xref: /openbmc/linux/drivers/usb/serial/oti6858.c (revision 95e9fd10)
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 static bool debug;
70 
71 /* requests */
72 #define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
73 #define	OTI6858_REQ_T_GET_STATUS	0x01
74 
75 #define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
76 #define	OTI6858_REQ_T_SET_LINE		0x00
77 
78 #define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
79 #define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
80 
81 /* format of the control packet */
82 struct oti6858_control_pkt {
83 	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
84 #define OTI6858_MAX_BAUD_RATE	3000000
85 	u8	frame_fmt;
86 #define FMT_STOP_BITS_MASK	0xc0
87 #define FMT_STOP_BITS_1		0x00
88 #define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
89 #define FMT_PARITY_MASK		0x38
90 #define FMT_PARITY_NONE		0x00
91 #define FMT_PARITY_ODD		0x08
92 #define FMT_PARITY_EVEN		0x18
93 #define FMT_PARITY_MARK		0x28
94 #define FMT_PARITY_SPACE	0x38
95 #define FMT_DATA_BITS_MASK	0x03
96 #define FMT_DATA_BITS_5		0x00
97 #define FMT_DATA_BITS_6		0x01
98 #define FMT_DATA_BITS_7		0x02
99 #define FMT_DATA_BITS_8		0x03
100 	u8	something;	/* always equals 0x43 */
101 	u8	control;	/* settings of flow control lines */
102 #define CONTROL_MASK		0x0c
103 #define CONTROL_DTR_HIGH	0x08
104 #define CONTROL_RTS_HIGH	0x04
105 	u8	tx_status;
106 #define	TX_BUFFER_EMPTIED	0x09
107 	u8	pin_state;
108 #define PIN_MASK		0x3f
109 #define PIN_RTS			0x20	/* output pin */
110 #define PIN_CTS			0x10	/* input pin, active low */
111 #define PIN_DSR			0x08	/* input pin, active low */
112 #define PIN_DTR			0x04	/* output pin */
113 #define PIN_RI			0x02	/* input pin, active low */
114 #define PIN_DCD			0x01	/* input pin, active low */
115 	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
116 };
117 
118 #define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
119 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
120 	(((a)->divisor == (priv)->pending_setup.divisor) \
121 	  && ((a)->control == (priv)->pending_setup.control) \
122 	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
123 
124 /* function prototypes */
125 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
126 static void oti6858_close(struct usb_serial_port *port);
127 static void oti6858_set_termios(struct tty_struct *tty,
128 			struct usb_serial_port *port, struct ktermios *old);
129 static void oti6858_init_termios(struct tty_struct *tty);
130 static int oti6858_ioctl(struct tty_struct *tty,
131 			unsigned int cmd, unsigned long arg);
132 static void oti6858_read_int_callback(struct urb *urb);
133 static void oti6858_read_bulk_callback(struct urb *urb);
134 static void oti6858_write_bulk_callback(struct urb *urb);
135 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
136 			const unsigned char *buf, int count);
137 static int oti6858_write_room(struct tty_struct *tty);
138 static int oti6858_chars_in_buffer(struct tty_struct *tty);
139 static int oti6858_tiocmget(struct tty_struct *tty);
140 static int oti6858_tiocmset(struct tty_struct *tty,
141 				unsigned int set, unsigned int clear);
142 static int oti6858_startup(struct usb_serial *serial);
143 static void oti6858_release(struct usb_serial *serial);
144 
145 /* device info */
146 static struct usb_serial_driver oti6858_device = {
147 	.driver = {
