xref: /linux/drivers/usb/serial/oti6858.c (revision c75c5ab575af7db707689cdbb5a5c458e9a034bb)
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 
61 static const struct usb_device_id id_table[] = {
62 	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
63 	{ }
64 };
65 
66 MODULE_DEVICE_TABLE(usb, id_table);
67 
68 /* requests */
69 #define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
70 #define	OTI6858_REQ_T_GET_STATUS	0x01
71 
72 #define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
73 #define	OTI6858_REQ_T_SET_LINE		0x00
74 
75 #define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
76 #define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
77 
78 /* format of the control packet */
79 struct oti6858_control_pkt {
80 	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
81 #define OTI6858_MAX_BAUD_RATE	3000000
82 	u8	frame_fmt;
83 #define FMT_STOP_BITS_MASK	0xc0
84 #define FMT_STOP_BITS_1		0x00
85 #define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
86 #define FMT_PARITY_MASK		0x38
87 #define FMT_PARITY_NONE		0x00
88 #define FMT_PARITY_ODD		0x08
89 #define FMT_PARITY_EVEN		0x18
90 #define FMT_PARITY_MARK		0x28
91 #define FMT_PARITY_SPACE	0x38
92 #define FMT_DATA_BITS_MASK	0x03
93 #define FMT_DATA_BITS_5		0x00
94 #define FMT_DATA_BITS_6		0x01
95 #define FMT_DATA_BITS_7		0x02
96 #define FMT_DATA_BITS_8		0x03
97 	u8	something;	/* always equals 0x43 */
98 	u8	control;	/* settings of flow control lines */
99 #define CONTROL_MASK		0x0c
100 #define CONTROL_DTR_HIGH	0x08
101 #define CONTROL_RTS_HIGH	0x04
102 	u8	tx_status;
103 #define	TX_BUFFER_EMPTIED	0x09
104 	u8	pin_state;
105 #define PIN_MASK		0x3f
106 #define PIN_RTS			0x20	/* output pin */
107 #define PIN_CTS			0x10	/* input pin, active low */
108 #define PIN_DSR			0x08	/* input pin, active low */
109 #define PIN_DTR			0x04	/* output pin */
110 #define PIN_RI			0x02	/* input pin, active low */
111 #define PIN_DCD			0x01	/* input pin, active low */
112 	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
113 };
114 
115 #define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
116 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
117 	(((a)->divisor == (priv)->pending_setup.divisor) \
118 	  && ((a)->control == (priv)->pending_setup.control) \
119 	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
120 
121 /* function prototypes */
122 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
123 static void oti6858_close(struct usb_serial_port *port);
124 static void oti6858_set_termios(struct tty_struct *tty,
125 			struct usb_serial_port *port, struct ktermios *old);
126 static void oti6858_init_termios(struct tty_struct *tty);
127 static int oti6858_ioctl(struct tty_struct *tty,
128 			unsigned int cmd, unsigned long arg);
129 static void oti6858_read_int_callback(struct urb *urb);
130 static void oti6858_read_bulk_callback(struct urb *urb);
131 static void oti6858_write_bulk_callback(struct urb *urb);
132 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
133 			const unsigned char *buf, int count);
134 static int oti6858_write_room(struct tty_struct *tty);
135 static int oti6858_chars_in_buffer(struct tty_struct *tty);
136 static int oti6858_tiocmget(struct tty_struct *tty);
137 static int oti6858_tiocmset(struct tty_struct *tty,
138 				unsigned int set, unsigned int clear);
139 static int oti6858_port_probe(struct usb_serial_port *port);
140 static int oti6858_port_remove(struct usb_serial_port *port);
141 
142 /* device info */
143 static struct usb_serial_driver oti6858_device = {
144 	.driver = {
145 		.owner =	THIS_MODULE,
146 		.name =		"oti6858",
147 	},
148 	.id_table =		id_table,
149 	.num_ports =		1,
150 	.open =			oti6858_open,
151 	.close =		oti6858_close,
