[PATCH v7 1/3] PM: sleep: wakeirq: Add support for dedicated shared wake IRQ setup

[Krishna Chaitanya Chundru]

Some devices require more flexibility when configuring their dedicated
wake-up interrupts, such as support for IRQF_SHARED or other IRQ flags.
This is particularly useful in PCIe systems where multiple endpoints
(e.g., Wi-Fi and Bluetooth controllers) share a common WAKE# signal
line which requests platform to re-establish power and reference clocks
to the components. In such cases, drivers can use this new API
dev_pm_set_dedicated_shared_wake_irq() to register a shared wake IRQ.

Update the internal helper __dev_pm_set_dedicated_wake_irq() to accept an
irq_flags argument. Modify the existing dev_pm_set_dedicated_wake_irq()
and dev_pm_set_dedicated_wake_irq_reverse() to preserve current behavior.

When IRQ registered with IRQF_SHARED we can't use IRQF_NO_AUTOEN flag,
so after registering for irq, disable it explicitly.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@xxxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki (Intel) <rafael@xxxxxxxxxx>
---
 drivers/base/power/wakeirq.c | 39 ++++++++++++++++++++++++++++++++++-----
 include/linux/pm_wakeirq.h   |  6 ++++++
 2 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c
index c0809d18fc5406b224206e0c8e5028aa8f4183b0..a3ac133496d1aadd31a2a9517322f4ff1c5be7b4 100644
--- a/drivers/base/power/wakeirq.c
+++ b/drivers/base/power/wakeirq.c
@@ -171,7 +171,8 @@ static irqreturn_t handle_threaded_wake_irq(int irq, void *_wirq)
 	return IRQ_HANDLED;
 }
 
-static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag)
+static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned int flag,
+					   unsigned int irq_flags)
 {
 	struct wake_irq *wirq;
 	int err;
@@ -200,8 +201,7 @@ static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned
 	 * so we use a threaded irq.
 	 */
 	err = request_threaded_irq(irq, NULL, handle_threaded_wake_irq,
-				   IRQF_ONESHOT | IRQF_NO_AUTOEN,
-				   wirq->name, wirq);
+				   IRQF_ONESHOT | irq_flags, wirq->name, wirq);
 	if (err)
 		goto err_free_name;
 
@@ -237,7 +237,7 @@ static int __dev_pm_set_dedicated_wake_irq(struct device *dev, int irq, unsigned
  */
 int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
 {
-	return __dev_pm_set_dedicated_wake_irq(dev, irq, 0);
+	return __dev_pm_set_dedicated_wake_irq(dev, irq, 0, IRQF_NO_AUTOEN);
 }
 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
 
@@ -258,10 +258,39 @@ EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq);
  */
 int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
 {
-	return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE);
+	return __dev_pm_set_dedicated_wake_irq(dev, irq, WAKE_IRQ_DEDICATED_REVERSE,
+					       IRQF_NO_AUTOEN);
 }
 EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_wake_irq_reverse);
 
+/**
+ * dev_pm_set_dedicated_shared_wake_irq - Request a dedicated shared wake-up interrupt
+ * @dev: Device entry
+ * @irq: Device wake-up interrupt
+ * @flags: Custom IRQ flags (e.g., IRQ_TYPE_EDGE_FALLING)
+ *
+ * This API sets up a threaded interrupt handler for a device that has
+ * a shared wake-up interrupt in addition to the device IO interrupt. It also
+ * sets IRQ flags like IRQ_TYPE_EDGE_FALLING passed by the caller.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int dev_pm_set_dedicated_shared_wake_irq(struct device *dev, int irq, unsigned long flags)
+{
+	struct wake_irq *wirq;
+	int ret;
+
+	ret =  __dev_pm_set_dedicated_wake_irq(dev, irq, 0, IRQF_SHARED | flags);
+	if (ret)
+		return ret;
+
+	wirq = dev->power.wakeirq;
+	disable_irq_nosync(wirq->irq);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_set_dedicated_shared_wake_irq);
+
 /**
  * dev_pm_enable_wake_irq_check - Checks and enables wake-up interrupt
  * @dev: Device
diff --git a/include/linux/pm_wakeirq.h b/include/linux/pm_wakeirq.h
index 25b63ed51b765c2c6919f259668a12675330835e..61f1e840745b56baa57db37563e450cb2d757a85 100644
--- a/include/linux/pm_wakeirq.h
+++ b/include/linux/pm_wakeirq.h
@@ -11,6 +11,7 @@ extern int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq);
 extern int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq);
 extern void dev_pm_clear_wake_irq(struct device *dev);
 extern int devm_pm_set_wake_irq(struct device *dev, int irq);
+extern int dev_pm_set_dedicated_shared_wake_irq(struct device *dev, int irq, unsigned long flags);
 
 #else	/* !CONFIG_PM */
 
@@ -38,5 +39,10 @@ static inline int devm_pm_set_wake_irq(struct device *dev, int irq)
 	return 0;
 }
 
+static inline int dev_pm_set_dedicated_shared_wake_irq(struct device *dev,
+						       int irq, unsigned long flags)
+{
+	return 0;
+}
 #endif	/* CONFIG_PM */
 #endif	/* _LINUX_PM_WAKEIRQ_H */

-- 
2.34.1