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 <asm/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 .owner = THIS_MODULE,
73 .name = "mct_u232",
74 },
75 .description = "MCT U232",
76 .id_table = id_table,
77 .num_ports = 1,
78 .open = mct_u232_open,
79 .close = mct_u232_close,
80 .dtr_rts = mct_u232_dtr_rts,
81 .throttle = mct_u232_throttle,
82 .unthrottle = mct_u232_unthrottle,
83 .read_int_callback = mct_u232_read_int_callback,
84 .set_termios = mct_u232_set_termios,
85 .break_ctl = mct_u232_break_ctl,
86 .tiocmget = mct_u232_tiocmget,
87 .tiocmset = mct_u232_tiocmset,
88 .tiocmiwait = usb_serial_generic_tiocmiwait,
89 .port_probe = mct_u232_port_probe,
90 .port_remove = mct_u232_port_remove,
91 .get_icount = usb_serial_generic_get_icount,
92 };
93
94 static struct usb_serial_driver * const serial_drivers[] = {
95 &mct_u232_device, NULL
96 };
97
98 struct mct_u232_private {
99 struct urb *read_urb;
100 spinlock_t lock;
101 unsigned int control_state; /* Modem Line Setting (TIOCM) */
102 unsigned char last_lcr; /* Line Control Register */
103 unsigned char last_lsr; /* Line Status Register */
104 unsigned char last_msr; /* Modem Status Register */
105 unsigned int rx_flags; /* Throttling flags */
106 };
107
108 #define THROTTLED 0x01
109
110 /*
111 * Handle vendor specific USB requests
112 */
113
114 #define WDR_TIMEOUT 5000 /* default urb timeout */
115
116 /*
117 * Later day 2.6.0-test kernels have new baud rates like B230400 which
118 * we do not know how to support. We ignore them for the moment.
119 */
mct_u232_calculate_baud_rate(struct usb_serial * serial,speed_t value,speed_t * result)120 static int mct_u232_calculate_baud_rate(struct usb_serial *serial,
121 speed_t value, speed_t *result)
122 {
123 *result = value;
124
125 if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID
126 || le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_BELKIN_F5U109_PID) {
127 switch (value) {
128 case 300:
129 return 0x01;
130 case 600:
131 return 0x02; /* this one not tested */
132 case 1200:
133 return 0x03;
134 case 2400:
135 return 0x04;
136 case 4800:
137 return 0x06;
138 case 9600:
139 return 0x08;
140 case 19200:
141 return 0x09;
142 case 38400:
143 return 0x0a;
144 case 57600:
145 return 0x0b;
146 case 115200:
147 return 0x0c;
148 default:
149 *result = 9600;
150 return 0x08;
151 }
152 } else {
153 /* FIXME: Can we use any divider - should we do
154 divider = 115200/value;
155 real baud = 115200/divider */
156 switch (value) {
157 case 300: break;
158 case 600: break;
159 case 1200: break;
160 case 2400: break;
161 case 4800: break;
162 case 9600: break;
163 case 19200: break;
164 case 38400: break;
165 case 57600: break;
166 case 115200: break;
167 default:
168 value = 9600;
169 *result = 9600;
170 }
171 return 115200/value;
172 }
173 }
174
mct_u232_set_baud_rate(struct tty_struct * tty,struct usb_serial * serial,struct usb_serial_port * port,speed_t value)175 static int mct_u232_set_baud_rate(struct tty_struct *tty,
176 struct usb_serial *serial, struct usb_serial_port *port, speed_t value)
177 {
178 unsigned int divisor;
179 int rc;
180 unsigned char *buf;
181 unsigned char cts_enable_byte = 0;
182 speed_t speed;
183
184 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
185 if (buf == NULL)
186 return -ENOMEM;
187
188 divisor = mct_u232_calculate_baud_rate(serial, value, &speed);
189 put_unaligned_le32(divisor, buf);
190 rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
191 MCT_U232_SET_BAUD_RATE_REQUEST,
192 MCT_U232_SET_REQUEST_TYPE,
193 0, 0, buf, MCT_U232_SET_BAUD_RATE_SIZE,
194 WDR_TIMEOUT);
195 if (rc < 0) /*FIXME: What value speed results */
196 dev_err(&port->dev, "Set BAUD RATE %d failed (error = %d)\n",
197 value, rc);
198 else
199 tty_encode_baud_rate(tty, speed, speed);
200 dev_dbg(&port->dev, "set_baud_rate: value: 0x%x, divisor: 0x%x\n", value, divisor);
201
202 /* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
203 always sends two extra USB 'device request' messages after the
204 'baud rate change' message. The actual functionality of the
205 request codes in these messages is not fully understood but these
206 particular codes are never seen in any operation besides a baud
207 rate change. Both of these messages send a single byte of data.
