1 /*
2 *  Digi AccelePort USB-4 and USB-2 Serial Converters
3 *
4 *  Copyright 2000 by Digi International
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  Shamelessly based on Brian Warner's keyspan_pda.c and Greg Kroah-Hartman's
12 *  usb-serial driver.
13 *
14 *  Peter Berger (pberger@brimson.com)
15 *  Al Borchers (borchers@steinerpoint.com)
16 */
17 
18 #include <linux/kernel.h>
19 #include <linux/errno.h>
20 #include <linux/slab.h>
21 #include <linux/tty.h>
22 #include <linux/tty_driver.h>
23 #include <linux/tty_flip.h>
24 #include <linux/module.h>
25 #include <linux/spinlock.h>
26 #include <linux/workqueue.h>
27 #include <linux/uaccess.h>
28 #include <linux/usb.h>
29 #include <linux/wait.h>
30 #include <linux/usb/serial.h>
31 
32 /* Defines */
33 
34 #define DRIVER_AUTHOR "Peter Berger <pberger@brimson.com>, Al Borchers <borchers@steinerpoint.com>"
35 #define DRIVER_DESC "Digi AccelePort USB-2/USB-4 Serial Converter driver"
36 
37 /* port output buffer length -- must be <= transfer buffer length - 2 */
38 /* so we can be sure to send the full buffer in one urb */
39 #define DIGI_OUT_BUF_SIZE		8
40 
41 /* port input buffer length -- must be >= transfer buffer length - 3 */
42 /* so we can be sure to hold at least one full buffer from one urb */
43 #define DIGI_IN_BUF_SIZE		64
44 
45 /* retry timeout while sleeping */
46 #define DIGI_RETRY_TIMEOUT		(HZ/10)
47 
48 /* timeout while waiting for tty output to drain in close */
49 /* this delay is used twice in close, so the total delay could */
50 /* be twice this value */
51 #define DIGI_CLOSE_TIMEOUT		(5*HZ)
52 
53 
54 /* AccelePort USB Defines */
55 
56 /* ids */
57 #define DIGI_VENDOR_ID			0x05c5
58 #define DIGI_2_ID			0x0002	/* USB-2 */
59 #define DIGI_4_ID			0x0004	/* USB-4 */
60 
61 /* commands
62  * "INB": can be used on the in-band endpoint
63  * "OOB": can be used on the out-of-band endpoint
64  */
65 #define DIGI_CMD_SET_BAUD_RATE			0	/* INB, OOB */
66 #define DIGI_CMD_SET_WORD_SIZE			1	/* INB, OOB */
67 #define DIGI_CMD_SET_PARITY			2	/* INB, OOB */
68 #define DIGI_CMD_SET_STOP_BITS			3	/* INB, OOB */
69 #define DIGI_CMD_SET_INPUT_FLOW_CONTROL		4	/* INB, OOB */
70 #define DIGI_CMD_SET_OUTPUT_FLOW_CONTROL	5	/* INB, OOB */
71 #define DIGI_CMD_SET_DTR_SIGNAL			6	/* INB, OOB */
72 #define DIGI_CMD_SET_RTS_SIGNAL			7	/* INB, OOB */
73 #define DIGI_CMD_READ_INPUT_SIGNALS		8	/*      OOB */
74 #define DIGI_CMD_IFLUSH_FIFO			9	/*      OOB */
75 #define DIGI_CMD_RECEIVE_ENABLE			10	/* INB, OOB */
76 #define DIGI_CMD_BREAK_CONTROL			11	/* INB, OOB */
77 #define DIGI_CMD_LOCAL_LOOPBACK			12	/* INB, OOB */
78 #define DIGI_CMD_TRANSMIT_IDLE			13	/* INB, OOB */
79 #define DIGI_CMD_READ_UART_REGISTER		14	/*      OOB */
80 #define DIGI_CMD_WRITE_UART_REGISTER		15	/* INB, OOB */
81 #define DIGI_CMD_AND_UART_REGISTER		16	/* INB, OOB */
82 #define DIGI_CMD_OR_UART_REGISTER		17	/* INB, OOB */
83 #define DIGI_CMD_SEND_DATA			18	/* INB      */
84 #define DIGI_CMD_RECEIVE_DATA			19	/* INB      */
85 #define DIGI_CMD_RECEIVE_DISABLE		20	/* INB      */
86 #define DIGI_CMD_GET_PORT_TYPE			21	/*      OOB */
87 
88 /* baud rates */
89 #define DIGI_BAUD_50				0
90 #define DIGI_BAUD_75				1
91 #define DIGI_BAUD_110				2
92 #define DIGI_BAUD_150				3
93 #define DIGI_BAUD_200				4
94 #define DIGI_BAUD_300				5
95 #define DIGI_BAUD_600				6
96 #define DIGI_BAUD_1200				7
97 #define DIGI_BAUD_1800				8
98 #define DIGI_BAUD_2400				9
99 #define DIGI_BAUD_4800				10
100 #define DIGI_BAUD_7200				11
101 #define DIGI_BAUD_9600				12
102 #define DIGI_BAUD_14400				13
103 #define DIGI_BAUD_19200				14
104 #define DIGI_BAUD_28800				15
105 #define DIGI_BAUD_38400				16
106 #define DIGI_BAUD_57600				17
107 #define DIGI_BAUD_76800				18
108 #define DIGI_BAUD_115200			19
109 #define DIGI_BAUD_153600			20
110 #define DIGI_BAUD_230400			21
111 #define DIGI_BAUD_460800			22
112 
113 /* arguments */
114 #define DIGI_WORD_SIZE_5			0
115 #define DIGI_WORD_SIZE_6			1
116 #define DIGI_WORD_SIZE_7			2
117 #define DIGI_WORD_SIZE_8			3
118 
119 #define DIGI_PARITY_NONE			0
120 #define DIGI_PARITY_ODD				1
121 #define DIGI_PARITY_EVEN			2
122 #define DIGI_PARITY_MARK			3
123 #define DIGI_PARITY_SPACE			4
124 
125 #define DIGI_STOP_BITS_1			0
126 #define DIGI_STOP_BITS_2			1
127 
128 #define DIGI_INPUT_FLOW_CONTROL_XON_XOFF	1
129 #define DIGI_INPUT_FLOW_CONTROL_RTS		2
130 #define DIGI_INPUT_FLOW_CONTROL_DTR		4
131 
132 #define DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF	1
133 #define DIGI_OUTPUT_FLOW_CONTROL_CTS		2
134 #define DIGI_OUTPUT_FLOW_CONTROL_DSR		4
135 
136 #define DIGI_DTR_INACTIVE			0
137 #define DIGI_DTR_ACTIVE				1
138 #define DIGI_DTR_INPUT_FLOW_CONTROL		2
139 
140 #define DIGI_RTS_INACTIVE			0
141 #define DIGI_RTS_ACTIVE				1
142 #define DIGI_RTS_INPUT_FLOW_CONTROL		2
143 #define DIGI_RTS_TOGGLE				3
144 
145 #define DIGI_FLUSH_TX				1
146 #define DIGI_FLUSH_RX				2
147 #define DIGI_RESUME_TX				4 /* clears xoff condition */
148 
149 #define DIGI_TRANSMIT_NOT_IDLE			0
150 #define DIGI_TRANSMIT_IDLE			1
151 
152 #define DIGI_DISABLE				0
153 #define DIGI_ENABLE				1
154 
155 #define DIGI_DEASSERT				0
156 #define DIGI_ASSERT				1
157 
158 /* in band status codes */
159 #define DIGI_OVERRUN_ERROR			4
160 #define DIGI_PARITY_ERROR			8
161 #define DIGI_FRAMING_ERROR			16
162 #define DIGI_BREAK_ERROR			32
163 
164 /* out of band status */
165 #define DIGI_NO_ERROR				0
166 #define DIGI_BAD_FIRST_PARAMETER		1
167 #define DIGI_BAD_SECOND_PARAMETER		2
168 #define DIGI_INVALID_LINE			3
169 #define DIGI_INVALID_OPCODE			4
170 
171 /* input signals */
172 #define DIGI_READ_INPUT_SIGNALS_SLOT		1
173 #define DIGI_READ_INPUT_SIGNALS_ERR		2
174 #define DIGI_READ_INPUT_SIGNALS_BUSY		4
175 #define DIGI_READ_INPUT_SIGNALS_PE		8
176 #define DIGI_READ_INPUT_SIGNALS_CTS		16
177 #define DIGI_READ_INPUT_SIGNALS_DSR		32
178 #define DIGI_READ_INPUT_SIGNALS_RI		64
179 #define DIGI_READ_INPUT_SIGNALS_DCD		128
180 
181 
182 /* Structures */
183 
184 struct digi_serial {
185 	spinlock_t ds_serial_lock;
