xref: /linux/drivers/usb/serial/quatech2.c (revision 5fd54ace4721fc5ce2bb5aef6318fcf17f421460)
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  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License version 2
9  * as published by the Free Software Foundation.
10  *
11  *
12  *  These devices all have only 1 bulk in and 1 bulk out that is shared
13  *  for all serial ports.
14  *
15  */
16 
17 #include <asm/unaligned.h>
18 #include <linux/errno.h>
19 #include <linux/slab.h>
20 #include <linux/tty.h>
21 #include <linux/tty_driver.h>
22 #include <linux/tty_flip.h>
23 #include <linux/module.h>
24 #include <linux/serial.h>
25 #include <linux/usb.h>
26 #include <linux/usb/serial.h>
27 #include <linux/serial_reg.h>
28 #include <linux/uaccess.h>
29 
30 /* default urb timeout for usb operations */
31 #define QT2_USB_TIMEOUT USB_CTRL_SET_TIMEOUT
32 
33 #define QT_OPEN_CLOSE_CHANNEL       0xca
34 #define QT_SET_GET_DEVICE           0xc2
35 #define QT_SET_GET_REGISTER         0xc0
36 #define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
37 #define QT_SET_ATF                  0xcd
38 #define QT_TRANSFER_IN              0xc0
39 #define QT_HW_FLOW_CONTROL_MASK     0xc5
40 #define QT_SW_FLOW_CONTROL_MASK     0xc6
41 #define QT2_BREAK_CONTROL	    0xc8
42 #define QT2_GET_SET_UART            0xc1
43 #define QT2_FLUSH_DEVICE	    0xc4
44 #define QT2_GET_SET_QMCR            0xe1
45 #define QT2_QMCR_RS232              0x40
46 #define QT2_QMCR_RS422              0x10
47 
48 #define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
49 
50 #define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
51 
52 /* status bytes for the device */
53 #define QT2_CONTROL_BYTE    0x1b
54 #define QT2_LINE_STATUS     0x00  /* following 1 byte is line status */
55 #define QT2_MODEM_STATUS    0x01  /* following 1 byte is modem status */
56 #define QT2_XMIT_HOLD       0x02  /* following 2 bytes are ?? */
57 #define QT2_CHANGE_PORT     0x03  /* following 1 byte is port to change to */
58 #define QT2_REC_FLUSH       0x04  /* no following info */
59 #define QT2_XMIT_FLUSH      0x05  /* no following info */
60 #define QT2_CONTROL_ESCAPE  0xff  /* pass through previous 2 control bytes */
61 
62 #define  MAX_BAUD_RATE              921600
63 #define  DEFAULT_BAUD_RATE          9600
64 
65 #define QT2_READ_BUFFER_SIZE    512  /* size of read buffer */
66 #define QT2_WRITE_BUFFER_SIZE   512  /* size of write buffer */
67 #define QT2_WRITE_CONTROL_SIZE  5    /* control bytes used for a write */
68 
69 #define DRIVER_DESC "Quatech 2nd gen USB to Serial Driver"
70 
71 #define	USB_VENDOR_ID_QUATECH	0x061d
72 #define QUATECH_SSU2_100	0xC120	/* RS232 single port */
73 #define QUATECH_DSU2_100	0xC140	/* RS232 dual port */
74 #define QUATECH_DSU2_400	0xC150	/* RS232/422/485 dual port */
75 #define QUATECH_QSU2_100	0xC160	/* RS232 four port */
76 #define QUATECH_QSU2_400	0xC170	/* RS232/422/485 four port */
77 #define QUATECH_ESU2_100	0xC1A0	/* RS232 eight port */
78 #define QUATECH_ESU2_400	0xC180	/* RS232/422/485 eight port */
79 
80 struct qt2_device_detail {
81 	int product_id;
82 	int num_ports;
83 };
84 
85 #define QT_DETAILS(prod, ports)	\
86 	.product_id = (prod),   \
87 	.num_ports = (ports)
88 
89 static const struct qt2_device_detail qt2_device_details[] = {
90 	{QT_DETAILS(QUATECH_SSU2_100, 1)},
91 	{QT_DETAILS(QUATECH_DSU2_400, 2)},
92 	{QT_DETAILS(QUATECH_DSU2_100, 2)},
93 	{QT_DETAILS(QUATECH_QSU2_400, 4)},
94 	{QT_DETAILS(QUATECH_QSU2_100, 4)},
95 	{QT_DETAILS(QUATECH_ESU2_400, 8)},