152 	.write =		oti6858_write,
153 	.ioctl =		oti6858_ioctl,
154 	.set_termios =		oti6858_set_termios,
155 	.init_termios = 	oti6858_init_termios,
156 	.tiocmget =		oti6858_tiocmget,
157 	.tiocmset =		oti6858_tiocmset,
158 	.read_bulk_callback =	oti6858_read_bulk_callback,
159 	.read_int_callback =	oti6858_read_int_callback,
160 	.write_bulk_callback =	oti6858_write_bulk_callback,
161 	.write_room =		oti6858_write_room,
162 	.chars_in_buffer =	oti6858_chars_in_buffer,
163 	.port_probe =		oti6858_port_probe,
164 	.port_remove =		oti6858_port_remove,
165 };
166 
167 static struct usb_serial_driver * const serial_drivers[] = {
168 	&oti6858_device, NULL
169 };
170 
171 struct oti6858_private {
172 	spinlock_t lock;
173 
174 	struct oti6858_control_pkt status;
175 
176 	struct {
177 		u8 read_urb_in_use;
178 		u8 write_urb_in_use;
179 	} flags;
180 	struct delayed_work delayed_write_work;
181 
182 	struct {
183 		__le16 divisor;
184 		u8 frame_fmt;
185 		u8 control;
186 	} pending_setup;
187 	u8 transient;
188 	u8 setup_done;
189 	struct delayed_work delayed_setup_work;
190 
191 	struct usb_serial_port *port;   /* USB port with which associated */
192 };
193 
194 static void setup_line(struct work_struct *work)
195 {
196 	struct oti6858_private *priv = container_of(work,
197 			struct oti6858_private, delayed_setup_work.work);
198 	struct usb_serial_port *port = priv->port;
199 	struct oti6858_control_pkt *new_setup;
200 	unsigned long flags;
201 	int result;
202 
203 	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
204 	if (new_setup == NULL) {
205 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
206 		/* we will try again */
207 		schedule_delayed_work(&priv->delayed_setup_work,
208 						msecs_to_jiffies(2));
209 		return;
210 	}
211 
212 	result = usb_control_msg(port->serial->dev,
213 				usb_rcvctrlpipe(port->serial->dev, 0),
214 				OTI6858_REQ_T_GET_STATUS,
215 				OTI6858_REQ_GET_STATUS,
216 				0, 0,
217 				new_setup, OTI6858_CTRL_PKT_SIZE,
218 				100);
219 
220 	if (result != OTI6858_CTRL_PKT_SIZE) {
221 		dev_err(&port->dev, "%s(): error reading status\n", __func__);
222 		kfree(new_setup);
223 		/* we will try again */
224 		schedule_delayed_work(&priv->delayed_setup_work,
225 							msecs_to_jiffies(2));
226 		return;
227 	}
228 
229 	spin_lock_irqsave(&priv->lock, flags);
230 	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
231 		new_setup->divisor = priv->pending_setup.divisor;
232 		new_setup->control = priv->pending_setup.control;
233 		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
234 
235 		spin_unlock_irqrestore(&priv->lock, flags);
236 		result = usb_control_msg(port->serial->dev,
237 					usb_sndctrlpipe(port->serial->dev, 0),
238 					OTI6858_REQ_T_SET_LINE,
239 					OTI6858_REQ_SET_LINE,
240 					0, 0,
241 					new_setup, OTI6858_CTRL_PKT_SIZE,
242 					100);
243 	} else {
244 		spin_unlock_irqrestore(&priv->lock, flags);
245 		result = 0;
246 	}
247 	kfree(new_setup);
248 
249 	spin_lock_irqsave(&priv->lock, flags);
250 	if (result != OTI6858_CTRL_PKT_SIZE)
251 		priv->transient = 0;
252 	priv->setup_done = 1;
253 	spin_unlock_irqrestore(&priv->lock, flags);
254 
255 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
256 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
257 	if (result != 0) {
258 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
259 			__func__, result);
260 	}
261 }
262 
263 static void send_data(struct work_struct *work)
264 {
265 	struct oti6858_private *priv = container_of(work,
266 			struct oti6858_private, delayed_write_work.work);
267 	struct usb_serial_port *port = priv->port;
268 	int count = 0, result;
269 	unsigned long flags;
270 	u8 *allow;
271 
272 	spin_lock_irqsave(&priv->lock, flags);
