[PATCH v4 01/10] gpio: Add support for hierarchical IRQ domains

Lina Iyer
2019-03-13T21:18:35Z

From: Thierry Reding <treding@nvidia.com>

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@nvidia.com>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
---
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 d1adfdf50fb3..46ccb9b174b9 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1895,7 +1895,9 @@ 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;
@@ -1905,9 +1907,14 @@ 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 07cddbf45186..88ef196f96ec 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -48,6 +48,12 @@ struct gpio_irq_chip {
*/
const struct irq_domain_ops *domain_ops;

+ /**
+ * @parent_domain:
+ *
+ */
+ struct irq_domain *parent_domain;
+
/**
* @handler:
*
--
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