148 		.owner =	THIS_MODULE,
149 		.name =		"oti6858",
150 	},
151 	.id_table =		id_table,
152 	.num_ports =		1,
153 	.open =			oti6858_open,
154 	.close =		oti6858_close,
155 	.write =		oti6858_write,
156 	.ioctl =		oti6858_ioctl,
157 	.set_termios =		oti6858_set_termios,
158 	.init_termios = 	oti6858_init_termios,
159 	.tiocmget =		oti6858_tiocmget,
160 	.tiocmset =		oti6858_tiocmset,
161 	.read_bulk_callback =	oti6858_read_bulk_callback,
162 	.read_int_callback =	oti6858_read_int_callback,
163 	.write_bulk_callback =	oti6858_write_bulk_callback,
164 	.write_room =		oti6858_write_room,
165 	.chars_in_buffer =	oti6858_chars_in_buffer,
166 	.attach =		oti6858_startup,
167 	.release =		oti6858_release,
168 };
169 
170 static struct usb_serial_driver * const serial_drivers[] = {
171 	&oti6858_device, NULL
172 };
173 
174 struct oti6858_private {
175 	spinlock_t lock;
176 
177 	struct oti6858_control_pkt status;
178 
179 	struct {
180 		u8 read_urb_in_use;
181 		u8 write_urb_in_use;
182 	} flags;
183 	struct delayed_work delayed_write_work;
184 
185 	struct {
186 		__le16 divisor;
187 		u8 frame_fmt;
188 		u8 control;
189 	} pending_setup;
190 	u8 transient;
191 	u8 setup_done;
192 	struct delayed_work delayed_setup_work;
193 
194 	wait_queue_head_t intr_wait;
195 	struct usb_serial_port *port;   /* USB port with which associated */
196 };
197 
198 static void setup_line(struct work_struct *work)
199 {
200 	struct oti6858_private *priv = container_of(work,
201 			struct oti6858_private, delayed_setup_work.work);
202 	struct usb_serial_port *port = priv->port;
203 	struct oti6858_control_pkt *new_setup;
204 	unsigned long flags;
205 	int result;
206 
207 	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
208 	if (new_setup == NULL) {
209 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
210 		/* we will try again */
211 		schedule_delayed_work(&priv->delayed_setup_work,
212 						msecs_to_jiffies(2));
213 		return;
214 	}
215 
216 	result = usb_control_msg(port->serial->dev,
217 				usb_rcvctrlpipe(port->serial->dev, 0),
218 				OTI6858_REQ_T_GET_STATUS,
219 				OTI6858_REQ_GET_STATUS,
220 				0, 0,
221 				new_setup, OTI6858_CTRL_PKT_SIZE,
222 				100);
223 
224 	if (result != OTI6858_CTRL_PKT_SIZE) {
225 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
226 		kfree(new_setup);
227 		/* we will try again */
228 		schedule_delayed_work(&priv->delayed_setup_work,
229 							msecs_to_jiffies(2));
230 		return;
231 	}
232 
233 	spin_lock_irqsave(&priv->lock, flags);
234 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
235 		new_setup->divisor = priv->pending_setup.divisor;
236 		new_setup->control = priv->pending_setup.control;
237 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
238 
239 		spin_unlock_irqrestore(&priv->lock, flags);
240 		result = usb_control_msg(port->serial->dev,
241 					usb_sndctrlpipe(port->serial->dev, 0),
242 					OTI6858_REQ_T_SET_LINE,
243 					OTI6858_REQ_SET_LINE,
244 					0, 0,
245 					new_setup, OTI6858_CTRL_PKT_SIZE,
246 					100);
247 	} else {
248 		spin_unlock_irqrestore(&priv->lock, flags);
249 		result = 0;
250 	}
251 	kfree(new_setup);
252 
253 	spin_lock_irqsave(&priv->lock, flags);
254 	if (result != OTI6858_CTRL_PKT_SIZE)
255 		priv->transient = 0;
256 	priv->setup_done = 1;
257 	spin_unlock_irqrestore(&priv->lock, flags);
258 
259 	dbg("%s(): submitting interrupt urb", __func__);
