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	u8 protocol;
21
22	struct mutex lock; /* protect instances */
23	int instances;
24};
25
26/*
27 * One non-multiplexed "serial" I/O port ... there can be several of these
28 * on any given USB peripheral device, if it provides enough endpoints.
29 *
30 * The "u_serial" utility component exists to do one thing:  manage TTY
31 * style I/O using the USB peripheral endpoints listed here, including
32 * hookups to sysfs and /dev for each logical "tty" device.
33 *
34 * REVISIT at least ACM could support tiocmget() if needed.
35 *
36 * REVISIT someday, allow multiplexing several TTYs over these endpoints.
37 */
38struct gserial {
39	struct usb_function		func;
40
41	/* port is managed by gserial_{connect,disconnect} */
42	struct gs_port			*ioport;
43
44	struct usb_ep			*in;
45	struct usb_ep			*out;
46
47	/* REVISIT avoid this CDC-ACM support harder ... */
48	struct usb_cdc_line_coding port_line_coding;	/* 9600-8-N-1 etc */
49
50	/* notification callbacks */
51	void (*connect)(struct gserial *p);
52	void (*disconnect)(struct gserial *p);
53	int (*send_break)(struct gserial *p, int duration);
54};
55
56/* utilities to allocate/free request and buffer */
57struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags);
58void gs_free_req(struct usb_ep *, struct usb_request *req);
59
60/* management of individual TTY ports */
61int gserial_alloc_line_no_console(unsigned char *port_line);
62int gserial_alloc_line(unsigned char *port_line);
63void gserial_free_line(unsigned char port_line);
64
65#ifdef CONFIG_U_SERIAL_CONSOLE
66
67ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t count);
68ssize_t gserial_get_console(unsigned char port_num, char *page);
69
70#endif /* CONFIG_U_SERIAL_CONSOLE */
71
72/* connect/disconnect is handled by individual functions */
73int gserial_connect(struct gserial *, u8 port_num);
74void gserial_disconnect(struct gserial *);
75void gserial_suspend(struct gserial *p);
76void gserial_resume(struct gserial *p);
77
78#endif /* __U_SERIAL_H */