1 files changed, 53 insertions, 9 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 3ca36542e33..6a6bd569e1f 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -8,6 +8,7 @@
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/gpio.h>
+#include <linux/of_gpio.h>
 #include <linux/idr.h>
 #include <linux/slab.h>
 
@@ -893,10 +894,12 @@ EXPORT_SYMBOL_GPL(gpio_sysfs_set_active_low);
 void gpio_unexport(unsigned gpio)
 {
 	struct gpio_desc	*desc;
-	int			status = -EINVAL;
+	int			status = 0;
 
-	if (!gpio_is_valid(gpio))
+	if (!gpio_is_valid(gpio)) {
+		status = -EINVAL;
 		goto done;
+	}
 
 	mutex_lock(&sysfs_lock);
 
@@ -911,7 +914,6 @@ void gpio_unexport(unsigned gpio)
 			clear_bit(FLAG_EXPORT, &desc->flags);
 			put_device(dev);
 			device_unregister(dev);
-			status = 0;
 		} else
 			status = -ENODEV;
 	}
@@ -1099,16 +1101,24 @@ int gpiochip_add(struct gpio_chip *chip)
 		}
 	}
 
+	of_gpiochip_add(chip);
+
 unlock:
 	spin_unlock_irqrestore(&gpio_lock, flags);
-	if (status == 0)
-		status = gpiochip_export(chip);
+
+	if (status)
+		goto fail;
+
+	status = gpiochip_export(chip);
+	if (status)
+		goto fail;
+
+	return 0;
 fail:
 	/* failures here can mean systems won't boot... */
-	if (status)
-		pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n",
-			chip->base, chip->base + chip->ngpio - 1,
-			chip->label ? : "generic");
+	pr_err("gpiochip_add: gpios %d..%d (%s) failed to register\n",
+		chip->base, chip->base + chip->ngpio - 1,
+		chip->label ? : "generic");
 	return status;
 }
 EXPORT_SYMBOL_GPL(gpiochip_add);
@@ -1127,6 +1137,8 @@ int gpiochip_remove(struct gpio_chip *chip)
 
 	spin_lock_irqsave(&gpio_lock, flags);
 
+	of_gpiochip_remove(chip);
+
 	for (id = chip->base; id < chip->base + chip->ngpio; id++) {
 		if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {
 			status = -EBUSY;
@@ -1147,6 +1159,38 @@ int gpiochip_remove(struct gpio_chip *chip)
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
 
+/**
+ * gpiochip_find() - iterator for locating a specific gpio_chip
+ * @data: data to pass to match function
+ * @callback: Callback function to check gpio_chip
+ *
+ * Similar to bus_find_device.  It returns a reference to a gpio_chip as
+ * determined by a user supplied @match callback.  The callback should return
+ * 0 if the device doesn't match and non-zero if it does.  If the callback is
+ * non-zero, this function will return to the caller and not iterate over any
+ * more gpio_chips.
+ */
+struct gpio_chip *gpiochip_find(void *data,
+				int (*match)(struct gpio_chip *chip, void *data))
+{
+	struct gpio_chip *chip = NULL;
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&gpio_lock, flags);
+	for (i = 0; i < ARCH_NR_GPIOS; i++) {
+		if (!gpio_desc[i].chip)
+			continue;
+
+		if (match(gpio_desc[i].chip, data)) {
+			chip = gpio_desc[i].chip;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&gpio_lock, flags);
+
+	return chip;
+}
 
 /* These "optional" allocation calls help prevent drivers from stomping
  * on each other, and help provide better diagnostics in debugfs.