xref: /linux/drivers/usb/serial/cypress_m8.c (revision 9f9bfc80c67f35a275820da7e83a35dface08281)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * USB Cypress M8 driver
4  *
5  * 	Copyright (C) 2004
6  * 	    Lonnie Mendez (dignome@gmail.com)
7  *	Copyright (C) 2003,2004
8  *	    Neil Whelchel (koyama@firstlight.net)
9  *
10  * See Documentation/usb/usb-serial.rst for more information on using this
11  * driver
12  *
13  * See http://geocities.com/i0xox0i for information on this driver and the
14  * earthmate usb device.
15  */
16 
17 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation
18    for linux. */
19 /* Thanks to cypress for providing references for the hid reports. */
20 /* Thanks to Jiang Zhang for providing links and for general help. */
21 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
22 
23 
24 #include <linux/kernel.h>
25 #include <linux/errno.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_driver.h>
29 #include <linux/tty_flip.h>
30 #include <linux/module.h>
31 #include <linux/moduleparam.h>
32 #include <linux/spinlock.h>
33 #include <linux/usb.h>
34 #include <linux/usb/serial.h>
35 #include <linux/serial.h>
36 #include <linux/kfifo.h>
37 #include <linux/delay.h>
38 #include <linux/uaccess.h>
39 #include <linux/unaligned.h>
40 
41 #include "cypress_m8.h"
42 
43 
44 static bool stats;
45 static int interval;
46 static bool unstable_bauds;
47 
48 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
49 #define DRIVER_DESC "Cypress USB to Serial Driver"
50 
51 /* write buffer size defines */
52 #define CYPRESS_BUF_SIZE	1024
53 
54 static const struct usb_device_id id_table_earthmate[] = {
55 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
56 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
57 	{ }						/* Terminating entry */
58 };
59 
60 static const struct usb_device_id id_table_cyphidcomrs232[] = {
61 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
62 	{ USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
63 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
64 	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
65 	{ }						/* Terminating entry */
66 };
67 
68 static const struct usb_device_id id_table_nokiaca42v2[] = {
69 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
70 	{ }						/* Terminating entry */
71 };
72 
73 static const struct usb_device_id id_table_combined[] = {
74 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
75 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
76 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
77 	{ USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
78 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
79 	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
80 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
81 	{ }						/* Terminating entry */
82 };
83 
84 MODULE_DEVICE_TABLE(usb, id_table_combined);
85 
86 enum packet_format {
87 	packet_format_1,  /* b0:status, b1:payload count */
88 	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
89 };
90 
91 struct cypress_private {
92 	spinlock_t lock;		   /* private lock */
93 	int chiptype;			   /* identifier of device, for quirks/etc */
94 	int bytes_in;			   /* used for statistics */
95 	int bytes_out;			   /* used for statistics */
96 	int cmd_count;			   /* used for statistics */
97 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
98 	struct kfifo write_fifo;	   /* write fifo */
99 	int write_urb_in_use;		   /* write urb in use indicator */
100 	int write_urb_interval;            /* interval to use for write urb */
101 	int read_urb_interval;             /* interval to use for read urb */
102 	int comm_is_ok;                    /* true if communication is (still) ok */
103 	__u8 line_control;	   	   /* holds dtr / rts value */
104 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
105 	__u8 current_config;	   	   /* stores the current configuration byte */
106 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
107 	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
108 	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
109 	int baud_rate;			   /* stores current baud rate in
110 					      integer form */
111 	char prev_status;		   /* used for TIOCMIWAIT */
112 };
113 
114 /* function prototypes for the Cypress USB to serial device */
115 static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
116 static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
117 static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
118 static void cypress_port_remove(struct usb_serial_port *port);
119 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
120 static void cypress_close(struct usb_serial_port *port);
121 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
122 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
123 			const unsigned char *buf, int count);
124 static void cypress_send(struct usb_serial_port *port);
125 static unsigned int cypress_write_room(struct tty_struct *tty);
126 static void cypress_earthmate_init_termios(struct tty_struct *tty);
127 static void cypress_set_termios(struct tty_struct *tty,
128 				struct usb_serial_port *port,
