usb_alloc_urb(9) [centos man page]

USB_ALLOC_URB(9)						   USB Core APIs						  USB_ALLOC_URB(9)

NAME

       usb_alloc_urb - creates a new urb for a USB driver to use

SYNOPSIS

       struct urb * usb_alloc_urb(int iso_packets, gfp_t mem_flags);

ARGUMENTS

       iso_packets
	   number of iso packets for this urb

       mem_flags
	   the type of memory to allocate, see kmalloc for a list of valid options for this.

DESCRIPTION

       Creates an urb for the USB driver to use, initializes a few internal structures, incrementes the usage counter, and returns a pointer to
       it.

       If the driver want to use this urb for interrupt, control, or bulk endpoints, pass '0' as the number of iso packets.

       The driver must call usb_free_urb when it is finished with the urb.

RETURN

       A pointer to the new urb, or NULL if no memory is available.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014							  USB_ALLOC_URB(9)

USB_FILL_INT_URB(9)					  Host-Side Data Types and Macro				       USB_FILL_INT_URB(9)

NAME

       usb_fill_int_urb - macro to help initialize a interrupt urb

SYNOPSIS

       void usb_fill_int_urb(struct urb * urb, struct usb_device * dev, unsigned int pipe, void * transfer_buffer, int buffer_length,
			     usb_complete_t complete_fn, void * context, int interval);

ARGUMENTS

       urb
	   pointer to the urb to initialize.

       dev
	   pointer to the struct usb_device for this urb.

       pipe
	   the endpoint pipe

       transfer_buffer
	   pointer to the transfer buffer

       buffer_length
	   length of the transfer buffer

       complete_fn
	   pointer to the usb_complete_t function

       context
	   what to set the urb context to.

       interval
	   what to set the urb interval to, encoded like the endpoint descriptor's bInterval value.

DESCRIPTION

       Initializes a interrupt urb with the proper information needed to submit it to a device.

       Note that High Speed and SuperSpeed interrupt endpoints use a logarithmic encoding of the endpoint interval, and express polling intervals
       in microframes (eight per millisecond) rather than in frames (one per millisecond).

       Wireless USB also uses the logarithmic encoding, but specifies it in units of 128us instead of 125us. For Wireless USB devices, the
       interval is passed through to the host controller, rather than being translated into microframe units.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						       USB_FILL_INT_URB(9)