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;
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 81797ec..d6c379d 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -55,6 +55,10 @@
* handled is (base + ngpio - 1).
* @can_sleep: flag must be set iff get()/set() methods sleep, as they
* must while accessing GPIO expander chips over I2C or SPI
+ * @names: if set, must be an array of strings to use as alternative
+ * names for the GPIOs in this chip. Any entry in the array
+ * may be NULL if there is no alias for the GPIO, however the
+ * array must be @ngpio entries long.
*
* A gpio_chip can help platforms abstract various sources of GPIOs so
* they can all be accessed through a common programing interface.
@@ -92,6 +96,7 @@
struct gpio_chip *chip);
int base;
u16 ngpio;
+ char **names;
unsigned can_sleep:1;
unsigned exported:1;
};