Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/drivers/usb/serial/mct_u232.c

  1 /*
  2  * MCT (Magic Control Technology Corp.) USB RS232 Converter Driver
  3  *
  4  *   Copyright (C) 2000 Wolfgang Grandegger (wolfgang@ces.ch)
  5  *
  6  *   This program is free software; you can redistribute it and/or modify
  7  *   it under the terms of the GNU General Public License as published by
  8  *   the Free Software Foundation; either version 2 of the License, or
  9  *   (at your option) any later version.
 10  *
 11  * This program is largely derived from the Belkin USB Serial Adapter Driver
 12  * (see belkin_sa.[ch]). All of the information about the device was acquired
 13  * by using SniffUSB on Windows98. For technical details see mct_u232.h.
 14  *
 15  * William G. Greathouse and Greg Kroah-Hartman provided great help on how to
 16  * do the reverse engineering and how to write a USB serial device driver.
 17  *
 18  * TO BE DONE, TO BE CHECKED:
 19  *   DTR/RTS signal handling may be incomplete or incorrect. I have mainly
 20  *   implemented what I have seen with SniffUSB or found in belkin_sa.c.
 21  *   For further TODOs check also belkin_sa.c.
 22  */
 23 
 24 #include <linux/kernel.h>
 25 #include <linux/errno.h>
 26 #include <linux/slab.h>
 27 #include <linux/tty.h>
 28 #include <linux/tty_driver.h>
 29 #include <linux/tty_flip.h>
 30 #include <linux/module.h>
 31 #include <linux/spinlock.h>
 32 #include <linux/uaccess.h>
 33 #include <asm/unaligned.h>
 34 #include <linux/usb.h>
 35 #include <linux/usb/serial.h>
 36 #include <linux/serial.h>
 37 #include "mct_u232.h"
 38 
 39 #define DRIVER_AUTHOR "Wolfgang Grandegger <wolfgang@ces.ch>"
 40 #define DRIVER_DESC "Magic Control Technology USB-RS232 converter driver"
 41 
 42 /*
 43  * Function prototypes
 44  */
 45 static int  mct_u232_port_probe(struct usb_serial_port *port);
 46 static int  mct_u232_port_remove(struct usb_serial_port *remove);
 47 static int  mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port);
 48 static void mct_u232_close(struct usb_serial_port *port);
 49 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on);
 50 static void mct_u232_read_int_callback(struct urb *urb);
 51 static void mct_u232_set_termios(struct tty_struct *tty,
 52                         struct usb_serial_port *port, struct ktermios *old);
 53 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state);
 54 static int  mct_u232_tiocmget(struct tty_struct *tty);
 55 static int  mct_u232_tiocmset(struct tty_struct *tty,
 56                         unsigned int set, unsigned int clear);
 57 static void mct_u232_throttle(struct tty_struct *tty);
 58 static void mct_u232_unthrottle(struct tty_struct *tty);
 59 
 60 
 61 /*
 62  * All of the device info needed for the MCT USB-RS232 converter.
