xref: /openbmc/linux/drivers/usb/serial/quatech2.c (revision 79e790ff)
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 	switch (cflag & CSIZE) {
285 	case CS5:
286 		new_lcr |= UART_LCR_WLEN5;
287 		break;
288 	case CS6:
289 		new_lcr |= UART_LCR_WLEN6;
290 		break;
291 	case CS7:
292 		new_lcr |= UART_LCR_WLEN7;
293 		break;
294 	default:
295 	case CS8:
296 		new_lcr |= UART_LCR_WLEN8;
297 		break;
298 	}
299 
300 	baud = tty_get_baud_rate(tty);
301 	if (!baud)
302 		baud = 9600;
303 
304 	status = qt2_set_port_config(dev, port_priv->device_port, baud,
305 				     new_lcr);
306 	if (status < 0)
307 		dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
308 			__func__, status);
309 
310 	if (cflag & CRTSCTS)
311 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
312 					 SERIAL_CRTSCTS,
313 					 port_priv->device_port);
314 	else
315 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
316 					 0, port_priv->device_port);
317 	if (status < 0)
318 		dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
319 			__func__, status);
320 
321 	if (I_IXOFF(tty) || I_IXON(tty)) {
322 		u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
323 
324 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
325 					 x, port_priv->device_port);
326 	} else
327 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
328 					 0, port_priv->device_port);
329 
330 	if (status < 0)
331 		dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
332 			__func__, status);
333 
334 }
335 
336 static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
337 {
338 	struct usb_serial *serial;
339 	struct qt2_port_private *port_priv;
340 	u8 *data;
341 	u16 device_port;
342 	int status;
343 	unsigned long flags;
344 
345 	device_port = port->port_number;
346 
347 	serial = port->serial;
348 
349 	port_priv = usb_get_serial_port_data(port);
350 
351 	/* set the port to RS232 mode */
352 	status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
353 				 QT2_QMCR_RS232, device_port);
354 	if (status < 0) {
355 		dev_err(&port->dev,
356 			"%s failed to set RS232 mode for port %i error %i\n",
357 			__func__, device_port, status);
358 		return status;
359 	}
360 
361 	data = kzalloc(2, GFP_KERNEL);
362 	if (!data)
363 		return -ENOMEM;
364 
365 	/* open the port */
366 	status = usb_control_msg(serial->dev,
367 				 usb_rcvctrlpipe(serial->dev, 0),
368 				 QT_OPEN_CLOSE_CHANNEL,
369 				 0xc0, 0,
370 				 device_port, data, 2, QT2_USB_TIMEOUT);
371 
372 	if (status < 2) {
373 		dev_err(&port->dev, "%s - open port failed %i\n", __func__,
374 			status);
375 		if (status >= 0)
376 			status = -EIO;
377 		kfree(data);
378 		return status;
379 	}
380 
381 	spin_lock_irqsave(&port_priv->lock, flags);
382 	port_priv->shadowLSR = data[0];
383 	port_priv->shadowMSR = data[1];
384 	spin_unlock_irqrestore(&port_priv->lock, flags);
385 
386 	kfree(data);
387 
388 	/* set to default speed and 8bit word size */
389 	status = qt2_set_port_config(serial->dev, device_port,
390 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
391 	if (status < 0) {
392 		dev_err(&port->dev, "%s - initial setup failed (%i)\n",
393 			__func__, device_port);
394 		return status;
395 	}
396 
397 	port_priv->device_port = (u8) device_port;
398 
399 	if (tty)
400 		qt2_set_termios(tty, port, &tty->termios);
401 
402 	return 0;
403 
404 }
405 
406 static void qt2_close(struct usb_serial_port *port)
407 {
408 	struct usb_serial *serial;
409 	struct qt2_port_private *port_priv;
410 	int i;
411 
412 	serial = port->serial;
413 	port_priv = usb_get_serial_port_data(port);
414 
415 	usb_kill_urb(port_priv->write_urb);
416 
417 	/* flush the port transmit buffer */
418 	i = usb_control_msg(serial->dev,
419 			    usb_rcvctrlpipe(serial->dev, 0),
420 			    QT2_FLUSH_DEVICE, 0x40, 1,
