1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
  4 *
  5 * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
  6 * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
  7 * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
  8 * Copyright (C) 2003 IBM Corp.
  9 *
 10 * Many thanks to the authors of pl2303 driver: all functions in this file
 11 * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
 12 *
 13 * Warning! You use this driver on your own risk! The only official
 14 * description of this device I have is datasheet from manufacturer,
 15 * and it doesn't contain almost any information needed to write a driver.
 16 * Almost all knowlegde used while writing this driver was gathered by:
 17 *  - analyzing traffic between device and the M$ Windows 2000 driver,
 18 *  - trying different bit combinations and checking pin states
 19 *    with a voltmeter,
 20 *  - receiving malformed frames and producing buffer overflows
 21 *    to learn how errors are reported,
 22 * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
 23 * CONNECTED TO IT!
 24 *
 25 * See Documentation/usb/usb-serial.rst for more information on using this
 26 * driver
 27 *
 28 * TODO:
 29 *  - implement correct flushing for ioctls and oti6858_close()
 30 *  - check how errors (rx overflow, parity error, framing error) are reported
 31 *  - implement oti6858_break_ctl()
 32 *  - implement more ioctls
 33 *  - test/implement flow control
 34 *  - allow setting custom baud rates
 35 */
 36
 37#include <linux/kernel.h>
 38#include <linux/errno.h>
 39#include <linux/slab.h>
 40#include <linux/tty.h>
 41#include <linux/tty_driver.h>
 42#include <linux/tty_flip.h>
 43#include <linux/serial.h>
 44#include <linux/module.h>
 45#include <linux/moduleparam.h>
 46#include <linux/spinlock.h>
 47#include <linux/usb.h>
 48#include <linux/usb/serial.h>
 49#include <linux/uaccess.h>
 50#include <linux/kfifo.h>
 51#include "oti6858.h"
 52
 53#define OTI6858_DESCRIPTION \
 54	"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
 55#define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
 56
 57static const struct usb_device_id id_table[] = {
 58	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
 59	{ }
 60};
 61
 62MODULE_DEVICE_TABLE(usb, id_table);
 63
 64/* requests */
 65#define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
 66#define	OTI6858_REQ_T_GET_STATUS	0x01
 67
 68#define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
 69#define	OTI6858_REQ_T_SET_LINE		0x00
 70
 71#define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
 72#define	OTI6858_REQ_T_CHECK_TXBUFF	0x00
 73
 74/* format of the control packet */
 75struct oti6858_control_pkt {
 76	__le16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
 77#define OTI6858_MAX_BAUD_RATE	3000000
 78	u8	frame_fmt;
 79#define FMT_STOP_BITS_MASK	0xc0
 80#define FMT_STOP_BITS_1		0x00
 81#define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
 82#define FMT_PARITY_MASK		0x38
 83#define FMT_PARITY_NONE		0x00
 84#define FMT_PARITY_ODD		0x08
 85#define FMT_PARITY_EVEN		0x18
 86#define FMT_PARITY_MARK		0x28
 87#define FMT_PARITY_SPACE	0x38
 88#define FMT_DATA_BITS_MASK	0x03
 89#define FMT_DATA_BITS_5		0x00
 90#define FMT_DATA_BITS_6		0x01
 91#define FMT_DATA_BITS_7		0x02
 92#define FMT_DATA_BITS_8		0x03
 93	u8	something;	/* always equals 0x43 */
 94	u8	control;	/* settings of flow control lines */
 95#define CONTROL_MASK		0x0c
 96#define CONTROL_DTR_HIGH	0x08
 97#define CONTROL_RTS_HIGH	0x04
 98	u8	tx_status;
 99#define	TX_BUFFER_EMPTIED	0x09
100	u8	pin_state;
101#define PIN_MASK		0x3f
102#define PIN_MSR_MASK		0x1b
103#define PIN_RTS			0x20	/* output pin */
104#define PIN_CTS			0x10	/* input pin, active low */
105#define PIN_DSR			0x08	/* input pin, active low */
