1 files changed, 46 insertions, 3 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index cae1b8c5b08c..3ca36542e338 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -722,7 +722,7 @@ int gpio_export(unsigned gpio, bool direction_may_change)
         unsigned long           flags;
         struct gpio_desc        *desc;
         int                     status = -EINVAL;
-        char                    *ioname = NULL;
+        const char              *ioname = NULL;
 
         /* can't export until sysfs is available ... */
         if (!gpio_class.p) {
@@ -753,7 +753,7 @@ int gpio_export(unsigned gpio, bool direction_may_change)
                 struct device   *dev;
 
                 dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
-                                desc, ioname ? ioname : "gpio%d", gpio);
+                                desc, ioname ? ioname : "gpio%u", gpio);
                 if (!IS_ERR(dev)) {
                         status = sysfs_create_group(&dev->kobj,
                                                 &gpio_attr_group);
@@ -1106,7 +1106,7 @@ unlock:
 fail:
         /* failures here can mean systems won't boot... */
         if (status)
-                pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n",
+                pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n",
                         chip->base, chip->base + chip->ngpio - 1,
                         chip->label ? : "generic");
         return status;
@@ -1447,6 +1447,49 @@ fail:
 }
 EXPORT_SYMBOL_GPL(gpio_direction_output);
 
+/**
+ * gpio_set_debounce - sets @debounce time for a @gpio
+ * @gpio: the gpio to set debounce time
+ * @debounce: debounce time is microseconds
+ */
+int gpio_set_debounce(unsigned gpio, unsigned debounce)
+{
+        unsigned long           flags;
+        struct gpio_chip        *chip;
+        struct gpio_desc        *desc = &gpio_desc[gpio];
+        int                     status = -EINVAL;
+
+        spin_lock_irqsave(&gpio_lock, flags);
+
+        if (!gpio_is_valid(gpio))
+                goto fail;
+        chip = desc->chip;
+        if (!chip || !chip->set || !chip->set_debounce)
+                goto fail;
+        gpio -= chip->base;
+        if (gpio >= chip->ngpio)
+                goto fail;
+        status = gpio_ensure_requested(desc, gpio);
+        if (status < 0)
+                goto fail;
+
+        /* now we know the gpio is valid and chip won't vanish */
+
+        spin_unlock_irqrestore(&gpio_lock, flags);
+
+        might_sleep_if(extra_checks && chip->can_sleep);
+
+        return chip->set_debounce(chip, gpio, debounce);
+
+fail:
+        spin_unlock_irqrestore(&gpio_lock, flags);
+        if (status)
+                pr_debug("%s: gpio-%d status %d\n",
+                        __func__, gpio, status);
+
+        return status;
+}
+EXPORT_SYMBOL_GPL(gpio_set_debounce);
 
 /* I/O calls are only valid after configuration completed; the relevant
  * "is this a valid GPIO" error checks should already have been done.