421 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
422 
423 	if (i < 0)
424 		dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
425 			__func__, i);
426 
427 	/* flush the port receive buffer */
428 	i = usb_control_msg(serial->dev,
429 			    usb_rcvctrlpipe(serial->dev, 0),
430 			    QT2_FLUSH_DEVICE, 0x40, 0,
431 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
432 
433 	if (i < 0)
434 		dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
435 			__func__, i);
436 
437 	/* close the port */
438 	i = usb_control_msg(serial->dev,
439 			    usb_sndctrlpipe(serial->dev, 0),
440 			    QT_OPEN_CLOSE_CHANNEL,
441 			    0x40, 0,
442 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
443 
444 	if (i < 0)
445 		dev_err(&port->dev, "%s - close port failed %i\n",
446 			__func__, i);
447 }
448 
449 static void qt2_disconnect(struct usb_serial *serial)
450 {
451 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
452 
453 	usb_kill_urb(serial_priv->read_urb);
454 }
455 
456 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
457 {
458 	switch (*ch) {
459 	case QT2_LINE_STATUS:
460 		qt2_update_lsr(port, ch + 1);
461 		break;
462 	case QT2_MODEM_STATUS:
463 		qt2_update_msr(port, ch + 1);
464 		break;
465 	}
466 }
467 
468 static void qt2_process_read_urb(struct urb *urb)
469 {
470 	struct usb_serial *serial;
471 	struct qt2_serial_private *serial_priv;
472 	struct usb_serial_port *port;
473 	bool escapeflag;
474 	unsigned char *ch;
475 	int i;
476 	unsigned char newport;
477 	int len = urb->actual_length;
478 
479 	if (!len)
480 		return;
481 
482 	ch = urb->transfer_buffer;
483 	serial = urb->context;
484 	serial_priv = usb_get_serial_data(serial);
485 	port = serial->port[serial_priv->current_port];
486 
487 	for (i = 0; i < urb->actual_length; i++) {
488 		ch = (unsigned char *)urb->transfer_buffer + i;
489 		if ((i <= (len - 3)) &&
490 		    (*ch == QT2_CONTROL_BYTE) &&
491 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
492 			escapeflag = false;
493 			switch (*(ch + 2)) {
494 			case QT2_LINE_STATUS:
495 			case QT2_MODEM_STATUS:
496 				if (i > (len - 4)) {
497 					dev_warn(&port->dev,
498 						 "%s - status message too short\n",
499 						__func__);
500 					break;
501 				}
502 				qt2_process_status(port, ch + 2);
503 				i += 3;
504 				escapeflag = true;
505 				break;
506 			case QT2_XMIT_HOLD:
507 				if (i > (len - 5)) {
508 					dev_warn(&port->dev,
509 						 "%s - xmit_empty message too short\n",
510 						 __func__);
511 					break;
512 				}
513 				/* bytes_written = (ch[1] << 4) + ch[0]; */
514 				i += 4;
515 				escapeflag = true;
516 				break;
517 			case QT2_CHANGE_PORT:
518 				if (i > (len - 4)) {
519 					dev_warn(&port->dev,
520 						 "%s - change_port message too short\n",
521 						 __func__);
522 					break;
523 				}
524 				tty_flip_buffer_push(&port->port);
525 
526 				newport = *(ch + 3);
527 
528 				if (newport > serial->num_ports) {
529 					dev_err(&port->dev,
530 						"%s - port change to invalid port: %i\n",
531 						__func__, newport);
532 					break;
533 				}
534 
535 				serial_priv->current_port = newport;
536 				port = serial->port[serial_priv->current_port];
537 				i += 3;
538 				escapeflag = true;
539 				break;
540 			case QT2_REC_FLUSH:
541 			case QT2_XMIT_FLUSH:
542 				i += 2;
543 				escapeflag = true;
544 				break;
545 			case QT2_CONTROL_ESCAPE:
546 				tty_insert_flip_string(&port->port, ch, 2);
547 				i += 2;
548 				escapeflag = true;
549 				break;
550 			default:
551 				dev_warn(&port->dev,
552 					 "%s - unsupported command %i\n",
553 					 __func__, *(ch + 2));
554 				break;
555 			}
556 			if (escapeflag)
557 				continue;
558 		}
559 
560 		tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
561 	}
562 
563 	tty_flip_buffer_push(&port->port);
564 }
565 
