xref: /linux/include/linux/usb/serial.h (revision 44f57d78)
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 /* USB serial flags */
27 #define USB_SERIAL_WRITE_BUSY	0
28 #define USB_SERIAL_THROTTLED	1
29 
30 /**
31  * usb_serial_port: structure for the specific ports of a device.
32  * @serial: pointer back to the struct usb_serial owner of this port.
33  * @port: pointer to the corresponding tty_port for this port.
34  * @lock: spinlock to grab when updating portions of this structure.
35  * @minor: the minor number of the port
36  * @port_number: the struct usb_serial port number of this port (starts at 0)
37  * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
38  * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
39  * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
40  *	for this port.
41  * @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
42  * @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
43  * @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
44  * @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
45  *	for this port.
46  * @bulk_in_buffer: pointer to the bulk in buffer for this port.
47  * @bulk_in_size: the size of the bulk_in_buffer, in bytes.
48  * @read_urb: pointer to the bulk in struct urb for this port.
49  * @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
50  *	port.
51  * @bulk_in_buffers: pointers to the bulk in buffers for this port
52  * @read_urbs: pointers to the bulk in urbs for this port
53  * @read_urbs_free: status bitmap the for bulk in urbs
54  * @bulk_out_buffer: pointer to the bulk out buffer for this port.
55  * @bulk_out_size: the size of the bulk_out_buffer, in bytes.
56  * @write_urb: pointer to the bulk out struct urb for this port.
57  * @write_fifo: kfifo used to buffer outgoing data
58  * @bulk_out_buffers: pointers to the bulk out buffers for this port
59  * @write_urbs: pointers to the bulk out urbs for this port
60  * @write_urbs_free: status bitmap the for bulk out urbs
61  * @icount: interrupt counters
62  * @tx_bytes: number of bytes currently in host stack queues
63  * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
64  *	port.
65  * @flags: usb serial port flags
66  * @write_wait: a wait_queue_head_t used by the port.
67  * @work: work queue entry for the line discipline waking up.
68  * @dev: pointer to the serial device
69  *
70  * This structure is used by the usb-serial core and drivers for the specific
71  * ports of a device.
72  */
73 struct usb_serial_port {
74 	struct usb_serial	*serial;
75 	struct tty_port		port;
76 	spinlock_t		lock;
77 	u32			minor;
78 	u8			port_number;
79 
80 	unsigned char		*interrupt_in_buffer;
81 	struct urb		*interrupt_in_urb;
82 	__u8			interrupt_in_endpointAddress;
83 
84 	unsigned char		*interrupt_out_buffer;
85 	int			interrupt_out_size;
86 	struct urb		*interrupt_out_urb;
87 	__u8			interrupt_out_endpointAddress;
88 
89 	unsigned char		*bulk_in_buffer;
90 	int			bulk_in_size;
91 	struct urb		*read_urb;
92 	__u8			bulk_in_endpointAddress;
93 
94 	unsigned char		*bulk_in_buffers[2];
95 	struct urb		*read_urbs[2];
96 	unsigned long		read_urbs_free;
97 
98 	unsigned char		*bulk_out_buffer;
99 	int			bulk_out_size;
100 	struct urb		*write_urb;
101 	struct kfifo		write_fifo;
102 
103 	unsigned char		*bulk_out_buffers[2];
104 	struct urb		*write_urbs[2];
105 	unsigned long		write_urbs_free;
106 	__u8			bulk_out_endpointAddress;
107 
108 	struct async_icount	icount;
109 	int			tx_bytes;
110 
111 	unsigned long		flags;
112 	wait_queue_head_t	write_wait;
113 	struct work_struct	work;
114 	unsigned long		sysrq; /* sysrq timeout */
115 	struct device		dev;
116 };
117 #define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
118 
119 /* get and set the port private data pointer helper functions */
120 static inline void *usb_get_serial_port_data(struct usb_serial_port *port)
121 {
122 	return dev_get_drvdata(&port->dev);
123 }
124 
125 static inline void usb_set_serial_port_data(struct usb_serial_port *port,
126 					    void *data)
127 {
128 	dev_set_drvdata(&port->dev, data);
129 }
130 
131 /**
132  * usb_serial - structure used by the usb-serial core for a device
133  * @dev: pointer to the struct usb_device for this device
134  * @type: pointer to the struct usb_serial_driver for this device
135  * @interface: pointer to the struct usb_interface for this device
136  * @num_ports: the number of ports this device has
137  * @num_interrupt_in: number of interrupt in endpoints we have
138  * @num_interrupt_out: number of interrupt out endpoints we have
139  * @num_bulk_in: number of bulk in endpoints we have
140  * @num_bulk_out: number of bulk out endpoints we have
141  * @port: array of struct usb_serial_port structures for the different ports.
