xref: /linux/drivers/usb/serial/quatech2.c (revision 32786fdc9506aeba98278c1844d4bfb766863832)
1 /*
2  * usb-serial driver for Quatech USB 2 devices
3  *
4  * Copyright (C) 2012 Bill Pemberton (wfp5p@virginia.edu)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version 2
8  * as published by the Free Software Foundation.
9  *
10  *
11  *  These devices all have only 1 bulk in and 1 bulk out that is shared
12  *  for all serial ports.
13  *
14  */
15 
16 #include <asm/unaligned.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/tty.h>
20 #include <linux/tty_driver.h>
21 #include <linux/tty_flip.h>
22 #include <linux/module.h>
23 #include <linux/serial.h>
24 #include <linux/usb.h>
25 #include <linux/usb/serial.h>
26 #include <linux/serial_reg.h>
27 #include <linux/uaccess.h>
28 
29 /* default urb timeout for usb operations */
30 #define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT
31 
32 #define QT_OPEN_CLOSE_CHANNEL       0xca
33 #define QT_SET_GET_DEVICE           0xc2
34 #define QT_SET_GET_REGISTER         0xc0
35 #define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
36 #define QT_SET_ATF                  0xcd
37 #define QT_TRANSFER_IN              0xc0
38 #define QT_HW_FLOW_CONTROL_MASK     0xc5
39 #define QT_SW_FLOW_CONTROL_MASK     0xc6
40 #define QT2_BREAK_CONTROL	    0xc8
41 #define QT2_GET_SET_UART            0xc1
42 #define QT2_FLUSH_DEVICE	    0xc4
43 #define QT2_GET_SET_QMCR            0xe1
44 #define QT2_QMCR_RS232              0x40
45 #define QT2_QMCR_RS422              0x10
46 
47 #define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
48 
49 #define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
50 
51 /* status bytes for the device */
52 #define QT2_CONTROL_BYTE    0x1b
53 #define QT2_LINE_STATUS     0x00  /* following 1 byte is line status */
54 #define QT2_MODEM_STATUS    0x01  /* following 1 byte is modem status */
55 #define QT2_XMIT_HOLD       0x02  /* following 2 bytes are ?? */
56 #define QT2_CHANGE_PORT     0x03  /* following 1 byte is port to change to */
57 #define QT2_REC_FLUSH       0x04  /* no following info */
58 #define QT2_XMIT_FLUSH      0x05  /* no following info */
59 #define QT2_CONTROL_ESCAPE  0xff  /* pass through previous 2 control bytes */
60 
61 #define  MAX_BAUD_RATE              921600
62 #define  DEFAULT_BAUD_RATE          9600
63 
64 #define QT2_READ_BUFFER_SIZE    512  /* size of read buffer */
65 #define QT2_WRITE_BUFFER_SIZE   512  /* size of write buffer */
66 #define QT2_WRITE_CONTROL_SIZE  5    /* control bytes used for a write */
67 
68 #define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver"
69 
70 #define	USB_VENDOR_ID_QUATECH	0x061d
71 #define QUATECH_SSU2_100	0xC120	/* RS232 single port */
72 #define QUATECH_DSU2_100	0xC140	/* RS232 dual port */
73 #define QUATECH_DSU2_400	0xC150	/* RS232/422/485 dual port */
74 #define QUATECH_QSU2_100	0xC160	/* RS232 four port */
75 #define QUATECH_QSU2_400	0xC170	/* RS232/422/485 four port */
76 #define QUATECH_ESU2_100	0xC1A0	/* RS232 eight port */
77 #define QUATECH_ESU2_400	0xC180	/* RS232/422/485 eight port */
78 
79 struct qt2_device_detail {
80 	int product_id;
81 	int num_ports;
82 };
83 
84 #define QT_DETAILS(prod, ports)	\
85 	.product_id = (prod),   \
86 	.num_ports = (ports)
87 
88 static const struct qt2_device_detail qt2_device_details[] = {
89 	{QT_DETAILS(QUATECH_SSU2_100, 1)},
90 	{QT_DETAILS(QUATECH_DSU2_400, 2)},
91 	{QT_DETAILS(QUATECH_DSU2_100, 2)},
92 	{QT_DETAILS(QUATECH_QSU2_400, 4)},
93 	{QT_DETAILS(QUATECH_QSU2_100, 4)},
94 	{QT_DETAILS(QUATECH_ESU2_400, 8)},
95 	{QT_DETAILS(QUATECH_ESU2_100, 8)},
96 	{QT_DETAILS(0, 0)}	/* Terminating entry */
97 };
98 
99 static const struct usb_device_id id_table[] = {