273 	if (priv->flags.write_urb_in_use) {
274 		spin_unlock_irqrestore(&priv->lock, flags);
275 		schedule_delayed_work(&priv->delayed_write_work,
276 						msecs_to_jiffies(2));
277 		return;
278 	}
279 	priv->flags.write_urb_in_use = 1;
280 	spin_unlock_irqrestore(&priv->lock, flags);
281 
282 	spin_lock_irqsave(&port->lock, flags);
283 	count = kfifo_len(&port->write_fifo);
284 	spin_unlock_irqrestore(&port->lock, flags);
285 
286 	if (count > port->bulk_out_size)
287 		count = port->bulk_out_size;
288 
289 	if (count != 0) {
290 		allow = kmalloc(1, GFP_KERNEL);
291 		if (!allow) {
292 			dev_err_console(port, "%s(): kmalloc failed\n",
293 					__func__);
294 			return;
295 		}
296 		result = usb_control_msg(port->serial->dev,
297 				usb_rcvctrlpipe(port->serial->dev, 0),
298 				OTI6858_REQ_T_CHECK_TXBUFF,
299 				OTI6858_REQ_CHECK_TXBUFF,
300 				count, 0, allow, 1, 100);
301 		if (result != 1 || *allow != 0)
302 			count = 0;
303 		kfree(allow);
304 	}
305 
306 	if (count == 0) {
307 		priv->flags.write_urb_in_use = 0;
308 
309 		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
310 		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
311 		if (result != 0) {
312 			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
313 				__func__, result);
314 		}
315 		return;
316 	}
317 
318 	count = kfifo_out_locked(&port->write_fifo,
319 					port->write_urb->transfer_buffer,
320 					count, &port->lock);
321 	port->write_urb->transfer_buffer_length = count;
322 	result = usb_submit_urb(port->write_urb, GFP_NOIO);
323 	if (result != 0) {
324 		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
325 				__func__, result);
326 		priv->flags.write_urb_in_use = 0;
327 	}
328 
329 	usb_serial_port_softint(port);
330 }
331 
332 static int oti6858_port_probe(struct usb_serial_port *port)
333 {
334 	struct oti6858_private *priv;
335 
336 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
337 	if (!priv)
338 		return -ENOMEM;
339 
340 	spin_lock_init(&priv->lock);
341 	priv->port = port;
342 	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
343 	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
344 
345 	usb_set_serial_port_data(port, priv);
346 
347 	return 0;
348 }
349 
350 static int oti6858_port_remove(struct usb_serial_port *port)
351 {
352 	struct oti6858_private *priv;
353 
354 	priv = usb_get_serial_port_data(port);
355 	kfree(priv);
356 
357 	return 0;
358 }
359 
360 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
361 			const unsigned char *buf, int count)
362 {
363 	if (!count)
364 		return count;
365 
366 	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
367 
368 	return count;
369 }
370 
371 static int oti6858_write_room(struct tty_struct *tty)
372 {
373 	struct usb_serial_port *port = tty->driver_data;
374 	int room = 0;
375 	unsigned long flags;
376 
377 	spin_lock_irqsave(&port->lock, flags);
378 	room = kfifo_avail(&port->write_fifo);
379 	spin_unlock_irqrestore(&port->lock, flags);
380 
381 	return room;
382 }
383 
384 static int oti6858_chars_in_buffer(struct tty_struct *tty)
385 {
386 	struct usb_serial_port *port = tty->driver_data;
387 	int chars = 0;
388 	unsigned long flags;
389 
390 	spin_lock_irqsave(&port->lock, flags);
391 	chars = kfifo_len(&port->write_fifo);
392 	spin_unlock_irqrestore(&port->lock, flags);
393 
394 	return chars;
395 }
396 
397 static void oti6858_init_termios(struct tty_struct *tty)
398 {
399 	tty->termios = tty_std_termios;
400 	tty->termios.c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
401 	tty->termios.c_ispeed = 38400;
402 	tty->termios.c_ospeed = 38400;
403 }
404 
405 static void oti6858_set_termios(struct tty_struct *tty,
406 		struct usb_serial_port *port, struct ktermios *old_termios)
