Re: [PATCH v4 1/5] usb: gadget: Properly configure the device for remote wakeup

[Thinh Nguyen]

On Mon, Feb 13, 2023, Elson Roy Serrao wrote:
> The wakeup bit in the bmAttributes field indicates whether the device
> is configured for remote wakeup. But this field should be allowed to
> set only if the UDC supports such wakeup mechanism. So configure this
> field based on UDC capability. Also inform the UDC whether the device
> is configured for remote wakeup by implementing a gadget op.
> 
> Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
> ---
>  drivers/usb/gadget/composite.c | 18 ++++++++++++++++++
>  drivers/usb/gadget/configfs.c  |  3 +++
>  drivers/usb/gadget/udc/core.c  | 27 +++++++++++++++++++++++++++
>  drivers/usb/gadget/udc/trace.h |  5 +++++
>  include/linux/usb/composite.h  |  2 ++
>  include/linux/usb/gadget.h     |  8 ++++++++
>  6 files changed, 63 insertions(+)
> 
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index fa7dd6c..a37a8f4 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -513,6 +513,19 @@ static u8 encode_bMaxPower(enum usb_device_speed speed,
>  		return min(val, 900U) / 8;
>  }
>  
> +void check_remote_wakeup_config(struct usb_gadget *g,
> +				struct usb_configuration *c)
> +{
> +	if (USB_CONFIG_ATT_WAKEUP & c->bmAttributes) {
> +		/* Reset the rw bit if gadget is not capable of it */
> +		if (!g->wakeup_capable && g->ops->set_remote_wakeup) {
> +			WARN(c->cdev, "Clearing wakeup bit for config c.%d\n",
> +			     c->bConfigurationValue);
> +			c->bmAttributes &= ~USB_CONFIG_ATT_WAKEUP;
> +		}
> +	}
> +}
> +
>  static int config_buf(struct usb_configuration *config,
>  		enum usb_device_speed speed, void *buf, u8 type)
>  {
> @@ -1000,6 +1013,11 @@ static int set_config(struct usb_composite_dev *cdev,
>  	else
>  		usb_gadget_clear_selfpowered(gadget);
>  
> +	if (USB_CONFIG_ATT_WAKEUP & c->bmAttributes)
> +		usb_gadget_set_remote_wakeup(gadget, 1);
> +	else
> +		usb_gadget_set_remote_wakeup(gadget, 0);
> +
>  	usb_gadget_vbus_draw(gadget, power);
>  	if (result >= 0 && cdev->delayed_status)
>  		result = USB_GADGET_DELAYED_STATUS;
> diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
> index b9f1136..4c639e9 100644
> --- a/drivers/usb/gadget/configfs.c
> +++ b/drivers/usb/gadget/configfs.c
> @@ -1761,6 +1761,9 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
>  		if (gadget_is_otg(gadget))
>  			c->descriptors = otg_desc;
>  
> +		/* Properly configure the bmAttributes wakeup bit */
> +		check_remote_wakeup_config(gadget, c);
> +
>  		cfg = container_of(c, struct config_usb_cfg, c);
>  		if (!list_empty(&cfg->string_list)) {
>  			i = 0;
> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> index 23b0629..3dcbba7 100644
> --- a/drivers/usb/gadget/udc/core.c
> +++ b/drivers/usb/gadget/udc/core.c
> @@ -514,6 +514,33 @@ int usb_gadget_wakeup(struct usb_gadget *gadget)
>  EXPORT_SYMBOL_GPL(usb_gadget_wakeup);
>  
>  /**
> + * usb_gadget_set_remote_wakeup - configures the device remote wakeup feature.
> + * @gadget:the device being configured for remote wakeup
> + * @set:value to be configured.
> + *
> + * set to one to enable remote wakeup feature and zero to disable it.
> + *
> + * returns zero on success, else negative errno.
> + */
> +int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
> +{
> +	int ret = 0;
> +
> +	if (!gadget->ops->set_remote_wakeup) {
> +		ret = -EOPNOTSUPP;
> +		goto out;
> +	}
> +
> +	ret = gadget->ops->set_remote_wakeup(gadget, set);
> +
> +out:
> +	trace_usb_gadget_set_remote_wakeup(gadget, ret);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_set_remote_wakeup);
