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