xref: /linux/drivers/usb/serial/oti6858.c (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
1 /*
2  * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
3  *
4  * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
5  * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
6  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
7  * Copyright (C) 2003 IBM Corp.
8  *
9  * Many thanks to the authors of pl2303 driver: all functions in this file
10  * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
11  *
12  * Warning! You use this driver on your own risk! The only official
13  * description of this device I have is datasheet from manufacturer,
14  * and it doesn't contain almost any information needed to write a driver.
15  * Almost all knowlegde used while writing this driver was gathered by:
16  *  - analyzing traffic between device and the M$ Windows 2000 driver,
17  *  - trying different bit combinations and checking pin states
18  *    with a voltmeter,
19  *  - receiving malformed frames and producing buffer overflows
20  *    to learn how errors are reported,
21  * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
22  * CONNECTED TO IT!
23  *
24  * This program is free software; you can redistribute it and/or modify
25  * it under the terms of the GNU General Public License as published by
26  * the Free Software Foundation; either version 2 of the License.
27  *
28  * See Documentation/usb/usb-serial.txt for more information on using this
29  * driver
30  *
31  * TODO:
32  *  - implement correct flushing for ioctls and oti6858_close()
33  *  - check how errors (rx overflow, parity error, framing error) are reported
34  *  - implement oti6858_break_ctl()
35  *  - implement more ioctls
36  *  - test/implement flow control
37  *  - allow setting custom baud rates
38  */
39 
40 #include <linux/kernel.h>
41 #include <linux/errno.h>
42 #include <linux/init.h>
43 #include <linux/slab.h>
44 #include <linux/tty.h>
45 #include <linux/tty_driver.h>
46 #include <linux/tty_flip.h>
47 #include <linux/serial.h>
48 #include <linux/module.h>
49 #include <linux/moduleparam.h>
50 #include <linux/spinlock.h>
51 #include <linux/usb.h>
52 #include <linux/usb/serial.h>
53 #include <linux/uaccess.h>
54 #include <linux/kfifo.h>
55 #include "oti6858.h"
56 
57 #define OTI6858_DESCRIPTION \
58 	"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
59 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
60 #define OTI6858_VERSION "0.2"
61 
62 static const struct usb_device_id id_table[] = {
63 	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
64 	{ }
65 };
66 
67 MODULE_DEVICE_TABLE(usb, id_table);
68 
69 /* requests */
70 #define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
71 #define	OTI6858_REQ_T_GET_STATUS	0x01
72 
73 #define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
74 #define	OTI6858_REQ_T_SET_LINE		0x00
75 
76 #define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
77 #define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
78 
79 /* format of the control packet */
80 struct oti6858_control_pkt {
81 	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
82 #define OTI6858_MAX_BAUD_RATE	3000000
83 	u8	frame_fmt;
84 #define FMT_STOP_BITS_MASK	0xc0
85 #define FMT_STOP_BITS_1		0x00
86 #define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
87 #define FMT_PARITY_MASK		0x38
88 #define FMT_PARITY_NONE		0x00
89 #define FMT_PARITY_ODD		0x08
90 #define FMT_PARITY_EVEN		0x18
91 #define FMT_PARITY_MARK		0x28
92 #define FMT_PARITY_SPACE	0x38
93 #define FMT_DATA_BITS_MASK	0x03
94 #define FMT_DATA_BITS_5		0x00
95 #define FMT_DATA_BITS_6		0x01
96 #define FMT_DATA_BITS_7		0x02