260 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
261 	if (result != 0) {
262 		dev_err(&port->dev, "%s(): usb_submit_urb() failed"
263 				" with error %d\n", __func__, result);
264 	}
265 }
266 
267 static void send_data(struct work_struct *work)
268 {
269 	struct oti6858_private *priv = container_of(work,
270 			struct oti6858_private, delayed_write_work.work);
271 	struct usb_serial_port *port = priv->port;
272 	int count = 0, result;
273 	unsigned long flags;
274 	u8 *allow;
275 
276 	spin_lock_irqsave(&priv->lock, flags);
277 	if (priv->flags.write_urb_in_use) {
278 		spin_unlock_irqrestore(&priv->lock, flags);
279 		schedule_delayed_work(&priv->delayed_write_work,
280 						msecs_to_jiffies(2));
281 		return;
282 	}
283 	priv->flags.write_urb_in_use = 1;
284 	spin_unlock_irqrestore(&priv->lock, flags);
285 
286 	spin_lock_irqsave(&port->lock, flags);
287 	count = kfifo_len(&port->write_fifo);
288 	spin_unlock_irqrestore(&port->lock, flags);
289 
290 	if (count > port->bulk_out_size)
291 		count = port->bulk_out_size;
292 
293 	if (count != 0) {
294 		allow = kmalloc(1, GFP_KERNEL);
295 		if (!allow) {
296 			dev_err_console(port, "%s(): kmalloc failed\n",
297 					__func__);
298 			return;
299 		}
300 		result = usb_control_msg(port->serial->dev,
301 				usb_rcvctrlpipe(port->serial->dev, 0),
302 				OTI6858_REQ_T_CHECK_TXBUFF,
303 				OTI6858_REQ_CHECK_TXBUFF,
304 				count, 0, allow, 1, 100);
305 		if (result != 1 || *allow != 0)
306 			count = 0;
307 		kfree(allow);
308 	}
309 
310 	if (count == 0) {
311 		priv->flags.write_urb_in_use = 0;
312 
313 		dbg("%s(): submitting interrupt urb", __func__);
314 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
315 		if (result != 0) {
316 			dev_err(&port->dev, "%s(): usb_submit_urb() failed"
317 				" with error %d\n", __func__, result);
318 		}
319 		return;
320 	}
321 
322 	count = kfifo_out_locked(&port->write_fifo,
323 					port->write_urb->transfer_buffer,
324 					count, &port->lock);
325 	port->write_urb->transfer_buffer_length = count;
326 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
327 	if (result != 0) {
328 		dev_err_console(port, "%s(): usb_submit_urb() failed"
329 			       " with error %d\n", __func__, result);
330 		priv->flags.write_urb_in_use = 0;
331 	}
332 
333 	usb_serial_port_softint(port);
334 }
335 
336 static int oti6858_startup(struct usb_serial *serial)
337 {
338 	struct usb_serial_port *port = serial->port[0];
339 	struct oti6858_private *priv;
340 	int i;
341 
342 	for (i = 0; i < serial->num_ports; ++i) {
343 		priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
344 		if (!priv)
345 			break;
346 
347 		spin_lock_init(&priv->lock);
348 		init_waitqueue_head(&priv->intr_wait);
349 /*		INIT_WORK(&priv->setup_work, setup_line, serial->port[i]); */
350 /*		INIT_WORK(&priv->write_work, send_data, serial->port[i]); */
351 		priv->port = port;
352 		INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
353 		INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
354 
355 		usb_set_serial_port_data(serial->port[i], priv);
356 	}
357 	if (i == serial->num_ports)
358 		return 0;
359 
360 	for (--i; i >= 0; --i) {
361 		priv = usb_get_serial_port_data(serial->port[i]);
362 		kfree(priv);
363 		usb_set_serial_port_data(serial->port[i], NULL);
364 	}
365 	return -ENOMEM;
366 }
367 
368 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
