1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * MCT (Magic Control Technology Corp.) USB RS232 Converter Driver
4 *
5 * Copyright (C) 2000 Wolfgang Grandegger (wolfgang@ces.ch)
6 *
7 * This program is largely derived from the Belkin USB Serial Adapter Driver
8 * (see belkin_sa.[ch]). All of the information about the device was acquired
9 * by using SniffUSB on Windows98. For technical details see mct_u232.h.
10 *
11 * William G. Greathouse and Greg Kroah-Hartman provided great help on how to
12 * do the reverse engineering and how to write a USB serial device driver.
13 *
14 * TO BE DONE, TO BE CHECKED:
15 * DTR/RTS signal handling may be incomplete or incorrect. I have mainly
16 * implemented what I have seen with SniffUSB or found in belkin_sa.c.
17 * For further TODOs check also belkin_sa.c.
18 */
19
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/slab.h>
23 #include <linux/tty.h>
24 #include <linux/tty_driver.h>
25 #include <linux/tty_flip.h>
26 #include <linux/module.h>
27 #include <linux/spinlock.h>
28 #include <linux/uaccess.h>
29 #include <linux/unaligned.h>
30 #include <linux/usb.h>
31 #include <linux/usb/serial.h>
32 #include <linux/serial.h>
33 #include "mct_u232.h"
34
35 #define DRIVER_AUTHOR "Wolfgang Grandegger <wolfgang@ces.ch>"
36 #define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"
37
38 /*
39 * Function prototypes
40 */
41 static int mct_u232_port_probe(struct usb_serial_port *port);
42 static void mct_u232_port_remove(struct usb_serial_port *remove);
43 static int mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port);
44 static void mct_u232_close(struct usb_serial_port *port);
45 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on);
46 static void mct_u232_read_int_callback(struct urb *urb);
47 static void mct_u232_set_termios(struct tty_struct *tty,
48 struct usb_serial_port *port,
49 const struct ktermios *old_termios);
50 static int mct_u232_break_ctl(struct tty_struct *tty, int break_state);
51 static int mct_u232_tiocmget(struct tty_struct *tty);
52 static int mct_u232_tiocmset(struct tty_struct *tty,
53 unsigned int set, unsigned int clear);
54 static void mct_u232_throttle(struct tty_struct *tty);
55 static void mct_u232_unthrottle(struct tty_struct *tty);
56
57
58 /*
59 * All of the device info needed for the MCT USB-RS232 converter.
60 */
61 static const struct usb_device_id id_table[] = {
62 { USB_DEVICE(MCT_U232_VID, MCT_U232_PID) },
63 { USB_DEVICE(MCT_U232_VID, MCT_U232_SITECOM_PID) },
64 { USB_DEVICE(MCT_U232_VID, MCT_U232_DU_H3SP_PID) },
65 { USB_DEVICE(MCT_U232_BELKIN_F5U109_VID, MCT_U232_BELKIN_F5U109_PID) },
66 { } /* Terminating entry */
67 };
68 MODULE_DEVICE_TABLE(usb, id_table);
69
70 static struct usb_serial_driver mct_u232_device = {
71 .driver = {
72 .name = "mct_u232",
73 },
74 .description = "MCT U232",
75 .id_table = id_table,
76 .num_ports = 1,
77 .open = mct_u232_open,
78 .close = mct_u232_close,
79 .dtr_rts = mct_u232_dtr_rts,
80 .throttle = mct_u232_throttle,
81 .unthrottle = mct_u232_unthrottle,
82 .read_int_callback = mct_u232_read_int_callback,
83 .set_termios = mct_u232_set_termios,
84 .break_ctl = mct_u232_break_ctl,
85 .tiocmget = mct_u232_tiocmget,
86 .tiocmset = mct_u232_tiocmset,
87 .tiocmiwait = usb_serial_generic_tiocmiwait,
88 .port_probe = mct_u232_port_probe,
89 .port_remove = mct_u232_port_remove,
90 .get_icount = usb_serial_generic_get_icount,
91 };
92
93 static struct usb_serial_driver * const serial_drivers[] = {
94 &mct_u232_device, NULL
95 };
96
97 struct mct_u232_private {
98 struct urb *read_urb;
99 spinlock_t lock;
100 unsigned int control_state; /* Modem Line Setting (TIOCM) */
101 unsigned char last_lcr; /* Line Control Register */
102 unsigned char last_lsr; /* Line Status Register */
103 unsigned char last_msr; /* Modem Status Register */
104 unsigned int rx_flags; /* Throttling flags */
105 };
106
107 #define THROTTLED 0x01
108
109 /*
110 * Handle vendor specific USB requests
111 */
112
113 #define WDR_TIMEOUT 5000 /* default urb timeout */
114
115 /*
116 * Later day 2.6.0-test kernels have new baud rates like B230400 which
117 * we do not know how to support. We ignore them for the moment.
