From: Thierry Reding <treding@xxxxxxxxxx>
Hierarchical IRQ domains can be used to stack different IRQ controllers
on top of each other. One specific use-case where this can be useful is
if a power management controller has top-level controls for wakeup
interrupts. In such cases, the power management controller can be a
parent to other interrupt controllers and program additional registers
when an IRQ has its wake capability enabled or disabled.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 15 +++++++++++----
include/linux/gpio/driver.h | 6 ++++++
2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index a53d17745d21..94146093ee95 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1918,7 +1918,9 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
type = IRQ_TYPE_NONE;
}
- gpiochip->to_irq = gpiochip_to_irq;
+ if (!gpiochip->to_irq)
+ gpiochip->to_irq = gpiochip_to_irq;
+
gpiochip->irq.default_type = type;
gpiochip->irq.lock_key = lock_key;
gpiochip->irq.request_key = request_key;
@@ -1928,9 +1930,14 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
else
ops = &gpiochip_domain_ops;
- gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
- gpiochip->irq.first,
- ops, gpiochip);
+ if (gpiochip->irq.parent_domain)
+ gpiochip->irq.domain = irq_domain_add_hierarchy(gpiochip->irq.parent_domain,
+ 0, gpiochip->ngpio,
+ np, ops, gpiochip);
+ else
+ gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,
+ gpiochip->irq.first,
+ ops, gpiochip);
if (!gpiochip->irq.domain)
return -EINVAL;
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index d8dcd0e44cab..fcd09a396d76 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -47,6 +47,12 @@ struct gpio_irq_chip {
*/
const struct irq_domain_ops *domain_ops;
+ /**
+ * @parent_domain:
+ *
+ */
+ struct irq_domain *parent_domain;
+
/**
* @handler:
*
--
2.19.0
