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Subject: Re: [PATCH] pinctrl: stm32: check irq controller availability at
 probe
To:     Fabien Dessenne <fabien.dessenne@st.com>,
        Linus Walleij <linus.walleij@linaro.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Benjamin Gaignard <benjamin.gaignard@linaro.org>,
        <linux-gpio@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
References: <1556093324-1008-1-git-send-email-fabien.dessenne@st.com>
From:   Alexandre Torgue <alexandre.torgue@st.com>
Message-ID: <8d65f99f-0874-8012-5e44-3e579cb1f878@st.com>
Date:   Wed, 24 Apr 2019 11:29:48 +0200
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On 4/24/19 10:08 AM, Fabien Dessenne wrote:
> It is not guaranteed that the IRQ controller driver is probed before
> the pin controller driver gets probed.
> Considering this, check for the irq domain availability during probe
> and return EPROBE_DEFER if needed.
> 
> Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
> ---


Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>

>   drivers/pinctrl/stm32/pinctrl-stm32.c | 37 +++++++++++++++++++++++++----------
>   1 file changed, 27 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
> index 0aebc31..2317ccf 100644
> --- a/drivers/pinctrl/stm32/pinctrl-stm32.c
> +++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
> @@ -1122,23 +1122,35 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl,
>   	return 0;
>   }
>   
> +static struct irq_domain *stm32_pctrl_get_irq_domain(struct device_node *np)
> +{
> +	struct device_node *parent;
> +	struct irq_domain *domain;
> +
> +	if (!of_find_property(np, "interrupt-parent", NULL))
> +		return NULL;
> +
> +	parent = of_irq_find_parent(np);
> +	if (!parent)
> +		return ERR_PTR(-ENXIO);
> +
> +	domain = irq_find_host(parent);
> +	if (!domain)
> +		/* domain not registered yet */
> +		return ERR_PTR(-EPROBE_DEFER);
> +
> +	return domain;
> +}
> +
>   static int stm32_pctrl_dt_setup_irq(struct platform_device *pdev,
>   			   struct stm32_pinctrl *pctl)
>   {
> -	struct device_node *np = pdev->dev.of_node, *parent;
> +	struct device_node *np = pdev->dev.of_node;
>   	struct device *dev = &pdev->dev;
>   	struct regmap *rm;
>   	int offset, ret, i;
>   	int mask, mask_width;
>   
> -	parent = of_irq_find_parent(np);
> -	if (!parent)
> -		return -ENXIO;
> -
> -	pctl->domain = irq_find_host(parent);
> -	if (!pctl->domain)
> -		return -ENXIO;
> -
>   	pctl->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
>   	if (IS_ERR(pctl->regmap))
>   		return PTR_ERR(pctl->regmap);
> @@ -1264,6 +1276,11 @@ int stm32_pctl_probe(struct platform_device *pdev)
>   
>   	platform_set_drvdata(pdev, pctl);
>   
> +	/* check for IRQ controller (may require deferred probe) */
> +	pctl->domain = stm32_pctrl_get_irq_domain(np);
> +	if (IS_ERR(pctl->domain))
> +		return PTR_ERR(pctl->domain);
> +
>   	/* hwspinlock is optional */
>   	hwlock_id = of_hwspin_lock_get_id(pdev->dev.of_node, 0);
>   	if (hwlock_id < 0) {
> @@ -1294,7 +1311,7 @@ int stm32_pctl_probe(struct platform_device *pdev)
>   		return -EINVAL;
>   	}
>   
> -	if (of_find_property(np, "interrupt-parent", NULL)) {
> +	if (pctl->domain) {
>   		ret = stm32_pctrl_dt_setup_irq(pdev, pctl);
>   		if (ret)
>   			return ret;
>