142  * @private: place to put any driver specific information that is needed.  The
143  *	usb-serial driver is required to manage this data, the usb-serial core
144  *	will not touch this.  Use usb_get_serial_data() and
145  *	usb_set_serial_data() to access this.
146  */
147 struct usb_serial {
148 	struct usb_device		*dev;
149 	struct usb_serial_driver	*type;
150 	struct usb_interface		*interface;
151 	unsigned char			disconnected:1;
152 	unsigned char			suspending:1;
153 	unsigned char			attached:1;
154 	unsigned char			minors_reserved:1;
155 	unsigned char			num_ports;
156 	unsigned char			num_port_pointers;
157 	unsigned char			num_interrupt_in;
158 	unsigned char			num_interrupt_out;
159 	unsigned char			num_bulk_in;
160 	unsigned char			num_bulk_out;
161 	struct usb_serial_port		*port[MAX_NUM_PORTS];
162 	struct kref			kref;
163 	struct mutex			disc_mutex;
164 	void				*private;
165 };
166 #define to_usb_serial(d) container_of(d, struct usb_serial, kref)
167 
168 /* get and set the serial private data pointer helper functions */
169 static inline void *usb_get_serial_data(struct usb_serial *serial)
170 {
171 	return serial->private;
172 }
173 
174 static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
175 {
176 	serial->private = data;
177 }
178 
179 struct usb_serial_endpoints {
180 	unsigned char num_bulk_in;
181 	unsigned char num_bulk_out;
182 	unsigned char num_interrupt_in;
183 	unsigned char num_interrupt_out;
184 	struct usb_endpoint_descriptor *bulk_in[MAX_NUM_PORTS];
185 	struct usb_endpoint_descriptor *bulk_out[MAX_NUM_PORTS];
186 	struct usb_endpoint_descriptor *interrupt_in[MAX_NUM_PORTS];
187 	struct usb_endpoint_descriptor *interrupt_out[MAX_NUM_PORTS];
188 };
189 
190 /**
191  * usb_serial_driver - describes a usb serial driver
192  * @description: pointer to a string that describes this driver.  This string
193  *	used in the syslog messages when a device is inserted or removed.
194  * @id_table: pointer to a list of usb_device_id structures that define all
195  *	of the devices this structure can support.
196  * @num_ports: the number of different ports this device will have.
197  * @num_bulk_in: minimum number of bulk-in endpoints
198  * @num_bulk_out: minimum number of bulk-out endpoints
199  * @num_interrupt_in: minimum number of interrupt-in endpoints
200  * @num_interrupt_out: minimum number of interrupt-out endpoints
201  * @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer
202  *	(0 = end-point size)
203  * @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size)
204  * @calc_num_ports: pointer to a function to determine how many ports this
205  *	device has dynamically. It can also be used to verify the number of
206  *	endpoints or to modify the port-endpoint mapping. It will be called
207  *	after the probe() callback is called, but before attach().
208  * @probe: pointer to the driver's probe function.
209  *	This will be called when the device is inserted into the system,
210  *	but before the device has been fully initialized by the usb_serial
211  *	subsystem.  Use this function to download any firmware to the device,
212  *	or any other early initialization that might be needed.
213  *	Return 0 to continue on with the initialization sequence.  Anything
214  *	else will abort it.
215  * @attach: pointer to the driver's attach function.
216  *	This will be called when the struct usb_serial structure is fully set
217  *	set up.  Do any local initialization of the device, or any private
218  *	memory structure allocation at this point in time.
219  * @disconnect: pointer to the driver's disconnect function.  This will be
220  *	called when the device is unplugged or unbound from the driver.
221  * @release: pointer to the driver's release function.  This will be called
222  *	when the usb_serial data structure is about to be destroyed.
223  * @usb_driver: pointer to the struct usb_driver that controls this
224  *	device.  This is necessary to allow dynamic ids to be added to
225  *	the driver from sysfs.
226  *
227  * This structure is defines a USB Serial driver.  It provides all of
228  * the information that the USB serial core code needs.  If the function
229  * pointers are defined, then the USB serial core code will call them when
230  * the corresponding tty port functions are called.  If they are not
231  * called, the generic serial function will be used instead.
