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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
  3  *
  4  * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
  5  * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
  6  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
  7  * Copyright (C) 2003 IBM Corp.
  8  *
  9  * Many thanks to the authors of pl2303 driver: all functions in this file
 10  * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
 11  *
 12  * Warning! You use this driver on your own risk! The only official
 13  * description of this device I have is datasheet from manufacturer,
 14  * and it doesn't contain almost any information needed to write a driver.
 15  * Almost all knowlegde used while writing this driver was gathered by:
 16  *  - analyzing traffic between device and the M$ Windows 2000 driver,
 17  *  - trying different bit combinations and checking pin states
 18  *    with a voltmeter,
 19  *  - receiving malformed frames and producing buffer overflows
 20  *    to learn how errors are reported,
 21  * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
 22  * CONNECTED TO IT!
 23  *
 24  * This program is free software; you can redistribute it and/or modify
 25  * it under the terms of the GNU General Public License as published by
 26  * the Free Software Foundation; either version 2 of the License.
 27  *
 28  * See Documentation/usb/usb-serial.txt for more information on using this
 29  * driver
 30  *
 31  * TODO:
 32  *  - implement correct flushing for ioctls and oti6858_close()
 33  *  - check how errors (rx overflow, parity error, framing error) are reported
 34  *  - implement oti6858_break_ctl()
 35  *  - implement more ioctls
 36  *  - test/implement flow control
 37  *  - allow setting custom baud rates
 38  */
 39 
 40 #include <linux/kernel.h>
 41 #include <linux/errno.h>
 42 #include <linux/init.h>
 43 #include <linux/slab.h>
 44 #include <linux/tty.h>
 45 #include <linux/tty_driver.h>
 46 #include <linux/tty_flip.h>
 47 #include <linux/serial.h>
 48 #include <linux/module.h>
 49 #include <linux/moduleparam.h>
 50 #include <linux/spinlock.h>
 51 #include <linux/usb.h>
 52 #include <linux/usb/serial.h>
 53 #include <linux/uaccess.h>
 54 #include "oti6858.h"
 55 
 56 #define OTI6858_DESCRIPTION \
 57         "Ours Technology Inc. OTi-6858 USB to serial adapter driver"
 58 #define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
 59 #define OTI6858_VERSION "0.1"
 60 
 61 static struct usb_device_id id_table [] = {
 62         { USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
 63         { }
 64 };
 65 
 66 MODULE_DEVICE_TABLE(usb, id_table);
 67 
 68 static struct usb_driver oti6858_driver = {
 69         .name =         "oti6858",
 70         .probe =        usb_serial_probe,
 71         .disconnect =   usb_serial_disconnect,
 72         .id_table =     id_table,
 73         .no_dynamic_id =        1,
 74 };
 75 
 76 static int debug;
 77 
 78 
 79 /* buffering code, copied from pl2303 driver */
 80 #define PL2303_BUF_SIZE         1024
 81 #define PL2303_TMP_BUF_SIZE     1024
 82 
 83 struct oti6858_buf {
 84         unsigned int    buf_size;
 85         char            *buf_buf;
 86         char            *buf_get;
 87         char            *buf_put;
 88 };
 89 
 90 /* requests */
 91 #define OTI6858_REQ_GET_STATUS          (USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
 92 #define OTI6858_REQ_T_GET_STATUS        0x01
 93 
 94 #define OTI6858_REQ_SET_LINE            (USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
 95 #define OTI6858_REQ_T_SET_LINE          0x00
 96 
 97 #define OTI6858_REQ_CHECK_TXBUFF        (USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
 98 #define OTI6858_REQ_T_CHECK_TXBUFF      0x00
 99 
100 /* format of the control packet */
101 struct oti6858_control_pkt {
102         __le16  divisor;        /* baud rate = 96000000 / (16 * divisor), LE */
103 #define OTI6858_MAX_BAUD_RATE   3000000
104         u8      frame_fmt;
105 #define FMT_STOP_BITS_MASK      0xc0
106 #define FMT_STOP_BITS_1         0x00
107 #define FMT_STOP_BITS_2         0x40    /* 1.5 stop bits if FMT_DATA_BITS_5 */
108 #define FMT_PARITY_MASK         0x38
109 #define FMT_PARITY_NONE         0x00
110 #define FMT_PARITY_ODD          0x08
111 #define FMT_PARITY_EVEN         0x18
112 #define FMT_PARITY_MARK         0x28
113 #define FMT_PARITY_SPACE        0x38
114 #define FMT_DATA_BITS_MASK      0x03
115 #define FMT_DATA_BITS_5         0x00
