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 17 struct 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 */ 34 struct 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 */ 53 struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags); 54 void gs_free_req(struct usb_ep *, struct usb_request *req); 55 56 /* management of individual TTY ports */ 57 int gserial_alloc_line_no_console(unsigned char *port_line); 58 int gserial_alloc_line(unsigned char *port_line); 59 void gserial_free_line(unsigned char port_line); 60 61 #ifdef CONFIG_U_SERIAL_CONSOLE 62 63 ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t count); 64 ssize_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 */ 69 int gserial_connect(struct gserial *, u8 port_num); 70 void gserial_disconnect(struct gserial *); 71 void gserial_suspend(struct gserial *p); 72 void gserial_resume(struct gserial *p); 73 74 #endif /* __U_SERIAL_H */ 75