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authorLinus Walleij <linus.walleij@linaro.org>2013-10-04 15:15:35 +0200
committerLinus Walleij <linus.walleij@linaro.org>2014-01-03 22:26:13 +0100
commitbdd272cbb97a66cf83061d22cfd19beb7267943a (patch)
treeb43334bc0f1b3f76404c4841088a25bc44cd1d28
parentfe989145447341bff1ed68bd8aaee12ea860d461 (diff)
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>
-rw-r--r--Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt5
-rw-r--r--drivers/irqchip/irq-versatile-fpga.c15
2 files changed, 18 insertions, 2 deletions
diff --git a/Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt b/Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt
index 9989eda755d9..c9cf605bb995 100644
--- a/Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt
+++ b/Documentation/devicetree/bindings/arm/versatile-fpga-irq.txt
@@ -29,3 +29,8 @@ pic: pic@14000000 {
clear-mask = <0xffffffff>;
valid-mask = <0x003fffff>;
};
+
+Optional properties:
+- interrupts: if the FPGA IRQ controller is cascaded, i.e. if its IRQ
+ output is simply connected to the input of another IRQ controller,
+ then the parent IRQ shall be specified in this property.
diff --git a/drivers/irqchip/irq-versatile-fpga.c b/drivers/irqchip/irq-versatile-fpga.c
index 47a52ab580d8..3ae2bb8d9cf2 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 @@ void __init fpga_irq_init(void __iomem *base, const char *name, int irq_start,
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 @@ int __init fpga_irq_of_init(struct device_node *node,
void __iomem *base;
u32 clear_mask;
u32 valid_mask;
+ int parent_irq;
if (WARN_ON(!node))
return -ENODEV;
@@ -193,7 +199,12 @@ int __init fpga_irq_of_init(struct device_node *node,
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);