97 #define FMT_DATA_BITS_8		0x03
98 	u8	something;	/* always equals 0x43 */
99 	u8	control;	/* settings of flow control lines */
100 #define CONTROL_MASK		0x0c
101 #define CONTROL_DTR_HIGH	0x08
102 #define CONTROL_RTS_HIGH	0x04
103 	u8	tx_status;
104 #define	TX_BUFFER_EMPTIED	0x09
105 	u8	pin_state;
106 #define PIN_MASK		0x3f
107 #define PIN_RTS			0x20	/* output pin */
108 #define PIN_CTS			0x10	/* input pin, active low */
109 #define PIN_DSR			0x08	/* input pin, active low */
110 #define PIN_DTR			0x04	/* output pin */
111 #define PIN_RI			0x02	/* input pin, active low */
112 #define PIN_DCD			0x01	/* input pin, active low */
113 	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
114 };
115 
116 #define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
117 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
118 	(((a)->divisor == (priv)->pending_setup.divisor) \
119 	  && ((a)->control == (priv)->pending_setup.control) \
120 	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
121 
122 /* function prototypes */
123 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
124 static void oti6858_close(struct usb_serial_port *port);
125 static void oti6858_set_termios(struct tty_struct *tty,
126 			struct usb_serial_port *port, struct ktermios *old);
127 static void oti6858_init_termios(struct tty_struct *tty);
128 static int oti6858_ioctl(struct tty_struct *tty,
129 			unsigned int cmd, unsigned long arg);
130 static void oti6858_read_int_callback(struct urb *urb);
131 static void oti6858_read_bulk_callback(struct urb *urb);
132 static void oti6858_write_bulk_callback(struct urb *urb);
133 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
134 			const unsigned char *buf, int count);
135 static int oti6858_write_room(struct tty_struct *tty);
136 static int oti6858_chars_in_buffer(struct tty_struct *tty);
137 static int oti6858_tiocmget(struct tty_struct *tty);
138 static int oti6858_tiocmset(struct tty_struct *tty,
139 				unsigned int set, unsigned int clear);
140 static int oti6858_startup(struct usb_serial *serial);
141 static void oti6858_release(struct usb_serial *serial);
142 
143 /* device info */
144 static struct usb_serial_driver oti6858_device = {
145 	.driver = {
146 		.owner =	THIS_MODULE,
147 		.name =		"oti6858",
148 	},
149 	.id_table =		id_table,
150 	.num_ports =		1,
151 	.open =			oti6858_open,
152 	.close =		oti6858_close,
153 	.write =		oti6858_write,
154 	.ioctl =		oti6858_ioctl,
155 	.set_termios =		oti6858_set_termios,
156 	.init_termios = 	oti6858_init_termios,
157 	.tiocmget =		oti6858_tiocmget,
158 	.tiocmset =		oti6858_tiocmset,
159 	.read_bulk_callback =	oti6858_read_bulk_callback,
160 	.read_int_callback =	oti6858_read_int_callback,
161 	.write_bulk_callback =	oti6858_write_bulk_callback,
162 	.write_room =		oti6858_write_room,
163 	.chars_in_buffer =	oti6858_chars_in_buffer,
164 	.attach =		oti6858_startup,
165 	.release =		oti6858_release,
166 };
167 
168 static struct usb_serial_driver * const serial_drivers[] = {
169 	&oti6858_device, NULL
170 };
171 
172 struct oti6858_private {
173 	spinlock_t lock;
174 
175 	struct oti6858_control_pkt status;
176 
177 	struct {
178 		u8 read_urb_in_use;
179 		u8 write_urb_in_use;
180 	} flags;
181 	struct delayed_work delayed_write_work;
182 
183 	struct {
184 		__le16 divisor;
185 		u8 frame_fmt;
186 		u8 control;
187 	} pending_setup;
188 	u8 transient;
189 	u8 setup_done;
190 	struct delayed_work delayed_setup_work;
191 
192 	wait_queue_head_t intr_wait;
193 	struct usb_serial_port *port;   /* USB port with which associated */
194 };
195 
196 static void setup_line(struct work_struct *work)
197 {