129 				const struct ktermios *old_termios);
130 static int  cypress_tiocmget(struct tty_struct *tty);
131 static int  cypress_tiocmset(struct tty_struct *tty,
132 			unsigned int set, unsigned int clear);
133 static unsigned int cypress_chars_in_buffer(struct tty_struct *tty);
134 static void cypress_throttle(struct tty_struct *tty);
135 static void cypress_unthrottle(struct tty_struct *tty);
136 static void cypress_set_dead(struct usb_serial_port *port);
137 static void cypress_read_int_callback(struct urb *urb);
138 static void cypress_write_int_callback(struct urb *urb);
139 
140 static struct usb_serial_driver cypress_earthmate_device = {
141 	.driver = {
142 		.name =			"earthmate",
143 	},
144 	.description =			"DeLorme Earthmate USB",
145 	.id_table =			id_table_earthmate,
146 	.num_ports =			1,
147 	.port_probe =			cypress_earthmate_port_probe,
148 	.port_remove =			cypress_port_remove,
149 	.open =				cypress_open,
150 	.close =			cypress_close,
151 	.dtr_rts =			cypress_dtr_rts,
152 	.write =			cypress_write,
153 	.write_room =			cypress_write_room,
154 	.init_termios =			cypress_earthmate_init_termios,
155 	.set_termios =			cypress_set_termios,
156 	.tiocmget =			cypress_tiocmget,
157 	.tiocmset =			cypress_tiocmset,
158 	.tiocmiwait =			usb_serial_generic_tiocmiwait,
159 	.chars_in_buffer =		cypress_chars_in_buffer,
160 	.throttle =		 	cypress_throttle,
161 	.unthrottle =			cypress_unthrottle,
162 	.read_int_callback =		cypress_read_int_callback,
163 	.write_int_callback =		cypress_write_int_callback,
164 };
165 
166 static struct usb_serial_driver cypress_hidcom_device = {
167 	.driver = {
168 		.name =			"cyphidcom",
169 	},
170 	.description =			"HID->COM RS232 Adapter",
171 	.id_table =			id_table_cyphidcomrs232,
172 	.num_ports =			1,
173 	.port_probe =			cypress_hidcom_port_probe,
174 	.port_remove =			cypress_port_remove,
175 	.open =				cypress_open,
176 	.close =			cypress_close,
177 	.dtr_rts =			cypress_dtr_rts,
178 	.write =			cypress_write,
179 	.write_room =			cypress_write_room,
180 	.set_termios =			cypress_set_termios,
181 	.tiocmget =			cypress_tiocmget,
182 	.tiocmset =			cypress_tiocmset,
183 	.tiocmiwait =			usb_serial_generic_tiocmiwait,
184 	.chars_in_buffer =		cypress_chars_in_buffer,
185 	.throttle =			cypress_throttle,
186 	.unthrottle =			cypress_unthrottle,
187 	.read_int_callback =		cypress_read_int_callback,
188 	.write_int_callback =		cypress_write_int_callback,
189 };
190 
191 static struct usb_serial_driver cypress_ca42v2_device = {
192 	.driver = {
193 		.name =			"nokiaca42v2",
194 	},
195 	.description =			"Nokia CA-42 V2 Adapter",
196 	.id_table =			id_table_nokiaca42v2,
197 	.num_ports =			1,
198 	.port_probe =			cypress_ca42v2_port_probe,
199 	.port_remove =			cypress_port_remove,
200 	.open =				cypress_open,
201 	.close =			cypress_close,
202 	.dtr_rts =			cypress_dtr_rts,
203 	.write =			cypress_write,
204 	.write_room =			cypress_write_room,
205 	.set_termios =			cypress_set_termios,
206 	.tiocmget =			cypress_tiocmget,
207 	.tiocmset =			cypress_tiocmset,
208 	.tiocmiwait =			usb_serial_generic_tiocmiwait,
209 	.chars_in_buffer =		cypress_chars_in_buffer,
210 	.throttle =			cypress_throttle,
211 	.unthrottle =			cypress_unthrottle,
212 	.read_int_callback =		cypress_read_int_callback,
213 	.write_int_callback =		cypress_write_int_callback,
214 };
215 
216 static struct usb_serial_driver * const serial_drivers[] = {
217 	&cypress_earthmate_device, &cypress_hidcom_device,
218 	&cypress_ca42v2_device, NULL
219 };
220 
221 /*****************************************************************************
222  * Cypress serial helper functions
223  *****************************************************************************/
224 
225 /* FRWD Dongle hidcom needs to skip reset and speed checks */
226 static inline bool is_frwd(struct usb_device *dev)
227 {
228 	return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
229 		(le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
230 }
231 
232 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
233 {
234 	struct cypress_private *priv;
235 	priv = usb_get_serial_port_data(port);
236 
237 	if (unstable_bauds)
238 		return new_rate;
239 
240 	/* FRWD Dongle uses 115200 bps */
241 	if (is_frwd(port->serial->dev))
242 		return new_rate;
243 
244 	/*
245 	 * The general purpose firmware for the Cypress M8 allows for
246 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
247 	 * chose to use the general purpose firmware or not), if you
248 	 * need to modify this speed setting for your own project
249 	 * please add your own chiptype and modify the code likewise.
250 	 * The Cypress HID->COM device will work successfully up to
251 	 * 115200bps (but the actual throughput is around 3kBps).
252 	 */
253 	if (port->serial->dev->speed == USB_SPEED_LOW) {
254 		/*
255 		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
256 		 * Cypress app note that describes this mechanism
257 		 * states that the low-speed part can't handle more
258 		 * than 800 bytes/sec, in which case 4800 baud is the
259 		 * safest speed for a part like that.
