1 #ifndef __LINUX_USB_GADGETFS_H
2 #define __LINUX_USB_GADGETFS_H
7 #include <linux/usb/ch9.h>
10 * Filesystem based user-mode API to USB Gadget controller hardware
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.
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.
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.
32 enum usb_gadgetfs_event_type {
42 /* NOTE: this structure must stay the same size and layout on
43 * both 32-bit and 64-bit kernels.
45 struct usb_gadgetfs_event {
47 // NOP, DISCONNECT, SUSPEND: nothing
48 // ... some hardware can't report disconnection
50 // CONNECT: just the speed
51 enum usb_device_speed speed;
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;
58 enum usb_gadgetfs_event_type type;
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)
71 #define GADGETFS_FIFO_STATUS _IO('g',1)
73 /* discards any unclaimed data in the fifo. */
74 #define GADGETFS_FIFO_FLUSH _IO('g',2)
76 /* resets endpoint halt+toggle; used to implement set_interface.
77 * some hardware (like pxa2xx) can't support this.
79 #define GADGETFS_CLEAR_HALT _IO('g',3)
81 #endif /* __LINUX_USB_GADGETFS_H */