566 static void qt2_write_bulk_callback(struct urb *urb)
567 {
568 	struct usb_serial_port *port;
569 	struct qt2_port_private *port_priv;
570 	unsigned long flags;
571 
572 	port = urb->context;
573 	port_priv = usb_get_serial_port_data(port);
574 
575 	spin_lock_irqsave(&port_priv->urb_lock, flags);
576 
577 	port_priv->urb_in_use = false;
578 	usb_serial_port_softint(port);
579 
580 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
581 
582 }
583 
584 static void qt2_read_bulk_callback(struct urb *urb)
585 {
586 	struct usb_serial *serial = urb->context;
587 	int status;
588 
589 	if (urb->status) {
590 		dev_warn(&serial->dev->dev,
591 			 "%s - non-zero urb status: %i\n", __func__,
592 			 urb->status);
593 		return;
594 	}
595 
596 	qt2_process_read_urb(urb);
597 
598 	status = usb_submit_urb(urb, GFP_ATOMIC);
599 	if (status != 0)
600 		dev_err(&serial->dev->dev,
601 			"%s - resubmit read urb failed: %i\n",
602 			__func__, status);
603 }
604 
605 static int qt2_setup_urbs(struct usb_serial *serial)
606 {
607 	struct usb_serial_port *port0;
608 	struct qt2_serial_private *serial_priv;
609 	int status;
610 
611 	port0 = serial->port[0];
612 
613 	serial_priv = usb_get_serial_data(serial);
614 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
615 	if (!serial_priv->read_urb)
616 		return -ENOMEM;
617 
618 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
619 			  usb_rcvbulkpipe(serial->dev,
620 					  port0->bulk_in_endpointAddress),
621 			  serial_priv->read_buffer,
622 			  QT2_READ_BUFFER_SIZE,
623 			  qt2_read_bulk_callback, serial);
624 
625 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
626 	if (status != 0) {
627 		dev_err(&serial->dev->dev,
628 			"%s - submit read urb failed %i\n", __func__, status);
629 		usb_free_urb(serial_priv->read_urb);
630 		return status;
631 	}
632 
633 	return 0;
634 }
635 
636 static int qt2_attach(struct usb_serial *serial)
637 {
638 	struct qt2_serial_private *serial_priv;
639 	int status;
640 
641 	/* power on unit */
642 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
643 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
644 				 QT2_USB_TIMEOUT);
645 	if (status < 0) {
646 		dev_err(&serial->dev->dev,
647 			"%s - failed to power on unit: %i\n", __func__, status);
648 		return status;
649 	}
650 
651 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
652 	if (!serial_priv)
653 		return -ENOMEM;
654 
655 	serial_priv->read_buffer = kmalloc(QT2_READ_BUFFER_SIZE, GFP_KERNEL);
656 	if (!serial_priv->read_buffer) {
657 		status = -ENOMEM;
658 		goto err_buf;
659 	}
660 
661 	usb_set_serial_data(serial, serial_priv);
662 
663 	status = qt2_setup_urbs(serial);
664 	if (status != 0)
665 		goto attach_failed;
666 
667 	return 0;
668 
669 attach_failed:
670 	kfree(serial_priv->read_buffer);
671 err_buf:
672 	kfree(serial_priv);
673 	return status;
674 }
675 
676 static int qt2_port_probe(struct usb_serial_port *port)
677 {
678 	struct usb_serial *serial = port->serial;
679 	struct qt2_port_private *port_priv;
680 	u8 bEndpointAddress;
681 
682 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
683 	if (!port_priv)
684 		return -ENOMEM;
685 
686 	spin_lock_init(&port_priv->lock);
687 	spin_lock_init(&port_priv->urb_lock);
688 	port_priv->port = port;
689 
690 	port_priv->write_buffer = kmalloc(QT2_WRITE_BUFFER_SIZE, GFP_KERNEL);
691 	if (!port_priv->write_buffer)
692 		goto err_buf;
693 
694 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
695 	if (!port_priv->write_urb)
696 		goto err_urb;
697 
698 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
699 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
700 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
701 				port_priv->write_buffer,
702 				QT2_WRITE_BUFFER_SIZE,
703 				qt2_write_bulk_callback, port);