186 	struct usb_serial_port *ds_oob_port;	/* out-of-band port */
187 	int ds_oob_port_num;			/* index of out-of-band port */
188 	int ds_device_started;
189 };
190 
191 struct digi_port {
192 	spinlock_t dp_port_lock;
193 	int dp_port_num;
194 	int dp_out_buf_len;
195 	unsigned char dp_out_buf[DIGI_OUT_BUF_SIZE];
196 	int dp_write_urb_in_use;
197 	unsigned int dp_modem_signals;
198 	int dp_transmit_idle;
199 	wait_queue_head_t dp_transmit_idle_wait;
200 	int dp_throttled;
201 	int dp_throttle_restart;
202 	wait_queue_head_t dp_flush_wait;
203 	wait_queue_head_t dp_close_wait;	/* wait queue for close */
204 	struct work_struct dp_wakeup_work;
205 	struct usb_serial_port *dp_port;
206 };
207 
208 
209 /* Local Function Declarations */
210 
211 static void digi_wakeup_write_lock(struct work_struct *work);
212 static int digi_write_oob_command(struct usb_serial_port *port,
213 	unsigned char *buf, int count, int interruptible);
214 static int digi_write_inb_command(struct usb_serial_port *port,
215 	unsigned char *buf, int count, unsigned long timeout);
216 static int digi_set_modem_signals(struct usb_serial_port *port,
217 	unsigned int modem_signals, int interruptible);
218 static int digi_transmit_idle(struct usb_serial_port *port,
219 	unsigned long timeout);
220 static void digi_rx_throttle(struct tty_struct *tty);
221 static void digi_rx_unthrottle(struct tty_struct *tty);
222 static void digi_set_termios(struct tty_struct *tty,
223 		struct usb_serial_port *port, struct ktermios *old_termios);
224 static void digi_break_ctl(struct tty_struct *tty, int break_state);
225 static int digi_tiocmget(struct tty_struct *tty);
226 static int digi_tiocmset(struct tty_struct *tty, unsigned int set,
227 		unsigned int clear);
228 static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
229 		const unsigned char *buf, int count);
230 static void digi_write_bulk_callback(struct urb *urb);
231 static int digi_write_room(struct tty_struct *tty);
232 static int digi_chars_in_buffer(struct tty_struct *tty);
233 static int digi_open(struct tty_struct *tty, struct usb_serial_port *port);
234 static void digi_close(struct usb_serial_port *port);
235 static void digi_dtr_rts(struct usb_serial_port *port, int on);
236 static int digi_startup_device(struct usb_serial *serial);
237 static int digi_startup(struct usb_serial *serial);
238 static void digi_disconnect(struct usb_serial *serial);
239 static void digi_release(struct usb_serial *serial);
240 static int digi_port_probe(struct usb_serial_port *port);
241 static int digi_port_remove(struct usb_serial_port *port);
242 static void digi_read_bulk_callback(struct urb *urb);
243 static int digi_read_inb_callback(struct urb *urb);
244 static int digi_read_oob_callback(struct urb *urb);
245 
246 
247 static const struct usb_device_id id_table_combined[] = {
248 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
249 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
250 	{ }						/* Terminating entry */
251 };
252 
253 static const struct usb_device_id id_table_2[] = {
254 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
255 	{ }						/* Terminating entry */
256 };
257 
258 static const struct usb_device_id id_table_4[] = {
259 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
260 	{ }						/* Terminating entry */
261 };
262 
263 MODULE_DEVICE_TABLE(usb, id_table_combined);
264 
265 /* device info needed for the Digi serial converter */
266 
267 static struct usb_serial_driver digi_acceleport_2_device = {
268 	.driver = {
269 		.owner =		THIS_MODULE,
270 		.name =			"digi_2",
271 	},
272 	.description =			"Digi 2 port USB adapter",
273 	.id_table =			id_table_2,
274 	.num_ports =			3,
275 	.open =				digi_open,
276 	.close =			digi_close,
277 	.dtr_rts =			digi_dtr_rts,
278 	.write =			digi_write,
279 	.write_room =			digi_write_room,
280 	.write_bulk_callback = 		digi_write_bulk_callback,
281 	.read_bulk_callback =		digi_read_bulk_callback,
282 	.chars_in_buffer =		digi_chars_in_buffer,
283 	.throttle =			digi_rx_throttle,
284 	.unthrottle =			digi_rx_unthrottle,
285 	.set_termios =			digi_set_termios,
286 	.break_ctl =			digi_break_ctl,
287 	.tiocmget =			digi_tiocmget,
288 	.tiocmset =			digi_tiocmset,
289 	.attach =			digi_startup,
290 	.disconnect =			digi_disconnect,
291 	.release =			digi_release,
292 	.port_probe =			digi_port_probe,
293 	.port_remove =			digi_port_remove,
294 };
295 
296 static struct usb_serial_driver digi_acceleport_4_device = {
297 	.driver = {
298 		.owner =		THIS_MODULE,
299 		.name =			"digi_4",
300 	},
301 	.description =			"Digi 4 port USB adapter",
302 	.id_table =			id_table_4,
303 	.num_ports =			4,
304 	.open =				digi_open,
305 	.close =			digi_close,
306 	.write =			digi_write,
307 	.write_room =			digi_write_room,
308 	.write_bulk_callback = 		digi_write_bulk_callback,
309 	.read_bulk_callback =		digi_read_bulk_callback,
310 	.chars_in_buffer =		digi_chars_in_buffer,
311 	.throttle =			digi_rx_throttle,
312 	.unthrottle =			digi_rx_unthrottle,
313 	.set_termios =			digi_set_termios,
314 	.break_ctl =			digi_break_ctl,
315 	.tiocmget =			digi_tiocmget,
316 	.tiocmset =			digi_tiocmset,
317 	.attach =			digi_startup,
318 	.disconnect =			digi_disconnect,
319 	.release =			digi_release,
320 	.port_probe =			digi_port_probe,
321 	.port_remove =			digi_port_remove,
322 };
323 
324 static struct usb_serial_driver * const serial_drivers[] = {
325 	&digi_acceleport_2_device, &digi_acceleport_4_device, NULL
326 };
327 
328 /* Functions */
329 
330 /*
331  *  Cond Wait Interruptible Timeout Irqrestore
332  *
333  *  Do spin_unlock_irqrestore and interruptible_sleep_on_timeout
334  *  so that wake ups are not lost if they occur between the unlock
335  *  and the sleep.  In other words, spin_unlock_irqrestore and
336  *  interruptible_sleep_on_timeout are "atomic" with respect to
337  *  wake ups.  This is used to implement condition variables.
338  *
339  *  interruptible_sleep_on_timeout is deprecated and has been replaced
340  *  with the equivalent code.
