/*
* Filesystem based user-mode API to USB Gadget controller hardware
*
* Other than ep0 operations, most things are done by read() and write()
* 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. Operations on
* ep0 require ioctl() operations.
*
* 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.
*/

#ifndef __LINUX_USB_GADGETFS_H
#define __LINUX_USB_GADGETFS_H

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

#include <linux/usb/ch9.h>

/*
* Events are delivered on the ep0 file descriptor, when the user mode driver
* reads from this file descriptor after writing the descriptors. Don't
* stop polling this descriptor.
*/

enum usb_gadgetfs_event_type {
GADGETFS_NOP = 0,

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

/* NOTE: this structure must stay the same size and layout on
* both 32-bit and 64-bit kernels.
*/
struct usb_gadgetfs_event {
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;
enum usb_gadgetfs_event_type type;
};


/* The 'g' code is also used by printer gadget ioctl requests.
* Don't add any colliding codes to either driver, and keep
* them in unique ranges (size 0x20 for now).
*/

/* 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)

#endif /* __LINUX_USB_GADGETFS_H */