118 */
mct_u232_calculate_baud_rate(struct usb_serial * serial,speed_t value,speed_t * result)119 static int mct_u232_calculate_baud_rate(struct usb_serial *serial,
120 speed_t value, speed_t *result)
121 {
122 *result = value;
123
124 if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID
125 || le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_BELKIN_F5U109_PID) {
126 switch (value) {
127 case 300:
128 return 0x01;
129 case 600:
130 return 0x02; /* this one not tested */
131 case 1200:
132 return 0x03;
133 case 2400:
134 return 0x04;
135 case 4800:
136 return 0x06;
137 case 9600:
138 return 0x08;
139 case 19200:
140 return 0x09;
141 case 38400:
142 return 0x0a;
143 case 57600:
144 return 0x0b;
145 case 115200:
146 return 0x0c;
147 default:
148 *result = 9600;
149 return 0x08;
150 }
151 } else {
152 /* FIXME: Can we use any divider - should we do
153 divider = 115200/value;
154 real baud = 115200/divider */
155 switch (value) {
156 case 300: break;
157 case 600: break;
158 case 1200: break;
159 case 2400: break;
160 case 4800: break;
161 case 9600: break;
162 case 19200: break;
163 case 38400: break;
164 case 57600: break;
165 case 115200: break;
166 default:
167 value = 9600;
168 *result = 9600;
169 }
170 return 115200/value;
171 }
172 }
173
mct_u232_set_baud_rate(struct tty_struct * tty,struct usb_serial * serial,struct usb_serial_port * port,speed_t value)174 static int mct_u232_set_baud_rate(struct tty_struct *tty,
175 struct usb_serial *serial, struct usb_serial_port *port, speed_t value)
176 {
177 unsigned int divisor;
178 int rc;
179 unsigned char *buf;
180 unsigned char cts_enable_byte = 0;
181 speed_t speed;
182
183 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
184 if (buf == NULL)
185 return -ENOMEM;
186
187 divisor = mct_u232_calculate_baud_rate(serial, value, &speed);
188 put_unaligned_le32(divisor, buf);
189 rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
190 MCT_U232_SET_BAUD_RATE_REQUEST,
191 MCT_U232_SET_REQUEST_TYPE,
192 0, 0, buf, MCT_U232_SET_BAUD_RATE_SIZE,
193 WDR_TIMEOUT);
194 if (rc < 0) /*FIXME: What value speed results */
195 dev_err(&port->dev, "Set BAUD RATE %d failed (error = %d)\n",
196 value, rc);
197 else
198 tty_encode_baud_rate(tty, speed, speed);
199 dev_dbg(&port->dev, "set_baud_rate: value: 0x%x, divisor: 0x%x\n", value, divisor);
200
201 /* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
202 always sends two extra USB 'device request' messages after the
203 'baud rate change' message. The actual functionality of the
204 request codes in these messages is not fully understood but these
205 particular codes are never seen in any operation besides a baud
206 rate change. Both of these messages send a single byte of data.
207 In the first message, the value of this byte is always zero.
208
209 The second message has been determined experimentally to control
210 whether data will be transmitted to a device which is not asserting
211 the 'CTS' signal. If the second message's data byte is zero, data
212 will be transmitted even if 'CTS' is not asserted (i.e. no hardware
213 flow control). if the second message's data byte is nonzero (a
214 value of 1 is used by this driver), data will not be transmitted to
215 a device which is not asserting 'CTS'.
