Revert "gpio: Allow per-parent interrupt data"

This reverts commit 304802e5b0 which is
commit cfe6807d82 upstream.

It breaks the Android api, so revert it for now.  If it needs to come
back, it can do so in an abi-safe way.

Bug: 161946584
Change-Id: I0f1f7b4de721ff23d252eef9b55678c3b6053cb7
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/gpio/gpiolib.c

@@ -1596,14 +1596,9 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc,
 	}
 
 	if (gc->irq.parent_handler) {
+		void *data = gc->irq.parent_handler_data ?: gc;
+
 		for (i = 0; i < gc->irq.num_parents; i++) {
-			void *data;
-
-			if (gc->irq.per_parent_data)
-				data = gc->irq.parent_handler_data_array[i];
-			else
-				data = gc->irq.parent_handler_data ?: gc;
-
 			/*
 			 * The parent IRQ chip is already using the chip_data
 			 * for this IRQ chip, so our callbacks simply use the

include/linux/gpio/driver.h

@@ -169,18 +169,11 @@ struct gpio_irq_chip {
 
 	/**
 	 * @parent_handler_data:
-	 * @parent_handler_data_array:
 	 *
 	 * Data associated, and passed to, the handler for the parent
-	 * interrupt. Can either be a single pointer if @per_parent_data
-	 * is false, or an array of @num_parents pointers otherwise.  If
-	 * @per_parent_data is true, @parent_handler_data_array cannot be
-	 * NULL.
+	 * interrupt.
 	 */
-	union {
-		void *parent_handler_data;
-		void **parent_handler_data_array;
-	};
+	void *parent_handler_data;
 
 	/**
 	 * @num_parents:
@@ -211,14 +204,6 @@ struct gpio_irq_chip {
 	 */
 	bool threaded;
 
-	/**
-	 * @per_parent_data:
-	 *
-	 * True if parent_handler_data_array describes a @num_parents
-	 * sized array to be used as parent data.
-	 */
-	bool per_parent_data;
-
 	/**
 	 * @init_hw: optional routine to initialize hardware before
 	 * an IRQ chip will be added. This is quite useful when