198 	struct oti6858_private *priv = container_of(work,
199 			struct oti6858_private, delayed_setup_work.work);
200 	struct usb_serial_port *port = priv->port;
201 	struct oti6858_control_pkt *new_setup;
202 	unsigned long flags;
203 	int result;
204 
205 	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
206 	if (new_setup == NULL) {
207 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
208 		/* we will try again */
209 		schedule_delayed_work(&priv->delayed_setup_work,
210 						msecs_to_jiffies(2));
211 		return;
212 	}
213 
214 	result = usb_control_msg(port->serial->dev,
215 				usb_rcvctrlpipe(port->serial->dev, 0),
216 				OTI6858_REQ_T_GET_STATUS,
217 				OTI6858_REQ_GET_STATUS,
218 				0, 0,
219 				new_setup, OTI6858_CTRL_PKT_SIZE,
220 				100);
221 
222 	if (result != OTI6858_CTRL_PKT_SIZE) {
223 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
224 		kfree(new_setup);
225 		/* we will try again */
226 		schedule_delayed_work(&priv->delayed_setup_work,
227 							msecs_to_jiffies(2));
228 		return;
229 	}
230 
231 	spin_lock_irqsave(&priv->lock, flags);
232 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
233 		new_setup->divisor = priv->pending_setup.divisor;
234 		new_setup->control = priv->pending_setup.control;
235 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
236 
237 		spin_unlock_irqrestore(&priv->lock, flags);
238 		result = usb_control_msg(port->serial->dev,
239 					usb_sndctrlpipe(port->serial->dev, 0),
240 					OTI6858_REQ_T_SET_LINE,
241 					OTI6858_REQ_SET_LINE,
242 					0, 0,
243 					new_setup, OTI6858_CTRL_PKT_SIZE,
244 					100);
245 	} else {
246 		spin_unlock_irqrestore(&priv->lock, flags);
247 		result = 0;
248 	}
249 	kfree(new_setup);
250 
251 	spin_lock_irqsave(&priv->lock, flags);
252 	if (result != OTI6858_CTRL_PKT_SIZE)
253 		priv->transient = 0;
254 	priv->setup_done = 1;
255 	spin_unlock_irqrestore(&priv->lock, flags);
256 
257 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
258 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
259 	if (result != 0) {
260 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
261 			__func__, result);
262 	}
263 }
264 
265 static void send_data(struct work_struct *work)
266 {
267 	struct oti6858_private *priv = container_of(work,
268 			struct oti6858_private, delayed_write_work.work);
269 	struct usb_serial_port *port = priv->port;
270 	int count = 0, result;
271 	unsigned long flags;
272 	u8 *allow;
273 
274 	spin_lock_irqsave(&priv->lock, flags);
275 	if (priv->flags.write_urb_in_use) {
276 		spin_unlock_irqrestore(&priv->lock, flags);
277 		schedule_delayed_work(&priv->delayed_write_work,
278 						msecs_to_jiffies(2));
279 		return;
280 	}
281 	priv->flags.write_urb_in_use = 1;
282 	spin_unlock_irqrestore(&priv->lock, flags);
283 
284 	spin_lock_irqsave(&port->lock, flags);
285 	count = kfifo_len(&port->write_fifo);
286 	spin_unlock_irqrestore(&port->lock, flags);
287 
288 	if (count > port->bulk_out_size)
289 		count = port->bulk_out_size;
290 
291 	if (count != 0) {
292 		allow = kmalloc(1, GFP_KERNEL);
293 		if (!allow) {
294 			dev_err_console(port, "%s(): kmalloc failed\n",
295 					__func__);
296 			return;
297 		}
298 		result = usb_control_msg(port->serial->dev,
299 				usb_rcvctrlpipe(port->serial->dev, 0),
300 				OTI6858_REQ_T_CHECK_TXBUFF,
301 				OTI6858_REQ_CHECK_TXBUFF,
302 				count, 0, allow, 1, 100);
303 		if (result != 1 || *allow != 0)
304 			count = 0;
305 		kfree(allow);
306 	}
307 
308 	if (count == 0) {
309 		priv->flags.write_urb_in_use = 0;
310 
311 		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
312 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
313 		if (result != 0) {