96 	{QT_DETAILS(QUATECH_ESU2_100, 8)},
97 	{QT_DETAILS(0, 0)}	/* Terminating entry */
98 };
99 
100 static const struct usb_device_id id_table[] = {
101 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU2_100)},
102 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_100)},
103 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_DSU2_400)},
104 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_100)},
105 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_QSU2_400)},
106 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_100)},
107 	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_ESU2_400)},
108 	{}			/* Terminating entry */
109 };
110 MODULE_DEVICE_TABLE(usb, id_table);
111 
112 struct qt2_serial_private {
113 	unsigned char current_port;  /* current port for incoming data */
114 
115 	struct urb	*read_urb;   /* shared among all ports */
116 	char		*read_buffer;
117 };
118 
119 struct qt2_port_private {
120 	u8   device_port;
121 
122 	spinlock_t urb_lock;
123 	bool       urb_in_use;
124 	struct urb *write_urb;
125 	char       *write_buffer;
126 
127 	spinlock_t  lock;
128 	u8          shadowLSR;
129 	u8          shadowMSR;
130 
131 	struct usb_serial_port *port;
132 };
133 
134 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch);
135 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch);
136 static void qt2_write_bulk_callback(struct urb *urb);
137 static void qt2_read_bulk_callback(struct urb *urb);
138 
139 static void qt2_release(struct usb_serial *serial)
140 {
141 	struct qt2_serial_private *serial_priv;
142 
143 	serial_priv = usb_get_serial_data(serial);
144 
145 	usb_kill_urb(serial_priv->read_urb);
146 	usb_free_urb(serial_priv->read_urb);
147 	kfree(serial_priv->read_buffer);
148 	kfree(serial_priv);
149 }
150 
151 static inline int calc_baud_divisor(int baudrate)
152 {
153 	int divisor, rem;
154 
155 	divisor = MAX_BAUD_RATE / baudrate;
156 	rem = MAX_BAUD_RATE % baudrate;
157 	/* Round to nearest divisor */
158 	if (((rem * 2) >= baudrate) && (baudrate != 110))
159 		divisor++;
160 
161 	return divisor;
162 }
163 
164 static inline int qt2_set_port_config(struct usb_device *dev,
165 				      unsigned char port_number,
166 				      u16 baudrate, u16 lcr)
167 {
168 	int divisor = calc_baud_divisor(baudrate);
169 	u16 index = ((u16) (lcr << 8) | (u16) (port_number));
170 
171 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
172 			       QT2_GET_SET_UART, 0x40,
173 			       divisor, index, NULL, 0, QT2_USB_TIMEOUT);
174 }
175 
176 static inline int qt2_control_msg(struct usb_device *dev,
177 				  u8 request, u16 data, u16 index)
178 {
179 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
180 			       request, 0x40, data, index,
181 			       NULL, 0, QT2_USB_TIMEOUT);
182 }
183 
184 static inline int qt2_setdevice(struct usb_device *dev, u8 *data)
185 {
186 	u16 x = ((u16) (data[1] << 8) | (u16) (data[0]));
187 
188 	return qt2_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
189 }
190 
191 
192 static inline int qt2_getregister(struct usb_device *dev,
193 				  u8 uart,
194 				  u8 reg,
195 				  u8 *data)
196 {
197 	int ret;
198 
199 	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
200 			      QT_SET_GET_REGISTER, 0xc0, reg,
201 			      uart, data, sizeof(*data), QT2_USB_TIMEOUT);
202 	if (ret < sizeof(*data)) {
203 		if (ret >= 0)
204 			ret = -EIO;
205 	}
206 
207 	return ret;
208 }
209 
210 static inline int qt2_setregister(struct usb_device *dev,
211 				  u8 uart, u8 reg, u16 data)
212 {
213 	u16 value = (data << 8) | reg;
