1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 *  Digi AccelePort USB-4 and USB-2 Serial Converters
4 *
5 *  Copyright 2000 by Digi International
6 *
7 *  Shamelessly based on Brian Warner's keyspan_pda.c and Greg Kroah-Hartman's
8 *  usb-serial driver.
9 *
10 *  Peter Berger (pberger@brimson.com)
11 *  Al Borchers (borchers@steinerpoint.com)
12 */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/tty_driver.h>
19 #include <linux/tty_flip.h>
20 #include <linux/module.h>
21 #include <linux/spinlock.h>
22 #include <linux/workqueue.h>
23 #include <linux/uaccess.h>
24 #include <linux/usb.h>
25 #include <linux/wait.h>
26 #include <linux/sched/signal.h>
27 #include <linux/usb/serial.h>
28 
29 /* Defines */
30 
31 #define DRIVER_AUTHOR "Peter Berger <pberger@brimson.com>, Al Borchers <borchers@steinerpoint.com>"
32 #define DRIVER_DESC "Digi AccelePort USB-2/USB-4 Serial Converter driver"
33 
34 /* port output buffer length -- must be <= transfer buffer length - 2 */
35 /* so we can be sure to send the full buffer in one urb */
36 #define DIGI_OUT_BUF_SIZE		8
37 
38 /* port input buffer length -- must be >= transfer buffer length - 3 */
39 /* so we can be sure to hold at least one full buffer from one urb */
40 #define DIGI_IN_BUF_SIZE		64
41 
42 /* retry timeout while sleeping */
43 #define DIGI_RETRY_TIMEOUT		(HZ/10)
44 
45 /* timeout while waiting for tty output to drain in close */
46 /* this delay is used twice in close, so the total delay could */
47 /* be twice this value */
48 #define DIGI_CLOSE_TIMEOUT		(5*HZ)
49 
50 
51 /* AccelePort USB Defines */
52 
53 /* ids */
54 #define DIGI_VENDOR_ID			0x05c5
55 #define DIGI_2_ID			0x0002	/* USB-2 */
56 #define DIGI_4_ID			0x0004	/* USB-4 */
57 
58 /* commands
59  * "INB": can be used on the in-band endpoint
60  * "OOB": can be used on the out-of-band endpoint
61  */
62 #define DIGI_CMD_SET_BAUD_RATE			0	/* INB, OOB */
63 #define DIGI_CMD_SET_WORD_SIZE			1	/* INB, OOB */
64 #define DIGI_CMD_SET_PARITY			2	/* INB, OOB */
65 #define DIGI_CMD_SET_STOP_BITS			3	/* INB, OOB */
66 #define DIGI_CMD_SET_INPUT_FLOW_CONTROL		4	/* INB, OOB */
67 #define DIGI_CMD_SET_OUTPUT_FLOW_CONTROL	5	/* INB, OOB */
68 #define DIGI_CMD_SET_DTR_SIGNAL			6	/* INB, OOB */
69 #define DIGI_CMD_SET_RTS_SIGNAL			7	/* INB, OOB */
70 #define DIGI_CMD_READ_INPUT_SIGNALS		8	/*      OOB */
71 #define DIGI_CMD_IFLUSH_FIFO			9	/*      OOB */
72 #define DIGI_CMD_RECEIVE_ENABLE			10	/* INB, OOB */
73 #define DIGI_CMD_BREAK_CONTROL			11	/* INB, OOB */
74 #define DIGI_CMD_LOCAL_LOOPBACK			12	/* INB, OOB */
75 #define DIGI_CMD_TRANSMIT_IDLE			13	/* INB, OOB */
76 #define DIGI_CMD_READ_UART_REGISTER		14	/*      OOB */
77 #define DIGI_CMD_WRITE_UART_REGISTER		15	/* INB, OOB */
78 #define DIGI_CMD_AND_UART_REGISTER		16	/* INB, OOB */
79 #define DIGI_CMD_OR_UART_REGISTER		17	/* INB, OOB */
80 #define DIGI_CMD_SEND_DATA			18	/* INB      */
81 #define DIGI_CMD_RECEIVE_DATA			19	/* INB      */
82 #define DIGI_CMD_RECEIVE_DISABLE		20	/* INB      */
83 #define DIGI_CMD_GET_PORT_TYPE			21	/*      OOB */
84 
85 /* baud rates */
86 #define DIGI_BAUD_50				0
87 #define DIGI_BAUD_75				1
88 #define DIGI_BAUD_110				2
89 #define DIGI_BAUD_150				3
90 #define DIGI_BAUD_200				4
91 #define DIGI_BAUD_300				5
92 #define DIGI_BAUD_600				6
93 #define DIGI_BAUD_1200				7
94 #define DIGI_BAUD_1800				8
95 #define DIGI_BAUD_2400				9
96 #define DIGI_BAUD_4800				10
97 #define DIGI_BAUD_7200				11
98 #define DIGI_BAUD_9600				12
99 #define DIGI_BAUD_14400				13
100 #define DIGI_BAUD_19200				14
101 #define DIGI_BAUD_28800				15
102 #define DIGI_BAUD_38400				16
103 #define DIGI_BAUD_57600				17
104 #define DIGI_BAUD_76800				18
105 #define DIGI_BAUD_115200			19
106 #define DIGI_BAUD_153600			20
107 #define DIGI_BAUD_230400			21
108 #define DIGI_BAUD_460800			22
109 
110 /* arguments */
111 #define DIGI_WORD_SIZE_5			0
112 #define DIGI_WORD_SIZE_6			1
113 #define DIGI_WORD_SIZE_7			2
114 #define DIGI_WORD_SIZE_8			3
115 
116 #define DIGI_PARITY_NONE			0
117 #define DIGI_PARITY_ODD				1
118 #define DIGI_PARITY_EVEN			2
119 #define DIGI_PARITY_MARK			3
120 #define DIGI_PARITY_SPACE			4
121 
122 #define DIGI_STOP_BITS_1			0
123 #define DIGI_STOP_BITS_2			1
124 
125 #define DIGI_INPUT_FLOW_CONTROL_XON_XOFF	1
126 #define DIGI_INPUT_FLOW_CONTROL_RTS		2
127 #define DIGI_INPUT_FLOW_CONTROL_DTR		4
128 
129 #define DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF	1
130 #define DIGI_OUTPUT_FLOW_CONTROL_CTS		2
131 #define DIGI_OUTPUT_FLOW_CONTROL_DSR		4
132 
133 #define DIGI_DTR_INACTIVE			0
134 #define DIGI_DTR_ACTIVE				1
135 #define DIGI_DTR_INPUT_FLOW_CONTROL		2
136 
137 #define DIGI_RTS_INACTIVE			0
138 #define DIGI_RTS_ACTIVE				1
139 #define DIGI_RTS_INPUT_FLOW_CONTROL		2
140 #define DIGI_RTS_TOGGLE				3
141 
142 #define DIGI_FLUSH_TX				1
143 #define DIGI_FLUSH_RX				2
144 #define DIGI_RESUME_TX				4 /* clears xoff condition */
145 
146 #define DIGI_TRANSMIT_NOT_IDLE			0
147 #define DIGI_TRANSMIT_IDLE			1
148 
149 #define DIGI_DISABLE				0
150 #define DIGI_ENABLE				1
151 
152 #define DIGI_DEASSERT				0
153 #define DIGI_ASSERT				1
154 
155 /* in band status codes */
156 #define DIGI_OVERRUN_ERROR			4
157 #define DIGI_PARITY_ERROR			8
158 #define DIGI_FRAMING_ERROR			16
159 #define DIGI_BREAK_ERROR			32
160 
161 /* out of band status */
162 #define DIGI_NO_ERROR				0
163 #define DIGI_BAD_FIRST_PARAMETER		1
164 #define DIGI_BAD_SECOND_PARAMETER		2
165 #define DIGI_INVALID_LINE			3
166 #define DIGI_INVALID_OPCODE			4
167 
168 /* input signals */
169 #define DIGI_READ_INPUT_SIGNALS_SLOT		1
170 #define DIGI_READ_INPUT_SIGNALS_ERR		2
171 #define DIGI_READ_INPUT_SIGNALS_BUSY		4
172 #define DIGI_READ_INPUT_SIGNALS_PE		8
173 #define DIGI_READ_INPUT_SIGNALS_CTS		16
174 #define DIGI_READ_INPUT_SIGNALS_DSR		32
175 #define DIGI_READ_INPUT_SIGNALS_RI		64
176 #define DIGI_READ_INPUT_SIGNALS_DCD		128
177 
178 
179 /* Structures */
180 
181 struct digi_serial {
182 	spinlock_t ds_serial_lock;
