xref: /openbmc/linux/drivers/usb/serial/quatech2.c (revision 1e70d57e)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * usb-serial driver for Quatech USB 2 devices
4  *
5  * Copyright (C) 2012 Bill Pemberton (wfp5p@virginia.edu)
6  *
7  *  These devices all have only 1 bulk in and 1 bulk out that is shared
8  *  for all serial ports.
9  *
10  */
11 
12 #include <asm/unaligned.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/tty.h>
16 #include <linux/tty_driver.h>
17 #include <linux/tty_flip.h>
18 #include <linux/module.h>
19 #include <linux/serial.h>
20 #include <linux/usb.h>
21 #include <linux/usb/serial.h>
22 #include <linux/serial_reg.h>
23 #include <linux/uaccess.h>
24 
25 /* default urb timeout for usb operations */
26 #define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT
27 
28 #define QT_OPEN_CLOSE_CHANNEL       0xca
29 #define QT_SET_GET_DEVICE           0xc2
30 #define QT_SET_GET_REGISTER         0xc0
31 #define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
32 #define QT_SET_ATF                  0xcd
33 #define QT_TRANSFER_IN              0xc0
34 #define QT_HW_FLOW_CONTROL_MASK     0xc5
35 #define QT_SW_FLOW_CONTROL_MASK     0xc6
36 #define QT2_BREAK_CONTROL	    0xc8
37 #define QT2_GET_SET_UART            0xc1
38 #define QT2_FLUSH_DEVICE	    0xc4
39 #define QT2_GET_SET_QMCR            0xe1
40 #define QT2_QMCR_RS232              0x40
41 #define QT2_QMCR_RS422              0x10
42 
43 #define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
44 
45 #define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
46 
47 /* status bytes for the device */
48 #define QT2_CONTROL_BYTE    0x1b
49 #define QT2_LINE_STATUS     0x00  /* following 1 byte is line status */
50 #define QT2_MODEM_STATUS    0x01  /* following 1 byte is modem status */
51 #define QT2_XMIT_HOLD       0x02  /* following 2 bytes are ?? */
52 #define QT2_CHANGE_PORT     0x03  /* following 1 byte is port to change to */
53 #define QT2_REC_FLUSH       0x04  /* no following info */
54 #define QT2_XMIT_FLUSH      0x05  /* no following info */
55 #define QT2_CONTROL_ESCAPE  0xff  /* pass through previous 2 control bytes */
56 
57 #define  MAX_BAUD_RATE              921600
58 #define  DEFAULT_BAUD_RATE          9600
59 
60 #define QT2_READ_BUFFER_SIZE    512  /* size of read buffer */
61 #define QT2_WRITE_BUFFER_SIZE   512  /* size of write buffer */
62 #define QT2_WRITE_CONTROL_SIZE  5    /* control bytes used for a write */
63 
64 #define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver"
65 
66 #define	USB_VENDOR_ID_QUATECH	0x061d
67 #define QUATECH_SSU2_100	0xC120	/* RS232 single port */
68 #define QUATECH_DSU2_100	0xC140	/* RS232 dual port */
69 #define QUATECH_DSU2_400	0xC150	/* RS232/422/485 dual port */
70 #define QUATECH_QSU2_100	0xC160	/* RS232 four port */
71 #define QUATECH_QSU2_400	0xC170	/* RS232/422/485 four port */
72 #define QUATECH_ESU2_100	0xC1A0	/* RS232 eight port */
73 #define QUATECH_ESU2_400	0xC180	/* RS232/422/485 eight port */
74 
75 struct qt2_device_detail {
76 	int product_id;
77 	int num_ports;
78 };
79 
80 #define QT_DETAILS(prod, ports)	\
81 	.product_id = (prod),   \
82 	.num_ports = (ports)
83 
84 static const struct qt2_device_detail qt2_device_details[] = {
85 	{QT_DETAILS(QUATECH_SSU2_100, 1)},
86 	{QT_DETAILS(QUATECH_DSU2_400, 2)},
87 	{QT_DETAILS(QUATECH_DSU2_100, 2)},
88 	{QT_DETAILS(QUATECH_QSU2_400, 4)},
89 	{QT_DETAILS(QUATECH_QSU2_100, 4)},
90 	{QT_DETAILS(QUATECH_ESU2_400, 8)},