106#define PIN_DTR			0x04	/* output pin */
107#define PIN_RI			0x02	/* input pin, active low */
108#define PIN_DCD			0x01	/* input pin, active low */
109	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
110};
111
112#define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
113#define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
114	(((a)->divisor == (priv)->pending_setup.divisor) \
115	  && ((a)->control == (priv)->pending_setup.control) \
116	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
117
118/* function prototypes */
119static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port);
120static void oti6858_close(struct usb_serial_port *port);
121static void oti6858_set_termios(struct tty_struct *tty,
122				struct usb_serial_port *port,
123				const struct ktermios *old_termios);
124static void oti6858_init_termios(struct tty_struct *tty);
125static void oti6858_read_int_callback(struct urb *urb);
126static void oti6858_read_bulk_callback(struct urb *urb);
127static void oti6858_write_bulk_callback(struct urb *urb);
128static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
129			const unsigned char *buf, int count);
130static unsigned int oti6858_write_room(struct tty_struct *tty);
131static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty);
132static int oti6858_tiocmget(struct tty_struct *tty);
133static int oti6858_tiocmset(struct tty_struct *tty,
134				unsigned int set, unsigned int clear);
135static int oti6858_port_probe(struct usb_serial_port *port);
136static void oti6858_port_remove(struct usb_serial_port *port);
137
138/* device info */
139static struct usb_serial_driver oti6858_device = {
140	.driver = {
141		.owner =	THIS_MODULE,
142		.name =		"oti6858",
143	},
144	.id_table =		id_table,
145	.num_ports =		1,
146	.num_bulk_in =		1,
147	.num_bulk_out =		1,
148	.num_interrupt_in =	1,
149	.open =			oti6858_open,
150	.close =		oti6858_close,
151	.write =		oti6858_write,
152	.set_termios =		oti6858_set_termios,
153	.init_termios = 	oti6858_init_termios,
154	.tiocmget =		oti6858_tiocmget,
155	.tiocmset =		oti6858_tiocmset,
156	.tiocmiwait =		usb_serial_generic_tiocmiwait,
157	.read_bulk_callback =	oti6858_read_bulk_callback,
158	.read_int_callback =	oti6858_read_int_callback,
159	.write_bulk_callback =	oti6858_write_bulk_callback,
160	.write_room =		oti6858_write_room,
161	.chars_in_buffer =	oti6858_chars_in_buffer,
162	.port_probe =		oti6858_port_probe,
163	.port_remove =		oti6858_port_remove,
164};
165
166static struct usb_serial_driver * const serial_drivers[] = {
167	&oti6858_device, NULL
168};
169
170struct oti6858_private {
171	spinlock_t lock;
172
173	struct oti6858_control_pkt status;
174
175	struct {
176		u8 read_urb_in_use;
177		u8 write_urb_in_use;
178	} flags;
179	struct delayed_work delayed_write_work;
180
181	struct {
182		__le16 divisor;
183		u8 frame_fmt;
184		u8 control;
185	} pending_setup;
186	u8 transient;
187	u8 setup_done;
188	struct delayed_work delayed_setup_work;
189
190	struct usb_serial_port *port;   /* USB port with which associated */
191};
192
193static void setup_line(struct work_struct *work)
194{
195	struct oti6858_private *priv = container_of(work,
196			struct oti6858_private, delayed_setup_work.work);
197	struct usb_serial_port *port = priv->port;
198	struct oti6858_control_pkt *new_setup;
199	unsigned long flags;
200	int result;
201
202	new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
203	if (!new_setup) {
204		/* we will try again */
205		schedule_delayed_work(&priv->delayed_setup_work,
206						msecs_to_jiffies(2));
207		return;
208	}
209
210	result = usb_control_msg(port->serial->dev,
211				usb_rcvctrlpipe(port->serial->dev, 0),
212				OTI6858_REQ_T_GET_STATUS,
