[Linux-stm32] [PATCH] phy: core: Add consumer device link support

[Kishon Vijay Abraham I]

On Mon, Nov 04, 2019 at 03:37:13PM +0100, Alexandre Torgue wrote:
> In order to enforce suspend/resume ordering, this commit creates link
> between phy consumers and phy devices. This link avoids to suspend phy
> before phy consumers.
> 
> Signed-off-by: Alexandre Torgue <alexandre.torgue at st.com>
>
merged now, Thanks!

-Kishon

> ---
> 
> Hi,
> 
> To manage device_link in phy-core I had to "balance" get and put APIs a bit
> more. Fot this reason, you'll find updates in Renesas usbhs rcar and rza drivers
> as phy API changes.
> 
> Regards
> Alex
> 
> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
> index b04f4fe85ac2..8dfb4868c8c3 100644
> --- a/drivers/phy/phy-core.c
> +++ b/drivers/phy/phy-core.c
> @@ -29,7 +29,7 @@ static void devm_phy_release(struct device *dev, void *res)
>  {
>  	struct phy *phy = *(struct phy **)res;
>  
> -	phy_put(phy);
> +	phy_put(dev, phy);
>  }
>  
>  static void devm_phy_provider_release(struct device *dev, void *res)
> @@ -566,12 +566,12 @@ struct phy *of_phy_get(struct device_node *np, const char *con_id)
>  EXPORT_SYMBOL_GPL(of_phy_get);
>  
>  /**
> - * phy_put() - release the PHY
> - * @phy: the phy returned by phy_get()
> + * of_phy_put() - release the PHY
> + * @phy: the phy returned by of_phy_get()
>   *
> - * Releases a refcount the caller received from phy_get().
> + * Releases a refcount the caller received from of_phy_get().
>   */
> -void phy_put(struct phy *phy)
> +void of_phy_put(struct phy *phy)
>  {
>  	if (!phy || IS_ERR(phy))
>  		return;
> @@ -584,6 +584,20 @@ void phy_put(struct phy *phy)
>  	module_put(phy->ops->owner);
>  	put_device(&phy->dev);
>  }
> +EXPORT_SYMBOL_GPL(of_phy_put);
> +
> +/**
> + * phy_put() - release the PHY
> + * @dev: device that wants to release this phy
> + * @phy: the phy returned by phy_get()
> + *
> + * Releases a refcount the caller received from phy_get().
> + */
> +void phy_put(struct device *dev, struct phy *phy)
> +{
> +	device_link_remove(dev, &phy->dev);
> +	of_phy_put(phy);
> +}
>  EXPORT_SYMBOL_GPL(phy_put);
>  
>  /**
> @@ -651,6 +665,7 @@ struct phy *phy_get(struct device *dev, const char *string)
>  {
>  	int index = 0;
>  	struct phy *phy;
> +	struct device_link *link;
>  
>  	if (string == NULL) {
>  		dev_WARN(dev, "missing string\n");
> @@ -672,6 +687,13 @@ struct phy *phy_get(struct device *dev, const char *string)
>  
>  	get_device(&phy->dev);
>  
> +	link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
> +	if (!link) {
> +		dev_err(dev, "failed to create device link to %s\n",
> +			dev_name(phy->dev.parent));
> +		return ERR_PTR(-EINVAL);
> +	}
> +
>  	return phy;
>  }
>  EXPORT_SYMBOL_GPL(phy_get);
> @@ -765,6 +787,7 @@ struct phy *devm_of_phy_get(struct device *dev, struct device_node *np,
>  			    const char *con_id)
>  {
>  	struct phy **ptr, *phy;
> +	struct device_link *link;
>  
>  	ptr = devres_alloc(devm_phy_release, sizeof(*ptr), GFP_KERNEL);
>  	if (!ptr)
> @@ -778,6 +801,13 @@ struct phy *devm_of_phy_get(struct device *dev, struct device_node *np,
>  		devres_free(ptr);
>  	}
>  
> +	link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
> +	if (!link) {
> +		dev_err(dev, "failed to create device link to %s\n",
> +			dev_name(phy->dev.parent));
> +		return ERR_PTR(-EINVAL);
> +	}
> +
>  	return phy;
>  }
>  EXPORT_SYMBOL_GPL(devm_of_phy_get);
> @@ -798,6 +828,7 @@ struct phy *devm_of_phy_get_by_index(struct device *dev, struct device_node *np,
>  				     int index)
>  {
>  	struct phy **ptr, *phy;
> +	struct device_link *link;
>  
>  	ptr = devres_alloc(devm_phy_release, sizeof(*ptr), GFP_KERNEL);
>  	if (!ptr)
> @@ -819,6 +850,13 @@ struct phy *devm_of_phy_get_by_index(struct device *dev, struct device_node *np,
>  	*ptr = phy;
>  	devres_add(dev, ptr);
>  
> +	link = device_link_add(dev, &phy->dev, DL_FLAG_STATELESS);
> +	if (!link) {
> +		dev_err(dev, "failed to create device link to %s\n",
> +			dev_name(phy->dev.parent));
> +		return ERR_PTR(-EINVAL);
> +	}
> +
>  	return phy;
>  }
>  EXPORT_SYMBOL_GPL(devm_of_phy_get_by_index);
> diff --git a/drivers/usb/renesas_usbhs/rcar2.c b/drivers/usb/renesas_usbhs/rcar2.c
> index 440d213e1749..791908f8cf73 100644
> --- a/drivers/usb/renesas_usbhs/rcar2.c
> +++ b/drivers/usb/renesas_usbhs/rcar2.c
> @@ -34,7 +34,7 @@ static int usbhs_rcar2_hardware_exit(struct platform_device *pdev)
>  	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
>  
>  	if (priv->phy) {
> -		phy_put(priv->phy);
> +		phy_put(&pdev->dev, priv->phy);
>  		priv->phy = NULL;
>  	}
>  
> diff --git a/drivers/usb/renesas_usbhs/rza2.c b/drivers/usb/renesas_usbhs/rza2.c
> index 021749594389..3eed3334a17f 100644
> --- a/drivers/usb/renesas_usbhs/rza2.c
> +++ b/drivers/usb/renesas_usbhs/rza2.c
> @@ -29,7 +29,7 @@ static int usbhs_rza2_hardware_exit(struct platform_device *pdev)
>  {
>  	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
>  
> -	phy_put(priv->phy);
> +	phy_put(&pdev->dev, priv->phy);
>  	priv->phy = NULL;
>  
>  	return 0;
> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
> index 56d3a100006a..19eddd64c8f6 100644
> --- a/include/linux/phy/phy.h
> +++ b/include/linux/phy/phy.h
> @@ -234,7 +234,8 @@ 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);
> -void phy_put(struct phy *phy);
> +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);
>  struct phy *of_phy_get(struct device_node *np, const char *con_id);
>  struct phy *of_phy_simple_xlate(struct device *dev,
> @@ -419,7 +420,11 @@ static inline struct phy *devm_of_phy_get_by_index(struct device *dev,
>  	return ERR_PTR(-ENOSYS);
>  }
>  
> -static inline void phy_put(struct phy *phy)
> +static inline void of_phy_put(struct phy *phy)
> +{
> +}
> +
> +static inline void phy_put(struct device *dev, struct phy *phy)
>  {
>  }
>  
> -- 
> 2.17.1
>