xref: /openbmc/linux/drivers/usb/serial/oti6858.c (revision 05bcf503)
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_port_probe(struct usb_serial_port *port);
141 static int oti6858_port_remove(struct usb_serial_port *port);
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 	.port_probe =		oti6858_port_probe,
165 	.port_remove =		oti6858_port_remove,
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_port_probe(struct usb_serial_port *port)
335 {
336 	struct oti6858_private *priv;
337 
338 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
339 	if (!priv)
340 		return -ENOMEM;
341 
342 	spin_lock_init(&priv->lock);
343 	init_waitqueue_head(&priv->intr_wait);
344 	priv->port = port;
345 	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
346 	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
347 
348 	usb_set_serial_port_data(port, priv);
349 
350 	return 0;
351 }
352 
353 static int oti6858_port_remove(struct usb_serial_port *port)
354 {
355 	struct oti6858_private *priv;
356 
357 	priv = usb_get_serial_port_data(port);
358 	kfree(priv);
359 
360 	return 0;
361 }
362 
363 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
364 			const unsigned char *buf, int count)
365 {
366 	if (!count)
367 		return count;
368 
369 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
370 
371 	return count;
372 }
373 
374 static int oti6858_write_room(struct tty_struct *tty)
375 {
376 	struct usb_serial_port *port = tty->driver_data;
377 	int room = 0;
378 	unsigned long flags;
379 
380 	spin_lock_irqsave(&port->lock, flags);
381 	room = kfifo_avail(&port->write_fifo);
382 	spin_unlock_irqrestore(&port->lock, flags);
383 
384 	return room;
385 }
386 
387 static int oti6858_chars_in_buffer(struct tty_struct *tty)
388 {
389 	struct usb_serial_port *port = tty->driver_data;
390 	int chars = 0;
391 	unsigned long flags;
392 
393 	spin_lock_irqsave(&port->lock, flags);
394 	chars = kfifo_len(&port->write_fifo);
395 	spin_unlock_irqrestore(&port->lock, flags);
396 
397 	return chars;
398 }
399 
400 static void oti6858_init_termios(struct tty_struct *tty)
401 {
402 	tty->termios = tty_std_termios;
403 	tty->termios.c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
404 	tty->termios.c_ispeed = 38400;
405 	tty->termios.c_ospeed = 38400;
406 }
407 
408 static void oti6858_set_termios(struct tty_struct *tty,
409 		struct usb_serial_port *port, struct ktermios *old_termios)
410 {
411 	struct oti6858_private *priv = usb_get_serial_port_data(port);
412 	unsigned long flags;
413 	unsigned int cflag;
414 	u8 frame_fmt, control;
415 	__le16 divisor;
416 	int br;
417 
418 	if (!tty)
419 		return;
420 
421 	cflag = tty->termios.c_cflag;
422 
423 	spin_lock_irqsave(&priv->lock, flags);
424 	divisor = priv->pending_setup.divisor;
425 	frame_fmt = priv->pending_setup.frame_fmt;
426 	control = priv->pending_setup.control;
427 	spin_unlock_irqrestore(&priv->lock, flags);
428 
429 	frame_fmt &= ~FMT_DATA_BITS_MASK;
430 	switch (cflag & CSIZE) {
431 	case CS5:
432 		frame_fmt |= FMT_DATA_BITS_5;
433 		break;
434 	case CS6:
435 		frame_fmt |= FMT_DATA_BITS_6;
436 		break;
437 	case CS7:
438 		frame_fmt |= FMT_DATA_BITS_7;
439 		break;
440 	default:
441 	case CS8:
442 		frame_fmt |= FMT_DATA_BITS_8;
443 		break;
444 	}
445 
446 	/* manufacturer claims that this device can work with baud rates
447 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
448 	 * guarantee that any other baud rate will work (especially
449 	 * the higher ones)
450 	 */
451 	br = tty_get_baud_rate(tty);
452 	if (br == 0) {
453 		divisor = 0;
454 	} else {
455 		int real_br;
456 		int new_divisor;
457 		br = min(br, OTI6858_MAX_BAUD_RATE);
458 
459 		new_divisor = (96000000 + 8 * br) / (16 * br);
460 		real_br = 96000000 / (16 * new_divisor);
461 		divisor = cpu_to_le16(new_divisor);
462 		tty_encode_baud_rate(tty, real_br, real_br);
463 	}
464 
465 	frame_fmt &= ~FMT_STOP_BITS_MASK;
466 	if ((cflag & CSTOPB) != 0)
467 		frame_fmt |= FMT_STOP_BITS_2;
468 	else
469 		frame_fmt |= FMT_STOP_BITS_1;
470 
471 	frame_fmt &= ~FMT_PARITY_MASK;
472 	if ((cflag & PARENB) != 0) {
473 		if ((cflag & PARODD) != 0)
474 			frame_fmt |= FMT_PARITY_ODD;
475 		else
476 			frame_fmt |= FMT_PARITY_EVEN;
477 	} else {
478 		frame_fmt |= FMT_PARITY_NONE;
479 	}
480 
481 	control &= ~CONTROL_MASK;
482 	if ((cflag & CRTSCTS) != 0)
483 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
484 
