1 /*
2  * u_serial.h - interface to USB gadget "serial port"/TTY utilities
3  *
4  * Copyright (C) 2008 David Brownell
5  * Copyright (C) 2008 by Nokia Corporation
6  *
7  * This software is distributed under the terms of the GNU General
8  * Public License ("GPL") as published by the Free Software Foundation,
9  * either version 2 of that License or (at your option) any later version.
10  */
11 
12 #ifndef __U_SERIAL_H
13 #define __U_SERIAL_H
14 
15 #include <linux/usb/composite.h>
16 #include <linux/usb/cdc.h>
17 
18 #define MAX_U_SERIAL_PORTS	4
19 
20 struct f_serial_opts {
21 	struct usb_function_instance func_inst;
22 	u8 port_num;
23 };
24 
25 /*
26  * One non-multiplexed "serial" I/O port ... there can be several of these
27  * on any given USB peripheral device, if it provides enough endpoints.
28  *
29  * The "u_serial" utility component exists to do one thing:  manage TTY
30  * style I/O using the USB peripheral endpoints listed here, including
31  * hookups to sysfs and /dev for each logical "tty" device.
32  *
33  * REVISIT at least ACM could support tiocmget() if needed.
34  *
35  * REVISIT someday, allow multiplexing several TTYs over these endpoints.
36  */
37 struct gserial {
38 	struct usb_function		func;
39 
40 	/* port is managed by gserial_{connect,disconnect} */
41 	struct gs_port			*ioport;
42 
43 	struct usb_ep			*in;
44 	struct usb_ep			*out;
45 
46 	/* REVISIT avoid this CDC-ACM support harder ... */
47 	struct usb_cdc_line_coding port_line_coding;	/* 9600-8-N-1 etc */
48 
49 	/* notification callbacks */
50 	void (*connect)(struct gserial *p);
51 	void (*disconnect)(struct gserial *p);
52 	int (*send_break)(struct gserial *p, int duration);
53 };
54 
55 /* utilities to allocate/free request and buffer */
56 struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags);
57 void gs_free_req(struct usb_ep *, struct usb_request *req);
58 
59 /* management of individual TTY ports */
60 int gserial_alloc_line(unsigned char *port_line);
61 void gserial_free_line(unsigned char port_line);
62 
63 /* connect/disconnect is handled by individual functions */
64 int gserial_connect(struct gserial *, u8 port_num);
65 void gserial_disconnect(struct gserial *);
66 
67 /* functions are bound to configurations by a config or gadget driver */
68 int gser_bind_config(struct usb_configuration *c, u8 port_num);
69 int obex_bind_config(struct usb_configuration *c, u8 port_num);
70 
71 #endif /* __U_SERIAL_H */
72