gpio/pinctrl: sunxi: stop poking around in private vars

BugLink: http://bugs.launchpad.net/bugs/1632527

This kind of hacks disturbs the refactoring of the gpiolib.

The descriptor table belongs to the gpiolib, if we want to know
something about something in it, use or define the proper accessor
functions. Let's add this gpiochip_lins_is_irq() to do what the
sunxi driver is trying at so we can privatize the descriptors
properly.

Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
(backported from commit 6cee3821)
Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/gpio/gpiolib.c

@@ -1701,6 +1701,15 @@ void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
 }
 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
 
+bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset)
+{
+	if (offset >= chip->ngpio)
+		return false;
+
+	return test_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
+}
+EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
+
 /**
  * gpiod_get_raw_value_cansleep() - return a gpio's raw value
  * @desc: gpio whose value will be returned

drivers/pinctrl/sunxi/pinctrl-sunxi.c

@@ -457,8 +457,8 @@ static int sunxi_pinctrl_gpio_get(struct gpio_chip *chip, unsigned offset)
 	struct sunxi_pinctrl *pctl = dev_get_drvdata(chip->dev);
 	u32 reg = sunxi_data_reg(offset);
 	u8 index = sunxi_data_offset(offset);
-	u32 set_mux = pctl->desc->irq_read_needs_mux &&
-			test_bit(FLAG_USED_AS_IRQ, &chip->desc[offset].flags);
+	bool set_mux = pctl->desc->irq_read_needs_mux &&
+		gpiochip_line_is_irq(chip, offset);
 	u32 val;
 
 	if (set_mux)

include/linux/gpio/driver.h

@@ -180,6 +180,7 @@ extern struct gpio_chip *gpiochip_find(void *data,
 /* lock/unlock as IRQ */
 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset);
 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset);
+bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
 
 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);