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  
9  #ifndef __LINUX_USB_SERIAL_H
10  #define __LINUX_USB_SERIAL_H
11  
12  #include <linux/kref.h>
13  #include <linux/mutex.h>
14  #include <linux/serial.h>
15  #include <linux/kfifo.h>
16  
17  /* The maximum number of ports one device can grab at once */
18  #define MAX_NUM_PORTS		16
19  
20  /* USB serial flags */
21  #define USB_SERIAL_WRITE_BUSY	0
22  #define USB_SERIAL_THROTTLED	1
23  
24  /**
25   * usb_serial_port: structure for the specific ports of a device.
26   * @serial: pointer back to the struct usb_serial owner of this port.
27   * @port: pointer to the corresponding tty_port for this port.
28   * @lock: spinlock to grab when updating portions of this structure.
29   * @minor: the minor number of the port
30   * @port_number: the struct usb_serial port number of this port (starts at 0)
31   * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
32   * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
33   * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
34   *	for this port.
35   * @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
36   * @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
37   * @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
38   * @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
39   *	for this port.
40   * @bulk_in_buffer: pointer to the bulk in buffer for this port.
41   * @bulk_in_size: the size of the bulk_in_buffer, in bytes.
42   * @read_urb: pointer to the bulk in struct urb for this port.
43   * @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
44   *	port.
45   * @bulk_in_buffers: pointers to the bulk in buffers for this port
46   * @read_urbs: pointers to the bulk in urbs for this port
47   * @read_urbs_free: status bitmap the for bulk in urbs
48   * @bulk_out_buffer: pointer to the bulk out buffer for this port.
49   * @bulk_out_size: the size of the bulk_out_buffer, in bytes.
50   * @write_urb: pointer to the bulk out struct urb for this port.
51   * @write_fifo: kfifo used to buffer outgoing data
52   * @bulk_out_buffers: pointers to the bulk out buffers for this port
53   * @write_urbs: pointers to the bulk out urbs for this port
54   * @write_urbs_free: status bitmap the for bulk out urbs
55   * @icount: interrupt counters
56   * @tx_bytes: number of bytes currently in host stack queues
57   * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
58   *	port.
59   * @flags: usb serial port flags
60   * @work: work queue entry for the line discipline waking up.
61   * @dev: pointer to the serial device
62   *
63   * This structure is used by the usb-serial core and drivers for the specific
64   * ports of a device.
65   */
66  struct usb_serial_port {
67  	struct usb_serial	*serial;
68  	struct tty_port		port;
69  	spinlock_t		lock;
70  	u32			minor;
71  	u8			port_number;
72  
73  	unsigned char		*interrupt_in_buffer;
74  	struct urb		*interrupt_in_urb;
75  	__u8			interrupt_in_endpointAddress;
76  
77  	unsigned char		*interrupt_out_buffer;
78  	int			interrupt_out_size;
79  	struct urb		*interrupt_out_urb;
80  	__u8			interrupt_out_endpointAddress;
81  
82  	unsigned char		*bulk_in_buffer;
83  	int			bulk_in_size;
84  	struct urb		*read_urb;
85  	__u8			bulk_in_endpointAddress;
86  
87  	unsigned char		*bulk_in_buffers[2];
88  	struct urb		*read_urbs[2];
89  	unsigned long		read_urbs_free;
90  
91  	unsigned char		*bulk_out_buffer;
92  	int			bulk_out_size;
93  	struct urb		*write_urb;
94  	struct kfifo		write_fifo;
95  
96  	unsigned char		*bulk_out_buffers[2];
97  	struct urb		*write_urbs[2];
98  	unsigned long		write_urbs_free;
99  	__u8			bulk_out_endpointAddress;
100  
101  	struct async_icount	icount;
102  	int			tx_bytes;
103  
104  	unsigned long		flags;
105  	struct work_struct	work;
106  	unsigned long		sysrq; /* sysrq timeout */
107  	struct device		dev;
108  };
109  #define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
110  
111  /* get and set the port private data pointer helper functions */
usb_get_serial_port_data(struct usb_serial_port * port)112  static inline void *usb_get_serial_port_data(struct usb_serial_port *port)
113  {
114  	return dev_get_drvdata(&port->dev);
115  }
116  
usb_set_serial_port_data(struct usb_serial_port * port,void * data)117  static inline void usb_set_serial_port_data(struct usb_serial_port *port,
118  					    void *data)
119  {
120  	dev_set_drvdata(&port->dev, data);
121  }
122  
123  /**
124   * usb_serial - structure used by the usb-serial core for a device
125   * @dev: pointer to the struct usb_device for this device
126   * @type: pointer to the struct usb_serial_driver for this device
127   * @interface: pointer to the struct usb_interface for this device
128   * @sibling: pointer to the struct usb_interface of any sibling interface
129   * @suspend_count: number of suspended (sibling) interfaces
130   * @num_ports: the number of ports this device has
131   * @num_interrupt_in: number of interrupt in endpoints we have
132   * @num_interrupt_out: number of interrupt out endpoints we have
133   * @num_bulk_in: number of bulk in endpoints we have
134   * @num_bulk_out: number of bulk out endpoints we have
135   * @port: array of struct usb_serial_port structures for the different ports.