183 	struct usb_serial_port *ds_oob_port;	/* out-of-band port */
184 	int ds_oob_port_num;			/* index of out-of-band port */
185 	int ds_device_started;
186 };
187 
188 struct digi_port {
189 	spinlock_t dp_port_lock;
190 	int dp_port_num;
191 	int dp_out_buf_len;
192 	unsigned char dp_out_buf[DIGI_OUT_BUF_SIZE];
193 	int dp_write_urb_in_use;
194 	unsigned int dp_modem_signals;
195 	int dp_transmit_idle;
196 	wait_queue_head_t dp_transmit_idle_wait;
197 	int dp_throttled;
198 	int dp_throttle_restart;
199 	wait_queue_head_t dp_flush_wait;
200 	wait_queue_head_t dp_close_wait;	/* wait queue for close */
201 	struct work_struct dp_wakeup_work;
202 	struct usb_serial_port *dp_port;
203 };
204 
205 
206 /* Local Function Declarations */
207 
208 static void digi_wakeup_write_lock(struct work_struct *work);
209 static int digi_write_oob_command(struct usb_serial_port *port,
210 	unsigned char *buf, int count, int interruptible);
211 static int digi_write_inb_command(struct usb_serial_port *port,
212 	unsigned char *buf, int count, unsigned long timeout);
213 static int digi_set_modem_signals(struct usb_serial_port *port,
214 	unsigned int modem_signals, int interruptible);
215 static int digi_transmit_idle(struct usb_serial_port *port,
216 	unsigned long timeout);
217 static void digi_rx_throttle(struct tty_struct *tty);
218 static void digi_rx_unthrottle(struct tty_struct *tty);
219 static void digi_set_termios(struct tty_struct *tty,
220 		struct usb_serial_port *port, struct ktermios *old_termios);
221 static void digi_break_ctl(struct tty_struct *tty, int break_state);
222 static int digi_tiocmget(struct tty_struct *tty);
223 static int digi_tiocmset(struct tty_struct *tty, unsigned int set,
224 		unsigned int clear);
225 static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
226 		const unsigned char *buf, int count);
227 static void digi_write_bulk_callback(struct urb *urb);
228 static int digi_write_room(struct tty_struct *tty);
229 static int digi_chars_in_buffer(struct tty_struct *tty);
230 static int digi_open(struct tty_struct *tty, struct usb_serial_port *port);
231 static void digi_close(struct usb_serial_port *port);
232 static void digi_dtr_rts(struct usb_serial_port *port, int on);
233 static int digi_startup_device(struct usb_serial *serial);
234 static int digi_startup(struct usb_serial *serial);
235 static void digi_disconnect(struct usb_serial *serial);
236 static void digi_release(struct usb_serial *serial);
237 static int digi_port_probe(struct usb_serial_port *port);
238 static int digi_port_remove(struct usb_serial_port *port);
239 static void digi_read_bulk_callback(struct urb *urb);
240 static int digi_read_inb_callback(struct urb *urb);
241 static int digi_read_oob_callback(struct urb *urb);
242 
243 
244 static const struct usb_device_id id_table_combined[] = {
245 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
246 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
247 	{ }						/* Terminating entry */
248 };
249 
250 static const struct usb_device_id id_table_2[] = {
251 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_2_ID) },
252 	{ }						/* Terminating entry */
253 };
254 
255 static const struct usb_device_id id_table_4[] = {
256 	{ USB_DEVICE(DIGI_VENDOR_ID, DIGI_4_ID) },
257 	{ }						/* Terminating entry */
258 };
259 
260 MODULE_DEVICE_TABLE(usb, id_table_combined);
261 
262 /* device info needed for the Digi serial converter */
263 
264 static struct usb_serial_driver digi_acceleport_2_device = {
265 	.driver = {
266 		.owner =		THIS_MODULE,
267 		.name =			"digi_2",
268 	},
269 	.description =			"Digi 2 port USB adapter",
270 	.id_table =			id_table_2,
271 	.num_ports =			3,
272 	.num_bulk_in =			4,
273 	.num_bulk_out =			4,
274 	.open =				digi_open,
275 	.close =			digi_close,
276 	.dtr_rts =			digi_dtr_rts,
277 	.write =			digi_write,
278 	.write_room =			digi_write_room,
279 	.write_bulk_callback = 		digi_write_bulk_callback,
280 	.read_bulk_callback =		digi_read_bulk_callback,
281 	.chars_in_buffer =		digi_chars_in_buffer,
282 	.throttle =			digi_rx_throttle,
283 	.unthrottle =			digi_rx_unthrottle,
284 	.set_termios =			digi_set_termios,
285 	.break_ctl =			digi_break_ctl,
286 	.tiocmget =			digi_tiocmget,
287 	.tiocmset =			digi_tiocmset,
288 	.attach =			digi_startup,
289 	.disconnect =			digi_disconnect,
290 	.release =			digi_release,
291 	.port_probe =			digi_port_probe,
292 	.port_remove =			digi_port_remove,
293 };
294 
295 static struct usb_serial_driver digi_acceleport_4_device = {
296 	.driver = {
297 		.owner =		THIS_MODULE,
298 		.name =			"digi_4",
299 	},
300 	.description =			"Digi 4 port USB adapter",
301 	.id_table =			id_table_4,
302 	.num_ports =			4,
303 	.num_bulk_in =			5,
304 	.num_bulk_out =			5,
305 	.open =				digi_open,
306 	.close =			digi_close,
307 	.write =			digi_write,
308 	.write_room =			digi_write_room,
309 	.write_bulk_callback = 		digi_write_bulk_callback,
310 	.read_bulk_callback =		digi_read_bulk_callback,
311 	.chars_in_buffer =		digi_chars_in_buffer,
312 	.throttle =			digi_rx_throttle,
313 	.unthrottle =			digi_rx_unthrottle,
314 	.set_termios =			digi_set_termios,
315 	.break_ctl =			digi_break_ctl,
316 	.tiocmget =			digi_tiocmget,
317 	.tiocmset =			digi_tiocmset,
318 	.attach =			digi_startup,
319 	.disconnect =			digi_disconnect,
320 	.release =			digi_release,
321 	.port_probe =			digi_port_probe,
322 	.port_remove =			digi_port_remove,
323 };
324 
325 static struct usb_serial_driver * const serial_drivers[] = {
326 	&digi_acceleport_2_device, &digi_acceleport_4_device, NULL
327 };
328 
329 /* Functions */
330 
331 /*
332  *  Cond Wait Interruptible Timeout Irqrestore
333  *
334  *  Do spin_unlock_irqrestore and interruptible_sleep_on_timeout
335  *  so that wake ups are not lost if they occur between the unlock
336  *  and the sleep.  In other words, spin_unlock_irqrestore and
337  *  interruptible_sleep_on_timeout are "atomic" with respect to
338  *  wake ups.  This is used to implement condition variables.
