[linux.git] / include / linux / usb_gadgetfs.h


#include <asm/types.h>
#include <asm/ioctl.h>

#include <linux/usb/ch9.h>

/*
 * Filesystem based user-mode API to USB Gadget controller hardware
 *
 * Almost everything can be done with only read and write operations,
 * 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.
 *
 * 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.
 */

/*
 * Events are delivered on the ep0 file descriptor, if the user mode driver
 * reads from this file descriptor after writing the descriptors.  Don't
 * stop polling this descriptor, if you write that kind of driver.
 */

enum usb_gadgetfs_event_type {
	GADGETFS_NOP = 0,

	GADGETFS_CONNECT,
	GADGETFS_DISCONNECT,
	GADGETFS_SETUP,
	GADGETFS_SUSPEND,
	// and likely more !
};

struct usb_gadgetfs_event {
	enum usb_gadgetfs_event_type	type;
	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;
};


/* 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)
Commit	Line	Data
1da177e4 LT	1
	2	#include <asm/types.h>
	3	#include <asm/ioctl.h>
	4
5f848137	5	#include <linux/usb/ch9.h>
1da177e4 LT	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
	29	enum 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
	39	struct 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