213				OTI6858_REQ_GET_STATUS,
214				0, 0,
215				new_setup, OTI6858_CTRL_PKT_SIZE,
216				100);
217
218	if (result != OTI6858_CTRL_PKT_SIZE) {
219		dev_err(&port->dev, "%s(): error reading status\n", __func__);
220		kfree(new_setup);
221		/* we will try again */
222		schedule_delayed_work(&priv->delayed_setup_work,
223							msecs_to_jiffies(2));
224		return;
225	}
226
227	spin_lock_irqsave(&priv->lock, flags);
228	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
229		new_setup->divisor = priv->pending_setup.divisor;
230		new_setup->control = priv->pending_setup.control;
231		new_setup->frame_fmt = priv->pending_setup.frame_fmt;
232
233		spin_unlock_irqrestore(&priv->lock, flags);
234		result = usb_control_msg(port->serial->dev,
235					usb_sndctrlpipe(port->serial->dev, 0),
236					OTI6858_REQ_T_SET_LINE,
237					OTI6858_REQ_SET_LINE,
238					0, 0,
239					new_setup, OTI6858_CTRL_PKT_SIZE,
240					100);
241	} else {
242		spin_unlock_irqrestore(&priv->lock, flags);
243		result = 0;
244	}
245	kfree(new_setup);
246
247	spin_lock_irqsave(&priv->lock, flags);
248	if (result != OTI6858_CTRL_PKT_SIZE)
249		priv->transient = 0;
250	priv->setup_done = 1;
251	spin_unlock_irqrestore(&priv->lock, flags);
252
253	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
254	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
255	if (result != 0) {
256		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
257			__func__, result);
258	}
259}
260
261static void send_data(struct work_struct *work)
262{
263	struct oti6858_private *priv = container_of(work,
264			struct oti6858_private, delayed_write_work.work);
265	struct usb_serial_port *port = priv->port;
266	int count = 0, result;
267	unsigned long flags;
268	u8 *allow;
269
270	spin_lock_irqsave(&priv->lock, flags);
271	if (priv->flags.write_urb_in_use) {
272		spin_unlock_irqrestore(&priv->lock, flags);
273		schedule_delayed_work(&priv->delayed_write_work,
274						msecs_to_jiffies(2));
275		return;
276	}
277	priv->flags.write_urb_in_use = 1;
278	spin_unlock_irqrestore(&priv->lock, flags);
279
280	spin_lock_irqsave(&port->lock, flags);
281	count = kfifo_len(&port->write_fifo);
282	spin_unlock_irqrestore(&port->lock, flags);
283
284	if (count > port->bulk_out_size)
285		count = port->bulk_out_size;
286
287	if (count != 0) {
288		allow = kmalloc(1, GFP_KERNEL);
289		if (!allow)
290			return;
291
292		result = usb_control_msg(port->serial->dev,
293				usb_rcvctrlpipe(port->serial->dev, 0),
294				OTI6858_REQ_T_CHECK_TXBUFF,
295				OTI6858_REQ_CHECK_TXBUFF,
296				count, 0, allow, 1, 100);
297		if (result != 1 || *allow != 0)
298			count = 0;
299		kfree(allow);
300	}
301
302	if (count == 0) {
303		priv->flags.write_urb_in_use = 0;
304
305		dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
306		result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
307		if (result != 0) {
308			dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
309				__func__, result);
310		}
311		return;
312	}
313
314	count = kfifo_out_locked(&port->write_fifo,
315					port->write_urb->transfer_buffer,
316					count, &port->lock);
317	port->write_urb->transfer_buffer_length = count;
318	result = usb_submit_urb(port->write_urb, GFP_NOIO);
319	if (result != 0) {
320		dev_err_console(port, "%s(): usb_submit_urb() failed with error %d\n",
321				__func__, result);
322		priv->flags.write_urb_in_use = 0;
323	}
324
325	usb_serial_port_softint(port);
326}
327
328static int oti6858_port_probe(struct usb_serial_port *port)
329{
330	struct oti6858_private *priv;
331
332	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
333	if (!priv)
334		return -ENOMEM;
335
336	spin_lock_init(&priv->lock);
337	priv->port = port;
338	INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
