linux-kernel - Re: [PATCH 1/1] pinctrl: stmfx: add irq_request/release

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Date:   Sat, 5 Oct 2019 18:49:37 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Amelie Delaunay <amelie.delaunay@...com>
Cc:     Alexandre Torgue <alexandre.torgue@...com>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        linux-stm32@...md-mailman.stormreply.com
Subject: Re: [PATCH 1/1] pinctrl: stmfx: add irq_request/release_resources callbacks

On Fri, Oct 4, 2019 at 2:29 PM Amelie Delaunay <amelie.delaunay@...com> wrote:

> When an STMFX IO is used as interrupt through the interrupt-controller
> binding, the STMFX driver should configure this IO as input. Default
> value of STMFX IO direction is input, but if the IO is used as output
> before the interrupt use, it will not work without these callbacks.
>
> Signed-off-by: Amelie Delaunay <amelie.delaunay@...com>

OK I see what you want to achieve.

> +static int stmfx_gpio_irq_request_resources(struct irq_data *data)
> +{
> +       struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(data);
> +       struct stmfx_pinctrl *pctl = gpiochip_get_data(gpio_chip);
> +       int ret;
> +
> +       ret = stmfx_gpio_direction_input(&pctl->gpio_chip, data->hwirq);
> +       if (ret)
> +               return ret;
> +
> +       ret = gpiochip_lock_as_irq(&pctl->gpio_chip, data->hwirq);
> +       if (ret) {
> +               dev_err(pctl->dev, "Unable to lock gpio %lu as IRQ: %d\n",
> +                       data->hwirq, ret);
> +               return ret;
> +       }
> +
> +       return 0;
> +}

Just call gpiochip_reqres_irq() instead of calling the lock etc
explicitly.

> +static void stmfx_gpio_irq_release_resources(struct irq_data *data)
> +{
> +       struct gpio_chip *gpio_chip = irq_data_get_irq_chip_data(data);
> +       struct stmfx_pinctrl *pctl = gpiochip_get_data(gpio_chip);
> +
> +       gpiochip_unlock_as_irq(&pctl->gpio_chip, data->hwirq);
> +}

Just call gpiochip_relres_irq()

But all this duplicated a lot of code from the core which is not so nice.

> @@ -678,6 +706,8 @@ static int stmfx_pinctrl_probe(struct platform_device *pdev)
>         pctl->irq_chip.irq_set_type = stmfx_pinctrl_irq_set_type;
>         pctl->irq_chip.irq_bus_lock = stmfx_pinctrl_irq_bus_lock;
>         pctl->irq_chip.irq_bus_sync_unlock = stmfx_pinctrl_irq_bus_sync_unlock;
> +       pctl->irq_chip.irq_request_resources = stmfx_gpio_irq_request_resources;
> +       pctl->irq_chip.irq_release_resources = stmfx_gpio_irq_release_resources;

What about just adding

pctl->irq_chip.irq_enable and do stmfx_gpio_direction_input()
in that callback instead? gpiolib will helpfully wrap it.

Yours,
Linus Walleij