116 #define FMT_DATA_BITS_6         0x01
117 #define FMT_DATA_BITS_7         0x02
118 #define FMT_DATA_BITS_8         0x03
119         u8      something;      /* always equals 0x43 */
120         u8      control;        /* settings of flow control lines */
121 #define CONTROL_MASK            0x0c
122 #define CONTROL_DTR_HIGH        0x08
123 #define CONTROL_RTS_HIGH        0x04
124         u8      tx_status;
125 #define TX_BUFFER_EMPTIED       0x09
126         u8      pin_state;
127 #define PIN_MASK                0x3f
128 #define PIN_RTS                 0x20    /* output pin */
129 #define PIN_CTS                 0x10    /* input pin, active low */
130 #define PIN_DSR                 0x08    /* input pin, active low */
131 #define PIN_DTR                 0x04    /* output pin */
132 #define PIN_RI                  0x02    /* input pin, active low */
133 #define PIN_DCD                 0x01    /* input pin, active low */
134         u8      rx_bytes_avail;         /* number of bytes in rx buffer */;
135 };
136 
137 #define OTI6858_CTRL_PKT_SIZE   sizeof(struct oti6858_control_pkt)
138 #define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
139         (((a)->divisor == (priv)->pending_setup.divisor) \
140           && ((a)->control == (priv)->pending_setup.control) \
141           && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt))
142 
143 /* function prototypes */
144 static int oti6858_open(struct tty_struct *tty,
145                         struct usb_serial_port *port, struct file *filp);
146 static void oti6858_close(struct usb_serial_port *port);
147 static void oti6858_set_termios(struct tty_struct *tty,
148                         struct usb_serial_port *port, struct ktermios *old);
149 static void oti6858_init_termios(struct tty_struct *tty);
150 static int oti6858_ioctl(struct tty_struct *tty, struct file *file,
151                         unsigned int cmd, unsigned long arg);
152 static void oti6858_read_int_callback(struct urb *urb);
153 static void oti6858_read_bulk_callback(struct urb *urb);
154 static void oti6858_write_bulk_callback(struct urb *urb);
155 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
156                         const unsigned char *buf, int count);
157 static int oti6858_write_room(struct tty_struct *tty);
158 static int oti6858_chars_in_buffer(struct tty_struct *tty);
159 static int oti6858_tiocmget(struct tty_struct *tty, struct file *file);
160 static int oti6858_tiocmset(struct tty_struct *tty, struct file *file,
161                                 unsigned int set, unsigned int clear);
162 static int oti6858_startup(struct usb_serial *serial);
163 static void oti6858_release(struct usb_serial *serial);
164 
165 /* functions operating on buffers */
166 static struct oti6858_buf *oti6858_buf_alloc(unsigned int size);
167 static void oti6858_buf_free(struct oti6858_buf *pb);
168 static void oti6858_buf_clear(struct oti6858_buf *pb);
169 static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb);
170 static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb);
171 static unsigned int oti6858_buf_put(struct oti6858_buf *pb, const char *buf,
172                                         unsigned int count);
173 static unsigned int oti6858_buf_get(struct oti6858_buf *pb, char *buf,
174                                         unsigned int count);
175 
176 
177 /* device info */
178 static struct usb_serial_driver oti6858_device = {
179         .driver = {
180                 .owner =        THIS_MODULE,
181                 .name =         "oti6858",
182         },
183         .id_table =             id_table,
184         .num_ports =            1,
185         .open =                 oti6858_open,
186         .close =                oti6858_close,
187         .write =                oti6858_write,
188         .ioctl =                oti6858_ioctl,
189         .set_termios =          oti6858_set_termios,
190         .init_termios =         oti6858_init_termios,
191         .tiocmget =             oti6858_tiocmget,
192         .tiocmset =             oti6858_tiocmset,
193         .read_bulk_callback =   oti6858_read_bulk_callback,
194         .read_int_callback =    oti6858_read_int_callback,
195         .write_bulk_callback =  oti6858_write_bulk_callback,
196         .write_room =           oti6858_write_room,
197         .chars_in_buffer =      oti6858_chars_in_buffer,
198         .attach =               oti6858_startup,
199         .release =              oti6858_release,
200 };
201 