100 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)},
101 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)},
102 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)},
103 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)},
104 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)},
105 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)},
106 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)},
107 	{}			/* Terminating entry */
108 };
109 MODULE_DEVICE_TABLE(usb, id_table);
110 
111 struct qt2_serial_private {
112 	unsigned char current_port;  /* current port for incoming data */
113 
114 	struct urb	*read_urb;   /* shared among all ports */
115 	char		*read_buffer;
116 };
117 
118 struct qt2_port_private {
119 	u8   device_port;
120 
121 	spinlock_t urb_lock;
122 	bool       urb_in_use;
123 	struct urb *write_urb;
124 	char       *write_buffer;
125 
126 	spinlock_t  lock;
127 	u8          shadowLSR;
128 	u8          shadowMSR;
129 
130 	struct usb_serial_port *port;
131 };
132 
133 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
134 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
135 static void qt2_write_bulk_callback(struct urb *urb);
136 static void qt2_read_bulk_callback(struct urb *urb);
137 
138 static void qt2_release(struct usb_serial *serial)
139 {
140 	struct qt2_serial_private *serial_priv;
141 
142 	serial_priv = usb_get_serial_data(serial);
143 
144 	usb_kill_urb(serial_priv->read_urb);
145 	usb_free_urb(serial_priv->read_urb);
146 	kfree(serial_priv->read_buffer);
147 	kfree(serial_priv);
148 }
149 
150 static inline int calc_baud_divisor(int baudrate)
151 {
152 	int divisor, rem;
153 
154 	divisor = MAX_BAUD_RATE / baudrate;
155 	rem = MAX_BAUD_RATE % baudrate;
156 	/* Round to nearest divisor */
157 	if (((rem * 2) >= baudrate) && (baudrate != 110))
158 		divisor++;
159 
160 	return divisor;
161 }
162 
163 static inline int qt2_set_port_config(struct usb_device *dev,
164 				      unsigned char port_number,
165 				      u16 baudrate, u16 lcr)
166 {
167 	int divisor = calc_baud_divisor(baudrate);
168 	u16 index = ((u16) (lcr << 8) | (u16) (port_number));
169 
170 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
171 			       QT2_GET_SET_UART, 0x40,
172 			       divisor, index, NULL, 0, QT2_USB_TIMEOUT);
173 }
174 
175 static inline int qt2_control_msg(struct usb_device *dev,
176 				  u8 request, u16 data, u16 index)
177 {
178 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
179 			       request, 0x40, data, index,
180 			       NULL, 0, QT2_USB_TIMEOUT);
181 }
182 
183 static inline int qt2_setdevice(struct usb_device *dev, u8 *data)
184 {
185 	u16 x = ((u16) (data[1] << 8) | (u16) (data[0]));
186 
187 	return qt2_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
188 }
189 
190 
191 static inline int qt2_getdevice(struct usb_device *dev, u8 *data)
192 {
193 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
194 			       QT_SET_GET_DEVICE, 0xc0, 0, 0,
195 			       data, 3, QT2_USB_TIMEOUT);
196 }
197 
198 static inline int qt2_getregister(struct usb_device *dev,
199 				  u8 uart,
200 				  u8 reg,
201 				  u8 *data)
202 {
203 	return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
204 			       QT_SET_GET_REGISTER, 0xc0, reg,
205 			       uart, data, sizeof(*data), QT2_USB_TIMEOUT);
206 
207 }
208 
209 static inline int qt2_setregister(struct usb_device *dev,
210 				  u8 uart, u8 reg, u16 data)
211 {
212 	u16 value = (data << 8) | reg;
213 
214 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
215 			       QT_SET_GET_REGISTER, 0x40, value, uart,
216 			       NULL, 0, QT2_USB_TIMEOUT);
217 }
218 
219 static inline int update_mctrl(struct qt2_port_private *port_priv,