314 			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
315 				__func__, result);
316 		}
317 		return;
318 	}
319 
320 	count = kfifo_out_locked(&port->write_fifo,
321 					port->write_urb->transfer_buffer,
322 					count, &port->lock);
323 	port->write_urb->transfer_buffer_length = count;
324 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
325 	if (result != 0) {
326 		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
327 				__func__, result);
328 		priv->flags.write_urb_in_use = 0;
329 	}
330 
331 	usb_serial_port_softint(port);
332 }
333 
334 static int oti6858_startup(struct usb_serial *serial)
335 {
336 	struct usb_serial_port *port = serial->port[0];
337 	struct oti6858_private *priv;
338 	int i;
339 
340 	for (i = 0; i < serial->num_ports; ++i) {
341 		priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
342 		if (!priv)
343 			break;
344 
345 		spin_lock_init(&priv->lock);
346 		init_waitqueue_head(&priv->intr_wait);
347 /*		INIT_WORK(&priv->setup_work, setup_line, serial->port[i]); */
348 /*		INIT_WORK(&priv->write_work, send_data, serial->port[i]); */
349 		priv->port = port;
350 		INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
351 		INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
352 
353 		usb_set_serial_port_data(serial->port[i], priv);
354 	}
355 	if (i == serial->num_ports)
356 		return 0;
357 
358 	for (--i; i >= 0; --i) {
359 		priv = usb_get_serial_port_data(serial->port[i]);
360 		kfree(priv);
361 		usb_set_serial_port_data(serial->port[i], NULL);
362 	}
363 	return -ENOMEM;
364 }
365 
366 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
367 			const unsigned char *buf, int count)
368 {
369 	if (!count)
370 		return count;
371 
372 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
373 
374 	return count;
375 }
376 
377 static int oti6858_write_room(struct tty_struct *tty)
378 {
379 	struct usb_serial_port *port = tty->driver_data;
380 	int room = 0;
381 	unsigned long flags;
382 
383 	spin_lock_irqsave(&port->lock, flags);
384 	room = kfifo_avail(&port->write_fifo);
385 	spin_unlock_irqrestore(&port->lock, flags);
386 
387 	return room;
388 }
389 
390 static int oti6858_chars_in_buffer(struct tty_struct *tty)
391 {
392 	struct usb_serial_port *port = tty->driver_data;
393 	int chars = 0;
394 	unsigned long flags;
395 
396 	spin_lock_irqsave(&port->lock, flags);
397 	chars = kfifo_len(&port->write_fifo);
398 	spin_unlock_irqrestore(&port->lock, flags);
399 
400 	return chars;
401 }
402 
403 static void oti6858_init_termios(struct tty_struct *tty)
404 {
405 	tty->termios = tty_std_termios;
406 	tty->termios.c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
407 	tty->termios.c_ispeed = 38400;
408 	tty->termios.c_ospeed = 38400;
409 }
410 
411 static void oti6858_set_termios(struct tty_struct *tty,
412 		struct usb_serial_port *port, struct ktermios *old_termios)
413 {
414 	struct oti6858_private *priv = usb_get_serial_port_data(port);
415 	unsigned long flags;
416 	unsigned int cflag;
417 	u8 frame_fmt, control;
418 	__le16 divisor;
419 	int br;
420 
421 	if (!tty)
422 		return;
423 
424 	cflag = tty->termios.c_cflag;
425 
426 	spin_lock_irqsave(&priv->lock, flags);
427 	divisor = priv->pending_setup.divisor;
428 	frame_fmt = priv->pending_setup.frame_fmt;
429 	control = priv->pending_setup.control;
430 	spin_unlock_irqrestore(&priv->lock, flags);
431 
432 	frame_fmt &= ~FMT_DATA_BITS_MASK;
433 	switch (cflag & CSIZE) {
434 	case CS5:
435 		frame_fmt |= FMT_DATA_BITS_5;
436 		break;
437 	case CS6:
438 		frame_fmt |= FMT_DATA_BITS_6;
439 		break;
440 	case CS7:
441 		frame_fmt |= FMT_DATA_BITS_7;
442 		break;
443 	default:
444 	case CS8:
445 		frame_fmt |= FMT_DATA_BITS_8;
446 		break;
447 	}
448 
449 	/* manufacturer claims that this device can work with baud rates
450 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
451 	 * guarantee that any other baud rate will work (especially
452 	 * the higher ones)
453 	 */
454 	br = tty_get_baud_rate(tty);
455 	if (br == 0) {
456 		divisor = 0;
457 	} else {
458 		int real_br;
459 		int new_divisor;
460 		br = min(br, OTI6858_MAX_BAUD_RATE);
461 
462 		new_divisor = (96000000 + 8 * br) / (16 * br);
463 		real_br = 96000000 / (16 * new_divisor);
464 		divisor = cpu_to_le16(new_divisor);
465 		tty_encode_baud_rate(tty, real_br, real_br);
466 	}
467 
468 	frame_fmt &= ~FMT_STOP_BITS_MASK;
469 	if ((cflag & CSTOPB) != 0)
470 		frame_fmt |= FMT_STOP_BITS_2;
471 	else
472 		frame_fmt |= FMT_STOP_BITS_1;
473 
474 	frame_fmt &= ~FMT_PARITY_MASK;
475 	if ((cflag & PARENB) != 0) {
476 		if ((cflag & PARODD) != 0)
477 			frame_fmt |= FMT_PARITY_ODD;
478 		else
479 			frame_fmt |= FMT_PARITY_EVEN;
480 	} else {
481 		frame_fmt |= FMT_PARITY_NONE;
482 	}
483 
484 	control &= ~CONTROL_MASK;
485 	if ((cflag & CRTSCTS) != 0)
486 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
487 
488 	/* change control lines if we are switching to or from B0 */
489 	/* FIXME:
490 	spin_lock_irqsave(&priv->lock, flags);
491 	control = priv->line_control;
492 	if ((cflag & CBAUD) == B0)
493 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
494 	else
495 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
496 	if (control != priv->line_control) {
497 		control = priv->line_control;
498 		spin_unlock_irqrestore(&priv->lock, flags);
499 		set_control_lines(serial->dev, control);
500 	} else {
501 		spin_unlock_irqrestore(&priv->lock, flags);
502 	}
503 	*/
504 
505 	spin_lock_irqsave(&priv->lock, flags);
506 	if (divisor != priv->pending_setup.divisor
507 			|| control != priv->pending_setup.control
508 			|| frame_fmt != priv->pending_setup.frame_fmt) {
509 		priv->pending_setup.divisor = divisor;
510 		priv->pending_setup.control = control;
511 		priv->pending_setup.frame_fmt = frame_fmt;
512 	}
513 	spin_unlock_irqrestore(&priv->lock, flags);
514 }
515 
516 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
517 {
518 	struct oti6858_private *priv = usb_get_serial_port_data(port);
519 	struct ktermios tmp_termios;
520 	struct usb_serial *serial = port->serial;
521 	struct oti6858_control_pkt *buf;
522 	unsigned long flags;
523 	int result;
524 
525 	usb_clear_halt(serial->dev, port->write_urb->pipe);
526 	usb_clear_halt(serial->dev, port->read_urb->pipe);
527 
528 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
529 	if (buf == NULL) {
530 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
531 		return -ENOMEM;
532 	}
533 
534 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
535 				OTI6858_REQ_T_GET_STATUS,
536 				OTI6858_REQ_GET_STATUS,
537 				0, 0,
538 				buf, OTI6858_CTRL_PKT_SIZE,
539 				100);
540 	if (result != OTI6858_CTRL_PKT_SIZE) {
541 		/* assume default (after power-on reset) values */
542 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
543 		buf->frame_fmt = 0x03;	/* 8N1 */
544 		buf->something = 0x43;
545 		buf->control = 0x4c;	/* DTR, RTS */
546 		buf->tx_status = 0x00;
547 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
548 		buf->rx_bytes_avail = 0x00;
549 	}
550 
551 	spin_lock_irqsave(&priv->lock, flags);
552 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
553 	priv->pending_setup.divisor = buf->divisor;
554 	priv->pending_setup.frame_fmt = buf->frame_fmt;
555 	priv->pending_setup.control = buf->control;
556 	spin_unlock_irqrestore(&priv->lock, flags);
