linux-kernel - Re: [PATCH v3 1/2] gpio: sch: Add edge event support

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Message-ID: <20191122111219.GW32742@smile.fi.intel.com>
Date:   Fri, 22 Nov 2019 13:12:19 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Jan Kiszka <jan.kiszka@...mens.com>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-gpio@...r.kernel.org,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>
Subject: Re: [PATCH v3 1/2] gpio: sch: Add edge event support

On Wed, Nov 20, 2019 at 08:20:13PM +0100, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@...mens.com>
> 
> Add the required infrastructure consisting of an irq_chip_generic with
> its irq_chip_type callbacks to enable and report edge events of the pins
> to the gpio core. The actual hook-up of the event interrupt will happen
> separately.

> +static int sch_irq_type(struct irq_data *d, unsigned int type)
> +{
> +	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +	struct sch_gpio *sch = gc->private;
> +	unsigned int gpio_num = d->irq - sch->irq_base;
> +	unsigned long flags;
> +	int rising = 0;
> +	int falling = 0;
> +
> +	switch (type & IRQ_TYPE_SENSE_MASK) {
> +	case IRQ_TYPE_EDGE_RISING:
> +		rising = 1;
> +		break;
> +	case IRQ_TYPE_EDGE_FALLING:
> +		falling = 1;
> +		break;
> +	case IRQ_TYPE_EDGE_BOTH:
> +		rising = 1;
> +		falling = 1;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	spin_lock_irqsave(&sch->lock, flags);
> +	sch_gpio_reg_set(sch, gpio_num, GTPE, rising);
> +	sch_gpio_reg_set(sch, gpio_num, GTNE, falling);
> +	spin_unlock_irqrestore(&sch->lock, flags);

Won't we need to set up IRQ handler here and use handle_bad_irq() during
initialization phase?

> +
> +	return 0;
> +}

> +	irq_base = devm_irq_alloc_descs(&pdev->dev, -1, 0, sch->chip.ngpio,
> +					NUMA_NO_NODE);
> +	if (irq_base < 0)
> +		return irq_base;
> +	sch->irq_base = irq_base;
> +
> +	gc = devm_irq_alloc_generic_chip(&pdev->dev, "sch_gpio", 1, irq_base,
> +					 NULL, handle_simple_irq);
> +	if (!gc)
> +		return -ENOMEM;
> +
> +	gc->private = sch;
> +	ct = gc->chip_types;
> +
> +	ct->chip.irq_mask = sch_irq_mask;
> +	ct->chip.irq_unmask = sch_irq_unmask;
> +	ct->chip.irq_set_type = sch_irq_type;
> +
> +	ret = devm_irq_setup_generic_chip(&pdev->dev, gc,
> +					  IRQ_MSK(sch->chip.ngpio),
> +					  0, IRQ_NOREQUEST | IRQ_NOPROBE, 0);
> +	if (ret)
> +		return ret;

Shan't we do this in the (similar) way how it's done in pinctrl-cherryview.c
driver? (Keep in mind later patches which are going to be v5.5)

-- 
With Best Regards,
Andy Shevchenko