136   * @private: place to put any driver specific information that is needed.  The
137   *	usb-serial driver is required to manage this data, the usb-serial core
138   *	will not touch this.  Use usb_get_serial_data() and
139   *	usb_set_serial_data() to access this.
140   */
141  struct usb_serial {
142  	struct usb_device		*dev;
143  	struct usb_serial_driver	*type;
144  	struct usb_interface		*interface;
145  	struct usb_interface		*sibling;
146  	unsigned int			suspend_count;
147  	unsigned char			disconnected:1;
148  	unsigned char			attached:1;
149  	unsigned char			minors_reserved:1;
150  	unsigned char			num_ports;
151  	unsigned char			num_port_pointers;
152  	unsigned char			num_interrupt_in;
153  	unsigned char			num_interrupt_out;
154  	unsigned char			num_bulk_in;
155  	unsigned char			num_bulk_out;
156  	struct usb_serial_port		*port[MAX_NUM_PORTS];
157  	struct kref			kref;
158  	struct mutex			disc_mutex;
159  	void				*private;
160  };
161  #define to_usb_serial(d) container_of(d, struct usb_serial, kref)
162  
163  /* get and set the serial private data pointer helper functions */
usb_get_serial_data(struct usb_serial * serial)164  static inline void *usb_get_serial_data(struct usb_serial *serial)
165  {
166  	return serial->private;
167  }
168  
usb_set_serial_data(struct usb_serial * serial,void * data)169  static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
170  {
171  	serial->private = data;
172  }
173  
174  struct usb_serial_endpoints {
175  	unsigned char num_bulk_in;
176  	unsigned char num_bulk_out;
177  	unsigned char num_interrupt_in;
178  	unsigned char num_interrupt_out;
179  	struct usb_endpoint_descriptor *bulk_in[MAX_NUM_PORTS];
180  	struct usb_endpoint_descriptor *bulk_out[MAX_NUM_PORTS];
181  	struct usb_endpoint_descriptor *interrupt_in[MAX_NUM_PORTS];
182  	struct usb_endpoint_descriptor *interrupt_out[MAX_NUM_PORTS];
183  };
184  
185  /**
186   * usb_serial_driver - describes a usb serial driver
187   * @description: pointer to a string that describes this driver.  This string
188   *	used in the syslog messages when a device is inserted or removed.
189   * @id_table: pointer to a list of usb_device_id structures that define all
190   *	of the devices this structure can support.
191   * @num_ports: the number of different ports this device will have.
192   * @num_bulk_in: minimum number of bulk-in endpoints
193   * @num_bulk_out: minimum number of bulk-out endpoints
194   * @num_interrupt_in: minimum number of interrupt-in endpoints
195   * @num_interrupt_out: minimum number of interrupt-out endpoints
196   * @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer
197   *	(0 = end-point size)
198   * @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size)
199   * @calc_num_ports: pointer to a function to determine how many ports this
200   *	device has dynamically. It can also be used to verify the number of
201   *	endpoints or to modify the port-endpoint mapping. It will be called
202   *	after the probe() callback is called, but before attach().
203   * @probe: pointer to the driver's probe function.
204   *	This will be called when the device is inserted into the system,
205   *	but before the device has been fully initialized by the usb_serial
206   *	subsystem.  Use this function to download any firmware to the device,
207   *	or any other early initialization that might be needed.
208   *	Return 0 to continue on with the initialization sequence.  Anything
209   *	else will abort it.
210   * @attach: pointer to the driver's attach function.
211   *	This will be called when the struct usb_serial structure is fully
212   *	set up.  Do any local initialization of the device, or any private
213   *	memory structure allocation at this point in time.
214   * @disconnect: pointer to the driver's disconnect function.  This will be
215   *	called when the device is unplugged or unbound from the driver.
216   * @release: pointer to the driver's release function.  This will be called
217   *	when the usb_serial data structure is about to be destroyed.
218   * @usb_driver: pointer to the struct usb_driver that controls this
219   *	device.  This is necessary to allow dynamic ids to be added to
220   *	the driver from sysfs.
221   *
222   * This structure is defines a USB Serial driver.  It provides all of
223   * the information that the USB serial core code needs.  If the function
224   * pointers are defined, then the USB serial core code will call them when
225   * the corresponding tty port functions are called.  If they are not
226   * called, the generic serial function will be used instead.
