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References: <1585128694-13881-1-git-send-email-hanks.chen@mediatek.com> <1585128694-13881-4-git-send-email-hanks.chen@mediatek.com>
In-Reply-To: <1585128694-13881-4-git-send-email-hanks.chen@mediatek.com>
From:   Sean Wang <sean.wang@kernel.org>
Date:   Thu, 2 Apr 2020 14:33:01 -0700
Message-ID: <CAGp9LzpaC5opt9=BDUbR6tdr75F8cUxZc9nydJmNwoyq15x7hg@mail.gmail.com>
Subject: Re: [PATCH v5 3/6] pinctrl: mediatek: avoid virtual gpio trying to
 set reg
To:     Hanks Chen <hanks.chen@mediatek.com>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Andy Teng <andy.teng@mediatek.com>,
        lkml <linux-kernel@vger.kernel.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>, devicetree@vger.kernel.org,
        wsd_upstream@mediatek.com, Mars Cheng <mars.cheng@mediatek.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Hi Hanks,

On Wed, Mar 25, 2020 at 2:31 AM Hanks Chen <hanks.chen@mediatek.com> wrote:
>
> for virtual gpios, they should not do reg setting and
> should behave as expected for eint function.
>
> Signed-off-by: Hanks Chen <hanks.chen@mediatek.com>
> Signed-off-by: Mars Cheng <mars.cheng@mediatek.com>
> ---
>  drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c |   28 ++++++++++++++++++++++
>  drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h |    1 +
>  drivers/pinctrl/mediatek/pinctrl-paris.c         |    7 ++++++
>  3 files changed, 36 insertions(+)
>
> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> index 20e1c89..087d233 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
> @@ -226,6 +226,31 @@ static int mtk_xt_find_eint_num(struct mtk_pinctrl *hw, unsigned long eint_n)
>         return EINT_NA;
>  }
>
> +/*
> + * Virtual GPIO only used inside SOC and not being exported to outside SOC.
> + * Some modules use virtual GPIO as eint (e.g. pmif or usb).
> + * In MTK platform, external interrupt (EINT) and GPIO is 1-1 mapping
> + * and we can set GPIO as eint.
> + * But some modules use specific eint which doesn't have real GPIO pin.
> + * So we use virtual GPIO to map it.
> + */
> +
> +bool mtk_is_virt_gpio(struct mtk_pinctrl *hw, unsigned int gpio_n)
> +{
> +       const struct mtk_pin_desc *desc;
> +       bool virt_gpio = false;
> +
> +       if (gpio_n >= hw->soc->npins)
> +               return virt_gpio;

gpio_n should always be less than hw-> soc-> npins, right? If so, we
can delete the condition from here.

> +
> +       desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio_n];
> +
> +       if (desc->funcs && !desc->funcs[desc->eint.eint_m].name)
> +               virt_gpio = true;
> +
> +       return virt_gpio;
> +}
> +
>  static int mtk_xt_get_gpio_n(void *data, unsigned long eint_n,
>                              unsigned int *gpio_n,
>                              struct gpio_chip **gpio_chip)
> @@ -278,6 +303,9 @@ static int mtk_xt_set_gpio_as_eint(void *data, unsigned long eint_n)
>         if (err)
>                 return err;
>
> +       if (mtk_is_virt_gpio(hw, gpio_n))
> +               return 0;
> +
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio_n];
>
>         err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_MODE,
> diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
> index 1b7da42..cda1c7a0 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
> +++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
> @@ -299,4 +299,5 @@ int mtk_pinconf_adv_drive_set(struct mtk_pinctrl *hw,
>  int mtk_pinconf_adv_drive_get(struct mtk_pinctrl *hw,
>                               const struct mtk_pin_desc *desc, u32 *val);
>
> +bool mtk_is_virt_gpio(struct mtk_pinctrl *hw, unsigned int gpio_n);
>  #endif /* __PINCTRL_MTK_COMMON_V2_H */
> diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
> index 923264d..7fba76d 100644
> --- a/drivers/pinctrl/mediatek/pinctrl-paris.c
> +++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
> @@ -693,6 +693,13 @@ static int mtk_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
>         const struct mtk_pin_desc *desc;
>         int value, err;
>
> +       /*
> +        * "Virtual" GPIOs are always and only used for interrupts
> +        * Since they are only used for interrupts, they are always inputs
> +        */
> +       if (mtk_is_virt_gpio(hw, gpio))
> +               return 1;
> +
>         desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];
>
>         err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DIR, &value);
> --
> 1.7.9.5