 63  */
 64 static const struct usb_device_id id_table[] = {
 65         { USB_DEVICE(MCT_U232_VID, MCT_U232_PID) },
 66         { USB_DEVICE(MCT_U232_VID, MCT_U232_SITECOM_PID) },
 67         { USB_DEVICE(MCT_U232_VID, MCT_U232_DU_H3SP_PID) },
 68         { USB_DEVICE(MCT_U232_BELKIN_F5U109_VID, MCT_U232_BELKIN_F5U109_PID) },
 69         { }             /* Terminating entry */
 70 };
 71 MODULE_DEVICE_TABLE(usb, id_table);
 72 
 73 static struct usb_serial_driver mct_u232_device = {
 74         .driver = {
 75                 .owner =        THIS_MODULE,
 76                 .name =         "mct_u232",
 77         },
 78         .description =       "MCT U232",
 79         .id_table =          id_table,
 80         .num_ports =         1,
 81         .open =              mct_u232_open,
 82         .close =             mct_u232_close,
 83         .dtr_rts =           mct_u232_dtr_rts,
 84         .throttle =          mct_u232_throttle,
 85         .unthrottle =        mct_u232_unthrottle,
 86         .read_int_callback = mct_u232_read_int_callback,
 87         .set_termios =       mct_u232_set_termios,
 88         .break_ctl =         mct_u232_break_ctl,
 89         .tiocmget =          mct_u232_tiocmget,
 90         .tiocmset =          mct_u232_tiocmset,
 91         .tiocmiwait =        usb_serial_generic_tiocmiwait,
 92         .port_probe =        mct_u232_port_probe,
 93         .port_remove =       mct_u232_port_remove,
 94         .get_icount =        usb_serial_generic_get_icount,
 95 };
 96 
 97 static struct usb_serial_driver * const serial_drivers[] = {
 98         &mct_u232_device, NULL
 99 };
100 
101 struct mct_u232_private {
102         struct urb *read_urb;
103         spinlock_t lock;
104         unsigned int         control_state; /* Modem Line Setting (TIOCM) */
105         unsigned char        last_lcr;      /* Line Control Register */
106         unsigned char        last_lsr;      /* Line Status Register */
107         unsigned char        last_msr;      /* Modem Status Register */
108         unsigned int         rx_flags;      /* Throttling flags */
109 };
110 
111 #define THROTTLED               0x01
112 
113 /*
114  * Handle vendor specific USB requests
115  */
116 
117 #define WDR_TIMEOUT 5000 /* default urb timeout */
118 
119 /*
120  * Later day 2.6.0-test kernels have new baud rates like B230400 which
121  * we do not know how to support. We ignore them for the moment.
122  */
123 static int mct_u232_calculate_baud_rate(struct usb_serial *serial,
124                                         speed_t value, speed_t *result)
125 {
126         *result = value;
127 
128         if (le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_SITECOM_PID
129                 || le16_to_cpu(serial->dev->descriptor.idProduct) == MCT_U232_BELKIN_F5U109_PID) {
130                 switch (value) {
131                 case 300:
132                         return 0x01;
133                 case 600:
134                         return 0x02; /* this one not tested */
135                 case 1200:
136                         return 0x03;
137                 case 2400:
138                         return 0x04;
139                 case 4800:
140                         return 0x06;
141                 case 9600:
142                         return 0x08;
143                 case 19200:
144                         return 0x09;
145                 case 38400:
146                         return 0x0a;
147                 case 57600:
148                         return 0x0b;
149                 case 115200:
150                         return 0x0c;
151                 default:
152                         *result = 9600;
153                         return 0x08;
154                 }
155         } else {
156                 /* FIXME: Can we use any divider - should we do
157                    divider = 115200/value;
158                    real baud = 115200/divider */
159                 switch (value) {
160                 case 300: break;
161                 case 600: break;
162                 case 1200: break;
163                 case 2400: break;
164                 case 4800: break;
165                 case 9600: break;
166                 case 19200: break;
167                 case 38400: break;
168                 case 57600: break;
169                 case 115200: break;
170                 default:
171                         value = 9600;
172                         *result = 9600;
173                 }
174                 return 115200/value;
175         }
176 }
177 
178 static int mct_u232_set_baud_rate(struct tty_struct *tty,
179         struct usb_serial *serial, struct usb_serial_port *port, speed_t value)
180 {
181         unsigned int divisor;
182         int rc;
183         unsigned char *buf;
184         unsigned char cts_enable_byte = 0;
185         speed_t speed;
186 
187         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
188         if (buf == NULL)
189                 return -ENOMEM;
190 
191         divisor = mct_u232_calculate_baud_rate(serial, value, &speed);
192         put_unaligned_le32(cpu_to_le32(divisor), buf);
193         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
194                                 MCT_U232_SET_BAUD_RATE_REQUEST,
195                                 MCT_U232_SET_REQUEST_TYPE,
196                                 0, 0, buf, MCT_U232_SET_BAUD_RATE_SIZE,
197                                 WDR_TIMEOUT);
198         if (rc < 0)     /*FIXME: What value speed results */
199                 dev_err(&port->dev, "Set BAUD RATE %d failed (error = %d)\n",
200                         value, rc);
201         else
202                 tty_encode_baud_rate(tty, speed, speed);
203         dev_dbg(&port->dev, "set_baud_rate: value: 0x%x, divisor: 0x%x\n", value, divisor);
204 
205         /* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
206            always sends two extra USB 'device request' messages after the
207            'baud rate change' message.  The actual functionality of the
208            request codes in these messages is not fully understood but these
209            particular codes are never seen in any operation besides a baud
210            rate change.  Both of these messages send a single byte of data.
