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/kfifo.h>
21 
22 /* The maximum number of ports one device can grab at once */
23 #define MAX_NUM_PORTS		16
24 
25 /* USB serial flags */
26 #define USB_SERIAL_WRITE_BUSY	0
27 #define USB_SERIAL_THROTTLED	1
28 
29 /**
30  * usb_serial_port: structure for the specific ports of a device.
31  * @serial: pointer back to the struct usb_serial owner of this port.
32  * @port: pointer to the corresponding tty_port for this port.
33  * @lock: spinlock to grab when updating portions of this structure.
34  * @minor: the minor number of the port
35  * @port_number: the struct usb_serial port number of this port (starts at 0)
36  * @interrupt_in_buffer: pointer to the interrupt in buffer for this port.
37  * @interrupt_in_urb: pointer to the interrupt in struct urb for this port.
38  * @interrupt_in_endpointAddress: endpoint address for the interrupt in pipe
39  *	for this port.
40  * @interrupt_out_buffer: pointer to the interrupt out buffer for this port.
41  * @interrupt_out_size: the size of the interrupt_out_buffer, in bytes.
42  * @interrupt_out_urb: pointer to the interrupt out struct urb for this port.
43  * @interrupt_out_endpointAddress: endpoint address for the interrupt out pipe
44  *	for this port.
45  * @bulk_in_buffer: pointer to the bulk in buffer for this port.
46  * @bulk_in_size: the size of the bulk_in_buffer, in bytes.
47  * @read_urb: pointer to the bulk in struct urb for this port.
48  * @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this
49  *	port.
50  * @bulk_in_buffers: pointers to the bulk in buffers for this port
51  * @read_urbs: pointers to the bulk in urbs for this port
52  * @read_urbs_free: status bitmap the for bulk in urbs
53  * @bulk_out_buffer: pointer to the bulk out buffer for this port.
54  * @bulk_out_size: the size of the bulk_out_buffer, in bytes.
55  * @write_urb: pointer to the bulk out struct urb for this port.
56  * @write_fifo: kfifo used to buffer outgoing data
57  * @bulk_out_buffers: pointers to the bulk out buffers for this port
58  * @write_urbs: pointers to the bulk out urbs for this port
59  * @write_urbs_free: status bitmap the for bulk out urbs
60  * @icount: interrupt counters
61  * @tx_bytes: number of bytes currently in host stack queues
62  * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
63  *	port.
64  * @flags: usb serial port flags
65  * @work: work queue entry for the line discipline waking up.
66  * @dev: pointer to the serial device
67  *
68  * This structure is used by the usb-serial core and drivers for the specific
69  * ports of a device.
70  */
71 struct usb_serial_port {
72 	struct usb_serial	*serial;
73 	struct tty_port		port;
74 	spinlock_t		lock;
75 	u32			minor;
76 	u8			port_number;
77 
78 	unsigned char		*interrupt_in_buffer;
79 	struct urb		*interrupt_in_urb;
80 	__u8			interrupt_in_endpointAddress;
81 
82 	unsigned char		*interrupt_out_buffer;
83 	int			interrupt_out_size;
84 	struct urb		*interrupt_out_urb;
85 	__u8			interrupt_out_endpointAddress;
86 
87 	unsigned char		*bulk_in_buffer;
88 	int			bulk_in_size;
89 	struct urb		*read_urb;
90 	__u8			bulk_in_endpointAddress;
91 
92 	unsigned char		*bulk_in_buffers[2];
93 	struct urb		*read_urbs[2];
94 	unsigned long		read_urbs_free;
95 
96 	unsigned char		*bulk_out_buffer;
97 	int			bulk_out_size;
98 	struct urb		*write_urb;
99 	struct kfifo		write_fifo;
100 
101 	unsigned char		*bulk_out_buffers[2];
102 	struct urb		*write_urbs[2];
103 	unsigned long		write_urbs_free;
104 	__u8			bulk_out_endpointAddress;
105 
106 	struct async_icount	icount;
107 	int			tx_bytes;
108 
109 	unsigned long		flags;
110 	struct work_struct	work;
111 	unsigned long		sysrq; /* sysrq timeout */
112 	struct device		dev;
113 };
114 #define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)
115 
116 /* get and set the port private data pointer helper functions */
usb_get_serial_port_data(struct usb_serial_port * port)117 static inline void *usb_get_serial_port_data(struct usb_serial_port *port)
118 {
119 	return dev_get_drvdata(&port->dev);
120 }
121 
usb_set_serial_port_data(struct usb_serial_port * port,void * data)122 static inline void usb_set_serial_port_data(struct usb_serial_port *port,
123 					    void *data)
124 {
125 	dev_set_drvdata(&port->dev, data);
126 }
127 
128 /**
129  * usb_serial - structure used by the usb-serial core for a device
130  * @dev: pointer to the struct usb_device for this device
131  * @type: pointer to the struct usb_serial_driver for this device
132  * @interface: pointer to the struct usb_interface for this device
133  * @sibling: pointer to the struct usb_interface of any sibling interface
134  * @suspend_count: number of suspended (sibling) interfaces
135  * @num_ports: the number of ports this device has
136  * @num_interrupt_in: number of interrupt in endpoints we have
137  * @num_interrupt_out: number of interrupt out endpoints we have
138  * @num_bulk_in: number of bulk in endpoints we have
139  * @num_bulk_out: number of bulk out endpoints we have
140  * @port: array of struct usb_serial_port structures for the different ports.
141  * @private: place to put any driver specific information that is needed.  The
142  *	usb-serial driver is required to manage this data, the usb-serial core
143  *	will not touch this.  Use usb_get_serial_data() and
144  *	usb_set_serial_data() to access this.