341  */
342 
343 static long cond_wait_interruptible_timeout_irqrestore(
344 	wait_queue_head_t *q, long timeout,
345 	spinlock_t *lock, unsigned long flags)
346 __releases(lock)
347 {
348 	DEFINE_WAIT(wait);
349 
350 	prepare_to_wait(q, &wait, TASK_INTERRUPTIBLE);
351 	spin_unlock_irqrestore(lock, flags);
352 	timeout = schedule_timeout(timeout);
353 	finish_wait(q, &wait);
354 
355 	return timeout;
356 }
357 
358 
359 /*
360  *  Digi Wakeup Write
361  *
362  *  Wake up port, line discipline, and tty processes sleeping
363  *  on writes.
364  */
365 
366 static void digi_wakeup_write_lock(struct work_struct *work)
367 {
368 	struct digi_port *priv =
369 			container_of(work, struct digi_port, dp_wakeup_work);
370 	struct usb_serial_port *port = priv->dp_port;
371 	unsigned long flags;
372 
373 	spin_lock_irqsave(&priv->dp_port_lock, flags);
374 	tty_port_tty_wakeup(&port->port);
375 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
376 }
377 
378 /*
379  *  Digi Write OOB Command
380  *
381  *  Write commands on the out of band port.  Commands are 4
382  *  bytes each, multiple commands can be sent at once, and
383  *  no command will be split across USB packets.  Returns 0
384  *  if successful, -EINTR if interrupted while sleeping and
385  *  the interruptible flag is true, or a negative error
386  *  returned by usb_submit_urb.
387  */
388 
389 static int digi_write_oob_command(struct usb_serial_port *port,
390 	unsigned char *buf, int count, int interruptible)
391 {
392 	int ret = 0;
393 	int len;
394 	struct usb_serial_port *oob_port = (struct usb_serial_port *)((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
395 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
396 	unsigned long flags = 0;
397 
398 	dev_dbg(&port->dev,
399 		"digi_write_oob_command: TOP: port=%d, count=%d\n",
400 		oob_priv->dp_port_num, count);
401 
402 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
403 	while (count > 0) {
404 		while (oob_priv->dp_write_urb_in_use) {
405 			cond_wait_interruptible_timeout_irqrestore(
406 				&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
407 				&oob_priv->dp_port_lock, flags);
408 			if (interruptible && signal_pending(current))
409 				return -EINTR;
410 			spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
411 		}
412 
413 		/* len must be a multiple of 4, so commands are not split */
414 		len = min(count, oob_port->bulk_out_size);
415 		if (len > 4)
416 			len &= ~3;
417 		memcpy(oob_port->write_urb->transfer_buffer, buf, len);
418 		oob_port->write_urb->transfer_buffer_length = len;
419 		ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
420 		if (ret == 0) {
421 			oob_priv->dp_write_urb_in_use = 1;
422 			count -= len;
423 			buf += len;
424 		}
425 	}
426 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
427 	if (ret)
428 		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
429 			__func__, ret);
430 	return ret;
431 
432 }
433 
434 
435 /*
436  *  Digi Write In Band Command
437  *
438  *  Write commands on the given port.  Commands are 4
439  *  bytes each, multiple commands can be sent at once, and
440  *  no command will be split across USB packets.  If timeout
441  *  is non-zero, write in band command will return after
442  *  waiting unsuccessfully for the URB status to clear for
443  *  timeout ticks.  Returns 0 if successful, or a negative
444  *  error returned by digi_write.
445  */
446 
447 static int digi_write_inb_command(struct usb_serial_port *port,
448 	unsigned char *buf, int count, unsigned long timeout)
449 {
450 	int ret = 0;
451 	int len;
452 	struct digi_port *priv = usb_get_serial_port_data(port);
453 	unsigned char *data = port->write_urb->transfer_buffer;
454 	unsigned long flags = 0;
455 
456 	dev_dbg(&port->dev, "digi_write_inb_command: TOP: port=%d, count=%d\n",
457 		priv->dp_port_num, count);
458 
459 	if (timeout)
460 		timeout += jiffies;
461 	else
462 		timeout = ULONG_MAX;
463 
464 	spin_lock_irqsave(&priv->dp_port_lock, flags);
465 	while (count > 0 && ret == 0) {
466 		while (priv->dp_write_urb_in_use &&
467 		       time_before(jiffies, timeout)) {
468 			cond_wait_interruptible_timeout_irqrestore(
469 				&port->write_wait, DIGI_RETRY_TIMEOUT,
470 				&priv->dp_port_lock, flags);
471 			if (signal_pending(current))
472 				return -EINTR;
473 			spin_lock_irqsave(&priv->dp_port_lock, flags);
474 		}
475 
476 		/* len must be a multiple of 4 and small enough to */
477 		/* guarantee the write will send buffered data first, */
478 		/* so commands are in order with data and not split */
479 		len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
480 		if (len > 4)
481 			len &= ~3;
482 
483 		/* write any buffered data first */
484 		if (priv->dp_out_buf_len > 0) {
485 			data[0] = DIGI_CMD_SEND_DATA;
486 			data[1] = priv->dp_out_buf_len;
487 			memcpy(data + 2, priv->dp_out_buf,
488 				priv->dp_out_buf_len);
489 			memcpy(data + 2 + priv->dp_out_buf_len, buf, len);
490 			port->write_urb->transfer_buffer_length
491 				= priv->dp_out_buf_len + 2 + len;
492 		} else {
493 			memcpy(data, buf, len);
494 			port->write_urb->transfer_buffer_length = len;
495 		}
496 
497 		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
498 		if (ret == 0) {
499 			priv->dp_write_urb_in_use = 1;
500 			priv->dp_out_buf_len = 0;
501 			count -= len;
502 			buf += len;
503 		}
504 
505 	}
506 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
507 
508 	if (ret)
509 		dev_err(&port->dev,
510 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
511 			__func__, ret, priv->dp_port_num);
512 	return ret;
513 }
514 
515 
516 /*
517  *  Digi Set Modem Signals
518  *
519  *  Sets or clears DTR and RTS on the port, according to the
520  *  modem_signals argument.  Use TIOCM_DTR and TIOCM_RTS flags
521  *  for the modem_signals argument.  Returns 0 if successful,
522  *  -EINTR if interrupted while sleeping, or a non-zero error
523  *  returned by usb_submit_urb.
524  */
525 
526 static int digi_set_modem_signals(struct usb_serial_port *port,
527 	unsigned int modem_signals, int interruptible)
528 {
529 
530 	int ret;
531 	struct digi_port *port_priv = usb_get_serial_port_data(port);
532 	struct usb_serial_port *oob_port = (struct usb_serial_port *) ((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
533 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
534 	unsigned char *data = oob_port->write_urb->transfer_buffer;
535 	unsigned long flags = 0;
536 
537 
538 	dev_dbg(&port->dev,
539 		"digi_set_modem_signals: TOP: port=%d, modem_signals=0x%x\n",
540 		port_priv->dp_port_num, modem_signals);
541 
542 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
543 	spin_lock(&port_priv->dp_port_lock);
544 
545 	while (oob_priv->dp_write_urb_in_use) {
546 		spin_unlock(&port_priv->dp_port_lock);
547 		cond_wait_interruptible_timeout_irqrestore(
548 			&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
549 			&oob_priv->dp_port_lock, flags);
550 		if (interruptible && signal_pending(current))
551 			return -EINTR;
552 		spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
553 		spin_lock(&port_priv->dp_port_lock);
554 	}
555 	data[0] = DIGI_CMD_SET_DTR_SIGNAL;
556 	data[1] = port_priv->dp_port_num;
557 	data[2] = (modem_signals & TIOCM_DTR) ?