214 
215 	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
216 			       QT_SET_GET_REGISTER, 0x40, value, uart,
217 			       NULL, 0, QT2_USB_TIMEOUT);
218 }
219 
220 static inline int update_mctrl(struct qt2_port_private *port_priv,
221 			       unsigned int set, unsigned int clear)
222 {
223 	struct usb_serial_port *port = port_priv->port;
224 	struct usb_device *dev = port->serial->dev;
225 	unsigned urb_value;
226 	int status;
227 
228 	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
229 		dev_dbg(&port->dev,
230 			"update_mctrl - DTR|RTS not being set|cleared\n");
231 		return 0;	/* no change */
232 	}
233 
234 	clear &= ~set;	/* 'set' takes precedence over 'clear' */
235 	urb_value = 0;
236 	if (set & TIOCM_DTR)
237 		urb_value |= UART_MCR_DTR;
238 	if (set & TIOCM_RTS)
239 		urb_value |= UART_MCR_RTS;
240 
241 	status = qt2_setregister(dev, port_priv->device_port, UART_MCR,
242 				 urb_value);
243 	if (status < 0)
244 		dev_err(&port->dev,
245 			"update_mctrl - Error from MODEM_CTRL urb: %i\n",
246 			status);
247 	return status;
248 }
249 
250 static int qt2_calc_num_ports(struct usb_serial *serial,
251 					struct usb_serial_endpoints *epds)
252 {
253 	struct qt2_device_detail d;
254 	int i;
255 
256 	for (i = 0; d = qt2_device_details[i], d.product_id != 0; i++) {
257 		if (d.product_id == le16_to_cpu(serial->dev->descriptor.idProduct))
258 			return d.num_ports;
259 	}
260 
261 	/* we didn't recognize the device */
262 	dev_err(&serial->dev->dev,
263 		 "don't know the number of ports, assuming 1\n");
264 
265 	return 1;
266 }
267 
268 static void qt2_set_termios(struct tty_struct *tty,
269 			    struct usb_serial_port *port,
270 			    struct ktermios *old_termios)
271 {
272 	struct usb_device *dev = port->serial->dev;
273 	struct qt2_port_private *port_priv;
274 	struct ktermios *termios = &tty->termios;
275 	u16 baud;
276 	unsigned int cflag = termios->c_cflag;
277 	u16 new_lcr = 0;
278 	int status;
279 
280 	port_priv = usb_get_serial_port_data(port);
281 
282 	if (cflag & PARENB) {
283 		if (cflag & PARODD)
284 			new_lcr |= UART_LCR_PARITY;
285 		else
286 			new_lcr |= SERIAL_EVEN_PARITY;
287 	}
288 
289 	switch (cflag & CSIZE) {
290 	case CS5:
291 		new_lcr |= UART_LCR_WLEN5;
292 		break;
293 	case CS6:
294 		new_lcr |= UART_LCR_WLEN6;
295 		break;
296 	case CS7:
297 		new_lcr |= UART_LCR_WLEN7;
298 		break;
299 	default:
300 	case CS8:
301 		new_lcr |= UART_LCR_WLEN8;
302 		break;
303 	}
304 
305 	baud = tty_get_baud_rate(tty);
306 	if (!baud)
307 		baud = 9600;
308 
309 	status = qt2_set_port_config(dev, port_priv->device_port, baud,
310 				     new_lcr);
311 	if (status < 0)
312 		dev_err(&port->dev, "%s - qt2_set_port_config failed: %i\n",
313 			__func__, status);
314 
315 	if (cflag & CRTSCTS)
316 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
317 					 SERIAL_CRTSCTS,
318 					 port_priv->device_port);
319 	else
320 		status = qt2_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
321 					 0, port_priv->device_port);
322 	if (status < 0)
323 		dev_err(&port->dev, "%s - set HW flow control failed: %i\n",
324 			__func__, status);
325 
326 	if (I_IXOFF(tty) || I_IXON(tty)) {
327 		u16 x = ((u16) (START_CHAR(tty) << 8) | (u16) (STOP_CHAR(tty)));
328 
329 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
330 					 x, port_priv->device_port);
331 	} else
332 		status = qt2_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
333 					 0, port_priv->device_port);
334 
335 	if (status < 0)