407 {
408 	struct oti6858_private *priv = usb_get_serial_port_data(port);
409 	unsigned long flags;
410 	unsigned int cflag;
411 	u8 frame_fmt, control;
412 	__le16 divisor;
413 	int br;
414 
415 	if (!tty)
416 		return;
417 
418 	cflag = tty->termios.c_cflag;
419 
420 	spin_lock_irqsave(&priv->lock, flags);
421 	divisor = priv->pending_setup.divisor;
422 	frame_fmt = priv->pending_setup.frame_fmt;
423 	control = priv->pending_setup.control;
424 	spin_unlock_irqrestore(&priv->lock, flags);
425 
426 	frame_fmt &= ~FMT_DATA_BITS_MASK;
427 	switch (cflag & CSIZE) {
428 	case CS5:
429 		frame_fmt |= FMT_DATA_BITS_5;
430 		break;
431 	case CS6:
432 		frame_fmt |= FMT_DATA_BITS_6;
433 		break;
434 	case CS7:
435 		frame_fmt |= FMT_DATA_BITS_7;
436 		break;
437 	default:
438 	case CS8:
439 		frame_fmt |= FMT_DATA_BITS_8;
440 		break;
441 	}
442 
443 	/* manufacturer claims that this device can work with baud rates
444 	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
445 	 * guarantee that any other baud rate will work (especially
446 	 * the higher ones)
447 	 */
448 	br = tty_get_baud_rate(tty);
449 	if (br == 0) {
450 		divisor = 0;
451 	} else {
452 		int real_br;
453 		int new_divisor;
454 		br = min(br, OTI6858_MAX_BAUD_RATE);
455 
456 		new_divisor = (96000000 + 8 * br) / (16 * br);
457 		real_br = 96000000 / (16 * new_divisor);
458 		divisor = cpu_to_le16(new_divisor);
459 		tty_encode_baud_rate(tty, real_br, real_br);
460 	}
461 
462 	frame_fmt &= ~FMT_STOP_BITS_MASK;
463 	if ((cflag & CSTOPB) != 0)
464 		frame_fmt |= FMT_STOP_BITS_2;
465 	else
466 		frame_fmt |= FMT_STOP_BITS_1;
467 
468 	frame_fmt &= ~FMT_PARITY_MASK;
469 	if ((cflag & PARENB) != 0) {
470 		if ((cflag & PARODD) != 0)
471 			frame_fmt |= FMT_PARITY_ODD;
472 		else
473 			frame_fmt |= FMT_PARITY_EVEN;
474 	} else {
475 		frame_fmt |= FMT_PARITY_NONE;
476 	}
477 
478 	control &= ~CONTROL_MASK;
479 	if ((cflag & CRTSCTS) != 0)
480 		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
481 
482 	/* change control lines if we are switching to or from B0 */
483 	/* FIXME:
484 	spin_lock_irqsave(&priv->lock, flags);
485 	control = priv->line_control;
486 	if ((cflag & CBAUD) == B0)
487 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
488 	else
489 		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
490 	if (control != priv->line_control) {
491 		control = priv->line_control;
492 		spin_unlock_irqrestore(&priv->lock, flags);
493 		set_control_lines(serial->dev, control);
494 	} else {
495 		spin_unlock_irqrestore(&priv->lock, flags);
496 	}
497 	*/
498 
499 	spin_lock_irqsave(&priv->lock, flags);
500 	if (divisor != priv->pending_setup.divisor
501 			|| control != priv->pending_setup.control
502 			|| frame_fmt != priv->pending_setup.frame_fmt) {
503 		priv->pending_setup.divisor = divisor;
504 		priv->pending_setup.control = control;
505 		priv->pending_setup.frame_fmt = frame_fmt;
506 	}
507 	spin_unlock_irqrestore(&priv->lock, flags);
508 }
509 
510 static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
511 {
512 	struct oti6858_private *priv = usb_get_serial_port_data(port);
513 	struct ktermios tmp_termios;
514 	struct usb_serial *serial = port->serial;
515 	struct oti6858_control_pkt *buf;
516 	unsigned long flags;
517 	int result;
518 
519 	usb_clear_halt(serial->dev, port->write_urb->pipe);
520 	usb_clear_halt(serial->dev, port->read_urb->pipe);
521 
522 	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
523 	if (buf == NULL) {
524 		dev_err(&port->dev, "%s(): out of memory!\n", __func__);
525 		return -ENOMEM;
526 	}
527 
528 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
529 				OTI6858_REQ_T_GET_STATUS,
530 				OTI6858_REQ_GET_STATUS,
531 				0, 0,