211            In the first message, the value of this byte is always zero.
212 
213            The second message has been determined experimentally to control
214            whether data will be transmitted to a device which is not asserting
215            the 'CTS' signal.  If the second message's data byte is zero, data
216            will be transmitted even if 'CTS' is not asserted (i.e. no hardware
217            flow control).  if the second message's data byte is nonzero (a
218            value of 1 is used by this driver), data will not be transmitted to
219            a device which is not asserting 'CTS'.
220         */
221 
222         buf[0] = 0;
223         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
224                                 MCT_U232_SET_UNKNOWN1_REQUEST,
225                                 MCT_U232_SET_REQUEST_TYPE,
226                                 0, 0, buf, MCT_U232_SET_UNKNOWN1_SIZE,
227                                 WDR_TIMEOUT);
228         if (rc < 0)
229                 dev_err(&port->dev, "Sending USB device request code %d "
230                         "failed (error = %d)\n", MCT_U232_SET_UNKNOWN1_REQUEST,
231                         rc);
232 
233         if (port && C_CRTSCTS(tty))
234            cts_enable_byte = 1;
235 
236         dev_dbg(&port->dev, "set_baud_rate: send second control message, data = %02X\n",
237                 cts_enable_byte);
238         buf[0] = cts_enable_byte;
239         rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
240                         MCT_U232_SET_CTS_REQUEST,
241                         MCT_U232_SET_REQUEST_TYPE,
242                         0, 0, buf, MCT_U232_SET_CTS_SIZE,
243                         WDR_TIMEOUT);
244         if (rc < 0)
245                 dev_err(&port->dev, "Sending USB device request code %d "
246                         "failed (error = %d)\n", MCT_U232_SET_CTS_REQUEST, rc);
247 
248         kfree(buf);
249         return rc;
250 } /* mct_u232_set_baud_rate */
251 
252 static int mct_u232_set_line_ctrl(struct usb_serial_port *port,
253                                   unsigned char lcr)
254 {
255         int rc;
256         unsigned char *buf;
257 
258         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
259         if (buf == NULL)
260                 return -ENOMEM;
261 
262         buf[0] = lcr;
263         rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
264                         MCT_U232_SET_LINE_CTRL_REQUEST,
265                         MCT_U232_SET_REQUEST_TYPE,
266                         0, 0, buf, MCT_U232_SET_LINE_CTRL_SIZE,
267                         WDR_TIMEOUT);
268         if (rc < 0)
269                 dev_err(&port->dev, "Set LINE CTRL 0x%x failed (error = %d)\n", lcr, rc);
270         dev_dbg(&port->dev, "set_line_ctrl: 0x%x\n", lcr);
271         kfree(buf);
272         return rc;
273 } /* mct_u232_set_line_ctrl */
274 
275 static int mct_u232_set_modem_ctrl(struct usb_serial_port *port,
276                                    unsigned int control_state)
277 {
278         int rc;
279         unsigned char mcr;
280         unsigned char *buf;
281 
282         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