336 		dev_err(&port->dev, "%s - set SW flow control failed: %i\n",
337 			__func__, status);
338 
339 }
340 
341 static int qt2_open(struct tty_struct *tty, struct usb_serial_port *port)
342 {
343 	struct usb_serial *serial;
344 	struct qt2_port_private *port_priv;
345 	u8 *data;
346 	u16 device_port;
347 	int status;
348 	unsigned long flags;
349 
350 	device_port = port->port_number;
351 
352 	serial = port->serial;
353 
354 	port_priv = usb_get_serial_port_data(port);
355 
356 	/* set the port to RS232 mode */
357 	status = qt2_control_msg(serial->dev, QT2_GET_SET_QMCR,
358 				 QT2_QMCR_RS232, device_port);
359 	if (status < 0) {
360 		dev_err(&port->dev,
361 			"%s failed to set RS232 mode for port %i error %i\n",
362 			__func__, device_port, status);
363 		return status;
364 	}
365 
366 	data = kzalloc(2, GFP_KERNEL);
367 	if (!data)
368 		return -ENOMEM;
369 
370 	/* open the port */
371 	status = usb_control_msg(serial->dev,
372 				 usb_rcvctrlpipe(serial->dev, 0),
373 				 QT_OPEN_CLOSE_CHANNEL,
374 				 0xc0, 0,
375 				 device_port, data, 2, QT2_USB_TIMEOUT);
376 
377 	if (status < 2) {
378 		dev_err(&port->dev, "%s - open port failed %i\n", __func__,
379 			status);
380 		if (status >= 0)
381 			status = -EIO;
382 		kfree(data);
383 		return status;
384 	}
385 
386 	spin_lock_irqsave(&port_priv->lock, flags);
387 	port_priv->shadowLSR = data[0];
388 	port_priv->shadowMSR = data[1];
389 	spin_unlock_irqrestore(&port_priv->lock, flags);
390 
391 	kfree(data);
392 
393 	/* set to default speed and 8bit word size */
394 	status = qt2_set_port_config(serial->dev, device_port,
395 				     DEFAULT_BAUD_RATE, UART_LCR_WLEN8);
396 	if (status < 0) {
397 		dev_err(&port->dev, "%s - initial setup failed (%i)\n",
398 			__func__, device_port);
399 		return status;
400 	}
401 
402 	port_priv->device_port = (u8) device_port;
403 
404 	if (tty)
405 		qt2_set_termios(tty, port, &tty->termios);
406 
407 	return 0;
408 
409 }
410 
411 static void qt2_close(struct usb_serial_port *port)
412 {
413 	struct usb_serial *serial;
414 	struct qt2_port_private *port_priv;
415 	int i;
416 
417 	serial = port->serial;
418 	port_priv = usb_get_serial_port_data(port);
419 
420 	usb_kill_urb(port_priv->write_urb);
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.xmit_fifo_size	= port->bulk_out_size;
471 	tmp.baud_base		= 9600;
472 	tmp.close_delay		= 5*HZ;
473 	tmp.closing_wait	= 30*HZ;
474 
475 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
476 		return -EFAULT;
477 	return 0;
478 }
479 
480 static int qt2_ioctl(struct tty_struct *tty,
481 		     unsigned int cmd, unsigned long arg)
482 {
483 	struct usb_serial_port *port = tty->driver_data;
484 
485 	switch (cmd) {
486 	case TIOCGSERIAL:
487 		return get_serial_info(port,
488 				       (struct serial_struct __user *)arg);
489 	default:
490 		break;
491 	}
492 
493 	return -ENOIOCTLCMD;
494 }
495 
496 static void qt2_process_status(struct usb_serial_port *port, unsigned char *ch)
497 {
498 	switch (*ch) {
499 	case QT2_LINE_STATUS:
500 		qt2_update_lsr(port, ch + 1);
501 		break;
502 	case QT2_MODEM_STATUS:
503 		qt2_update_msr(port, ch + 1);
504 		break;
505 	}
506 }
507 
508 /* not needed, kept to document functionality */
509 static void qt2_process_xmit_empty(struct usb_serial_port *port,
510 				   unsigned char *ch)
511 {
512 	int bytes_written;
513 
514 	bytes_written = (int)(*ch) + (int)(*(ch + 1) << 4);
515 }
516 
517 /* not needed, kept to document functionality */
518 static void qt2_process_flush(struct usb_serial_port *port, unsigned char *ch)
519 {
