• Tony Olech's avatar
    USB: u132-hcd: host controller driver for ELAN U132 adapter · d774efea
    Tony Olech authored
    This "u132-hcd" module is one half of the "driver" for
    ELAN's U132 which is a USB to CardBus OHCI controller
    adapter. This module needs the "ftdi-elan" module in
    order to communicate to CardBus OHCI controller inserted
    into the U132 adapter.
    
    When the "ftdi-elan" module detects a supported CardBus
    OHCI controller in the U132 adapter it loads this "u132-hcd"
    module.
    
    Upon a successful device probe() the single workqueue
    is started up which does all the processing of commands
    from the USB core that implement the host controller.
    
    The workqueue maintains the urb queues and issues commands
    via the functions exported by the "ftdi-elan" module. Each
    such command will result in a callback.
    
    Note that the "ftdi-elan" module is a USB client driver.
    
    Note that this "u132-hcd" module is a (cut-down OHCI)
    host controller.
    
    Thus we have a topology with the parent of a host controller
    being a USB client! This really stresses the USB subsystem
    semaphore/mutex handling in the module removal.
    Signed-off-by: default avatarTony Olech <tony.olech@elandigitalsystems.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    d774efea
u132-hcd.c 133 KB