485 	/* change control lines if we are switching to or from B0 */
486 	/* FIXME:
487 	spin_lock_irqsave(&priv->lock, flags);
488 	control = priv->line_control;
489 	if ((cflag & CBAUD) == B0)
490 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
491 	else
492 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
493 	if (control != priv->line_control) {
494 		control = priv->line_control;
495 		spin_unlock_irqrestore(&priv->lock, flags);
496 		set_control_lines(serial->dev, control);
497 	} else {
498 		spin_unlock_irqrestore(&priv->lock, flags);
499 	}
500 	*/
501 
502 	spin_lock_irqsave(&priv->lock, flags);
503 	if (divisor != priv->pending_setup.divisor
504 			|| control != priv->pending_setup.control
505 			|| frame_fmt != priv->pending_setup.frame_fmt) {
506 		priv->pending_setup.divisor = divisor;
507 		priv->pending_setup.control = control;
508 		priv->pending_setup.frame_fmt = frame_fmt;
509 	}
510 	spin_unlock_irqrestore(&priv->lock, flags);
511 }
512 
513 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
514 {
515 	struct oti6858_private *priv = usb_get_serial_port_data(port);
516 	struct ktermios tmp_termios;
517 	struct usb_serial *serial = port->serial;
518 	struct oti6858_control_pkt *buf;
519 	unsigned long flags;
520 	int result;
521 
522 	usb_clear_halt(serial->dev, port->write_urb->pipe);
523 	usb_clear_halt(serial->dev, port->read_urb->pipe);
524 
525 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
526 	if (buf == NULL) {
527 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
528 		return -ENOMEM;
529 	}
530 
531 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
532 				OTI6858_REQ_T_GET_STATUS,
533 				OTI6858_REQ_GET_STATUS,
534 				0, 0,
535 				buf, OTI6858_CTRL_PKT_SIZE,
536 				100);
537 	if (result != OTI6858_CTRL_PKT_SIZE) {
538 		/* assume default (after power-on reset) values */
539 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
540 		buf->frame_fmt = 0x03;	/* 8N1 */
541 		buf->something = 0x43;
542 		buf->control = 0x4c;	/* DTR, RTS */
543 		buf->tx_status = 0x00;
544 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
545 		buf->rx_bytes_avail = 0x00;
546 	}
547 
548 	spin_lock_irqsave(&priv->lock, flags);
549 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
550 	priv->pending_setup.divisor = buf->divisor;
551 	priv->pending_setup.frame_fmt = buf->frame_fmt;
552 	priv->pending_setup.control = buf->control;
553 	spin_unlock_irqrestore(&priv->lock, flags);
554 	kfree(buf);
555 
556 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
557 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
558 	if (result != 0) {
559 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
560 			__func__, result);
561 		oti6858_close(port);
562 		return result;
563 	}
564 
565 	/* setup termios */
566 	if (tty)
567 		oti6858_set_termios(tty, port, &tmp_termios);
568 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
569 	return 0;
570 }
571 
572 static void oti6858_close(struct usb_serial_port *port)
573 {
574 	struct oti6858_private *priv = usb_get_serial_port_data(port);
575 	unsigned long flags;
576 
577 	spin_lock_irqsave(&port->lock, flags);
578 	/* clear out any remaining data in the buffer */
579 	kfifo_reset_out(&port->write_fifo);
580 	spin_unlock_irqrestore(&port->lock, flags);
581 
582 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
583 
584 	/* cancel scheduled setup */
585 	cancel_delayed_work_sync(&priv->delayed_setup_work);
586 	cancel_delayed_work_sync(&priv->delayed_write_work);
587 
588 	/* shutdown our urbs */
589 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
590 	usb_kill_urb(port->write_urb);
591 	usb_kill_urb(port->read_urb);
592 	usb_kill_urb(port->interrupt_in_urb);
593 }
594 
595 static int oti6858_tiocmset(struct tty_struct *tty,
596 				unsigned int set, unsigned int clear)
597 {
598 	struct usb_serial_port *port = tty->driver_data;
599 	struct oti6858_private *priv = usb_get_serial_port_data(port);
600 	unsigned long flags;
601 	u8 control;
602 
603 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
604 		__func__, set, clear);
605 
606 	/* FIXME: check if this is correct (active high/low) */
607 	spin_lock_irqsave(&priv->lock, flags);
608 	control = priv->pending_setup.control;
609 	if ((set & TIOCM_RTS) != 0)
610 		control |= CONTROL_RTS_HIGH;
611 	if ((set & TIOCM_DTR) != 0)
612 		control |= CONTROL_DTR_HIGH;
613 	if ((clear & TIOCM_RTS) != 0)