369 			const unsigned char *buf, int count)
370 {
371 	if (!count)
372 		return count;
373 
374 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
375 
376 	return count;
377 }
378 
379 static int oti6858_write_room(struct tty_struct *tty)
380 {
381 	struct usb_serial_port *port = tty->driver_data;
382 	int room = 0;
383 	unsigned long flags;
384 
385 	spin_lock_irqsave(&port->lock, flags);
386 	room = kfifo_avail(&port->write_fifo);
387 	spin_unlock_irqrestore(&port->lock, flags);
388 
389 	return room;
390 }
391 
392 static int oti6858_chars_in_buffer(struct tty_struct *tty)
393 {
394 	struct usb_serial_port *port = tty->driver_data;
395 	int chars = 0;
396 	unsigned long flags;
397 
398 	spin_lock_irqsave(&port->lock, flags);
399 	chars = kfifo_len(&port->write_fifo);
400 	spin_unlock_irqrestore(&port->lock, flags);
401 
402 	return chars;
403 }
404 
405 static void oti6858_init_termios(struct tty_struct *tty)
406 {
407 	*(tty->termios) = tty_std_termios;
408 	tty->termios->c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
409 	tty->termios->c_ispeed = 38400;
410 	tty->termios->c_ospeed = 38400;
411 }
412 
413 static void oti6858_set_termios(struct tty_struct *tty,
414 		struct usb_serial_port *port, struct ktermios *old_termios)
415 {
416 	struct oti6858_private *priv = usb_get_serial_port_data(port);
417 	unsigned long flags;
418 	unsigned int cflag;
419 	u8 frame_fmt, control;
420 	__le16 divisor;
421 	int br;
422 
423 	if (!tty) {
424 		dbg("%s(): no tty structures", __func__);
425 		return;
426 	}
427 
428 	cflag = tty->termios->c_cflag;
429 
430 	spin_lock_irqsave(&priv->lock, flags);
431 	divisor = priv->pending_setup.divisor;
432 	frame_fmt = priv->pending_setup.frame_fmt;
433 	control = priv->pending_setup.control;
434 	spin_unlock_irqrestore(&priv->lock, flags);
435 
436 	frame_fmt &= ~FMT_DATA_BITS_MASK;
437 	switch (cflag & CSIZE) {
438 	case CS5:
439 		frame_fmt |= FMT_DATA_BITS_5;
440 		break;
441 	case CS6:
442 		frame_fmt |= FMT_DATA_BITS_6;
443 		break;
444 	case CS7:
445 		frame_fmt |= FMT_DATA_BITS_7;
446 		break;
447 	default:
448 	case CS8:
449 		frame_fmt |= FMT_DATA_BITS_8;
450 		break;
451 	}
452 
453 	/* manufacturer claims that this device can work with baud rates
454 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
455 	 * guarantee that any other baud rate will work (especially
456 	 * the higher ones)
457 	 */
458 	br = tty_get_baud_rate(tty);
459 	if (br == 0) {
460 		divisor = 0;
461 	} else {
462 		int real_br;
463 		int new_divisor;
464 		br = min(br, OTI6858_MAX_BAUD_RATE);
465 
466 		new_divisor = (96000000 + 8 * br) / (16 * br);
467 		real_br = 96000000 / (16 * new_divisor);
468 		divisor = cpu_to_le16(new_divisor);
469 		tty_encode_baud_rate(tty, real_br, real_br);
470 	}
471 
472 	frame_fmt &= ~FMT_STOP_BITS_MASK;
473 	if ((cflag & CSTOPB) != 0)
474 		frame_fmt |= FMT_STOP_BITS_2;
475 	else
476 		frame_fmt |= FMT_STOP_BITS_1;
477 
478 	frame_fmt &= ~FMT_PARITY_MASK;
479 	if ((cflag & PARENB) != 0) {
480 		if ((cflag & PARODD) != 0)
481 			frame_fmt |= FMT_PARITY_ODD;
482 		else
483 			frame_fmt |= FMT_PARITY_EVEN;
484 	} else {
485 		frame_fmt |= FMT_PARITY_NONE;
486 	}
487 
488 	control &= ~CONTROL_MASK;
489 	if ((cflag & CRTSCTS) != 0)
490 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
491 
492 	/* change control lines if we are switching to or from B0 */
