90 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			90 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 | 
						|
/*
 | 
						|
 * 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 */
 |