339	INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
340
341	usb_set_serial_port_data(port, priv);
342
343	port->port.drain_delay = 256;	/* FIXME: check the FIFO length */
344
345	return 0;
346}
347
348static void oti6858_port_remove(struct usb_serial_port *port)
349{
350	struct oti6858_private *priv;
351
352	priv = usb_get_serial_port_data(port);
353	kfree(priv);
354}
355
356static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
357			const unsigned char *buf, int count)
358{
359	if (!count)
360		return count;
361
362	count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
363
364	return count;
365}
366
367static unsigned int oti6858_write_room(struct tty_struct *tty)
368{
369	struct usb_serial_port *port = tty->driver_data;
370	unsigned int room;
371	unsigned long flags;
372
373	spin_lock_irqsave(&port->lock, flags);
374	room = kfifo_avail(&port->write_fifo);
375	spin_unlock_irqrestore(&port->lock, flags);
376
377	return room;
378}
379
380static unsigned int oti6858_chars_in_buffer(struct tty_struct *tty)
381{
382	struct usb_serial_port *port = tty->driver_data;
383	unsigned int chars;
384	unsigned long flags;
385
386	spin_lock_irqsave(&port->lock, flags);
387	chars = kfifo_len(&port->write_fifo);
388	spin_unlock_irqrestore(&port->lock, flags);
389
390	return chars;
391}
392
393static void oti6858_init_termios(struct tty_struct *tty)
394{
395	tty_encode_baud_rate(tty, 38400, 38400);
396}
397
398static void oti6858_set_termios(struct tty_struct *tty,
399				struct usb_serial_port *port,
400				const struct ktermios *old_termios)
401{
402	struct oti6858_private *priv = usb_get_serial_port_data(port);
403	unsigned long flags;
404	unsigned int cflag;
405	u8 frame_fmt, control;
406	__le16 divisor;
407	int br;
408
409	cflag = tty->termios.c_cflag;
410
411	spin_lock_irqsave(&priv->lock, flags);
412	divisor = priv->pending_setup.divisor;
413	frame_fmt = priv->pending_setup.frame_fmt;
414	control = priv->pending_setup.control;
415	spin_unlock_irqrestore(&priv->lock, flags);
416
417	frame_fmt &= ~FMT_DATA_BITS_MASK;
418	switch (cflag & CSIZE) {
419	case CS5:
420		frame_fmt |= FMT_DATA_BITS_5;
421		break;
422	case CS6:
423		frame_fmt |= FMT_DATA_BITS_6;
424		break;
425	case CS7:
426		frame_fmt |= FMT_DATA_BITS_7;
427		break;
428	default:
429	case CS8:
430		frame_fmt |= FMT_DATA_BITS_8;
431		break;
432	}
433
434	/* manufacturer claims that this device can work with baud rates
435	 * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
436	 * guarantee that any other baud rate will work (especially
437	 * the higher ones)
438	 */
439	br = tty_get_baud_rate(tty);
440	if (br == 0) {
441		divisor = 0;
442	} else {
443		int real_br;
444		int new_divisor;
445		br = min(br, OTI6858_MAX_BAUD_RATE);
446
447		new_divisor = (96000000 + 8 * br) / (16 * br);
448		real_br = 96000000 / (16 * new_divisor);
449		divisor = cpu_to_le16(new_divisor);
450		tty_encode_baud_rate(tty, real_br, real_br);
451	}
452
453	frame_fmt &= ~FMT_STOP_BITS_MASK;
454	if ((cflag & CSTOPB) != 0)
455		frame_fmt |= FMT_STOP_BITS_2;
456	else
457		frame_fmt |= FMT_STOP_BITS_1;
458
459	frame_fmt &= ~FMT_PARITY_MASK;
460	if ((cflag & PARENB) != 0) {
461		if ((cflag & PARODD) != 0)
462			frame_fmt |= FMT_PARITY_ODD;
463		else
464			frame_fmt |= FMT_PARITY_EVEN;
465	} else {
466		frame_fmt |= FMT_PARITY_NONE;
467	}
468
469	control &= ~CONTROL_MASK;
470	if ((cflag & CRTSCTS) != 0)
471		control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
472
473	/* change control lines if we are switching to or from B0 */
474	/* FIXME:
475	spin_lock_irqsave(&priv->lock, flags);
476	control = priv->line_control;
477	if ((cflag & CBAUD) == B0)
478		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
479	else