> +
> +/**
>   * usb_gadget_set_selfpowered - sets the device selfpowered feature.
>   * @gadget:the device being declared as self-powered
>   *
> diff --git a/drivers/usb/gadget/udc/trace.h b/drivers/usb/gadget/udc/trace.h
> index abdbcb1..a5ed26f 100644
> --- a/drivers/usb/gadget/udc/trace.h
> +++ b/drivers/usb/gadget/udc/trace.h
> @@ -91,6 +91,11 @@ DEFINE_EVENT(udc_log_gadget, usb_gadget_wakeup,
>  	TP_ARGS(g, ret)
>  );
>  
> +DEFINE_EVENT(udc_log_gadget, usb_gadget_set_remote_wakeup,
> +	TP_PROTO(struct usb_gadget *g, int ret),
> +	TP_ARGS(g, ret)
> +);
> +
>  DEFINE_EVENT(udc_log_gadget, usb_gadget_set_selfpowered,
>  	TP_PROTO(struct usb_gadget *g, int ret),
>  	TP_ARGS(g, ret)
> diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
> index 608dc96..d949e91 100644
> --- a/include/linux/usb/composite.h
> +++ b/include/linux/usb/composite.h
> @@ -413,6 +413,8 @@ extern int composite_dev_prepare(struct usb_composite_driver *composite,
>  extern int composite_os_desc_req_prepare(struct usb_composite_dev *cdev,
>  					 struct usb_ep *ep0);
>  void composite_dev_cleanup(struct usb_composite_dev *cdev);
> +void check_remote_wakeup_config(struct usb_gadget *g,
> +				struct usb_configuration *c);
>  
>  static inline struct usb_composite_driver *to_cdriver(
>  		struct usb_gadget_driver *gdrv)
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 00750f7..1d79612 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -310,6 +310,7 @@ struct usb_udc;
>  struct usb_gadget_ops {
>  	int	(*get_frame)(struct usb_gadget *);
>  	int	(*wakeup)(struct usb_gadget *);
> +	int	(*set_remote_wakeup)(struct usb_gadget *, int set);
>  	int	(*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
>  	int	(*vbus_session) (struct usb_gadget *, int is_active);
>  	int	(*vbus_draw) (struct usb_gadget *, unsigned mA);
> @@ -384,6 +385,8 @@ struct usb_gadget_ops {
>   * @connected: True if gadget is connected.
>   * @lpm_capable: If the gadget max_speed is FULL or HIGH, this flag
>   *	indicates that it supports LPM as per the LPM ECN & errata.
> + * @wakeup_capable: True if gadget is capable of sending remote wakeup.
> + * @wakeup_armed: True if gadget is armed by the host for remote wakeup.
>   * @irq: the interrupt number for device controller.
>   * @id_number: a unique ID number for ensuring that gadget names are distinct
>   *
> @@ -445,6 +448,8 @@ struct usb_gadget {
>  	unsigned			deactivated:1;
>  	unsigned			connected:1;
>  	unsigned			lpm_capable:1;
> +	unsigned			wakeup_capable:1;
> +	unsigned			wakeup_armed:1;
>  	int				irq;
>  	int				id_number;
>  };
> @@ -601,6 +606,7 @@ static inline int gadget_is_otg(struct usb_gadget *g)
>  #if IS_ENABLED(CONFIG_USB_GADGET)
>  int usb_gadget_frame_number(struct usb_gadget *gadget);
>  int usb_gadget_wakeup(struct usb_gadget *gadget);
> +int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set);
>  int usb_gadget_set_selfpowered(struct usb_gadget *gadget);
>  int usb_gadget_clear_selfpowered(struct usb_gadget *gadget);
>  int usb_gadget_vbus_connect(struct usb_gadget *gadget);
> @@ -616,6 +622,8 @@ static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
>  { return 0; }
>  static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
>  { return 0; }
> +static inline int usb_gadget_set_remote_wakeup(struct usb_gadget *gadget, int set)
> +{ return 0; }
>  static inline int usb_gadget_set_selfpowered(struct usb_gadget *gadget)
>  { return 0; }
>  static inline int usb_gadget_clear_selfpowered(struct usb_gadget *gadget)
> -- 
> 2.7.4
> 

Reviewed-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

Thanks,
Thinh