493 	/* FIXME:
494 	spin_lock_irqsave(&priv->lock, flags);
495 	control = priv->line_control;
496 	if ((cflag & CBAUD) == B0)
497 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
498 	else
499 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
500 	if (control != priv->line_control) {
501 		control = priv->line_control;
502 		spin_unlock_irqrestore(&priv->lock, flags);
503 		set_control_lines(serial->dev, control);
504 	} else {
505 		spin_unlock_irqrestore(&priv->lock, flags);
506 	}
507 	*/
508 
509 	spin_lock_irqsave(&priv->lock, flags);
510 	if (divisor != priv->pending_setup.divisor
511 			|| control != priv->pending_setup.control
512 			|| frame_fmt != priv->pending_setup.frame_fmt) {
513 		priv->pending_setup.divisor = divisor;
514 		priv->pending_setup.control = control;
515 		priv->pending_setup.frame_fmt = frame_fmt;
516 	}
517 	spin_unlock_irqrestore(&priv->lock, flags);
518 }
519 
520 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
521 {
522 	struct oti6858_private *priv = usb_get_serial_port_data(port);
523 	struct ktermios tmp_termios;
524 	struct usb_serial *serial = port->serial;
525 	struct oti6858_control_pkt *buf;
526 	unsigned long flags;
527 	int result;
528 
529 	usb_clear_halt(serial->dev, port->write_urb->pipe);
530 	usb_clear_halt(serial->dev, port->read_urb->pipe);
531 
532 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
533 	if (buf == NULL) {
534 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
535 		return -ENOMEM;
536 	}
537 
538 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
539 				OTI6858_REQ_T_GET_STATUS,
540 				OTI6858_REQ_GET_STATUS,
541 				0, 0,
542 				buf, OTI6858_CTRL_PKT_SIZE,
543 				100);
544 	if (result != OTI6858_CTRL_PKT_SIZE) {
545 		/* assume default (after power-on reset) values */
546 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
547 		buf->frame_fmt = 0x03;	/* 8N1 */
548 		buf->something = 0x43;
549 		buf->control = 0x4c;	/* DTR, RTS */
550 		buf->tx_status = 0x00;
551 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
552 		buf->rx_bytes_avail = 0x00;
553 	}
554 
555 	spin_lock_irqsave(&priv->lock, flags);
556 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
557 	priv->pending_setup.divisor = buf->divisor;
558 	priv->pending_setup.frame_fmt = buf->frame_fmt;
559 	priv->pending_setup.control = buf->control;
560 	spin_unlock_irqrestore(&priv->lock, flags);
561 	kfree(buf);
562 
563 	dbg("%s(): submitting interrupt urb", __func__);
564 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
565 	if (result != 0) {
566 		dev_err(&port->dev, "%s(): usb_submit_urb() failed"
567 			       " with error %d\n", __func__, result);
568 		oti6858_close(port);
569 		return result;
570 	}
571 
572 	/* setup termios */
573 	if (tty)
574 		oti6858_set_termios(tty, port, &tmp_termios);
575 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
576 	return 0;
577 }
578 
579 static void oti6858_close(struct usb_serial_port *port)
580 {
581 	struct oti6858_private *priv = usb_get_serial_port_data(port);
582 	unsigned long flags;
583 
584 	spin_lock_irqsave(&port->lock, flags);
585 	/* clear out any remaining data in the buffer */
586 	kfifo_reset_out(&port->write_fifo);
587 	spin_unlock_irqrestore(&port->lock, flags);
588 
589 	dbg("%s(): after buf_clear()", __func__);
590 
591 	/* cancel scheduled setup */