91 	{QT_DETAILS(QUATECH_ESU2_100, 8)},
92 	{QT_DETAILS(0, 0)}	/* Terminating entry */
93 };
94 
95 static const struct usb_device_id id_table[] = {
96 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)},
97 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)},
98 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)},
99 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)},
100 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)},
101 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)},
102 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)},
103 	{}			/* Terminating entry */
104 };
105 MODULE_DEVICE_TABLE(usb, id_table);
106 
107 struct qt2_serial_private {
108 	unsigned char current_port;  /* current port for incoming data */
109 
110 	struct urb	*read_urb;   /* shared among all ports */
111 	char		*read_buffer;
112 };
113 
114 struct qt2_port_private {
115 	u8   device_port;
116 
117 	spinlock_t urb_lock;
118 	bool       urb_in_use;
119 	struct urb *write_urb;
120 	char       *write_buffer;
121 
122 	spinlock_t  lock;
123 	u8          shadowLSR;
124 	u8          shadowMSR;
125 
126 	struct usb_serial_port *port;
127 };
128 
129 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
130 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
131 static void qt2_write_bulk_callback(struct urb *urb);
132 static void qt2_read_bulk_callback(struct urb *urb);
133 
134 static void qt2_release(struct usb_serial *serial)
135 {
136 	struct qt2_serial_private *serial_priv;
137 
138 	serial_priv = usb_get_serial_data(serial);
139 
140 	usb_kill_urb(serial_priv->read_urb);
141 	usb_free_urb(serial_priv->read_urb);
142 	kfree(serial_priv->read_buffer);
143 	kfree(serial_priv);
144 }
145 
146 static inline int calc_baud_divisor(int baudrate)
147 {
148 	int divisor, rem;
149 
150 	divisor = MAX_BAUD_RATE / baudrate;
151 	rem = MAX_BAUD_RATE % baudrate;
152 	/* Round to nearest divisor */
153 	if (((rem * 2) >= baudrate) && (baudrate != 110))
154 		divisor++;
155 
156 	return divisor;
157 }
158 
159 static inline int qt2_set_port_config(struct usb_device *dev,
160 				      unsigned char port_number,
161 				      u16 baudrate, u16 lcr)
162 {
163 	int divisor = calc_baud_divisor(baudrate);
164 	u16 index = ((u16) (lcr << 8) | (u16) (port_number));
165 
166 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
167 			       QT2_GET_SET_UART, 0x40,
168 			       divisor, index, NULL, 0, QT2_USB_TIMEOUT);
169 }
170 
171 static inline int qt2_control_msg(struct usb_device *dev,
172 				  u8 request, u16 data, u16 index)
173 {
174 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
175 			       request, 0x40, data, index,
176 			       NULL, 0, QT2_USB_TIMEOUT);
177 }
178 
179 static inline int qt2_setdevice(struct usb_device *dev, u8 *data)
180 {
181 	u16 x = ((u16) (data[1] << 8) | (u16) (data[0]));
182 
183 	return qt2_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
184 }
185 
186 
187 static inline int qt2_getregister(struct usb_device *dev,
188 				  u8 uart,
189 				  u8 reg,
190 				  u8 *data)
191 {
192 	int ret;
193 
194 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
195 			      QT_SET_GET_REGISTER, 0xc0, reg,
196 			      uart, data, sizeof(*data), QT2_USB_TIMEOUT);
197 	if (ret < (int)sizeof(*data)) {
198 		if (ret >= 0)
199 			ret = -EIO;
200 	}
201 
202 	return ret;
203 }
204 
205 static inline int qt2_setregister(struct usb_device *dev,
206 				  u8 uart, u8 reg, u16 data)
207 {
208 	u16 value = (data << 8) | reg;