558 					DIGI_DTR_ACTIVE : DIGI_DTR_INACTIVE;
559 	data[3] = 0;
560 	data[4] = DIGI_CMD_SET_RTS_SIGNAL;
561 	data[5] = port_priv->dp_port_num;
562 	data[6] = (modem_signals & TIOCM_RTS) ?
563 					DIGI_RTS_ACTIVE : DIGI_RTS_INACTIVE;
564 	data[7] = 0;
565 
566 	oob_port->write_urb->transfer_buffer_length = 8;
567 
568 	ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
569 	if (ret == 0) {
570 		oob_priv->dp_write_urb_in_use = 1;
571 		port_priv->dp_modem_signals =
572 			(port_priv->dp_modem_signals&~(TIOCM_DTR|TIOCM_RTS))
573 			| (modem_signals&(TIOCM_DTR|TIOCM_RTS));
574 	}
575 	spin_unlock(&port_priv->dp_port_lock);
576 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
577 	if (ret)
578 		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
579 			__func__, ret);
580 	return ret;
581 }
582 
583 /*
584  *  Digi Transmit Idle
585  *
586  *  Digi transmit idle waits, up to timeout ticks, for the transmitter
587  *  to go idle.  It returns 0 if successful or a negative error.
588  *
589  *  There are race conditions here if more than one process is calling
590  *  digi_transmit_idle on the same port at the same time.  However, this
591  *  is only called from close, and only one process can be in close on a
592  *  port at a time, so its ok.
593  */
594 
595 static int digi_transmit_idle(struct usb_serial_port *port,
596 	unsigned long timeout)
597 {
598 	int ret;
599 	unsigned char buf[2];
600 	struct digi_port *priv = usb_get_serial_port_data(port);
601 	unsigned long flags = 0;
602 
603 	spin_lock_irqsave(&priv->dp_port_lock, flags);
604 	priv->dp_transmit_idle = 0;
605 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
606 
607 	buf[0] = DIGI_CMD_TRANSMIT_IDLE;
608 	buf[1] = 0;
609 
610 	timeout += jiffies;
611 
612 	ret = digi_write_inb_command(port, buf, 2, timeout - jiffies);
613 	if (ret != 0)
614 		return ret;
615 
616 	spin_lock_irqsave(&priv->dp_port_lock, flags);
617 
618 	while (time_before(jiffies, timeout) && !priv->dp_transmit_idle) {
619 		cond_wait_interruptible_timeout_irqrestore(
620 			&priv->dp_transmit_idle_wait, DIGI_RETRY_TIMEOUT,
621 			&priv->dp_port_lock, flags);
622 		if (signal_pending(current))
623 			return -EINTR;
624 		spin_lock_irqsave(&priv->dp_port_lock, flags);
625 	}
626 	priv->dp_transmit_idle = 0;
627 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
628 	return 0;
629 
630 }
631 
632 
633 static void digi_rx_throttle(struct tty_struct *tty)
634 {
635 	unsigned long flags;
636 	struct usb_serial_port *port = tty->driver_data;
637 	struct digi_port *priv = usb_get_serial_port_data(port);
638 
639 	/* stop receiving characters by not resubmitting the read urb */
640 	spin_lock_irqsave(&priv->dp_port_lock, flags);
641 	priv->dp_throttled = 1;
642 	priv->dp_throttle_restart = 0;
643 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
644 }
645 
646 
647 static void digi_rx_unthrottle(struct tty_struct *tty)
648 {
649 	int ret = 0;
650 	unsigned long flags;
651 	struct usb_serial_port *port = tty->driver_data;
652 	struct digi_port *priv = usb_get_serial_port_data(port);
653 
654 	spin_lock_irqsave(&priv->dp_port_lock, flags);
655 
656 	/* restart read chain */
657 	if (priv->dp_throttle_restart)
658 		ret = usb_submit_urb(port->read_urb, GFP_ATOMIC);
659 
660 	/* turn throttle off */
661 	priv->dp_throttled = 0;
662 	priv->dp_throttle_restart = 0;
663 
664 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
665 
666 	if (ret)
667 		dev_err(&port->dev,
668 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
669 			__func__, ret, priv->dp_port_num);
670 }
671 
672 
673 static void digi_set_termios(struct tty_struct *tty,
674 		struct usb_serial_port *port, struct ktermios *old_termios)
675 {
676 	struct digi_port *priv = usb_get_serial_port_data(port);
677 	struct device *dev = &port->dev;
678 	unsigned int iflag = tty->termios.c_iflag;
679 	unsigned int cflag = tty->termios.c_cflag;
680 	unsigned int old_iflag = old_termios->c_iflag;
681 	unsigned int old_cflag = old_termios->c_cflag;
682 	unsigned char buf[32];
683 	unsigned int modem_signals;
684 	int arg, ret;
685 	int i = 0;
686 	speed_t baud;
687 
688 	dev_dbg(dev,
689 		"digi_set_termios: TOP: port=%d, iflag=0x%x, old_iflag=0x%x, cflag=0x%x, old_cflag=0x%x\n",
690 		priv->dp_port_num, iflag, old_iflag, cflag, old_cflag);
691 
692 	/* set baud rate */
693 	baud = tty_get_baud_rate(tty);
694 	if (baud != tty_termios_baud_rate(old_termios)) {
695 		arg = -1;
696 
697 		/* reassert DTR and (maybe) RTS on transition from B0 */
698 		if ((old_cflag & CBAUD) == B0) {
699 			/* don't set RTS if using hardware flow control */
700 			/* and throttling input */
701 			modem_signals = TIOCM_DTR;
702 			if (!C_CRTSCTS(tty) || !tty_throttled(tty))
703 				modem_signals |= TIOCM_RTS;
704 			digi_set_modem_signals(port, modem_signals, 1);
705 		}
706 		switch (baud) {
707 		/* drop DTR and RTS on transition to B0 */
708 		case 0: digi_set_modem_signals(port, 0, 1); break;
709 		case 50: arg = DIGI_BAUD_50; break;
710 		case 75: arg = DIGI_BAUD_75; break;
711 		case 110: arg = DIGI_BAUD_110; break;
712 		case 150: arg = DIGI_BAUD_150; break;
713 		case 200: arg = DIGI_BAUD_200; break;
714 		case 300: arg = DIGI_BAUD_300; break;
715 		case 600: arg = DIGI_BAUD_600; break;
716 		case 1200: arg = DIGI_BAUD_1200; break;
717 		case 1800: arg = DIGI_BAUD_1800; break;
718 		case 2400: arg = DIGI_BAUD_2400; break;
719 		case 4800: arg = DIGI_BAUD_4800; break;
720 		case 9600: arg = DIGI_BAUD_9600; break;
721 		case 19200: arg = DIGI_BAUD_19200; break;
722 		case 38400: arg = DIGI_BAUD_38400; break;
723 		case 57600: arg = DIGI_BAUD_57600; break;
724 		case 115200: arg = DIGI_BAUD_115200; break;
725 		case 230400: arg = DIGI_BAUD_230400; break;
726 		case 460800: arg = DIGI_BAUD_460800; break;
727 		default:
728 			arg = DIGI_BAUD_9600;
729 			baud = 9600;
730 			break;
731 		}
732 		if (arg != -1) {
733 			buf[i++] = DIGI_CMD_SET_BAUD_RATE;
734 			buf[i++] = priv->dp_port_num;
735 			buf[i++] = arg;
736 			buf[i++] = 0;
737 		}
738 	}
739 	/* set parity */
740 	tty->termios.c_cflag &= ~CMSPAR;
741 
742 	if ((cflag&(PARENB|PARODD)) != (old_cflag&(PARENB|PARODD))) {
743 		if (cflag&PARENB) {
744 			if (cflag&PARODD)
745 				arg = DIGI_PARITY_ODD;
746 			else
747 				arg = DIGI_PARITY_EVEN;
748 		} else {
749 			arg = DIGI_PARITY_NONE;
750 		}
751 		buf[i++] = DIGI_CMD_SET_PARITY;
752 		buf[i++] = priv->dp_port_num;
753 		buf[i++] = arg;
754 		buf[i++] = 0;
755 	}
756 	/* set word size */
757 	if ((cflag&CSIZE) != (old_cflag&CSIZE)) {
