/* SPDX-License-Identifier: GPL-2.0+ *//* * u_serial.h - interface to USB gadget "serial port"/TTY utilities * * Copyright (C) 2008 David Brownell * Copyright (C) 2008 by Nokia Corporation */ #ifndef __U_SERIAL_H#define __U_SERIAL_H #include <linux/usb/composite.h>#include <linux/usb/cdc.h> #define MAX_U_SERIAL_PORTS	8 struct f_serial_opts {	struct usb_function_instance func_inst;	u8 port_num;	u8 protocol; 	struct mutex lock; /* protect instances */	int instances;}; /* * One non-multiplexed "serial" I/O port ... there can be several of these * on any given USB peripheral device, if it provides enough endpoints. * * The "u_serial" utility component exists to do one thing:  manage TTY * style I/O using the USB peripheral endpoints listed here, including * hookups to sysfs and /dev for each logical "tty" device. * * REVISIT at least ACM could support tiocmget() if needed. * * REVISIT someday, allow multiplexing several TTYs over these endpoints. */struct gserial {	struct usb_function		func; 	/* port is managed by gserial_{connect,disconnect} */	struct gs_port			*ioport; 	struct usb_ep			*in;	struct usb_ep			*out; 	/* REVISIT avoid this CDC-ACM support harder ... */	struct usb_cdc_line_coding port_line_coding;	/* 9600-8-N-1 etc */ 	/* notification callbacks */	void (*connect)(struct gserial *p);	void (*disconnect)(struct gserial *p);	int (*send_break)(struct gserial *p, int duration);}; /* utilities to allocate/free request and buffer */struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags);void gs_free_req(struct usb_ep *, struct usb_request *req); /* management of individual TTY ports */int gserial_alloc_line_no_console(unsigned char *port_line);int gserial_alloc_line(unsigned char *port_line);void gserial_free_line(unsigned char port_line); #ifdef CONFIG_U_SERIAL_CONSOLE ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t count);ssize_t gserial_get_console(unsigned char port_num, char *page); #endif /* CONFIG_U_SERIAL_CONSOLE */ /* connect/disconnect is handled by individual functions */int gserial_connect(struct gserial *, u8 port_num);void gserial_disconnect(struct gserial *);void gserial_suspend(struct gserial *p);void gserial_resume(struct gserial *p); #endif /* __U_SERIAL_H */