208 In the first message, the value of this byte is always zero.
209
210 The second message has been determined experimentally to control
211 whether data will be transmitted to a device which is not asserting
212 the 'CTS' signal. If the second message's data byte is zero, data
213 will be transmitted even if 'CTS' is not asserted (i.e. no hardware
214 flow control). if the second message's data byte is nonzero (a
215 value of 1 is used by this driver), data will not be transmitted to
216 a device which is not asserting 'CTS'.
217 */
218
219 buf[0] = 0;
220 rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
221 MCT_U232_SET_UNKNOWN1_REQUEST,
222 MCT_U232_SET_REQUEST_TYPE,
223 0, 0, buf, MCT_U232_SET_UNKNOWN1_SIZE,
224 WDR_TIMEOUT);
225 if (rc < 0)
226 dev_err(&port->dev, "Sending USB device request code %d "
227 "failed (error = %d)\n", MCT_U232_SET_UNKNOWN1_REQUEST,
228 rc);
229
230 if (port && C_CRTSCTS(tty))
231 cts_enable_byte = 1;
232
233 dev_dbg(&port->dev, "set_baud_rate: send second control message, data = %02X\n",
234 cts_enable_byte);
235 buf[0] = cts_enable_byte;
236 rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
237 MCT_U232_SET_CTS_REQUEST,
238 MCT_U232_SET_REQUEST_TYPE,
239 0, 0, buf, MCT_U232_SET_CTS_SIZE,
240 WDR_TIMEOUT);
241 if (rc < 0)
242 dev_err(&port->dev, "Sending USB device request code %d "
243 "failed (error = %d)\n", MCT_U232_SET_CTS_REQUEST, rc);
244
245 kfree(buf);
246 return rc;
247 } /* mct_u232_set_baud_rate */
248
mct_u232_set_line_ctrl(struct usb_serial_port * port,unsigned char lcr)249 static int mct_u232_set_line_ctrl(struct usb_serial_port *port,
250 unsigned char lcr)
251 {
252 int rc;
253 unsigned char *buf;
254
255 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
256 if (buf == NULL)
257 return -ENOMEM;
258
259 buf[0] = lcr;
260 rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
261 MCT_U232_SET_LINE_CTRL_REQUEST,
262 MCT_U232_SET_REQUEST_TYPE,
263 0, 0, buf, MCT_U232_SET_LINE_CTRL_SIZE,
264 WDR_TIMEOUT);
265 if (rc < 0)
266 dev_err(&port->dev, "Set LINE CTRL 0x%x failed (error = %d)\n", lcr, rc);
267 dev_dbg(&port->dev, "set_line_ctrl: 0x%x\n", lcr);
268 kfree(buf);
269 return rc;
270 } /* mct_u232_set_line_ctrl */
271
mct_u232_set_modem_ctrl(struct usb_serial_port * port,unsigned int control_state)272 static int mct_u232_set_modem_ctrl(struct usb_serial_port *port,
273 unsigned int control_state)
274 {
275 int rc;
276 unsigned char mcr;
277 unsigned char *buf;
278
279 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
280 if (buf == NULL)
281 return -ENOMEM;
282
283 mcr = MCT_U232_MCR_NONE;
284 if (control_state & TIOCM_DTR)
285 mcr |= MCT_U232_MCR_DTR;
286 if (control_state & TIOCM_RTS)
287 mcr |= MCT_U232_MCR_RTS;
288
289 buf[0] = mcr;
290 rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
291 MCT_U232_SET_MODEM_CTRL_REQUEST,
292 MCT_U232_SET_REQUEST_TYPE,
293 0, 0, buf, MCT_U232_SET_MODEM_CTRL_SIZE,
294 WDR_TIMEOUT);
295 kfree(buf);
296
297 dev_dbg(&port->dev, "set_modem_ctrl: state=0x%x ==> mcr=0x%x\n", control_state, mcr);
298
299 if (rc < 0) {
300 dev_err(&port->dev, "Set MODEM CTRL 0x%x failed (error = %d)\n", mcr, rc);
301 return rc;
302 }
303 return 0;
304 } /* mct_u232_set_modem_ctrl */
305
mct_u232_get_modem_stat(struct usb_serial_port * port,unsigned char * msr)306 static int mct_u232_get_modem_stat(struct usb_serial_port *port,
307 unsigned char *msr)
308 {
309 int rc;
310 unsigned char *buf;
311
312 buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
313 if (buf == NULL) {