339  *
340  *  interruptible_sleep_on_timeout is deprecated and has been replaced
341  *  with the equivalent code.
342  */
343 
344 static long cond_wait_interruptible_timeout_irqrestore(
345 	wait_queue_head_t *q, long timeout,
346 	spinlock_t *lock, unsigned long flags)
347 __releases(lock)
348 {
349 	DEFINE_WAIT(wait);
350 
351 	prepare_to_wait(q, &wait, TASK_INTERRUPTIBLE);
352 	spin_unlock_irqrestore(lock, flags);
353 	timeout = schedule_timeout(timeout);
354 	finish_wait(q, &wait);
355 
356 	return timeout;
357 }
358 
359 
360 /*
361  *  Digi Wakeup Write
362  *
363  *  Wake up port, line discipline, and tty processes sleeping
364  *  on writes.
365  */
366 
367 static void digi_wakeup_write_lock(struct work_struct *work)
368 {
369 	struct digi_port *priv =
370 			container_of(work, struct digi_port, dp_wakeup_work);
371 	struct usb_serial_port *port = priv->dp_port;
372 	unsigned long flags;
373 
374 	spin_lock_irqsave(&priv->dp_port_lock, flags);
375 	tty_port_tty_wakeup(&port->port);
376 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
377 }
378 
379 /*
380  *  Digi Write OOB Command
381  *
382  *  Write commands on the out of band port.  Commands are 4
383  *  bytes each, multiple commands can be sent at once, and
384  *  no command will be split across USB packets.  Returns 0
385  *  if successful, -EINTR if interrupted while sleeping and
386  *  the interruptible flag is true, or a negative error
387  *  returned by usb_submit_urb.
388  */
389 
390 static int digi_write_oob_command(struct usb_serial_port *port,
391 	unsigned char *buf, int count, int interruptible)
392 {
393 	int ret = 0;
394 	int len;
395 	struct usb_serial_port *oob_port = (struct usb_serial_port *)((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
396 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
397 	unsigned long flags = 0;
398 
399 	dev_dbg(&port->dev,
400 		"digi_write_oob_command: TOP: port=%d, count=%d\n",
401 		oob_priv->dp_port_num, count);
402 
403 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
404 	while (count > 0) {
405 		while (oob_priv->dp_write_urb_in_use) {
406 			cond_wait_interruptible_timeout_irqrestore(
407 				&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
408 				&oob_priv->dp_port_lock, flags);
409 			if (interruptible && signal_pending(current))
410 				return -EINTR;
411 			spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
412 		}
413 
414 		/* len must be a multiple of 4, so commands are not split */
415 		len = min(count, oob_port->bulk_out_size);
416 		if (len > 4)
417 			len &= ~3;
418 		memcpy(oob_port->write_urb->transfer_buffer, buf, len);
419 		oob_port->write_urb->transfer_buffer_length = len;
420 		ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
421 		if (ret == 0) {
422 			oob_priv->dp_write_urb_in_use = 1;
423 			count -= len;
424 			buf += len;
425 		}
426 	}
427 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
428 	if (ret)
429 		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
430 			__func__, ret);
431 	return ret;
432 
433 }
434 
435 
436 /*
437  *  Digi Write In Band Command
438  *
439  *  Write commands on the given port.  Commands are 4
440  *  bytes each, multiple commands can be sent at once, and
441  *  no command will be split across USB packets.  If timeout
442  *  is non-zero, write in band command will return after
443  *  waiting unsuccessfully for the URB status to clear for
444  *  timeout ticks.  Returns 0 if successful, or a negative
445  *  error returned by digi_write.
446  */
447 
448 static int digi_write_inb_command(struct usb_serial_port *port,
449 	unsigned char *buf, int count, unsigned long timeout)
450 {
451 	int ret = 0;
452 	int len;
453 	struct digi_port *priv = usb_get_serial_port_data(port);
454 	unsigned char *data = port->write_urb->transfer_buffer;
455 	unsigned long flags = 0;
456 
457 	dev_dbg(&port->dev, "digi_write_inb_command: TOP: port=%d, count=%d\n",
458 		priv->dp_port_num, count);
459 
460 	if (timeout)
461 		timeout += jiffies;
462 	else
463 		timeout = ULONG_MAX;
464 
465 	spin_lock_irqsave(&priv->dp_port_lock, flags);
466 	while (count > 0 && ret == 0) {
467 		while (priv->dp_write_urb_in_use &&
468 		       time_before(jiffies, timeout)) {
469 			cond_wait_interruptible_timeout_irqrestore(
470 				&port->write_wait, DIGI_RETRY_TIMEOUT,
471 				&priv->dp_port_lock, flags);
472 			if (signal_pending(current))
473 				return -EINTR;
474 			spin_lock_irqsave(&priv->dp_port_lock, flags);
475 		}
476 
477 		/* len must be a multiple of 4 and small enough to */
478 		/* guarantee the write will send buffered data first, */
479 		/* so commands are in order with data and not split */
480 		len = min(count, port->bulk_out_size-2-priv->dp_out_buf_len);
481 		if (len > 4)
482 			len &= ~3;
483 
484 		/* write any buffered data first */
485 		if (priv->dp_out_buf_len > 0) {
486 			data[0] = DIGI_CMD_SEND_DATA;
487 			data[1] = priv->dp_out_buf_len;
488 			memcpy(data + 2, priv->dp_out_buf,
489 				priv->dp_out_buf_len);
490 			memcpy(data + 2 + priv->dp_out_buf_len, buf, len);
491 			port->write_urb->transfer_buffer_length
492 				= priv->dp_out_buf_len + 2 + len;
493 		} else {
494 			memcpy(data, buf, len);
495 			port->write_urb->transfer_buffer_length = len;
496 		}
497 
498 		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
499 		if (ret == 0) {
500 			priv->dp_write_urb_in_use = 1;
501 			priv->dp_out_buf_len = 0;
502 			count -= len;
503 			buf += len;
504 		}
505 
506 	}
507 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
508 
509 	if (ret)
510 		dev_err(&port->dev,
511 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
512 			__func__, ret, priv->dp_port_num);
513 	return ret;
514 }
515 
516 
517 /*
518  *  Digi Set Modem Signals
519  *
520  *  Sets or clears DTR and RTS on the port, according to the
521  *  modem_signals argument.  Use TIOCM_DTR and TIOCM_RTS flags
522  *  for the modem_signals argument.  Returns 0 if successful,
523  *  -EINTR if interrupted while sleeping, or a non-zero error
524  *  returned by usb_submit_urb.
