From: Linus Walleij <linus.walleij@linaro.org>
To: "thierry.reding@gmail.com" <thierry.reding@gmail.com>,
Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
linux-tegra@vger.kernel.org,
"open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 6/9] gpio: Add support for hierarchical IRQ domains
Date: Tue, 25 Sep 2018 10:11:06 +0200 [thread overview]
Message-ID: <CACRpkdYnrf7FknvnZyFSgfT5aCrcWT4hxSnQo0UqxYfR6Fkqwg@mail.gmail.com> (raw)
In-Reply-To: <20180921102546.12745-7-thierry.reding@gmail.com>
Hi Thierry!
Thanks for the patch!
I am a bit ignorant about irqdomains so I will probably need an ACK
from some irq maintainer before I can apply this.
On Fri, Sep 21, 2018 at 12:25 PM Thierry Reding
<thierry.reding@gmail.com> wrote:
> 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>
While I think it is really important that we start supporting hierarchical
irqdomains in the gpiolib core, I want a more complete approach,
so that drivers that need hierarchical handling of irqdomains
can get the same support from gpiolib as they get for simple
domains.
> @@ -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;
So here you let the drivers override the .to_irq() function and that
I think gets confusing as we are asking gpiolib to handle our
irqchip.
> - 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);
So this part is great: if we pass in a parent domain the core helps us
create the hierarchy.
But the stuff in .to_irq() should also be handled in the gpiolib core:
the irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, &spec) for
example. That way you should not need any external .to_irq() function.
I can't see if you need to pull more stuff into the core to accomplish
that, but I think in essence the core gpiolib needs to be more helpful
with hierarchies.
Yours,
Linus Walleij
next prev parent reply other threads:[~2018-09-25 8:11 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-21 10:25 [PATCH 0/9] Implement wake event support on Tegra186 and later Thierry Reding
2018-09-21 10:25 ` [PATCH 1/9] dt-bindings: tegra186-pmc: Add interrupt controller properties Thierry Reding
2018-10-15 14:47 ` Rob Herring
2018-09-21 10:25 ` [PATCH 2/9] soc/tegra: pmc: Add Tegra194 support Thierry Reding
2018-09-21 10:25 ` [PATCH 3/9] soc/tegra: pmc: Add wake event support Thierry Reding
2018-09-21 10:35 ` Mikko Perttunen
2018-09-21 10:25 ` [PATCH 4/9] soc/tegra: pmc: Add initial Tegra186 wake events Thierry Reding
2018-09-21 10:25 ` [PATCH 5/9] soc/tegra: pmc: Add initial Tegra194 " Thierry Reding
2018-09-21 10:25 ` [PATCH 6/9] gpio: Add support for hierarchical IRQ domains Thierry Reding
2018-09-25 8:11 ` Linus Walleij [this message]
2018-09-25 9:33 ` Thierry Reding
2018-09-25 10:33 ` Linus Walleij
2018-09-25 11:17 ` Thierry Reding
2018-10-03 7:52 ` Linus Walleij
2018-09-21 10:25 ` [PATCH 7/9] dt-bindings: tegra186-gpio: Add wakeup parent support Thierry Reding
2018-09-21 10:37 ` Mikko Perttunen
2018-10-15 14:46 ` Rob Herring
2018-11-28 10:44 ` Thierry Reding
2018-09-21 10:25 ` [PATCH 8/9] gpio: tegra186: Rename flow variable to type Thierry Reding
2018-09-21 10:25 ` [PATCH 9/9] gpio: tegra186: Implement wake event support Thierry Reding
2018-09-25 8:48 ` [PATCH 0/9] Implement wake event support on Tegra186 and later Linus Walleij
2018-09-25 9:57 ` Thierry Reding
2018-09-25 17:16 ` Lina Iyer
2018-10-08 7:14 ` Stephen Boyd
2018-10-09 12:58 ` Marc Zyngier
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