to help drivers
automatically dispose a linux irq mapping when driver is detached.

Signed-off-by: Marek Behún <kabel@kernel.org>
---
 include/linux/devm-helpers.h | 54 ++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/include/linux/devm-helpers.h b/include/linux/devm-helpers.h
index 74891802200d..fe62b28baf03 100644
--- a/include/linux/devm-helpers.h
+++ b/include/linux/devm-helpers.h
@@ -24,6 +24,8 @@
  */
 
 #include <linux/device.h>
+#include <linux/kconfig.h>
+#include <linux/irqdomain.h>
 #include <linux/workqueue.h>
 
 static inline void devm_delayed_work_drop(void *res)
@@ -76,4 +78,56 @@ static inline int devm_work_autocancel(struct device *dev,
 	return devm_add_action(dev, devm_work_drop, w);
 }
 
+/**
+ * devm_irq_mapping_drop - devm action for disposing an irq mapping
+ * @res:	linux irq number cast to the void * type
+ *
+ * devm_irq_mapping_drop() can be used as an action parameter for the
+ * devm_add_action_or_reset() function in order to automatically dispose
+ * a linux irq mapping when a device driver is detached.
+ */
+static inline void devm_irq_mapping_drop(void *res)
+{
+	irq_dispose_mapping((unsigned int)(unsigned long)res);
+}
+
+/**
+ * devm_irq_create_mapping - Resource managed version of irq_create_mapping()
+ * @dev:	Device which lifetime the mapping is bound to
+ * @domain:	domain owning this hardware interrupt or NULL for default domain
+ * @hwirq:	hardware irq number in that domain space
+ *
+ * Create an irq mapping to linux irq space which is automatically disposed when
+ * the driver is detached.
+ * devm_irq_create_mapping() can be used to omit the explicit
+ * irq_dispose_mapping() call when driver is detached.
+ *
+ * Returns a linux irq number on success, -ENXIO if the mapping could not be
+ * created, or a negative error number if devm action could not be added.
+ */
+static inline int devm_irq_create_mapping(struct device *dev,
+					  struct irq_domain *domain,
+					  irq_hw_number_t hwirq)
+{
+	unsigned int virq = irq_create_mapping(domain, hwirq);
+
+	if (!virq)
+		return -ENXIO;
+
+	/*
+	 * irq_dispose_mapping() is an empty function if CONFIG_IRQ_DOMAIN is
+	 * disabled. No need to register an action in that case.
+	 */
+	if (IS_ENABLED(CONFIG_IRQ_DOMAIN)) {
+		int err;
+
+		err = devm_add_action_or_reset(dev, devm_irq_mapping_drop,
+					       (void *)(unsigned long)virq);
+		if (err)
+			return err;
+	}
+
+	return virq;
+}
+
 #endif
-- 
2.43.2