227   *
228   * The driver.owner field should be set to the module owner of this driver.
229   * The driver.name field should be set to the name of this driver (remember
230   * it will show up in sysfs, so it needs to be short and to the point.
231   * Using the module name is a good idea.)
232   */
233  struct usb_serial_driver {
234  	const char *description;
235  	const struct usb_device_id *id_table;
236  
237  	struct list_head	driver_list;
238  	struct device_driver	driver;
239  	struct usb_driver	*usb_driver;
240  	struct usb_dynids	dynids;
241  
242  	unsigned char		num_ports;
243  
244  	unsigned char		num_bulk_in;
245  	unsigned char		num_bulk_out;
246  	unsigned char		num_interrupt_in;
247  	unsigned char		num_interrupt_out;
248  
249  	size_t			bulk_in_size;
250  	size_t			bulk_out_size;
251  
252  	int (*probe)(struct usb_serial *serial, const struct usb_device_id *id);
253  	int (*attach)(struct usb_serial *serial);
254  	int (*calc_num_ports)(struct usb_serial *serial,
255  			struct usb_serial_endpoints *epds);
256  
257  	void (*disconnect)(struct usb_serial *serial);
258  	void (*release)(struct usb_serial *serial);
259  
260  	int (*port_probe)(struct usb_serial_port *port);
261  	void (*port_remove)(struct usb_serial_port *port);
262  
263  	int (*suspend)(struct usb_serial *serial, pm_message_t message);
264  	int (*resume)(struct usb_serial *serial);
265  	int (*reset_resume)(struct usb_serial *serial);
266  
267  	/* serial function calls */
268  	/* Called by console and by the tty layer */
269  	int  (*open)(struct tty_struct *tty, struct usb_serial_port *port);
270  	void (*close)(struct usb_serial_port *port);
271  	int  (*write)(struct tty_struct *tty, struct usb_serial_port *port,
272  			const unsigned char *buf, int count);
273  	/* Called only by the tty layer */
274  	unsigned int (*write_room)(struct tty_struct *tty);
275  	int  (*ioctl)(struct tty_struct *tty,
276  		      unsigned int cmd, unsigned long arg);
277  	void (*get_serial)(struct tty_struct *tty, struct serial_struct *ss);
278  	int  (*set_serial)(struct tty_struct *tty, struct serial_struct *ss);
279  	void (*set_termios)(struct tty_struct *tty, struct usb_serial_port *port,
280  			    const struct ktermios *old);
281  	int (*break_ctl)(struct tty_struct *tty, int break_state);
282  	unsigned int (*chars_in_buffer)(struct tty_struct *tty);
283  	void (*wait_until_sent)(struct tty_struct *tty, long timeout);
284  	bool (*tx_empty)(struct usb_serial_port *port);
285  	void (*throttle)(struct tty_struct *tty);
286  	void (*unthrottle)(struct tty_struct *tty);
287  	int  (*tiocmget)(struct tty_struct *tty);
288  	int  (*tiocmset)(struct tty_struct *tty,
289  			 unsigned int set, unsigned int clear);
290  	int  (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
291  	int  (*get_icount)(struct tty_struct *tty,
292  			struct serial_icounter_struct *icount);
293  	/* Called by the tty layer for port level work. There may or may not
294  	   be an attached tty at this point */
295  	void (*dtr_rts)(struct usb_serial_port *port, int on);
296  	int  (*carrier_raised)(struct usb_serial_port *port);
297  	/* Called by the usb serial hooks to allow the user to rework the
298  	   termios state */
299  	void (*init_termios)(struct tty_struct *tty);
300  	/* USB events */
301  	void (*read_int_callback)(struct urb *urb);
302  	void (*write_int_callback)(struct urb *urb);
303  	void (*read_bulk_callback)(struct urb *urb);
304  	void (*write_bulk_callback)(struct urb *urb);
305  	/* Called by the generic read bulk callback */
306  	void (*process_read_urb)(struct urb *urb);
307  	/* Called by the generic write implementation */
308  	int (*prepare_write_buffer)(struct usb_serial_port *port,
309  						void *dest, size_t size);
310  };
311  #define to_usb_serial_driver(d) \
312  	container_of(d, struct usb_serial_driver, driver)
313  
314  #define usb_serial_register_drivers(serial_drivers, name, id_table) \
315  	__usb_serial_register_drivers(serial_drivers, THIS_MODULE, name, id_table)
316  int __usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
317  				  struct module *owner, const char *name,
318  				  const struct usb_device_id *id_table);
319  void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
320  void usb_serial_port_softint(struct usb_serial_port *port);
321  
322  int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
323  int usb_serial_resume(struct usb_interface *intf);
324  
325  /* USB Serial console functions */
326  #ifdef CONFIG_USB_SERIAL_CONSOLE
327  void usb_serial_console_init(int minor);
328  void usb_serial_console_exit(void);
329  void usb_serial_console_disconnect(struct usb_serial *serial);
330  #else
usb_serial_console_init(int minor)331  static inline void usb_serial_console_init(int minor) { }
