On Mon, Feb 06, 2023, Elson Roy Serrao wrote:
> A function which is in function suspend state has to send a
> function wake notification to the host in case it needs to
> exit from this state and resume data transfer. Add support to
> handle such requests by exposing a new gadget op.
>
> Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
> ---
> drivers/usb/gadget/composite.c | 26 ++++++++++++++++++++++++++
> drivers/usb/gadget/udc/core.c | 19 +++++++++++++++++++
> include/linux/usb/composite.h | 6 ++++++
> include/linux/usb/gadget.h | 4 ++++
> 4 files changed, 55 insertions(+)
>
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index e459fb0..aa243d8 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -492,6 +492,32 @@ int usb_interface_id(struct usb_configuration *config,
> }
> EXPORT_SYMBOL_GPL(usb_interface_id);
>
> +int usb_func_wakeup(struct usb_function *func)
> +{
> + int ret, id;
> +
> + if (!func->func_rw_armed) {
> + ERROR(func->config->cdev, "func remote wakeup not enabled\n");
> + return -EINVAL;
> + }
> +
> + DBG(func->config->cdev, "%s function wakeup\n", func->name);
Do we need this DBG print?
> +
> + for (id = 0; id < MAX_CONFIG_INTERFACES; id++)
> + if (func->config->interface[id] == func)
> + break;
> +
> + if (id == MAX_CONFIG_INTERFACES) {
> + ERROR(func->config->cdev, "Invalid function id:%d\n", id);
> + return -EINVAL;
> + }
> +
> + ret = usb_gadget_func_wakeup(func->config->cdev->gadget, id);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(usb_func_wakeup);
> +
> static u8 encode_bMaxPower(enum usb_device_speed speed,
> struct usb_configuration *c)
> {
> diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c
> index 5874d4f..63b5944 100644
> --- a/drivers/usb/gadget/udc/core.c
> +++ b/drivers/usb/gadget/udc/core.c
> @@ -846,6 +846,25 @@ int usb_gadget_activate(struct usb_gadget *gadget)
> }
> EXPORT_SYMBOL_GPL(usb_gadget_activate);
>
> +/**
> + * usb_gadget_func_wakeup - sends function wake notification to the host.
> + * If the link is in low power state, first brings the link to active state.
> + * @gadget: controller used to wake up the host
> + * @interface_id: interface on which function wake notification is sent.
> + *
> + * Returns zero on success, else negative error code if the hardware
On completion, the device notification is sent? So it's a synchonous
call right? Probably can't be called in interrupt context? Can you
document the expectation here.
Thanks,
Thinh
> + * doesn't support such attempts. Drivers must return device descriptors that
> + * report their ability to support this, or hosts won't enable it.
> + */
> +int usb_gadget_func_wakeup(struct usb_gadget *gadget, int intf_id)
> +{
> + if (!gadget->ops->func_wakeup)
> + return -EOPNOTSUPP;
> +
> + return gadget->ops->func_wakeup(gadget, intf_id);
> +}
> +EXPORT_SYMBOL_GPL(usb_gadget_func_wakeup);
> +
> /* ------------------------------------------------------------------------- */
>
> #ifdef CONFIG_HAS_DMA
> diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
> index 91d22c3..c9573ba 100644
> --- a/include/linux/usb/composite.h
> +++ b/include/linux/usb/composite.h
> @@ -150,6 +150,9 @@ struct usb_os_desc_table {
> * GetStatus() request when the recipient is Interface.
> * @func_suspend: callback to be called when
> * SetFeature(FUNCTION_SUSPEND) is reseived
> + * @func_suspended: Indicates whether the function is in function suspend state.
> + * @func_rw_armed: Indicates whether the function is armed by the host for
> + * wakeup signaling.
> *
> * A single USB function uses one or more interfaces, and should in most
> * cases support operation at both full and high speeds. Each function is
> @@ -220,6 +223,8 @@ struct usb_function {
> int (*get_status)(struct usb_function *);
> int (*func_suspend)(struct usb_function *,
> u8 suspend_opt);
> + bool func_suspended;
> + bool func_rw_armed;
> /* private: */
> /* internals */
> struct list_head list;
> @@ -241,6 +246,7 @@ int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,
>
> int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
> struct usb_ep *_ep);
> +int usb_func_wakeup(struct usb_function *func);
>
> #define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */
>
> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> index 05d1449..1e73943 100644
> --- a/include/linux/usb/gadget.h
> +++ b/include/linux/usb/gadget.h
> @@ -309,6 +309,7 @@ struct usb_udc;
> struct usb_gadget_ops {
> int (*get_frame)(struct usb_gadget *);
> int (*wakeup)(struct usb_gadget *);
> + int (*func_wakeup)(struct usb_gadget *gadget, int intf_id);
> int (*set_remotewakeup)(struct usb_gadget *, int set);
> int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
> int (*vbus_session) (struct usb_gadget *, int is_active);
> @@ -616,6 +617,7 @@ int usb_gadget_disconnect(struct usb_gadget *gadget);
> int usb_gadget_deactivate(struct usb_gadget *gadget);
> int usb_gadget_activate(struct usb_gadget *gadget);
> int usb_gadget_check_config(struct usb_gadget *gadget);
> +int usb_gadget_func_wakeup(struct usb_gadget *gadget, int intf_id);
> #else
> static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
> { return 0; }
> @@ -643,6 +645,8 @@ static inline int usb_gadget_activate(struct usb_gadget *gadget)
> { return 0; }
> static inline int usb_gadget_check_config(struct usb_gadget *gadget)
> { return 0; }
> +static inline int usb_gadget_func_wakeup(struct usb_gadget *gadget, int intf_id)
> +{ return 0; }
> #endif /* CONFIG_USB_GADGET */
>
> /*-------------------------------------------------------------------------*/
> --
> 2.7.4
>