758 		arg = -1;
759 		switch (cflag&CSIZE) {
760 		case CS5: arg = DIGI_WORD_SIZE_5; break;
761 		case CS6: arg = DIGI_WORD_SIZE_6; break;
762 		case CS7: arg = DIGI_WORD_SIZE_7; break;
763 		case CS8: arg = DIGI_WORD_SIZE_8; break;
764 		default:
765 			dev_dbg(dev,
766 				"digi_set_termios: can't handle word size %d\n",
767 				(cflag&CSIZE));
768 			break;
769 		}
770 
771 		if (arg != -1) {
772 			buf[i++] = DIGI_CMD_SET_WORD_SIZE;
773 			buf[i++] = priv->dp_port_num;
774 			buf[i++] = arg;
775 			buf[i++] = 0;
776 		}
777 
778 	}
779 
780 	/* set stop bits */
781 	if ((cflag&CSTOPB) != (old_cflag&CSTOPB)) {
782 
783 		if ((cflag&CSTOPB))
784 			arg = DIGI_STOP_BITS_2;
785 		else
786 			arg = DIGI_STOP_BITS_1;
787 
788 		buf[i++] = DIGI_CMD_SET_STOP_BITS;
789 		buf[i++] = priv->dp_port_num;
790 		buf[i++] = arg;
791 		buf[i++] = 0;
792 
793 	}
794 
795 	/* set input flow control */
796 	if ((iflag&IXOFF) != (old_iflag&IXOFF)
797 	    || (cflag&CRTSCTS) != (old_cflag&CRTSCTS)) {
798 		arg = 0;
799 		if (iflag&IXOFF)
800 			arg |= DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
801 		else
802 			arg &= ~DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
803 
804 		if (cflag&CRTSCTS) {
805 			arg |= DIGI_INPUT_FLOW_CONTROL_RTS;
806 
807 			/* On USB-4 it is necessary to assert RTS prior */
808 			/* to selecting RTS input flow control.  */
809 			buf[i++] = DIGI_CMD_SET_RTS_SIGNAL;
810 			buf[i++] = priv->dp_port_num;
811 			buf[i++] = DIGI_RTS_ACTIVE;
812 			buf[i++] = 0;
813 
814 		} else {
815 			arg &= ~DIGI_INPUT_FLOW_CONTROL_RTS;
816 		}
817 		buf[i++] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
818 		buf[i++] = priv->dp_port_num;
819 		buf[i++] = arg;
820 		buf[i++] = 0;
821 	}
822 
823 	/* set output flow control */
824 	if ((iflag & IXON) != (old_iflag & IXON)
825 	    || (cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
826 		arg = 0;
827 		if (iflag & IXON)
828 			arg |= DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
829 		else
830 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
831 
832 		if (cflag & CRTSCTS) {
833 			arg |= DIGI_OUTPUT_FLOW_CONTROL_CTS;
834 		} else {
835 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_CTS;
836 		}
837 
838 		buf[i++] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
839 		buf[i++] = priv->dp_port_num;
840 		buf[i++] = arg;
841 		buf[i++] = 0;
842 	}
843 
844 	/* set receive enable/disable */
845 	if ((cflag & CREAD) != (old_cflag & CREAD)) {
846 		if (cflag & CREAD)
847 			arg = DIGI_ENABLE;
848 		else
849 			arg = DIGI_DISABLE;
850 
851 		buf[i++] = DIGI_CMD_RECEIVE_ENABLE;
852 		buf[i++] = priv->dp_port_num;
853 		buf[i++] = arg;
854 		buf[i++] = 0;
855 	}
856 	ret = digi_write_oob_command(port, buf, i, 1);
857 	if (ret != 0)
858 		dev_dbg(dev, "digi_set_termios: write oob failed, ret=%d\n", ret);
859 	tty_encode_baud_rate(tty, baud, baud);
860 }
861 
862 
863 static void digi_break_ctl(struct tty_struct *tty, int break_state)
864 {
865 	struct usb_serial_port *port = tty->driver_data;
866 	unsigned char buf[4];
867 
868 	buf[0] = DIGI_CMD_BREAK_CONTROL;
869 	buf[1] = 2;				/* length */
870 	buf[2] = break_state ? 1 : 0;
871 	buf[3] = 0;				/* pad */
872 	digi_write_inb_command(port, buf, 4, 0);
873 }
874 
875 
876 static int digi_tiocmget(struct tty_struct *tty)
877 {
878 	struct usb_serial_port *port = tty->driver_data;
879 	struct digi_port *priv = usb_get_serial_port_data(port);
880 	unsigned int val;
881 	unsigned long flags;
882 
883 	spin_lock_irqsave(&priv->dp_port_lock, flags);
884 	val = priv->dp_modem_signals;
885 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
886 	return val;
887 }
888 
889 
890 static int digi_tiocmset(struct tty_struct *tty,
891 					unsigned int set, unsigned int clear)
892 {
893 	struct usb_serial_port *port = tty->driver_data;
894 	struct digi_port *priv = usb_get_serial_port_data(port);
895 	unsigned int val;
896 	unsigned long flags;
897 
898 	spin_lock_irqsave(&priv->dp_port_lock, flags);
899 	val = (priv->dp_modem_signals & ~clear) | set;
900 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
901 	return digi_set_modem_signals(port, val, 1);
902 }
903 
904 
905 static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
906 					const unsigned char *buf, int count)
907 {
908 
909 	int ret, data_len, new_len;
910 	struct digi_port *priv = usb_get_serial_port_data(port);
911 	unsigned char *data = port->write_urb->transfer_buffer;
912 	unsigned long flags = 0;
913 
914 	dev_dbg(&port->dev,
915 		"digi_write: TOP: port=%d, count=%d, in_interrupt=%ld\n",
916 		priv->dp_port_num, count, in_interrupt());
917 
918 	/* copy user data (which can sleep) before getting spin lock */
919 	count = min(count, port->bulk_out_size-2);
920 	count = min(64, count);
921 
922 	/* be sure only one write proceeds at a time */
923 	/* there are races on the port private buffer */
924 	spin_lock_irqsave(&priv->dp_port_lock, flags);
925 
926 	/* wait for urb status clear to submit another urb */
927 	if (priv->dp_write_urb_in_use) {
928 		/* buffer data if count is 1 (probably put_char) if possible */
929 		if (count == 1 && priv->dp_out_buf_len < DIGI_OUT_BUF_SIZE) {
930 			priv->dp_out_buf[priv->dp_out_buf_len++] = *buf;
931 			new_len = 1;
932 		} else {
933 			new_len = 0;
934 		}
935 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
936 		return new_len;
937 	}
938 
939 	/* allow space for any buffered data and for new data, up to */
940 	/* transfer buffer size - 2 (for command and length bytes) */
941 	new_len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
942 	data_len = new_len + priv->dp_out_buf_len;
943 
944 	if (data_len == 0) {
945 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
946 		return 0;
947 	}
948 
949 	port->write_urb->transfer_buffer_length = data_len+2;
950 
951 	*data++ = DIGI_CMD_SEND_DATA;
952 	*data++ = data_len;
953 
954 	/* copy in buffered data first */
955 	memcpy(data, priv->dp_out_buf, priv->dp_out_buf_len);
956 	data += priv->dp_out_buf_len;
957 
958 	/* copy in new data */
959 	memcpy(data, buf, new_len);
960 
961 	ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
962 	if (ret == 0) {
963 		priv->dp_write_urb_in_use = 1;
964 		ret = new_len;
965 		priv->dp_out_buf_len = 0;
966 	}
967 
968 	/* return length of new data written, or error */
969 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
970 	if (ret < 0)
971 		dev_err_console(port,
972 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
973 			__func__, ret, priv->dp_port_num);
