pinctrl: sunxi: create irq/pin mapping during init

The irq/pin mapping is used to lookup the pin to mux to the irq
function when the irq is enabled. It is created when gpio_to_irq
is called. Creating the mapping during init allows us to map the
interrupts directly from the device tree.

Originally the IRQ to pin mapping was created when gpio_to_irq
was called with a GPIO handle. The mapping in turn is used to mux
the pin into EINT mode.

If the mapping is created during gpio_to_irq, we can't use the
interrupts directly, i.e. through the DT with "interrupts = <&pio A 4>".

Instead we'd have to use "gpios = <&pio A B>", then pass the gpio
through to gpio_to_irq.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sunxi/pinctrl-sunxi.c

@@ -525,8 +525,6 @@ static int sunxi_pinctrl_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 	if (!desc)
 		return -EINVAL;
 
-	pctl->irq_array[desc->irqnum] = offset;
-
 	dev_dbg(chip->dev, "%s: request IRQ for GPIO %d, return %d\n",
 		chip->label, offset + chip->base, desc->irqnum);
 
@@ -727,6 +725,9 @@ static int sunxi_pinctrl_build_state(struct platform_device *pdev)
 		struct sunxi_desc_function *func = pin->functions;
 
 		while (func->name) {
+			/* Create interrupt mapping while we're at it */
+			if (!strcmp(func->name, "irq"))
+				pctl->irq_array[func->irqnum] = pin->pin.number;
 			sunxi_pinctrl_add_function(pctl, func->name);
 			func++;
 		}