260 		 */
261 		if (new_rate > 4800) {
262 			dev_dbg(&port->dev,
263 				"%s - failed setting baud rate, device incapable speed %d\n",
264 				__func__, new_rate);
265 			return -1;
266 		}
267 	}
268 	switch (priv->chiptype) {
269 	case CT_EARTHMATE:
270 		if (new_rate <= 600) {
271 			/* 300 and 600 baud rates are supported under
272 			 * the generic firmware, but are not used with
273 			 * NMEA and SiRF protocols */
274 			dev_dbg(&port->dev,
275 				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS\n",
276 				__func__, new_rate);
277 			return -1;
278 		}
279 		break;
280 	default:
281 		break;
282 	}
283 	return new_rate;
284 }
285 
286 
287 /* This function can either set or retrieve the current serial line settings */
288 static int cypress_serial_control(struct tty_struct *tty,
289 	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
290 	int stop_bits, int parity_enable, int parity_type, int reset,
291 	int cypress_request_type)
292 {
293 	int new_baudrate = 0, retval = 0, tries = 0;
294 	struct cypress_private *priv;
295 	struct device *dev = &port->dev;
296 	u8 *feature_buffer;
297 	const unsigned int feature_len = 5;
298 	unsigned long flags;
299 
300 	priv = usb_get_serial_port_data(port);
301 
302 	if (!priv->comm_is_ok)
303 		return -ENODEV;
304 
305 	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
306 	if (!feature_buffer)
307 		return -ENOMEM;
308 
309 	switch (cypress_request_type) {
310 	case CYPRESS_SET_CONFIG:
311 		/* 0 means 'Hang up' so doesn't change the true bit rate */
312 		new_baudrate = priv->baud_rate;
313 		if (baud_rate && baud_rate != priv->baud_rate) {
314 			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
315 			retval = analyze_baud_rate(port, baud_rate);
316 			if (retval >= 0) {
317 				new_baudrate = retval;
318 				dev_dbg(dev, "%s - New baud rate set to %d\n",
319 					__func__, new_baudrate);
320 			}
321 		}
322 		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
323 			new_baudrate);
324 
325 		/* fill the feature_buffer with new configuration */
326 		put_unaligned_le32(new_baudrate, feature_buffer);
327 		feature_buffer[4] |= data_bits - 5;   /* assign data bits in 2 bit space ( max 3 ) */
328 		/* 1 bit gap */
329 		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
330 		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
331 		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
332 		/* 1 bit gap */
333 		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
334 
335 		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
336 		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
337 			feature_buffer[0], feature_buffer[1],
338 			feature_buffer[2], feature_buffer[3],
339 			feature_buffer[4]);
340 
341 		do {
342 			retval = usb_control_msg(port->serial->dev,
343 					usb_sndctrlpipe(port->serial->dev, 0),
344 					HID_REQ_SET_REPORT,
345 					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
346 					0x0300, 0, feature_buffer,
347 					feature_len, 500);
348 
349 			if (tries++ >= 3)
350 				break;
351 
352 		} while (retval != feature_len &&
353 			 retval != -ENODEV);
354 
355 		if (retval != feature_len) {
356 			dev_err(dev, "%s - failed sending serial line settings - %d\n",
357 				__func__, retval);
358 			cypress_set_dead(port);
359 		} else {
360 			spin_lock_irqsave(&priv->lock, flags);
361 			priv->baud_rate = new_baudrate;
362 			priv->current_config = feature_buffer[4];
363 			spin_unlock_irqrestore(&priv->lock, flags);
364 			/* If we asked for a speed change encode it */
365 			if (baud_rate)
366 				tty_encode_baud_rate(tty,
367 					new_baudrate, new_baudrate);
368 		}
369 	break;
370 	case CYPRESS_GET_CONFIG:
371 		if (priv->get_cfg_unsafe) {
372 			/* Not implemented for this device,
373 			   and if we try to do it we're likely
374 			   to crash the hardware. */
375 			retval = -ENOTTY;
376 			goto out;
377 		}
378 		dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
379 		do {
380 			retval = usb_control_msg(port->serial->dev,
381 					usb_rcvctrlpipe(port->serial->dev, 0),
382 					HID_REQ_GET_REPORT,
383 					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
384 					0x0300, 0, feature_buffer,
385 					feature_len, 500);
386 
387 			if (tries++ >= 3)
388 				break;
389 		} while (retval != feature_len
390 						&& retval != -ENODEV);
391 
392 		if (retval != feature_len) {
393 			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
394 				__func__, retval);
395 			cypress_set_dead(port);
396 			goto out;
397 		} else {
398 			spin_lock_irqsave(&priv->lock, flags);
399 			/* store the config in one byte, and later
400 			   use bit masks to check values */
401 			priv->current_config = feature_buffer[4];
402 			priv->baud_rate = get_unaligned_le32(feature_buffer);
403 			spin_unlock_irqrestore(&priv->lock, flags);
404 		}
405 	}
406 	spin_lock_irqsave(&priv->lock, flags);
407 	++priv->cmd_count;
408 	spin_unlock_irqrestore(&priv->lock, flags);
409 out:
410 	kfree(feature_buffer);
411 	return retval;
412 } /* cypress_serial_control */
413 
414 
415 static void cypress_set_dead(struct usb_serial_port *port)
416 {
417 	struct cypress_private *priv = usb_get_serial_port_data(port);
418 	unsigned long flags;
419 
420 	spin_lock_irqsave(&priv->lock, flags);
421 	if (!priv->comm_is_ok) {
422 		spin_unlock_irqrestore(&priv->lock, flags);
423 		return;
424 	}
425 	priv->comm_is_ok = 0;
426 	spin_unlock_irqrestore(&priv->lock, flags);
427 
428 	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
429 		"interval might be too short\n", port->port_number);
430 }
431 
432 
433 /*****************************************************************************
434  * Cypress serial driver functions
435  *****************************************************************************/
436 
437 
438 static int cypress_generic_port_probe(struct usb_serial_port *port)
439 {
440 	struct usb_serial *serial = port->serial;
441 	struct cypress_private *priv;
442 
443 	if (!port->interrupt_out_urb || !port->interrupt_in_urb) {
444 		dev_err(&port->dev, "required endpoint is missing\n");
445 		return -ENODEV;
446 	}
447 
448 	/*
449 	 * The buffer must be large enough for the one or two-byte header (and
450 	 * following data), but assume anything smaller than eight bytes is
451 	 * broken.