209 
210 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
211 			       QT_SET_GET_REGISTER, 0x40, value, uart,
212 			       NULL, 0, QT2_USB_TIMEOUT);
213 }
214 
215 static inline int update_mctrl(struct qt2_port_private *port_priv,
216 			       unsigned int set, unsigned int clear)
217 {
218 	struct usb_serial_port *port = port_priv->port;
219 	struct usb_device *dev = port->serial->dev;
220 	unsigned urb_value;
221 	int status;
222 
223 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
224 		dev_dbg(&port->dev,
225 			"update_mctrl - DTR|RTS not being set|cleared\n");
226 		return 0;	/* no change */
227 	}
228 
229 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
230 	urb_value = 0;
231 	if (set & TIOCM_DTR)
232 		urb_value |= UART_MCR_DTR;
233 	if (set & TIOCM_RTS)
234 		urb_value |= UART_MCR_RTS;
235 
236 	status = qt2_setregister(dev, port_priv->device_port, UART_MCR,
237 				 urb_value);
238 	if (status < 0)
239 		dev_err(&port->dev,
240 			"update_mctrl - Error from MODEM_CTRL urb: %i\n",
241 			status);
242 	return status;
243 }
244 
245 static int qt2_calc_num_ports(struct usb_serial *serial,
246 					struct usb_serial_endpoints *epds)
247 {
248 	struct qt2_device_detail d;
249 	int i;
250 
251 	for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) {
252 		if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct))
253 			return d.num_ports;
254 	}
255 
256 	/* we didn't recognize the device */
257 	dev_err(&serial->dev->dev,
258 		 "don't know the number of ports, assuming 1\n");
259 
260 	return 1;
261 }
262 
263 static void qt2_set_termios(struct tty_struct *tty,
264 			    struct usb_serial_port *port,
265 			    struct ktermios *old_termios)
266 {
267 	struct usb_device *dev = port->serial->dev;
268 	struct qt2_port_private *port_priv;
269 	struct ktermios *termios = &tty->termios;
270 	u16 baud;
271 	unsigned int cflag = termios->c_cflag;
272 	u16 new_lcr = 0;
273 	int status;
274 
275 	port_priv = usb_get_serial_port_data(port);
276 
277 	if (cflag & PARENB) {
278 		if (cflag & PARODD)
279 			new_lcr |= UART_LCR_PARITY;
280 		else
281 			new_lcr |= SERIAL_EVEN_PARITY;
282 	}
283 
284 	new_lcr |= UART_LCR_WLEN(tty_get_char_size(cflag));
285 
286 	baud = tty_get_baud_rate(tty);
287 	if (!baud)
288 		baud = 9600;
289 
290 	status = qt2_set_port_config(dev, port_priv->device_port, baud,
291 				     new_lcr);
292 	if (status < 0)
293 		dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
294 			__func__, status);
295 
296 	if (cflag & CRTSCTS)
297 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
298 					 SERIAL_CRTSCTS,
299 					 port_priv->device_port);
300 	else
301 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
302 					 0, port_priv->device_port);
303 	if (status < 0)
304 		dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
305 			__func__, status);
306 
307 	if (I_IXOFF(tty) || I_IXON(tty)) {
308 		u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
309 
310 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
311 					 x, port_priv->device_port);
312 	} else
313 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
314 					 0, port_priv->device_port);
315 
316 	if (status < 0)
317 		dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
318 			__func__, status);
319 
320 }
321 
322 static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
323 {
324 	struct usb_serial *serial;
325 	struct qt2_port_private *port_priv;
326 	u8 *data;
327 	u16 device_port;