314 *msr = 0;
315 return -ENOMEM;
316 }
317 rc = usb_control_msg(port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
318 MCT_U232_GET_MODEM_STAT_REQUEST,
319 MCT_U232_GET_REQUEST_TYPE,
320 0, 0, buf, MCT_U232_GET_MODEM_STAT_SIZE,
321 WDR_TIMEOUT);
322 if (rc < MCT_U232_GET_MODEM_STAT_SIZE) {
323 dev_err(&port->dev, "Get MODEM STATus failed (error = %d)\n", rc);
324
325 if (rc >= 0)
326 rc = -EIO;
327
328 *msr = 0;
329 } else {
330 *msr = buf[0];
331 }
332 dev_dbg(&port->dev, "get_modem_stat: 0x%x\n", *msr);
333 kfree(buf);
334 return rc;
335 } /* mct_u232_get_modem_stat */
336
mct_u232_msr_to_icount(struct async_icount * icount,unsigned char msr)337 static void mct_u232_msr_to_icount(struct async_icount *icount,
338 unsigned char msr)
339 {
340 /* Translate Control Line states */
341 if (msr & MCT_U232_MSR_DDSR)
342 icount->dsr++;
343 if (msr & MCT_U232_MSR_DCTS)
344 icount->cts++;
345 if (msr & MCT_U232_MSR_DRI)
346 icount->rng++;
347 if (msr & MCT_U232_MSR_DCD)
348 icount->dcd++;
349 } /* mct_u232_msr_to_icount */
350
mct_u232_msr_to_state(struct usb_serial_port * port,unsigned int * control_state,unsigned char msr)351 static void mct_u232_msr_to_state(struct usb_serial_port *port,
352 unsigned int *control_state, unsigned char msr)
353 {
354 /* Translate Control Line states */
355 if (msr & MCT_U232_MSR_DSR)
356 *control_state |= TIOCM_DSR;
357 else
358 *control_state &= ~TIOCM_DSR;
359 if (msr & MCT_U232_MSR_CTS)
360 *control_state |= TIOCM_CTS;
361 else
362 *control_state &= ~TIOCM_CTS;
363 if (msr & MCT_U232_MSR_RI)
364 *control_state |= TIOCM_RI;
365 else
366 *control_state &= ~TIOCM_RI;
367 if (msr & MCT_U232_MSR_CD)
368 *control_state |= TIOCM_CD;
369 else
370 *control_state &= ~TIOCM_CD;
371 dev_dbg(&port->dev, "msr_to_state: msr=0x%x ==> state=0x%x\n", msr, *control_state);
372 } /* mct_u232_msr_to_state */
373
374 /*
375 * Driver's tty interface functions
376 */
377
mct_u232_port_probe(struct usb_serial_port * port)378 static int mct_u232_port_probe(struct usb_serial_port *port)
379 {
380 struct usb_serial *serial = port->serial;
381 struct mct_u232_private *priv;
382
383 /* check first to simplify error handling */
384 if (!serial->port[1] || !serial->port[1]->interrupt_in_urb) {
385 dev_err(&port->dev, "expected endpoint missing\n");
386 return -ENODEV;
387 }
388
389 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
390 if (!priv)
391 return -ENOMEM;
392
393 /* Use second interrupt-in endpoint for reading. */
394 priv->read_urb = serial->port[1]->interrupt_in_urb;
395 priv->read_urb->context = port;
396
397 spin_lock_init(&priv->lock);
398
399 usb_set_serial_port_data(port, priv);
400
401 return 0;
402 }
403
mct_u232_port_remove(struct usb_serial_port * port)404 static void mct_u232_port_remove(struct usb_serial_port *port)
405 {
406 struct mct_u232_private *priv;
407
408 priv = usb_get_serial_port_data(port);
409 kfree(priv);
410 }
411
mct_u232_open(struct tty_struct * tty,struct usb_serial_port * port)412 static int mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port)
413 {
414 struct usb_serial *serial = port->serial;
415 struct mct_u232_private *priv = usb_get_serial_port_data(port);
416 int retval = 0;
417 unsigned int control_state;
418 unsigned long flags;
419 unsigned char last_lcr;
420 unsigned char last_msr;
421
422 /* Compensate for a hardware bug: although the Sitecom U232-P25
423 * device reports a maximum output packet size of 32 bytes,
424 * it seems to be able to accept only 16 bytes (and that's what
425 * SniffUSB says too...)