614 		control &= ~CONTROL_RTS_HIGH;
615 	if ((clear & TIOCM_DTR) != 0)
616 		control &= ~CONTROL_DTR_HIGH;
617 
618 	if (control != priv->pending_setup.control)
619 		priv->pending_setup.control = control;
620 
621 	spin_unlock_irqrestore(&priv->lock, flags);
622 	return 0;
623 }
624 
625 static int oti6858_tiocmget(struct tty_struct *tty)
626 {
627 	struct usb_serial_port *port = tty->driver_data;
628 	struct oti6858_private *priv = usb_get_serial_port_data(port);
629 	unsigned long flags;
630 	unsigned pin_state;
631 	unsigned result = 0;
632 
633 	spin_lock_irqsave(&priv->lock, flags);
634 	pin_state = priv->status.pin_state & PIN_MASK;
635 	spin_unlock_irqrestore(&priv->lock, flags);
636 
637 	/* FIXME: check if this is correct (active high/low) */
638 	if ((pin_state & PIN_RTS) != 0)
639 		result |= TIOCM_RTS;
640 	if ((pin_state & PIN_CTS) != 0)
641 		result |= TIOCM_CTS;
642 	if ((pin_state & PIN_DSR) != 0)
643 		result |= TIOCM_DSR;
644 	if ((pin_state & PIN_DTR) != 0)
645 		result |= TIOCM_DTR;
646 	if ((pin_state & PIN_RI) != 0)
647 		result |= TIOCM_RI;
648 	if ((pin_state & PIN_DCD) != 0)
649 		result |= TIOCM_CD;
650 
651 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
652 
653 	return result;
654 }
655 
656 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
657 {
658 	struct oti6858_private *priv = usb_get_serial_port_data(port);
659 	unsigned long flags;
660 	unsigned int prev, status;
661 	unsigned int changed;
662 
663 	spin_lock_irqsave(&priv->lock, flags);
664 	prev = priv->status.pin_state;
665 	spin_unlock_irqrestore(&priv->lock, flags);
666 
667 	while (1) {
668 		wait_event_interruptible(priv->intr_wait,
669 					priv->status.pin_state != prev);
670 		if (signal_pending(current))
671 			return -ERESTARTSYS;
672 
673 		spin_lock_irqsave(&priv->lock, flags);
674 		status = priv->status.pin_state & PIN_MASK;
675 		spin_unlock_irqrestore(&priv->lock, flags);
676 
677 		changed = prev ^ status;
678 		/* FIXME: check if this is correct (active high/low) */
679 		if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
680 		    ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
681 		    ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
682 		    ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
683 			return 0;
684 		prev = status;
685 	}
686 
687 	/* NOTREACHED */
688 	return 0;
689 }
690 
691 static int oti6858_ioctl(struct tty_struct *tty,
692 			unsigned int cmd, unsigned long arg)
693 {
694 	struct usb_serial_port *port = tty->driver_data;
695 
696 	dev_dbg(&port->dev, "%s(cmd = 0x%04x, arg = 0x%08lx)\n", __func__, cmd, arg);
697 
698 	switch (cmd) {
699 	case TIOCMIWAIT:
700 		dev_dbg(&port->dev, "%s(): TIOCMIWAIT\n", __func__);
701 		return wait_modem_info(port, arg);
702 	default:
703 		dev_dbg(&port->dev, "%s(): 0x%04x not supported\n", __func__, cmd);
704 		break;
705 	}
706 	return -ENOIOCTLCMD;
707 }
708 
709 static void oti6858_read_int_callback(struct urb *urb)
710 {
711 	struct usb_serial_port *port =  urb->context;
712 	struct oti6858_private *priv = usb_get_serial_port_data(port);
713 	int transient = 0, can_recv = 0, resubmit = 1;
714 	int status = urb->status;
715 
716 	switch (status) {
717 	case 0:
718 		/* success */
719 		break;
720 	case -ECONNRESET:
721 	case -ENOENT:
722 	case -ESHUTDOWN:
723 		/* this urb is terminated, clean up */
724 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
725 			__func__, status);
726 		return;
727 	default:
728 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
729 			__func__, status);
730 		break;
731 	}
732 
733 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
734 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
735 		unsigned long flags;
736 
737 		spin_lock_irqsave(&priv->lock, flags);
738 
739 		if (!priv->transient) {
740 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
741 				if (xs->rx_bytes_avail == 0) {
742 					priv->transient = 4;
743 					priv->setup_done = 0;
744 					resubmit = 0;
745 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
746 					schedule_delayed_work(&priv->delayed_setup_work, 0);
747 				}
748 			}
749 		} else {
750 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
751 				priv->transient = 0;
752 			} else if (!priv->setup_done) {
753 				resubmit = 0;
754 			} else if (--priv->transient == 0) {
755 				if (xs->rx_bytes_avail == 0) {
756 					priv->transient = 4;
