include/linux/usb/serial.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB Serial Converter stuff
   4  *
   5  *      Copyright (C) 1999 - 2012
   6  *          Greg Kroah-Hartman (greg@kroah.com)
   7  *
   8  *      This program is free software; you can redistribute it and/or modify
   9  *      it under the terms of the GNU General Public License as published by
  10  *      the Free Software Foundation; version 2 of the License.
  11  *
  12  */
  13
  14 #ifndef __LINUX_USB_SERIAL_H
  15 #define __LINUX_USB_SERIAL_H
  16
  17 #include <linux/kref.h>
  18 #include <linux/mutex.h>
  19 #include <linux/serial.h>
  20 #include <linux/sysrq.h>
  21 #include <linux/kfifo.h>
  22
  23 /* The maximum number of ports one device can grab at once */
  24 #define MAX_NUM_PORTS           16
  25
  26 /* parity check flag */
  27 #define RELEVANT_IFLAG(iflag)   (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
  28
  29 /* USB serial flags */
  30 #define USB_SERIAL_WRITE_BUSY   0
  31
  32 /**
  33  * usb_serial_port: structure for the specific ports of a device.
  34  * @serial: pointer back to the struct usb_serial owner of this port.
  35  * @port: pointer to the corresponding tty_port for this port.
  36  * @lock: spinlock to grab when updating portions of this structure.
  37  * @minor: the minor number of the port
  38  * @port_number: the struct usb_serial port number of this port (starts at 0)
  39  * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
  40  * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
  41  * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
  42  *      for this port.
  43  * @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
  44  * @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
  45  * @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
  46  * @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
  47  *      for this port.
  48  * @bulk_in_buffer: pointer to the bulk in buffer for this port.
  49  * @bulk_in_size: the size of the bulk_in_buffer, in bytes.
  50  * @read_urb: pointer to the bulk in struct urb for this port.
  51  * @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
  52  *      port.
  53  * @bulk_in_buffers: pointers to the bulk in buffers for this port
  54  * @read_urbs: pointers to the bulk in urbs for this port
  55  * @read_urbs_free: status bitmap the for bulk in urbs
  56  * @bulk_out_buffer: pointer to the bulk out buffer for this port.
  57  * @bulk_out_size: the size of the bulk_out_buffer, in bytes.
  58  * @write_urb: pointer to the bulk out struct urb for this port.
  59  * @write_fifo: kfifo used to buffer outgoing data
  60  * @bulk_out_buffers: pointers to the bulk out buffers for this port
  61  * @write_urbs: pointers to the bulk out urbs for this port
  62  * @write_urbs_free: status bitmap the for bulk out urbs
  63  * @icount: interrupt counters
  64  * @tx_bytes: number of bytes currently in host stack queues
  65  * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
  66  *      port.
  67  * @flags: usb serial port flags
  68  * @write_wait: a wait_queue_head_t used by the port.
  69  * @work: work queue entry for the line discipline waking up.
  70  * @throttled: nonzero if the read urb is inactive to throttle the device
  71  * @throttle_req: nonzero if the tty wants to throttle us
  72  * @dev: pointer to the serial device
  73  *
  74  * This structure is used by the usb-serial core and drivers for the specific
  75  * ports of a device.