283         if (buf == NULL)
284                 return -ENOMEM;
285 
286         mcr = MCT_U232_MCR_NONE;
287         if (control_state & TIOCM_DTR)
288                 mcr |= MCT_U232_MCR_DTR;
289         if (control_state & TIOCM_RTS)
290                 mcr |= MCT_U232_MCR_RTS;
291 
292         buf[0] = mcr;
293         rc = usb_control_msg(port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
294                         MCT_U232_SET_MODEM_CTRL_REQUEST,
295                         MCT_U232_SET_REQUEST_TYPE,
296                         0, 0, buf, MCT_U232_SET_MODEM_CTRL_SIZE,
297                         WDR_TIMEOUT);
298         kfree(buf);
299 
300         dev_dbg(&port->dev, "set_modem_ctrl: state=0x%x ==> mcr=0x%x\n", control_state, mcr);
301 
302         if (rc < 0) {
303                 dev_err(&port->dev, "Set MODEM CTRL 0x%x failed (error = %d)\n", mcr, rc);
304                 return rc;
305         }
306         return 0;
307 } /* mct_u232_set_modem_ctrl */
308 
309 static int mct_u232_get_modem_stat(struct usb_serial_port *port,
310                                    unsigned char *msr)
311 {
312         int rc;
313         unsigned char *buf;
314 
315         buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
316         if (buf == NULL) {
317                 *msr = 0;
318                 return -ENOMEM;
319         }
320         rc = usb_control_msg(port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
321                         MCT_U232_GET_MODEM_STAT_REQUEST,
322                         MCT_U232_GET_REQUEST_TYPE,
323                         0, 0, buf, MCT_U232_GET_MODEM_STAT_SIZE,
324                         WDR_TIMEOUT);
325         if (rc < 0) {
326                 dev_err(&port->dev, "Get MODEM STATus failed (error = %d)\n", rc);
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 
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 
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 
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 
403 static int 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         return 0;
411 }
412 
413 static int  mct_u232_open(struct tty_struct *tty, struct usb_serial_port *port)
414 {
415         struct usb_serial *serial = port->serial;
416         struct mct_u232_private *priv = usb_get_serial_port_data(port);
417         int retval = 0;
418         unsigned int control_state;
419         unsigned long flags;
420         unsigned char last_lcr;
421         unsigned char last_msr;
422 
423         /* Compensate for a hardware bug: although the Sitecom U232-P25
424          * device reports a maximum output packet size of 32 bytes,
425          * it seems to be able to accept only 16 bytes (and that's what
426          * SniffUSB says too...)
427          */
428         if (le16_to_cpu(serial->dev->descriptor.idProduct)
429                                                 == MCT_U232_SITECOM_PID)
430                 port->bulk_out_size = 16;
431 
432         /* Do a defined restart: the normal serial device seems to
433          * always turn on DTR and RTS here, so do the same. I'm not
434          * sure if this is really necessary. But it should not harm
435          * either.