452 	 */
453 	if (port->interrupt_out_size < 8)
454 		return -EINVAL;
455 
456 	priv = kzalloc_obj(struct cypress_private);
457 	if (!priv)
458 		return -ENOMEM;
459 
460 	priv->comm_is_ok = !0;
461 	spin_lock_init(&priv->lock);
462 	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
463 		kfree(priv);
464 		return -ENOMEM;
465 	}
466 
467 	/* Skip reset for FRWD device. It is a workaound:
468 	   device hangs if it receives SET_CONFIGURE in Configured
469 	   state. */
470 	if (!is_frwd(serial->dev))
471 		usb_reset_configuration(serial->dev);
472 
473 	priv->cmd_ctrl = 0;
474 	priv->line_control = 0;
475 	priv->rx_flags = 0;
476 	/* Default packet format setting is determined by packet size.
477 	   Anything with a size larger then 9 must have a separate
478 	   count field since the 3 bit count field is otherwise too
479 	   small.  Otherwise we can use the slightly more compact
480 	   format.  This is in accordance with the cypress_m8 serial
481 	   converter app note. */
482 	if (port->interrupt_out_size > 9)
483 		priv->pkt_fmt = packet_format_1;
484 	else
485 		priv->pkt_fmt = packet_format_2;
486 
487 	if (interval > 0) {
488 		priv->write_urb_interval = interval;
489 		priv->read_urb_interval = interval;
490 		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
491 			__func__, interval);
492 	} else {
493 		priv->write_urb_interval = port->interrupt_out_urb->interval;
494 		priv->read_urb_interval = port->interrupt_in_urb->interval;
495 		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
496 			__func__, priv->read_urb_interval,
497 			priv->write_urb_interval);
498 	}
499 	usb_set_serial_port_data(port, priv);
500 
501 	port->port.drain_delay = 256;
502 
503 	return 0;
504 }
505 
506 
507 static int cypress_earthmate_port_probe(struct usb_serial_port *port)
508 {
509 	struct usb_serial *serial = port->serial;
510 	struct cypress_private *priv;
511 	int ret;
512 
513 	ret = cypress_generic_port_probe(port);
514 	if (ret) {
515 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
516 		return ret;
517 	}
518 
519 	priv = usb_get_serial_port_data(port);
520 	priv->chiptype = CT_EARTHMATE;
521 	/* All Earthmate devices use the separated-count packet
522 	   format!  Idiotic. */
523 	priv->pkt_fmt = packet_format_1;
524 	if (serial->dev->descriptor.idProduct !=
525 				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
526 		/* The old original USB Earthmate seemed able to
527 		   handle GET_CONFIG requests; everything they've
528 		   produced since that time crashes if this command is
529 		   attempted :-( */
530 		dev_dbg(&port->dev,
531 			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
532 			__func__);
533 		priv->get_cfg_unsafe = !0;
534 	}
535 
536 	return 0;
537 }
538 
539 static int cypress_hidcom_port_probe(struct usb_serial_port *port)
540 {
541 	struct cypress_private *priv;
542 	int ret;
543 
544 	ret = cypress_generic_port_probe(port);
545 	if (ret) {
546 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
547 		return ret;
548 	}
549 
550 	priv = usb_get_serial_port_data(port);
551 	priv->chiptype = CT_CYPHIDCOM;
552 
553 	return 0;
554 }
555 
556 static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
557 {
558 	struct cypress_private *priv;
559 	int ret;
560 
561 	ret = cypress_generic_port_probe(port);
562 	if (ret) {
563 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
564 		return ret;
565 	}
566 
567 	priv = usb_get_serial_port_data(port);
568 	priv->chiptype = CT_CA42V2;
569 
570 	return 0;
571 }
572 
573 static void cypress_port_remove(struct usb_serial_port *port)
574 {
575 	struct cypress_private *priv;
576 
577 	priv = usb_get_serial_port_data(port);
578 
579 	kfifo_free(&priv->write_fifo);
580 	kfree(priv);
581 }
582 
583 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
584 {
585 	struct cypress_private *priv = usb_get_serial_port_data(port);
586 	struct usb_serial *serial = port->serial;
587 	unsigned long flags;
588 	int result = 0;
589 
590 	if (!priv->comm_is_ok)
591 		return -EIO;
592 
593 	/* clear halts before open */
594 	usb_clear_halt(serial->dev, 0x81);
595 	usb_clear_halt(serial->dev, 0x02);
596 
597 	spin_lock_irqsave(&priv->lock, flags);
598 	/* reset read/write statistics */
599 	priv->bytes_in = 0;
600 	priv->bytes_out = 0;
601 	priv->cmd_count = 0;
602 	priv->rx_flags = 0;
603 	spin_unlock_irqrestore(&priv->lock, flags);
604 
605 	/* Set termios */
606 	cypress_send(port);
607 
608 	if (tty)
609 		cypress_set_termios(tty, port, NULL);
610 
611 	/* setup the port and start reading from the device */
612 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
613 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
614 		port->interrupt_in_urb->transfer_buffer,
615 		port->interrupt_in_urb->transfer_buffer_length,
616 		cypress_read_int_callback, port, priv->read_urb_interval);