220 			       unsigned int set, unsigned int clear)
221 {
222 	struct usb_serial_port *port = port_priv->port;
223 	struct usb_device *dev = port->serial->dev;
224 	unsigned urb_value;
225 	int status;
226 
227 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
228 		dev_dbg(&port->dev,
229 			"update_mctrl - DTR|RTS not being set|cleared\n");
230 		return 0;	/* no change */
231 	}
232 
233 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
234 	urb_value = 0;
235 	if (set & TIOCM_DTR)
236 		urb_value |= UART_MCR_DTR;
237 	if (set & TIOCM_RTS)
238 		urb_value |= UART_MCR_RTS;
239 
240 	status = qt2_setregister(dev, port_priv->device_port, UART_MCR,
241 				 urb_value);
242 	if (status < 0)
243 		dev_err(&port->dev,
244 			"update_mctrl - Error from MODEM_CTRL urb: %i\n",
245 			status);
246 	return status;
247 }
248 
249 static int qt2_calc_num_ports(struct usb_serial *serial)
250 {
251 	struct qt2_device_detail d;
252 	int i;
253 
254 	for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) {
255 		if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct))
256 			return d.num_ports;
257 	}
258 
259 	/* we didn't recognize the device */
260 	dev_err(&serial->dev->dev,
261 		 "don't know the number of ports, assuming 1\n");
262 
263 	return 1;
264 }
265 
266 static void qt2_set_termios(struct tty_struct *tty,
267 			    struct usb_serial_port *port,
268 			    struct ktermios *old_termios)
269 {
270 	struct usb_device *dev = port->serial->dev;
271 	struct qt2_port_private *port_priv;
272 	struct ktermios *termios = &tty->termios;
273 	u16 baud;
274 	unsigned int cflag = termios->c_cflag;
275 	u16 new_lcr = 0;
276 	int status;
277 
278 	port_priv = usb_get_serial_port_data(port);
279 
280 	if (cflag & PARENB) {
281 		if (cflag & PARODD)
282 			new_lcr |= UART_LCR_PARITY;
283 		else
284 			new_lcr |= SERIAL_EVEN_PARITY;
285 	}
286 
287 	switch (cflag & CSIZE) {
288 	case CS5:
289 		new_lcr |= UART_LCR_WLEN5;
290 		break;
291 	case CS6:
292 		new_lcr |= UART_LCR_WLEN6;
293 		break;
294 	case CS7:
295 		new_lcr |= UART_LCR_WLEN7;
296 		break;
297 	default:
298 	case CS8:
299 		new_lcr |= UART_LCR_WLEN8;
300 		break;
301 	}
302 
303 	baud = tty_get_baud_rate(tty);
304 	if (!baud)
305 		baud = 9600;
306 
307 	status = qt2_set_port_config(dev, port_priv->device_port, baud,
308 				     new_lcr);
309 	if (status < 0)
310 		dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
311 			__func__, status);
312 
313 	if (cflag & CRTSCTS)
314 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
315 					 SERIAL_CRTSCTS,
316 					 port_priv->device_port);
317 	else
318 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
319 					 0, port_priv->device_port);
320 	if (status < 0)
321 		dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
322 			__func__, status);
323 
324 	if (I_IXOFF(tty) || I_IXON(tty)) {
325 		u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
326 
327 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
328 					 x, port_priv->device_port);
329 	} else
330 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
331 					 0, port_priv->device_port);
332 
333 	if (status < 0)
334 		dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
335 			__func__, status);
336 
337 }
338 
339 static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
340 {
341 	struct usb_serial *serial;
342 	struct qt2_port_private *port_priv;
343 	u8 *data;
344 	u16 device_port;
345 	int status;
346 	unsigned long flags;
347 
348 	device_port = port->port_number;
349 
350 	serial = port->serial;
351 
352 	port_priv = usb_get_serial_port_data(port);
353 
354 	/* set the port to RS232 mode */
355 	status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
356 				 QT2_QMCR_RS232, device_port);
