usb_string_ids_n(9) [centos man page]

USB_STRING_IDS_N(9)					      Kernel Mode Gadget API					       USB_STRING_IDS_N(9)

NAME

       usb_string_ids_n - allocate unused string IDs in batch

SYNOPSIS

       int usb_string_ids_n(struct usb_composite_dev * c, unsigned n);

ARGUMENTS

       c
	   the device whose string descriptor IDs are being allocated

       n
	   number of string IDs to allocate

CONTEXT

       single threaded during gadget setup

DESCRIPTION

       Returns the first requested ID. This ID and next n-1 IDs are now valid IDs. At least provided that n is non-zero because if it is, returns
       last requested ID which is now very useful information.

       usb_string_ids_n() is called from bind callbacks to allocate string IDs. Drivers for functions, configurations, or gadgets will then store
       that ID in the appropriate descriptors and string table.

       All string identifier should be allocated using this, usb_string_id() or usb_string_ids_n() routine, to ensure that for example different
       functions don't wrongly assign different meanings to the same identifier.

AUTHOR

       David Brownell <dbrownell@users.sourceforge.net>
	   Author.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						       USB_STRING_IDS_N(9)

STRUCT 
USB_COMPOSITE(9) 				      Kernel Mode Gadget API					   STRUCT USB_COMPOSITE(9)

NAME

       struct_usb_composite_driver - groups configurations into a gadget

SYNOPSIS

       struct usb_composite_driver {
	 const char * name;
	 const struct usb_device_descriptor * dev;
	 struct usb_gadget_strings ** strings;
	 enum usb_device_speed max_speed;
	 unsigned needs_serial:1;
	 int (* bind) (struct usb_composite_dev *cdev);
	 int (* unbind) (struct usb_composite_dev *);
	 void (* disconnect) (struct usb_composite_dev *);
	 void (* suspend) (struct usb_composite_dev *);
	 void (* resume) (struct usb_composite_dev *);
	 struct usb_gadget_driver gadget_driver;
       };

MEMBERS

       name
	   For diagnostics, identifies the driver.

       dev
	   Template descriptor for the device, including default device identifiers.

       strings
	   tables of strings, keyed by identifiers assigned during bind and language IDs provided in control requests. Note: The first entries are
	   predefined. The first entry that may be used is USB_GADGET_FIRST_AVAIL_IDX

       max_speed
	   Highest speed the driver supports.

       needs_serial
	   set to 1 if the gadget needs userspace to provide a serial number. If one is not provided, warning will be printed.

       bind
	   (REQUIRED) Used to allocate resources that are shared across the whole device, such as string IDs, and add its configurations using
	   usb_add_config(). This may fail by returning a negative errno value; it should return zero on successful initialization.

       unbind
	   Reverses bind; called as a side effect of unregistering this driver.

       disconnect
	   optional driver disconnect method

       suspend
	   Notifies when the host stops sending USB traffic, after function notifications

       resume
	   Notifies configuration when the host restarts USB traffic, before function notifications

       gadget_driver
	   Gadget driver controlling this driver

DESCRIPTION

       Devices default to reporting self powered operation. Devices which rely on bus powered operation should report this in their bind method.

       Before returning from bind, various fields in the template descriptor may be overridden. These include the idVendor/idProduct/bcdDevice
       values normally to bind the appropriate host side driver, and the three strings (iManufacturer, iProduct, iSerialNumber) normally used to
       provide user meaningful device identifiers. (The strings will not be defined unless they are defined in dev and strings.) The correct ep0
       maxpacket size is also reported, as defined by the underlying controller driver.

AUTHOR

       David Brownell <dbrownell@users.sourceforge.net>
	   Author.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   STRUCT USB_COMPOSITE(9)