Merge tag 'devicetree-for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux into next

Pull DeviceTree updates from Rob Herring:
 - Another round of clean-up of FDT related code in architecture code.
   This removes knowledge of internal FDT details from most
   architectures except powerpc.
 - Conversion of kernel's custom FDT parsing code to use libfdt.
 - DT based initialization for generic serial earlycon.  The
   introduction of generic serial earlycon support went in through the
   tty tree.
 - Improve the platform device naming for DT probed devices to ensure
   unique naming and use parent names instead of a global index.
 - Fix a race condition in of_update_property.
 - Unify the various linker section OF match tables and fix several
   function prototype errors.
 - Update platform_get_irq_byname to work in deferred probe cases.
 - 2 binding doc updates

* tag 'devicetree-for-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (58 commits)
  of: handle NULL node in next_child iterators
  of/irq: provide more wrappers for !CONFIG_OF
  devicetree: bindings: Document micrel vendor prefix
  dt: bindings: dwc2: fix required value for the phy-names property
  of_pci_irq: kill useless variable in of_irq_parse_pci()
  of/irq: do irq resolution in platform_get_irq_byname()
  of: Add a testcase for of_find_node_by_path()
  of: Make of_find_node_by_path() handle /aliases
  of: Create unlocked version of for_each_child_of_node()
  lib: add glibc style strchrnul() variant
  of: Handle memory@0 node on PPC32 only
  pci/of: Remove dead code
  of: fix race between search and remove in of_update_property()
  of: Use NULL for pointers
  of: Stop naming platform_device using dcr address
  of: Ensure unique names without sacrificing determinism
  tty/serial: pl011: add DT based earlycon support
  of/fdt: add FDT serial scanning for earlycon
  of/fdt: add FDT address translation support
  serial: earlycon: add DT support
  ...

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 5aeb8941135..3e06a699352 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -406,6 +406,28 @@ int of_irq_get(struct device_node *dev, int index)
 }
 
 /**
+ * of_irq_get_byname - Decode a node's IRQ and return it as a Linux irq number
+ * @dev: pointer to device tree node
+ * @name: irq name
+ *
+ * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
+ * is not yet created, or error code in case of any other failure.
+ */
+int of_irq_get_byname(struct device_node *dev, const char *name)
+{
+	int index;
+
+	if (unlikely(!name))
+		return -EINVAL;
+
+	index = of_property_match_string(dev, "interrupt-names", name);
+	if (index < 0)
+		return index;
+
+	return of_irq_get(dev, index);
+}
+
+/**
  * of_irq_count - Count the number of IRQs a node uses
  * @dev: pointer to device tree node
  */