Re: [PATCH] phy: omap-usb2: add explicit PHY comparator API

[Vinod Koul <vkoul@kernel.org>]

On 22-07-26, 08:36, Ivaylo Dimitrov wrote:
> The existing omap_usb2_set_comparator() API locates the OMAP USB2 PHY
> instance by calling usb_get_phy(USB_PHY_TYPE_USB2), assuming there is a
> single USB2 PHY registered in the system.
> 
> This assumption no longer holds on systems with multiple USB2 PHY
> providers. In such cases, the global lookup may return a different USB2
> PHY instance, causing the OMAP driver to perform an invalid container_of()
> conversion when accessing its private data.
> 
> Introduce omap_usb2_set_phy_comparator(), allowing callers to explicitly
> specify the OMAP USB2 PHY instance to associate with a phy_companion.
> The new helper validates that the supplied USB PHY is an OMAP USB2 PHY
> before accessing its private data.

Well the name can cause ambiguity with old API. Second I would like to
see users of this API as well

> 
> The existing omap_usb2_set_comparator() API is kept unchanged for
> existing users.
> 
> 
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> ---
>  drivers/phy/ti/phy-omap-usb2.c | 32 ++++++++++++++++++++++++++++++++
>  include/linux/phy/omap_usb.h   |  7 +++++++
>  2 files changed, 39 insertions(+)
> 
> diff --git a/drivers/phy/ti/phy-omap-usb2.c b/drivers/phy/ti/phy-omap-usb2.c
> index 1eb252604441..ac31b693fce7 100644
> --- a/drivers/phy/ti/phy-omap-usb2.c
> +++ b/drivers/phy/ti/phy-omap-usb2.c
> @@ -70,6 +70,8 @@ struct omap_usb {
>  
>  #define	phy_to_omapusb(x)	container_of((x), struct omap_usb, phy)
>  
> +static int omap_usb_set_host(struct usb_otg *otg, struct usb_bus *host);
> +
>  struct usb_phy_data {
>  	const char *label;
>  	u8 flags;
> @@ -113,6 +115,36 @@ int omap_usb2_set_comparator(struct phy_companion *comparator)
>  }
>  EXPORT_SYMBOL_GPL(omap_usb2_set_comparator);
>  
> +/**
> + * omap_usb2_set_phy_comparator() - associate a comparator with an OMAP USB2 PHY
> + *
> + * @omap_phy: OMAP USB2 PHY instance
> + * @comparator: companion PHY providing comparator operations
> + *
> + * The phy companion driver should call this API with the companion PHY
> + * implementation containing the callbacks required by @omap_phy.
> + *
> + * For use by phy companion drivers.
> + */
> +int omap_usb2_set_phy_comparator(struct usb_phy *omap_phy,
> +				 struct phy_companion *comparator)
> +{
> +	struct omap_usb	*phy;
> +
> +	if (!omap_phy)
> +		return -EINVAL;
> +
> +	if (WARN_ON(!omap_phy->otg ||
> +		    omap_phy->otg->set_host != omap_usb_set_host))
> +		return -EINVAL;
> +
> +	phy = phy_to_omapusb(omap_phy);
> +	phy->comparator = comparator;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(omap_usb2_set_phy_comparator);
> +
>  static int omap_usb_set_vbus(struct usb_otg *otg, bool enabled)
>  {
>  	struct omap_usb *phy = phy_to_omapusb(otg->usb_phy);
> diff --git a/include/linux/phy/omap_usb.h b/include/linux/phy/omap_usb.h
> index e23b52df93ec..96f9792c6ce6 100644
> --- a/include/linux/phy/omap_usb.h
> +++ b/include/linux/phy/omap_usb.h
> @@ -15,11 +15,18 @@
>  
>  #if defined(CONFIG_OMAP_USB2) || defined(CONFIG_OMAP_USB2_MODULE)
>  extern int omap_usb2_set_comparator(struct phy_companion *comparator);
> +extern int omap_usb2_set_phy_comparator(struct usb_phy *omap_phy,
> +					struct phy_companion *comparator);
>  #else
>  static inline int omap_usb2_set_comparator(struct phy_companion *comparator)
>  {
>  	return -ENODEV;
>  }
> +static inline int omap_usb2_set_phy_comparator(struct usb_phy *omap_phy,
> +					       struct phy_companion *comparator)
> +{
> +	return -ENODEV;
> +}
>  #endif
>  
>  #endif /* __DRIVERS_OMAP_USB_H */
> -- 
> 2.39.5

-- 
~Vinod

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