genirq: introduce irq_domain_translate_twocell

Add a new function irq_domain_translate_twocell() that is to be used as
the translate function in struct irq_domain_ops for the v2 IRQ API.

This patch also changes irq_domain_xlate_twocell() from the v1 IRQ API
to call irq_domain_translate_twocell() in the v2 IRQ API. This required
changes to of_phandle_args_to_fwspec()'s arguments so that it can be
called from multiple places.

Cc: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/irqdomain.h

@@ -419,6 +419,11 @@ 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);
 
+int irq_domain_translate_twocell(struct irq_domain *d,
+				 struct irq_fwspec *fwspec,
+				 unsigned long *out_hwirq,
+				 unsigned int *out_type);
+
 /* IPI functions */
 int irq_reserve_ipi(struct irq_domain *domain, const struct cpumask *dest);
 int irq_destroy_ipi(unsigned int irq, const struct cpumask *dest);

kernel/irq/irqdomain.c

@@ -729,16 +729,17 @@ static int irq_domain_translate(struct irq_domain *d,
 	return 0;
 }
 
-static void of_phandle_args_to_fwspec(struct of_phandle_args *irq_data,
+static void of_phandle_args_to_fwspec(struct device_node *np, const u32 *args,
+				      unsigned int count,
 				      struct irq_fwspec *fwspec)
 {
 	int i;
 
-	fwspec->fwnode = irq_data->np ? &irq_data->np->fwnode : NULL;
-	fwspec->param_count = irq_data->args_count;
+	fwspec->fwnode = np ? &np->fwnode : NULL;
+	fwspec->param_count = count;
 
-	for (i = 0; i < irq_data->args_count; i++)
-		fwspec->param[i] = irq_data->args[i];
+	for (i = 0; i < count; i++)
+		fwspec->param[i] = args[i];
 }
 
 unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
@@ -836,7 +837,9 @@ unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
 {
 	struct irq_fwspec fwspec;
 
-	of_phandle_args_to_fwspec(irq_data, &fwspec);
+	of_phandle_args_to_fwspec(irq_data->np, irq_data->args,
+				  irq_data->args_count, &fwspec);
+
 	return irq_create_fwspec_mapping(&fwspec);
 }
 EXPORT_SYMBOL_GPL(irq_create_of_mapping);
@@ -928,11 +931,10 @@ 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)
 {
-	if (WARN_ON(intsize < 2))
-		return -EINVAL;
-	*out_hwirq = intspec[0];
-	*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
-	return 0;
+	struct irq_fwspec fwspec;
+
+	of_phandle_args_to_fwspec(ctrlr, intspec, intsize, &fwspec);
+	return irq_domain_translate_twocell(d, &fwspec, out_hwirq, out_type);
 }
 EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);
 
@@ -968,6 +970,27 @@ const struct irq_domain_ops irq_domain_simple_ops = {
 };
 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
 
+/**
+ * irq_domain_translate_twocell() - Generic translate for direct two cell
+ * bindings
+ *
+ * Device Tree IRQ specifier translation function which works with two cell
+ * bindings where the cell values map directly to the hwirq number
+ * and linux irq flags.
+ */
+int irq_domain_translate_twocell(struct irq_domain *d,
+				 struct irq_fwspec *fwspec,
+				 unsigned long *out_hwirq,
+				 unsigned int *out_type)
+{
+	if (WARN_ON(fwspec->param_count < 2))
+		return -EINVAL;
+	*out_hwirq = fwspec->param[0];
+	*out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_translate_twocell);
+
 int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
 			   int node, const struct irq_affinity_desc *affinity)
 {