2 files changed, 44 insertions, 3 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.
diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index fde53a3a45a3..c8618d3282cf 100644
--- a/drivers/of/gpio.c
+++ b/drivers/of/gpio.c
@@ -46,7 +46,7 @@ int of_get_gpio_flags(struct device_node *np, int index,
                 goto err0;
         }
 
-        gc = gpio_np->data;
+        gc = of_node_to_gpiochip(gpio_np);
         if (!gc) {
                 pr_debug("%s: gpio controller %s isn't registered\n",
                          np->full_name, gpio_np->full_name);
@@ -193,7 +193,6 @@ int of_mm_gpiochip_add(struct device_node *np,
         if (mm_gc->save_regs)
                 mm_gc->save_regs(mm_gc);
 
-        np->data = &mm_gc->gc;
         mm_gc->gc.of_node = np;
 
         ret = gpiochip_add(gc);
@@ -207,7 +206,6 @@ int of_mm_gpiochip_add(struct device_node *np,
                  np->full_name, gc->base);
         return 0;
 err2:
-        np->data = NULL;
         iounmap(mm_gc->regs);
 err1:
         kfree(gc->label);
@@ -217,3 +215,14 @@ err0:
         return ret;
 }
 EXPORT_SYMBOL(of_mm_gpiochip_add);
+
+/* Private function for resolving node pointer to gpio_chip */
+static int of_gpiochip_is_match(struct gpio_chip *chip, void *data)
+{
+        return chip->of_node == data;
+}
+
+struct gpio_chip *of_node_to_gpiochip(struct device_node *np)
+{
+        return gpiochip_find(np, of_gpiochip_is_match);
+}