328 	int status;
329 	unsigned long flags;
330 
331 	device_port = port->port_number;
332 
333 	serial = port->serial;
334 
335 	port_priv = usb_get_serial_port_data(port);
336 
337 	/* set the port to RS232 mode */
338 	status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
339 				 QT2_QMCR_RS232, device_port);
340 	if (status < 0) {
341 		dev_err(&port->dev,
342 			"%s failed to set RS232 mode for port %i error %i\n",
343 			__func__, device_port, status);
344 		return status;
345 	}
346 
347 	data = kzalloc(2, GFP_KERNEL);
348 	if (!data)
349 		return -ENOMEM;
350 
351 	/* open the port */
352 	status = usb_control_msg(serial->dev,
353 				 usb_rcvctrlpipe(serial->dev, 0),
354 				 QT_OPEN_CLOSE_CHANNEL,
355 				 0xc0, 0,
356 				 device_port, data, 2, QT2_USB_TIMEOUT);
357 
358 	if (status < 2) {
359 		dev_err(&port->dev, "%s - open port failed %i\n", __func__,
360 			status);
361 		if (status >= 0)
362 			status = -EIO;
363 		kfree(data);
364 		return status;
365 	}
366 
367 	spin_lock_irqsave(&port_priv->lock, flags);
368 	port_priv->shadowLSR = data[0];
369 	port_priv->shadowMSR = data[1];
370 	spin_unlock_irqrestore(&port_priv->lock, flags);
371 
372 	kfree(data);
373 
374 	/* set to default speed and 8bit word size */
375 	status = qt2_set_port_config(serial->dev, device_port,
376 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
377 	if (status < 0) {
378 		dev_err(&port->dev, "%s - initial setup failed (%i)\n",
379 			__func__, device_port);
380 		return status;
381 	}
382 
383 	port_priv->device_port = (u8) device_port;
384 
385 	if (tty)
386 		qt2_set_termios(tty, port, &tty->termios);
387 
388 	return 0;
389 
390 }
391 
392 static void qt2_close(struct usb_serial_port *port)
393 {
394 	struct usb_serial *serial;
395 	struct qt2_port_private *port_priv;
396 	int i;
397 
398 	serial = port->serial;
399 	port_priv = usb_get_serial_port_data(port);
400 
401 	usb_kill_urb(port_priv->write_urb);
402 
403 	/* flush the port transmit buffer */
404 	i = usb_control_msg(serial->dev,
405 			    usb_sndctrlpipe(serial->dev, 0),
406 			    QT2_FLUSH_DEVICE, 0x40, 1,
407 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
408 
409 	if (i < 0)
410 		dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
411 			__func__, i);
412 
413 	/* flush the port receive buffer */
414 	i = usb_control_msg(serial->dev,
415 			    usb_sndctrlpipe(serial->dev, 0),
416 			    QT2_FLUSH_DEVICE, 0x40, 0,
417 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
418 
419 	if (i < 0)
420 		dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
421 			__func__, i);
422 
423 	/* close the port */
424 	i = usb_control_msg(serial->dev,
425 			    usb_sndctrlpipe(serial->dev, 0),
426 			    QT_OPEN_CLOSE_CHANNEL,
427 			    0x40, 0,
428 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
429 
430 	if (i < 0)
431 		dev_err(&port->dev, "%s - close port failed %i\n",
432 			__func__, i);
433 }
434 
435 static void qt2_disconnect(struct usb_serial *serial)
436 {
437 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
438 
439 	usb_kill_urb(serial_priv->read_urb);
440 }
441 
442 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
443 {
444 	switch (*ch) {
445 	case QT2_LINE_STATUS:
446 		qt2_update_lsr(port, ch + 1);
447 		break;
448 	case QT2_MODEM_STATUS:
449 		qt2_update_msr(port, ch + 1);
450 		break;
451 	}
452 }
453 
454 static void qt2_process_read_urb(struct urb *urb)
455 {
456 	struct usb_serial *serial;