202 struct oti6858_private {
203         spinlock_t lock;
204 
205         struct oti6858_buf *buf;
206         struct oti6858_control_pkt status;
207 
208         struct {
209                 u8 read_urb_in_use;
210                 u8 write_urb_in_use;
211         } flags;
212         struct delayed_work delayed_write_work;
213 
214         struct {
215                 __le16 divisor;
216                 u8 frame_fmt;
217                 u8 control;
218         } pending_setup;
219         u8 transient;
220         u8 setup_done;
221         struct delayed_work delayed_setup_work;
222 
223         wait_queue_head_t intr_wait;
224         struct usb_serial_port *port;   /* USB port with which associated */
225 };
226 
227 static void setup_line(struct work_struct *work)
228 {
229         struct oti6858_private *priv = container_of(work,
230                         struct oti6858_private, delayed_setup_work.work);
231         struct usb_serial_port *port = priv->port;
232         struct oti6858_control_pkt *new_setup;
233         unsigned long flags;
234         int result;
235 
236         dbg("%s(port = %d)", __func__, port->number);
237 
238         new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
239         if (new_setup == NULL) {
240                 dev_err(&port->dev, "%s(): out of memory!\n", __func__);
241                 /* we will try again */
242                 schedule_delayed_work(&priv->delayed_setup_work,
243                                                 msecs_to_jiffies(2));
244                 return;
245         }
246 
247         result = usb_control_msg(port->serial->dev,
248                                 usb_rcvctrlpipe(port->serial->dev, 0),
249                                 OTI6858_REQ_T_GET_STATUS,
250                                 OTI6858_REQ_GET_STATUS,
251                                 0, 0,
252                                 new_setup, OTI6858_CTRL_PKT_SIZE,
253                                 100);
254 
255         if (result != OTI6858_CTRL_PKT_SIZE) {
256                 dev_err(&port->dev, "%s(): error reading status\n", __func__);
257                 kfree(new_setup);
258                 /* we will try again */
259                 schedule_delayed_work(&priv->delayed_setup_work,
260                                                         msecs_to_jiffies(2));
261                 return;
262         }
263 
264         spin_lock_irqsave(&priv->lock, flags);
265         if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
266                 new_setup->divisor = priv->pending_setup.divisor;
267                 new_setup->control = priv->pending_setup.control;
268                 new_setup->frame_fmt = priv->pending_setup.frame_fmt;
269 
270                 spin_unlock_irqrestore(&priv->lock, flags);
271                 result = usb_control_msg(port->serial->dev,
272                                         usb_sndctrlpipe(port->serial->dev, 0),
273                                         OTI6858_REQ_T_SET_LINE,
274                                         OTI6858_REQ_SET_LINE,
275                                         0, 0,
276                                         new_setup, OTI6858_CTRL_PKT_SIZE,
277                                         100);
278         } else {
279                 spin_unlock_irqrestore(&priv->lock, flags);
280                 result = 0;
281         }
282         kfree(new_setup);
283 
284         spin_lock_irqsave(&priv->lock, flags);
285         if (result != OTI6858_CTRL_PKT_SIZE)
286                 priv->transient = 0;
287         priv->setup_done = 1;
288         spin_unlock_irqrestore(&priv->lock, flags);
289 
290         dbg("%s(): submitting interrupt urb", __func__);
291         port->interrupt_in_urb->dev = port->serial->dev;
292         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
293         if (result != 0) {
294                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
295                                 " with error %d\n", __func__, result);
296         }
297 }
298 
299 void send_data(struct work_struct *work)
300 {
301         struct oti6858_private *priv = container_of(work,
302                         struct oti6858_private, delayed_write_work.work);
303         struct usb_serial_port *port = priv->port;
304         int count = 0, result;
305         unsigned long flags;
306         unsigned char allow;
307 
308         dbg("%s(port = %d)", __func__, port->number);
309 
310         spin_lock_irqsave(&priv->lock, flags);