145  */
146 struct usb_serial {
147 	struct usb_device		*dev;
148 	struct usb_serial_driver	*type;
149 	struct usb_interface		*interface;
150 	struct usb_interface		*sibling;
151 	unsigned int			suspend_count;
152 	unsigned char			disconnected: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 */
usb_get_serial_data(struct usb_serial * serial)169 static inline void *usb_get_serial_data(struct usb_serial *serial)
170 {
171 	return serial->private;
172 }
173 
usb_set_serial_data(struct usb_serial * serial,void * data)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
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 	void (*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 	unsigned int (*write_room)(struct tty_struct *tty);
280 	int  (*ioctl)(struct tty_struct *tty,
281 		      unsigned int cmd, unsigned long arg);
282 	void (*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 	unsigned 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 int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
320 		const char *name, const struct usb_device_id *id_table);
321 void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
322 void usb_serial_port_softint(struct usb_serial_port *port);
323 
324 int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
325 int usb_serial_resume(struct usb_interface *intf);
326 
327 /* USB Serial console functions */
328 #ifdef CONFIG_USB_SERIAL_CONSOLE
329 void usb_serial_console_init(int minor);
330 void usb_serial_console_exit(void);
331 void usb_serial_console_disconnect(struct usb_serial *serial);
332 #else
usb_serial_console_init(int minor)333 static inline void usb_serial_console_init(int minor) { }
usb_serial_console_exit(void)334 static inline void usb_serial_console_exit(void) { }
usb_serial_console_disconnect(struct usb_serial * serial)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 struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
340 void usb_serial_put(struct usb_serial *serial);
341 
342 int usb_serial_claim_interface(struct usb_serial *serial, struct usb_interface *intf);
343 
344 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port);
345 int usb_serial_generic_write_start(struct usb_serial_port *port, gfp_t mem_flags);
346 int usb_serial_generic_write(struct tty_struct *tty, struct usb_serial_port *port,
347 		const unsigned char *buf, int count);
348 void usb_serial_generic_close(struct usb_serial_port *port);
349 int usb_serial_generic_resume(struct usb_serial *serial);
350 unsigned int usb_serial_generic_write_room(struct tty_struct *tty);
351 unsigned int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
352 void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout);
353 void usb_serial_generic_read_bulk_callback(struct urb *urb);
354 void usb_serial_generic_write_bulk_callback(struct urb *urb);
355 void usb_serial_generic_throttle(struct tty_struct *tty);
356 void usb_serial_generic_unthrottle(struct tty_struct *tty);
357 int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg);
358 int usb_serial_generic_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount);
359 int usb_serial_generic_register(void);
360 void usb_serial_generic_deregister(void);
361 int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port, gfp_t mem_flags);
362 void usb_serial_generic_process_read_urb(struct urb *urb);
363 int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port, void *dest, size_t size);
364 
365 #if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
366 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch);
367 int usb_serial_handle_break(struct usb_serial_port *port);
368 #else
usb_serial_handle_sysrq_char(struct usb_serial_port * port,unsigned int ch)369 static inline int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
370 {
371 	return 0;
372 }
usb_serial_handle_break(struct usb_serial_port * port)373 static inline int usb_serial_handle_break(struct usb_serial_port *port)
374 {
375 	return 0;
376 }
377 #endif
378 
379 void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
380 		struct tty_struct *tty, unsigned int status);
381 
382 
383 int usb_serial_bus_register(struct usb_serial_driver *device);
384 void usb_serial_bus_deregister(struct usb_serial_driver *device);
385 
386 extern struct bus_type usb_serial_bus_type;
387 extern struct tty_driver *usb_serial_tty_driver;
388 
usb_serial_debug_data(struct device * dev,const char * function,int size,const unsigned char * data)389 static inline void usb_serial_debug_data(struct device *dev,
390 					 const char *function, int size,
391 					 const unsigned char *data)
392 {
393 	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
394 		function, size, size, data);
395 }
396 
397 /*
398  * Macro for reporting errors in write path to avoid infinite loop
399  * when port is used as a console.
400  */
401 #define dev_err_console(usport, fmt, ...)				\
402 do {									\
403 	static bool __print_once;					\
404 	struct usb_serial_port *__port = (usport);			\
405 									\
406 	if (!__port->port.console || !__print_once) {			\
407 		__print_once = true;					\
408 		dev_err(&__port->dev, fmt, ##__VA_ARGS__);		\
409 	}								\
410 } while (0)
411 
412 /*
413  * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
414  * @__serial_drivers: list of usb_serial drivers to register
415  * @__ids: all device ids that @__serial_drivers bind to
416  *
417  * Helper macro for USB serial drivers which do not do anything special
418  * in module init/exit. This eliminates a lot of boilerplate. Each
419  * module may only use this macro once, and calling it replaces
420  * module_init() and module_exit()
421  *
422  */
423 #define usb_serial_module_driver(__name, __serial_drivers, __ids)	\
424 static int __init usb_serial_module_init(void)				\
425 {									\
426 	return usb_serial_register_drivers(__serial_drivers,		\
427 					   __name, __ids);		\
428 }									\
429 module_init(usb_serial_module_init);					\
430 static void __exit usb_serial_module_exit(void)				\
431 {									\
432 	usb_serial_deregister_drivers(__serial_drivers);		\
433 }									\
434 module_exit(usb_serial_module_exit);
435 
436 #define module_usb_serial_driver(__serial_drivers, __ids)		\
437 	usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
438 
439 #endif /* __LINUX_USB_SERIAL_H */
440 
441