457 	struct qt2_serial_private *serial_priv;
458 	struct usb_serial_port *port;
459 	bool escapeflag;
460 	unsigned char *ch;
461 	int i;
462 	unsigned char newport;
463 	int len = urb->actual_length;
464 
465 	if (!len)
466 		return;
467 
468 	ch = urb->transfer_buffer;
469 	serial = urb->context;
470 	serial_priv = usb_get_serial_data(serial);
471 	port = serial->port[serial_priv->current_port];
472 
473 	for (i = 0; i < urb->actual_length; i++) {
474 		ch = (unsigned char *)urb->transfer_buffer + i;
475 		if ((i <= (len - 3)) &&
476 		    (*ch == QT2_CONTROL_BYTE) &&
477 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
478 			escapeflag = false;
479 			switch (*(ch + 2)) {
480 			case QT2_LINE_STATUS:
481 			case QT2_MODEM_STATUS:
482 				if (i > (len - 4)) {
483 					dev_warn(&port->dev,
484 						 "%s - status message too short\n",
485 						__func__);
486 					break;
487 				}
488 				qt2_process_status(port, ch + 2);
489 				i += 3;
490 				escapeflag = true;
491 				break;
492 			case QT2_XMIT_HOLD:
493 				if (i > (len - 5)) {
494 					dev_warn(&port->dev,
495 						 "%s - xmit_empty message too short\n",
496 						 __func__);
497 					break;
498 				}
499 				/* bytes_written = (ch[1] << 4) + ch[0]; */
500 				i += 4;
501 				escapeflag = true;
502 				break;
503 			case QT2_CHANGE_PORT:
504 				if (i > (len - 4)) {
505 					dev_warn(&port->dev,
506 						 "%s - change_port message too short\n",
507 						 __func__);
508 					break;
509 				}
510 				tty_flip_buffer_push(&port->port);
511 
512 				newport = *(ch + 3);
513 
514 				if (newport > serial->num_ports) {
515 					dev_err(&port->dev,
516 						"%s - port change to invalid port: %i\n",
517 						__func__, newport);
518 					break;
519 				}
520 
521 				serial_priv->current_port = newport;
522 				port = serial->port[serial_priv->current_port];
523 				i += 3;
524 				escapeflag = true;
525 				break;
526 			case QT2_REC_FLUSH:
527 			case QT2_XMIT_FLUSH:
528 				i += 2;
529 				escapeflag = true;
530 				break;
531 			case QT2_CONTROL_ESCAPE:
532 				tty_insert_flip_string(&port->port, ch, 2);
533 				i += 2;
534 				escapeflag = true;
535 				break;
536 			default:
537 				dev_warn(&port->dev,
538 					 "%s - unsupported command %i\n",
539 					 __func__, *(ch + 2));
540 				break;
541 			}
542 			if (escapeflag)
543 				continue;
544 		}
545 
546 		tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
547 	}
548 
549 	tty_flip_buffer_push(&port->port);
550 }
551 
552 static void qt2_write_bulk_callback(struct urb *urb)
553 {
554 	struct usb_serial_port *port;
555 	struct qt2_port_private *port_priv;
556 	unsigned long flags;
557 
558 	port = urb->context;
559 	port_priv = usb_get_serial_port_data(port);
560 
561 	spin_lock_irqsave(&port_priv->urb_lock, flags);
562 
563 	port_priv->urb_in_use = false;
564 	usb_serial_port_softint(port);
565 
566 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
567 
568 }
569 
570 static void qt2_read_bulk_callback(struct urb *urb)
571 {
572 	struct usb_serial *serial = urb->context;
573 	int status;
574 
575 	if (urb->status) {
576 		dev_warn(&serial->dev->dev,
577 			 "%s - non-zero urb status: %i\n", __func__,
578 			 urb->status);
579 		return;
580 	}
581 
582 	qt2_process_read_urb(urb);
583 
584 	status = usb_submit_urb(urb, GFP_ATOMIC);
585 	if (status != 0)
586 		dev_err(&serial->dev->dev,
587 			"%s - resubmit read urb failed: %i\n",
588 			__func__, status);
589 }
590 
591 static int qt2_setup_urbs(struct usb_serial *serial)
