source: svn/trunk/newcon3bcm2_21bu/toolchain/mips-linux-uclibc/include/linux/usb_gadgetfs.h

#include <asm/types.h>
#include <asm/ioctl.h>

#include <linux/usb_ch9.h>

/*
 * Filesystem based user-mode API to USB Gadget controller hardware
 *
 * Almost everything can be done with only read and write operations,
 * on endpoint files found in one directory.  They are configured by
 * writing descriptors, and then may be used for normal stream style
 * i/o requests.  When ep0 is configured, the device can enumerate;
 * when it's closed, the device disconnects from usb.
 *
 * Configuration and device descriptors get written to /dev/gadget/$CHIP,
 * which may then be used to read usb_gadgetfs_event structs.  The driver
 * may activate endpoints as it handles SET_CONFIGURATION setup events,
 * or earlier; writing endpoint descriptors to /dev/gadget/$ENDPOINT
 * then performing data transfers by reading or writing.
 */

/*
 * Events are delivered on the ep0 file descriptor, if the user mode driver
 * reads from this file descriptor after writing the descriptors.  Don't
 * stop polling this descriptor, if you write that kind of driver.
 */

enum usb_gadgetfs_event_type {
        GADGETFS_NOP = 0,

        GADGETFS_CONNECT,
        GADGETFS_DISCONNECT,
        GADGETFS_SETUP,
        GADGETFS_SUSPEND,
        // and likely more !
};

struct usb_gadgetfs_event {
        enum usb_gadgetfs_event_type    type;
        union {
                // NOP, DISCONNECT, SUSPEND: nothing
                // ... some hardware can't report disconnection

                // CONNECT: just the speed
                enum usb_device_speed   speed;

                // SETUP: packet; DATA phase i/o precedes next event
                // (setup.bmRequestType & USB_DIR_IN) flags direction 
                // ... includes SET_CONFIGURATION, SET_INTERFACE
                struct usb_ctrlrequest  setup;
        } u;
};


/* endpoint ioctls */

/* IN transfers may be reported to the gadget driver as complete
 *      when the fifo is loaded, before the host reads the data;
 * OUT transfers may be reported to the host's "client" driver as
 *      complete when they're sitting in the FIFO unread.
 * THIS returns how many bytes are "unclaimed" in the endpoint fifo
 * (needed for precise fault handling, when the hardware allows it)
 */
#define GADGETFS_FIFO_STATUS    _IO('g',1)

/* discards any unclaimed data in the fifo. */
#define GADGETFS_FIFO_FLUSH     _IO('g',2)

/* resets endpoint halt+toggle; used to implement set_interface.
 * some hardware (like pxa2xx) can't support this.
 */
#define GADGETFS_CLEAR_HALT     _IO('g',3)