irq_domain: Create common xlate functions that device drivers can use

Rather than having each interrupt controller driver creating its own barely
unique .xlate function for irq_domain, create a library of translators which
any driver can use directly.

v5: - Remove irq_domain_xlate_pci().  It was incorrect.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index e7379a3..ea58f36 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -163,6 +163,18 @@
 				      irq_hw_number_t hwirq);
 
 extern struct irq_domain_ops irq_domain_simple_ops;
+
+/* stock xlate functions */
+int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type);
+int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type);
+int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type);
+
 #if defined(CONFIG_OF_IRQ)
 extern void irq_domain_generate_simple(const struct of_device_id *match,
 					u64 phys_base, unsigned int irq_start);