704 
705 	usb_set_serial_port_data(port, port_priv);
706 
707 	return 0;
708 err_urb:
709 	kfree(port_priv->write_buffer);
710 err_buf:
711 	kfree(port_priv);
712 	return -ENOMEM;
713 }
714 
715 static void qt2_port_remove(struct usb_serial_port *port)
716 {
717 	struct qt2_port_private *port_priv;
718 
719 	port_priv = usb_get_serial_port_data(port);
720 	usb_free_urb(port_priv->write_urb);
721 	kfree(port_priv->write_buffer);
722 	kfree(port_priv);
723 }
724 
725 static int qt2_tiocmget(struct tty_struct *tty)
726 {
727 	struct usb_serial_port *port = tty->driver_data;
728 	struct usb_device *dev = port->serial->dev;
729 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
730 	u8 *d;
731 	int r;
732 
733 	d = kzalloc(2, GFP_KERNEL);
734 	if (!d)
735 		return -ENOMEM;
736 
737 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
738 	if (r < 0)
739 		goto mget_out;
740 
741 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
742 	if (r < 0)
743 		goto mget_out;
744 
745 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
746 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
747 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
748 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
749 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
750 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
751 
752 mget_out:
753 	kfree(d);
754 	return r;
755 }
756 
757 static int qt2_tiocmset(struct tty_struct *tty,
758 			unsigned int set, unsigned int clear)
759 {
760 	struct qt2_port_private *port_priv;
761 
762 	port_priv = usb_get_serial_port_data(tty->driver_data);
763 	return update_mctrl(port_priv, set, clear);
764 }
765 
766 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
767 {
768 	struct usb_serial_port *port = tty->driver_data;
769 	struct qt2_port_private *port_priv;
770 	int status;
771 	u16 val;
772 
773 	port_priv = usb_get_serial_port_data(port);
774 
775 	val = (break_state == -1) ? 1 : 0;
776 
777 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
778 				 val, port_priv->device_port);
779 	if (status < 0)
780 		dev_warn(&port->dev,
781 			 "%s - failed to send control message: %i\n", __func__,
782 			 status);
783 }
784 
785 
786 
787 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
788 {
789 	struct usb_device *dev = port->serial->dev;
790 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
791 
792 	/* Disable flow control */
793 	if (!on) {
794 		if (qt2_setregister(dev, port_priv->device_port,
795 					   UART_MCR, 0) < 0)
796 			dev_warn(&port->dev, "error from flowcontrol urb\n");
797 	}
798 	/* drop RTS and DTR */
799 	if (on)
800 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
801 	else
802 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
803 }
804 
805 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
806 {
807 	struct qt2_port_private *port_priv;
808 	u8 newMSR = (u8) *ch;
809 	unsigned long flags;
810 
811 	/* May be called from qt2_process_read_urb() for an unbound port. */
812 	port_priv = usb_get_serial_port_data(port);
813 	if (!port_priv)
814 		return;
815 
816 	spin_lock_irqsave(&port_priv->lock, flags);
817 	port_priv->shadowMSR = newMSR;
818 	spin_unlock_irqrestore(&port_priv->lock, flags);
819 
820 	if (newMSR & UART_MSR_ANY_DELTA) {
821 		/* update input line counters */
822 		if (newMSR & UART_MSR_DCTS)
823 			port->icount.cts++;
824 		if (newMSR & UART_MSR_DDSR)
825 			port->icount.dsr++;
826 		if (newMSR & UART_MSR_DDCD)
827 			port->icount.dcd++;
828 		if (newMSR & UART_MSR_TERI)
829 			port->icount.rng++;
830 
831 		wake_up_interruptible(&port->port.delta_msr_wait);
832 	}
833 }
834 
835 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
836 {
837 	struct qt2_port_private *port_priv;
838 	struct async_icount *icount;
839 	unsigned long flags;
840 	u8 newLSR = (u8) *ch;
