linux-kernel - Re: [PATCH v3 3/3] pinctrl: msm: Configure interrupts as input and gpio mode

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Message-ID: <20180827030641.GJ3048@tuxbook-pro>
Date:   Sun, 26 Aug 2018 20:06:41 -0700
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Stephen Boyd <swboyd@...omium.org>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
        linux-arm-msm@...r.kernel.org,
        Doug Anderson <dianders@...omium.org>
Subject: Re: [PATCH v3 3/3] pinctrl: msm: Configure interrupts as input and
 gpio mode

On Thu 16 Aug 13:06 PDT 2018, Stephen Boyd wrote:

> When requesting a gpio as an interrupt, we should make sure to mux the
> pin as the GPIO function and configure it to be an input so that various
> functions or output signals don't affect the interrupt state of the pin.
> So far, we've relied on pinmux configurations in DT to handle this, but
> let's explicitly configure this in the code so that DT implementers
> don't have to get this part right.
> 
> Cc: Bjorn Andersson <bjorn.andersson@...aro.org>
> Cc: Doug Anderson <dianders@...omium.org>
> Signed-off-by: Stephen Boyd <swboyd@...omium.org>

Reviewed-by: Bjorn Andersson <bjorn.andersson@...aro.org>

Regards,
Bjorn

> ---
>  drivers/pinctrl/qcom/pinctrl-msm.c | 37 ++++++++++++++++++++++++++++++
>  1 file changed, 37 insertions(+)
> 
> diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
> index 793504057ad0..defed34d32b0 100644
> --- a/drivers/pinctrl/qcom/pinctrl-msm.c
> +++ b/drivers/pinctrl/qcom/pinctrl-msm.c
> @@ -837,6 +837,41 @@ static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
>  	return 0;
>  }
>  
> +static int msm_gpio_irq_reqres(struct irq_data *d)
> +{
> +	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> +	struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
> +	int ret;
> +
> +	if (!try_module_get(gc->owner))
> +		return -ENODEV;
> +
> +	ret = msm_pinmux_request_gpio(pctrl->pctrl, NULL, d->hwirq);
> +	if (ret)
> +		goto out;
> +	msm_gpio_direction_input(gc, d->hwirq);
> +
> +	if (gpiochip_lock_as_irq(gc, d->hwirq)) {
> +		dev_err(gc->parent,
> +			"unable to lock HW IRQ %lu for IRQ\n",
> +			d->hwirq);
> +		ret = -EINVAL;
> +		goto out;
> +	}
> +	return 0;
> +out:
> +	module_put(gc->owner);
> +	return ret;
> +}
> +
> +static void msm_gpio_irq_relres(struct irq_data *d)
> +{
> +	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> +
> +	gpiochip_unlock_as_irq(gc, d->hwirq);
> +	module_put(gc->owner);
> +}
> +
>  static void msm_gpio_irq_handler(struct irq_desc *desc)
>  {
>  	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
> @@ -935,6 +970,8 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl)
>  	pctrl->irq_chip.irq_ack = msm_gpio_irq_ack;
>  	pctrl->irq_chip.irq_set_type = msm_gpio_irq_set_type;
>  	pctrl->irq_chip.irq_set_wake = msm_gpio_irq_set_wake;
> +	pctrl->irq_chip.irq_request_resources = msm_gpio_irq_reqres;
> +	pctrl->irq_chip.irq_release_resources = msm_gpio_irq_relres;
>  
>  	ret = gpiochip_add_data(&pctrl->chip, pctrl);
>  	if (ret) {
> -- 
> Sent by a computer through tubes
>