520 	return;
521 }
522 
523 static void qt2_process_read_urb(struct urb *urb)
524 {
525 	struct usb_serial *serial;
526 	struct qt2_serial_private *serial_priv;
527 	struct usb_serial_port *port;
528 	struct qt2_port_private *port_priv;
529 	bool escapeflag;
530 	unsigned char *ch;
531 	int i;
532 	unsigned char newport;
533 	int len = urb->actual_length;
534 
535 	if (!len)
536 		return;
537 
538 	ch = urb->transfer_buffer;
539 	serial = urb->context;
540 	serial_priv = usb_get_serial_data(serial);
541 	port = serial->port[serial_priv->current_port];
542 	port_priv = usb_get_serial_port_data(port);
543 
544 	for (i = 0; i < urb->actual_length; i++) {
545 		ch = (unsigned char *)urb->transfer_buffer + i;
546 		if ((i <= (len - 3)) &&
547 		    (*ch == QT2_CONTROL_BYTE) &&
548 		    (*(ch + 1) == QT2_CONTROL_BYTE)) {
549 			escapeflag = false;
550 			switch (*(ch + 2)) {
551 			case QT2_LINE_STATUS:
552 			case QT2_MODEM_STATUS:
553 				if (i > (len - 4)) {
554 					dev_warn(&port->dev,
555 						 "%s - status message too short\n",
556 						__func__);
557 					break;
558 				}
559 				qt2_process_status(port, ch + 2);
560 				i += 3;
561 				escapeflag = true;
562 				break;
563 			case QT2_XMIT_HOLD:
564 				if (i > (len - 5)) {
565 					dev_warn(&port->dev,
566 						 "%s - xmit_empty message too short\n",
567 						 __func__);
568 					break;
569 				}
570 				qt2_process_xmit_empty(port, ch + 3);
571 				i += 4;
572 				escapeflag = true;
573 				break;
574 			case QT2_CHANGE_PORT:
575 				if (i > (len - 4)) {
576 					dev_warn(&port->dev,
577 						 "%s - change_port message too short\n",
578 						 __func__);
579 					break;
580 				}
581 				tty_flip_buffer_push(&port->port);
582 
583 				newport = *(ch + 3);
584 
585 				if (newport > serial->num_ports) {
586 					dev_err(&port->dev,
587 						"%s - port change to invalid port: %i\n",
588 						__func__, newport);
589 					break;
590 				}
591 
592 				serial_priv->current_port = newport;
593 				port = serial->port[serial_priv->current_port];
594 				port_priv = usb_get_serial_port_data(port);
595 				i += 3;
596 				escapeflag = true;
597 				break;
598 			case QT2_REC_FLUSH:
599 			case QT2_XMIT_FLUSH:
600 				qt2_process_flush(port, ch + 2);
601 				i += 2;
602 				escapeflag = true;
603 				break;
604 			case QT2_CONTROL_ESCAPE:
605 				tty_insert_flip_string(&port->port, ch, 2);
606 				i += 2;
607 				escapeflag = true;
608 				break;
609 			default:
610 				dev_warn(&port->dev,
611 					 "%s - unsupported command %i\n",
612 					 __func__, *(ch + 2));
613 				break;
614 			}
615 			if (escapeflag)
616 				continue;
617 		}
618 
619 		tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
620 	}
621 
622 	tty_flip_buffer_push(&port->port);
623 }
624 
625 static void qt2_write_bulk_callback(struct urb *urb)
626 {
627 	struct usb_serial_port *port;
628 	struct qt2_port_private *port_priv;
629 
630 	port = urb->context;
631 	port_priv = usb_get_serial_port_data(port);
632 
633 	spin_lock(&port_priv->urb_lock);
634 
635 	port_priv->urb_in_use = false;
636 	usb_serial_port_softint(port);
637 
638 	spin_unlock(&port_priv->urb_lock);
639 
640 }
641 
642 static void qt2_read_bulk_callback(struct urb *urb)
643 {
644 	struct usb_serial *serial = urb->context;
645 	int status;
646 
647 	if (urb->status) {
648 		dev_warn(&serial->dev->dev,
649 			 "%s - non-zero urb status: %i\n", __func__,
650 			 urb->status);
651 		return;
652 	}
653 
654 	qt2_process_read_urb(urb);
655 
656 	status = usb_submit_urb(urb, GFP_ATOMIC);