232  *
233  * The driver.owner field should be set to the module owner of this driver.
234  * The driver.name field should be set to the name of this driver (remember
235  * it will show up in sysfs, so it needs to be short and to the point.
236  * Using the module name is a good idea.)
237  */
238 struct usb_serial_driver {
239 	const char *description;
240 	const struct usb_device_id *id_table;
241 
242 	struct list_head	driver_list;
243 	struct device_driver	driver;
244 	struct usb_driver	*usb_driver;
245 	struct usb_dynids	dynids;
246 
247 	unsigned char		num_ports;
248 
249 	unsigned char		num_bulk_in;
250 	unsigned char		num_bulk_out;
251 	unsigned char		num_interrupt_in;
252 	unsigned char		num_interrupt_out;
253 
254 	size_t			bulk_in_size;
255 	size_t			bulk_out_size;
256 
257 	int (*probe)(struct usb_serial *serial, const struct usb_device_id *id);
258 	int (*attach)(struct usb_serial *serial);
259 	int (*calc_num_ports)(struct usb_serial *serial,
260 			struct usb_serial_endpoints *epds);
261 
262 	void (*disconnect)(struct usb_serial *serial);
263 	void (*release)(struct usb_serial *serial);
264 
265 	int (*port_probe)(struct usb_serial_port *port);
266 	int (*port_remove)(struct usb_serial_port *port);
267 
268 	int (*suspend)(struct usb_serial *serial, pm_message_t message);
269 	int (*resume)(struct usb_serial *serial);
270 	int (*reset_resume)(struct usb_serial *serial);
271 
272 	/* serial function calls */
273 	/* Called by console and by the tty layer */
274 	int  (*open)(struct tty_struct *tty, struct usb_serial_port *port);
275 	void (*close)(struct usb_serial_port *port);
276 	int  (*write)(struct tty_struct *tty, struct usb_serial_port *port,
277 			const unsigned char *buf, int count);
278 	/* Called only by the tty layer */
279 	int  (*write_room)(struct tty_struct *tty);
280 	int  (*ioctl)(struct tty_struct *tty,
281 		      unsigned int cmd, unsigned long arg);
282 	int  (*get_serial)(struct tty_struct *tty, struct serial_struct *ss);
283 	int  (*set_serial)(struct tty_struct *tty, struct serial_struct *ss);
284 	void (*set_termios)(struct tty_struct *tty,
285 			struct usb_serial_port *port, struct ktermios *old);
286 	void (*break_ctl)(struct tty_struct *tty, int break_state);
287 	int  (*chars_in_buffer)(struct tty_struct *tty);
288 	void (*wait_until_sent)(struct tty_struct *tty, long timeout);
289 	bool (*tx_empty)(struct usb_serial_port *port);
290 	void (*throttle)(struct tty_struct *tty);
291 	void (*unthrottle)(struct tty_struct *tty);
292 	int  (*tiocmget)(struct tty_struct *tty);
293 	int  (*tiocmset)(struct tty_struct *tty,
294 			 unsigned int set, unsigned int clear);
295 	int  (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
296 	int  (*get_icount)(struct tty_struct *tty,
297 			struct serial_icounter_struct *icount);
298 	/* Called by the tty layer for port level work. There may or may not
299 	   be an attached tty at this point */
300 	void (*dtr_rts)(struct usb_serial_port *port, int on);
301 	int  (*carrier_raised)(struct usb_serial_port *port);
302 	/* Called by the usb serial hooks to allow the user to rework the
303 	   termios state */
304 	void (*init_termios)(struct tty_struct *tty);
305 	/* USB events */
306 	void (*read_int_callback)(struct urb *urb);
307 	void (*write_int_callback)(struct urb *urb);
308 	void (*read_bulk_callback)(struct urb *urb);
309 	void (*write_bulk_callback)(struct urb *urb);
310 	/* Called by the generic read bulk callback */
311 	void (*process_read_urb)(struct urb *urb);
312 	/* Called by the generic write implementation */
313 	int (*prepare_write_buffer)(struct usb_serial_port *port,
314 						void *dest, size_t size);
315 };
316 #define to_usb_serial_driver(d) \
317 	container_of(d, struct usb_serial_driver, driver)
318 
319 extern int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
320 		const char *name, const struct usb_device_id *id_table);
321 extern void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
322 extern void usb_serial_port_softint(struct usb_serial_port *port);
323 
324 extern int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
325 extern int usb_serial_resume(struct usb_interface *intf);
326 
327 /* USB Serial console functions */
328 #ifdef CONFIG_USB_SERIAL_CONSOLE
329 extern void usb_serial_console_init(int minor);
330 extern void usb_serial_console_exit(void);
331 extern void usb_serial_console_disconnect(struct usb_serial *serial);