480		priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
481	if (control != priv->line_control) {
482		control = priv->line_control;
483		spin_unlock_irqrestore(&priv->lock, flags);
484		set_control_lines(serial->dev, control);
485	} else {
486		spin_unlock_irqrestore(&priv->lock, flags);
487	}
488	*/
489
490	spin_lock_irqsave(&priv->lock, flags);
491	if (divisor != priv->pending_setup.divisor
492			|| control != priv->pending_setup.control
493			|| frame_fmt != priv->pending_setup.frame_fmt) {
494		priv->pending_setup.divisor = divisor;
495		priv->pending_setup.control = control;
496		priv->pending_setup.frame_fmt = frame_fmt;
497	}
498	spin_unlock_irqrestore(&priv->lock, flags);
499}
500
501static int oti6858_open(struct tty_struct *tty, struct usb_serial_port *port)
502{
503	struct oti6858_private *priv = usb_get_serial_port_data(port);
504	struct usb_serial *serial = port->serial;
505	struct oti6858_control_pkt *buf;
506	unsigned long flags;
507	int result;
508
509	usb_clear_halt(serial->dev, port->write_urb->pipe);
510	usb_clear_halt(serial->dev, port->read_urb->pipe);
511
512	buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
513	if (!buf)
514		return -ENOMEM;
515
516	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
517				OTI6858_REQ_T_GET_STATUS,
518				OTI6858_REQ_GET_STATUS,
519				0, 0,
520				buf, OTI6858_CTRL_PKT_SIZE,
521				100);
522	if (result != OTI6858_CTRL_PKT_SIZE) {
523		/* assume default (after power-on reset) values */
524		buf->divisor = cpu_to_le16(0x009c);	/* 38400 bps */
525		buf->frame_fmt = 0x03;	/* 8N1 */
526		buf->something = 0x43;
527		buf->control = 0x4c;	/* DTR, RTS */
528		buf->tx_status = 0x00;
529		buf->pin_state = 0x5b;	/* RTS, CTS, DSR, DTR, RI, DCD */
530		buf->rx_bytes_avail = 0x00;
531	}
532
533	spin_lock_irqsave(&priv->lock, flags);
534	memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
535	priv->pending_setup.divisor = buf->divisor;
536	priv->pending_setup.frame_fmt = buf->frame_fmt;
537	priv->pending_setup.control = buf->control;
538	spin_unlock_irqrestore(&priv->lock, flags);
539	kfree(buf);
540
541	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
542	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
543	if (result != 0) {
544		dev_err(&port->dev, "%s(): usb_submit_urb() failed with error %d\n",
545			__func__, result);
546		oti6858_close(port);
547		return result;
548	}
549
550	/* setup termios */
551	if (tty)
552		oti6858_set_termios(tty, port, NULL);
553
554	return 0;
555}
556
557static void oti6858_close(struct usb_serial_port *port)
558{
559	struct oti6858_private *priv = usb_get_serial_port_data(port);
560	unsigned long flags;
561
562	spin_lock_irqsave(&port->lock, flags);
563	/* clear out any remaining data in the buffer */
564	kfifo_reset_out(&port->write_fifo);
565	spin_unlock_irqrestore(&port->lock, flags);
566
567	dev_dbg(&port->dev, "%s(): after buf_clear()\n", __func__);
568
569	/* cancel scheduled setup */
570	cancel_delayed_work_sync(&priv->delayed_setup_work);
571	cancel_delayed_work_sync(&priv->delayed_write_work);
572
573	/* shutdown our urbs */
574	dev_dbg(&port->dev, "%s(): shutting down urbs\n", __func__);
575	usb_kill_urb(port->write_urb);
576	usb_kill_urb(port->read_urb);
577	usb_kill_urb(port->interrupt_in_urb);
578}
579
580static int oti6858_tiocmset(struct tty_struct *tty,
581				unsigned int set, unsigned int clear)
582{
583	struct usb_serial_port *port = tty->driver_data;
584	struct oti6858_private *priv = usb_get_serial_port_data(port);
585	unsigned long flags;
586	u8 control;
587
588	dev_dbg(&port->dev, "%s(set = 0x%08x, clear = 0x%08x)\n",
589		__func__, set, clear);
590
591	/* FIXME: check if this is correct (active high/low) */
592	spin_lock_irqsave(&priv->lock, flags);
593	control = priv->pending_setup.control;
