1/*
2 * Filesystem based user-mode API to USB Gadget controller hardware
3 *
4 * Other than ep0 operations, most things are done by read() and write()
5 * on endpoint files found in one directory.  They are configured by
6 * writing descriptors, and then may be used for normal stream style
7 * i/o requests.  When ep0 is configured, the device can enumerate;
8 * when it's closed, the device disconnects from usb.  Operations on
9 * ep0 require ioctl() operations.
10 *
11 * Configuration and device descriptors get written to /dev/gadget/$CHIP,
12 * which may then be used to read usb_gadgetfs_event structs.  The driver
13 * may activate endpoints as it handles SET_CONFIGURATION setup events,
14 * or earlier; writing endpoint descriptors to /dev/gadget/$ENDPOINT
15 * then performing data transfers by reading or writing.
16 */
17
18#ifndef __LINUX_USB_GADGETFS_H
19#define __LINUX_USB_GADGETFS_H
20
21#include <linux/types.h>
22#include <linux/ioctl.h>
23
24#include <linux/usb/ch9.h>
25
26/*
27 * Events are delivered on the ep0 file descriptor, when the user mode driver
28 * reads from this file descriptor after writing the descriptors.  Don't
29 * stop polling this descriptor.
30 */
31
32enum usb_gadgetfs_event_type {
33	GADGETFS_NOP = 0,
34
35	GADGETFS_CONNECT,
36	GADGETFS_DISCONNECT,
37	GADGETFS_SETUP,
38	GADGETFS_SUSPEND,
39	/* and likely more ! */
40};
41
42/* NOTE:  this structure must stay the same size and layout on
43 * both 32-bit and 64-bit kernels.
44 */
45struct usb_gadgetfs_event {
46	union {
47		/* NOP, DISCONNECT, SUSPEND: nothing
48		 * ... some hardware can't report disconnection
49		 */
50
51		/* CONNECT: just the speed */
52		enum usb_device_speed	speed;
53
54		/* SETUP: packet; DATA phase i/o precedes next event
55		 *(setup.bmRequestType & USB_DIR_IN) flags direction
56		 * ... includes SET_CONFIGURATION, SET_INTERFACE
57		 */
58		struct usb_ctrlrequest	setup;
59	} u;
60	enum usb_gadgetfs_event_type	type;
61};
62
63
64/* The 'g' code is also used by printer gadget ioctl requests.
65 * Don't add any colliding codes to either driver, and keep
66 * them in unique ranges (size 0x20 for now).
67 */
68
69/* endpoint ioctls */
70
71/* IN transfers may be reported to the gadget driver as complete
72 *	when the fifo is loaded, before the host reads the data;
73 * OUT transfers may be reported to the host's "client" driver as
74 *	complete when they're sitting in the FIFO unread.
75 * THIS returns how many bytes are "unclaimed" in the endpoint fifo
76 * (needed for precise fault handling, when the hardware allows it)
77 */
78#define	GADGETFS_FIFO_STATUS	_IO('g', 1)
79
80/* discards any unclaimed data in the fifo. */
81#define	GADGETFS_FIFO_FLUSH	_IO('g', 2)
82
83/* resets endpoint halt+toggle; used to implement set_interface.
84 * some hardware (like pxa2xx) can't support this.
85 */
86#define	GADGETFS_CLEAR_HALT	_IO('g', 3)
87
88#endif /* __LINUX_USB_GADGETFS_H */
89