311         if (priv->flags.write_urb_in_use) {
312                 spin_unlock_irqrestore(&priv->lock, flags);
313                 schedule_delayed_work(&priv->delayed_write_work,
314                                                 msecs_to_jiffies(2));
315                 return;
316         }
317         priv->flags.write_urb_in_use = 1;
318 
319         count = oti6858_buf_data_avail(priv->buf);
320         spin_unlock_irqrestore(&priv->lock, flags);
321         if (count > port->bulk_out_size)
322                 count = port->bulk_out_size;
323 
324         if (count != 0) {
325                 result = usb_control_msg(port->serial->dev,
326                                 usb_rcvctrlpipe(port->serial->dev, 0),
327                                 OTI6858_REQ_T_CHECK_TXBUFF,
328                                 OTI6858_REQ_CHECK_TXBUFF,
329                                 count, 0, &allow, 1, 100);
330                 if (result != 1 || allow != 0)
331                         count = 0;
332         }
333 
334         if (count == 0) {
335                 priv->flags.write_urb_in_use = 0;
336 
337                 dbg("%s(): submitting interrupt urb", __func__);
338                 port->interrupt_in_urb->dev = port->serial->dev;
339                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
340                 if (result != 0) {
341                         dev_err(&port->dev, "%s(): usb_submit_urb() failed"
342                                 " with error %d\n", __func__, result);
343                 }
344                 return;
345         }
346 
347         spin_lock_irqsave(&priv->lock, flags);
348         oti6858_buf_get(priv->buf, port->write_urb->transfer_buffer, count);
349         spin_unlock_irqrestore(&priv->lock, flags);
350 
351         port->write_urb->transfer_buffer_length = count;
352         port->write_urb->dev = port->serial->dev;
353         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
354         if (result != 0) {
355                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
356                                " with error %d\n", __func__, result);
357                 priv->flags.write_urb_in_use = 0;
358         }
359 
360         usb_serial_port_softint(port);
361 }
362 
363 static int oti6858_startup(struct usb_serial *serial)
364 {
365         struct usb_serial_port *port = serial->port[0];
366         struct oti6858_private *priv;
367         int i;
368 
369         for (i = 0; i < serial->num_ports; ++i) {
370                 priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
371                 if (!priv)
372                         break;
373                 priv->buf = oti6858_buf_alloc(PL2303_BUF_SIZE);
374                 if (priv->buf == NULL) {
375                         kfree(priv);
376                         break;
377                 }
378 
379                 spin_lock_init(&priv->lock);
380                 init_waitqueue_head(&priv->intr_wait);
381 /*              INIT_WORK(&priv->setup_work, setup_line, serial->port[i]); */
382 /*              INIT_WORK(&priv->write_work, send_data, serial->port[i]); */
383                 priv->port = port;
384                 INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
385                 INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);
386 
387                 usb_set_serial_port_data(serial->port[i], priv);
388         }
389         if (i == serial->num_ports)
390                 return 0;
391 
392         for (--i; i >= 0; --i) {
393                 priv = usb_get_serial_port_data(serial->port[i]);
394                 oti6858_buf_free(priv->buf);
395                 kfree(priv);
396                 usb_set_serial_port_data(serial->port[i], NULL);
397         }
398         return -ENOMEM;
399 }
400 
401 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
402                         const unsigned char *buf, int count)
403 {
404         struct oti6858_private *priv = usb_get_serial_port_data(port);
405         unsigned long flags;
406 
407         dbg("%s(port = %d, count = %d)", __func__, port->number, count);
408 
409         if (!count)
410                 return count;
411 
412         spin_lock_irqsave(&priv->lock, flags);
413         count = oti6858_buf_put(priv->buf, buf, count);
414         spin_unlock_irqrestore(&priv->lock, flags);
415 
416         return count;
417 }
418 
419 static int oti6858_write_room(struct tty_struct *tty)
420 {
421         struct usb_serial_port *port = tty->driver_data;