525  */
526 
527 static int digi_set_modem_signals(struct usb_serial_port *port,
528 	unsigned int modem_signals, int interruptible)
529 {
530 
531 	int ret;
532 	struct digi_port *port_priv = usb_get_serial_port_data(port);
533 	struct usb_serial_port *oob_port = (struct usb_serial_port *) ((struct digi_serial *)(usb_get_serial_data(port->serial)))->ds_oob_port;
534 	struct digi_port *oob_priv = usb_get_serial_port_data(oob_port);
535 	unsigned char *data = oob_port->write_urb->transfer_buffer;
536 	unsigned long flags = 0;
537 
538 
539 	dev_dbg(&port->dev,
540 		"digi_set_modem_signals: TOP: port=%d, modem_signals=0x%x\n",
541 		port_priv->dp_port_num, modem_signals);
542 
543 	spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
544 	spin_lock(&port_priv->dp_port_lock);
545 
546 	while (oob_priv->dp_write_urb_in_use) {
547 		spin_unlock(&port_priv->dp_port_lock);
548 		cond_wait_interruptible_timeout_irqrestore(
549 			&oob_port->write_wait, DIGI_RETRY_TIMEOUT,
550 			&oob_priv->dp_port_lock, flags);
551 		if (interruptible && signal_pending(current))
552 			return -EINTR;
553 		spin_lock_irqsave(&oob_priv->dp_port_lock, flags);
554 		spin_lock(&port_priv->dp_port_lock);
555 	}
556 	data[0] = DIGI_CMD_SET_DTR_SIGNAL;
557 	data[1] = port_priv->dp_port_num;
558 	data[2] = (modem_signals & TIOCM_DTR) ?
559 					DIGI_DTR_ACTIVE : DIGI_DTR_INACTIVE;
560 	data[3] = 0;
561 	data[4] = DIGI_CMD_SET_RTS_SIGNAL;
562 	data[5] = port_priv->dp_port_num;
563 	data[6] = (modem_signals & TIOCM_RTS) ?
564 					DIGI_RTS_ACTIVE : DIGI_RTS_INACTIVE;
565 	data[7] = 0;
566 
567 	oob_port->write_urb->transfer_buffer_length = 8;
568 
569 	ret = usb_submit_urb(oob_port->write_urb, GFP_ATOMIC);
570 	if (ret == 0) {
571 		oob_priv->dp_write_urb_in_use = 1;
572 		port_priv->dp_modem_signals &= ~(TIOCM_DTR | TIOCM_RTS);
573 		port_priv->dp_modem_signals |=
574 				modem_signals & (TIOCM_DTR | TIOCM_RTS);
575 	}
576 	spin_unlock(&port_priv->dp_port_lock);
577 	spin_unlock_irqrestore(&oob_priv->dp_port_lock, flags);
578 	if (ret)
579 		dev_err(&port->dev, "%s: usb_submit_urb failed, ret=%d\n",
580 			__func__, ret);
581 	return ret;
582 }
583 
584 /*
585  *  Digi Transmit Idle
586  *
587  *  Digi transmit idle waits, up to timeout ticks, for the transmitter
588  *  to go idle.  It returns 0 if successful or a negative error.
589  *
590  *  There are race conditions here if more than one process is calling
591  *  digi_transmit_idle on the same port at the same time.  However, this
592  *  is only called from close, and only one process can be in close on a
593  *  port at a time, so its ok.
594  */
595 
596 static int digi_transmit_idle(struct usb_serial_port *port,
597 	unsigned long timeout)
598 {
599 	int ret;
600 	unsigned char buf[2];
601 	struct digi_port *priv = usb_get_serial_port_data(port);
602 	unsigned long flags = 0;
603 
604 	spin_lock_irqsave(&priv->dp_port_lock, flags);
605 	priv->dp_transmit_idle = 0;
606 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
607 
608 	buf[0] = DIGI_CMD_TRANSMIT_IDLE;
609 	buf[1] = 0;
610 
611 	timeout += jiffies;
612 
613 	ret = digi_write_inb_command(port, buf, 2, timeout - jiffies);
614 	if (ret != 0)
615 		return ret;
616 
617 	spin_lock_irqsave(&priv->dp_port_lock, flags);
618 
619 	while (time_before(jiffies, timeout) && !priv->dp_transmit_idle) {
620 		cond_wait_interruptible_timeout_irqrestore(
621 			&priv->dp_transmit_idle_wait, DIGI_RETRY_TIMEOUT,
622 			&priv->dp_port_lock, flags);
623 		if (signal_pending(current))
624 			return -EINTR;
625 		spin_lock_irqsave(&priv->dp_port_lock, flags);
626 	}
627 	priv->dp_transmit_idle = 0;
628 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
629 	return 0;
630 
631 }
632 
633 
634 static void digi_rx_throttle(struct tty_struct *tty)
635 {
636 	unsigned long flags;
637 	struct usb_serial_port *port = tty->driver_data;
638 	struct digi_port *priv = usb_get_serial_port_data(port);
639 
640 	/* stop receiving characters by not resubmitting the read urb */
641 	spin_lock_irqsave(&priv->dp_port_lock, flags);
642 	priv->dp_throttled = 1;
643 	priv->dp_throttle_restart = 0;
644 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
645 }
646 
647 
648 static void digi_rx_unthrottle(struct tty_struct *tty)
649 {
650 	int ret = 0;
651 	unsigned long flags;
652 	struct usb_serial_port *port = tty->driver_data;
653 	struct digi_port *priv = usb_get_serial_port_data(port);
654 
655 	spin_lock_irqsave(&priv->dp_port_lock, flags);
656 
657 	/* restart read chain */
658 	if (priv->dp_throttle_restart)
659 		ret = usb_submit_urb(port->read_urb, GFP_ATOMIC);
660 
661 	/* turn throttle off */
662 	priv->dp_throttled = 0;
663 	priv->dp_throttle_restart = 0;
664 
665 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
666 
667 	if (ret)
668 		dev_err(&port->dev,
669 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
670 			__func__, ret, priv->dp_port_num);
671 }
672 
673 
674 static void digi_set_termios(struct tty_struct *tty,
675 		struct usb_serial_port *port, struct ktermios *old_termios)
676 {
677 	struct digi_port *priv = usb_get_serial_port_data(port);
678 	struct device *dev = &port->dev;
679 	unsigned int iflag = tty->termios.c_iflag;
680 	unsigned int cflag = tty->termios.c_cflag;
681 	unsigned int old_iflag = old_termios->c_iflag;
682 	unsigned int old_cflag = old_termios->c_cflag;
683 	unsigned char buf[32];
684 	unsigned int modem_signals;
685 	int arg, ret;
686 	int i = 0;
687 	speed_t baud;
688 
689 	dev_dbg(dev,
690 		"digi_set_termios: TOP: port=%d, iflag=0x%x, old_iflag=0x%x, cflag=0x%x, old_cflag=0x%x\n",
691 		priv->dp_port_num, iflag, old_iflag, cflag, old_cflag);
692 
693 	/* set baud rate */
694 	baud = tty_get_baud_rate(tty);
