pinctrl: sunxi: Fix multi bank interrupt support in gpio_to_irq

When mapping the interrupts, the gpio_to_irq function did not consider
the bank number of the gpio pin in question, only the offset or the
interrupt number in the bank. As a result, requests for interrupts in
the later banks get mapped to the first bank.

This issue was discovered while enabling mmc on the new sun8i platform.
The tablet I have uses a pin/interrupt from the second bank to do mmc
card detection. Tested on this very device with register inspection and
actual mmc card insertion/removal.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sunxi/pinctrl-sunxi.c

@@ -520,6 +520,7 @@ static int sunxi_pinctrl_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	struct sunxi_pinctrl *pctl = dev_get_drvdata(chip->dev);
 	struct sunxi_desc_function *desc;
+	unsigned irqnum;
 
 	if (offset >= chip->ngpio)
 		return -ENXIO;
@@ -528,10 +529,12 @@ static int sunxi_pinctrl_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 	if (!desc)
 		return -EINVAL;
 
+	irqnum = desc->irqbank * IRQ_PER_BANK + desc->irqnum;
+
 	dev_dbg(chip->dev, "%s: request IRQ for GPIO %d, return %d\n",
-		chip->label, offset + chip->base, desc->irqnum);
+		chip->label, offset + chip->base, irqnum);
 
-	return irq_find_mapping(pctl->domain, desc->irqnum);
+	return irq_find_mapping(pctl->domain, irqnum);
 }
 
 static int sunxi_pinctrl_irq_request_resources(struct irq_data *d)