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-rw-r--r--drivers/gpio/gpiolib.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 713ca0e37f23..73fd328f6fe4 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1153,6 +1153,38 @@ 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.