216 */
217
218 buf[0] = 0;
219 rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
220 MCT_U232_SET_UNKNOWN1_REQUEST,
221 MCT_U232_SET_REQUEST_TYPE,
222 0, 0, buf, MCT_U232_SET_UNKNOWN1_SIZE,
223 WDR_TIMEOUT);
224 if (rc < 0)
225 dev_err(&port->dev, "Sending USB device request code %d "
226 "failed (error = %d)\n", MCT_U232_SET_UNKNOWN1_REQUEST,
227 rc);
228
229 if (port && C_CRTSCTS(tty))
230 cts_enable_byte = 1;
231
232 dev_dbg(&port->dev, "set_baud_rate: send second control message, data = %02X\n",
233 cts_enable_byte);
234 buf[0] = cts_enable_byte;
235 rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
236 MCT_U232_SET_CTS_REQUEST,
237 MCT_U232_SET_REQUEST_TYPE,
238 0, 0, buf, MCT_U232_SET_CTS_SIZE,
239 WDR_TIMEOUT);
240 if (rc < 0)
241 dev_err(&port->dev, "Sending USB device request code %d "
242 "failed (error = %d)\n", MCT_U232_SET_CTS_REQUEST, rc);
243
244 kfree(buf);
245 return rc;
246 } /* mct_u232_set_baud_rate */
247
mct_u232_set_line_ctrl(struct usb_serial_port * port,unsigned char lcr)248 static int mct_u232_set_line_ctrl(struct usb_serial_port *port,
249 unsigned char lcr)
250 {
251 int rc;
252 unsigned char *buf;
253
254 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
255 if (buf == NULL)
256 return -ENOMEM;
257
258 buf[0] = lcr;
259 rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
260 MCT_U232_SET_LINE_CTRL_REQUEST,
261 MCT_U232_SET_REQUEST_TYPE,
262 0, 0, buf, MCT_U232_SET_LINE_CTRL_SIZE,
263 WDR_TIMEOUT);
264 if (rc < 0)
265 dev_err(&port->dev, "Set LINE CTRL 0x%x failed (error = %d)\n", lcr, rc);
266 dev_dbg(&port->dev, "set_line_ctrl: 0x%x\n", lcr);
267 kfree(buf);
268 return rc;
269 } /* mct_u232_set_line_ctrl */
270
mct_u232_set_modem_ctrl(struct usb_serial_port * port,unsigned int control_state)271 static int mct_u232_set_modem_ctrl(struct usb_serial_port *port,
272 unsigned int control_state)
273 {
274 int rc;
275 unsigned char mcr;
276 unsigned char *buf;
277
278 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
279 if (buf == NULL)
280 return -ENOMEM;
281
282 mcr = MCT_U232_MCR_NONE;
283 if (control_state & TIOCM_DTR)
284 mcr |= MCT_U232_MCR_DTR;
285 if (control_state & TIOCM_RTS)
286 mcr |= MCT_U232_MCR_RTS;
287
288 buf[0] = mcr;
289 rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
290 MCT_U232_SET_MODEM_CTRL_REQUEST,
291 MCT_U232_SET_REQUEST_TYPE,
292 0, 0, buf, MCT_U232_SET_MODEM_CTRL_SIZE,
293 WDR_TIMEOUT);
294 kfree(buf);
295
296 dev_dbg(&port->dev, "set_modem_ctrl: state=0x%x ==> mcr=0x%x\n", control_state, mcr);
297
298 if (rc < 0) {
299 dev_err(&port->dev, "Set MODEM CTRL 0x%x failed (error = %d)\n", mcr, rc);
300 return rc;
301 }
302 return 0;
303 } /* mct_u232_set_modem_ctrl */
304
mct_u232_get_modem_stat(struct usb_serial_port * port,unsigned char * msr)305 static int mct_u232_get_modem_stat(struct usb_serial_port *port,
306 unsigned char *msr)
307 {
308 int rc;
309 unsigned char *buf;
310
311 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
312 if (buf == NULL) {
313 *msr = 0;
314 return -ENOMEM;
315 }
316 rc = usb_control_msg(port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
317 MCT_U232_GET_MODEM_STAT_REQUEST,
318 MCT_U232_GET_REQUEST_TYPE,
319 0, 0, buf, MCT_U232_GET_MODEM_STAT_SIZE,
320 WDR_TIMEOUT);
321 if (rc < MCT_U232_GET_MODEM_STAT_SIZE) {
322 dev_err(&port->dev, "Get MODEM STATus failed (error = %d)\n", rc);
323
324 if (rc >= 0)
325 rc = -EIO;
326
327 *msr = 0;
328 } else {