594	if ((set & TIOCM_RTS) != 0)
595		control |= CONTROL_RTS_HIGH;
596	if ((set & TIOCM_DTR) != 0)
597		control |= CONTROL_DTR_HIGH;
598	if ((clear & TIOCM_RTS) != 0)
599		control &= ~CONTROL_RTS_HIGH;
600	if ((clear & TIOCM_DTR) != 0)
601		control &= ~CONTROL_DTR_HIGH;
602
603	if (control != priv->pending_setup.control)
604		priv->pending_setup.control = control;
605
606	spin_unlock_irqrestore(&priv->lock, flags);
607	return 0;
608}
609
610static int oti6858_tiocmget(struct tty_struct *tty)
611{
612	struct usb_serial_port *port = tty->driver_data;
613	struct oti6858_private *priv = usb_get_serial_port_data(port);
614	unsigned long flags;
615	unsigned pin_state;
616	unsigned result = 0;
617
618	spin_lock_irqsave(&priv->lock, flags);
619	pin_state = priv->status.pin_state & PIN_MASK;
620	spin_unlock_irqrestore(&priv->lock, flags);
621
622	/* FIXME: check if this is correct (active high/low) */
623	if ((pin_state & PIN_RTS) != 0)
624		result |= TIOCM_RTS;
625	if ((pin_state & PIN_CTS) != 0)
626		result |= TIOCM_CTS;
627	if ((pin_state & PIN_DSR) != 0)
628		result |= TIOCM_DSR;
629	if ((pin_state & PIN_DTR) != 0)
630		result |= TIOCM_DTR;
631	if ((pin_state & PIN_RI) != 0)
632		result |= TIOCM_RI;
633	if ((pin_state & PIN_DCD) != 0)
634		result |= TIOCM_CD;
635
636	dev_dbg(&port->dev, "%s() = 0x%08x\n", __func__, result);
637
638	return result;
639}
640
641static void oti6858_read_int_callback(struct urb *urb)
642{
643	struct usb_serial_port *port =  urb->context;
644	struct oti6858_private *priv = usb_get_serial_port_data(port);
645	int transient = 0, can_recv = 0, resubmit = 1;
646	int status = urb->status;
647
648	switch (status) {
649	case 0:
650		/* success */
651		break;
652	case -ECONNRESET:
653	case -ENOENT:
654	case -ESHUTDOWN:
655		/* this urb is terminated, clean up */
656		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n",
657			__func__, status);
658		return;
659	default:
660		dev_dbg(&urb->dev->dev, "%s(): nonzero urb status received: %d\n",
661			__func__, status);
662		break;
663	}
664
665	if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
666		struct oti6858_control_pkt *xs = urb->transfer_buffer;
667		unsigned long flags;
668
669		spin_lock_irqsave(&priv->lock, flags);
670
671		if (!priv->transient) {
672			if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
673				if (xs->rx_bytes_avail == 0) {
674					priv->transient = 4;
675					priv->setup_done = 0;
676					resubmit = 0;
677					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
678					schedule_delayed_work(&priv->delayed_setup_work, 0);
679				}
680			}
681		} else {
682			if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
683				priv->transient = 0;
684			} else if (!priv->setup_done) {
685				resubmit = 0;
686			} else if (--priv->transient == 0) {
687				if (xs->rx_bytes_avail == 0) {
688					priv->transient = 4;
689					priv->setup_done = 0;
690					resubmit = 0;
691					dev_dbg(&port->dev, "%s(): scheduling setup_line()\n", __func__);
692					schedule_delayed_work(&priv->delayed_setup_work, 0);
693				}
694			}
695		}
696
697		if (!priv->transient) {
698			u8 delta = xs->pin_state ^ priv->status.pin_state;
699
700			if (delta & PIN_MSR_MASK) {
701				if (delta & PIN_CTS)
702					port->icount.cts++;
703				if (delta & PIN_DSR)
704					port->icount.dsr++;
705				if (delta & PIN_RI)
706					port->icount.rng++;
707				if (delta & PIN_DCD)
708					port->icount.dcd++;
709
710				wake_up_interruptible(&port->port.delta_msr_wait);
711			}
712
713			memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
714		}
715
716		if (!priv->transient && xs->rx_bytes_avail != 0) {
717			can_recv = xs->rx_bytes_avail;
718			priv->flags.read_urb_in_use = 1;
719		}
720
721		transient = priv->transient;
