From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: [PATCH v3 1/2] gpio: Add support for hierarchical IRQ domains Date: Wed, 29 May 2019 16:53:21 +0200 Message-ID: <20190529145322.20630-2-thierry.reding@gmail.com> References: <20190529145322.20630-1-thierry.reding@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190529145322.20630-1-thierry.reding@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Linus Walleij Cc: Thomas Gleixner , Lina Iyer , Jon Hunter , Sowjanya Komatineni , Bitan Biswas , linux-gpio@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org From: Thierry Reding 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 --- Changes in v3: - use irq_create_fwspec_mapping() instead of irq_domain_alloc_irqs() - add missing kerneldoc for new parent_domain field - keep IRQ_DOMAIN dependency for clarity Changes in v2: - select IRQ_DOMAIN_HIERARCHY to avoid build failure - move more code into the gpiolib core drivers/gpio/Kconfig | 1 + drivers/gpio/gpiolib.c | 33 +++++++++++++++++++++++++++++---- include/linux/gpio/driver.h | 8 ++++++++ 3 files changed, 38 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 62f3fe06cd2f..b87cc36005d8 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -45,6 +45,7 @@ config GPIO_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 e013d417a936..6b64bfa90089 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1825,9 +1825,22 @@ EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate); 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] = IRQ_TYPE_NONE; + + return irq_create_fwspec_mapping(&spec); + } + return irq_create_mapping(chip->irq.domain, offset); } @@ -1936,7 +1949,14 @@ 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; @@ -1946,9 +1966,14 @@ 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 a1d273c96016..472f2c127bf6 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -48,6 +48,14 @@ struct gpio_irq_chip { */ const struct irq_domain_ops *domain_ops; + /** + * @parent_domain: + * + * If non-NULL, will be set as the parent of this GPIO interrupt + * controller's IRQ domain to establish a hierarchy. + */ + struct irq_domain *parent_domain; + /** * @handler: * -- 2.21.0