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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Sat, 25 Sep 2021 01:48:00 +0200
Message-ID: <CACRpkdbUJF6VUPk9kCMPBvjeL3frJAbHq+h0-z7P-a1pSU+fiw@mail.gmail.com>
Subject: Re: [PATCH v3 1/2] gpio: mlxbf2: Introduce IRQ support
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Asmaa Mnebhi <asmaa@nvidia.com>,
        Andy Shevchenko <andy.shevchenko@gmail.com>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        netdev <netdev@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        "David S. Miller" <davem@davemloft.net>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        David Thompson <davthompson@nvidia.com>
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Precedence: bulk

On Fri, Sep 24, 2021 at 1:46 PM Andrew Lunn <andrew@lunn.ch> wrote:

> > +static int
> > +mlxbf2_gpio_irq_set_type(struct irq_data *irqd, unsigned int type)
> > +{
> > +     struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
> > +     struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc);
> > +     int offset = irqd_to_hwirq(irqd);
> > +     unsigned long flags;
> > +     bool fall = false;
> > +     bool rise = false;
> > +     u32 val;
> > +
> > +     switch (type & IRQ_TYPE_SENSE_MASK) {
> > +     case IRQ_TYPE_EDGE_BOTH:
> > +     case IRQ_TYPE_LEVEL_MASK:
> > +             fall = true;
> > +             rise = true;
> > +             break;
> > +     case IRQ_TYPE_EDGE_RISING:
> > +     case IRQ_TYPE_LEVEL_HIGH:
> > +             rise = true;
> > +             break;
> > +     case IRQ_TYPE_EDGE_FALLING:
> > +     case IRQ_TYPE_LEVEL_LOW:
> > +             fall = true;
> > +             break;
> > +     default:
> > +             return -EINVAL;
> > +     }
>
> I'm still not convinced this is correct. Rising edge is different to
> high. Rising edge only ever interrupts once, level keeps interrupting
> until the source is cleared. You cannot store the four different
> options in two bits.
>
> Linus, have you seen anything like this before?

No, and I agree it looks weird.

There must be some explanation, what does the datasheet say?

Yours,
Linus Walleij