695 	if (baud != tty_termios_baud_rate(old_termios)) {
696 		arg = -1;
697 
698 		/* reassert DTR and (maybe) RTS on transition from B0 */
699 		if ((old_cflag & CBAUD) == B0) {
700 			/* don't set RTS if using hardware flow control */
701 			/* and throttling input */
702 			modem_signals = TIOCM_DTR;
703 			if (!C_CRTSCTS(tty) || !tty_throttled(tty))
704 				modem_signals |= TIOCM_RTS;
705 			digi_set_modem_signals(port, modem_signals, 1);
706 		}
707 		switch (baud) {
708 		/* drop DTR and RTS on transition to B0 */
709 		case 0: digi_set_modem_signals(port, 0, 1); break;
710 		case 50: arg = DIGI_BAUD_50; break;
711 		case 75: arg = DIGI_BAUD_75; break;
712 		case 110: arg = DIGI_BAUD_110; break;
713 		case 150: arg = DIGI_BAUD_150; break;
714 		case 200: arg = DIGI_BAUD_200; break;
715 		case 300: arg = DIGI_BAUD_300; break;
716 		case 600: arg = DIGI_BAUD_600; break;
717 		case 1200: arg = DIGI_BAUD_1200; break;
718 		case 1800: arg = DIGI_BAUD_1800; break;
719 		case 2400: arg = DIGI_BAUD_2400; break;
720 		case 4800: arg = DIGI_BAUD_4800; break;
721 		case 9600: arg = DIGI_BAUD_9600; break;
722 		case 19200: arg = DIGI_BAUD_19200; break;
723 		case 38400: arg = DIGI_BAUD_38400; break;
724 		case 57600: arg = DIGI_BAUD_57600; break;
725 		case 115200: arg = DIGI_BAUD_115200; break;
726 		case 230400: arg = DIGI_BAUD_230400; break;
727 		case 460800: arg = DIGI_BAUD_460800; break;
728 		default:
729 			arg = DIGI_BAUD_9600;
730 			baud = 9600;
731 			break;
732 		}
733 		if (arg != -1) {
734 			buf[i++] = DIGI_CMD_SET_BAUD_RATE;
735 			buf[i++] = priv->dp_port_num;
736 			buf[i++] = arg;
737 			buf[i++] = 0;
738 		}
739 	}
740 	/* set parity */
741 	tty->termios.c_cflag &= ~CMSPAR;
742 
743 	if ((cflag & (PARENB | PARODD)) != (old_cflag & (PARENB | PARODD))) {
744 		if (cflag & PARENB) {
745 			if (cflag & PARODD)
746 				arg = DIGI_PARITY_ODD;
747 			else
748 				arg = DIGI_PARITY_EVEN;
749 		} else {
750 			arg = DIGI_PARITY_NONE;
751 		}
752 		buf[i++] = DIGI_CMD_SET_PARITY;
753 		buf[i++] = priv->dp_port_num;
754 		buf[i++] = arg;
755 		buf[i++] = 0;
756 	}
757 	/* set word size */
758 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
759 		arg = -1;
760 		switch (cflag & CSIZE) {
761 		case CS5: arg = DIGI_WORD_SIZE_5; break;
762 		case CS6: arg = DIGI_WORD_SIZE_6; break;
763 		case CS7: arg = DIGI_WORD_SIZE_7; break;
764 		case CS8: arg = DIGI_WORD_SIZE_8; break;
765 		default:
766 			dev_dbg(dev,
767 				"digi_set_termios: can't handle word size %d\n",
768 				cflag & CSIZE);
769 			break;
770 		}
771 
772 		if (arg != -1) {
773 			buf[i++] = DIGI_CMD_SET_WORD_SIZE;
774 			buf[i++] = priv->dp_port_num;
775 			buf[i++] = arg;
776 			buf[i++] = 0;
777 		}
778 
779 	}
780 
781 	/* set stop bits */
782 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
783 
784 		if ((cflag & CSTOPB))
785 			arg = DIGI_STOP_BITS_2;
786 		else
787 			arg = DIGI_STOP_BITS_1;
788 
789 		buf[i++] = DIGI_CMD_SET_STOP_BITS;
790 		buf[i++] = priv->dp_port_num;
791 		buf[i++] = arg;
792 		buf[i++] = 0;
793 
794 	}
795 
796 	/* set input flow control */
797 	if ((iflag & IXOFF) != (old_iflag & IXOFF) ||
798 			(cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
799 		arg = 0;
800 		if (iflag & IXOFF)
801 			arg |= DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
802 		else
803 			arg &= ~DIGI_INPUT_FLOW_CONTROL_XON_XOFF;
804 
805 		if (cflag & CRTSCTS) {
806 			arg |= DIGI_INPUT_FLOW_CONTROL_RTS;
807 
808 			/* On USB-4 it is necessary to assert RTS prior */
809 			/* to selecting RTS input flow control.  */
810 			buf[i++] = DIGI_CMD_SET_RTS_SIGNAL;
811 			buf[i++] = priv->dp_port_num;
812 			buf[i++] = DIGI_RTS_ACTIVE;
813 			buf[i++] = 0;
814 
815 		} else {
816 			arg &= ~DIGI_INPUT_FLOW_CONTROL_RTS;
817 		}
818 		buf[i++] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
819 		buf[i++] = priv->dp_port_num;
820 		buf[i++] = arg;
821 		buf[i++] = 0;
822 	}
823 
824 	/* set output flow control */
825 	if ((iflag & IXON) != (old_iflag & IXON) ||
826 			(cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
827 		arg = 0;
828 		if (iflag & IXON)
829 			arg |= DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
830 		else
831 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_XON_XOFF;
832 
833 		if (cflag & CRTSCTS)
834 			arg |= DIGI_OUTPUT_FLOW_CONTROL_CTS;
835 		else
836 			arg &= ~DIGI_OUTPUT_FLOW_CONTROL_CTS;
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 	unsigned long flags;
987 	int ret = 0;
988 	int status = urb->status;
989 
990 	/* port and serial sanity check */
991 	if (port == NULL || (priv = usb_get_serial_port_data(port)) == NULL) {
992 		pr_err("%s: port or port->private is NULL, status=%d\n",
993 			__func__, status);
994 		return;
995 	}
996 	serial = port->serial;
997 	if (serial == NULL || (serial_priv = usb_get_serial_data(serial)) == NULL) {
998 		dev_err(&port->dev,
999 			"%s: serial or serial->private is NULL, status=%d\n",
1000 			__func__, status);
1001 		return;
1002 	}
1003 
1004 	/* handle oob callback */
1005 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1006 		dev_dbg(&port->dev, "digi_write_bulk_callback: oob callback\n");
1007 		spin_lock_irqsave(&priv->dp_port_lock, flags);
1008 		priv->dp_write_urb_in_use = 0;
1009 		wake_up_interruptible(&port->write_wait);
1010 		spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1011 		return;
1012 	}
1013 
1014 	/* try to send any buffered data on this port */
1015 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1016 	priv->dp_write_urb_in_use = 0;
1017 	if (priv->dp_out_buf_len > 0) {
1018 		*((unsigned char *)(port->write_urb->transfer_buffer))
1019 			= (unsigned char)DIGI_CMD_SEND_DATA;
1020 		*((unsigned char *)(port->write_urb->transfer_buffer) + 1)