436          */
437         spin_lock_irqsave(&priv->lock, flags);
438         if (tty && C_BAUD(tty))
439                 priv->control_state = TIOCM_DTR | TIOCM_RTS;
440         else
441                 priv->control_state = 0;
442 
443         priv->last_lcr = (MCT_U232_DATA_BITS_8 |
444                           MCT_U232_PARITY_NONE |
445                           MCT_U232_STOP_BITS_1);
446         control_state = priv->control_state;
447         last_lcr = priv->last_lcr;
448         spin_unlock_irqrestore(&priv->lock, flags);
449         mct_u232_set_modem_ctrl(port, control_state);
450         mct_u232_set_line_ctrl(port, last_lcr);
451 
452         /* Read modem status and update control state */
453         mct_u232_get_modem_stat(port, &last_msr);
454         spin_lock_irqsave(&priv->lock, flags);
455         priv->last_msr = last_msr;
456         mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
457         spin_unlock_irqrestore(&priv->lock, flags);
458 
459         retval = usb_submit_urb(priv->read_urb, GFP_KERNEL);
460         if (retval) {
461                 dev_err(&port->dev,
462                         "usb_submit_urb(read) failed pipe 0x%x err %d\n",
463                         port->read_urb->pipe, retval);
464                 goto error;
465         }
466 
467         retval = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
468         if (retval) {
469                 usb_kill_urb(priv->read_urb);
470                 dev_err(&port->dev,
471                         "usb_submit_urb(read int) failed pipe 0x%x err %d",
472                         port->interrupt_in_urb->pipe, retval);
473                 goto error;
474         }
475         return 0;
476 
477 error:
478         return retval;
479 } /* mct_u232_open */
480 
481 static void mct_u232_dtr_rts(struct usb_serial_port *port, int on)
482 {
483         unsigned int control_state;
484         struct mct_u232_private *priv = usb_get_serial_port_data(port);
485 
486         spin_lock_irq(&priv->lock);
487         if (on)
488                 priv->control_state |= TIOCM_DTR | TIOCM_RTS;
489         else
490                 priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
491         control_state = priv->control_state;
492         spin_unlock_irq(&priv->lock);
493 
494         mct_u232_set_modem_ctrl(port, control_state);
495 }
496 
497 static void mct_u232_close(struct usb_serial_port *port)
498 {
499         struct mct_u232_private *priv = usb_get_serial_port_data(port);
500 
501         usb_kill_urb(priv->read_urb);
502         usb_kill_urb(port->interrupt_in_urb);
503 
504         usb_serial_generic_close(port);
505 } /* mct_u232_close */
506 
507 
508 static void mct_u232_read_int_callback(struct urb *urb)
509 {
510         struct usb_serial_port *port = urb->context;
511         struct mct_u232_private *priv = usb_get_serial_port_data(port);
512         unsigned char *data = urb->transfer_buffer;
513         int retval;
514         int status = urb->status;
515         unsigned long flags;
516 
517         switch (status) {
518         case 0:
519                 /* success */
520                 break;
521         case -ECONNRESET:
522         case -ENOENT:
523         case -ESHUTDOWN:
524                 /* this urb is terminated, clean up */
525                 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
526                         __func__, status);
527                 return;
528         default:
529                 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
530                         __func__, status);
531                 goto exit;
532         }
533 
534         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
535 
536         /*
537          * Work-a-round: handle the 'usual' bulk-in pipe here
538          */
539         if (urb->transfer_buffer_length > 2) {
540                 if (urb->actual_length) {
541                         tty_insert_flip_string(&port->port, data,
542                                         urb->actual_length);
543                         tty_flip_buffer_push(&port->port);
544                 }
545                 goto exit;
546         }
547 
548         /*
549          * The interrupt-in pipe signals exceptional conditions (modem line
550          * signal changes and errors). data[0] holds MSR, data[1] holds LSR.
551          */
552         spin_lock_irqsave(&priv->lock, flags);
553         priv->last_msr = data[MCT_U232_MSR_INDEX];
554 
555         /* Record Control Line states */
556         mct_u232_msr_to_state(port, &priv->control_state, priv->last_msr);
557 
558         mct_u232_msr_to_icount(&port->icount, priv->last_msr);
559 
560 #if 0
561         /* Not yet handled. See belkin_sa.c for further information */
562         /* Now to report any errors */
563         priv->last_lsr = data[MCT_U232_LSR_INDEX];
564         /*
565          * fill in the flip buffer here, but I do not know the relation
566          * to the current/next receive buffer or characters.  I need
567          * to look in to this before committing any code.
