Date:   Mon, 22 Nov 2021 14:30:49 +0100
From:   Marc Kleine-Budde <mkl@pengutronix.de>
To:     Aswath Govindraju <a-govindraju@ti.com>
Cc:     Nishanth Menon <nm@ti.com>, Vignesh Raghavendra <vigneshr@ti.com>,
        Peter Rosin <peda@axentia.se>,
        Rob Herring <robh+dt@kernel.org>,
        Wolfgang Grandegger <wg@grandegger.com>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Vinod Koul <vkoul@kernel.org>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-can@vger.kernel.org,
        linux-phy@lists.infradead.org
Subject: Re: [PATCH RFC v2 4/4] phy: phy-can-transceiver: Add support for
 setting mux
Message-ID: <20211122133049.mlbshta6ksck2ngo@pengutronix.de>
References: <20211122125624.6431-1-a-govindraju@ti.com>
 <20211122125624.6431-5-a-govindraju@ti.com>
 <20211122131221.i3djuarw2ae5lbdk@pengutronix.de>
 <47a0f27f-4d44-cc8f-f2ef-0919f38843bf@ti.com>
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On 22.11.2021 18:50:00, Aswath Govindraju wrote:
> > What about adding a devm_mux_control_get_optional(), which doesn't
> > return a -ENODEV but a NULL pointer if the device doesn't exist?
> >=20
>=20
> I tried adding it in the following manner,
>=20
> +/**
> + * devm_mux_control_optional_get() - Optionally get the mux-control for a
> + *                                  device, with resource management.
> + * @dev: The device that needs a mux-control.
> + * @mux_name: The name identifying the mux-control.
> + *
> + * This differs from devm_mux_control_get in that if the mux does not
> + * exist, it is not considered an error and -ENODEV will not be
> + * returned. Instead the NULL is returned.
> + *
> + * Return: Pointer to the mux-control, or an ERR_PTR with a negative err=
no.
> + */
> +struct mux_control *devm_mux_control_optional_get(struct device *dev,
> +                                                 const char *mux_name)
> +{
> +       struct mux_control *mux_ctrl;
> +
> +       mux_ctrl =3D devm_mux_control_get(dev, mux_name);
> +       if (PTR_ERR(mux_ctrl) =3D=3D -ENOENT)
> +                mux_ctrl =3D NULL;
> +
> +       return mux_ctrl;
> +}
> +EXPORT_SYMBOL_GPL(devm_mux_control_optional_get);
> +
>=20
> However the issue is that there is a print in mux_control_get()
>  dev_err(dev, "%pOF: failed to get mux-control %s(%i)\n",
>=20
> which is getting printed, whenever mux-controls property is not found.
> Therefore, I was not sure about how to go about this issue and did not
> implement it.

Ok, this would require more tweaking in the mux layer. Then leave it as
is.

regards,
Marc

--=20
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |

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