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 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 */ 38 struct 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 */ 57 struct usb_request *gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t flags); 58 void gs_free_req(struct usb_ep *, struct usb_request *req); 59 60 /* management of individual TTY ports */ 61 int gserial_alloc_line_no_console(unsigned char *port_line); 62 int gserial_alloc_line(unsigned char *port_line); 63 void gserial_free_line(unsigned char port_line); 64 65 #ifdef CONFIG_U_SERIAL_CONSOLE 66 67 ssize_t gserial_set_console(unsigned char port_num, const char *page, size_t count); 68 ssize_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 */ 73 int gserial_connect(struct gserial *, u8 port_num); 74 void gserial_disconnect(struct gserial *); 75 void gserial_suspend(struct gserial *p); 76 void gserial_resume(struct gserial *p); 77 78 #endif /* __U_SERIAL_H */ 79