426 */
427 if (le16_to_cpu(serial->dev->descriptor.idProduct)
428 == MCT_U232_SITECOM_PID)
429 port->bulk_out_size = 16;
430
431 /* Do a defined restart: the normal serial device seems to
432 * always turn on DTR and RTS here, so do the same. I'm not
433 * sure if this is really necessary. But it should not harm
434 * either.
435 */
436 spin_lock_irqsave(&priv->lock, flags);
437 if (tty && C_BAUD(tty))
438 priv->control_state = TIOCM_DTR | TIOCM_RTS;
439 else
440 priv->control_state = 0;
441
442 priv->last_lcr = (MCT_U232_DATA_BITS_8 |
443 MCT_U232_PARITY_NONE |
444 MCT_U232_STOP_BITS_1);
445 control_state = priv->control_state;
446 last_lcr = priv->last_lcr;
447 spin_unlock_irqrestore(&priv->lock, flags);
448 mct_u232_set_modem_ctrl(port, control_state);
449 mct_u232_set_line_ctrl(port, last_lcr);
450
451 /* Read modem status and update control state */
452 mct_u232_get_modem_stat(port, &last_msr);
453 spin_lock_irqsave(&priv->lock, flags);
454 priv->last_msr = last_msr;
455 mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
456 spin_unlock_irqrestore(&priv->lock, flags);
457
458 retval = usb_submit_urb(priv->read_urb, GFP_KERNEL);
459 if (retval) {
460 dev_err(&port->dev,
461 "usb_submit_urb(read) failed pipe 0x%x err %d\n",
462 port->read_urb->pipe, retval);
463 goto error;
464 }
465
466 retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
467 if (retval) {
468 usb_kill_urb(priv->read_urb);
469 dev_err(&port->dev,
470 "usb_submit_urb(read int) failed pipe 0x%x err %d",
471 port->interrupt_in_urb->pipe, retval);
472 goto error;
473 }
474 return 0;
475
476 error:
477 return retval;
478 } /* mct_u232_open */
479
mct_u232_dtr_rts(struct usb_serial_port * port,int on)480 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on)
481 {
482 unsigned int control_state;
483 struct mct_u232_private *priv = usb_get_serial_port_data(port);
484
485 spin_lock_irq(&priv->lock);
486 if (on)
487 priv->control_state |= TIOCM_DTR | TIOCM_RTS;
488 else
489 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
490 control_state = priv->control_state;
491 spin_unlock_irq(&priv->lock);
492
493 mct_u232_set_modem_ctrl(port, control_state);
494 }
495
mct_u232_close(struct usb_serial_port * port)496 static void mct_u232_close(struct usb_serial_port *port)
497 {
498 struct mct_u232_private *priv = usb_get_serial_port_data(port);
499
500 usb_kill_urb(priv->read_urb);
501 usb_kill_urb(port->interrupt_in_urb);
502
503 usb_serial_generic_close(port);
504 } /* mct_u232_close */
505
506
mct_u232_read_int_callback(struct urb * urb)507 static void mct_u232_read_int_callback(struct urb *urb)
508 {
509 struct usb_serial_port *port = urb->context;
510 struct mct_u232_private *priv = usb_get_serial_port_data(port);
511 unsigned char *data = urb->transfer_buffer;
512 int retval;
513 int status = urb->status;
514 unsigned long flags;
515
516 switch (status) {
517 case 0:
518 /* success */
519 break;
520 case -ECONNRESET:
521 case -ENOENT:
522 case -ESHUTDOWN:
523 /* this urb is terminated, clean up */
524 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
525 __func__, status);
526 return;
527 default:
528 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
529 __func__, status);
530 goto exit;
531 }
532
533 usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
534
535 /*
536 * Work-a-round: handle the 'usual' bulk-in pipe here
537 */
538 if (urb->transfer_buffer_length > 2) {
539 if (urb->actual_length) {
540 tty_insert_flip_string(&port->port, data,
541 urb->actual_length);
542 tty_flip_buffer_push(&port->port);
543 }
544 goto exit;
545 }
546
547 /*
548 * The interrupt-in pipe signals exceptional conditions (modem line
549 * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
550 */
551 spin_lock_irqsave(&priv->lock, flags);
552 priv->last_msr = data[MCT_U232_MSR_INDEX];
553
554 /* Record Control Line states */
555 mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
556
557 mct_u232_msr_to_icount(&port->icount, priv->last_msr);
558
559 #if 0
560 /* Not yet handled. See belkin_sa.c for further information */
561 /* Now to report any errors */
562 priv->last_lsr = data[MCT_U232_LSR_INDEX];
563 /*
564 * fill in the flip buffer here, but I do not know the relation
565 * to the current/next receive buffer or characters. I need
566 * to look in to this before committing any code.