592 	cancel_delayed_work_sync(&priv->delayed_setup_work);
593 	cancel_delayed_work_sync(&priv->delayed_write_work);
594 
595 	/* shutdown our urbs */
596 	dbg("%s(): shutting down urbs", __func__);
597 	usb_kill_urb(port->write_urb);
598 	usb_kill_urb(port->read_urb);
599 	usb_kill_urb(port->interrupt_in_urb);
600 }
601 
602 static int oti6858_tiocmset(struct tty_struct *tty,
603 				unsigned int set, unsigned int clear)
604 {
605 	struct usb_serial_port *port = tty->driver_data;
606 	struct oti6858_private *priv = usb_get_serial_port_data(port);
607 	unsigned long flags;
608 	u8 control;
609 
610 	dbg("%s(port = %d, set = 0x%08x, clear = 0x%08x)",
611 				__func__, port->number, set, clear);
612 
613 	/* FIXME: check if this is correct (active high/low) */
614 	spin_lock_irqsave(&priv->lock, flags);
615 	control = priv->pending_setup.control;
616 	if ((set & TIOCM_RTS) != 0)
617 		control |= CONTROL_RTS_HIGH;
618 	if ((set & TIOCM_DTR) != 0)
619 		control |= CONTROL_DTR_HIGH;
620 	if ((clear & TIOCM_RTS) != 0)
621 		control &= ~CONTROL_RTS_HIGH;
622 	if ((clear & TIOCM_DTR) != 0)
623 		control &= ~CONTROL_DTR_HIGH;
624 
625 	if (control != priv->pending_setup.control)
626 		priv->pending_setup.control = control;
627 
628 	spin_unlock_irqrestore(&priv->lock, flags);
629 	return 0;
630 }
631 
632 static int oti6858_tiocmget(struct tty_struct *tty)
633 {
634 	struct usb_serial_port *port = tty->driver_data;
635 	struct oti6858_private *priv = usb_get_serial_port_data(port);
636 	unsigned long flags;
637 	unsigned pin_state;
638 	unsigned result = 0;
639 
640 	spin_lock_irqsave(&priv->lock, flags);
641 	pin_state = priv->status.pin_state & PIN_MASK;
642 	spin_unlock_irqrestore(&priv->lock, flags);
643 
644 	/* FIXME: check if this is correct (active high/low) */
645 	if ((pin_state & PIN_RTS) != 0)
646 		result |= TIOCM_RTS;
647 	if ((pin_state & PIN_CTS) != 0)
648 		result |= TIOCM_CTS;
649 	if ((pin_state & PIN_DSR) != 0)
650 		result |= TIOCM_DSR;
651 	if ((pin_state & PIN_DTR) != 0)
652 		result |= TIOCM_DTR;
653 	if ((pin_state & PIN_RI) != 0)
654 		result |= TIOCM_RI;
655 	if ((pin_state & PIN_DCD) != 0)
656 		result |= TIOCM_CD;
657 
658 	dbg("%s() = 0x%08x", __func__, result);
659 
660 	return result;
661 }
662 
663 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
664 {
665 	struct oti6858_private *priv = usb_get_serial_port_data(port);
666 	unsigned long flags;
667 	unsigned int prev, status;
668 	unsigned int changed;
669 
670 	spin_lock_irqsave(&priv->lock, flags);
671 	prev = priv->status.pin_state;
672 	spin_unlock_irqrestore(&priv->lock, flags);
673 
674 	while (1) {
675 		wait_event_interruptible(priv->intr_wait,
676 					priv->status.pin_state != prev);
677 		if (signal_pending(current))
678 			return -ERESTARTSYS;
679 
680 		spin_lock_irqsave(&priv->lock, flags);
681 		status = priv->status.pin_state & PIN_MASK;
682 		spin_unlock_irqrestore(&priv->lock, flags);
683 
684 		changed = prev ^ status;
685 		/* FIXME: check if this is correct (active high/low) */
686 		if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
687 		    ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
688 		    ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
689 		    ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
690 			return 0;
691 		prev = status;
692 	}
693 
694 	/* NOTREACHED */
695 	return 0;
696 }
697 