592 {
593 	struct usb_serial_port *port0;
594 	struct qt2_serial_private *serial_priv;
595 	int status;
596 
597 	port0 = serial->port[0];
598 
599 	serial_priv = usb_get_serial_data(serial);
600 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
601 	if (!serial_priv->read_urb)
602 		return -ENOMEM;
603 
604 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
605 			  usb_rcvbulkpipe(serial->dev,
606 					  port0->bulk_in_endpointAddress),
607 			  serial_priv->read_buffer,
608 			  QT2_READ_BUFFER_SIZE,
609 			  qt2_read_bulk_callback, serial);
610 
611 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
612 	if (status != 0) {
613 		dev_err(&serial->dev->dev,
614 			"%s - submit read urb failed %i\n", __func__, status);
615 		usb_free_urb(serial_priv->read_urb);
616 		return status;
617 	}
618 
619 	return 0;
620 }
621 
622 static int qt2_attach(struct usb_serial *serial)
623 {
624 	struct qt2_serial_private *serial_priv;
625 	int status;
626 
627 	/* power on unit */
628 	status = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
629 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
630 				 QT2_USB_TIMEOUT);
631 	if (status < 0) {
632 		dev_err(&serial->dev->dev,
633 			"%s - failed to power on unit: %i\n", __func__, status);
634 		return status;
635 	}
636 
637 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
638 	if (!serial_priv)
639 		return -ENOMEM;
640 
641 	serial_priv->read_buffer = kmalloc(QT2_READ_BUFFER_SIZE, GFP_KERNEL);
642 	if (!serial_priv->read_buffer) {
643 		status = -ENOMEM;
644 		goto err_buf;
645 	}
646 
647 	usb_set_serial_data(serial, serial_priv);
648 
649 	status = qt2_setup_urbs(serial);
650 	if (status != 0)
651 		goto attach_failed;
652 
653 	return 0;
654 
655 attach_failed:
656 	kfree(serial_priv->read_buffer);
657 err_buf:
658 	kfree(serial_priv);
659 	return status;
660 }
661 
662 static int qt2_port_probe(struct usb_serial_port *port)
663 {
664 	struct usb_serial *serial = port->serial;
665 	struct qt2_port_private *port_priv;
666 	u8 bEndpointAddress;
667 
668 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
669 	if (!port_priv)
670 		return -ENOMEM;
671 
672 	spin_lock_init(&port_priv->lock);
673 	spin_lock_init(&port_priv->urb_lock);
674 	port_priv->port = port;
675 
676 	port_priv->write_buffer = kmalloc(QT2_WRITE_BUFFER_SIZE, GFP_KERNEL);
677 	if (!port_priv->write_buffer)
678 		goto err_buf;
679 
680 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
681 	if (!port_priv->write_urb)
682 		goto err_urb;
683 
684 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
685 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
686 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
687 				port_priv->write_buffer,
688 				QT2_WRITE_BUFFER_SIZE,
689 				qt2_write_bulk_callback, port);
690 
691 	usb_set_serial_port_data(port, port_priv);
692 
693 	return 0;
694 err_urb:
695 	kfree(port_priv->write_buffer);
696 err_buf:
697 	kfree(port_priv);
698 	return -ENOMEM;
699 }
700 
701 static void qt2_port_remove(struct usb_serial_port *port)
702 {
703 	struct qt2_port_private *port_priv;
704 
705 	port_priv = usb_get_serial_port_data(port);
706 	usb_free_urb(port_priv->write_urb);
707 	kfree(port_priv->write_buffer);
708 	kfree(port_priv);
709 }
710 
711 static int qt2_tiocmget(struct tty_struct *tty)
712 {
713 	struct usb_serial_port *port = tty->driver_data;
714 	struct usb_device *dev = port->serial->dev;
715 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