532 				buf, OTI6858_CTRL_PKT_SIZE,
533 				100);
534 	if (result != OTI6858_CTRL_PKT_SIZE) {
535 		/* assume default (after power-on reset) values */
536 		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
537 		buf->frame_fmt = 0x03;	/* 8N1 */
538 		buf->something = 0x43;
539 		buf->control = 0x4c;	/* DTR, RTS */
540 		buf->tx_status = 0x00;
541 		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
542 		buf->rx_bytes_avail = 0x00;
543 	}
544 
545 	spin_lock_irqsave(&priv->lock, flags);
546 	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
547 	priv->pending_setup.divisor = buf->divisor;
548 	priv->pending_setup.frame_fmt = buf->frame_fmt;
549 	priv->pending_setup.control = buf->control;
550 	spin_unlock_irqrestore(&priv->lock, flags);
551 	kfree(buf);
552 
553 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
554 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
555 	if (result != 0) {
556 		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
557 			__func__, result);
558 		oti6858_close(port);
559 		return result;
560 	}
561 
562 	/* setup termios */
563 	if (tty)
564 		oti6858_set_termios(tty, port, &tmp_termios);
565 	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
566 	return 0;
567 }
568 
569 static void oti6858_close(struct usb_serial_port *port)
570 {
571 	struct oti6858_private *priv = usb_get_serial_port_data(port);
572 	unsigned long flags;
573 
574 	spin_lock_irqsave(&port->lock, flags);
575 	/* clear out any remaining data in the buffer */
576 	kfifo_reset_out(&port->write_fifo);
577 	spin_unlock_irqrestore(&port->lock, flags);
578 
579 	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
580 
581 	/* cancel scheduled setup */
582 	cancel_delayed_work_sync(&priv->delayed_setup_work);
583 	cancel_delayed_work_sync(&priv->delayed_write_work);
584 
585 	/* shutdown our urbs */
586 	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
587 	usb_kill_urb(port->write_urb);
588 	usb_kill_urb(port->read_urb);
589 	usb_kill_urb(port->interrupt_in_urb);
590 }
591 
592 static int oti6858_tiocmset(struct tty_struct *tty,
593 				unsigned int set, unsigned int clear)
594 {
595 	struct usb_serial_port *port = tty->driver_data;
596 	struct oti6858_private *priv = usb_get_serial_port_data(port);
597 	unsigned long flags;
598 	u8 control;
599 
600 	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
601 		__func__, set, clear);
602 
603 	/* FIXME: check if this is correct (active high/low) */
604 	spin_lock_irqsave(&priv->lock, flags);
605 	control = priv->pending_setup.control;
606 	if ((set & TIOCM_RTS) != 0)
607 		control |= CONTROL_RTS_HIGH;
608 	if ((set & TIOCM_DTR) != 0)
609 		control |= CONTROL_DTR_HIGH;
610 	if ((clear & TIOCM_RTS) != 0)
611 		control &= ~CONTROL_RTS_HIGH;
612 	if ((clear & TIOCM_DTR) != 0)
613 		control &= ~CONTROL_DTR_HIGH;
614 
615 	if (control != priv->pending_setup.control)
616 		priv->pending_setup.control = control;
617 
618 	spin_unlock_irqrestore(&priv->lock, flags);
619 	return 0;
620 }
621 
622 static int oti6858_tiocmget(struct tty_struct *tty)
623 {
624 	struct usb_serial_port *port = tty->driver_data;
625 	struct oti6858_private *priv = usb_get_serial_port_data(port);
626 	unsigned long flags;
627 	unsigned pin_state;
628 	unsigned result = 0;
629 
630 	spin_lock_irqsave(&priv->lock, flags);
631 	pin_state = priv->status.pin_state & PIN_MASK;
632 	spin_unlock_irqrestore(&priv->lock, flags);
633 
634 	/* FIXME: check if this is correct (active high/low) */
635 	if ((pin_state & PIN_RTS) != 0)
636 		result |= TIOCM_RTS;
637 	if ((pin_state & PIN_CTS) != 0)
638 		result |= TIOCM_CTS;
639 	if ((pin_state & PIN_DSR) != 0)
640 		result |= TIOCM_DSR;
641 	if ((pin_state & PIN_DTR) != 0)
642 		result |= TIOCM_DTR;