357 	if (status < 0) {
358 		dev_err(&port->dev,
359 			"%s failed to set RS232 mode for port %i error %i\n",
360 			__func__, device_port, status);
361 		return status;
362 	}
363 
364 	data = kzalloc(2, GFP_KERNEL);
365 	if (!data)
366 		return -ENOMEM;
367 
368 	/* open the port */
369 	status = usb_control_msg(serial->dev,
370 				 usb_rcvctrlpipe(serial->dev, 0),
371 				 QT_OPEN_CLOSE_CHANNEL,
372 				 0xc0, 0,
373 				 device_port, data, 2, QT2_USB_TIMEOUT);
374 
375 	if (status < 0) {
376 		dev_err(&port->dev, "%s - open port failed %i\n", __func__,
377 			status);
378 		kfree(data);
379 		return status;
380 	}
381 
382 	spin_lock_irqsave(&port_priv->lock, flags);
383 	port_priv->shadowLSR = data[0];
384 	port_priv->shadowMSR = data[1];
385 	spin_unlock_irqrestore(&port_priv->lock, flags);
386 
387 	kfree(data);
388 
389 	/* set to default speed and 8bit word size */
390 	status = qt2_set_port_config(serial->dev, device_port,
391 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
392 	if (status < 0) {
393 		dev_err(&port->dev, "%s - initial setup failed (%i)\n",
394 			__func__, device_port);
395 		return status;
396 	}
397 
398 	port_priv->device_port = (u8) device_port;
399 
400 	if (tty)
401 		qt2_set_termios(tty, port, &tty->termios);
402 
403 	return 0;
404 
405 }
406 
407 static void qt2_close(struct usb_serial_port *port)
408 {
409 	struct usb_serial *serial;
410 	struct qt2_port_private *port_priv;
411 	unsigned long flags;
412 	int i;
413 
414 	serial = port->serial;
415 	port_priv = usb_get_serial_port_data(port);
416 
417 	spin_lock_irqsave(&port_priv->urb_lock, flags);
418 	usb_kill_urb(port_priv->write_urb);
419 	port_priv->urb_in_use = false;
420 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
421 
422 	/* flush the port transmit buffer */
423 	i = usb_control_msg(serial->dev,
424 			    usb_rcvctrlpipe(serial->dev, 0),
425 			    QT2_FLUSH_DEVICE, 0x40, 1,
426 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
427 
428 	if (i < 0)
429 		dev_err(&port->dev, "%s - transmit buffer flush failed: %i\n",
430 			__func__, i);
431 
432 	/* flush the port receive buffer */
433 	i = usb_control_msg(serial->dev,
434 			    usb_rcvctrlpipe(serial->dev, 0),
435 			    QT2_FLUSH_DEVICE, 0x40, 0,
436 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
437 
438 	if (i < 0)
439 		dev_err(&port->dev, "%s - receive buffer flush failed: %i\n",
440 			__func__, i);
441 
442 	/* close the port */
443 	i = usb_control_msg(serial->dev,
444 			    usb_sndctrlpipe(serial->dev, 0),
445 			    QT_OPEN_CLOSE_CHANNEL,
446 			    0x40, 0,
447 			    port_priv->device_port, NULL, 0, QT2_USB_TIMEOUT);
448 
449 	if (i < 0)
450 		dev_err(&port->dev, "%s - close port failed %i\n",
451 			__func__, i);
452 }
453 
454 static void qt2_disconnect(struct usb_serial *serial)
455 {
456 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
457 
458 	usb_kill_urb(serial_priv->read_urb);
459 }
460 
461 static int get_serial_info(struct usb_serial_port *port,
462 			   struct serial_struct __user *retinfo)
463 {
464 	struct serial_struct tmp;
465 
466 	memset(&tmp, 0, sizeof(tmp));
467 	tmp.line		= port->minor;
468 	tmp.port		= 0;
469 	tmp.irq			= 0;
470 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
471 	tmp.xmit_fifo_size	= port->bulk_out_size;
472 	tmp.baud_base		= 9600;
473 	tmp.close_delay		= 5*HZ;
474 	tmp.closing_wait	= 30*HZ;
475 
476 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
477 		return -EFAULT;
478 	return 0;
479 }
480 
481 static int qt2_ioctl(struct tty_struct *tty,
482 		     unsigned int cmd, unsigned long arg)
483 {
484 	struct usb_serial_port *port = tty->driver_data;
485 
486 	switch (cmd) {
487 	case TIOCGSERIAL:
488 		return get_serial_info(port,
489 				       (struct serial_struct __user *)arg);
490 	default:
491 		break;
492 	}
493 
494 	return -ENOIOCTLCMD;
495 }
496 
497 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
498 {
499 	switch (*ch) {
500 	case QT2_LINE_STATUS:
501 		qt2_update_lsr(port, ch + 1);
502 		break;
503 	case QT2_MODEM_STATUS:
504 		qt2_update_msr(port, ch + 1);
505 		break;
506 	}
507 }
508 
509 /* not needed, kept to document functionality */
510 static void qt2_process_xmit_empty(struct usb_serial_port *port,
511 				   unsigned char *ch)
512 {
513 	int bytes_written;
514 
515 	bytes_written = (int)(*ch) + (int)(*(ch + 1) << 4);
516 }
517 
518 /* not needed, kept to document functionality */
519 static void qt2_process_flush(struct usb_serial_port *port, unsigned char *ch)
520 {
521 	return;
522 }
523 
524 static void qt2_process_read_urb(struct urb *urb)
525 {
526 	struct usb_serial *serial;
527 	struct qt2_serial_private *serial_priv;
528 	struct usb_serial_port *port;
529 	struct qt2_port_private *port_priv;
530 	bool escapeflag;
531 	unsigned char *ch;
532 	int i;
533 	unsigned char newport;
534 	int len = urb->actual_length;
535 
536 	if (!len)
537 		return;
538 
539 	ch = urb->transfer_buffer;
540 	serial = urb->context;
541 	serial_priv = usb_get_serial_data(serial);
542 	port = serial->port[serial_priv->current_port];
543 	port_priv = usb_get_serial_port_data(port);
544 
545 	for (i = 0; i < urb->actual_length; i++) {
546 		ch = (unsigned char *)urb->transfer_buffer + i;
547 		if ((i <= (len - 3)) &&
548 		    (*ch == QT2_CONTROL_BYTE) &&
549 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
550 			escapeflag = false;
551 			switch (*(ch + 2)) {
552 			case QT2_LINE_STATUS:
553 			case QT2_MODEM_STATUS:
554 				if (i > (len - 4)) {
555 					dev_warn(&port->dev,
556 						 "%s - status message too short\n",
557 						__func__);
558 					break;
559 				}
560 				qt2_process_status(port, ch + 2);
561 				i += 3;
562 				escapeflag = true;
563 				break;
564 			case QT2_XMIT_HOLD:
565 				if (i > (len - 5)) {
566 					dev_warn(&port->dev,
567 						 "%s - xmit_empty message too short\n",
568 						 __func__);
569 					break;
570 				}
571 				qt2_process_xmit_empty(port, ch + 3);
572 				i += 4;
573 				escapeflag = true;
574 				break;
575 			case QT2_CHANGE_PORT:
576 				if (i > (len - 4)) {
577 					dev_warn(&port->dev,
578 						 "%s - change_port message too short\n",
579 						 __func__);
580 					break;
581 				}
582 				tty_flip_buffer_push(&port->port);
583 
584 				newport = *(ch + 3);
585 
586 				if (newport > serial->num_ports) {
587 					dev_err(&port->dev,
588 						"%s - port change to invalid port: %i\n",
589 						__func__, newport);
590 					break;
591 				}
592 
593 				serial_priv->current_port = newport;
594 				port = serial->port[serial_priv->current_port];
595 				port_priv = usb_get_serial_port_data(port);
596 				i += 3;
597 				escapeflag = true;
598 				break;
599 			case QT2_REC_FLUSH:
600 			case QT2_XMIT_FLUSH:
601 				qt2_process_flush(port, ch + 2);
602 				i += 2;
603 				escapeflag = true;
604 				break;
605 			case QT2_CONTROL_ESCAPE:
606 				tty_buffer_request_room(&port->port, 2);
607 				tty_insert_flip_string(&port->port, ch, 2);
608 				i += 2;
609 				escapeflag = true;
610 				break;
611 			default:
612 				dev_warn(&port->dev,
613 					 "%s - unsupported command %i\n",
614 					 __func__, *(ch + 2));
615 				break;
616 			}
617 			if (escapeflag)
618 				continue;
619 		}
620 
621 		tty_buffer_request_room(&port->port, 1);
622 		tty_insert_flip_string(&port->port, ch, 1);
623 	}
624 
625 	tty_flip_buffer_push(&port->port);
626 }
627 
628 static void qt2_write_bulk_callback(struct urb *urb)
629 {
