gpiolib: allow exported GPIO nodes to be named using sysfs links
Commit 926b663ce8215ba448960e1ff6e58b67a2c3b99b (gpiolib: allow GPIOs to
be named) already provides naming on the chip level. This patch provides
more flexibility by allowing multiple names where ever in sysfs on a per
GPIO basis.
Adapted from David Brownell's comments on a similar concept:
http://lkml.org/lkml/2009/4/20/203.
[randy.dunlap@oracle.com: fix build for CONFIG_GENERIC_GPIO=n]
Signed-off-by: Jani Nikula <ext-jani.1.nikula@nokia.com>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Daniel Silverstone <dsilvers@simtec.co.uk>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index e10c49a..059bd18 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -12,6 +12,8 @@
#include <linux/types.h>
#include <linux/errno.h>
+struct device;
+
/*
* Some platforms don't support the GPIO programming interface.
*
@@ -89,6 +91,15 @@
return -EINVAL;
}
+static inline int gpio_export_link(struct device *dev, const char *name,
+ unsigned gpio)
+{
+ /* GPIO can never have been exported */
+ WARN_ON(1);
+ return -EINVAL;
+}
+
+
static inline void gpio_unexport(unsigned gpio)
{
/* GPIO can never have been exported */