643 	if ((pin_state & PIN_RI) != 0)
644 		result |= TIOCM_RI;
645 	if ((pin_state & PIN_DCD) != 0)
646 		result |= TIOCM_CD;
647 
648 	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
649 
650 	return result;
651 }
652 
653 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
654 {
655 	struct oti6858_private *priv = usb_get_serial_port_data(port);
656 	unsigned long flags;
657 	unsigned int prev, status;
658 	unsigned int changed;
659 
660 	spin_lock_irqsave(&priv->lock, flags);
661 	prev = priv->status.pin_state;
662 	spin_unlock_irqrestore(&priv->lock, flags);
663 
664 	while (1) {
665 		wait_event_interruptible(port->delta_msr_wait,
666 					port->serial->disconnected ||
667 					priv->status.pin_state != prev);
668 		if (signal_pending(current))
669 			return -ERESTARTSYS;
670 
671 		if (port->serial->disconnected)
672 			return -EIO;
673 
674 		spin_lock_irqsave(&priv->lock, flags);
675 		status = priv->status.pin_state & PIN_MASK;
676 		spin_unlock_irqrestore(&priv->lock, flags);
677 
678 		changed = prev ^ status;
679 		/* FIXME: check if this is correct (active high/low) */
680 		if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
681 		    ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
682 		    ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
683 		    ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
684 			return 0;
685 		prev = status;
686 	}
687 
688 	/* NOTREACHED */
689 	return 0;
690 }
691 
692 static int oti6858_ioctl(struct tty_struct *tty,
693 			unsigned int cmd, unsigned long arg)
694 {
695 	struct usb_serial_port *port = tty->driver_data;
696 
697 	dev_dbg(&port->dev, "%s(cmd = 0x%04x, arg = 0x%08lx)\n", __func__, cmd, arg);
698 
699 	switch (cmd) {
700 	case TIOCMIWAIT:
701 		dev_dbg(&port->dev, "%s(): TIOCMIWAIT\n", __func__);
702 		return wait_modem_info(port, arg);
703 	default:
704 		dev_dbg(&port->dev, "%s(): 0x%04x not supported\n", __func__, cmd);
705 		break;
706 	}
707 	return -ENOIOCTLCMD;
708 }
709 
710 static void oti6858_read_int_callback(struct urb *urb)
711 {
712 	struct usb_serial_port *port =  urb->context;
713 	struct oti6858_private *priv = usb_get_serial_port_data(port);
714 	int transient = 0, can_recv = 0, resubmit = 1;
715 	int status = urb->status;
716 
717 	switch (status) {
718 	case 0:
719 		/* success */
720 		break;
721 	case -ECONNRESET:
722 	case -ENOENT:
723 	case -ESHUTDOWN:
724 		/* this urb is terminated, clean up */
725 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
726 			__func__, status);
727 		return;
728 	default:
729 		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
730 			__func__, status);
731 		break;
732 	}
733 
734 	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
735 		struct oti6858_control_pkt *xs = urb->transfer_buffer;
736 		unsigned long flags;
737 
738 		spin_lock_irqsave(&priv->lock, flags);
739 
740 		if (!priv->transient) {
741 			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
742 				if (xs->rx_bytes_avail == 0) {
743 					priv->transient = 4;
744 					priv->setup_done = 0;
745 					resubmit = 0;
746 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
747 					schedule_delayed_work(&priv->delayed_setup_work, 0);
748 				}
749 			}
750 		} else {
751 			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
752 				priv->transient = 0;
753 			} else if (!priv->setup_done) {
754 				resubmit = 0;
755 			} else if (--priv->transient == 0) {
756 				if (xs->rx_bytes_avail == 0) {
757 					priv->transient = 4;
758 					priv->setup_done = 0;
759 					resubmit = 0;
760 					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
761 					schedule_delayed_work(&priv->delayed_setup_work, 0);
762 				}
763 			}
764 		}
765 
766 		if (!priv->transient) {
