gpio: move the subdriver data pointer into gpio_device

We move to manage this pointer under gpiolib control rather than
leave it in the subdevice's gpio_chip. We can not NULL it after
gpiochip_remove so at to keep things tight.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpiolib.c

@@ -480,8 +480,7 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
 		goto err_free_gdev;
 	}
 	gdev->ngpio = chip->ngpio;
-	/* FIXME: move driver data into gpio_device dev_set_drvdata() */
-	chip->data = data;
+	gdev->data = data;
 
 	spin_lock_irqsave(&gpio_lock, flags);
 
@@ -602,6 +601,15 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
 }
 EXPORT_SYMBOL_GPL(gpiochip_add_data);
 
+/**
+ * gpiochip_get_data() - get per-subdriver data for the chip
+ */
+void *gpiochip_get_data(struct gpio_chip *chip)
+{
+	return chip->gpiodev->data;
+}
+EXPORT_SYMBOL_GPL(gpiochip_get_data);
+
 /**
  * gpiochip_remove() - unregister a gpio_chip
  * @chip: the chip to unregister
@@ -626,6 +634,11 @@ void gpiochip_remove(struct gpio_chip *chip)
 	gpiochip_remove_pin_ranges(chip);
 	gpiochip_free_hogs(chip);
 	of_gpiochip_remove(chip);
+	/*
+	 * We accept no more calls into the driver from this point, so
+	 * NULL the driver data pointer
+	 */
+	gdev->data = NULL;
 
 	spin_lock_irqsave(&gpio_lock, flags);
 	for (i = 0; i < gdev->ngpio; i++) {

drivers/gpio/gpiolib.h

@@ -37,6 +37,7 @@ struct acpi_device;
  * of the @descs array.
  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
  * at device creation time.
+ * @data: per-instance data assigned by the driver
  * @list: links gpio_device:s together for traversal
  *
  * This state container holds most of the runtime variable data
@@ -54,6 +55,7 @@ struct gpio_device {
 	struct gpio_desc	*descs;
 	int			base;
 	u16			ngpio;
+	void			*data;
 	struct list_head        list;
 
 #ifdef CONFIG_PINCTRL

include/linux/gpio/driver.h

@@ -25,7 +25,6 @@ struct gpio_device;
  * @gpiodev: the internal state holder, opaque struct
  * @parent: optional parent device providing the GPIOs
  * @owner: helps prevent removal of modules exporting active GPIOs
- * @data: per-instance data assigned by the driver
  * @request: optional hook for chip-specific activation, such as
  *	enabling module power and clock; may sleep
  * @free: optional hook for chip-specific deactivation, such as
@@ -109,7 +108,6 @@ struct gpio_chip {
 	struct gpio_device	*gpiodev;
 	struct device		*parent;
 	struct module		*owner;
-	void			*data;
 
 	int			(*request)(struct gpio_chip *chip,
 						unsigned offset);
@@ -202,10 +200,7 @@ void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
 
 /* get driver data */
-static inline void *gpiochip_get_data(struct gpio_chip *chip)
-{
-	return chip->data;
-}
+void *gpiochip_get_data(struct gpio_chip *chip);
 
 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);