617 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
618 
619 	if (result) {
620 		dev_err(&port->dev,
621 			"%s - failed submitting read urb, error %d\n",
622 							__func__, result);
623 		cypress_set_dead(port);
624 	}
625 
626 	return result;
627 } /* cypress_open */
628 
629 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
630 {
631 	struct cypress_private *priv = usb_get_serial_port_data(port);
632 	/* drop dtr and rts */
633 	spin_lock_irq(&priv->lock);
634 	if (on == 0)
635 		priv->line_control = 0;
636 	else
637 		priv->line_control = CONTROL_DTR | CONTROL_RTS;
638 	priv->cmd_ctrl = 1;
639 	spin_unlock_irq(&priv->lock);
640 	cypress_write(NULL, port, NULL, 0);
641 }
642 
643 static void cypress_close(struct usb_serial_port *port)
644 {
645 	struct cypress_private *priv = usb_get_serial_port_data(port);
646 	unsigned long flags;
647 
648 	spin_lock_irqsave(&priv->lock, flags);
649 	kfifo_reset_out(&priv->write_fifo);
650 	spin_unlock_irqrestore(&priv->lock, flags);
651 
652 	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
653 	usb_kill_urb(port->interrupt_in_urb);
654 	usb_kill_urb(port->interrupt_out_urb);
655 
656 	if (stats)
657 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
658 			priv->bytes_in, priv->bytes_out, priv->cmd_count);
659 } /* cypress_close */
660 
661 
662 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
663 					const unsigned char *buf, int count)
664 {
665 	struct cypress_private *priv = usb_get_serial_port_data(port);
666 
667 	dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
668 
669 	/* line control commands, which need to be executed immediately,
670 	   are not put into the buffer for obvious reasons.
671 	 */
672 	if (priv->cmd_ctrl) {
673 		count = 0;
674 		goto finish;
675 	}
676 
677 	if (!count)
678 		return count;
679 
680 	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
681 
682 finish:
683 	cypress_send(port);
684 
685 	return count;
686 } /* cypress_write */
687 
688 
689 static void cypress_send(struct usb_serial_port *port)
690 {
691 	int count = 0, result, offset, actual_size;
692 	struct cypress_private *priv = usb_get_serial_port_data(port);
693 	struct device *dev = &port->dev;
694 	unsigned long flags;
695 
696 	if (!priv->comm_is_ok)
697 		return;
698 
699 	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
700 		port->interrupt_out_size);
701 
702 	spin_lock_irqsave(&priv->lock, flags);
703 	if (priv->write_urb_in_use) {
704 		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
705 		spin_unlock_irqrestore(&priv->lock, flags);
706 		return;
707 	}
708 	spin_unlock_irqrestore(&priv->lock, flags);
709 
710 	/* clear buffer */
711 	memset(port->interrupt_out_urb->transfer_buffer, 0,
712 						port->interrupt_out_size);
713 
714 	spin_lock_irqsave(&priv->lock, flags);
715 	switch (priv->pkt_fmt) {
716 	default:
717 	case packet_format_1:
718 		/* this is for the CY7C64013... */
719 		offset = 2;
720 		port->interrupt_out_buffer[0] = priv->line_control;
721 		break;
722 	case packet_format_2:
723 		/* this is for the CY7C63743... */
724 		offset = 1;
725 		port->interrupt_out_buffer[0] = priv->line_control;
726 		break;
727 	}
728 
729 	if (priv->line_control & CONTROL_RESET)
730 		priv->line_control &= ~CONTROL_RESET;
731 
732 	if (priv->cmd_ctrl) {
733 		priv->cmd_count++;
734 		dev_dbg(dev, "%s - line control command being issued\n", __func__);
735 		spin_unlock_irqrestore(&priv->lock, flags);
736 		goto send;
737 	} else
738 		spin_unlock_irqrestore(&priv->lock, flags);
739 
740 	count = kfifo_out_locked(&priv->write_fifo,
741 					&port->interrupt_out_buffer[offset],
742 					port->interrupt_out_size - offset,
743 					&priv->lock);
744 	if (count == 0)
745 		return;
746 
747 	switch (priv->pkt_fmt) {
748 	default:
749 	case packet_format_1:
750 		port->interrupt_out_buffer[1] = count;
751 		break;
752 	case packet_format_2:
753 		port->interrupt_out_buffer[0] |= count;
754 	}
755 
756 	dev_dbg(dev, "%s - count is %d\n", __func__, count);
757 
758 send:
759 	spin_lock_irqsave(&priv->lock, flags);
760 	priv->write_urb_in_use = 1;
761 	spin_unlock_irqrestore(&priv->lock, flags);
762 
763 	if (priv->cmd_ctrl)
764 		actual_size = 1;
765 	else
766 		actual_size = count +
767 			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
768 
769 	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
770 			      port->interrupt_out_urb->transfer_buffer);
771 
772 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
773 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
774 		port->interrupt_out_buffer, actual_size,
775 		cypress_write_int_callback, port, priv->write_urb_interval);
776 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
777 	if (result) {
778 		dev_err_console(port,
779 				"%s - failed submitting write urb, error %d\n",