  76  */
  77 struct usb_serial_port {
  78         struct usb_serial       *serial;
  79         struct tty_port         port;
  80         spinlock_t              lock;
  81         u32                     minor;
  82         u8                      port_number;
  83
  84         unsigned char           *interrupt_in_buffer;
  85         struct urb              *interrupt_in_urb;
  86         __u8                    interrupt_in_endpointAddress;
  87
  88         unsigned char           *interrupt_out_buffer;
  89         int                     interrupt_out_size;
  90         struct urb              *interrupt_out_urb;
  91         __u8                    interrupt_out_endpointAddress;
  92
  93         unsigned char           *bulk_in_buffer;
  94         int                     bulk_in_size;
  95         struct urb              *read_urb;
  96         __u8                    bulk_in_endpointAddress;
  97
  98         unsigned char           *bulk_in_buffers[2];
  99         struct urb              *read_urbs[2];
 100         unsigned long           read_urbs_free;
 101
 102         unsigned char           *bulk_out_buffer;
 103         int                     bulk_out_size;
 104         struct urb              *write_urb;
 105         struct kfifo            write_fifo;
 106
 107         unsigned char           *bulk_out_buffers[2];
 108         struct urb              *write_urbs[2];
 109         unsigned long           write_urbs_free;
 110         __u8                    bulk_out_endpointAddress;
 111
 112         struct async_icount     icount;
 113         int                     tx_bytes;
 114
 115         unsigned long           flags;
 116         wait_queue_head_t       write_wait;
 117         struct work_struct      work;
 118         char                    throttled;
 119         char                    throttle_req;
 120         unsigned long           sysrq; /* sysrq timeout */
 121         struct device           dev;
 122 };
 123 #define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
 124
 125 /* get and set the port private data pointer helper functions */
 126 static inline void *usb_get_serial_port_data(struct usb_serial_port *port)
 127 {
 128         return dev_get_drvdata(&port->dev);
 129 }
 130
 131 static inline void usb_set_serial_port_data(struct usb_serial_port *port,
 132                                             void *data)
 133 {
 134         dev_set_drvdata(&port->dev, data);
 135 }
 136
 137 /**
 138  * usb_serial - structure used by the usb-serial core for a device
 139  * @dev: pointer to the struct usb_device for this device
 140  * @type: pointer to the struct usb_serial_driver for this device
 141  * @interface: pointer to the struct usb_interface for this device
 142  * @num_ports: the number of ports this device has
 143  * @num_interrupt_in: number of interrupt in endpoints we have
 144  * @num_interrupt_out: number of interrupt out endpoints we have
 145  * @num_bulk_in: number of bulk in endpoints we have
 146  * @num_bulk_out: number of bulk out endpoints we have
 147  * @port: array of struct usb_serial_port structures for the different ports.
 148  * @private: place to put any driver specific information that is needed.  The
 149  *      usb-serial driver is required to manage this data, the usb-serial core
 150  *      will not touch this.  Use usb_get_serial_data() and
 151  *      usb_set_serial_data() to access this.
 152  */
 153 struct usb_serial {
 154         struct usb_device               *dev;
 155         struct usb_serial_driver        *type;
 156         struct usb_interface            *interface;
 157         unsigned char                   disconnected:1;
 158         unsigned char                   suspending:1;
 159         unsigned char                   attached:1;
 160         unsigned char                   minors_reserved:1;
 161         unsigned char                   num_ports;
 162         unsigned char                   num_port_pointers;
 163         unsigned char                   num_interrupt_in;
 164         unsigned char                   num_interrupt_out;
 165         unsigned char                   num_bulk_in;
 166         unsigned char                   num_bulk_out;
 167         struct usb_serial_port          *port[MAX_NUM_PORTS];
 168         struct kref                     kref;
 169         struct mutex                    disc_mutex;
 170         void                            *private;
 171 };
 172 #define to_usb_serial(d) container_of(d, struct usb_serial, kref)
 173
 174 /* get and set the serial private data pointer helper functions */
 175 static inline void *usb_get_serial_data(struct usb_serial *serial)
 176 {
 177         return serial->private;
 178 }
 179
 180 static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
 181 {
 182         serial->private = data;
 183 }
 184
 185 struct usb_serial_endpoints {
 186         unsigned char num_bulk_in;
 187         unsigned char num_bulk_out;
 188         unsigned char num_interrupt_in;
 189         unsigned char num_interrupt_out;
 190         struct usb_endpoint_descriptor *bulk_in[MAX_NUM_PORTS];
 191         struct usb_endpoint_descriptor *bulk_out[MAX_NUM_PORTS];
 192         struct usb_endpoint_descriptor *interrupt_in[MAX_NUM_PORTS];
 193         struct usb_endpoint_descriptor *interrupt_out[MAX_NUM_PORTS];
 194 };
 195
 196 /**
 197  * usb_serial_driver - describes a usb serial driver
 198  * @description: pointer to a string that describes this driver.  This string
 199  *      used in the syslog messages when a device is inserted or removed.