722		spin_unlock_irqrestore(&priv->lock, flags);
723	}
724
725	if (can_recv) {
726		int result;
727
728		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
729		if (result != 0) {
730			priv->flags.read_urb_in_use = 0;
731			dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
732					" error %d\n", __func__, result);
733		} else {
734			resubmit = 0;
735		}
736	} else if (!transient) {
737		unsigned long flags;
738		int count;
739
740		spin_lock_irqsave(&port->lock, flags);
741		count = kfifo_len(&port->write_fifo);
742		spin_unlock_irqrestore(&port->lock, flags);
743
744		spin_lock_irqsave(&priv->lock, flags);
745		if (priv->flags.write_urb_in_use == 0 && count != 0) {
746			schedule_delayed_work(&priv->delayed_write_work, 0);
747			resubmit = 0;
748		}
749		spin_unlock_irqrestore(&priv->lock, flags);
750	}
751
752	if (resubmit) {
753		int result;
754
755/*		dev_dbg(&urb->dev->dev, "%s(): submitting interrupt urb\n", __func__); */
756		result = usb_submit_urb(urb, GFP_ATOMIC);
757		if (result != 0) {
758			dev_err(&urb->dev->dev,
759					"%s(): usb_submit_urb() failed with"
760					" error %d\n", __func__, result);
761		}
762	}
763}
764
765static void oti6858_read_bulk_callback(struct urb *urb)
766{
767	struct usb_serial_port *port =  urb->context;
768	struct oti6858_private *priv = usb_get_serial_port_data(port);
769	unsigned char *data = urb->transfer_buffer;
770	unsigned long flags;
771	int status = urb->status;
772	int result;
773
774	spin_lock_irqsave(&priv->lock, flags);
775	priv->flags.read_urb_in_use = 0;
776	spin_unlock_irqrestore(&priv->lock, flags);
777
778	if (status != 0) {
779		dev_dbg(&urb->dev->dev, "%s(): unable to handle the error, exiting\n", __func__);
780		return;
781	}
782
783	if (urb->actual_length > 0) {
784		tty_insert_flip_string(&port->port, data, urb->actual_length);
785		tty_flip_buffer_push(&port->port);
786	}
787
788	/* schedule the interrupt urb */
789	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
790	if (result != 0 && result != -EPERM) {
791		dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
792				" error %d\n", __func__, result);
793	}
794}
795
796static void oti6858_write_bulk_callback(struct urb *urb)
797{
798	struct usb_serial_port *port =  urb->context;
799	struct oti6858_private *priv = usb_get_serial_port_data(port);
800	int status = urb->status;
801	int result;
802
803	switch (status) {
804	case 0:
805		/* success */
806		break;
807	case -ECONNRESET:
808	case -ENOENT:
809	case -ESHUTDOWN:
810		/* this urb is terminated, clean up */
811		dev_dbg(&urb->dev->dev, "%s(): urb shutting down with status: %d\n", __func__, status);
812		priv->flags.write_urb_in_use = 0;
813		return;
814	default:
815		/* error in the urb, so we have to resubmit it */
816		dev_dbg(&urb->dev->dev, "%s(): nonzero write bulk status received: %d\n", __func__, status);
817		dev_dbg(&urb->dev->dev, "%s(): overflow in write\n", __func__);
818
819		port->write_urb->transfer_buffer_length = 1;
820		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
821		if (result) {
822			dev_err_console(port, "%s(): usb_submit_urb() failed,"
823					" error %d\n", __func__, result);
824		} else {
825			return;
826		}
827	}
828
829	priv->flags.write_urb_in_use = 0;
830
831	/* schedule the interrupt urb if we are still open */
832	dev_dbg(&port->dev, "%s(): submitting interrupt urb\n", __func__);
833	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
834	if (result != 0) {
835		dev_err(&port->dev, "%s(): failed submitting int urb,"
836					" error %d\n", __func__, result);
837	}
838}
839
840module_usb_serial_driver(serial_drivers, id_table);
841
842MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
843MODULE_AUTHOR(OTI6858_AUTHOR);
844MODULE_LICENSE("GPL v2");