757 					priv->setup_done = 0;
758 					resubmit = 0;
759 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
760 					schedule_delayed_work(&priv->delayed_setup_work, 0);
761 				}
762 			}
763 		}
764 
765 		if (!priv->transient) {
766 			if (xs->pin_state != priv->status.pin_state)
767 				wake_up_interruptible(&priv->intr_wait);
768 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
769 		}
770 
771 		if (!priv->transient && xs->rx_bytes_avail != 0) {
772 			can_recv = xs->rx_bytes_avail;
773 			priv->flags.read_urb_in_use = 1;
774 		}
775 
776 		transient = priv->transient;
777 		spin_unlock_irqrestore(&priv->lock, flags);
778 	}
779 
780 	if (can_recv) {
781 		int result;
782 
783 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
784 		if (result != 0) {
785 			priv->flags.read_urb_in_use = 0;
786 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
787 					" error %d\n", __func__, result);
788 		} else {
789 			resubmit = 0;
790 		}
791 	} else if (!transient) {
792 		unsigned long flags;
793 		int count;
794 
795 		spin_lock_irqsave(&port->lock, flags);
796 		count = kfifo_len(&port->write_fifo);
797 		spin_unlock_irqrestore(&port->lock, flags);
798 
799 		spin_lock_irqsave(&priv->lock, flags);
800 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
801 			schedule_delayed_work(&priv->delayed_write_work, 0);
802 			resubmit = 0;
803 		}
804 		spin_unlock_irqrestore(&priv->lock, flags);
805 	}
806 
807 	if (resubmit) {
808 		int result;
809 
810 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
811 		result = usb_submit_urb(urb, GFP_ATOMIC);
812 		if (result != 0) {
813 			dev_err(&urb->dev->dev,
814 					"%s(): usb_submit_urb() failed with"
815 					" error %d\n", __func__, result);
816 		}
817 	}
818 }
819 
820 static void oti6858_read_bulk_callback(struct urb *urb)
821 {
822 	struct usb_serial_port *port =  urb->context;
823 	struct oti6858_private *priv = usb_get_serial_port_data(port);
824 	struct tty_struct *tty;
825 	unsigned char *data = urb->transfer_buffer;
826 	unsigned long flags;
827 	int status = urb->status;
828 	int result;
829 
830 	spin_lock_irqsave(&priv->lock, flags);
831 	priv->flags.read_urb_in_use = 0;
832 	spin_unlock_irqrestore(&priv->lock, flags);
833 
834 	if (status != 0) {
835 		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
836 		return;
837 	}
838 
839 	tty = tty_port_tty_get(&port->port);
840 	if (tty != NULL && urb->actual_length > 0) {
841 		tty_insert_flip_string(tty, data, urb->actual_length);
842 		tty_flip_buffer_push(tty);
843 	}
844 	tty_kref_put(tty);
845 
846 	/* schedule the interrupt urb */
847 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
848 	if (result != 0 && result != -EPERM) {
849 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
850 				" error %d\n", __func__, result);
851 	}
852 }
853 
854 static void oti6858_write_bulk_callback(struct urb *urb)
855 {
856 	struct usb_serial_port *port =  urb->context;
857 	struct oti6858_private *priv = usb_get_serial_port_data(port);
858 	int status = urb->status;
859 	int result;
860 
861 	switch (status) {
862 	case 0:
863 		/* success */
864 		break;
865 	case -ECONNRESET:
866 	case -ENOENT:
867 	case -ESHUTDOWN:
868 		/* this urb is terminated, clean up */
869 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
870 		priv->flags.write_urb_in_use = 0;
871 		return;
872 	default:
873 		/* error in the urb, so we have to resubmit it */
874 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
875 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
876 
877 		port->write_urb->transfer_buffer_length = 1;
878 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
879 		if (result) {
880 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
881 					" error %d\n", __func__, result);
882 		} else {
883 			return;
884 		}
885 	}
886 
887 	priv->flags.write_urb_in_use = 0;
888 
889 	/* schedule the interrupt urb if we are still open */
890 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
891 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
892 	if (result != 0) {
893 		dev_err(&port->dev, "%s(): failed submitting int urb,"
894 					" error %d\n", __func__, result);
895 	}
896 }
897 
898 module_usb_serial_driver(serial_drivers, id_table);
899 
900 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
901 MODULE_AUTHOR(OTI6858_AUTHOR);
902 MODULE_VERSION(OTI6858_VERSION);
903 MODULE_LICENSE("GPL");
904