1/* SPDX-License-Identifier: GPL-2.0+ */
 2/*
 3 * u_serial.h - interface to USB gadget "serial port"/TTY utilities
 4 *
 5 * Copyright (C) 2008 David Brownell
 6 * Copyright (C) 2008 by Nokia Corporation
 7 */
 8
 9#ifndef __U_SERIAL_H
10#define __U_SERIAL_H
11
12#include <linux/usb/composite.h>
13#include <linux/usb/cdc.h>
14
15#define MAX_U_SERIAL_PORTS	8
16
17struct f_serial_opts {
18	struct usb_function_instance func_inst;
19	u8 port_num;
20};
21
22/*
23 * One non-multiplexed "serial" I/O port ... there can be several of these
24 * on any given USB peripheral device, if it provides enough endpoints.
25 *
26 * The "u_serial" utility component exists to do one thing:  manage TTY
27 * style I/O using the USB peripheral endpoints listed here, including
28 * hookups to sysfs and /dev for each logical "tty" device.
29 *
30 * REVISIT at least ACM could support tiocmget() if needed.
31 *
32 * REVISIT someday, allow multiplexing several TTYs over these endpoints.
33 */
34struct gserial {
35	struct usb_function		func;
36
37	/* port is managed by gserial_{connect,disconnect} */
38	struct gs_port			*ioport;
39
40	struct usb_ep			*in;
41	struct usb_ep			*out;
42
43	/* REVISIT avoid this CDC-ACM support harder ... */
44	struct usb_cdc_line_coding port_line_coding;	/* 9600-8-N-1 etc */
45
46	/* notification callbacks */
47	void (*connect)(struct gserial *p);
48	void (*disconnect)(struct gserial *p);
49	int (*send_break)(struct gserial *p, int duration);
50};
51
52/* utilities to allocate/free request and buffer */
53struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags);
54void gs_free_req(struct usb_ep *, struct usb_request *req);
55
56/* management of individual TTY ports */
57int gserial_alloc_line_no_console(unsigned char *port_line);
58int gserial_alloc_line(unsigned char *port_line);
59void gserial_free_line(unsigned char port_line);
60
61#ifdef CONFIG_U_SERIAL_CONSOLE
62
63ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t count);
64ssize_t gserial_get_console(unsigned char port_num, char *page);
65
66#endif /* CONFIG_U_SERIAL_CONSOLE */
67
68/* connect/disconnect is handled by individual functions */
69int gserial_connect(struct gserial *, u8 port_num);
70void gserial_disconnect(struct gserial *);
71void gserial_suspend(struct gserial *p);
72void gserial_resume(struct gserial *p);
73
74#endif /* __U_SERIAL_H */