irqchip: versatile FPGA: support cascaded interrupts from DT
The Versatile FPGA interrupt controller supports cascading interrupts,
i.e. that its output is connected to the input of another interrupt
controller. This makes it possible to pass a parent interrupt from
the device tree and print it in the boot log if applicable.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/irqchip/irq-versatile-fpga.c b/drivers/irqchip/irq-versatile-fpga.c
index 47a52ab..3ae2bb8 100644
--- a/drivers/irqchip/irq-versatile-fpga.c
+++ b/drivers/irqchip/irq-versatile-fpga.c
@@ -9,6 +9,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
+#include <linux/of_irq.h>
#include <asm/exception.h>
#include <asm/mach/irq.h>
@@ -167,8 +168,12 @@
f->used_irqs++;
}
- pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs\n",
+ pr_info("FPGA IRQ chip %d \"%s\" @ %p, %u irqs",
fpga_irq_id, name, base, f->used_irqs);
+ if (parent_irq != -1)
+ pr_cont(", parent IRQ: %d\n", parent_irq);
+ else
+ pr_cont("\n");
fpga_irq_id++;
}
@@ -180,6 +185,7 @@
void __iomem *base;
u32 clear_mask;
u32 valid_mask;
+ int parent_irq;
if (WARN_ON(!node))
return -ENODEV;
@@ -193,7 +199,12 @@
if (of_property_read_u32(node, "valid-mask", &valid_mask))
valid_mask = 0;
- fpga_irq_init(base, node->name, 0, -1, valid_mask, node);
+ /* Some chips are cascaded from a parent IRQ */
+ parent_irq = irq_of_parse_and_map(node, 0);
+ if (!parent_irq)
+ parent_irq = -1;
+
+ fpga_irq_init(base, node->name, 0, parent_irq, valid_mask, node);
writel(clear_mask, base + IRQ_ENABLE_CLEAR);
writel(clear_mask, base + FIQ_ENABLE_CLEAR);