329 *msr = buf[0];
330 }
331 dev_dbg(&port->dev, "get_modem_stat: 0x%x\n", *msr);
332 kfree(buf);
333 return rc;
334 } /* mct_u232_get_modem_stat */
335
mct_u232_msr_to_icount(struct async_icount * icount,unsigned char msr)336 static void mct_u232_msr_to_icount(struct async_icount *icount,
337 unsigned char msr)
338 {
339 /* Translate Control Line states */
340 if (msr & MCT_U232_MSR_DDSR)
341 icount->dsr++;
342 if (msr & MCT_U232_MSR_DCTS)
343 icount->cts++;
344 if (msr & MCT_U232_MSR_DRI)
345 icount->rng++;
346 if (msr & MCT_U232_MSR_DCD)
347 icount->dcd++;
348 } /* mct_u232_msr_to_icount */
349
mct_u232_msr_to_state(struct usb_serial_port * port,unsigned int * control_state,unsigned char msr)350 static void mct_u232_msr_to_state(struct usb_serial_port *port,
351 unsigned int *control_state, unsigned char msr)
352 {
353 /* Translate Control Line states */
354 if (msr & MCT_U232_MSR_DSR)
355 *control_state |= TIOCM_DSR;
356 else
357 *control_state &= ~TIOCM_DSR;
358 if (msr & MCT_U232_MSR_CTS)
359 *control_state |= TIOCM_CTS;
360 else
361 *control_state &= ~TIOCM_CTS;
362 if (msr & MCT_U232_MSR_RI)
363 *control_state |= TIOCM_RI;
364 else
365 *control_state &= ~TIOCM_RI;
366 if (msr & MCT_U232_MSR_CD)
367 *control_state |= TIOCM_CD;
368 else
369 *control_state &= ~TIOCM_CD;
370 dev_dbg(&port->dev, "msr_to_state: msr=0x%x ==> state=0x%x\n", msr, *control_state);
371 } /* mct_u232_msr_to_state */
372
373 /*
374 * Driver's tty interface functions
375 */
376
mct_u232_port_probe(struct usb_serial_port * port)377 static int mct_u232_port_probe(struct usb_serial_port *port)
378 {
379 struct usb_serial *serial = port->serial;
380 struct mct_u232_private *priv;
381
382 /* check first to simplify error handling */
383 if (!serial->port[1] || !serial->port[1]->interrupt_in_urb) {
384 dev_err(&port->dev, "expected endpoint missing\n");
385 return -ENODEV;
386 }
387
388 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
389 if (!priv)
390 return -ENOMEM;
391
392 /* Use second interrupt-in endpoint for reading. */
393 priv->read_urb = serial->port[1]->interrupt_in_urb;
394 priv->read_urb->context = port;
395
396 spin_lock_init(&priv->lock);
397
398 usb_set_serial_port_data(port, priv);
399
400 return 0;
401 }
402
mct_u232_port_remove(struct usb_serial_port * port)403 static void mct_u232_port_remove(struct usb_serial_port *port)
404 {
405 struct mct_u232_private *priv;
406
407 priv = usb_get_serial_port_data(port);
408 kfree(priv);
409 }
410
mct_u232_open(struct tty_struct * tty,struct usb_serial_port * port)411 static int mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port)
412 {
413 struct usb_serial *serial = port->serial;
414 struct mct_u232_private *priv = usb_get_serial_port_data(port);
415 int retval = 0;
416 unsigned int control_state;
417 unsigned long flags;
418 unsigned char last_lcr;
419 unsigned char last_msr;
420
421 /* Compensate for a hardware bug: although the Sitecom U232-P25
422 * device reports a maximum output packet size of 32 bytes,
423 * it seems to be able to accept only 16 bytes (and that's what
424 * SniffUSB says too...)
425 */
426 if (le16_to_cpu(serial->dev->descriptor.idProduct)
427 == MCT_U232_SITECOM_PID)
428 port->bulk_out_size = 16;
429
430 /* Do a defined restart: the normal serial device seems to
431 * always turn on DTR and RTS here, so do the same. I'm not
432 * sure if this is really necessary. But it should not harm
433 * either.
