[PATCH 2/7] irqchip/irq-realtek-rtl: Use helper for parent setup

[Markus Stockhausen]

With the upcoming commits the parent interrupt setup will be extended.
Relocate it into a separate helper. Although it still works only
for a single interrupt prepare the coding so it can be easily
extended with a loop for multi parent support. For this reduce the
line lengths so that the upcoming indentation still leaves the
width below 100 characters.

Signed-off-by: Markus Stockhausen <markus.stockhausen@xxxxxx>
---
 drivers/irqchip/irq-realtek-rtl.c | 60 +++++++++++++++++--------------
 1 file changed, 33 insertions(+), 27 deletions(-)

diff --git a/drivers/irqchip/irq-realtek-rtl.c b/drivers/irqchip/irq-realtek-rtl.c
index 2ae3be7fa633..3b4508ec7198 100644
--- a/drivers/irqchip/irq-realtek-rtl.c
+++ b/drivers/irqchip/irq-realtek-rtl.c
@@ -147,48 +147,35 @@ static void realtek_irq_dispatch(struct irq_desc *desc)
 	chained_irq_exit(chip, desc);
 }
 
-static int __init realtek_rtl_of_init(struct device_node *node, struct device_node *parent)
+static int __init realtek_setup_parents(struct device_node *node)
 {
+	int parent_irq, num_parents = of_irq_count(node);
 	struct of_phandle_args oirq;
 	struct irq_domain *domain;
-	int cpu, parent_irq;
 
-	for_each_present_cpu(cpu) {
-		realtek_ictl_base[cpu] = of_iomap(node, cpu);
-		if (!realtek_ictl_base[cpu])
-			return -ENXIO;
-
-		/* Disable all cascaded interrupts and clear routing */
-		for (unsigned int hw_irq = 0; hw_irq < RTL_ICTL_NUM_INPUTS; hw_irq++) {
-			disable_gimr(cpu, hw_irq);
-			write_irr(cpu, hw_irq, 0);
-		}
-	}
-
-	if (WARN_ON(!of_irq_count(node))) {
+	if (WARN_ON(!num_parents)) {
 		/*
-		 * If DT contains no parent interrupts, assume MIPS CPU IRQ 2
-		 * (HW0) is connected to the first output. This is the case for
-		 * all known hardware anyway. "interrupt-map" is deprecated, so
-		 * don't bother trying to parse that.
+		 * If DT contains no parent interrupts, assume MIPS IRQ 2 (HW0) is
+		 * connected to the first output. This is the case for all known hardware.
 		 */
-		oirq.np = of_find_compatible_node(NULL, NULL, "mti,cpu-interrupt-controller");
+		oirq.np = of_find_compatible_node(NULL, NULL,
+						  "mti,cpu-interrupt-controller");
+		if (!oirq.np)
+			return -EINVAL;
+
 		oirq.args_count = 1;
 		oirq.args[0] = 2;
-
 		parent_irq = irq_create_of_mapping(&oirq);
-
 		of_node_put(oirq.np);
 	} else {
 		parent_irq = of_irq_get(node, 0);
 	}
 
-	if (parent_irq < 0)
-		return parent_irq;
-	else if (!parent_irq)
-		return -ENODEV;
+	if (parent_irq <= 0)
+		return parent_irq ? parent_irq : -ENODEV;
 
-	domain = irq_domain_create_linear(of_fwnode_handle(node), RTL_ICTL_NUM_INPUTS, &irq_domain_ops, NULL);
+	domain = irq_domain_create_linear(of_fwnode_handle(node), RTL_ICTL_NUM_INPUTS,
+					  &irq_domain_ops, NULL);
 	if (!domain)
 		return -ENOMEM;
 
@@ -197,4 +184,23 @@ static int __init realtek_rtl_of_init(struct device_node *node, struct device_no
 	return 0;
 }
 
+static int __init realtek_rtl_of_init(struct device_node *node, struct device_node *parent)
+{
+	unsigned int cpu;
+
+	for_each_present_cpu(cpu) {
+		realtek_ictl_base[cpu] = of_iomap(node, cpu);
+		if (!realtek_ictl_base[cpu])
+			return -ENXIO;
+
+		/* Disable all cascaded interrupts and clear routing */
+		for (unsigned int hw_irq = 0; hw_irq < RTL_ICTL_NUM_INPUTS; hw_irq++) {
+			disable_gimr(cpu, hw_irq);
+			write_irr(cpu, hw_irq, 0);
+		}
+	}
+
+	return realtek_setup_parents(node);
+}
+
 IRQCHIP_DECLARE(realtek_rtl_intc, "realtek,rtl-intc", realtek_rtl_of_init);
-- 
2.54.0