pinctrl: intel: implement gpio_irq_enable

There is unexpected gpio interrupt after irq_enable. If not
implemeted gpio_irq_enable callback, irq_enable calls irq_unmask
instead. But if there was interrupt set before the irq_enable,
unmask it may trigger the unexpected interrupt. By implementing
the gpio_irq_enable callback, do interrupt status ack, the issue
has gone.

Signed-off-by: Qi Zheng <qi.zheng@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/intel/pinctrl-intel.c

@@ -665,6 +665,35 @@ static void intel_gpio_irq_ack(struct irq_data *d)
 	spin_unlock(&pctrl->lock);
 }
 
+static void intel_gpio_irq_enable(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct intel_pinctrl *pctrl = gpiochip_get_data(gc);
+	const struct intel_community *community;
+	unsigned pin = irqd_to_hwirq(d);
+	unsigned long flags;
+
+	spin_lock_irqsave(&pctrl->lock, flags);
+
+	community = intel_get_community(pctrl, pin);
+	if (community) {
+		unsigned padno = pin_to_padno(community, pin);
+		unsigned gpp_size = community->gpp_size;
+		unsigned gpp_offset = padno % gpp_size;
+		unsigned gpp = padno / gpp_size;
+		u32 value;
+
+		/* Clear interrupt status first to avoid unexpected interrupt */
+		writel(BIT(gpp_offset), community->regs + GPI_IS + gpp * 4);
+
+		value = readl(community->regs + community->ie_offset + gpp * 4);
+		value |= BIT(gpp_offset);
+		writel(value, community->regs + community->ie_offset + gpp * 4);
+	}
+
+	spin_unlock_irqrestore(&pctrl->lock, flags);
+}
+
 static void intel_gpio_irq_mask_unmask(struct irq_data *d, bool mask)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
@@ -853,6 +882,7 @@ static irqreturn_t intel_gpio_irq(int irq, void *data)
 
 static struct irq_chip intel_gpio_irqchip = {
 	.name = "intel-gpio",
+	.irq_enable = intel_gpio_irq_enable,
 	.irq_ack = intel_gpio_irq_ack,
 	.irq_mask = intel_gpio_irq_mask,
 	.irq_unmask = intel_gpio_irq_unmask,