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>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 42fb2fd24c0c..83c3fe3a136b 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -438,6 +438,7 @@ int gpio_export(unsigned gpio, bool direction_may_change)
         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 @@ int gpio_export(unsigned gpio, bool direction_may_change)
         }
         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 @@ void gpio_unexport(unsigned gpio)
         mutex_lock(&sysfs_lock);
 
         desc = &gpio_desc[gpio];
+
         if (test_bit(FLAG_EXPORT, &desc->flags)) {
                 struct device   *dev = NULL;