[PATCH 1/2] usb: roles: add helper usb_role_string()

[Heikki Krogerus]

On Tue, May 25, 2021 at 04:53:05PM +0800, Chunfeng Yun wrote:
> Introduces usb_role_string() function, which returns a
> human-readable name of provided usb role, it's useful to
> make the log readable.
> 
> Signed-off-by: Chunfeng Yun <chunfeng.yun at mediatek.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus at linux.intel.com>

> ---
>  drivers/usb/roles/class.c | 9 +++++++++
>  include/linux/usb/role.h  | 6 ++++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
> index 33b637d0d8d9..dfaed7eee94f 100644
> --- a/drivers/usb/roles/class.c
> +++ b/drivers/usb/roles/class.c
> @@ -214,6 +214,15 @@ static const char * const usb_roles[] = {
>  	[USB_ROLE_DEVICE]	= "device",
>  };
>  
> +const char *usb_role_string(enum usb_role role)
> +{
> +	if (role < 0 || role >= ARRAY_SIZE(usb_roles))
> +		return "unknown";
> +
> +	return usb_roles[role];
> +}
> +EXPORT_SYMBOL_GPL(usb_role_string);
> +
>  static ssize_t
>  role_show(struct device *dev, struct device_attribute *attr, char *buf)
>  {
> diff --git a/include/linux/usb/role.h b/include/linux/usb/role.h
> index 0164fed31b06..031f148ab373 100644
> --- a/include/linux/usb/role.h
> +++ b/include/linux/usb/role.h
> @@ -65,6 +65,7 @@ void usb_role_switch_unregister(struct usb_role_switch *sw);
>  
>  void usb_role_switch_set_drvdata(struct usb_role_switch *sw, void *data);
>  void *usb_role_switch_get_drvdata(struct usb_role_switch *sw);
> +const char *usb_role_string(enum usb_role role);
>  #else
>  static inline int usb_role_switch_set_role(struct usb_role_switch *sw,
>  		enum usb_role role)
> @@ -109,6 +110,11 @@ static inline void *usb_role_switch_get_drvdata(struct usb_role_switch *sw)
>  	return NULL;
>  }
>  
> +static inline const char *usb_role_string(enum usb_role role)
> +{
> +	return "unknown";
> +}
> +
>  #endif
>  
>  #endif /* __LINUX_USB_ROLE_H */
> -- 
> 2.18.0

-- 
heikki