pinctrl: amd: Disable and mask interrupts on resume

This fixes a similar problem to the one observed in:
commit 4e5a04b ("pinctrl: amd: disable and mask interrupts on probe").

On some systems, during suspend/resume cycle firmware leaves
an interrupt enabled on a pin that is not used by the kernel.
This confuses the AMD pinctrl driver and causes spurious interrupts.

The driver already has logic to detect if a pin is used by the kernel.
Leverage it to re-initialize interrupt fields of a pin only if it's not
used by us.

Cc: stable@vger.kernel.org
Fixes: dbad75d ("pinctrl: add AMD GPIO driver support.")
Signed-off-by: Kornel Dulęba <korneld@chromium.org>
Link: https://lore.kernel.org/r/20230320093259.845178-1-korneld@chromium.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: Kornel Dulęba

drivers/pinctrl/pinctrl-amd.c

@@ -872,32 +872,34 @@ static const struct pinconf_ops amd_pinconf_ops = {
 	.pin_config_group_set = amd_pinconf_group_set,
 };
 
-static void amd_gpio_irq_init(struct amd_gpio *gpio_dev)
+static void amd_gpio_irq_init_pin(struct amd_gpio *gpio_dev, int pin)
 {
-	struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
+	const struct pin_desc *pd;
 	unsigned long flags;
 	u32 pin_reg, mask;
-	int i;
 
 	mask = BIT(WAKE_CNTRL_OFF_S0I3) | BIT(WAKE_CNTRL_OFF_S3) |
 		BIT(INTERRUPT_MASK_OFF) | BIT(INTERRUPT_ENABLE_OFF) |
 		BIT(WAKE_CNTRL_OFF_S4);
 
-	for (i = 0; i < desc->npins; i++) {
-		int pin = desc->pins[i].number;
-		const struct pin_desc *pd = pin_desc_get(gpio_dev->pctrl, pin);
-
-		if (!pd)
-			continue;
+	pd = pin_desc_get(gpio_dev->pctrl, pin);
+	if (!pd)
+		return;
 
-		raw_spin_lock_irqsave(&gpio_dev->lock, flags);
+	raw_spin_lock_irqsave(&gpio_dev->lock, flags);
+	pin_reg = readl(gpio_dev->base + pin * 4);
+	pin_reg &= ~mask;
+	writel(pin_reg, gpio_dev->base + pin * 4);
+	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
+}
 
-		pin_reg = readl(gpio_dev->base + i * 4);
-		pin_reg &= ~mask;
-		writel(pin_reg, gpio_dev->base + i * 4);
+static void amd_gpio_irq_init(struct amd_gpio *gpio_dev)
+{
+	struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
+	int i;
 
-		raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
-	}
+	for (i = 0; i < desc->npins; i++)
+		amd_gpio_irq_init_pin(gpio_dev, i);
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -950,8 +952,10 @@ static int amd_gpio_resume(struct device *dev)
 	for (i = 0; i < desc->npins; i++) {
 		int pin = desc->pins[i].number;
 
-		if (!amd_gpio_should_save(gpio_dev, pin))
+		if (!amd_gpio_should_save(gpio_dev, pin)) {
+			amd_gpio_irq_init_pin(gpio_dev, pin);
 			continue;
+		}
 
 		raw_spin_lock_irqsave(&gpio_dev->lock, flags);
 		gpio_dev->saved_regs[i] |= readl(gpio_dev->base + pin * 4) & PIN_IRQ_PENDING;