From: Thierry Reding <[email protected]> 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 <[email protected]> --- Changes in v2: - select IRQ_DOMAIN_HIERARCHY to avoid build failure - move more code into the gpiolib core drivers/gpio/Kconfig | 2 +- drivers/gpio/gpiolib.c | 33 +++++++++++++++++++++++++++++---- include/linux/gpio/driver.h | 6 ++++++ 3 files changed, 36 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 587e5f005b61..1d8abaab09f7 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -43,7 +43,7 @@ config GPIO_ACPI depends on ACPI config GPIOLIB_IRQCHIP - select IRQ_DOMAIN + select IRQ_DOMAIN_HIERARCHY bool config DEBUG_GPIO diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index cd84315ad586..247ca4c1241f 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1777,9 +1777,22 @@ static const struct irq_domain_ops gpiochip_domain_ops = { static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) { + struct irq_domain *domain = chip->irq.domain; + if (!gpiochip_irqchip_irq_valid(chip, offset)) return -ENXIO; + if (irq_domain_is_hierarchy(domain)) { + struct irq_fwspec spec; + + spec.fwnode = domain->fwnode; + spec.param_count = 2; + spec.param[0] = offset; + spec.param[1] = 0; + + return irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, &spec); + } + return irq_create_mapping(chip->irq.domain, offset); } @@ -1888,7 +1901,14 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip, type = IRQ_TYPE_NONE; } - gpiochip->to_irq = gpiochip_to_irq; + /* + * Allow GPIO chips to override the ->to_irq() if they really need to. + * This should only be very rarely needed, the majority should be fine + * with 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; @@ -1898,9 +1918,14 @@ 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 9c8d5d491680..eb8b35f1d8b6 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: * -- 2.19.1
