linux-kernel - Re: [PATCH v3 06/16] irqchip: add sl28cpld interrupt controller support

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Date:   Mon, 27 Apr 2020 19:40:11 +0200
From:   Michael Walle <michael@...le.cc>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        linux-gpio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-hwmon@...r.kernel.org,
        linux-pwm@...r.kernel.org, linux-watchdog@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Rob Herring <robh+dt@...nel.org>,
        Jean Delvare <jdelvare@...e.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Lee Jones <lee.jones@...aro.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Uwe Kleine-König <u.kleine-koenig@...gutronix.de>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Shawn Guo <shawnguo@...nel.org>, Li Yang <leoyang.li@....com>,
        Jason Cooper <jason@...edaemon.net>,
        Marc Zyngier <maz@...nel.org>, Mark Brown <broonie@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: [PATCH v3 06/16] irqchip: add sl28cpld interrupt controller
 support

Hi Thomas,

thanks for the review.

Am 2020-04-27 13:40, schrieb Thomas Gleixner:
> Michael Walle <michael@...le.cc> writes:
> 
>> This patch adds support for the interrupt controller inside the sl28
> 
> git grep 'This patch' Documentation/process/

ok.

> 
>> CPLD management controller.
>> 
>> +static int sl28cpld_intc_probe(struct platform_device *pdev)
>> +{
>> +	struct sl28cpld_intc *irqchip;
>> +	struct resource *res;
>> +	unsigned int irq;
>> +	int ret;
>> +
>> +	if (!pdev->dev.parent)
>> +		return -ENODEV;
>> +
>> +	irqchip = devm_kzalloc(&pdev->dev, sizeof(*irqchip), GFP_KERNEL);
>> +	if (!irqchip)
>> +		return -ENOMEM;
>> +
>> +	irqchip->regmap = dev_get_regmap(pdev->dev.parent, NULL);
>> +	if (!irqchip->regmap)
>> +		return -ENODEV;
>> +
>> +	irq = platform_get_irq(pdev, 0);
>> +	if (irq < 0)
>> +		return irq;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
>> +	if (!res)
>> +		return -EINVAL;
>> +
>> +	irqchip->chip.name = "sl28cpld-intc";
>> +	irqchip->chip.irqs = sl28cpld_irqs;
>> +	irqchip->chip.num_irqs = ARRAY_SIZE(sl28cpld_irqs);
>> +	irqchip->chip.num_regs = 1;
>> +	irqchip->chip.status_base = res->start + INTC_IP;
>> +	irqchip->chip.mask_base = res->start + INTC_IE;
>> +	irqchip->chip.mask_invert = true,
>> +	irqchip->chip.ack_base = res->start + INTC_IP;
>> +
>> +	ret = devm_regmap_add_irq_chip(&pdev->dev, irqchip->regmap, irq,
>> +				       IRQF_SHARED | IRQF_ONESHOT, 0,
> 
> What's the point of IRQF_SHARED | IRQF_ONESHOT here?

IRQF_SHARED because this interrupt is shared with all the blocks
which can generate interrupts, i.e. the GPIO contollers.

IRQF_ONESHOT, because its is a threaded interrupt with no primary
handler. But I just noticed, that regmap-irq will also set the
IRQF_ONESHOT. But that the commit 09cadf6e088b ("regmap-irq:
set IRQF_ONESHOT flag to ensure IRQ request") reads like it is
just there to be sure. So I don't know if it should also be set
here.

-michael

> 
>> +				       &irqchip->chip, &irqchip->irq_data);
> 
> Thanks,
> 
>         tglx