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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Tue, 8 Dec 2020 16:19:07 +0200
Message-ID: <CAHp75VfMKmJ074R2-04be0Ag6OuKcY=_xhhbRKsL2D0H8hZZLg@mail.gmail.com>
Subject: Re: [RFC PATCH] RFC: drivers: gpio: helper for generic pin IRQ handling
To:     "Enrico Weigelt, metux IT consult" <info@metux.net>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        William Breathitt Gray <vilhelm.gray@gmail.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        joyce.ooi@intel.com, Andrew Jeffery <andrew@aj.id.au>,
        Hoan Tran <hoan@os.amperecomputing.com>,
        Serge Semin <fancer.lancer@gmail.com>, orsonzhai@gmail.com,
        baolin.wang7@gmail.com, zhang.lyra@gmail.com,
        Andy Shevchenko <andy@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Grygorii Strashko <grygorii.strashko@ti.com>,
        Santosh Shilimkar <ssantosh@kernel.org>,
        Kevin Hilman <khilman@kernel.org>,
        Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        Jun Nie <jun.nie@linaro.org>, Shawn Guo <shawnguo@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Linux OMAP Mailing List <linux-omap@vger.kernel.org>
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On Tue, Dec 8, 2020 at 4:14 PM Enrico Weigelt, metux IT consult
<info@metux.net> wrote:
>
> Many gpio drivers already use gpiolib's builtin irqchip handling
> (CONFIG_GPIOLIB_IRQCHIP), but still has some boilerplate for retrieving
> the actual Linux IRQ number and calling into the generic handler.
> That boilerplate can be reduced by moving that into a helper function.
>
> This is an RFC patch to outline how that could be done. Note: it's
> completely untested yet.
>
> Several drivers still have their completely IRQ own implementation and
> thus can't be converted yet. Some of them perhaps could be changed to
> store their irq domain in the struct gpio, so the new helper could
> also be used for those.
>
> Having all GPIO drivers doing their IRQ management entirely through the
> GPIO subsystem (eg. never calling generic_handle_irq() and using the buil=
tin
> IRQ handling) would also allow a more direct (eg. callback-based) pin cha=
nge
> notification for GPIO consumers, that doesn't involve registering them as
> generic IRQ handlers.
>
> Further reduction of boilerplate could be achieved by additional helpers
> for common patterns like for_each_set_bit() loops on irq masks.

Have you able to test them all?
As the PCA953x case showed us this is not so simple, besides the name
which sucks =E2=80=94 we don't *raise* and IRQ we *handle* it.

NAK.

--=20
With Best Regards,
Andy Shevchenko