974 	dev_dbg(&port->dev, "digi_write: returning %d\n", ret);
975 	return ret;
976 
977 }
978 
979 static void digi_write_bulk_callback(struct urb *urb)
980 {
981 
982 	struct usb_serial_port *port = urb->context;
983 	struct usb_serial *serial;
984 	struct digi_port *priv;
985 	struct digi_serial *serial_priv;
986 	int ret = 0;
987 	int status = urb->status;
988 
989 	/* port and serial sanity check */
990 	if (port == NULL || (priv = usb_get_serial_port_data(port)) == NULL) {
991 		pr_err("%s: port or port->private is NULL, status=%d\n",
992 			__func__, status);
993 		return;
994 	}
995 	serial = port->serial;
996 	if (serial == NULL || (serial_priv = usb_get_serial_data(serial)) == NULL) {
997 		dev_err(&port->dev,
998 			"%s: serial or serial->private is NULL, status=%d\n",
999 			__func__, status);
1000 		return;
1001 	}
1002 
1003 	/* handle oob callback */
1004 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1005 		dev_dbg(&port->dev, "digi_write_bulk_callback: oob callback\n");
1006 		spin_lock(&priv->dp_port_lock);
1007 		priv->dp_write_urb_in_use = 0;
1008 		wake_up_interruptible(&port->write_wait);
1009 		spin_unlock(&priv->dp_port_lock);
1010 		return;
1011 	}
1012 
1013 	/* try to send any buffered data on this port */
1014 	spin_lock(&priv->dp_port_lock);
1015 	priv->dp_write_urb_in_use = 0;
1016 	if (priv->dp_out_buf_len > 0) {
1017 		*((unsigned char *)(port->write_urb->transfer_buffer))
1018 			= (unsigned char)DIGI_CMD_SEND_DATA;
1019 		*((unsigned char *)(port->write_urb->transfer_buffer) + 1)
1020 			= (unsigned char)priv->dp_out_buf_len;
1021 		port->write_urb->transfer_buffer_length =
1022 						priv->dp_out_buf_len + 2;
1023 		memcpy(port->write_urb->transfer_buffer + 2, priv->dp_out_buf,
1024 			priv->dp_out_buf_len);
1025 		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1026 		if (ret == 0) {
1027 			priv->dp_write_urb_in_use = 1;
1028 			priv->dp_out_buf_len = 0;
1029 		}
1030 	}
1031 	/* wake up processes sleeping on writes immediately */
1032 	tty_port_tty_wakeup(&port->port);
1033 	/* also queue up a wakeup at scheduler time, in case we */
1034 	/* lost the race in write_chan(). */
1035 	schedule_work(&priv->dp_wakeup_work);
1036 
1037 	spin_unlock(&priv->dp_port_lock);
1038 	if (ret && ret != -EPERM)
1039 		dev_err_console(port,
1040 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
1041 			__func__, ret, priv->dp_port_num);
1042 }
1043 
1044 static int digi_write_room(struct tty_struct *tty)
1045 {
1046 	struct usb_serial_port *port = tty->driver_data;
1047 	struct digi_port *priv = usb_get_serial_port_data(port);
1048 	int room;
1049 	unsigned long flags = 0;
1050 
1051 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1052 
1053 	if (priv->dp_write_urb_in_use)
1054 		room = 0;
1055 	else
1056 		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;
1057 
1058 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1059 	dev_dbg(&port->dev, "digi_write_room: port=%d, room=%d\n", priv->dp_port_num, room);
1060 	return room;
1061 
1062 }
1063 
1064 static int digi_chars_in_buffer(struct tty_struct *tty)
1065 {
1066 	struct usb_serial_port *port = tty->driver_data;
1067 	struct digi_port *priv = usb_get_serial_port_data(port);
1068 
1069 	if (priv->dp_write_urb_in_use) {
1070 		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
1071 			priv->dp_port_num, port->bulk_out_size - 2);
1072 		/* return(port->bulk_out_size - 2); */
1073 		return 256;
1074 	} else {
1075 		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
1076 			priv->dp_port_num, priv->dp_out_buf_len);
1077 		return priv->dp_out_buf_len;
1078 	}
1079 
1080 }
1081 
1082 static void digi_dtr_rts(struct usb_serial_port *port, int on)
1083 {
1084 	/* Adjust DTR and RTS */
1085 	digi_set_modem_signals(port, on * (TIOCM_DTR|TIOCM_RTS), 1);
1086 }
1087 
1088 static int digi_open(struct tty_struct *tty, struct usb_serial_port *port)
1089 {
1090 	int ret;
1091 	unsigned char buf[32];
1092 	struct digi_port *priv = usb_get_serial_port_data(port);
1093 	struct ktermios not_termios;
1094 
1095 	/* be sure the device is started up */
1096 	if (digi_startup_device(port->serial) != 0)
1097 		return -ENXIO;
1098 
1099 	/* read modem signals automatically whenever they change */
1100 	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
1101 	buf[1] = priv->dp_port_num;
1102 	buf[2] = DIGI_ENABLE;
1103 	buf[3] = 0;
1104 
1105 	/* flush fifos */
1106 	buf[4] = DIGI_CMD_IFLUSH_FIFO;
1107 	buf[5] = priv->dp_port_num;
1108 	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1109 	buf[7] = 0;
1110 
1111 	ret = digi_write_oob_command(port, buf, 8, 1);
1112 	if (ret != 0)
1113 		dev_dbg(&port->dev, "digi_open: write oob failed, ret=%d\n", ret);
1114 
1115 	/* set termios settings */
1116 	if (tty) {
1117 		not_termios.c_cflag = ~tty->termios.c_cflag;
1118 		not_termios.c_iflag = ~tty->termios.c_iflag;
1119 		digi_set_termios(tty, port, &not_termios);
1120 	}
1121 	return 0;
1122 }
1123 
1124 
1125 static void digi_close(struct usb_serial_port *port)
1126 {
1127 	DEFINE_WAIT(wait);
1128 	int ret;
1129 	unsigned char buf[32];
1130 	struct digi_port *priv = usb_get_serial_port_data(port);
1131 
1132 	mutex_lock(&port->serial->disc_mutex);
1133 	/* if disconnected, just clear flags */
1134 	if (port->serial->disconnected)
1135 		goto exit;
1136 
1137 	/* FIXME: Transmit idle belongs in the wait_unti_sent path */
1138 	digi_transmit_idle(port, DIGI_CLOSE_TIMEOUT);
1139 
1140 	/* disable input flow control */
1141 	buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
1142 	buf[1] = priv->dp_port_num;
1143 	buf[2] = DIGI_DISABLE;
1144 	buf[3] = 0;
1145 
1146 	/* disable output flow control */
1147 	buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
1148 	buf[5] = priv->dp_port_num;
1149 	buf[6] = DIGI_DISABLE;
1150 	buf[7] = 0;
1151 
1152 	/* disable reading modem signals automatically */
1153 	buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
1154 	buf[9] = priv->dp_port_num;
1155 	buf[10] = DIGI_DISABLE;
1156 	buf[11] = 0;
1157 
1158 	/* disable receive */
1159 	buf[12] = DIGI_CMD_RECEIVE_ENABLE;
1160 	buf[13] = priv->dp_port_num;
1161 	buf[14] = DIGI_DISABLE;
1162 	buf[15] = 0;
1163 
1164 	/* flush fifos */
1165 	buf[16] = DIGI_CMD_IFLUSH_FIFO;
1166 	buf[17] = priv->dp_port_num;
1167 	buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1168 	buf[19] = 0;
1169 
1170 	ret = digi_write_oob_command(port, buf, 20, 0);
1171 	if (ret != 0)
1172 		dev_dbg(&port->dev, "digi_close: write oob failed, ret=%d\n",
1173 									ret);