568          */
569         if (priv->last_lsr & MCT_U232_LSR_ERR) {
570                 tty = tty_port_tty_get(&port->port);
571                 /* Overrun Error */
572                 if (priv->last_lsr & MCT_U232_LSR_OE) {
573                 }
574                 /* Parity Error */
575                 if (priv->last_lsr & MCT_U232_LSR_PE) {
576                 }
577                 /* Framing Error */
578                 if (priv->last_lsr & MCT_U232_LSR_FE) {
579                 }
580                 /* Break Indicator */
581                 if (priv->last_lsr & MCT_U232_LSR_BI) {
582                 }
583                 tty_kref_put(tty);
584         }
585 #endif
586         wake_up_interruptible(&port->port.delta_msr_wait);
587         spin_unlock_irqrestore(&priv->lock, flags);
588 exit:
589         retval = usb_submit_urb(urb, GFP_ATOMIC);
590         if (retval)
591                 dev_err(&port->dev,
592                         "%s - usb_submit_urb failed with result %d\n",
593                         __func__, retval);
594 } /* mct_u232_read_int_callback */
595 
596 static void mct_u232_set_termios(struct tty_struct *tty,
597                                  struct usb_serial_port *port,
598                                  struct ktermios *old_termios)
599 {
600         struct usb_serial *serial = port->serial;
601         struct mct_u232_private *priv = usb_get_serial_port_data(port);
602         struct ktermios *termios = &tty->termios;
603         unsigned int cflag = termios->c_cflag;
604         unsigned int old_cflag = old_termios->c_cflag;
605         unsigned long flags;
606         unsigned int control_state;
607         unsigned char last_lcr;
608 
609         /* get a local copy of the current port settings */
610         spin_lock_irqsave(&priv->lock, flags);
611         control_state = priv->control_state;
612         spin_unlock_irqrestore(&priv->lock, flags);
613         last_lcr = 0;
614 
615         /*
616          * Update baud rate.
617          * Do not attempt to cache old rates and skip settings,
618          * disconnects screw such tricks up completely.
619          * Premature optimization is the root of all evil.
620          */
621 
622         /* reassert DTR and RTS on transition from B0 */
623         if ((old_cflag & CBAUD) == B0) {
624                 dev_dbg(&port->dev, "%s: baud was B0\n", __func__);
625                 control_state |= TIOCM_DTR | TIOCM_RTS;
626                 mct_u232_set_modem_ctrl(port, control_state);
627         }
628 
629         mct_u232_set_baud_rate(tty, serial, port, tty_get_baud_rate(tty));
630 
631         if ((cflag & CBAUD) == B0) {
632                 dev_dbg(&port->dev, "%s: baud is B0\n", __func__);
633                 /* Drop RTS and DTR */
634                 control_state &= ~(TIOCM_DTR | TIOCM_RTS);
635                 mct_u232_set_modem_ctrl(port, control_state);
636         }
637 
638         /*
639          * Update line control register (LCR)
640          */
641 
642         /* set the parity */
643         if (cflag & PARENB)
644                 last_lcr |= (cflag & PARODD) ?
645                         MCT_U232_PARITY_ODD : MCT_U232_PARITY_EVEN;
646         else
647                 last_lcr |= MCT_U232_PARITY_NONE;
648 
649         /* set the number of data bits */
650         switch (cflag & CSIZE) {
651         case CS5:
652                 last_lcr |= MCT_U232_DATA_BITS_5; break;
653         case CS6:
654                 last_lcr |= MCT_U232_DATA_BITS_6; break;
655         case CS7:
656                 last_lcr |= MCT_U232_DATA_BITS_7; break;
657         case CS8:
658                 last_lcr |= MCT_U232_DATA_BITS_8; break;
659         default:
660                 dev_err(&port->dev,
661                         "CSIZE was not CS5-CS8, using default of 8\n");
662                 last_lcr |= MCT_U232_DATA_BITS_8;
663                 break;
664         }
665 
666         termios->c_cflag &= ~CMSPAR;
667 
668         /* set the number of stop bits */
669         last_lcr |= (cflag & CSTOPB) ?