1021 			= (unsigned char)priv->dp_out_buf_len;
1022 		port->write_urb->transfer_buffer_length =
1023 						priv->dp_out_buf_len + 2;
1024 		memcpy(port->write_urb->transfer_buffer + 2, priv->dp_out_buf,
1025 			priv->dp_out_buf_len);
1026 		ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1027 		if (ret == 0) {
1028 			priv->dp_write_urb_in_use = 1;
1029 			priv->dp_out_buf_len = 0;
1030 		}
1031 	}
1032 	/* wake up processes sleeping on writes immediately */
1033 	tty_port_tty_wakeup(&port->port);
1034 	/* also queue up a wakeup at scheduler time, in case we */
1035 	/* lost the race in write_chan(). */
1036 	schedule_work(&priv->dp_wakeup_work);
1037 
1038 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1039 	if (ret && ret != -EPERM)
1040 		dev_err_console(port,
1041 			"%s: usb_submit_urb failed, ret=%d, port=%d\n",
1042 			__func__, ret, priv->dp_port_num);
1043 }
1044 
1045 static int digi_write_room(struct tty_struct *tty)
1046 {
1047 	struct usb_serial_port *port = tty->driver_data;
1048 	struct digi_port *priv = usb_get_serial_port_data(port);
1049 	int room;
1050 	unsigned long flags = 0;
1051 
1052 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1053 
1054 	if (priv->dp_write_urb_in_use)
1055 		room = 0;
1056 	else
1057 		room = port->bulk_out_size - 2 - priv->dp_out_buf_len;
1058 
1059 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1060 	dev_dbg(&port->dev, "digi_write_room: port=%d, room=%d\n", priv->dp_port_num, room);
1061 	return room;
1062 
1063 }
1064 
1065 static int digi_chars_in_buffer(struct tty_struct *tty)
1066 {
1067 	struct usb_serial_port *port = tty->driver_data;
1068 	struct digi_port *priv = usb_get_serial_port_data(port);
1069 
1070 	if (priv->dp_write_urb_in_use) {
1071 		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
1072 			priv->dp_port_num, port->bulk_out_size - 2);
1073 		/* return(port->bulk_out_size - 2); */
1074 		return 256;
1075 	} else {
1076 		dev_dbg(&port->dev, "digi_chars_in_buffer: port=%d, chars=%d\n",
1077 			priv->dp_port_num, priv->dp_out_buf_len);
1078 		return priv->dp_out_buf_len;
1079 	}
1080 
1081 }
1082 
1083 static void digi_dtr_rts(struct usb_serial_port *port, int on)
1084 {
1085 	/* Adjust DTR and RTS */
1086 	digi_set_modem_signals(port, on * (TIOCM_DTR | TIOCM_RTS), 1);
1087 }
1088 
1089 static int digi_open(struct tty_struct *tty, struct usb_serial_port *port)
1090 {
1091 	int ret;
1092 	unsigned char buf[32];
1093 	struct digi_port *priv = usb_get_serial_port_data(port);
1094 	struct ktermios not_termios;
1095 
1096 	/* be sure the device is started up */
1097 	if (digi_startup_device(port->serial) != 0)
1098 		return -ENXIO;
1099 
1100 	/* read modem signals automatically whenever they change */
1101 	buf[0] = DIGI_CMD_READ_INPUT_SIGNALS;
1102 	buf[1] = priv->dp_port_num;
1103 	buf[2] = DIGI_ENABLE;
1104 	buf[3] = 0;
1105 
1106 	/* flush fifos */
1107 	buf[4] = DIGI_CMD_IFLUSH_FIFO;
1108 	buf[5] = priv->dp_port_num;
1109 	buf[6] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1110 	buf[7] = 0;
1111 
1112 	ret = digi_write_oob_command(port, buf, 8, 1);
1113 	if (ret != 0)
1114 		dev_dbg(&port->dev, "digi_open: write oob failed, ret=%d\n", ret);
1115 
1116 	/* set termios settings */
1117 	if (tty) {
1118 		not_termios.c_cflag = ~tty->termios.c_cflag;
1119 		not_termios.c_iflag = ~tty->termios.c_iflag;
1120 		digi_set_termios(tty, port, &not_termios);
1121 	}
1122 	return 0;
1123 }
1124 
1125 
1126 static void digi_close(struct usb_serial_port *port)
1127 {
1128 	DEFINE_WAIT(wait);
1129 	int ret;
1130 	unsigned char buf[32];
1131 	struct digi_port *priv = usb_get_serial_port_data(port);
1132 
1133 	mutex_lock(&port->serial->disc_mutex);
1134 	/* if disconnected, just clear flags */
1135 	if (port->serial->disconnected)
1136 		goto exit;
1137 
1138 	/* FIXME: Transmit idle belongs in the wait_unti_sent path */
1139 	digi_transmit_idle(port, DIGI_CLOSE_TIMEOUT);
1140 
1141 	/* disable input flow control */
1142 	buf[0] = DIGI_CMD_SET_INPUT_FLOW_CONTROL;
1143 	buf[1] = priv->dp_port_num;
1144 	buf[2] = DIGI_DISABLE;
1145 	buf[3] = 0;
1146 
1147 	/* disable output flow control */
1148 	buf[4] = DIGI_CMD_SET_OUTPUT_FLOW_CONTROL;
1149 	buf[5] = priv->dp_port_num;
1150 	buf[6] = DIGI_DISABLE;
1151 	buf[7] = 0;
1152 
1153 	/* disable reading modem signals automatically */
1154 	buf[8] = DIGI_CMD_READ_INPUT_SIGNALS;
1155 	buf[9] = priv->dp_port_num;
1156 	buf[10] = DIGI_DISABLE;
1157 	buf[11] = 0;
1158 
1159 	/* disable receive */
1160 	buf[12] = DIGI_CMD_RECEIVE_ENABLE;
1161 	buf[13] = priv->dp_port_num;
1162 	buf[14] = DIGI_DISABLE;
1163 	buf[15] = 0;
1164 
1165 	/* flush fifos */
1166 	buf[16] = DIGI_CMD_IFLUSH_FIFO;
1167 	buf[17] = priv->dp_port_num;
1168 	buf[18] = DIGI_FLUSH_TX | DIGI_FLUSH_RX;
1169 	buf[19] = 0;
1170 
1171 	ret = digi_write_oob_command(port, buf, 20, 0);
1172 	if (ret != 0)
1173 		dev_dbg(&port->dev, "digi_close: write oob failed, ret=%d\n",
1174 									ret);
1175 	/* wait for final commands on oob port to complete */
1176 	prepare_to_wait(&priv->dp_flush_wait, &wait,
1177 			TASK_INTERRUPTIBLE);
1178 	schedule_timeout(DIGI_CLOSE_TIMEOUT);
1179 	finish_wait(&priv->dp_flush_wait, &wait);
1180 
1181 	/* shutdown any outstanding bulk writes */
1182 	usb_kill_urb(port->write_urb);
1183 exit:
1184 	spin_lock_irq(&priv->dp_port_lock);
1185 	priv->dp_write_urb_in_use = 0;
1186 	wake_up_interruptible(&priv->dp_close_wait);
1187 	spin_unlock_irq(&priv->dp_port_lock);
1188 	mutex_unlock(&port->serial->disc_mutex);
1189 }
1190 
1191 
1192 /*
1193  *  Digi Startup Device
1194  *
1195  *  Starts reads on all ports.  Must be called AFTER startup, with
1196  *  urbs initialized.  Returns 0 if successful, non-zero error otherwise.
