brcm63xx: implement gpio_to_irq for bcm63xx-gpio

Add support for mapping some GPIO lines to IRQs. GPIO to IRQ mappings
were found out through experimentation, helped by having the GPIO as
output still toggling the IRQ input.

Based-on: http://patchwork.ozlabs.org/patch/660534/
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

target/linux/brcm63xx/dts/bcm6318.dtsi

@@ -65,6 +65,10 @@
 			#gpio-cells = <2>;
 
 			ngpios = <18>;
+
+			interrupt-parent = <&ext_intc>;
+			interrupts = <0 0>, <1 0>;
+			interrupt-names = "gpio1", "gpio2";
 		};
 
 		gpio0: gpio-controller@10000084 {

target/linux/brcm63xx/dts/bcm63268.dtsi

@@ -72,6 +72,10 @@
 			#gpio-cells = <2>;
 
 			ngpios = <20>;
+
+			interrupt-parent = <&periph_intc>;
+			interrupts = <0 0>, <1 0>, <2 0>, <3 0>;
+			interrupt-names = "gpio0", "gpio1", "gpio2", "gpio3";
 		};
 
 		gpio0: gpio-controller@100000c4 {

target/linux/brcm63xx/dts/bcm6328.dtsi

@@ -62,6 +62,11 @@
 
 			gpio-controller;
 			#gpio-cells = <2>;
+
+			interrupt-parent = <&ext_intc>;
+			interrupts = <3 0>, <2 0>, <0 0>, <1 0>;
+			interrupt-names = "gpio12", "gpio15",
+					  "gpio23", "gpio24";
 		};
 	};
 };

target/linux/brcm63xx/dts/bcm6348.dtsi

@@ -78,6 +78,10 @@
 			#gpio-cells = <2>;
 
 			ngpios = <5>;
+
+			interrupt-parent = <&ext_intc>;
+			interrupts = <0 0>, <1 0>, <2 0>, <3 0>;
+			interrupt-names = "gpio0", "gpio1", "gpio2", "gpio3";
 		};
 
 		gpio0: gpio-controller@fffe0404 {

target/linux/brcm63xx/dts/bcm6358.dtsi

@@ -94,6 +94,15 @@
 			#gpio-cells = <2>;
 
 			ngpios = <8>;
+
+			interrupts-extended = <&ext_intc1 0 0>,
+					      <&ext_intc1 1 0>,
+					      <&ext_intc0 0 0>,
+					      <&ext_intc0 1 0>,
+					      <&ext_intc0 2 0>,
+					      <&ext_intc0 3 0>;
+			interrupt-names = "gpio0", "gpio1", "gpio2", "gpio3",
+					  "gpio4", "gpio5";
 		};
 
 		gpio0: gpio-controller@fffe0084 {

target/linux/brcm63xx/dts/bcm6362.dtsi

@@ -80,6 +80,11 @@
 
 			gpio-controller;
 			#gpio-cells = <2>;
+
+			interrupt-parent = <&ext_intc>;
+			interrupts = <0 0>, <1 0>, <2 0>, <3 0>;
+			interrupt-names = "gpio24", "gpio25",
+					  "gpio26", "gpio27";
 		};
 	};
 };

target/linux/brcm63xx/dts/bcm6368.dtsi

@@ -84,6 +84,15 @@
 			#gpio-cells = <2>;
 
 			ngpios = <6>;
+
+			interrupts-extended = <&ext_intc1 0 0>,
+					      <&ext_intc1 1 0>,
+					      <&ext_intc0 0 0>,
+					      <&ext_intc0 1 0>,
+					      <&ext_intc0 2 0>,
+					      <&ext_intc0 3 0>;
+			interrupt-names = "gpio0", "gpio1", "gpio2", "gpio3",
+					  "gpio4", "gpio5";
 		};
 
 		gpio0: gpio-controller@10000084 {

target/linux/brcm63xx/patches-4.4/374-gpio-add-a-simple-GPIO-driver-for-bcm63xx.patch

@@ -40,7 +40,7 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  obj-$(CONFIG_GPIO_CLPS711X)	+= gpio-clps711x.o
 --- /dev/null
 +++ b/drivers/gpio/gpio-bcm63xx.c
-@@ -0,0 +1,122 @@
+@@ -0,0 +1,134 @@
 +/*
 + * Driver for BCM63XX memory-mapped GPIO controllers, based on
 + * Generic driver for memory-mapped GPIO controllers.
@@ -73,8 +73,17 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +#include <linux/mod_devicetable.h>
 +#include <linux/basic_mmio_gpio.h>
 +#include <linux/of.h>
++#include <linux/of_irq.h>
 +#include <linux/of_gpio.h>
 +
++static int bcm63xx_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
++{
++	char irq_name[7]; /* "gpioXX" */
++
++	sprintf(irq_name, "gpio%d", gpio);
++	return of_irq_get_byname(chip->of_node, irq_name);
++}
++
 +static int bcm63xx_gpio_probe(struct platform_device *pdev)
 +{
 +	struct device *dev = &pdev->dev;
@@ -126,6 +135,9 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +		if (!of_property_read_u32(dev->of_node, "ngpios", &ngpios))
 +			bgc->gc.ngpio = ngpios;
 +
++		if (of_get_property(dev->of_node, "interrupt-names", NULL))
++			bgc->gc.to_irq = bcm63xx_gpio_to_irq;
++
 +	} else if (pdata) {
 +		bgc->gc.base = pdata->base;
 +		if (pdata->ngpio > 0)