 200  * @id_table: pointer to a list of usb_device_id structures that define all
 201  *      of the devices this structure can support.
 202  * @num_ports: the number of different ports this device will have.
 203  * @num_bulk_in: minimum number of bulk-in endpoints
 204  * @num_bulk_out: minimum number of bulk-out endpoints
 205  * @num_interrupt_in: minimum number of interrupt-in endpoints
 206  * @num_interrupt_out: minimum number of interrupt-out endpoints
 207  * @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer
 208  *      (0 = end-point size)
 209  * @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size)
 210  * @calc_num_ports: pointer to a function to determine how many ports this
 211  *      device has dynamically. It can also be used to verify the number of
 212  *      endpoints or to modify the port-endpoint mapping. It will be called
 213  *      after the probe() callback is called, but before attach().
 214  * @probe: pointer to the driver's probe function.
 215  *      This will be called when the device is inserted into the system,
 216  *      but before the device has been fully initialized by the usb_serial
 217  *      subsystem.  Use this function to download any firmware to the device,
 218  *      or any other early initialization that might be needed.
 219  *      Return 0 to continue on with the initialization sequence.  Anything
 220  *      else will abort it.
 221  * @attach: pointer to the driver's attach function.
 222  *      This will be called when the struct usb_serial structure is fully set
 223  *      set up.  Do any local initialization of the device, or any private
 224  *      memory structure allocation at this point in time.
 225  * @disconnect: pointer to the driver's disconnect function.  This will be
 226  *      called when the device is unplugged or unbound from the driver.
 227  * @release: pointer to the driver's release function.  This will be called
 228  *      when the usb_serial data structure is about to be destroyed.
 229  * @usb_driver: pointer to the struct usb_driver that controls this
 230  *      device.  This is necessary to allow dynamic ids to be added to
 231  *      the driver from sysfs.
 232  *
 233  * This structure is defines a USB Serial driver.  It provides all of
 234  * the information that the USB serial core code needs.  If the function
 235  * pointers are defined, then the USB serial core code will call them when
 236  * the corresponding tty port functions are called.  If they are not
 237  * called, the generic serial function will be used instead.
 238  *
 239  * The driver.owner field should be set to the module owner of this driver.
 240  * The driver.name field should be set to the name of this driver (remember
 241  * it will show up in sysfs, so it needs to be short and to the point.
 242  * Using the module name is a good idea.)
 243  */
 244 struct usb_serial_driver {
 245         const char *description;
 246         const struct usb_device_id *id_table;
 247
 248         struct list_head        driver_list;
 249         struct device_driver    driver;
 250         struct usb_driver       *usb_driver;
 251         struct usb_dynids       dynids;
 252
 253         unsigned char           num_ports;
 254
 255         unsigned char           num_bulk_in;
 256         unsigned char           num_bulk_out;
 257         unsigned char           num_interrupt_in;
 258         unsigned char           num_interrupt_out;
 259
 260         size_t                  bulk_in_size;
 261         size_t                  bulk_out_size;
 262
 263         int (*probe)(struct usb_serial *serial, const struct usb_device_id *id);
 264         int (*attach)(struct usb_serial *serial);
 265         int (*calc_num_ports)(struct usb_serial *serial,
 266                         struct usb_serial_endpoints *epds);
 267
 268         void (*disconnect)(struct usb_serial *serial);
 269         void (*release)(struct usb_serial *serial);
 270
 271         int (*port_probe)(struct usb_serial_port *port);
 272         int (*port_remove)(struct usb_serial_port *port);
 273
 274         int (*suspend)(struct usb_serial *serial, pm_message_t message);
 275         int (*resume)(struct usb_serial *serial);
 276         int (*reset_resume)(struct usb_serial *serial);
 277
 278         /* serial function calls */
 279         /* Called by console and by the tty layer */
 280         int  (*open)(struct tty_struct *tty, struct usb_serial_port *port);