780 							__func__, result);
781 		priv->write_urb_in_use = 0;
782 		cypress_set_dead(port);
783 	}
784 
785 	spin_lock_irqsave(&priv->lock, flags);
786 	if (priv->cmd_ctrl)
787 		priv->cmd_ctrl = 0;
788 
789 	/* do not count the line control and size bytes */
790 	priv->bytes_out += count;
791 	spin_unlock_irqrestore(&priv->lock, flags);
792 
793 	usb_serial_port_softint(port);
794 } /* cypress_send */
795 
796 
797 /* returns how much space is available in the soft buffer */
798 static unsigned int cypress_write_room(struct tty_struct *tty)
799 {
800 	struct usb_serial_port *port = tty->driver_data;
801 	struct cypress_private *priv = usb_get_serial_port_data(port);
802 	unsigned int room;
803 	unsigned long flags;
804 
805 	spin_lock_irqsave(&priv->lock, flags);
806 	room = kfifo_avail(&priv->write_fifo);
807 	spin_unlock_irqrestore(&priv->lock, flags);
808 
809 	dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
810 	return room;
811 }
812 
813 
814 static int cypress_tiocmget(struct tty_struct *tty)
815 {
816 	struct usb_serial_port *port = tty->driver_data;
817 	struct cypress_private *priv = usb_get_serial_port_data(port);
818 	__u8 status, control;
819 	unsigned int result = 0;
820 	unsigned long flags;
821 
822 	spin_lock_irqsave(&priv->lock, flags);
823 	control = priv->line_control;
824 	status = priv->current_status;
825 	spin_unlock_irqrestore(&priv->lock, flags);
826 
827 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
828 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
829 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
830 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
831 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
832 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
833 
834 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
835 
836 	return result;
837 }
838 
839 
840 static int cypress_tiocmset(struct tty_struct *tty,
841 			       unsigned int set, unsigned int clear)
842 {
843 	struct usb_serial_port *port = tty->driver_data;
844 	struct cypress_private *priv = usb_get_serial_port_data(port);
845 	unsigned long flags;
846 
847 	spin_lock_irqsave(&priv->lock, flags);
848 	if (set & TIOCM_RTS)
849 		priv->line_control |= CONTROL_RTS;
850 	if (set & TIOCM_DTR)
851 		priv->line_control |= CONTROL_DTR;
852 	if (clear & TIOCM_RTS)
853 		priv->line_control &= ~CONTROL_RTS;
854 	if (clear & TIOCM_DTR)
855 		priv->line_control &= ~CONTROL_DTR;
856 	priv->cmd_ctrl = 1;
857 	spin_unlock_irqrestore(&priv->lock, flags);
858 
859 	return cypress_write(tty, port, NULL, 0);
860 }
861 
862 static void cypress_earthmate_init_termios(struct tty_struct *tty)
863 {
864 	tty_encode_baud_rate(tty, 4800, 4800);
865 }
866 
867 static void cypress_set_termios(struct tty_struct *tty,
868 				struct usb_serial_port *port,
869 				const struct ktermios *old_termios)
870 {
871 	struct cypress_private *priv = usb_get_serial_port_data(port);
872 	struct device *dev = &port->dev;
873 	int data_bits, stop_bits, parity_type, parity_enable;
874 	unsigned int cflag;
875 	unsigned long flags;
876 	__u8 oldlines;
877 	int linechange = 0;
878 
879 	/* Unsupported features need clearing */
880 	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
881 
882 	cflag = tty->termios.c_cflag;
883 
884 	/* set number of data bits, parity, stop bits */
885 	/* when parity is disabled the parity type bit is ignored */
886 
887 	/* 1 means 2 stop bits, 0 means 1 stop bit */
888 	stop_bits = cflag & CSTOPB ? 1 : 0;
889 
890 	if (cflag & PARENB) {
891 		parity_enable = 1;
892 		/* 1 means odd parity, 0 means even parity */
893 		parity_type = cflag & PARODD ? 1 : 0;
894 	} else
895 		parity_enable = parity_type = 0;
896 
897 	data_bits = tty_get_char_size(cflag);
898 
899 	spin_lock_irqsave(&priv->lock, flags);
900 	oldlines = priv->line_control;
901 	if ((cflag & CBAUD) == B0) {
902 		/* drop dtr and rts */
903 		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
904 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
905 	} else
906 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
907 	spin_unlock_irqrestore(&priv->lock, flags);
908 
909 	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
910 		__func__, stop_bits, parity_enable, parity_type, data_bits);
911 
912 	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
913 			data_bits, stop_bits,
914 			parity_enable, parity_type,
915 			0, CYPRESS_SET_CONFIG);
916 
917 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
918 	 * filled into the private structure this should confirm that all is
919 	 * working if it returns what we just set */
920 	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
921 
922 	/* Here we can define custom tty settings for devices; the main tty
923 	 * termios flag base comes from empeg.c */
924 
925 	spin_lock_irqsave(&priv->lock, flags);