434 */
435 spin_lock_irqsave(&priv->lock, flags);
436 if (tty && C_BAUD(tty))
437 priv->control_state = TIOCM_DTR | TIOCM_RTS;
438 else
439 priv->control_state = 0;
440
441 priv->last_lcr = (MCT_U232_DATA_BITS_8 |
442 MCT_U232_PARITY_NONE |
443 MCT_U232_STOP_BITS_1);
444 control_state = priv->control_state;
445 last_lcr = priv->last_lcr;
446 spin_unlock_irqrestore(&priv->lock, flags);
447 mct_u232_set_modem_ctrl(port, control_state);
448 mct_u232_set_line_ctrl(port, last_lcr);
449
450 /* Read modem status and update control state */
451 mct_u232_get_modem_stat(port, &last_msr);
452 spin_lock_irqsave(&priv->lock, flags);
453 priv->last_msr = last_msr;
454 mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
455 spin_unlock_irqrestore(&priv->lock, flags);
456
457 retval = usb_submit_urb(priv->read_urb, GFP_KERNEL);
458 if (retval) {
459 dev_err(&port->dev,
460 "usb_submit_urb(read) failed pipe 0x%x err %d\n",
461 port->read_urb->pipe, retval);
462 goto error;
463 }
464
465 retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
466 if (retval) {
467 usb_kill_urb(priv->read_urb);
468 dev_err(&port->dev,
469 "usb_submit_urb(read int) failed pipe 0x%x err %d",
470 port->interrupt_in_urb->pipe, retval);
471 goto error;
472 }
473 return 0;
474
475 error:
476 return retval;
477 } /* mct_u232_open */
478
mct_u232_dtr_rts(struct usb_serial_port * port,int on)479 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on)
480 {
481 unsigned int control_state;
482 struct mct_u232_private *priv = usb_get_serial_port_data(port);
483
484 spin_lock_irq(&priv->lock);
485 if (on)
486 priv->control_state |= TIOCM_DTR | TIOCM_RTS;
487 else
488 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
489 control_state = priv->control_state;
490 spin_unlock_irq(&priv->lock);
491
492 mct_u232_set_modem_ctrl(port, control_state);
493 }
494
mct_u232_close(struct usb_serial_port * port)495 static void mct_u232_close(struct usb_serial_port *port)
496 {
497 struct mct_u232_private *priv = usb_get_serial_port_data(port);
498
499 usb_kill_urb(priv->read_urb);
500 usb_kill_urb(port->interrupt_in_urb);
501
502 usb_serial_generic_close(port);
503 } /* mct_u232_close */
504
505
mct_u232_read_int_callback(struct urb * urb)506 static void mct_u232_read_int_callback(struct urb *urb)
507 {
508 struct usb_serial_port *port = urb->context;
509 struct mct_u232_private *priv = usb_get_serial_port_data(port);
510 unsigned char *data = urb->transfer_buffer;
511 int retval;
512 int status = urb->status;
513 unsigned long flags;
514
515 switch (status) {
516 case 0:
517 /* success */
518 break;
519 case -ECONNRESET:
520 case -ENOENT:
521 case -ESHUTDOWN:
522 /* this urb is terminated, clean up */
523 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
524 __func__, status);
525 return;
526 default:
527 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
528 __func__, status);
529 goto exit;
530 }
531
532 usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
533
534 /*
535 * Work-a-round: handle the 'usual' bulk-in pipe here
536 */
537 if (urb->transfer_buffer_length > 2) {
538 if (urb->actual_length) {
539 tty_insert_flip_string(&port->port, data,
540 urb->actual_length);
541 tty_flip_buffer_push(&port->port);
542 }
543 goto exit;
544 }
545
546 /*
547 * The interrupt-in pipe signals exceptional conditions (modem line
548 * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
549 */
550 spin_lock_irqsave(&priv->lock, flags);
551 priv->last_msr = data[MCT_U232_MSR_INDEX];
552
553 /* Record Control Line states */
554 mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
555
556 mct_u232_msr_to_icount(&port->icount, priv->last_msr);
557
558 #if 0
559 /* Not yet handled. See belkin_sa.c for further information */
560 /* Now to report any errors */
561 priv->last_lsr = data[MCT_U232_LSR_INDEX];
562 /*
563 * fill in the flip buffer here, but I do not know the relation
564 * to the current/next receive buffer or characters. I need
565 * to look in to this before committing any code.