422         struct oti6858_private *priv = usb_get_serial_port_data(port);
423         int room = 0;
424         unsigned long flags;
425 
426         dbg("%s(port = %d)", __func__, port->number);
427 
428         spin_lock_irqsave(&priv->lock, flags);
429         room = oti6858_buf_space_avail(priv->buf);
430         spin_unlock_irqrestore(&priv->lock, flags);
431 
432         return room;
433 }
434 
435 static int oti6858_chars_in_buffer(struct tty_struct *tty)
436 {
437         struct usb_serial_port *port = tty->driver_data;
438         struct oti6858_private *priv = usb_get_serial_port_data(port);
439         int chars = 0;
440         unsigned long flags;
441 
442         dbg("%s(port = %d)", __func__, port->number);
443 
444         spin_lock_irqsave(&priv->lock, flags);
445         chars = oti6858_buf_data_avail(priv->buf);
446         spin_unlock_irqrestore(&priv->lock, flags);
447 
448         return chars;
449 }
450 
451 static void oti6858_init_termios(struct tty_struct *tty)
452 {
453         *(tty->termios) = tty_std_termios;
454         tty->termios->c_cflag = B38400 | CS8 | CREAD | HUPCL | CLOCAL;
455         tty->termios->c_ispeed = 38400;
456         tty->termios->c_ospeed = 38400;
457 }
458 
459 static void oti6858_set_termios(struct tty_struct *tty,
460                 struct usb_serial_port *port, struct ktermios *old_termios)
461 {
462         struct oti6858_private *priv = usb_get_serial_port_data(port);
463         unsigned long flags;
464         unsigned int cflag;
465         u8 frame_fmt, control;
466         __le16 divisor;
467         int br;
468 
469         dbg("%s(port = %d)", __func__, port->number);
470 
471         if (!tty) {
472                 dbg("%s(): no tty structures", __func__);
473                 return;
474         }
475 
476         cflag = tty->termios->c_cflag;
477 
478         spin_lock_irqsave(&priv->lock, flags);
479         divisor = priv->pending_setup.divisor;
480         frame_fmt = priv->pending_setup.frame_fmt;
481         control = priv->pending_setup.control;
482         spin_unlock_irqrestore(&priv->lock, flags);
483 
484         frame_fmt &= ~FMT_DATA_BITS_MASK;
485         switch (cflag & CSIZE) {
486         case CS5:
487                 frame_fmt |= FMT_DATA_BITS_5;
488                 break;
489         case CS6:
490                 frame_fmt |= FMT_DATA_BITS_6;
491                 break;
492         case CS7:
493                 frame_fmt |= FMT_DATA_BITS_7;
494                 break;
495         default:
496         case CS8:
497                 frame_fmt |= FMT_DATA_BITS_8;
498                 break;
499         }
500 
501         /* manufacturer claims that this device can work with baud rates
502          * up to 3 Mbps; I've tested it only on 115200 bps, so I can't
503          * guarantee that any other baud rate will work (especially
504          * the higher ones)
505          */
506         br = tty_get_baud_rate(tty);
507         if (br == 0) {
508                 divisor = 0;
509         } else {
510                 int real_br;
511                 int new_divisor;
512                 br = min(br, OTI6858_MAX_BAUD_RATE);
513 
514                 new_divisor = (96000000 + 8 * br) / (16 * br);
515                 real_br = 96000000 / (16 * new_divisor);
516                 divisor = cpu_to_le16(new_divisor);
517                 tty_encode_baud_rate(tty, real_br, real_br);
518         }
519 
520         frame_fmt &= ~FMT_STOP_BITS_MASK;
521         if ((cflag & CSTOPB) != 0)
522                 frame_fmt |= FMT_STOP_BITS_2;
523         else
524                 frame_fmt |= FMT_STOP_BITS_1;
525 
526         frame_fmt &= ~FMT_PARITY_MASK;
527         if ((cflag & PARENB) != 0) {
528                 if ((cflag & PARODD) != 0)
529                         frame_fmt |= FMT_PARITY_ODD;
530                 else
531                         frame_fmt |= FMT_PARITY_EVEN;
532         } else {
533                 frame_fmt |= FMT_PARITY_NONE;
534         }
535 
536         control &= ~CONTROL_MASK;
537         if ((cflag & CRTSCTS) != 0)
538                 control |= (CONTROL_DTR_HIGH | CONTROL_RTS_HIGH);
539 
540         /* change control lines if we are switching to or from B0 */
541         /* FIXME:
542         spin_lock_irqsave(&priv->lock, flags);
543         control = priv->line_control;
544         if ((cflag & CBAUD) == B0)
545                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
546         else
547                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