926 	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
927 		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
928 		/* define custom termios settings for NMEA protocol */
929 
930 		tty->termios.c_iflag /* input modes - */
931 			&= ~(IGNBRK  /* disable ignore break */
932 			| BRKINT     /* disable break causes interrupt */
933 			| PARMRK     /* disable mark parity errors */
934 			| ISTRIP     /* disable clear high bit of input char */
935 			| INLCR      /* disable translate NL to CR */
936 			| IGNCR      /* disable ignore CR */
937 			| ICRNL      /* disable translate CR to NL */
938 			| IXON);     /* disable enable XON/XOFF flow control */
939 
940 		tty->termios.c_oflag /* output modes */
941 			&= ~OPOST;    /* disable postprocess output char */
942 
943 		tty->termios.c_lflag /* line discipline modes */
944 			&= ~(ECHO     /* disable echo input characters */
945 			| ECHONL      /* disable echo new line */
946 			| ICANON      /* disable erase, kill, werase, and rprnt
947 					 special characters */
948 			| ISIG        /* disable interrupt, quit, and suspend
949 					 special characters */
950 			| IEXTEN);    /* disable non-POSIX special characters */
951 	} /* CT_CYPHIDCOM: Application should handle this for device */
952 
953 	linechange = (priv->line_control != oldlines);
954 	spin_unlock_irqrestore(&priv->lock, flags);
955 
956 	/* if necessary, set lines */
957 	if (linechange) {
958 		priv->cmd_ctrl = 1;
959 		cypress_write(tty, port, NULL, 0);
960 	}
961 } /* cypress_set_termios */
962 
963 
964 /* returns amount of data still left in soft buffer */
965 static unsigned int cypress_chars_in_buffer(struct tty_struct *tty)
966 {
967 	struct usb_serial_port *port = tty->driver_data;
968 	struct cypress_private *priv = usb_get_serial_port_data(port);
969 	unsigned int chars;
970 	unsigned long flags;
971 
972 	spin_lock_irqsave(&priv->lock, flags);
973 	chars = kfifo_len(&priv->write_fifo);
974 	spin_unlock_irqrestore(&priv->lock, flags);
975 
976 	dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
977 	return chars;
978 }
979 
980 
981 static void cypress_throttle(struct tty_struct *tty)
982 {
983 	struct usb_serial_port *port = tty->driver_data;
984 	struct cypress_private *priv = usb_get_serial_port_data(port);
985 
986 	spin_lock_irq(&priv->lock);
987 	priv->rx_flags = THROTTLED;
988 	spin_unlock_irq(&priv->lock);
989 }
990 
991 
992 static void cypress_unthrottle(struct tty_struct *tty)
993 {
994 	struct usb_serial_port *port = tty->driver_data;
995 	struct cypress_private *priv = usb_get_serial_port_data(port);
996 	int actually_throttled, result;
997 
998 	spin_lock_irq(&priv->lock);
999 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1000 	priv->rx_flags = 0;
1001 	spin_unlock_irq(&priv->lock);
1002 
1003 	if (!priv->comm_is_ok)
1004 		return;
1005 
1006 	if (actually_throttled) {
1007 		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1008 		if (result) {
1009 			dev_err(&port->dev, "%s - failed submitting read urb, "
1010 					"error %d\n", __func__, result);
1011 			cypress_set_dead(port);
1012 		}
1013 	}
1014 }
1015 
1016 
1017 static void cypress_read_int_callback(struct urb *urb)
1018 {
1019 	struct usb_serial_port *port = urb->context;
1020 	struct cypress_private *priv = usb_get_serial_port_data(port);
1021 	struct device *dev = &urb->dev->dev;
1022 	struct tty_struct *tty;
1023 	unsigned char *data = urb->transfer_buffer;
1024 	unsigned long flags;
1025 	char tty_flag = TTY_NORMAL;
1026 	int bytes = 0;
1027 	int result;
1028 	int status = urb->status;
1029 	int i;
1030 
1031 	switch (status) {
1032 	case 0: /* success */
1033 		break;
1034 	case -ECONNRESET:
1035 	case -ENOENT:
1036 	case -ESHUTDOWN:
1037 		/* precursor to disconnect so just go away */
1038 		return;
1039 	case -EPIPE:
1040 		/* Can't call usb_clear_halt while in_interrupt */
1041 		fallthrough;
1042 	default:
1043 		/* something ugly is going on... */
1044 		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1045 			__func__, status);
1046 		cypress_set_dead(port);
1047 		return;
1048 	}
1049 
1050 	spin_lock_irqsave(&priv->lock, flags);
1051 	if (priv->rx_flags & THROTTLED) {
1052 		dev_dbg(dev, "%s - now throttling\n", __func__);
1053 		priv->rx_flags |= ACTUALLY_THROTTLED;
1054 		spin_unlock_irqrestore(&priv->lock, flags);
1055 		return;
1056 	}
1057 	spin_unlock_irqrestore(&priv->lock, flags);
1058 
1059 	tty = tty_port_tty_get(&port->port);
1060 	if (!tty) {
1061 		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1062 		return;
1063 	}
1064 
1065 	spin_lock_irqsave(&priv->lock, flags);
1066 	result = urb->actual_length;
1067 	i = 0;
1068 	switch (priv->pkt_fmt) {
1069 	default:
1070 	case packet_format_1:
1071 		/* This is for the CY7C64013... */
1072 		if (result < 2)
1073 			break;
1074 		priv->current_status = data[0] & 0xF8;