usb_serial_console_exit(void)332  static inline void usb_serial_console_exit(void) { }
usb_serial_console_disconnect(struct usb_serial * serial)333  static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
334  #endif
335  
336  /* Functions needed by other parts of the usbserial core */
337  struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
338  void usb_serial_put(struct usb_serial *serial);
339  
340  int usb_serial_claim_interface(struct usb_serial *serial, struct usb_interface *intf);
341  
342  int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port);
343  int usb_serial_generic_write_start(struct usb_serial_port *port, gfp_t mem_flags);
344  int usb_serial_generic_write(struct tty_struct *tty, struct usb_serial_port *port,
345  		const unsigned char *buf, int count);
346  void usb_serial_generic_close(struct usb_serial_port *port);
347  int usb_serial_generic_resume(struct usb_serial *serial);
348  unsigned int usb_serial_generic_write_room(struct tty_struct *tty);
349  unsigned int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
350  void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout);
351  void usb_serial_generic_read_bulk_callback(struct urb *urb);
352  void usb_serial_generic_write_bulk_callback(struct urb *urb);
353  void usb_serial_generic_throttle(struct tty_struct *tty);
354  void usb_serial_generic_unthrottle(struct tty_struct *tty);
355  int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg);
356  int usb_serial_generic_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount);
357  int usb_serial_generic_register(void);
358  void usb_serial_generic_deregister(void);
359  int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port, gfp_t mem_flags);
360  void usb_serial_generic_process_read_urb(struct urb *urb);
361  int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port, void *dest, size_t size);
362  
363  #if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
364  int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch);
365  int usb_serial_handle_break(struct usb_serial_port *port);
366  #else
usb_serial_handle_sysrq_char(struct usb_serial_port * port,unsigned int ch)367  static inline int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
368  {
369  	return 0;
370  }
usb_serial_handle_break(struct usb_serial_port * port)371  static inline int usb_serial_handle_break(struct usb_serial_port *port)
372  {
373  	return 0;
374  }
375  #endif
376  
377  void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
378  		struct tty_struct *tty, unsigned int status);
379  
380  
381  int usb_serial_bus_register(struct usb_serial_driver *device);
382  void usb_serial_bus_deregister(struct usb_serial_driver *device);
383  
384  extern const struct bus_type usb_serial_bus_type;
385  extern struct tty_driver *usb_serial_tty_driver;
386  
usb_serial_debug_data(struct device * dev,const char * function,int size,const unsigned char * data)387  static inline void usb_serial_debug_data(struct device *dev,
388  					 const char *function, int size,
389  					 const unsigned char *data)
390  {
391  	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
392  		function, size, size, data);
393  }
394  
395  /*
396   * Macro for reporting errors in write path to avoid infinite loop
397   * when port is used as a console.
398   */
399  #define dev_err_console(usport, fmt, ...)				\
400  do {									\
401  	static bool __print_once;					\
402  	struct usb_serial_port *__port = (usport);			\
403  									\
404  	if (!__port->port.console || !__print_once) {			\
405  		__print_once = true;					\
406  		dev_err(&__port->dev, fmt, ##__VA_ARGS__);		\
407  	}								\
408  } while (0)
409  
410  /*
411   * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
412   * @__serial_drivers: list of usb_serial drivers to register
413   * @__ids: all device ids that @__serial_drivers bind to
414   *
415   * Helper macro for USB serial drivers which do not do anything special
416   * in module init/exit. This eliminates a lot of boilerplate. Each
417   * module may only use this macro once, and calling it replaces
418   * module_init() and module_exit()
419   *
420   */
421  #define usb_serial_module_driver(__name, __serial_drivers, __ids)	\
422  static int __init usb_serial_module_init(void)				\
423  {									\
424  	return usb_serial_register_drivers(__serial_drivers,		\
425  					   __name, __ids);		\
426  }									\
427  module_init(usb_serial_module_init);					\
428  static void __exit usb_serial_module_exit(void)				\
429  {									\
430  	usb_serial_deregister_drivers(__serial_drivers);		\
431  }									\
432  module_exit(usb_serial_module_exit);
433  
434  #define module_usb_serial_driver(__serial_drivers, __ids)		\
435  	usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
436  
437  #endif /* __LINUX_USB_SERIAL_H */
438  
439