1197  */
1198 
1199 static int digi_startup_device(struct usb_serial *serial)
1200 {
1201 	int i, ret = 0;
1202 	struct digi_serial *serial_priv = usb_get_serial_data(serial);
1203 	struct usb_serial_port *port;
1204 
1205 	/* be sure this happens exactly once */
1206 	spin_lock(&serial_priv->ds_serial_lock);
1207 	if (serial_priv->ds_device_started) {
1208 		spin_unlock(&serial_priv->ds_serial_lock);
1209 		return 0;
1210 	}
1211 	serial_priv->ds_device_started = 1;
1212 	spin_unlock(&serial_priv->ds_serial_lock);
1213 
1214 	/* start reading from each bulk in endpoint for the device */
1215 	/* set USB_DISABLE_SPD flag for write bulk urbs */
1216 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1217 		port = serial->port[i];
1218 		ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
1219 		if (ret != 0) {
1220 			dev_err(&port->dev,
1221 				"%s: usb_submit_urb failed, ret=%d, port=%d\n",
1222 				__func__, ret, i);
1223 			break;
1224 		}
1225 	}
1226 	return ret;
1227 }
1228 
1229 static int digi_port_init(struct usb_serial_port *port, unsigned port_num)
1230 {
1231 	struct digi_port *priv;
1232 
1233 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1234 	if (!priv)
1235 		return -ENOMEM;
1236 
1237 	spin_lock_init(&priv->dp_port_lock);
1238 	priv->dp_port_num = port_num;
1239 	init_waitqueue_head(&priv->dp_transmit_idle_wait);
1240 	init_waitqueue_head(&priv->dp_flush_wait);
1241 	init_waitqueue_head(&priv->dp_close_wait);
1242 	INIT_WORK(&priv->dp_wakeup_work, digi_wakeup_write_lock);
1243 	priv->dp_port = port;
1244 
1245 	init_waitqueue_head(&port->write_wait);
1246 
1247 	usb_set_serial_port_data(port, priv);
1248 
1249 	return 0;
1250 }
1251 
1252 static int digi_startup(struct usb_serial *serial)
1253 {
1254 	struct digi_serial *serial_priv;
1255 	int ret;
1256 
1257 	serial_priv = kzalloc(sizeof(*serial_priv), GFP_KERNEL);
1258 	if (!serial_priv)
1259 		return -ENOMEM;
1260 
1261 	spin_lock_init(&serial_priv->ds_serial_lock);
1262 	serial_priv->ds_oob_port_num = serial->type->num_ports;
1263 	serial_priv->ds_oob_port = serial->port[serial_priv->ds_oob_port_num];
1264 
1265 	ret = digi_port_init(serial_priv->ds_oob_port,
1266 						serial_priv->ds_oob_port_num);
1267 	if (ret) {
1268 		kfree(serial_priv);
1269 		return ret;
1270 	}
1271 
1272 	usb_set_serial_data(serial, serial_priv);
1273 
1274 	return 0;
1275 }
1276 
1277 
1278 static void digi_disconnect(struct usb_serial *serial)
1279 {
1280 	int i;
1281 
1282 	/* stop reads and writes on all ports */
1283 	for (i = 0; i < serial->type->num_ports + 1; i++) {
1284 		usb_kill_urb(serial->port[i]->read_urb);
1285 		usb_kill_urb(serial->port[i]->write_urb);
1286 	}
1287 }
1288 
1289 
1290 static void digi_release(struct usb_serial *serial)
1291 {
1292 	struct digi_serial *serial_priv;
1293 	struct digi_port *priv;
1294 
1295 	serial_priv = usb_get_serial_data(serial);
1296 
1297 	priv = usb_get_serial_port_data(serial_priv->ds_oob_port);
1298 	kfree(priv);
1299 
1300 	kfree(serial_priv);
1301 }
1302 
1303 static int digi_port_probe(struct usb_serial_port *port)
1304 {
1305 	return digi_port_init(port, port->port_number);
1306 }
1307 
1308 static int digi_port_remove(struct usb_serial_port *port)
1309 {
1310 	struct digi_port *priv;
1311 
1312 	priv = usb_get_serial_port_data(port);
1313 	kfree(priv);
1314 
1315 	return 0;
1316 }
1317 
1318 static void digi_read_bulk_callback(struct urb *urb)
1319 {
1320 	struct usb_serial_port *port = urb->context;
1321 	struct digi_port *priv;
1322 	struct digi_serial *serial_priv;
1323 	int ret;
1324 	int status = urb->status;
1325 
1326 	/* port sanity check, do not resubmit if port is not valid */
1327 	if (port == NULL)
1328 		return;
1329 	priv = usb_get_serial_port_data(port);
1330 	if (priv == NULL) {
1331 		dev_err(&port->dev, "%s: port->private is NULL, status=%d\n",
1332 			__func__, status);
1333 		return;
1334 	}
1335 	if (port->serial == NULL ||
1336 		(serial_priv = usb_get_serial_data(port->serial)) == NULL) {
1337 		dev_err(&port->dev, "%s: serial is bad or serial->private "
1338 			"is NULL, status=%d\n", __func__, status);
1339 		return;
1340 	}
1341 
1342 	/* do not resubmit urb if it has any status error */
1343 	if (status) {
1344 		dev_err(&port->dev,
1345 			"%s: nonzero read bulk status: status=%d, port=%d\n",
1346 			__func__, status, priv->dp_port_num);
1347 		return;
1348 	}
1349 
1350 	/* handle oob or inb callback, do not resubmit if error */
1351 	if (priv->dp_port_num == serial_priv->ds_oob_port_num) {
1352 		if (digi_read_oob_callback(urb) != 0)
1353 			return;
1354 	} else {
1355 		if (digi_read_inb_callback(urb) != 0)
1356 			return;
1357 	}
1358 
1359 	/* continue read */
1360 	ret = usb_submit_urb(urb, GFP_ATOMIC);
1361 	if (ret != 0 && ret != -EPERM) {
1362 		dev_err(&port->dev,
1363 			"%s: failed resubmitting urb, ret=%d, port=%d\n",
1364 			__func__, ret, priv->dp_port_num);
1365 	}
1366 
1367 }
1368 
1369 /*
1370  *  Digi Read INB Callback
1371  *
1372  *  Digi Read INB Callback handles reads on the in band ports, sending
1373  *  the data on to the tty subsystem.  When called we know port and
1374  *  port->private are not NULL and port->serial has been validated.
