aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/usb/gadgetfs.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/usb/gadgetfs.h')
-rw-r--r--include/linux/usb/gadgetfs.h81
1 files changed, 81 insertions, 0 deletions
diff --git a/include/linux/usb/gadgetfs.h b/include/linux/usb/gadgetfs.h
new file mode 100644
index 000000000000..e8654c338729
--- /dev/null
+++ b/include/linux/usb/gadgetfs.h
@@ -0,0 +1,81 @@
1#ifndef __LINUX_USB_GADGETFS_H
2#define __LINUX_USB_GADGETFS_H
3
4#include <asm/types.h>
5#include <asm/ioctl.h>
6
7#include <linux/usb/ch9.h>
8
9/*
10 * Filesystem based user-mode API to USB Gadget controller hardware
11 *
12 * Other than ep0 operations, most things are done by read() and write()
13 * on endpoint files found in one directory. They are configured by
14 * writing descriptors, and then may be used for normal stream style
15 * i/o requests. When ep0 is configured, the device can enumerate;
16 * when it's closed, the device disconnects from usb. Operations on
17 * ep0 require ioctl() operations.
18 *
19 * Configuration and device descriptors get written to /dev/gadget/$CHIP,
20 * which may then be used to read usb_gadgetfs_event structs. The driver
21 * may activate endpoints as it handles SET_CONFIGURATION setup events,
22 * or earlier; writing endpoint descriptors to /dev/gadget/$ENDPOINT
23 * then performing data transfers by reading or writing.
24 */
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 // CONNECT: just the speed
51 enum usb_device_speed speed;
52
53 // SETUP: packet; DATA phase i/o precedes next event
54 // (setup.bmRequestType & USB_DIR_IN) flags direction
55 // ... includes SET_CONFIGURATION, SET_INTERFACE
56 struct usb_ctrlrequest setup;
57 } u;
58 enum usb_gadgetfs_event_type type;
59};
60
61
62/* endpoint ioctls */
63
64/* IN transfers may be reported to the gadget driver as complete
65 * when the fifo is loaded, before the host reads the data;
66 * OUT transfers may be reported to the host's "client" driver as
67 * complete when they're sitting in the FIFO unread.
68 * THIS returns how many bytes are "unclaimed" in the endpoint fifo
69 * (needed for precise fault handling, when the hardware allows it)
70 */
71#define GADGETFS_FIFO_STATUS _IO('g',1)
72
73/* discards any unclaimed data in the fifo. */
74#define GADGETFS_FIFO_FLUSH _IO('g',2)
75
76/* resets endpoint halt+toggle; used to implement set_interface.
77 * some hardware (like pxa2xx) can't support this.
78 */
79#define GADGETFS_CLEAR_HALT _IO('g',3)
80
81#endif /* __LINUX_USB_GADGETFS_H */