[ARM] 4793/1: S3C24XX: Add IRQ->GPIO pin mapping function

Add the reverse of s3c2410_gpio_getirq to convert
a IRQ  number into a GPIO pin number.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 27 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c24xx/gpio.c b/arch/arm/plat-s3c24xx/gpio.c
index 7cc6faec25d9..ee99dcc7f0bd 100644
--- a/arch/arm/plat-s3c24xx/gpio.c
+++ b/arch/arm/plat-s3c24xx/gpio.c
@@ -199,3 +199,19 @@ int s3c2410_gpio_getirq(unsigned int pin)
 }
 
 EXPORT_SYMBOL(s3c2410_gpio_getirq);
+
+int s3c2410_gpio_irq2pin(unsigned int irq)
+{
+        if (irq >= IRQ_EINT0 && irq <= IRQ_EINT3)
+                return S3C2410_GPF0 + (irq - IRQ_EINT0);
+
+        if (irq >= IRQ_EINT4 && irq <= IRQ_EINT7)
+                return S3C2410_GPF4 + (irq - IRQ_EINT4);
+
+        if (irq >= IRQ_EINT8 && irq <= IRQ_EINT23)
+                return S3C2410_GPG0 + (irq - IRQ_EINT8);
+
+        return -EINVAL;
+}
+
+EXPORT_SYMBOL(s3c2410_gpio_irq2pin);
diff --git a/include/asm-arm/arch-s3c2410/hardware.h b/include/asm-arm/arch-s3c2410/hardware.h
index 20509e4540f6..29592c3ebf22 100644
--- a/include/asm-arm/arch-s3c2410/hardware.h
+++ b/include/asm-arm/arch-s3c2410/hardware.h
@@ -50,6 +50,17 @@ extern unsigned int s3c2410_gpio_getcfg(unsigned int pin);
 
 extern int s3c2410_gpio_getirq(unsigned int pin);
 
+/* s3c2410_gpio_irq2pin
+ *
+ * turn the given irq number into the corresponding GPIO number
+ *
+ * returns:
+ *      < 0 = no pin
+ *      >=0 = gpio pin number
+*/
+
+extern int s3c2410_gpio_irq2pin(unsigned int irq);
+
 #ifdef CONFIG_CPU_S3C2400
 
 extern int s3c2400_gpio_getirq(unsigned int pin);