xref: /linux/include/linux/usb/serial.h (revision be709d48329a500621d2a05835283150ae137b45)
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 	int  (*get_serial)(struct tty_struct *tty, struct serial_struct *ss);
289 	int  (*set_serial)(struct tty_struct *tty, struct serial_struct *ss);
290 	void (*set_termios)(struct tty_struct *tty,
291 			struct usb_serial_port *port, struct ktermios *old);
292 	void (*break_ctl)(struct tty_struct *tty, int break_state);
293 	int  (*chars_in_buffer)(struct tty_struct *tty);
294 	void (*wait_until_sent)(struct tty_struct *tty, long timeout);
295 	bool (*tx_empty)(struct usb_serial_port *port);
296 	void (*throttle)(struct tty_struct *tty);
297 	void (*unthrottle)(struct tty_struct *tty);
298 	int  (*tiocmget)(struct tty_struct *tty);
299 	int  (*tiocmset)(struct tty_struct *tty,
300 			 unsigned int set, unsigned int clear);
301 	int  (*tiocmiwait)(struct tty_struct *tty, unsigned long arg);
302 	int  (*get_icount)(struct tty_struct *tty,
303 			struct serial_icounter_struct *icount);
304 	/* Called by the tty layer for port level work. There may or may not
305 	   be an attached tty at this point */
306 	void (*dtr_rts)(struct usb_serial_port *port, int on);
307 	int  (*carrier_raised)(struct usb_serial_port *port);
308 	/* Called by the usb serial hooks to allow the user to rework the
309 	   termios state */
310 	void (*init_termios)(struct tty_struct *tty);
311 	/* USB events */
312 	void (*read_int_callback)(struct urb *urb);
313 	void (*write_int_callback)(struct urb *urb);
314 	void (*read_bulk_callback)(struct urb *urb);
315 	void (*write_bulk_callback)(struct urb *urb);
316 	/* Called by the generic read bulk callback */
317 	void (*process_read_urb)(struct urb *urb);
318 	/* Called by the generic write implementation */
319 	int (*prepare_write_buffer)(struct usb_serial_port *port,
320 						void *dest, size_t size);
321 };
322 #define to_usb_serial_driver(d) \
323 	container_of(d, struct usb_serial_driver, driver)
324 
325 extern int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
326 		const char *name, const struct usb_device_id *id_table);
327 extern void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
328 extern void usb_serial_port_softint(struct usb_serial_port *port);
329 
330 extern int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
331 extern int usb_serial_resume(struct usb_interface *intf);
332 
333 /* USB Serial console functions */
334 #ifdef CONFIG_USB_SERIAL_CONSOLE
335 extern void usb_serial_console_init(int minor);
336 extern void usb_serial_console_exit(void);
337 extern void usb_serial_console_disconnect(struct usb_serial *serial);
338 #else
339 static inline void usb_serial_console_init(int minor) { }
340 static inline void usb_serial_console_exit(void) { }
341 static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
342 #endif
343 
344 /* Functions needed by other parts of the usbserial core */
345 extern struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
346 extern void usb_serial_put(struct usb_serial *serial);
347 extern int usb_serial_generic_open(struct tty_struct *tty,
348 	struct usb_serial_port *port);
349 extern int usb_serial_generic_write_start(struct usb_serial_port *port,
350 							gfp_t mem_flags);
351 extern int usb_serial_generic_write(struct tty_struct *tty,
352 	struct usb_serial_port *port, const unsigned char *buf, int count);
353 extern void usb_serial_generic_close(struct usb_serial_port *port);
354 extern int usb_serial_generic_resume(struct usb_serial *serial);
355 extern int usb_serial_generic_write_room(struct tty_struct *tty);
356 extern int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
357 extern void usb_serial_generic_wait_until_sent(struct tty_struct *tty,
358 								long timeout);
359 extern void usb_serial_generic_read_bulk_callback(struct urb *urb);
360 extern void usb_serial_generic_write_bulk_callback(struct urb *urb);
361 extern void usb_serial_generic_throttle(struct tty_struct *tty);
362 extern void usb_serial_generic_unthrottle(struct tty_struct *tty);
363 extern int usb_serial_generic_tiocmiwait(struct tty_struct *tty,
364 							unsigned long arg);
365 extern int usb_serial_generic_get_icount(struct tty_struct *tty,
366 					struct serial_icounter_struct *icount);
367 extern int usb_serial_generic_register(void);
368 extern void usb_serial_generic_deregister(void);
369 extern int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
370 						 gfp_t mem_flags);
371 extern void usb_serial_generic_process_read_urb(struct urb *urb);
372 extern int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
373 						void *dest, size_t size);
374 extern int usb_serial_handle_sysrq_char(struct usb_serial_port *port,
375 					unsigned int ch);
376 extern int usb_serial_handle_break(struct usb_serial_port *port);
377 extern void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
378 					 struct tty_struct *tty,
379 					 unsigned int status);
380 
381 
382 extern int usb_serial_bus_register(struct usb_serial_driver *device);
383 extern void usb_serial_bus_deregister(struct usb_serial_driver *device);
384 
385 extern struct bus_type usb_serial_bus_type;
386 extern struct tty_driver *usb_serial_tty_driver;
387 
388 static inline void usb_serial_debug_data(struct device *dev,
389 					 const char *function, int size,
390 					 const unsigned char *data)
391 {
392 	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
393 		function, size, size, data);
394 }
395 
396 /*
397  * Macro for reporting errors in write path to avoid inifinite loop
398  * when port is used as a console.
399  */
400 #define dev_err_console(usport, fmt, ...)				\
401 do {									\
402 	static bool __print_once;					\
403 	struct usb_serial_port *__port = (usport);			\
404 									\
405 	if (!__port->port.console || !__print_once) {			\
406 		__print_once = true;					\
407 		dev_err(&__port->dev, fmt, ##__VA_ARGS__);		\
408 	}								\
409 } while (0)
410 
411 /*
412  * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
413  * @__serial_drivers: list of usb_serial drivers to register
414  * @__ids: all device ids that @__serial_drivers bind to
415  *
416  * Helper macro for USB serial drivers which do not do anything special
417  * in module init/exit. This eliminates a lot of boilerplate. Each
418  * module may only use this macro once, and calling it replaces
419  * module_init() and module_exit()
420  *
421  */
422 #define usb_serial_module_driver(__name, __serial_drivers, __ids)	\
423 static int __init usb_serial_module_init(void)				\
424 {									\
425 	return usb_serial_register_drivers(__serial_drivers,		\
426 					   __name, __ids);		\
427 }									\
428 module_init(usb_serial_module_init);					\
429 static void __exit usb_serial_module_exit(void)				\
430 {									\
431 	usb_serial_deregister_drivers(__serial_drivers);		\
432 }									\
433 module_exit(usb_serial_module_exit);
434 
435 #define module_usb_serial_driver(__serial_drivers, __ids)		\
436 	usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
437 
438 #endif /* __LINUX_USB_SERIAL_H */
439 
440