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 int usb_serial_register_drivers(struct usb_serial_driver *const serial_drivers[],
315 		const char *name, const struct usb_device_id *id_table);
316 void usb_serial_deregister_drivers(struct usb_serial_driver *const serial_drivers[]);
317 void usb_serial_port_softint(struct usb_serial_port *port);
318 
319 int usb_serial_suspend(struct usb_interface *intf, pm_message_t message);
320 int usb_serial_resume(struct usb_interface *intf);
321 
322 /* USB Serial console functions */
323 #ifdef CONFIG_USB_SERIAL_CONSOLE
324 void usb_serial_console_init(int minor);
325 void usb_serial_console_exit(void);
326 void usb_serial_console_disconnect(struct usb_serial *serial);
327 #else
usb_serial_console_init(int minor)328 static inline void usb_serial_console_init(int minor) { }
usb_serial_console_exit(void)329 static inline void usb_serial_console_exit(void) { }
usb_serial_console_disconnect(struct usb_serial * serial)330 static inline void usb_serial_console_disconnect(struct usb_serial *serial) {}
331 #endif
332 
333 /* Functions needed by other parts of the usbserial core */
334 struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
335 void usb_serial_put(struct usb_serial *serial);
336 
337 int usb_serial_claim_interface(struct usb_serial *serial, struct usb_interface *intf);
338 
339 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port);
340 int usb_serial_generic_write_start(struct usb_serial_port *port, gfp_t mem_flags);
341 int usb_serial_generic_write(struct tty_struct *tty, struct usb_serial_port *port,
342 		const unsigned char *buf, int count);
343 void usb_serial_generic_close(struct usb_serial_port *port);
344 int usb_serial_generic_resume(struct usb_serial *serial);
345 unsigned int usb_serial_generic_write_room(struct tty_struct *tty);
346 unsigned int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);
347 void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout);
348 void usb_serial_generic_read_bulk_callback(struct urb *urb);
349 void usb_serial_generic_write_bulk_callback(struct urb *urb);
350 void usb_serial_generic_throttle(struct tty_struct *tty);
351 void usb_serial_generic_unthrottle(struct tty_struct *tty);
352 int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg);
353 int usb_serial_generic_get_icount(struct tty_struct *tty, struct serial_icounter_struct *icount);
354 int usb_serial_generic_register(void);
355 void usb_serial_generic_deregister(void);
356 int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port, gfp_t mem_flags);
357 void usb_serial_generic_process_read_urb(struct urb *urb);
358 int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port, void *dest, size_t size);
359 
360 #if defined(CONFIG_USB_SERIAL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
361 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch);
362 int usb_serial_handle_break(struct usb_serial_port *port);
363 #else
usb_serial_handle_sysrq_char(struct usb_serial_port * port,unsigned int ch)364 static inline int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
365 {
366 	return 0;
367 }
usb_serial_handle_break(struct usb_serial_port * port)368 static inline int usb_serial_handle_break(struct usb_serial_port *port)
369 {
370 	return 0;
371 }
372 #endif
373 
374 void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
375 		struct tty_struct *tty, unsigned int status);
376 
377 
378 int usb_serial_bus_register(struct usb_serial_driver *device);
379 void usb_serial_bus_deregister(struct usb_serial_driver *device);
380 
381 extern const struct bus_type usb_serial_bus_type;
382 extern struct tty_driver *usb_serial_tty_driver;
383 
usb_serial_debug_data(struct device * dev,const char * function,int size,const unsigned char * data)384 static inline void usb_serial_debug_data(struct device *dev,
385 					 const char *function, int size,
386 					 const unsigned char *data)
387 {
388 	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
389 		function, size, size, data);
390 }
391 
392 /*
393  * Macro for reporting errors in write path to avoid infinite loop
394  * when port is used as a console.
395  */
396 #define dev_err_console(usport, fmt, ...)				\
397 do {									\
398 	static bool __print_once;					\
399 	struct usb_serial_port *__port = (usport);			\
400 									\
401 	if (!__port->port.console || !__print_once) {			\
402 		__print_once = true;					\
403 		dev_err(&__port->dev, fmt, ##__VA_ARGS__);		\
404 	}								\
405 } while (0)
406 
407 /*
408  * module_usb_serial_driver() - Helper macro for registering a USB Serial driver
409  * @__serial_drivers: list of usb_serial drivers to register
410  * @__ids: all device ids that @__serial_drivers bind to
411  *
412  * Helper macro for USB serial drivers which do not do anything special
413  * in module init/exit. This eliminates a lot of boilerplate. Each
414  * module may only use this macro once, and calling it replaces
415  * module_init() and module_exit()
416  *
417  */
418 #define usb_serial_module_driver(__name, __serial_drivers, __ids)	\
419 static int __init usb_serial_module_init(void)				\
420 {									\
421 	return usb_serial_register_drivers(__serial_drivers,		\
422 					   __name, __ids);		\
423 }									\
424 module_init(usb_serial_module_init);					\
425 static void __exit usb_serial_module_exit(void)				\
426 {									\
427 	usb_serial_deregister_drivers(__serial_drivers);		\
428 }									\
429 module_exit(usb_serial_module_exit);
430 
431 #define module_usb_serial_driver(__serial_drivers, __ids)		\
432 	usb_serial_module_driver(KBUILD_MODNAME, __serial_drivers, __ids)
433 
434 #endif /* __LINUX_USB_SERIAL_H */
435 
436