557 	kfree(buf);
558 
559 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
560 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
561 	if (result != 0) {
562 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
563 			__func__, result);
564 		oti6858_close(port);
565 		return result;
566 	}
567 
568 	/* setup termios */
569 	if (tty)
570 		oti6858_set_termios(tty, port, &tmp_termios);
571 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
572 	return 0;
573 }
574 
575 static void oti6858_close(struct usb_serial_port *port)
576 {
577 	struct oti6858_private *priv = usb_get_serial_port_data(port);
578 	unsigned long flags;
579 
580 	spin_lock_irqsave(&port->lock, flags);
581 	/* clear out any remaining data in the buffer */
582 	kfifo_reset_out(&port->write_fifo);
583 	spin_unlock_irqrestore(&port->lock, flags);
584 
585 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
586 
587 	/* cancel scheduled setup */
588 	cancel_delayed_work_sync(&priv->delayed_setup_work);
589 	cancel_delayed_work_sync(&priv->delayed_write_work);
590 
591 	/* shutdown our urbs */
592 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
593 	usb_kill_urb(port->write_urb);
594 	usb_kill_urb(port->read_urb);
595 	usb_kill_urb(port->interrupt_in_urb);
596 }
597 
598 static int oti6858_tiocmset(struct tty_struct *tty,
599 				unsigned int set, unsigned int clear)
600 {
601 	struct usb_serial_port *port = tty->driver_data;
602 	struct oti6858_private *priv = usb_get_serial_port_data(port);
603 	unsigned long flags;
604 	u8 control;
605 
606 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
607 		__func__, set, clear);
608 
609 	/* FIXME: check if this is correct (active high/low) */
610 	spin_lock_irqsave(&priv->lock, flags);
611 	control = priv->pending_setup.control;
612 	if ((set & TIOCM_RTS) != 0)
613 		control |= CONTROL_RTS_HIGH;
614 	if ((set & TIOCM_DTR) != 0)
615 		control |= CONTROL_DTR_HIGH;
616 	if ((clear & TIOCM_RTS) != 0)
617 		control &= ~CONTROL_RTS_HIGH;
618 	if ((clear & TIOCM_DTR) != 0)
619 		control &= ~CONTROL_DTR_HIGH;
620 
621 	if (control != priv->pending_setup.control)
622 		priv->pending_setup.control = control;
623 
624 	spin_unlock_irqrestore(&priv->lock, flags);
625 	return 0;
626 }
627 
628 static int oti6858_tiocmget(struct tty_struct *tty)
629 {
630 	struct usb_serial_port *port = tty->driver_data;
631 	struct oti6858_private *priv = usb_get_serial_port_data(port);
632 	unsigned long flags;
633 	unsigned pin_state;
634 	unsigned result = 0;
635 
636 	spin_lock_irqsave(&priv->lock, flags);
637 	pin_state = priv->status.pin_state & PIN_MASK;
638 	spin_unlock_irqrestore(&priv->lock, flags);
639 
640 	/* FIXME: check if this is correct (active high/low) */
641 	if ((pin_state & PIN_RTS) != 0)
642 		result |= TIOCM_RTS;
643 	if ((pin_state & PIN_CTS) != 0)
644 		result |= TIOCM_CTS;
645 	if ((pin_state & PIN_DSR) != 0)
646 		result |= TIOCM_DSR;
647 	if ((pin_state & PIN_DTR) != 0)
648 		result |= TIOCM_DTR;
649 	if ((pin_state & PIN_RI) != 0)
650 		result |= TIOCM_RI;
651 	if ((pin_state & PIN_DCD) != 0)
652 		result |= TIOCM_CD;
653 
654 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
655 
656 	return result;
657 }
658 
659 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
660 {
661 	struct oti6858_private *priv = usb_get_serial_port_data(port);
662 	unsigned long flags;
663 	unsigned int prev, status;
664 	unsigned int changed;
665 
666 	spin_lock_irqsave(&priv->lock, flags);
667 	prev = priv->status.pin_state;
668 	spin_unlock_irqrestore(&priv->lock, flags);
669 
670 	while (1) {
671 		wait_event_interruptible(priv->intr_wait,
672 					priv->status.pin_state != prev);