548         if (control != priv->line_control) {
549                 control = priv->line_control;
550                 spin_unlock_irqrestore(&priv->lock, flags);
551                 set_control_lines(serial->dev, control);
552         } else {
553                 spin_unlock_irqrestore(&priv->lock, flags);
554         }
555         */
556 
557         spin_lock_irqsave(&priv->lock, flags);
558         if (divisor != priv->pending_setup.divisor
559                         || control != priv->pending_setup.control
560                         || frame_fmt != priv->pending_setup.frame_fmt) {
561                 priv->pending_setup.divisor = divisor;
562                 priv->pending_setup.control = control;
563                 priv->pending_setup.frame_fmt = frame_fmt;
564         }
565         spin_unlock_irqrestore(&priv->lock, flags);
566 }
567 
568 static int oti6858_open(struct tty_struct *tty,
569                         struct usb_serial_port *port, struct file *filp)
570 {
571         struct oti6858_private *priv = usb_get_serial_port_data(port);
572         struct ktermios tmp_termios;
573         struct usb_serial *serial = port->serial;
574         struct oti6858_control_pkt *buf;
575         unsigned long flags;
576         int result;
577 
578         dbg("%s(port = %d)", __func__, port->number);
579 
580         usb_clear_halt(serial->dev, port->write_urb->pipe);
581         usb_clear_halt(serial->dev, port->read_urb->pipe);
582 
583         if (port->port.count != 1)
584                 return 0;
585 
586         buf = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL);
587         if (buf == NULL) {
588                 dev_err(&port->dev, "%s(): out of memory!\n", __func__);
589                 return -ENOMEM;
590         }
591 
592         result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
593                                 OTI6858_REQ_T_GET_STATUS,
594                                 OTI6858_REQ_GET_STATUS,
595                                 0, 0,
596                                 buf, OTI6858_CTRL_PKT_SIZE,
597                                 100);
598         if (result != OTI6858_CTRL_PKT_SIZE) {
599                 /* assume default (after power-on reset) values */
600                 buf->divisor = cpu_to_le16(0x009c);     /* 38400 bps */
601                 buf->frame_fmt = 0x03;  /* 8N1 */
602                 buf->something = 0x43;
603                 buf->control = 0x4c;    /* DTR, RTS */
604                 buf->tx_status = 0x00;
605                 buf->pin_state = 0x5b;  /* RTS, CTS, DSR, DTR, RI, DCD */
606                 buf->rx_bytes_avail = 0x00;
607         }
608 
609         spin_lock_irqsave(&priv->lock, flags);
610         memcpy(&priv->status, buf, OTI6858_CTRL_PKT_SIZE);
611         priv->pending_setup.divisor = buf->divisor;
612         priv->pending_setup.frame_fmt = buf->frame_fmt;
613         priv->pending_setup.control = buf->control;
614         spin_unlock_irqrestore(&priv->lock, flags);
615         kfree(buf);
616 
617         dbg("%s(): submitting interrupt urb", __func__);
618         port->interrupt_in_urb->dev = serial->dev;
619         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
620         if (result != 0) {
621                 dev_err(&port->dev, "%s(): usb_submit_urb() failed"
622                                " with error %d\n", __func__, result);
623                 oti6858_close(port);
624                 return -EPROTO;
625         }
626 
627         /* setup termios */
628         if (tty)
629                 oti6858_set_termios(tty, port, &tmp_termios);
630         port->port.drain_delay = 256;   /* FIXME: check the FIFO length */
631         return 0;
632 }
633 
634 static void oti6858_close(struct usb_serial_port *port)
635 {
636         struct oti6858_private *priv = usb_get_serial_port_data(port);
637         unsigned long flags;
638 
639         dbg("%s(port = %d)", __func__, port->number);
640 
641         spin_lock_irqsave(&priv->lock, flags);
642         /* clear out any remaining data in the buffer */
643         oti6858_buf_clear(priv->buf);
644         spin_unlock_irqrestore(&priv->lock, flags);
645 
646         dbg("%s(): after buf_clear()", __func__);
647 
648         /* cancel scheduled setup */
649         cancel_delayed_work(&priv->delayed_setup_work);
650         cancel_delayed_work(&priv->delayed_write_work);
651         flush_scheduled_work();
652 
653         /* shutdown our urbs */
654         dbg("%s(): shutting down urbs", __func__);