630 	struct usb_serial_port *port;
631 	struct qt2_port_private *port_priv;
632 
633 	port = urb->context;
634 	port_priv = usb_get_serial_port_data(port);
635 
636 	spin_lock(&port_priv->urb_lock);
637 
638 	port_priv->urb_in_use = false;
639 	usb_serial_port_softint(port);
640 
641 	spin_unlock(&port_priv->urb_lock);
642 
643 }
644 
645 static void qt2_read_bulk_callback(struct urb *urb)
646 {
647 	struct usb_serial *serial = urb->context;
648 	int status;
649 
650 	if (urb->status) {
651 		dev_warn(&serial->dev->dev,
652 			 "%s - non-zero urb status: %i\n", __func__,
653 			 urb->status);
654 		return;
655 	}
656 
657 	qt2_process_read_urb(urb);
658 
659 	status = usb_submit_urb(urb, GFP_ATOMIC);
660 	if (status != 0)
661 		dev_err(&serial->dev->dev,
662 			"%s - resubmit read urb failed: %i\n",
663 			__func__, status);
664 }
665 
666 static int qt2_setup_urbs(struct usb_serial *serial)
667 {
668 	struct usb_serial_port *port0;
669 	struct qt2_serial_private *serial_priv;
670 	int status;
671 
672 	port0 = serial->port[0];
673 
674 	serial_priv = usb_get_serial_data(serial);
675 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
676 	if (!serial_priv->read_urb)
677 		return -ENOMEM;
678 
679 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
680 			  usb_rcvbulkpipe(serial->dev,
681 					  port0->bulk_in_endpointAddress),
682 			  serial_priv->read_buffer,
683 			  QT2_READ_BUFFER_SIZE,
684 			  qt2_read_bulk_callback, serial);
685 
686 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
687 	if (status != 0) {
688 		dev_err(&serial->dev->dev,
689 			"%s - submit read urb failed %i\n", __func__, status);
690 		usb_free_urb(serial_priv->read_urb);
691 		return status;
692 	}
693 
694 	return 0;
695 }
696 
697 static int qt2_attach(struct usb_serial *serial)
698 {
699 	struct qt2_serial_private *serial_priv;
700 	int status;
701 
702 	/* power on unit */
703 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
704 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
705 				 QT2_USB_TIMEOUT);
706 	if (status < 0) {
707 		dev_err(&serial->dev->dev,
708 			"%s - failed to power on unit: %i\n", __func__, status);
709 		return status;
710 	}
711 
712 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
713 	if (!serial_priv)
714 		return -ENOMEM;
715 
716 	serial_priv->read_buffer = kmalloc(QT2_READ_BUFFER_SIZE, GFP_KERNEL);
717 	if (!serial_priv->read_buffer) {
718 		status = -ENOMEM;
719 		goto err_buf;
720 	}
721 
722 	usb_set_serial_data(serial, serial_priv);
723 
724 	status = qt2_setup_urbs(serial);
725 	if (status != 0)
726 		goto attach_failed;
727 
728 	return 0;
729 
730 attach_failed:
731 	kfree(serial_priv->read_buffer);
732 err_buf:
733 	kfree(serial_priv);
734 	return status;
735 }
736 
737 static int qt2_port_probe(struct usb_serial_port *port)
738 {
739 	struct usb_serial *serial = port->serial;
740 	struct qt2_port_private *port_priv;
741 	u8 bEndpointAddress;
742 
743 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
744 	if (!port_priv)
745 		return -ENOMEM;
746 
747 	spin_lock_init(&port_priv->lock);
748 	spin_lock_init(&port_priv->urb_lock);
749 	port_priv->port = port;
750 
751 	port_priv->write_buffer = kmalloc(QT2_WRITE_BUFFER_SIZE, GFP_KERNEL);
752 	if (!port_priv->write_buffer)
753 		goto err_buf;
754 
755 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
756 	if (!port_priv->write_urb)
757 		goto err_urb;
758 
759 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
760 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
761 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
762 				port_priv->write_buffer,
763 				QT2_WRITE_BUFFER_SIZE,
764 				qt2_write_bulk_callback, port);
765 
766 	usb_set_serial_port_data(port, port_priv);