1174 	/* wait for final commands on oob port to complete */
1175 	prepare_to_wait(&priv->dp_flush_wait, &wait,
1176 			TASK_INTERRUPTIBLE);
1177 	schedule_timeout(DIGI_CLOSE_TIMEOUT);
1178 	finish_wait(&priv->dp_flush_wait, &wait);
1179 
1180 	/* shutdown any outstanding bulk writes */
1181 	usb_kill_urb(port->write_urb);
1182 exit:
1183 	spin_lock_irq(&priv->dp_port_lock);
1184 	priv->dp_write_urb_in_use = 0;
1185 	wake_up_interruptible(&priv->dp_close_wait);
1186 	spin_unlock_irq(&priv->dp_port_lock);
1187 	mutex_unlock(&port->serial->disc_mutex);
1188 }
1189 
1190 
1191 /*
1192  *  Digi Startup Device
1193  *
1194  *  Starts reads on all ports.  Must be called AFTER startup, with
1195  *  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
1196  */
1197 
1198 static int digi_startup_device(struct usb_serial *serial)
1199 {
1200 	int i, ret = 0;
1201 	struct digi_serial *serial_priv = usb_get_serial_data(serial);
1202 	struct usb_serial_port *port;
1203 
1204 	/* be sure this happens exactly once */
1205 	spin_lock(&serial_priv->ds_serial_lock);
1206 	if (serial_priv->ds_device_started) {
1207 		spin_unlock(&serial_priv->ds_serial_lock);
1208 		return 0;
1209 	}
1210 	serial_priv->ds_device_started = 1;
1211 	spin_unlock(&serial_priv->ds_serial_lock);
1212 
1213 	/* start reading from each bulk in endpoint for the device */
1214 	/* set USB_DISABLE_SPD flag for write bulk urbs */
1215 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1216 		port = serial->port[i];
1217 		ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
1218 		if (ret != 0) {
1219 			dev_err(&port->dev,
1220 				"%s: usb_submit_urb failed, ret=%d, port=%d\n",
1221 				__func__, ret, i);
1222 			break;
1223 		}
1224 	}
1225 	return ret;
1226 }
1227 
1228 static int digi_port_init(struct usb_serial_port *port, unsigned port_num)
1229 {
1230 	struct digi_port *priv;
1231 
1232 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1233 	if (!priv)
1234 		return -ENOMEM;
1235 
1236 	spin_lock_init(&priv->dp_port_lock);
1237 	priv->dp_port_num = port_num;
1238 	init_waitqueue_head(&priv->dp_transmit_idle_wait);
1239 	init_waitqueue_head(&priv->dp_flush_wait);
1240 	init_waitqueue_head(&priv->dp_close_wait);
1241 	INIT_WORK(&priv->dp_wakeup_work, digi_wakeup_write_lock);
1242 	priv->dp_port = port;
1243 
1244 	init_waitqueue_head(&port->write_wait);
1245 
1246 	usb_set_serial_port_data(port, priv);
1247 
1248 	return 0;
1249 }
1250 
1251 static int digi_startup(struct usb_serial *serial)
1252 {
1253 	struct device *dev = &serial->interface->dev;
1254 	struct digi_serial *serial_priv;
1255 	int ret;
1256 	int i;
1257 
1258 	/* check whether the device has the expected number of endpoints */
1259 	if (serial->num_port_pointers < serial->type->num_ports + 1) {
1260 		dev_err(dev, "OOB endpoints missing\n");
1261 		return -ENODEV;
1262 	}
1263 
1264 	for (i = 0; i < serial->type->num_ports + 1 ; i++) {
1265 		if (!serial->port[i]->read_urb) {
1266 			dev_err(dev, "bulk-in endpoint missing\n");
1267 			return -ENODEV;
1268 		}
1269 		if (!serial->port[i]->write_urb) {
1270 			dev_err(dev, "bulk-out endpoint missing\n");
1271 			return -ENODEV;
1272 		}
1273 	}
1274 
1275 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
1276 	if (!serial_priv)
1277 		return -ENOMEM;
1278 
1279 	spin_lock_init(&serial_priv->ds_serial_lock);
1280 	serial_priv->ds_oob_port_num = serial->type->num_ports;
1281 	serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num];
1282 
1283 	ret = digi_port_init(serial_priv->ds_oob_port,
1284 						serial_priv->ds_oob_port_num);
1285 	if (ret) {
1286 		kfree(serial_priv);
1287 		return ret;
1288 	}
1289 
1290 	usb_set_serial_data(serial, serial_priv);
1291 
1292 	return 0;
1293 }
1294 
1295 
1296 static void digi_disconnect(struct usb_serial *serial)
1297 {
1298 	int i;
1299 
1300 	/* stop reads and writes on all ports */
1301 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1302 		usb_kill_urb(serial->port[i]->read_urb);
1303 		usb_kill_urb(serial->port[i]->write_urb);
1304 	}
1305 }
1306 
1307 
1308 static void digi_release(struct usb_serial *serial)
1309 {
1310 	struct digi_serial *serial_priv;
1311 	struct digi_port *priv;
1312 
1313 	serial_priv = usb_get_serial_data(serial);
1314 
1315 	priv = usb_get_serial_port_data(serial_priv->ds_oob_port);
1316 	kfree(priv);
1317 
1318 	kfree(serial_priv);
1319 }
1320 
1321 static int digi_port_probe(struct usb_serial_port *port)
1322 {
1323 	return digi_port_init(port, port->port_number);
1324 }
1325 
1326 static int digi_port_remove(struct usb_serial_port *port)
1327 {
1328 	struct digi_port *priv;
1329 
1330 	priv = usb_get_serial_port_data(port);
1331 	kfree(priv);
1332 
1333 	return 0;
1334 }
1335 
1336 static void digi_read_bulk_callback(struct urb *urb)
1337 {
1338 	struct usb_serial_port *port = urb->context;
1339 	struct digi_port *priv;
1340 	struct digi_serial *serial_priv;
1341 	int ret;
1342 	int status = urb->status;
1343 
1344 	/* port sanity check, do not resubmit if port is not valid */
1345 	if (port == NULL)
1346 		return;
1347 	priv = usb_get_serial_port_data(port);
1348 	if (priv == NULL) {
1349 		dev_err(&port->dev, "%s: port->private is NULL, status=%d\n",
1350 			__func__, status);
1351 		return;
1352 	}
1353 	if (port->serial == NULL ||
1354 		(serial_priv = usb_get_serial_data(port->serial)) == NULL) {
1355 		dev_err(&port->dev, "%s: serial is bad or serial->private "
1356 			"is NULL, status=%d\n", __func__, status);
1357 		return;
1358 	}
1359 
1360 	/* do not resubmit urb if it has any status error */
1361 	if (status) {
1362 		dev_err(&port->dev,
1363 			"%s: nonzero read bulk status: status=%d, port=%d\n",
1364 			__func__, status, priv->dp_port_num);
1365 		return;
1366 	}
1367 
1368 	/* handle oob or inb callback, do not resubmit if error */
1369 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1370 		if (digi_read_oob_callback(urb) != 0)
1371 			return;
1372 	} else {
1373 		if (digi_read_inb_callback(urb) != 0)
1374 			return;
1375 	}
1376 
1377 	/* continue read */
1378 	ret = usb_submit_urb(urb, GFP_ATOMIC);
1379 	if (ret != 0 && ret != -EPERM) {
1380 		dev_err(&port->dev,
1381 			"%s: failed resubmitting urb, ret=%d, port=%d\n",
1382 			__func__, ret, priv->dp_port_num);
1383 	}
1384 
1385 }
1386 
1387 /*
1388  *  Digi Read INB Callback
1389  *
1390  *  Digi Read INB Callback handles reads on the in band ports, sending
1391  *  the data on to the tty subsystem.  When called we know port and
1392  *  port->private are not NULL and port->serial has been validated.
