LXR linux/drivers/usb/gadget/function/u

   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/* functions are bound to configurations by a config or gadget driver */
  75int gser_bind_config(struct usb_configuration *c, u8 port_num);
  76int obex_bind_config(struct usb_configuration *c, u8 port_num);
  77
  78#endif /* __U_SERIAL_H */
  79