pinctrl: amd: Fix wakeups when IRQ is shared with SCI

On some Lenovo AMD Gen2 platforms the IRQ for the SCI and pinctrl drivers
are shared.  Due to how the s2idle loop handling works, this case needs
an extra explicit check whether the interrupt was caused by SCI or by
the GPIO controller.

To fix this rework the existing IRQ handler function to function as a
checker and an IRQ handler depending on the calling arguments.

BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1738Reported-by: Joerie de Gram <j.de.gram@gmail.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Link: https://lore.kernel.org/r/20211101014853.6177-2-mario.limonciello@amd.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-amd.c

@@ -598,14 +598,14 @@ static struct irq_chip amd_gpio_irqchip = {
 
 #define PIN_IRQ_PENDING	(BIT(INTERRUPT_STS_OFF) | BIT(WAKE_STS_OFF))
 
-static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
+static bool do_amd_gpio_irq_handler(int irq, void *dev_id)
 {
 	struct amd_gpio *gpio_dev = dev_id;
 	struct gpio_chip *gc = &gpio_dev->gc;
-	irqreturn_t ret = IRQ_NONE;
 	unsigned int i, irqnr;
 	unsigned long flags;
 	u32 __iomem *regs;
+	bool ret = false;
 	u32  regval;
 	u64 status, mask;
 
@@ -627,6 +627,14 @@ static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
 		/* Each status bit covers four pins */
 		for (i = 0; i < 4; i++) {
 			regval = readl(regs + i);
+			/* caused wake on resume context for shared IRQ */
+			if (irq < 0 && (regval & BIT(WAKE_STS_OFF))) {
+				dev_dbg(&gpio_dev->pdev->dev,
+					"Waking due to GPIO %d: 0x%x",
+					irqnr + i, regval);
+				return true;
+			}
+
 			if (!(regval & PIN_IRQ_PENDING) ||
 			    !(regval & BIT(INTERRUPT_MASK_OFF)))
 				continue;
@@ -650,9 +658,12 @@ static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
 			}
 			writel(regval, regs + i);
 			raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
-			ret = IRQ_HANDLED;
+			ret = true;
 		}
 	}
+	/* did not cause wake on resume context for shared IRQ */
+	if (irq < 0)
+		return false;
 
 	/* Signal EOI to the GPIO unit */
 	raw_spin_lock_irqsave(&gpio_dev->lock, flags);
@@ -664,6 +675,16 @@ static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
 	return ret;
 }
 
+static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)
+{
+	return IRQ_RETVAL(do_amd_gpio_irq_handler(irq, dev_id));
+}
+
+static bool __maybe_unused amd_gpio_check_wake(void *dev_id)
+{
+	return do_amd_gpio_irq_handler(-1, dev_id);
+}
+
 static int amd_get_groups_count(struct pinctrl_dev *pctldev)
 {
 	struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);
@@ -1033,6 +1054,7 @@ static int amd_gpio_probe(struct platform_device *pdev)
 		goto out2;
 
 	platform_set_drvdata(pdev, gpio_dev);
+	acpi_register_wakeup_handler(gpio_dev->irq, amd_gpio_check_wake, gpio_dev);
 
 	dev_dbg(&pdev->dev, "amd gpio driver loaded\n");
 	return ret;
@@ -1050,6 +1072,7 @@ static int amd_gpio_remove(struct platform_device *pdev)
 	gpio_dev = platform_get_drvdata(pdev);
 
 	gpiochip_remove(&gpio_dev->gc);
+	acpi_unregister_wakeup_handler(amd_gpio_check_wake, gpio_dev);
 
 	return 0;
 }