 281         void (*close)(struct usb_serial_port *port);
 282         int  (*write)(struct tty_struct *tty, struct usb_serial_port *port,
 283                         const unsigned char *buf, int count);
 284         /* Called only by the tty layer */
 285         int  (*write_room)(struct tty_struct *tty);
 286         int  (*ioctl)(struct tty_struct *tty,
 287                       unsigned int cmd, unsigned long arg);
 288         void (*set_termios)(struct tty_struct *tty,
 289                         struct usb_serial_port *port, struct ktermios *old);
 290         void (*break_ctl)(struct tty_struct *tty, int break_state);
 291         int  (*chars_in_buffer)(struct tty_struct *tty);
 292         void (*wait_until_sent)(struct tty_struct *tty, long timeout);
 293         bool (*tx_empty)(struct usb_serial_port *port);
 294         void (*throttle)(struct tty_struct *tty);
 295         void (*unthrottle)(struct tty_struct *tty);
 296         int  (*tiocmget)(struct tty_struct *tty);
 297         int  (*tiocmset)(struct tty_struct *tty,
 298                          unsigned int set, unsigned int clear);
 299         int  (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
 300         int  (*get_icount)(struct tty_struct *tty,
 301                         struct serial_icounter_struct *icount);
 302         /* Called by the tty layer for port level work. There may or may not
 303            be an attached tty at this point */
 304         void (*dtr_rts)(struct usb_serial_port *port, int on);
 305         int  (*carrier_raised)(struct usb_serial_port *port);
 306         /* Called by the usb serial hooks to allow the user to rework the
 307            termios state */
 308         void (*init_termios)(struct tty_struct *tty);
 309         /* USB events */
 310         void (*read_int_callback)(struct urb *urb);
 311         void (*write_int_callback)(struct urb *urb);
 312         void (*read_bulk_callback)(struct urb *urb);
 313         void (*write_bulk_callback)(struct urb *urb);
 314         /* Called by the generic read bulk callback */
 315         void (*process_read_urb)(struct urb *urb);
 316         /* Called by the generic write implementation */
 317         int (*prepare_write_buffer)(struct usb_serial_port *port,
 318                                                 void *dest, size_t size);
 319 };
 320 #define to_usb_serial_driver(d) \
 321         container_of(d, struct usb_serial_driver, driver)
 322
 323 extern int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
 324                 const char *name, const struct usb_device_id *id_table);
 325 extern void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
 326 extern void usb_serial_port_softint(struct usb_serial_port *port);
 327
 328 extern int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
 329 extern int usb_serial_resume(struct usb_interface *intf);
 330
 331 /* USB Serial console functions */
 332 #ifdef CONFIG_USB_SERIAL_CONSOLE
 333 extern void usb_serial_console_init(int minor);
 334 extern void usb_serial_console_exit(void);
 335 extern void usb_serial_console_disconnect(struct usb_serial *serial);
 336 #else
 337 static inline void usb_serial_console_init(int minor) { }
 338 static inline void usb_serial_console_exit(void) { }
 339 static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
 340 #endif
 341
 342 /* Functions needed by other parts of the usbserial core */
 343 extern struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
 344 extern void usb_serial_put(struct usb_serial *serial);
 345 extern int usb_serial_generic_open(struct tty_struct *tty,
 346         struct usb_serial_port *port);
 347 extern int usb_serial_generic_write_start(struct usb_serial_port *port,
 348                                                         gfp_t mem_flags);
 349 extern int usb_serial_generic_write(struct tty_struct *tty,
 350         struct usb_serial_port *port, const unsigned char *buf, int count);
 351 extern void usb_serial_generic_close(struct usb_serial_port *port);
 352 extern int usb_serial_generic_resume(struct usb_serial *serial);
 353 extern int usb_serial_generic_write_room(struct tty_struct *tty);
 354 extern int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
 355 extern void usb_serial_generic_wait_until_sent(struct tty_struct *tty,
 356                                                                 long timeout);
 357 extern void usb_serial_generic_read_bulk_callback(struct urb *urb);