566 */
567 if (priv->last_lsr & MCT_U232_LSR_ERR) {
568 tty = tty_port_tty_get(&port->port);
569 /* Overrun Error */
570 if (priv->last_lsr & MCT_U232_LSR_OE) {
571 }
572 /* Parity Error */
573 if (priv->last_lsr & MCT_U232_LSR_PE) {
574 }
575 /* Framing Error */
576 if (priv->last_lsr & MCT_U232_LSR_FE) {
577 }
578 /* Break Indicator */
579 if (priv->last_lsr & MCT_U232_LSR_BI) {
580 }
581 tty_kref_put(tty);
582 }
583 #endif
584 wake_up_interruptible(&port->port.delta_msr_wait);
585 spin_unlock_irqrestore(&priv->lock, flags);
586 exit:
587 retval = usb_submit_urb(urb, GFP_ATOMIC);
588 if (retval)
589 dev_err(&port->dev,
590 "%s - usb_submit_urb failed with result %d\n",
591 __func__, retval);
592 } /* mct_u232_read_int_callback */
593
mct_u232_set_termios(struct tty_struct * tty,struct usb_serial_port * port,const struct ktermios * old_termios)594 static void mct_u232_set_termios(struct tty_struct *tty,
595 struct usb_serial_port *port,
596 const struct ktermios *old_termios)
597 {
598 struct usb_serial *serial = port->serial;
599 struct mct_u232_private *priv = usb_get_serial_port_data(port);
600 struct ktermios *termios = &tty->termios;
601 unsigned int cflag = termios->c_cflag;
602 unsigned int old_cflag = old_termios->c_cflag;
603 unsigned long flags;
604 unsigned int control_state;
605 unsigned char last_lcr;
606
607 /* get a local copy of the current port settings */
608 spin_lock_irqsave(&priv->lock, flags);
609 control_state = priv->control_state;
610 spin_unlock_irqrestore(&priv->lock, flags);
611 last_lcr = 0;
612
613 /*
614 * Update baud rate.
615 * Do not attempt to cache old rates and skip settings,
616 * disconnects screw such tricks up completely.
617 * Premature optimization is the root of all evil.
618 */
619
620 /* reassert DTR and RTS on transition from B0 */
621 if ((old_cflag & CBAUD) == B0) {
622 dev_dbg(&port->dev, "%s: baud was B0\n", __func__);
623 control_state |= TIOCM_DTR | TIOCM_RTS;
624 mct_u232_set_modem_ctrl(port, control_state);
625 }
626
627 mct_u232_set_baud_rate(tty, serial, port, tty_get_baud_rate(tty));
628
629 if ((cflag & CBAUD) == B0) {
630 dev_dbg(&port->dev, "%s: baud is B0\n", __func__);
631 /* Drop RTS and DTR */
632 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
633 mct_u232_set_modem_ctrl(port, control_state);
634 }
635
636 /*
637 * Update line control register (LCR)
638 */
639
640 /* set the parity */
641 if (cflag & PARENB)
642 last_lcr |= (cflag & PARODD) ?
643 MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
644 else
645 last_lcr |= MCT_U232_PARITY_NONE;
646
647 /* set the number of data bits */
648 switch (cflag & CSIZE) {
649 case CS5:
650 last_lcr |= MCT_U232_DATA_BITS_5; break;
651 case CS6:
652 last_lcr |= MCT_U232_DATA_BITS_6; break;
653 case CS7:
654 last_lcr |= MCT_U232_DATA_BITS_7; break;
655 case CS8:
656 last_lcr |= MCT_U232_DATA_BITS_8; break;
657 default:
658 dev_err(&port->dev,
659 "CSIZE was not CS5-CS8, using default of 8\n");
660 last_lcr |= MCT_U232_DATA_BITS_8;
661 break;
662 }
663
664 termios->c_cflag &= ~CMSPAR;
665
666 /* set the number of stop bits */
667 last_lcr |= (cflag & CSTOPB) ?