1075 		bytes = data[1] + 2;
1076 		i = 2;
1077 		break;
1078 	case packet_format_2:
1079 		/* This is for the CY7C63743... */
1080 		if (result < 1)
1081 			break;
1082 		priv->current_status = data[0] & 0xF8;
1083 		bytes = (data[0] & 0x07) + 1;
1084 		i = 1;
1085 		break;
1086 	}
1087 	spin_unlock_irqrestore(&priv->lock, flags);
1088 	if (i == 0) {
1089 		dev_dbg(dev, "%s - short packet received: %d bytes\n",
1090 			__func__, result);
1091 		goto continue_read;
1092 	}
1093 	if (result < bytes) {
1094 		dev_dbg(dev,
1095 			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1096 			__func__, result, bytes);
1097 		goto continue_read;
1098 	}
1099 
1100 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1101 
1102 	spin_lock_irqsave(&priv->lock, flags);
1103 	/* check to see if status has changed */
1104 	if (priv->current_status != priv->prev_status) {
1105 		u8 delta = priv->current_status ^ priv->prev_status;
1106 
1107 		if (delta & UART_MSR_MASK) {
1108 			if (delta & UART_CTS)
1109 				port->icount.cts++;
1110 			if (delta & UART_DSR)
1111 				port->icount.dsr++;
1112 			if (delta & UART_RI)
1113 				port->icount.rng++;
1114 			if (delta & UART_CD)
1115 				port->icount.dcd++;
1116 
1117 			wake_up_interruptible(&port->port.delta_msr_wait);
1118 		}
1119 
1120 		priv->prev_status = priv->current_status;
1121 	}
1122 	spin_unlock_irqrestore(&priv->lock, flags);
1123 
1124 	/* hangup, as defined in acm.c... this might be a bad place for it
1125 	 * though */
1126 	if (tty && !C_CLOCAL(tty) && !(priv->current_status & UART_CD)) {
1127 		dev_dbg(dev, "%s - calling hangup\n", __func__);
1128 		tty_hangup(tty);
1129 		goto continue_read;
1130 	}
1131 
1132 	/* There is one error bit... I'm assuming it is a parity error
1133 	 * indicator as the generic firmware will set this bit to 1 if a
1134 	 * parity error occurs.
1135 	 * I can not find reference to any other error events. */
1136 	spin_lock_irqsave(&priv->lock, flags);
1137 	if (priv->current_status & CYP_ERROR) {
1138 		spin_unlock_irqrestore(&priv->lock, flags);
1139 		tty_flag = TTY_PARITY;
1140 		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1141 	} else
1142 		spin_unlock_irqrestore(&priv->lock, flags);
1143 
1144 	/* process read if there is data other than line status */
1145 	if (bytes > i) {
1146 		tty_insert_flip_string_fixed_flag(&port->port, data + i,
1147 				tty_flag, bytes - i);
1148 		tty_flip_buffer_push(&port->port);
1149 	}
1150 
1151 	spin_lock_irqsave(&priv->lock, flags);
1152 	/* control and status byte(s) are also counted */
1153 	priv->bytes_in += bytes;
1154 	spin_unlock_irqrestore(&priv->lock, flags);
1155 
1156 continue_read:
1157 	tty_kref_put(tty);
1158 
1159 	/* Continue trying to always read */
1160 
1161 	if (priv->comm_is_ok) {
1162 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1163 				usb_rcvintpipe(port->serial->dev,
1164 					port->interrupt_in_endpointAddress),
1165 				port->interrupt_in_urb->transfer_buffer,
1166 				port->interrupt_in_urb->transfer_buffer_length,
1167 				cypress_read_int_callback, port,
1168 				priv->read_urb_interval);
1169 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1170 		if (result && result != -EPERM) {
1171 			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1172 				__func__, result);
1173 			cypress_set_dead(port);
1174 		}
1175 	}
1176 } /* cypress_read_int_callback */
1177 
1178 
1179 static void cypress_write_int_callback(struct urb *urb)
1180 {
1181 	struct usb_serial_port *port = urb->context;
1182 	struct cypress_private *priv = usb_get_serial_port_data(port);
1183 	struct device *dev = &urb->dev->dev;
1184 	int status = urb->status;
1185 
1186 	switch (status) {
1187 	case 0:
1188 		/* success */
1189 		break;
1190 	case -ECONNRESET:
1191 	case -ENOENT:
1192 	case -ESHUTDOWN:
1193 		/* this urb is terminated, clean up */
1194 		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1195 			__func__, status);
1196 		priv->write_urb_in_use = 0;
1197 		return;
1198 	case -EPIPE:
1199 		/* Cannot call usb_clear_halt while in_interrupt */
1200 		fallthrough;
1201 	default:
1202 		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1203 			__func__, status);
1204 		cypress_set_dead(port);
1205 		break;
1206 	}
1207 	priv->write_urb_in_use = 0;
1208 
1209 	/* send any buffered data */
1210 	cypress_send(port);
1211 }
1212 
1213 module_usb_serial_driver(serial_drivers, id_table_combined);
1214 
1215 MODULE_AUTHOR(DRIVER_AUTHOR);
1216 MODULE_DESCRIPTION(DRIVER_DESC);
1217 MODULE_LICENSE("GPL");
1218 
1219 module_param(stats, bool, 0644);
1220 MODULE_PARM_DESC(stats, "Enable statistics or not");
1221 module_param(interval, int, 0644);
1222 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1223 module_param(unstable_bauds, bool, 0644);
1224 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
1225