657 	if (status != 0)
658 		dev_err(&serial->dev->dev,
659 			"%s - resubmit read urb failed: %i\n",
660 			__func__, status);
661 }
662 
663 static int qt2_setup_urbs(struct usb_serial *serial)
664 {
665 	struct usb_serial_port *port0;
666 	struct qt2_serial_private *serial_priv;
667 	int status;
668 
669 	port0 = serial->port[0];
670 
671 	serial_priv = usb_get_serial_data(serial);
672 	serial_priv->read_urb = usb_alloc_urb(0, GFP_KERNEL);
673 	if (!serial_priv->read_urb)
674 		return -ENOMEM;
675 
676 	usb_fill_bulk_urb(serial_priv->read_urb, serial->dev,
677 			  usb_rcvbulkpipe(serial->dev,
678 					  port0->bulk_in_endpointAddress),
679 			  serial_priv->read_buffer,
680 			  QT2_READ_BUFFER_SIZE,
681 			  qt2_read_bulk_callback, serial);
682 
683 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
684 	if (status != 0) {
685 		dev_err(&serial->dev->dev,
686 			"%s - submit read urb failed %i\n", __func__, status);
687 		usb_free_urb(serial_priv->read_urb);
688 		return status;
689 	}
690 
691 	return 0;
692 }
693 
694 static int qt2_attach(struct usb_serial *serial)
695 {
696 	struct qt2_serial_private *serial_priv;
697 	int status;
698 
699 	/* power on unit */
700 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
701 				 0xc2, 0x40, 0x8000, 0, NULL, 0,
702 				 QT2_USB_TIMEOUT);
703 	if (status < 0) {
704 		dev_err(&serial->dev->dev,
705 			"%s - failed to power on unit: %i\n", __func__, status);
706 		return status;
707 	}
708 
709 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
710 	if (!serial_priv)
711 		return -ENOMEM;
712 
713 	serial_priv->read_buffer = kmalloc(QT2_READ_BUFFER_SIZE, GFP_KERNEL);
714 	if (!serial_priv->read_buffer) {
715 		status = -ENOMEM;
716 		goto err_buf;
717 	}
718 
719 	usb_set_serial_data(serial, serial_priv);
720 
721 	status = qt2_setup_urbs(serial);
722 	if (status != 0)
723 		goto attach_failed;
724 
725 	return 0;
726 
727 attach_failed:
728 	kfree(serial_priv->read_buffer);
729 err_buf:
730 	kfree(serial_priv);
731 	return status;
732 }
733 
734 static int qt2_port_probe(struct usb_serial_port *port)
735 {
736 	struct usb_serial *serial = port->serial;
737 	struct qt2_port_private *port_priv;
738 	u8 bEndpointAddress;
739 
740 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
741 	if (!port_priv)
742 		return -ENOMEM;
743 
744 	spin_lock_init(&port_priv->lock);
745 	spin_lock_init(&port_priv->urb_lock);
746 	port_priv->port = port;
747 
748 	port_priv->write_buffer = kmalloc(QT2_WRITE_BUFFER_SIZE, GFP_KERNEL);
749 	if (!port_priv->write_buffer)
750 		goto err_buf;
751 
752 	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
753 	if (!port_priv->write_urb)
754 		goto err_urb;
755 
756 	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
757 	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
758 				usb_sndbulkpipe(serial->dev, bEndpointAddress),
759 				port_priv->write_buffer,
760 				QT2_WRITE_BUFFER_SIZE,
761 				qt2_write_bulk_callback, port);
762 
763 	usb_set_serial_port_data(port, port_priv);
764 
765 	return 0;
766 err_urb:
767 	kfree(port_priv->write_buffer);
768 err_buf:
769 	kfree(port_priv);
770 	return -ENOMEM;
771 }
772 
773 static int qt2_port_remove(struct usb_serial_port *port)
774 {
775 	struct qt2_port_private *port_priv;
776 
777 	port_priv = usb_get_serial_port_data(port);
778 	usb_free_urb(port_priv->write_urb);
779 	kfree(port_priv->write_buffer);
780 	kfree(port_priv);
781 
782 	return 0;
783 }
784 
785 static int qt2_tiocmget(struct tty_struct *tty)
786 {
787 	struct usb_serial_port *port = tty->driver_data;