716 	u8 *d;
717 	int r;
718 
719 	d = kzalloc(2, GFP_KERNEL);
720 	if (!d)
721 		return -ENOMEM;
722 
723 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
724 	if (r < 0)
725 		goto mget_out;
726 
727 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
728 	if (r < 0)
729 		goto mget_out;
730 
731 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
732 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
733 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
734 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
735 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
736 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
737 
738 mget_out:
739 	kfree(d);
740 	return r;
741 }
742 
743 static int qt2_tiocmset(struct tty_struct *tty,
744 			unsigned int set, unsigned int clear)
745 {
746 	struct qt2_port_private *port_priv;
747 
748 	port_priv = usb_get_serial_port_data(tty->driver_data);
749 	return update_mctrl(port_priv, set, clear);
750 }
751 
752 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
753 {
754 	struct usb_serial_port *port = tty->driver_data;
755 	struct qt2_port_private *port_priv;
756 	int status;
757 	u16 val;
758 
759 	port_priv = usb_get_serial_port_data(port);
760 
761 	val = (break_state == -1) ? 1 : 0;
762 
763 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
764 				 val, port_priv->device_port);
765 	if (status < 0)
766 		dev_warn(&port->dev,
767 			 "%s - failed to send control message: %i\n", __func__,
768 			 status);
769 }
770 
771 
772 
773 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
774 {
775 	struct usb_device *dev = port->serial->dev;
776 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
777 
778 	/* Disable flow control */
779 	if (!on) {
780 		if (qt2_setregister(dev, port_priv->device_port,
781 					   UART_MCR, 0) < 0)
782 			dev_warn(&port->dev, "error from flowcontrol urb\n");
783 	}
784 	/* drop RTS and DTR */
785 	if (on)
786 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
787 	else
788 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
789 }
790 
791 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
792 {
793 	struct qt2_port_private *port_priv;
794 	u8 newMSR = (u8) *ch;
795 	unsigned long flags;
796 
797 	/* May be called from qt2_process_read_urb() for an unbound port. */
798 	port_priv = usb_get_serial_port_data(port);
799 	if (!port_priv)
800 		return;
801 
802 	spin_lock_irqsave(&port_priv->lock, flags);
803 	port_priv->shadowMSR = newMSR;
804 	spin_unlock_irqrestore(&port_priv->lock, flags);
805 
806 	if (newMSR & UART_MSR_ANY_DELTA) {
807 		/* update input line counters */
808 		if (newMSR & UART_MSR_DCTS)
809 			port->icount.cts++;
810 		if (newMSR & UART_MSR_DDSR)
811 			port->icount.dsr++;
812 		if (newMSR & UART_MSR_DDCD)
813 			port->icount.dcd++;
814 		if (newMSR & UART_MSR_TERI)
815 			port->icount.rng++;
816 
817 		wake_up_interruptible(&port->port.delta_msr_wait);
818 	}
819 }
820 
821 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
822 {
823 	struct qt2_port_private *port_priv;
824 	struct async_icount *icount;
825 	unsigned long flags;
826 	u8 newLSR = (u8) *ch;
827 
828 	/* May be called from qt2_process_read_urb() for an unbound port. */
829 	port_priv = usb_get_serial_port_data(port);
830 	if (!port_priv)
831 		return;
832 
833 	if (newLSR & UART_LSR_BI)
834 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
835 
836 	spin_lock_irqsave(&port_priv->lock, flags);
837 	port_priv->shadowLSR = newLSR;