567 */
568 if (priv->last_lsr & MCT_U232_LSR_ERR) {
569 tty = tty_port_tty_get(&port->port);
570 /* Overrun Error */
571 if (priv->last_lsr & MCT_U232_LSR_OE) {
572 }
573 /* Parity Error */
574 if (priv->last_lsr & MCT_U232_LSR_PE) {
575 }
576 /* Framing Error */
577 if (priv->last_lsr & MCT_U232_LSR_FE) {
578 }
579 /* Break Indicator */
580 if (priv->last_lsr & MCT_U232_LSR_BI) {
581 }
582 tty_kref_put(tty);
583 }
584 #endif
585 wake_up_interruptible(&port->port.delta_msr_wait);
586 spin_unlock_irqrestore(&priv->lock, flags);
587 exit:
588 retval = usb_submit_urb(urb, GFP_ATOMIC);
589 if (retval)
590 dev_err(&port->dev,
591 "%s - usb_submit_urb failed with result %d\n",
592 __func__, retval);
593 } /* mct_u232_read_int_callback */
594
mct_u232_set_termios(struct tty_struct * tty,struct usb_serial_port * port,const struct ktermios * old_termios)595 static void mct_u232_set_termios(struct tty_struct *tty,
596 struct usb_serial_port *port,
597 const struct ktermios *old_termios)
598 {
599 struct usb_serial *serial = port->serial;
600 struct mct_u232_private *priv = usb_get_serial_port_data(port);
601 struct ktermios *termios = &tty->termios;
602 unsigned int cflag = termios->c_cflag;
603 unsigned int old_cflag = old_termios->c_cflag;
604 unsigned long flags;
605 unsigned int control_state;
606 unsigned char last_lcr;
607
608 /* get a local copy of the current port settings */
609 spin_lock_irqsave(&priv->lock, flags);
610 control_state = priv->control_state;
611 spin_unlock_irqrestore(&priv->lock, flags);
612 last_lcr = 0;
613
614 /*
615 * Update baud rate.
616 * Do not attempt to cache old rates and skip settings,
617 * disconnects screw such tricks up completely.
618 * Premature optimization is the root of all evil.
619 */
620
621 /* reassert DTR and RTS on transition from B0 */
622 if ((old_cflag & CBAUD) == B0) {
623 dev_dbg(&port->dev, "%s: baud was B0\n", __func__);
624 control_state |= TIOCM_DTR | TIOCM_RTS;
625 mct_u232_set_modem_ctrl(port, control_state);
626 }
627
628 mct_u232_set_baud_rate(tty, serial, port, tty_get_baud_rate(tty));
629
630 if ((cflag & CBAUD) == B0) {
631 dev_dbg(&port->dev, "%s: baud is B0\n", __func__);
632 /* Drop RTS and DTR */
633 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
634 mct_u232_set_modem_ctrl(port, control_state);
635 }
636
637 /*
638 * Update line control register (LCR)
639 */
640
641 /* set the parity */
642 if (cflag & PARENB)
643 last_lcr |= (cflag & PARODD) ?
644 MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
645 else
646 last_lcr |= MCT_U232_PARITY_NONE;
647
648 /* set the number of data bits */
649 switch (cflag & CSIZE) {
650 case CS5:
651 last_lcr |= MCT_U232_DATA_BITS_5; break;
652 case CS6:
653 last_lcr |= MCT_U232_DATA_BITS_6; break;
654 case CS7:
655 last_lcr |= MCT_U232_DATA_BITS_7; break;
656 case CS8:
657 last_lcr |= MCT_U232_DATA_BITS_8; break;
658 default:
659 dev_err(&port->dev,
660 "CSIZE was not CS5-CS8, using default of 8\n");
661 last_lcr |= MCT_U232_DATA_BITS_8;
662 break;
663 }
664
665 termios->c_cflag &= ~CMSPAR;
666
667 /* set the number of stop bits */
668 last_lcr |= (cflag & CSTOPB) ?
