[ARM] 4275/1: generic gpio layer for ixp4xx

This patch brings generic gpio layer support to ixp4xx. It creates
functions needed for gpio->irq and irq->gpio translation.

It expects and initial value to be passed to
gpio_direction_output() which has been introduced by
commit 28735a7253a6c24364765e80a5428b4a151fccc2 in Linus git tree.

Generic gpio layer is going to be used by pxa2xx_udc driver.

Signed-off-by: Milan Svoboda <msvoboda@ra.rockwell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index 45068c3..39f2eeb 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -102,6 +102,29 @@ static signed char irq2gpio[32] = {
 	 7,  8,  9, 10, 11, 12, -1, -1,
 };
 
+int gpio_to_irq(int gpio)
+{
+	int irq;
+
+	for (irq = 0; irq < 32; irq++) {
+		if (irq2gpio[irq] == gpio)
+			return irq;
+	}
+	return -EINVAL;
+}
+EXPORT_SYMBOL(gpio_to_irq);
+
+int irq_to_gpio(int irq)
+{
+	int gpio = (irq < 32) ? irq2gpio[irq] : -EINVAL;
+
+	if (gpio == -1)
+		return -EINVAL;
+
+	return gpio;
+}
+EXPORT_SYMBOL(irq_to_gpio);
+
 static int ixp4xx_set_irq_type(unsigned int irq, unsigned int type)
 {
 	int line = irq2gpio[irq];