673 		if (signal_pending(current))
674 			return -ERESTARTSYS;
675 
676 		spin_lock_irqsave(&priv->lock, flags);
677 		status = priv->status.pin_state & PIN_MASK;
678 		spin_unlock_irqrestore(&priv->lock, flags);
679 
680 		changed = prev ^ status;
681 		/* FIXME: check if this is correct (active high/low) */
682 		if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
683 		    ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
684 		    ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
685 		    ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
686 			return 0;
687 		prev = status;
688 	}
689 
690 	/* NOTREACHED */
691 	return 0;
692 }
693 
694 static int oti6858_ioctl(struct tty_struct *tty,
695 			unsigned int cmd, unsigned long arg)
696 {
697 	struct usb_serial_port *port = tty->driver_data;
698 
699 	dev_dbg(&port->dev, "%s(cmd = 0x%04x, arg = 0x%08lx)\n", __func__, cmd, arg);
700 
701 	switch (cmd) {
702 	case TIOCMIWAIT:
703 		dev_dbg(&port->dev, "%s(): TIOCMIWAIT\n", __func__);
704 		return wait_modem_info(port, arg);
705 	default:
706 		dev_dbg(&port->dev, "%s(): 0x%04x not supported\n", __func__, cmd);
707 		break;
708 	}
709 	return -ENOIOCTLCMD;
710 }
711 
712 
713 static void oti6858_release(struct usb_serial *serial)
714 {
715 	int i;
716 
717 	for (i = 0; i < serial->num_ports; ++i)
718 		kfree(usb_get_serial_port_data(serial->port[i]));
719 }
720 
721 static void oti6858_read_int_callback(struct urb *urb)
722 {
723 	struct usb_serial_port *port =  urb->context;
724 	struct oti6858_private *priv = usb_get_serial_port_data(port);
725 	int transient = 0, can_recv = 0, resubmit = 1;
726 	int status = urb->status;
727 
728 	switch (status) {
729 	case 0:
730 		/* success */
731 		break;
732 	case -ECONNRESET:
733 	case -ENOENT:
734 	case -ESHUTDOWN:
735 		/* this urb is terminated, clean up */
736 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
737 			__func__, status);
738 		return;
739 	default:
740 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
741 			__func__, status);
742 		break;
743 	}
744 
745 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
746 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
747 		unsigned long flags;
748 
749 		spin_lock_irqsave(&priv->lock, flags);
750 
751 		if (!priv->transient) {
752 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
753 				if (xs->rx_bytes_avail == 0) {
754 					priv->transient = 4;
755 					priv->setup_done = 0;
756 					resubmit = 0;
757 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
758 					schedule_delayed_work(&priv->delayed_setup_work, 0);
759 				}
760 			}
761 		} else {
762 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
763 				priv->transient = 0;
764 			} else if (!priv->setup_done) {
765 				resubmit = 0;
766 			} else if (--priv->transient == 0) {
767 				if (xs->rx_bytes_avail == 0) {
768 					priv->transient = 4;
769 					priv->setup_done = 0;
770 					resubmit = 0;
771 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
772 					schedule_delayed_work(&priv->delayed_setup_work, 0);
773 				}
774 			}
775 		}
776 
777 		if (!priv->transient) {
778 			if (xs->pin_state != priv->status.pin_state)
779 				wake_up_interruptible(&priv->intr_wait);
780 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
781 		}
782 
783 		if (!priv->transient && xs->rx_bytes_avail != 0) {
784 			can_recv = xs->rx_bytes_avail;
785 			priv->flags.read_urb_in_use = 1;
786 		}
787 
788 		transient = priv->transient;
789 		spin_unlock_irqrestore(&priv->lock, flags);
790 	}
791 
792 	if (can_recv) {
793 		int result;
794 
795 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