 358 extern void usb_serial_generic_write_bulk_callback(struct urb *urb);
 359 extern void usb_serial_generic_throttle(struct tty_struct *tty);
 360 extern void usb_serial_generic_unthrottle(struct tty_struct *tty);
 361 extern int usb_serial_generic_tiocmiwait(struct tty_struct *tty,
 362                                                         unsigned long arg);
 363 extern int usb_serial_generic_get_icount(struct tty_struct *tty,
 364                                         struct serial_icounter_struct *icount);
 365 extern int usb_serial_generic_register(void);
 366 extern void usb_serial_generic_deregister(void);
 367 extern int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
 368                                                  gfp_t mem_flags);
 369 extern void usb_serial_generic_process_read_urb(struct urb *urb);
 370 extern int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
 371                                                 void *dest, size_t size);
 372 extern int usb_serial_handle_sysrq_char(struct usb_serial_port *port,
 373                                         unsigned int ch);
 374 extern int usb_serial_handle_break(struct usb_serial_port *port);
 375 extern void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
 376                                          struct tty_struct *tty,
 377                                          unsigned int status);
 378
 379
 380 extern int usb_serial_bus_register(struct usb_serial_driver *device);
 381 extern void usb_serial_bus_deregister(struct usb_serial_driver *device);
 382
 383 extern struct bus_type usb_serial_bus_type;
 384 extern struct tty_driver *usb_serial_tty_driver;
 385
 386 static inline void usb_serial_debug_data(struct device *dev,
 387                                          const char *function, int size,
 388                                          const unsigned char *data)
 389 {
 390         dev_dbg(dev, "%s - length = %d, data = %*ph\n",
 391                 function, size, size, data);
 392 }
 393
 394 /*
 395  * Macro for reporting errors in write path to avoid inifinite loop
 396  * when port is used as a console.
 397  */
 398 #define dev_err_console(usport, fmt, ...)                               \
 399 do {                                                                    \
 400         static bool __print_once;                                       \
 401         struct usb_serial_port *__port = (usport);                      \
 402                                                                         \
 403         if (!__port->port.console || !__print_once) {                   \
 404                 __print_once = true;                                    \
 405                 dev_err(&__port->dev, fmt, ##__VA_ARGS__);              \
 406         }                                                               \
 407 } while (0)
 408
 409 /*
 410  * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
 411  * @__serial_drivers: list of usb_serial drivers to register
 412  * @__ids: all device ids that @__serial_drivers bind to
 413  *
 414  * Helper macro for USB serial drivers which do not do anything special
 415  * in module init/exit. This eliminates a lot of boilerplate. Each
 416  * module may only use this macro once, and calling it replaces
 417  * module_init() and module_exit()
 418  *
 419  */
 420 #define usb_serial_module_driver(__name, __serial_drivers, __ids)       \
 421 static int __init usb_serial_module_init(void)                          \
 422 {                                                                       \
 423         return usb_serial_register_drivers(__serial_drivers,            \
 424                                            __name, __ids);              \
 425 }                                                                       \
 426 module_init(usb_serial_module_init);                                    \
 427 static void __exit usb_serial_module_exit(void)                         \
 428 {                                                                       \
 429         usb_serial_deregister_drivers(__serial_drivers);                \
 430 }                                                                       \
 431 module_exit(usb_serial_module_exit);
 432
 433 #define module_usb_serial_driver(__serial_drivers, __ids)               \
 434         usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
 435
 436 #endif /* __LINUX_USB_SERIAL_H */
 437