1393  *  It returns 0 if successful, 1 if successful but the port is
1394  *  throttled, and -1 if the sanity checks failed.
1395  */
1396 
1397 static int digi_read_inb_callback(struct urb *urb)
1398 {
1399 	struct usb_serial_port *port = urb->context;
1400 	struct digi_port *priv = usb_get_serial_port_data(port);
1401 	int opcode = ((unsigned char *)urb->transfer_buffer)[0];
1402 	int len = ((unsigned char *)urb->transfer_buffer)[1];
1403 	int port_status = ((unsigned char *)urb->transfer_buffer)[2];
1404 	unsigned char *data = ((unsigned char *)urb->transfer_buffer) + 3;
1405 	int flag, throttled;
1406 	int status = urb->status;
1407 
1408 	/* do not process callbacks on closed ports */
1409 	/* but do continue the read chain */
1410 	if (urb->status == -ENOENT)
1411 		return 0;
1412 
1413 	/* short/multiple packet check */
1414 	if (urb->actual_length != len + 2) {
1415 		dev_err(&port->dev, "%s: INCOMPLETE OR MULTIPLE PACKET, "
1416 			"status=%d, port=%d, opcode=%d, len=%d, "
1417 			"actual_length=%d, status=%d\n", __func__, status,
1418 			priv->dp_port_num, opcode, len, urb->actual_length,
1419 			port_status);
1420 		return -1;
1421 	}
1422 
1423 	spin_lock(&priv->dp_port_lock);
1424 
1425 	/* check for throttle; if set, do not resubmit read urb */
1426 	/* indicate the read chain needs to be restarted on unthrottle */
1427 	throttled = priv->dp_throttled;
1428 	if (throttled)
1429 		priv->dp_throttle_restart = 1;
1430 
1431 	/* receive data */
1432 	if (opcode == DIGI_CMD_RECEIVE_DATA) {
1433 		/* get flag from port_status */
1434 		flag = 0;
1435 
1436 		/* overrun is special, not associated with a char */
1437 		if (port_status & DIGI_OVERRUN_ERROR)
1438 			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1439 
1440 		/* break takes precedence over parity, */
1441 		/* which takes precedence over framing errors */
1442 		if (port_status & DIGI_BREAK_ERROR)
1443 			flag = TTY_BREAK;
1444 		else if (port_status & DIGI_PARITY_ERROR)
1445 			flag = TTY_PARITY;
1446 		else if (port_status & DIGI_FRAMING_ERROR)
1447 			flag = TTY_FRAME;
1448 
1449 		/* data length is len-1 (one byte of len is port_status) */
1450 		--len;
1451 		if (len > 0) {
1452 			tty_insert_flip_string_fixed_flag(&port->port, data,
1453 					flag, len);
1454 			tty_flip_buffer_push(&port->port);
1455 		}
1456 	}
1457 	spin_unlock(&priv->dp_port_lock);
1458 
1459 	if (opcode == DIGI_CMD_RECEIVE_DISABLE)
1460 		dev_dbg(&port->dev, "%s: got RECEIVE_DISABLE\n", __func__);
1461 	else if (opcode != DIGI_CMD_RECEIVE_DATA)
1462 		dev_dbg(&port->dev, "%s: unknown opcode: %d\n", __func__, opcode);
1463 
1464 	return throttled ? 1 : 0;
1465 
1466 }
1467 
1468 
1469 /*
1470  *  Digi Read OOB Callback
1471  *
1472  *  Digi Read OOB Callback handles reads on the out of band port.
1473  *  When called we know port and port->private are not NULL and
1474  *  the port->serial is valid.  It returns 0 if successful, and
1475  *  -1 if the sanity checks failed.
1476  */
1477 
1478 static int digi_read_oob_callback(struct urb *urb)
1479 {
1480 
1481 	struct usb_serial_port *port = urb->context;
1482 	struct usb_serial *serial = port->serial;
1483 	struct tty_struct *tty;
1484 	struct digi_port *priv = usb_get_serial_port_data(port);
1485 	int opcode, line, status, val;
1486 	int i;
1487 	unsigned int rts;
1488 
1489 	/* handle each oob command */
1490 	for (i = 0; i < urb->actual_length - 3;) {
1491 		opcode = ((unsigned char *)urb->transfer_buffer)[i++];
1492 		line = ((unsigned char *)urb->transfer_buffer)[i++];
1493 		status = ((unsigned char *)urb->transfer_buffer)[i++];
1494 		val = ((unsigned char *)urb->transfer_buffer)[i++];
1495 
1496 		dev_dbg(&port->dev, "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d\n",
1497 			opcode, line, status, val);
1498 
1499 		if (status != 0 || line >= serial->type->num_ports)
1500 			continue;
1501 
1502 		port = serial->port[line];
1503 
1504 		priv = usb_get_serial_port_data(port);
1505 		if (priv == NULL)
1506 			return -1;
1507 
1508 		tty = tty_port_tty_get(&port->port);
1509 
1510 		rts = 0;
1511 		if (tty)
1512 			rts = C_CRTSCTS(tty);
1513 
1514 		if (tty && opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
1515 			spin_lock(&priv->dp_port_lock);
1516 			/* convert from digi flags to termiox flags */
1517 			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
1518 				priv->dp_modem_signals |= TIOCM_CTS;
1519 				/* port must be open to use tty struct */
1520 				if (rts)
1521 					tty_port_tty_wakeup(&port->port);
1522 			} else {
1523 				priv->dp_modem_signals &= ~TIOCM_CTS;
1524 				/* port must be open to use tty struct */
1525 			}
1526 			if (val & DIGI_READ_INPUT_SIGNALS_DSR)
1527 				priv->dp_modem_signals |= TIOCM_DSR;
1528 			else
1529 				priv->dp_modem_signals &= ~TIOCM_DSR;
1530 			if (val & DIGI_READ_INPUT_SIGNALS_RI)
1531 				priv->dp_modem_signals |= TIOCM_RI;
1532 			else
1533 				priv->dp_modem_signals &= ~TIOCM_RI;
1534 			if (val & DIGI_READ_INPUT_SIGNALS_DCD)
1535 				priv->dp_modem_signals |= TIOCM_CD;
1536 			else
1537 				priv->dp_modem_signals &= ~TIOCM_CD;
1538 
1539 			spin_unlock(&priv->dp_port_lock);
1540 		} else if (opcode == DIGI_CMD_TRANSMIT_IDLE) {
1541 			spin_lock(&priv->dp_port_lock);
1542 			priv->dp_transmit_idle = 1;
1543 			wake_up_interruptible(&priv->dp_transmit_idle_wait);
1544 			spin_unlock(&priv->dp_port_lock);
1545 		} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
1546 			wake_up_interruptible(&priv->dp_flush_wait);
1547 		}
1548 		tty_kref_put(tty);
1549 	}
1550 	return 0;
1551 
1552 }
1553 
1554 module_usb_serial_driver(serial_drivers, id_table_combined);
1555 
1556 MODULE_AUTHOR(DRIVER_AUTHOR);
1557 MODULE_DESCRIPTION(DRIVER_DESC);
1558 MODULE_LICENSE("GPL");
1559