1375  *  It returns 0 if successful, 1 if successful but the port is
1376  *  throttled, and -1 if the sanity checks failed.
1377  */
1378 
1379 static int digi_read_inb_callback(struct urb *urb)
1380 {
1381 	struct usb_serial_port *port = urb->context;
1382 	struct digi_port *priv = usb_get_serial_port_data(port);
1383 	unsigned char *buf = urb->transfer_buffer;
1384 	unsigned long flags;
1385 	int opcode;
1386 	int len;
1387 	int port_status;
1388 	unsigned char *data;
1389 	int tty_flag, throttled;
1390 
1391 	/* short/multiple packet check */
1392 	if (urb->actual_length < 2) {
1393 		dev_warn(&port->dev, "short packet received\n");
1394 		return -1;
1395 	}
1396 
1397 	opcode = buf[0];
1398 	len = buf[1];
1399 
1400 	if (urb->actual_length != len + 2) {
1401 		dev_err(&port->dev, "malformed packet received: port=%d, opcode=%d, len=%d, actual_length=%u\n",
1402 			priv->dp_port_num, opcode, len, urb->actual_length);
1403 		return -1;
1404 	}
1405 
1406 	if (opcode == DIGI_CMD_RECEIVE_DATA && len < 1) {
1407 		dev_err(&port->dev, "malformed data packet received\n");
1408 		return -1;
1409 	}
1410 
1411 	spin_lock_irqsave(&priv->dp_port_lock, flags);
1412 
1413 	/* check for throttle; if set, do not resubmit read urb */
1414 	/* indicate the read chain needs to be restarted on unthrottle */
1415 	throttled = priv->dp_throttled;
1416 	if (throttled)
1417 		priv->dp_throttle_restart = 1;
1418 
1419 	/* receive data */
1420 	if (opcode == DIGI_CMD_RECEIVE_DATA) {
1421 		port_status = buf[2];
1422 		data = &buf[3];
1423 
1424 		/* get flag from port_status */
1425 		tty_flag = 0;
1426 
1427 		/* overrun is special, not associated with a char */
1428 		if (port_status & DIGI_OVERRUN_ERROR)
1429 			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
1430 
1431 		/* break takes precedence over parity, */
1432 		/* which takes precedence over framing errors */
1433 		if (port_status & DIGI_BREAK_ERROR)
1434 			tty_flag = TTY_BREAK;
1435 		else if (port_status & DIGI_PARITY_ERROR)
1436 			tty_flag = TTY_PARITY;
1437 		else if (port_status & DIGI_FRAMING_ERROR)
1438 			tty_flag = TTY_FRAME;
1439 
1440 		/* data length is len-1 (one byte of len is port_status) */
1441 		--len;
1442 		if (len > 0) {
1443 			tty_insert_flip_string_fixed_flag(&port->port, data,
1444 					tty_flag, len);
1445 			tty_flip_buffer_push(&port->port);
1446 		}
1447 	}
1448 	spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1449 
1450 	if (opcode == DIGI_CMD_RECEIVE_DISABLE)
1451 		dev_dbg(&port->dev, "%s: got RECEIVE_DISABLE\n", __func__);
1452 	else if (opcode != DIGI_CMD_RECEIVE_DATA)
1453 		dev_dbg(&port->dev, "%s: unknown opcode: %d\n", __func__, opcode);
1454 
1455 	return throttled ? 1 : 0;
1456 
1457 }
1458 
1459 
1460 /*
1461  *  Digi Read OOB Callback
1462  *
1463  *  Digi Read OOB Callback handles reads on the out of band port.
1464  *  When called we know port and port->private are not NULL and
1465  *  the port->serial is valid.  It returns 0 if successful, and
1466  *  -1 if the sanity checks failed.
1467  */
1468 
1469 static int digi_read_oob_callback(struct urb *urb)
1470 {
1471 
1472 	struct usb_serial_port *port = urb->context;
1473 	struct usb_serial *serial = port->serial;
1474 	struct tty_struct *tty;
1475 	struct digi_port *priv;
1476 	unsigned char *buf = urb->transfer_buffer;
1477 	int opcode, line, status, val;
1478 	unsigned long flags;
1479 	int i;
1480 	unsigned int rts;
1481 
1482 	if (urb->actual_length < 4)
1483 		return -1;
1484 
1485 	/* handle each oob command */
1486 	for (i = 0; i < urb->actual_length - 3; i += 4) {
1487 		opcode = buf[i];
1488 		line = buf[i + 1];
1489 		status = buf[i + 2];
1490 		val = buf[i + 3];
1491 
1492 		dev_dbg(&port->dev, "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d\n",
1493 			opcode, line, status, val);
1494 
1495 		if (status != 0 || line >= serial->type->num_ports)
1496 			continue;
1497 
1498 		port = serial->port[line];
1499 
1500 		priv = usb_get_serial_port_data(port);
1501 		if (priv == NULL)
1502 			return -1;
1503 
1504 		tty = tty_port_tty_get(&port->port);
1505 
1506 		rts = 0;
1507 		if (tty)
1508 			rts = C_CRTSCTS(tty);
1509 
1510 		if (tty && opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
1511 			spin_lock_irqsave(&priv->dp_port_lock, flags);
1512 			/* convert from digi flags to termiox flags */
1513 			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
1514 				priv->dp_modem_signals |= TIOCM_CTS;
1515 				/* port must be open to use tty struct */
1516 				if (rts)
1517 					tty_port_tty_wakeup(&port->port);
1518 			} else {
1519 				priv->dp_modem_signals &= ~TIOCM_CTS;
1520 				/* port must be open to use tty struct */
1521 			}
1522 			if (val & DIGI_READ_INPUT_SIGNALS_DSR)
1523 				priv->dp_modem_signals |= TIOCM_DSR;
1524 			else
1525 				priv->dp_modem_signals &= ~TIOCM_DSR;
1526 			if (val & DIGI_READ_INPUT_SIGNALS_RI)
1527 				priv->dp_modem_signals |= TIOCM_RI;
1528 			else
1529 				priv->dp_modem_signals &= ~TIOCM_RI;
1530 			if (val & DIGI_READ_INPUT_SIGNALS_DCD)
1531 				priv->dp_modem_signals |= TIOCM_CD;
1532 			else
1533 				priv->dp_modem_signals &= ~TIOCM_CD;
1534 
1535 			spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1536 		} else if (opcode == DIGI_CMD_TRANSMIT_IDLE) {
1537 			spin_lock_irqsave(&priv->dp_port_lock, flags);
1538 			priv->dp_transmit_idle = 1;
1539 			wake_up_interruptible(&priv->dp_transmit_idle_wait);
1540 			spin_unlock_irqrestore(&priv->dp_port_lock, flags);
1541 		} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
1542 			wake_up_interruptible(&priv->dp_flush_wait);
1543 		}
1544 		tty_kref_put(tty);
1545 	}
1546 	return 0;
1547 
1548 }
1549 
1550 module_usb_serial_driver(serial_drivers, id_table_combined);
1551 
1552 MODULE_AUTHOR(DRIVER_AUTHOR);
1553 MODULE_DESCRIPTION(DRIVER_DESC);
1554 MODULE_LICENSE("GPL");
1555