767 
768 	return 0;
769 err_urb:
770 	kfree(port_priv->write_buffer);
771 err_buf:
772 	kfree(port_priv);
773 	return -ENOMEM;
774 }
775 
776 static int qt2_port_remove(struct usb_serial_port *port)
777 {
778 	struct qt2_port_private *port_priv;
779 
780 	port_priv = usb_get_serial_port_data(port);
781 	usb_free_urb(port_priv->write_urb);
782 	kfree(port_priv->write_buffer);
783 	kfree(port_priv);
784 
785 	return 0;
786 }
787 
788 static int qt2_tiocmget(struct tty_struct *tty)
789 {
790 	struct usb_serial_port *port = tty->driver_data;
791 	struct usb_device *dev = port->serial->dev;
792 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
793 	u8 *d;
794 	int r;
795 
796 	d = kzalloc(2, GFP_KERNEL);
797 	if (!d)
798 		return -ENOMEM;
799 
800 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
801 	if (r < 0)
802 		goto mget_out;
803 
804 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
805 	if (r < 0)
806 		goto mget_out;
807 
808 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
809 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
810 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
811 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
812 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
813 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
814 
815 mget_out:
816 	kfree(d);
817 	return r;
818 }
819 
820 static int qt2_tiocmset(struct tty_struct *tty,
821 			unsigned int set, unsigned int clear)
822 {
823 	struct qt2_port_private *port_priv;
824 
825 	port_priv = usb_get_serial_port_data(tty->driver_data);
826 	return update_mctrl(port_priv, set, clear);
827 }
828 
829 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
830 {
831 	struct usb_serial_port *port = tty->driver_data;
832 	struct qt2_port_private *port_priv;
833 	int status;
834 	u16 val;
835 
836 	port_priv = usb_get_serial_port_data(port);
837 
838 	val = (break_state == -1) ? 1 : 0;
839 
840 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
841 				 val, port_priv->device_port);
842 	if (status < 0)
843 		dev_warn(&port->dev,
844 			 "%s - failed to send control message: %i\n", __func__,
845 			 status);
846 }
847 
848 
849 
850 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
851 {
852 	struct usb_device *dev = port->serial->dev;
853 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
854 
855 	/* Disable flow control */
856 	if (!on) {
857 		if (qt2_setregister(dev, port_priv->device_port,
858 					   UART_MCR, 0) < 0)
859 			dev_warn(&port->dev, "error from flowcontrol urb\n");
860 	}
861 	/* drop RTS and DTR */
862 	if (on)
863 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
864 	else
865 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
866 }
867 
868 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
869 {
870 	struct qt2_port_private *port_priv;
871 	u8 newMSR = (u8) *ch;
872 	unsigned long flags;
873 
874 	port_priv = usb_get_serial_port_data(port);
875 
876 	spin_lock_irqsave(&port_priv->lock, flags);
877 	port_priv->shadowMSR = newMSR;
878 	spin_unlock_irqrestore(&port_priv->lock, flags);
879 
880 	if (newMSR & UART_MSR_ANY_DELTA) {
881 		/* update input line counters */
882 		if (newMSR & UART_MSR_DCTS)
883 			port->icount.cts++;
884 		if (newMSR & UART_MSR_DDSR)
885 			port->icount.dsr++;
886 		if (newMSR & UART_MSR_DDCD)
887 			port->icount.dcd++;
888 		if (newMSR & UART_MSR_TERI)
889 			port->icount.rng++;
890 
891 		wake_up_interruptible(&port->port.delta_msr_wait);
892 	}
893 }
894 
895 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
896 {
897 	struct qt2_port_private *port_priv;
898 	struct async_icount *icount;
899 	unsigned long flags;
900 	u8 newLSR = (u8) *ch;
901 
902 	port_priv = usb_get_serial_port_data(port);