767 			if (xs->pin_state != priv->status.pin_state)
768 				wake_up_interruptible(&port->delta_msr_wait);
769 			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
770 		}
771 
772 		if (!priv->transient && xs->rx_bytes_avail != 0) {
773 			can_recv = xs->rx_bytes_avail;
774 			priv->flags.read_urb_in_use = 1;
775 		}
776 
777 		transient = priv->transient;
778 		spin_unlock_irqrestore(&priv->lock, flags);
779 	}
780 
781 	if (can_recv) {
782 		int result;
783 
784 		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
785 		if (result != 0) {
786 			priv->flags.read_urb_in_use = 0;
787 			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
788 					" error %d\n", __func__, result);
789 		} else {
790 			resubmit = 0;
791 		}
792 	} else if (!transient) {
793 		unsigned long flags;
794 		int count;
795 
796 		spin_lock_irqsave(&port->lock, flags);
797 		count = kfifo_len(&port->write_fifo);
798 		spin_unlock_irqrestore(&port->lock, flags);
799 
800 		spin_lock_irqsave(&priv->lock, flags);
801 		if (priv->flags.write_urb_in_use == 0 && count != 0) {
802 			schedule_delayed_work(&priv->delayed_write_work, 0);
803 			resubmit = 0;
804 		}
805 		spin_unlock_irqrestore(&priv->lock, flags);
806 	}
807 
808 	if (resubmit) {
809 		int result;
810 
811 /*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
812 		result = usb_submit_urb(urb, GFP_ATOMIC);
813 		if (result != 0) {
814 			dev_err(&urb->dev->dev,
815 					"%s(): usb_submit_urb() failed with"
816 					" error %d\n", __func__, result);
817 		}
818 	}
819 }
820 
821 static void oti6858_read_bulk_callback(struct urb *urb)
822 {
823 	struct usb_serial_port *port =  urb->context;
824 	struct oti6858_private *priv = usb_get_serial_port_data(port);
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 	if (urb->actual_length > 0) {
840 		tty_insert_flip_string(&port->port, data, urb->actual_length);
841 		tty_flip_buffer_push(&port->port);
842 	}
843 
844 	/* schedule the interrupt urb */
845 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
846 	if (result != 0 && result != -EPERM) {
847 		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
848 				" error %d\n", __func__, result);
849 	}
850 }
851 
852 static void oti6858_write_bulk_callback(struct urb *urb)
853 {
854 	struct usb_serial_port *port =  urb->context;
855 	struct oti6858_private *priv = usb_get_serial_port_data(port);
856 	int status = urb->status;
857 	int result;
858 
859 	switch (status) {
860 	case 0:
861 		/* success */
862 		break;
863 	case -ECONNRESET:
864 	case -ENOENT:
865 	case -ESHUTDOWN:
866 		/* this urb is terminated, clean up */
867 		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
868 		priv->flags.write_urb_in_use = 0;
869 		return;
870 	default:
871 		/* error in the urb, so we have to resubmit it */
872 		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
873 		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
874 
875 		port->write_urb->transfer_buffer_length = 1;
876 		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
877 		if (result) {
878 			dev_err_console(port, "%s(): usb_submit_urb() failed,"
879 					" error %d\n", __func__, result);
880 		} else {
881 			return;
882 		}
883 	}
884 
885 	priv->flags.write_urb_in_use = 0;
886 
887 	/* schedule the interrupt urb if we are still open */
888 	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
889 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
890 	if (result != 0) {
891 		dev_err(&port->dev, "%s(): failed submitting int urb,"
892 					" error %d\n", __func__, result);
893 	}
894 }
895 
896 module_usb_serial_driver(serial_drivers, id_table);
897 
898 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
899 MODULE_AUTHOR(OTI6858_AUTHOR);
900 MODULE_LICENSE("GPL");
901