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Subject: Re: [PATCH v3 2/4] phy: Add API for devm_of_phy_optional_get_by_index
To:     Aswath Govindraju <a-govindraju@ti.com>
CC:     <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-phy@lists.infradead.org>, <linux-can@vger.kernel.org>,
        Vinod Koul <vkoul@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Marc Kleine-Budde <mkl@pengutronix.de>,
        Wolfgang Grandegger <wg@grandegger.com>,
        Lokesh Vutla <lokeshvutla@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Grygorii Strashko <grygorii.strashko@ti.com>
References: <20210415144947.4725-1-a-govindraju@ti.com>
 <20210415144947.4725-3-a-govindraju@ti.com>
From:   Kishon Vijay Abraham I <kishon@ti.com>
Message-ID: <c3baf0bc-e166-4aee-f4c7-e5915352ec82@ti.com>
Date:   Thu, 15 Apr 2021 20:30:26 +0530
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Hi Aswath,

On 15/04/21 8:19 pm, Aswath Govindraju wrote:
> Add API for devm_of_phy_optional_get_by_index, to obtain a reference to an
> optional phy by index.

Rob has posted a patch
http://lore.kernel.org/r/20210414135525.3535787-1-robh@kernel.org
that doesn't require consumers to get a phy by using string. Since your
usecase also requires only one PHY, that patch should be sufficient.
$patch could be deferred until a real use case comes.

Thanks
Kishon

> 
> Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
> ---
>  drivers/phy/phy-core.c  | 26 ++++++++++++++++++++++++++
>  include/linux/phy/phy.h |  2 ++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index ccb575b13777..bf06d4e0ede2 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -839,6 +839,32 @@ struct phy *devm_of_phy_get(struct device *dev, struct device_node *np,
>  }
>  EXPORT_SYMBOL_GPL(devm_of_phy_get);
>  
> +/**
> + * devm_of_phy_optional_get_by_index() - lookup and obtain a reference to an optional phy by index.
> + * @dev: device that requests this phy
> + * @np: node containing the phy
> + * @index: index of the phy
> + *
> + * Gets the phy using _of_phy_get(), then gets a refcount to it,
> + * and associates a device with it using devres. On driver detach,
> + * release function is invoked on the devres data, then,
> + * devres data is freed. This differs to devm_of_phy_get_by_index() in
> + * that if the phy does not exist, it is not considered an error and
> + * -ENODEV will not be returned. Instead the NULL phy is returned,
> + * which can be passed to all other phy consumer calls.
> + */
> +struct phy *devm_of_phy_optional_get_by_index(struct device *dev, struct device_node *np,
> +					      int index)
> +{
> +	struct phy *phy = devm_of_phy_get_by_index(dev, np, index);
> +
> +	if (PTR_ERR(phy) == -ENODEV)
> +		phy = NULL;
> +
> +	return phy;
> +}
> +EXPORT_SYMBOL_GPL(devm_of_phy_optional_get_by_index);
> +
>  /**
>   * devm_of_phy_get_by_index() - lookup and obtain a reference to a phy by index.
>   * @dev: device that requests this phy
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index f3286f4cd306..c5f32b4fadd6 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -253,6 +253,8 @@ struct phy *devm_of_phy_get(struct device *dev, struct device_node *np,
>  			    const char *con_id);
>  struct phy *devm_of_phy_get_by_index(struct device *dev, struct device_node *np,
>  				     int index);
> +struct phy *devm_of_phy_optional_get_by_index(struct device *dev, struct device_node *np,
> +					      int index);
>  void of_phy_put(struct phy *phy);
>  void phy_put(struct device *dev, struct phy *phy);
>  void devm_phy_put(struct device *dev, struct phy *phy);
>