788 	struct usb_device *dev = port->serial->dev;
789 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
790 	u8 *d;
791 	int r;
792 
793 	d = kzalloc(2, GFP_KERNEL);
794 	if (!d)
795 		return -ENOMEM;
796 
797 	r = qt2_getregister(dev, port_priv->device_port, UART_MCR, d);
798 	if (r < 0)
799 		goto mget_out;
800 
801 	r = qt2_getregister(dev, port_priv->device_port, UART_MSR, d + 1);
802 	if (r < 0)
803 		goto mget_out;
804 
805 	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
806 	    (d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
807 	    (d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
808 	    (d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
809 	    (d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
810 	    (d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
811 
812 mget_out:
813 	kfree(d);
814 	return r;
815 }
816 
817 static int qt2_tiocmset(struct tty_struct *tty,
818 			unsigned int set, unsigned int clear)
819 {
820 	struct qt2_port_private *port_priv;
821 
822 	port_priv = usb_get_serial_port_data(tty->driver_data);
823 	return update_mctrl(port_priv, set, clear);
824 }
825 
826 static void qt2_break_ctl(struct tty_struct *tty, int break_state)
827 {
828 	struct usb_serial_port *port = tty->driver_data;
829 	struct qt2_port_private *port_priv;
830 	int status;
831 	u16 val;
832 
833 	port_priv = usb_get_serial_port_data(port);
834 
835 	val = (break_state == -1) ? 1 : 0;
836 
837 	status = qt2_control_msg(port->serial->dev, QT2_BREAK_CONTROL,
838 				 val, port_priv->device_port);
839 	if (status < 0)
840 		dev_warn(&port->dev,
841 			 "%s - failed to send control message: %i\n", __func__,
842 			 status);
843 }
844 
845 
846 
847 static void qt2_dtr_rts(struct usb_serial_port *port, int on)
848 {
849 	struct usb_device *dev = port->serial->dev;
850 	struct qt2_port_private *port_priv = usb_get_serial_port_data(port);
851 
852 	/* Disable flow control */
853 	if (!on) {
854 		if (qt2_setregister(dev, port_priv->device_port,
855 					   UART_MCR, 0) < 0)
856 			dev_warn(&port->dev, "error from flowcontrol urb\n");
857 	}
858 	/* drop RTS and DTR */
859 	if (on)
860 		update_mctrl(port_priv, TIOCM_DTR | TIOCM_RTS, 0);
861 	else
862 		update_mctrl(port_priv, 0, TIOCM_DTR | TIOCM_RTS);
863 }
864 
865 static void qt2_update_msr(struct usb_serial_port *port, unsigned char *ch)
866 {
867 	struct qt2_port_private *port_priv;
868 	u8 newMSR = (u8) *ch;
869 	unsigned long flags;
870 
871 	port_priv = usb_get_serial_port_data(port);
872 
873 	spin_lock_irqsave(&port_priv->lock, flags);
874 	port_priv->shadowMSR = newMSR;
875 	spin_unlock_irqrestore(&port_priv->lock, flags);
876 
877 	if (newMSR & UART_MSR_ANY_DELTA) {
878 		/* update input line counters */
879 		if (newMSR & UART_MSR_DCTS)
880 			port->icount.cts++;
881 		if (newMSR & UART_MSR_DDSR)
882 			port->icount.dsr++;
883 		if (newMSR & UART_MSR_DDCD)
884 			port->icount.dcd++;
885 		if (newMSR & UART_MSR_TERI)
886 			port->icount.rng++;
887 
888 		wake_up_interruptible(&port->port.delta_msr_wait);
889 	}
890 }
891 
892 static void qt2_update_lsr(struct usb_serial_port *port, unsigned char *ch)
893 {
894 	struct qt2_port_private *port_priv;
895 	struct async_icount *icount;
896 	unsigned long flags;
897 	u8 newLSR = (u8) *ch;
898 
899 	port_priv = usb_get_serial_port_data(port);
900 
901 	if (newLSR & UART_LSR_BI)
902 		newLSR &= (u8) (UART_LSR_OE | UART_LSR_BI);
903 
904 	spin_lock_irqsave(&port_priv->lock, flags);
905 	port_priv->shadowLSR = newLSR;
