gpiolib: allow GPIOs to be named

Allow GPIOs in GPIOLIB chips to be named.  This name is then used when the
GPIO is exported to sysfs, although it could be used elsewhere if deemed
useful.

Signed-off-by: Daniel Silverstone <dsilvers@simtec.co.uk>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 42fb2fd..83c3fe3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -438,6 +438,7 @@
 	unsigned long		flags;
 	struct gpio_desc	*desc;
 	int			status = -EINVAL;
+	char			*ioname = NULL;
 
 	/* can't export until sysfs is available ... */
 	if (!gpio_class.p) {
@@ -461,11 +462,14 @@
 	}
 	spin_unlock_irqrestore(&gpio_lock, flags);
 
+	if (desc->chip->names && desc->chip->names[gpio - desc->chip->base])
+		ioname = desc->chip->names[gpio - desc->chip->base];
+
 	if (status == 0) {
 		struct device	*dev;
 
 		dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
-					desc, "gpio%d", gpio);
+				    desc, ioname ? ioname : "gpio%d", gpio);
 		if (dev) {
 			if (direction_may_change)
 				status = sysfs_create_group(&dev->kobj,
@@ -513,6 +517,7 @@
 	mutex_lock(&sysfs_lock);
 
 	desc = &gpio_desc[gpio];
+
 	if (test_bit(FLAG_EXPORT, &desc->flags)) {
 		struct device	*dev = NULL;