669 MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
670
671 mct_u232_set_line_ctrl(port, last_lcr);
672
673 /* save off the modified port settings */
674 spin_lock_irqsave(&priv->lock, flags);
675 priv->control_state = control_state;
676 priv->last_lcr = last_lcr;
677 spin_unlock_irqrestore(&priv->lock, flags);
678 } /* mct_u232_set_termios */
679
mct_u232_break_ctl(struct tty_struct * tty,int break_state)680 static int mct_u232_break_ctl(struct tty_struct *tty, int break_state)
681 {
682 struct usb_serial_port *port = tty->driver_data;
683 struct mct_u232_private *priv = usb_get_serial_port_data(port);
684 unsigned char lcr;
685 unsigned long flags;
686
687 spin_lock_irqsave(&priv->lock, flags);
688 lcr = priv->last_lcr;
689
690 if (break_state)
691 lcr |= MCT_U232_SET_BREAK;
692 spin_unlock_irqrestore(&priv->lock, flags);
693
694 return mct_u232_set_line_ctrl(port, lcr);
695 } /* mct_u232_break_ctl */
696
697
mct_u232_tiocmget(struct tty_struct * tty)698 static int mct_u232_tiocmget(struct tty_struct *tty)
699 {
700 struct usb_serial_port *port = tty->driver_data;
701 struct mct_u232_private *priv = usb_get_serial_port_data(port);
702 unsigned int control_state;
703 unsigned long flags;
704
705 spin_lock_irqsave(&priv->lock, flags);
706 control_state = priv->control_state;
707 spin_unlock_irqrestore(&priv->lock, flags);
708
709 return control_state;
710 }
711
mct_u232_tiocmset(struct tty_struct * tty,unsigned int set,unsigned int clear)712 static int mct_u232_tiocmset(struct tty_struct *tty,
713 unsigned int set, unsigned int clear)
714 {
715 struct usb_serial_port *port = tty->driver_data;
716 struct mct_u232_private *priv = usb_get_serial_port_data(port);
717 unsigned int control_state;
718 unsigned long flags;
719
720 spin_lock_irqsave(&priv->lock, flags);
721 control_state = priv->control_state;
722
723 if (set & TIOCM_RTS)
724 control_state |= TIOCM_RTS;
725 if (set & TIOCM_DTR)
726 control_state |= TIOCM_DTR;
727 if (clear & TIOCM_RTS)
728 control_state &= ~TIOCM_RTS;
729 if (clear & TIOCM_DTR)
730 control_state &= ~TIOCM_DTR;
731
732 priv->control_state = control_state;
733 spin_unlock_irqrestore(&priv->lock, flags);
734 return mct_u232_set_modem_ctrl(port, control_state);
735 }
736
mct_u232_throttle(struct tty_struct * tty)737 static void mct_u232_throttle(struct tty_struct *tty)
738 {
739 struct usb_serial_port *port = tty->driver_data;
740 struct mct_u232_private *priv = usb_get_serial_port_data(port);
741 unsigned int control_state;
742
743 spin_lock_irq(&priv->lock);
744 priv->rx_flags |= THROTTLED;
745 if (C_CRTSCTS(tty)) {
746 priv->control_state &= ~TIOCM_RTS;
747 control_state = priv->control_state;
748 spin_unlock_irq(&priv->lock);
749 mct_u232_set_modem_ctrl(port, control_state);
750 } else {
751 spin_unlock_irq(&priv->lock);
752 }
753 }
754
mct_u232_unthrottle(struct tty_struct * tty)755 static void mct_u232_unthrottle(struct tty_struct *tty)
756 {
757 struct usb_serial_port *port = tty->driver_data;
758 struct mct_u232_private *priv = usb_get_serial_port_data(port);
759 unsigned int control_state;
760
761 spin_lock_irq(&priv->lock);
762 if ((priv->rx_flags & THROTTLED) && C_CRTSCTS(tty)) {
763 priv->rx_flags &= ~THROTTLED;
764 priv->control_state |= TIOCM_RTS;
765 control_state = priv->control_state;
766 spin_unlock_irq(&priv->lock);
767 mct_u232_set_modem_ctrl(port, control_state);
768 } else {
769 spin_unlock_irq(&priv->lock);
770 }
771 }
772
773 module_usb_serial_driver(serial_drivers, id_table);
774
775 MODULE_AUTHOR(DRIVER_AUTHOR);
776 MODULE_DESCRIPTION(DRIVER_DESC);
777 MODULE_LICENSE("GPL");
778