903 
904 	if (newLSR & UART_LSR_BI)
905 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
906 
907 	spin_lock_irqsave(&port_priv->lock, flags);
908 	port_priv->shadowLSR = newLSR;
909 	spin_unlock_irqrestore(&port_priv->lock, flags);
910 
911 	icount = &port->icount;
912 
913 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
914 
915 		if (newLSR & UART_LSR_BI)
916 			icount->brk++;
917 
918 		if (newLSR & UART_LSR_OE)
919 			icount->overrun++;
920 
921 		if (newLSR & UART_LSR_PE)
922 			icount->parity++;
923 
924 		if (newLSR & UART_LSR_FE)
925 			icount->frame++;
926 	}
927 
928 }
929 
930 static int qt2_write_room(struct tty_struct *tty)
931 {
932 	struct usb_serial_port *port = tty->driver_data;
933 	struct qt2_port_private *port_priv;
934 	unsigned long flags = 0;
935 	int r;
936 
937 	port_priv = usb_get_serial_port_data(port);
938 
939 	spin_lock_irqsave(&port_priv->urb_lock, flags);
940 
941 	if (port_priv->urb_in_use)
942 		r = 0;
943 	else
944 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
945 
946 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
947 
948 	return r;
949 }
950 
951 static int qt2_write(struct tty_struct *tty,
952 		     struct usb_serial_port *port,
953 		     const unsigned char *buf, int count)
954 {
955 	struct qt2_port_private *port_priv;
956 	struct urb *write_urb;
957 	unsigned char *data;
958 	unsigned long flags;
959 	int status;
960 	int bytes_out = 0;
961 
962 	port_priv = usb_get_serial_port_data(port);
963 
964 	if (port_priv->write_urb == NULL) {
965 		dev_err(&port->dev, "%s - no output urb\n", __func__);
966 		return 0;
967 	}
968 	write_urb = port_priv->write_urb;
969 
970 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
971 
972 	data = write_urb->transfer_buffer;
973 	spin_lock_irqsave(&port_priv->urb_lock, flags);
974 	if (port_priv->urb_in_use) {
975 		dev_err(&port->dev, "qt2_write - urb is in use\n");
976 		goto write_out;
977 	}
978 
979 	*data++ = QT2_CONTROL_BYTE;
980 	*data++ = QT2_CONTROL_BYTE;
981 	*data++ = port_priv->device_port;
982 	put_unaligned_le16(count, data);
983 	data += 2;
984 	memcpy(data, buf, count);
985 
986 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
987 
988 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
989 	if (status == 0) {
990 		port_priv->urb_in_use = true;
991 		bytes_out += count;
992 	}
993 
994 write_out:
995 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
996 	return bytes_out;
997 }
998 
999 
1000 static struct usb_serial_driver qt2_device = {
1001 	.driver = {
1002 		.owner = THIS_MODULE,
1003 		.name = "quatech-serial",
1004 	},
1005 	.description	     = DRIVER_DESC,
1006 	.id_table	     = id_table,
1007 	.open		     = qt2_open,
1008 	.close		     = qt2_close,
1009 	.write               = qt2_write,
1010 	.write_room          = qt2_write_room,
1011 	.calc_num_ports      = qt2_calc_num_ports,
1012 	.attach              = qt2_attach,
1013 	.release             = qt2_release,
1014 	.disconnect          = qt2_disconnect,
1015 	.port_probe          = qt2_port_probe,
1016 	.port_remove         = qt2_port_remove,
1017 	.dtr_rts             = qt2_dtr_rts,
1018 	.break_ctl           = qt2_break_ctl,
1019 	.tiocmget            = qt2_tiocmget,
1020 	.tiocmset            = qt2_tiocmset,
1021 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
1022 	.get_icount	     = usb_serial_generic_get_icount,
1023 	.ioctl               = qt2_ioctl,
1024 	.set_termios         = qt2_set_termios,
1025 };
1026 
1027 static struct usb_serial_driver *const serial_drivers[] = {
1028 	&qt2_device, NULL
1029 };
1030 
1031 module_usb_serial_driver(serial_drivers, id_table);
1032 
1033 MODULE_DESCRIPTION(DRIVER_DESC);
1034 MODULE_LICENSE("GPL");
1035