796 		if (result != 0) {
797 			priv->flags.read_urb_in_use = 0;
798 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
799 					" error %d\n", __func__, result);
800 		} else {
801 			resubmit = 0;
802 		}
803 	} else if (!transient) {
804 		unsigned long flags;
805 		int count;
806 
807 		spin_lock_irqsave(&port->lock, flags);
808 		count = kfifo_len(&port->write_fifo);
809 		spin_unlock_irqrestore(&port->lock, flags);
810 
811 		spin_lock_irqsave(&priv->lock, flags);
812 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
813 			schedule_delayed_work(&priv->delayed_write_work, 0);
814 			resubmit = 0;
815 		}
816 		spin_unlock_irqrestore(&priv->lock, flags);
817 	}
818 
819 	if (resubmit) {
820 		int result;
821 
822 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
823 		result = usb_submit_urb(urb, GFP_ATOMIC);
824 		if (result != 0) {
825 			dev_err(&urb->dev->dev,
826 					"%s(): usb_submit_urb() failed with"
827 					" error %d\n", __func__, result);
828 		}
829 	}
830 }
831 
832 static void oti6858_read_bulk_callback(struct urb *urb)
833 {
834 	struct usb_serial_port *port =  urb->context;
835 	struct oti6858_private *priv = usb_get_serial_port_data(port);
836 	struct tty_struct *tty;
837 	unsigned char *data = urb->transfer_buffer;
838 	unsigned long flags;
839 	int status = urb->status;
840 	int result;
841 
842 	spin_lock_irqsave(&priv->lock, flags);
843 	priv->flags.read_urb_in_use = 0;
844 	spin_unlock_irqrestore(&priv->lock, flags);
845 
846 	if (status != 0) {
847 		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
848 		return;
849 	}
850 
851 	tty = tty_port_tty_get(&port->port);
852 	if (tty != NULL && urb->actual_length > 0) {
853 		tty_insert_flip_string(tty, data, urb->actual_length);
854 		tty_flip_buffer_push(tty);
855 	}
856 	tty_kref_put(tty);
857 
858 	/* schedule the interrupt urb */
859 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
860 	if (result != 0 && result != -EPERM) {
861 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
862 				" error %d\n", __func__, result);
863 	}
864 }
865 
866 static void oti6858_write_bulk_callback(struct urb *urb)
867 {
868 	struct usb_serial_port *port =  urb->context;
869 	struct oti6858_private *priv = usb_get_serial_port_data(port);
870 	int status = urb->status;
871 	int result;
872 
873 	switch (status) {
874 	case 0:
875 		/* success */
876 		break;
877 	case -ECONNRESET:
878 	case -ENOENT:
879 	case -ESHUTDOWN:
880 		/* this urb is terminated, clean up */
881 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
882 		priv->flags.write_urb_in_use = 0;
883 		return;
884 	default:
885 		/* error in the urb, so we have to resubmit it */
886 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
887 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
888 
889 		port->write_urb->transfer_buffer_length = 1;
890 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
891 		if (result) {
892 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
893 					" error %d\n", __func__, result);
894 		} else {
895 			return;
896 		}
897 	}
898 
899 	priv->flags.write_urb_in_use = 0;
900 
901 	/* schedule the interrupt urb if we are still open */
902 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
903 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
904 	if (result != 0) {
905 		dev_err(&port->dev, "%s(): failed submitting int urb,"
906 					" error %d\n", __func__, result);
907 	}
908 }
909 
910 module_usb_serial_driver(serial_drivers, id_table);
911 
912 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
913 MODULE_AUTHOR(OTI6858_AUTHOR);
914 MODULE_VERSION(OTI6858_VERSION);
915 MODULE_LICENSE("GPL");
916