698 static int oti6858_ioctl(struct tty_struct *tty,
699 			unsigned int cmd, unsigned long arg)
700 {
701 	struct usb_serial_port *port = tty->driver_data;
702 
703 	dbg("%s(port = %d, cmd = 0x%04x, arg = 0x%08lx)",
704 				__func__, port->number, cmd, arg);
705 
706 	switch (cmd) {
707 	case TIOCMIWAIT:
708 		dbg("%s(): TIOCMIWAIT", __func__);
709 		return wait_modem_info(port, arg);
710 	default:
711 		dbg("%s(): 0x%04x not supported", __func__, cmd);
712 		break;
713 	}
714 	return -ENOIOCTLCMD;
715 }
716 
717 
718 static void oti6858_release(struct usb_serial *serial)
719 {
720 	int i;
721 
722 	for (i = 0; i < serial->num_ports; ++i)
723 		kfree(usb_get_serial_port_data(serial->port[i]));
724 }
725 
726 static void oti6858_read_int_callback(struct urb *urb)
727 {
728 	struct usb_serial_port *port =  urb->context;
729 	struct oti6858_private *priv = usb_get_serial_port_data(port);
730 	int transient = 0, can_recv = 0, resubmit = 1;
731 	int status = urb->status;
732 
733 	switch (status) {
734 	case 0:
735 		/* success */
736 		break;
737 	case -ECONNRESET:
738 	case -ENOENT:
739 	case -ESHUTDOWN:
740 		/* this urb is terminated, clean up */
741 		dbg("%s(): urb shutting down with status: %d",
742 					__func__, status);
743 		return;
744 	default:
745 		dbg("%s(): nonzero urb status received: %d",
746 					__func__, status);
747 		break;
748 	}
749 
750 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
751 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
752 		unsigned long flags;
753 
754 		spin_lock_irqsave(&priv->lock, flags);
755 
756 		if (!priv->transient) {
757 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
758 				if (xs->rx_bytes_avail == 0) {
759 					priv->transient = 4;
760 					priv->setup_done = 0;
761 					resubmit = 0;
762 					dbg("%s(): scheduling setup_line()",
763 					    __func__);
764 					schedule_delayed_work(&priv->delayed_setup_work, 0);
765 				}
766 			}
767 		} else {
768 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
769 				priv->transient = 0;
770 			} else if (!priv->setup_done) {
771 				resubmit = 0;
772 			} else if (--priv->transient == 0) {
773 				if (xs->rx_bytes_avail == 0) {
774 					priv->transient = 4;
775 					priv->setup_done = 0;
776 					resubmit = 0;
777 					dbg("%s(): scheduling setup_line()",
778 					    __func__);
779 					schedule_delayed_work(&priv->delayed_setup_work, 0);
780 				}
781 			}
782 		}
783 
784 		if (!priv->transient) {
785 			if (xs->pin_state != priv->status.pin_state)
786 				wake_up_interruptible(&priv->intr_wait);
787 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
788 		}
789 
790 		if (!priv->transient && xs->rx_bytes_avail != 0) {
791 			can_recv = xs->rx_bytes_avail;
792 			priv->flags.read_urb_in_use = 1;
793 		}
794 
795 		transient = priv->transient;
796 		spin_unlock_irqrestore(&priv->lock, flags);
797 	}
798 
799 	if (can_recv) {
800 		int result;
801 
802 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
803 		if (result != 0) {
804 			priv->flags.read_urb_in_use = 0;
805 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
806 					" error %d\n", __func__, result);
807 		} else {
808 			resubmit = 0;
809 		}
810 	} else if (!transient) {
811 		unsigned long flags;
812 		int count;
813 
814 		spin_lock_irqsave(&port->lock, flags);
815 		count = kfifo_len(&port->write_fifo);
816 		spin_unlock_irqrestore(&port->lock, flags);
817 
