[tip: irq/core] irqchip: vic: Support cascaded VIC in device tree

[tip-bot2 for Linus Walleij]

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     a15111075a847432b90e1534095b195aac8d9ec2
Gitweb:        https://git.kernel.org/tip/a15111075a847432b90e1534095b195aac8d9ec2
Author:        Linus Walleij <linus.walleij@xxxxxxxxxx>
AuthorDate:    Wed, 19 Feb 2020 16:35:43 +01:00
Committer:     Marc Zyngier <maz@xxxxxxxxxx>
CommitterDate: Sun, 08 Mar 2020 14:25:45 

irqchip: vic: Support cascaded VIC in device tree

When transitioning some elder platforms to device tree it
becomes necessary to cascade VIC IRQ chips off another
interrupt controller.

Tested with the cascaded VIC on the Integrator/AP attached
logic module IM-PD1.

Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200219153543.137153-1-linus.walleij@xxxxxxxxxx
---
 drivers/irqchip/irq-vic.c |  9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/irqchip/irq-vic.c b/drivers/irqchip/irq-vic.c
index f3f20a3..3c87d92 100644
--- a/drivers/irqchip/irq-vic.c
+++ b/drivers/irqchip/irq-vic.c
@@ -509,9 +509,7 @@ static int __init vic_of_init(struct device_node *node,
 	void __iomem *regs;
 	u32 interrupt_mask = ~0;
 	u32 wakeup_mask = ~0;
-
-	if (WARN(parent, "non-root VICs are not supported"))
-		return -EINVAL;
+	int parent_irq;
 
 	regs = of_iomap(node, 0);
 	if (WARN_ON(!regs))
@@ -519,11 +517,14 @@ static int __init vic_of_init(struct device_node *node,
 
 	of_property_read_u32(node, "valid-mask", &interrupt_mask);
 	of_property_read_u32(node, "valid-wakeup-mask", &wakeup_mask);
+	parent_irq = of_irq_get(node, 0);
+	if (parent_irq < 0)
+		parent_irq = 0;
 
 	/*
 	 * Passing 0 as first IRQ makes the simple domain allocate descriptors
 	 */
-	__vic_init(regs, 0, 0, interrupt_mask, wakeup_mask, node);
+	__vic_init(regs, parent_irq, 0, interrupt_mask, wakeup_mask, node);
 
 	return 0;
 }