332 #else
333 static inline void usb_serial_console_init(int minor) { }
334 static inline void usb_serial_console_exit(void) { }
335 static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
336 #endif
337 
338 /* Functions needed by other parts of the usbserial core */
339 extern struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
340 extern void usb_serial_put(struct usb_serial *serial);
341 extern int usb_serial_generic_open(struct tty_struct *tty,
342 	struct usb_serial_port *port);
343 extern int usb_serial_generic_write_start(struct usb_serial_port *port,
344 							gfp_t mem_flags);
345 extern int usb_serial_generic_write(struct tty_struct *tty,
346 	struct usb_serial_port *port, const unsigned char *buf, int count);
347 extern void usb_serial_generic_close(struct usb_serial_port *port);
348 extern int usb_serial_generic_resume(struct usb_serial *serial);
349 extern int usb_serial_generic_write_room(struct tty_struct *tty);
350 extern int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
351 extern void usb_serial_generic_wait_until_sent(struct tty_struct *tty,
352 								long timeout);
353 extern void usb_serial_generic_read_bulk_callback(struct urb *urb);
354 extern void usb_serial_generic_write_bulk_callback(struct urb *urb);
355 extern void usb_serial_generic_throttle(struct tty_struct *tty);
356 extern void usb_serial_generic_unthrottle(struct tty_struct *tty);
357 extern int usb_serial_generic_tiocmiwait(struct tty_struct *tty,
358 							unsigned long arg);
359 extern int usb_serial_generic_get_icount(struct tty_struct *tty,
360 					struct serial_icounter_struct *icount);
361 extern int usb_serial_generic_register(void);
362 extern void usb_serial_generic_deregister(void);
363 extern int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
364 						 gfp_t mem_flags);
365 extern void usb_serial_generic_process_read_urb(struct urb *urb);
366 extern int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
367 						void *dest, size_t size);
368 extern int usb_serial_handle_sysrq_char(struct usb_serial_port *port,
369 					unsigned int ch);
370 extern int usb_serial_handle_break(struct usb_serial_port *port);
371 extern void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
372 					 struct tty_struct *tty,
373 					 unsigned int status);
374 
375 
376 extern int usb_serial_bus_register(struct usb_serial_driver *device);
377 extern void usb_serial_bus_deregister(struct usb_serial_driver *device);
378 
379 extern struct bus_type usb_serial_bus_type;
380 extern struct tty_driver *usb_serial_tty_driver;
381 
382 static inline void usb_serial_debug_data(struct device *dev,
383 					 const char *function, int size,
384 					 const unsigned char *data)
385 {
386 	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
387 		function, size, size, data);
388 }
389 
390 /*
391  * Macro for reporting errors in write path to avoid inifinite loop
392  * when port is used as a console.
393  */
394 #define dev_err_console(usport, fmt, ...)				\
395 do {									\
396 	static bool __print_once;					\
397 	struct usb_serial_port *__port = (usport);			\
398 									\
399 	if (!__port->port.console || !__print_once) {			\
400 		__print_once = true;					\
401 		dev_err(&__port->dev, fmt, ##__VA_ARGS__);		\
402 	}								\
403 } while (0)
404 
405 /*
406  * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
407  * @__serial_drivers: list of usb_serial drivers to register
408  * @__ids: all device ids that @__serial_drivers bind to
409  *
410  * Helper macro for USB serial drivers which do not do anything special
411  * in module init/exit. This eliminates a lot of boilerplate. Each
412  * module may only use this macro once, and calling it replaces
413  * module_init() and module_exit()
414  *
415  */
416 #define usb_serial_module_driver(__name, __serial_drivers, __ids)	\
417 static int __init usb_serial_module_init(void)				\
418 {									\
419 	return usb_serial_register_drivers(__serial_drivers,		\
420 					   __name, __ids);		\
421 }									\
422 module_init(usb_serial_module_init);					\
423 static void __exit usb_serial_module_exit(void)				\
424 {									\
425 	usb_serial_deregister_drivers(__serial_drivers);		\
426 }									\
427 module_exit(usb_serial_module_exit);
428 
429 #define module_usb_serial_driver(__serial_drivers, __ids)		\
430 	usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
431 
432 #endif /* __LINUX_USB_SERIAL_H */
433 
434