841 
842 	/* May be called from qt2_process_read_urb() for an unbound port. */
843 	port_priv = usb_get_serial_port_data(port);
844 	if (!port_priv)
845 		return;
846 
847 	if (newLSR & UART_LSR_BI)
848 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
849 
850 	spin_lock_irqsave(&port_priv->lock, flags);
851 	port_priv->shadowLSR = newLSR;
852 	spin_unlock_irqrestore(&port_priv->lock, flags);
853 
854 	icount = &port->icount;
855 
856 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
857 
858 		if (newLSR & UART_LSR_BI)
859 			icount->brk++;
860 
861 		if (newLSR & UART_LSR_OE)
862 			icount->overrun++;
863 
864 		if (newLSR & UART_LSR_PE)
865 			icount->parity++;
866 
867 		if (newLSR & UART_LSR_FE)
868 			icount->frame++;
869 	}
870 
871 }
872 
873 static int qt2_write_room(struct tty_struct *tty)
874 {
875 	struct usb_serial_port *port = tty->driver_data;
876 	struct qt2_port_private *port_priv;
877 	unsigned long flags = 0;
878 	int r;
879 
880 	port_priv = usb_get_serial_port_data(port);
881 
882 	spin_lock_irqsave(&port_priv->urb_lock, flags);
883 
884 	if (port_priv->urb_in_use)
885 		r = 0;
886 	else
887 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
888 
889 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
890 
891 	return r;
892 }
893 
894 static int qt2_write(struct tty_struct *tty,
895 		     struct usb_serial_port *port,
896 		     const unsigned char *buf, int count)
897 {
898 	struct qt2_port_private *port_priv;
899 	struct urb *write_urb;
900 	unsigned char *data;
901 	unsigned long flags;
902 	int status;
903 	int bytes_out = 0;
904 
905 	port_priv = usb_get_serial_port_data(port);
906 
907 	if (port_priv->write_urb == NULL) {
908 		dev_err(&port->dev, "%s - no output urb\n", __func__);
909 		return 0;
910 	}
911 	write_urb = port_priv->write_urb;
912 
913 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
914 
915 	data = write_urb->transfer_buffer;
916 	spin_lock_irqsave(&port_priv->urb_lock, flags);
917 	if (port_priv->urb_in_use) {
918 		dev_err(&port->dev, "qt2_write - urb is in use\n");
919 		goto write_out;
920 	}
921 
922 	*data++ = QT2_CONTROL_BYTE;
923 	*data++ = QT2_CONTROL_BYTE;
924 	*data++ = port_priv->device_port;
925 	put_unaligned_le16(count, data);
926 	data += 2;
927 	memcpy(data, buf, count);
928 
929 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
930 
931 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
932 	if (status == 0) {
933 		port_priv->urb_in_use = true;
934 		bytes_out += count;
935 	}
936 
937 write_out:
938 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
939 	return bytes_out;
940 }
941 
942 
943 static struct usb_serial_driver qt2_device = {
944 	.driver = {
945 		.owner = THIS_MODULE,
946 		.name = "quatech-serial",
947 	},
948 	.description	     = DRIVER_DESC,
949 	.id_table	     = id_table,
950 	.open		     = qt2_open,
951 	.close		     = qt2_close,
952 	.write               = qt2_write,
953 	.write_room          = qt2_write_room,
954 	.calc_num_ports      = qt2_calc_num_ports,
955 	.attach              = qt2_attach,
956 	.release             = qt2_release,
957 	.disconnect          = qt2_disconnect,
958 	.port_probe          = qt2_port_probe,
959 	.port_remove         = qt2_port_remove,
960 	.dtr_rts             = qt2_dtr_rts,
961 	.break_ctl           = qt2_break_ctl,
962 	.tiocmget            = qt2_tiocmget,
963 	.tiocmset            = qt2_tiocmset,
964 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
965 	.get_icount	     = usb_serial_generic_get_icount,
966 	.set_termios         = qt2_set_termios,
967 };
968 
969 static struct usb_serial_driver *const serial_drivers[] = {
970 	&qt2_device, NULL
971 };
972 
973 module_usb_serial_driver(serial_drivers, id_table);
974 
975 MODULE_DESCRIPTION(DRIVER_DESC);
976 MODULE_LICENSE("GPL v2");
977