818 		spin_lock_irqsave(&priv->lock, flags);
819 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
820 			schedule_delayed_work(&priv->delayed_write_work, 0);
821 			resubmit = 0;
822 		}
823 		spin_unlock_irqrestore(&priv->lock, flags);
824 	}
825 
826 	if (resubmit) {
827 		int result;
828 
829 /*		dbg("%s(): submitting interrupt urb", __func__); */
830 		result = usb_submit_urb(urb, GFP_ATOMIC);
831 		if (result != 0) {
832 			dev_err(&urb->dev->dev,
833 					"%s(): usb_submit_urb() failed with"
834 					" error %d\n", __func__, result);
835 		}
836 	}
837 }
838 
839 static void oti6858_read_bulk_callback(struct urb *urb)
840 {
841 	struct usb_serial_port *port =  urb->context;
842 	struct oti6858_private *priv = usb_get_serial_port_data(port);
843 	struct tty_struct *tty;
844 	unsigned char *data = urb->transfer_buffer;
845 	unsigned long flags;
846 	int status = urb->status;
847 	int result;
848 
849 	spin_lock_irqsave(&priv->lock, flags);
850 	priv->flags.read_urb_in_use = 0;
851 	spin_unlock_irqrestore(&priv->lock, flags);
852 
853 	if (status != 0) {
854 		dbg("%s(): unable to handle the error, exiting", __func__);
855 		return;
856 	}
857 
858 	tty = tty_port_tty_get(&port->port);
859 	if (tty != NULL && urb->actual_length > 0) {
860 		tty_insert_flip_string(tty, data, urb->actual_length);
861 		tty_flip_buffer_push(tty);
862 	}
863 	tty_kref_put(tty);
864 
865 	/* schedule the interrupt urb */
866 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
867 	if (result != 0 && result != -EPERM) {
868 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
869 				" error %d\n", __func__, result);
870 	}
871 }
872 
873 static void oti6858_write_bulk_callback(struct urb *urb)
874 {
875 	struct usb_serial_port *port =  urb->context;
876 	struct oti6858_private *priv = usb_get_serial_port_data(port);
877 	int status = urb->status;
878 	int result;
879 
880 	switch (status) {
881 	case 0:
882 		/* success */
883 		break;
884 	case -ECONNRESET:
885 	case -ENOENT:
886 	case -ESHUTDOWN:
887 		/* this urb is terminated, clean up */
888 		dbg("%s(): urb shutting down with status: %d",
889 					__func__, status);
890 		priv->flags.write_urb_in_use = 0;
891 		return;
892 	default:
893 		/* error in the urb, so we have to resubmit it */
894 		dbg("%s(): nonzero write bulk status received: %d",
895 					__func__, status);
896 		dbg("%s(): overflow in write", __func__);
897 
898 		port->write_urb->transfer_buffer_length = 1;
899 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
900 		if (result) {
901 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
902 					" error %d\n", __func__, result);
903 		} else {
904 			return;
905 		}
906 	}
907 
908 	priv->flags.write_urb_in_use = 0;
909 
910 	/* schedule the interrupt urb if we are still open */
911 	dbg("%s(): submitting interrupt urb", __func__);
912 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
913 	if (result != 0) {
914 		dev_err(&port->dev, "%s(): failed submitting int urb,"
915 					" error %d\n", __func__, result);
916 	}
917 }
918 
919 module_usb_serial_driver(serial_drivers, id_table);
920 
921 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
922 MODULE_AUTHOR(OTI6858_AUTHOR);
923 MODULE_VERSION(OTI6858_VERSION);
924 MODULE_LICENSE("GPL");
925 
926 module_param(debug, bool, S_IRUGO | S_IWUSR);
927 MODULE_PARM_DESC(debug, "enable debug output");
928 
929