838 	spin_unlock_irqrestore(&port_priv->lock, flags);
839 
840 	icount = &port->icount;
841 
842 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
843 
844 		if (newLSR & UART_LSR_BI)
845 			icount->brk++;
846 
847 		if (newLSR & UART_LSR_OE)
848 			icount->overrun++;
849 
850 		if (newLSR & UART_LSR_PE)
851 			icount->parity++;
852 
853 		if (newLSR & UART_LSR_FE)
854 			icount->frame++;
855 	}
856 
857 }
858 
859 static unsigned int qt2_write_room(struct tty_struct *tty)
860 {
861 	struct usb_serial_port *port = tty->driver_data;
862 	struct qt2_port_private *port_priv;
863 	unsigned long flags;
864 	unsigned int r;
865 
866 	port_priv = usb_get_serial_port_data(port);
867 
868 	spin_lock_irqsave(&port_priv->urb_lock, flags);
869 
870 	if (port_priv->urb_in_use)
871 		r = 0;
872 	else
873 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
874 
875 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
876 
877 	return r;
878 }
879 
880 static int qt2_write(struct tty_struct *tty,
881 		     struct usb_serial_port *port,
882 		     const unsigned char *buf, int count)
883 {
884 	struct qt2_port_private *port_priv;
885 	struct urb *write_urb;
886 	unsigned char *data;
887 	unsigned long flags;
888 	int status;
889 	int bytes_out = 0;
890 
891 	port_priv = usb_get_serial_port_data(port);
892 
893 	if (port_priv->write_urb == NULL) {
894 		dev_err(&port->dev, "%s - no output urb\n", __func__);
895 		return 0;
896 	}
897 	write_urb = port_priv->write_urb;
898 
899 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
900 
901 	data = write_urb->transfer_buffer;
902 	spin_lock_irqsave(&port_priv->urb_lock, flags);
903 	if (port_priv->urb_in_use) {
904 		dev_err(&port->dev, "qt2_write - urb is in use\n");
905 		goto write_out;
906 	}
907 
908 	*data++ = QT2_CONTROL_BYTE;
909 	*data++ = QT2_CONTROL_BYTE;
910 	*data++ = port_priv->device_port;
911 	put_unaligned_le16(count, data);
912 	data += 2;
913 	memcpy(data, buf, count);
914 
915 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
916 
917 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
918 	if (status == 0) {
919 		port_priv->urb_in_use = true;
920 		bytes_out += count;
921 	}
922 
923 write_out:
924 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
925 	return bytes_out;
926 }
927 
928 
929 static struct usb_serial_driver qt2_device = {
930 	.driver = {
931 		.owner = THIS_MODULE,
932 		.name = "quatech-serial",
933 	},
934 	.description	     = DRIVER_DESC,
935 	.id_table	     = id_table,
936 	.open		     = qt2_open,
937 	.close		     = qt2_close,
938 	.write               = qt2_write,
939 	.write_room          = qt2_write_room,
940 	.calc_num_ports      = qt2_calc_num_ports,
941 	.attach              = qt2_attach,
942 	.release             = qt2_release,
943 	.disconnect          = qt2_disconnect,
944 	.port_probe          = qt2_port_probe,
945 	.port_remove         = qt2_port_remove,
946 	.dtr_rts             = qt2_dtr_rts,
947 	.break_ctl           = qt2_break_ctl,
948 	.tiocmget            = qt2_tiocmget,
949 	.tiocmset            = qt2_tiocmset,
950 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
951 	.get_icount	     = usb_serial_generic_get_icount,
952 	.set_termios         = qt2_set_termios,
953 };
954 
955 static struct usb_serial_driver *const serial_drivers[] = {
956 	&qt2_device, NULL
957 };
958 
959 module_usb_serial_driver(serial_drivers, id_table);
960 
961 MODULE_DESCRIPTION(DRIVER_DESC);
962 MODULE_LICENSE("GPL v2");
963