670                 MCT_U232_STOP_BITS_2 : MCT_U232_STOP_BITS_1;
671 
672         mct_u232_set_line_ctrl(port, last_lcr);
673 
674         /* save off the modified port settings */
675         spin_lock_irqsave(&priv->lock, flags);
676         priv->control_state = control_state;
677         priv->last_lcr = last_lcr;
678         spin_unlock_irqrestore(&priv->lock, flags);
679 } /* mct_u232_set_termios */
680 
681 static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
682 {
683         struct usb_serial_port *port = tty->driver_data;
684         struct mct_u232_private *priv = usb_get_serial_port_data(port);
685         unsigned char lcr;
686         unsigned long flags;
687 
688         spin_lock_irqsave(&priv->lock, flags);
689         lcr = priv->last_lcr;
690 
691         if (break_state)
692                 lcr |= MCT_U232_SET_BREAK;
693         spin_unlock_irqrestore(&priv->lock, flags);
694 
695         mct_u232_set_line_ctrl(port, lcr);
696 } /* mct_u232_break_ctl */
697 
698 
699 static int mct_u232_tiocmget(struct tty_struct *tty)
700 {
701         struct usb_serial_port *port = tty->driver_data;
702         struct mct_u232_private *priv = usb_get_serial_port_data(port);
703         unsigned int control_state;
704         unsigned long flags;
705 
706         spin_lock_irqsave(&priv->lock, flags);
707         control_state = priv->control_state;
708         spin_unlock_irqrestore(&priv->lock, flags);
709 
710         return control_state;
711 }
712 
713 static int mct_u232_tiocmset(struct tty_struct *tty,
714                               unsigned int set, unsigned int clear)
715 {
716         struct usb_serial_port *port = tty->driver_data;
717         struct mct_u232_private *priv = usb_get_serial_port_data(port);
718         unsigned int control_state;
719         unsigned long flags;
720 
721         spin_lock_irqsave(&priv->lock, flags);
722         control_state = priv->control_state;
723 
724         if (set & TIOCM_RTS)
725                 control_state |= TIOCM_RTS;
726         if (set & TIOCM_DTR)
727                 control_state |= TIOCM_DTR;
728         if (clear & TIOCM_RTS)
729                 control_state &= ~TIOCM_RTS;
730         if (clear & TIOCM_DTR)
731                 control_state &= ~TIOCM_DTR;
732 
733         priv->control_state = control_state;
734         spin_unlock_irqrestore(&priv->lock, flags);
735         return mct_u232_set_modem_ctrl(port, control_state);
736 }
737 
738 static void mct_u232_throttle(struct tty_struct *tty)
739 {
740         struct usb_serial_port *port = tty->driver_data;
741         struct mct_u232_private *priv = usb_get_serial_port_data(port);
742         unsigned int control_state;
743 
744         spin_lock_irq(&priv->lock);
745         priv->rx_flags |= THROTTLED;
746         if (C_CRTSCTS(tty)) {
747                 priv->control_state &= ~TIOCM_RTS;
748                 control_state = priv->control_state;
749                 spin_unlock_irq(&priv->lock);
750                 mct_u232_set_modem_ctrl(port, control_state);
751         } else {
752                 spin_unlock_irq(&priv->lock);
753         }
754 }
755 
756 static void mct_u232_unthrottle(struct tty_struct *tty)
757 {
758         struct usb_serial_port *port = tty->driver_data;
759         struct mct_u232_private *priv = usb_get_serial_port_data(port);
760         unsigned int control_state;
761 
762         spin_lock_irq(&priv->lock);
763         if ((priv->rx_flags & THROTTLED) && C_CRTSCTS(tty)) {
764                 priv->rx_flags &= ~THROTTLED;
765                 priv->control_state |= TIOCM_RTS;
766                 control_state = priv->control_state;
767                 spin_unlock_irq(&priv->lock);
768                 mct_u232_set_modem_ctrl(port, control_state);
769         } else {
770                 spin_unlock_irq(&priv->lock);
771         }
772 }
773 
774 module_usb_serial_driver(serial_drivers, id_table);
775 
776 MODULE_AUTHOR(DRIVER_AUTHOR);
777 MODULE_DESCRIPTION(DRIVER_DESC);
778 MODULE_LICENSE("GPL");
779 

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