668 MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
669
670 mct_u232_set_line_ctrl(port, last_lcr);
671
672 /* save off the modified port settings */
673 spin_lock_irqsave(&priv->lock, flags);
674 priv->control_state = control_state;
675 priv->last_lcr = last_lcr;
676 spin_unlock_irqrestore(&priv->lock, flags);
677 } /* mct_u232_set_termios */
678
mct_u232_break_ctl(struct tty_struct * tty,int break_state)679 static int mct_u232_break_ctl(struct tty_struct *tty, int break_state)
680 {
681 struct usb_serial_port *port = tty->driver_data;
682 struct mct_u232_private *priv = usb_get_serial_port_data(port);
683 unsigned char lcr;
684 unsigned long flags;
685
686 spin_lock_irqsave(&priv->lock, flags);
687 lcr = priv->last_lcr;
688
689 if (break_state)
690 lcr |= MCT_U232_SET_BREAK;
691 spin_unlock_irqrestore(&priv->lock, flags);
692
693 return mct_u232_set_line_ctrl(port, lcr);
694 } /* mct_u232_break_ctl */
695
696
mct_u232_tiocmget(struct tty_struct * tty)697 static int mct_u232_tiocmget(struct tty_struct *tty)
698 {
699 struct usb_serial_port *port = tty->driver_data;
700 struct mct_u232_private *priv = usb_get_serial_port_data(port);
701 unsigned int control_state;
702 unsigned long flags;
703
704 spin_lock_irqsave(&priv->lock, flags);
705 control_state = priv->control_state;
706 spin_unlock_irqrestore(&priv->lock, flags);
707
708 return control_state;
709 }
710
mct_u232_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)711 static int mct_u232_tiocmset(struct tty_struct *tty,
712 unsigned int set, unsigned int clear)
713 {
714 struct usb_serial_port *port = tty->driver_data;
715 struct mct_u232_private *priv = usb_get_serial_port_data(port);
716 unsigned int control_state;
717 unsigned long flags;
718
719 spin_lock_irqsave(&priv->lock, flags);
720 control_state = priv->control_state;
721
722 if (set & TIOCM_RTS)
723 control_state |= TIOCM_RTS;
724 if (set & TIOCM_DTR)
725 control_state |= TIOCM_DTR;
726 if (clear & TIOCM_RTS)
727 control_state &= ~TIOCM_RTS;
728 if (clear & TIOCM_DTR)
729 control_state &= ~TIOCM_DTR;
730
731 priv->control_state = control_state;
732 spin_unlock_irqrestore(&priv->lock, flags);
733 return mct_u232_set_modem_ctrl(port, control_state);
734 }
735
mct_u232_throttle(struct tty_struct * tty)736 static void mct_u232_throttle(struct tty_struct *tty)
737 {
738 struct usb_serial_port *port = tty->driver_data;
739 struct mct_u232_private *priv = usb_get_serial_port_data(port);
740 unsigned int control_state;
741
742 spin_lock_irq(&priv->lock);
743 priv->rx_flags |= THROTTLED;
744 if (C_CRTSCTS(tty)) {
745 priv->control_state &= ~TIOCM_RTS;
746 control_state = priv->control_state;
747 spin_unlock_irq(&priv->lock);
748 mct_u232_set_modem_ctrl(port, control_state);
749 } else {
750 spin_unlock_irq(&priv->lock);
751 }
752 }
753
mct_u232_unthrottle(struct tty_struct * tty)754 static void mct_u232_unthrottle(struct tty_struct *tty)
755 {
756 struct usb_serial_port *port = tty->driver_data;
757 struct mct_u232_private *priv = usb_get_serial_port_data(port);
758 unsigned int control_state;
759
760 spin_lock_irq(&priv->lock);
761 if ((priv->rx_flags & THROTTLED) && C_CRTSCTS(tty)) {
762 priv->rx_flags &= ~THROTTLED;
763 priv->control_state |= TIOCM_RTS;
764 control_state = priv->control_state;
765 spin_unlock_irq(&priv->lock);
766 mct_u232_set_modem_ctrl(port, control_state);
767 } else {
768 spin_unlock_irq(&priv->lock);
769 }
770 }
771
772 module_usb_serial_driver(serial_drivers, id_table);
773
774 MODULE_AUTHOR(DRIVER_AUTHOR);
775 MODULE_DESCRIPTION(DRIVER_DESC);
776 MODULE_LICENSE("GPL");
777