906 	spin_unlock_irqrestore(&port_priv->lock, flags);
907 
908 	icount = &port->icount;
909 
910 	if (newLSR & UART_LSR_BRK_ERROR_BITS) {
911 
912 		if (newLSR & UART_LSR_BI)
913 			icount->brk++;
914 
915 		if (newLSR & UART_LSR_OE)
916 			icount->overrun++;
917 
918 		if (newLSR & UART_LSR_PE)
919 			icount->parity++;
920 
921 		if (newLSR & UART_LSR_FE)
922 			icount->frame++;
923 	}
924 
925 }
926 
927 static int qt2_write_room(struct tty_struct *tty)
928 {
929 	struct usb_serial_port *port = tty->driver_data;
930 	struct qt2_port_private *port_priv;
931 	unsigned long flags = 0;
932 	int r;
933 
934 	port_priv = usb_get_serial_port_data(port);
935 
936 	spin_lock_irqsave(&port_priv->urb_lock, flags);
937 
938 	if (port_priv->urb_in_use)
939 		r = 0;
940 	else
941 		r = QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE;
942 
943 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
944 
945 	return r;
946 }
947 
948 static int qt2_write(struct tty_struct *tty,
949 		     struct usb_serial_port *port,
950 		     const unsigned char *buf, int count)
951 {
952 	struct qt2_port_private *port_priv;
953 	struct urb *write_urb;
954 	unsigned char *data;
955 	unsigned long flags;
956 	int status;
957 	int bytes_out = 0;
958 
959 	port_priv = usb_get_serial_port_data(port);
960 
961 	if (port_priv->write_urb == NULL) {
962 		dev_err(&port->dev, "%s - no output urb\n", __func__);
963 		return 0;
964 	}
965 	write_urb = port_priv->write_urb;
966 
967 	count = min(count, QT2_WRITE_BUFFER_SIZE - QT2_WRITE_CONTROL_SIZE);
968 
969 	data = write_urb->transfer_buffer;
970 	spin_lock_irqsave(&port_priv->urb_lock, flags);
971 	if (port_priv->urb_in_use) {
972 		dev_err(&port->dev, "qt2_write - urb is in use\n");
973 		goto write_out;
974 	}
975 
976 	*data++ = QT2_CONTROL_BYTE;
977 	*data++ = QT2_CONTROL_BYTE;
978 	*data++ = port_priv->device_port;
979 	put_unaligned_le16(count, data);
980 	data += 2;
981 	memcpy(data, buf, count);
982 
983 	write_urb->transfer_buffer_length = count + QT2_WRITE_CONTROL_SIZE;
984 
985 	status = usb_submit_urb(write_urb, GFP_ATOMIC);
986 	if (status == 0) {
987 		port_priv->urb_in_use = true;
988 		bytes_out += count;
989 	}
990 
991 write_out:
992 	spin_unlock_irqrestore(&port_priv->urb_lock, flags);
993 	return bytes_out;
994 }
995 
996 
997 static struct usb_serial_driver qt2_device = {
998 	.driver = {
999 		.owner = THIS_MODULE,
1000 		.name = "quatech-serial",
1001 	},
1002 	.description	     = DRIVER_DESC,
1003 	.id_table	     = id_table,
1004 	.open		     = qt2_open,
1005 	.close		     = qt2_close,
1006 	.write               = qt2_write,
1007 	.write_room          = qt2_write_room,
1008 	.calc_num_ports      = qt2_calc_num_ports,
1009 	.attach              = qt2_attach,
1010 	.release             = qt2_release,
1011 	.disconnect          = qt2_disconnect,
1012 	.port_probe          = qt2_port_probe,
1013 	.port_remove         = qt2_port_remove,
1014 	.dtr_rts             = qt2_dtr_rts,
1015 	.break_ctl           = qt2_break_ctl,
1016 	.tiocmget            = qt2_tiocmget,
1017 	.tiocmset            = qt2_tiocmset,
1018 	.tiocmiwait          = usb_serial_generic_tiocmiwait,
1019 	.get_icount	     = usb_serial_generic_get_icount,
1020 	.ioctl               = qt2_ioctl,
1021 	.set_termios         = qt2_set_termios,
1022 };
1023 
1024 static struct usb_serial_driver *const serial_drivers[] = {
1025 	&qt2_device, NULL
1026 };
1027 
1028 module_usb_serial_driver(serial_drivers, id_table);
1029 
1030 MODULE_DESCRIPTION(DRIVER_DESC);
1031 MODULE_LICENSE("GPL");
1032