Re: [PATCH RFC 1/2] dt-bindings: pinctl: amlogic,pinctrl-a4: Add gpio irq property

[Xianwei Zhao]

Hi Krzysztof,
   Thanks for your detailed review. After considering the feedback, I 
think this approach is not suitable, so I will drop this patch.

On 2026/6/15 13:32, Krzysztof Kozlowski wrote:
> On 15/06/2026 04:47, Xianwei Zhao wrote:
> > Hi Conor,
> >      Thanks for your review.
> >
> > On 2026/6/12 01:39, Conor Dooley wrote:
> > > Subject:
> > > Re: [PATCH RFC 1/2] dt-bindings: pinctl: amlogic,pinctrl-a4: Add gpio
> > > irq property
> > > From:
> > > Conor Dooley<conor@xxxxxxxxxx>
> > > Date:
> > > 2026/6/12 01:39
> > >
> > > To:
> > > xianwei.zhao@xxxxxxxxxxx
> > > CC:
> > > Linus Walleij<linusw@xxxxxxxxxx>, Rob Herring<robh@xxxxxxxxxx>,
> > > Krzysztof Kozlowski<krzk+dt@xxxxxxxxxx>, Conor Dooley
> > > <conor+dt@xxxxxxxxxx>, Neil Armstrong<neil.armstrong@xxxxxxxxxx>, Kevin
> > > Hilman<khilman@xxxxxxxxxxxx>, Jerome Brunet<jbrunet@xxxxxxxxxxxx>,
> > > Martin Blumenstingl<martin.blumenstingl@xxxxxxxxxxxxxx>,
> > > linux-amlogic@xxxxxxxxxxxxxxxxxxx,linux-gpio@xxxxxxxxxxxxxxx,
> > > devicetree@xxxxxxxxxxxxxxx,linux-kernel@xxxxxxxxxxxxxxx,
> > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > >
> > >
> > >
> > > On Thu, Jun 11, 2026 at 07:54:33AM +0000, Xianwei Zhao via B4 Relay wrote:
> > > > From: Xianwei Zhao<xianwei.zhao@xxxxxxxxxxx>
> > > >
> > > > Add the hw-irq property for each GPIO bank and enable interrupt-parent
> > > > for pinctrl so that gpiod_to_irq() can translate GPIO lines to IRQs.
> > > Uhhhhh, what? Why can't you just use the normal interrupts property?
> > The interrupt cannot be used directly because the GPIO bank only
> > provides an IRQ base, which does not have a one-to-one mapping with the
> > actual hardware interrupts.
> >
> > On Amlogic SoCs, GPIO interrupts are handled through a mux. Multiple
> > GPIO pins are mapped to a limited number of real interrupt sources. The
> > implementation can be found here:
> >
> > https://github.com/torvalds/linux/blob/master/drivers/irqchip/irq-meson-gpio.c
> >
> > To use a GPIO interrupt, an unused hardware interrupt must first be
> > allocated, and then the corresponding mux register must be configured.
> > This allocation and mapping are already implemented in the existing driver.
> >
> > In that driver, the mapping is performed dynamically rather than simply
> > calculating:
> >
> > irq = irq_start + gpio_offset
> >
> > If the interrupt is used directly, only the GPIO index can be obtained.
>
> If it is performed dynamically, then it is not suitable for DT.
>
> You still did not explain what hardware aspect exactly is described by
> "hw-irq".
>
>
>
> > The real interrupt number cannot be derived by simply adding an offset,
> > because the hardware interrupt must be allocated first. Pre-allocating
> > all interrupts during initialization would prevent later GPIOs from
> > obtaining available interrupt sources.
> >
> > Perhaps other names would be more appropriate here, such as "irq_start".
> >
> > > > Signed-off-by: Xianwei Zhao<xianwei.zhao@xxxxxxxxxxx>
> > > > ---
> Best regards,
> Krzysztof