[PATCH v3 1/2] of: irq: Added of_find_irq_domain() to get the domain of an irq

[Jean-Jacques Hiblot]

This functions does the same parsing as irq_of_parse_and_map but instead
of doing the mapping, it returns a pointer to the irq domain

Signed-off-by: Jean-Jacques Hiblot <jjhiblot at traphandler.com>
---
 drivers/of/irq.c       | 20 ++++++++++++++++++++
 include/linux/of_irq.h |  2 ++
 2 files changed, 22 insertions(+)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 9bcf2cf..7d3184f 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -46,6 +46,26 @@ unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
 EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
 
 /**
+ * of_find_irq_domain - Parse the DT and returns a pointer to the irq domain
+ * @dev: Device node of the device whose interrupt is concerned
+ * @index: Index of the interrupt to get the domain for
+ *
+ * This function is a wrapper that chains of_irq_parse_one() and
+ * irq_find_host() to make things easier to callers
+ */
+struct irq_domain *of_find_irq_domain(struct device_node *dev, int index)
+{
+	int rc;
+	struct of_phandle_args oirq;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return ERR_PTR(rc);
+
+	return irq_find_host(oirq.np);
+}
+
+/**
  * of_irq_find_parent - Given a device node, find its interrupt parent node
  * @child: pointer to device node
  *
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 3f23b44..600ff0a 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -58,6 +58,8 @@ static inline int of_irq_count(struct device_node *dev)
  * so declare it here regardless of the CONFIG_OF_IRQ setting.
  */
 extern unsigned int irq_of_parse_and_map(struct device_node *node, int index);
+extern struct irq_domain *of_find_irq_domain(struct device_node *dev,
+					     int index);
 extern struct device_node *of_irq_find_parent(struct device_node *child);
 
 #else /* !CONFIG_OF */
-- 
1.9.0