655         usb_kill_urb(port->write_urb);
656         usb_kill_urb(port->read_urb);
657         usb_kill_urb(port->interrupt_in_urb);
658 }
659 
660 static int oti6858_tiocmset(struct tty_struct *tty, struct file *file,
661                                 unsigned int set, unsigned int clear)
662 {
663         struct usb_serial_port *port = tty->driver_data;
664         struct oti6858_private *priv = usb_get_serial_port_data(port);
665         unsigned long flags;
666         u8 control;
667 
668         dbg("%s(port = %d, set = 0x%08x, clear = 0x%08x)",
669                                 __func__, port->number, set, clear);
670 
671         if (!usb_get_intfdata(port->serial->interface))
672                 return -ENODEV;
673 
674         /* FIXME: check if this is correct (active high/low) */
675         spin_lock_irqsave(&priv->lock, flags);
676         control = priv->pending_setup.control;
677         if ((set & TIOCM_RTS) != 0)
678                 control |= CONTROL_RTS_HIGH;
679         if ((set & TIOCM_DTR) != 0)
680                 control |= CONTROL_DTR_HIGH;
681         if ((clear & TIOCM_RTS) != 0)
682                 control &= ~CONTROL_RTS_HIGH;
683         if ((clear & TIOCM_DTR) != 0)
684                 control &= ~CONTROL_DTR_HIGH;
685 
686         if (control != priv->pending_setup.control)
687                 priv->pending_setup.control = control;
688 
689         spin_unlock_irqrestore(&priv->lock, flags);
690         return 0;
691 }
692 
693 static int oti6858_tiocmget(struct tty_struct *tty, struct file *file)
694 {
695         struct usb_serial_port *port = tty->driver_data;
696         struct oti6858_private *priv = usb_get_serial_port_data(port);
697         unsigned long flags;
698         unsigned pin_state;
699         unsigned result = 0;
700 
701         dbg("%s(port = %d)", __func__, port->number);
702 
703         if (!usb_get_intfdata(port->serial->interface))
704                 return -ENODEV;
705 
706         spin_lock_irqsave(&priv->lock, flags);
707         pin_state = priv->status.pin_state & PIN_MASK;
708         spin_unlock_irqrestore(&priv->lock, flags);
709 
710         /* FIXME: check if this is correct (active high/low) */
711         if ((pin_state & PIN_RTS) != 0)
712                 result |= TIOCM_RTS;
713         if ((pin_state & PIN_CTS) != 0)
714                 result |= TIOCM_CTS;
715         if ((pin_state & PIN_DSR) != 0)
716                 result |= TIOCM_DSR;
717         if ((pin_state & PIN_DTR) != 0)
718                 result |= TIOCM_DTR;
719         if ((pin_state & PIN_RI) != 0)
720                 result |= TIOCM_RI;
721         if ((pin_state & PIN_DCD) != 0)
722                 result |= TIOCM_CD;
723 
724         dbg("%s() = 0x%08x", __func__, result);
725 
726         return result;
727 }
728 
729 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
730 {
731         struct oti6858_private *priv = usb_get_serial_port_data(port);
732         unsigned long flags;
733         unsigned int prev, status;
734         unsigned int changed;
735 
736         spin_lock_irqsave(&priv->lock, flags);
737         prev = priv->status.pin_state;
738         spin_unlock_irqrestore(&priv->lock, flags);
739 
740         while (1) {
741                 wait_event_interruptible(priv->intr_wait,
742                                         priv->status.pin_state != prev);
743                 if (signal_pending(current))
744                         return -ERESTARTSYS;
745 
746                 spin_lock_irqsave(&priv->lock, flags);
747                 status = priv->status.pin_state & PIN_MASK;
748                 spin_unlock_irqrestore(&priv->lock, flags);
749 
750                 changed = prev ^ status;
751                 /* FIXME: check if this is correct (active high/low) */
752                 if (((arg & TIOCM_RNG) && (changed & PIN_RI)) ||
753                     ((arg & TIOCM_DSR) && (changed & PIN_DSR)) ||
754                     ((arg & TIOCM_CD)  && (changed & PIN_DCD)) ||
755                     ((arg & TIOCM_CTS) && (changed & PIN_CTS)))
756                         return 0;
757                 prev = status;
758         }
759 
760         /* NOTREACHED */
761         return 0;
762 }
763 
764 static int oti6858_ioctl(struct tty_struct *tty, struct file *file,
765                         unsigned int cmd, unsigned long arg)
766 {
767         struct usb_serial_port *port = tty->driver_data;
768 
769         dbg("%s(port = %d, cmd = 0x%04x, arg = 0x%08lx)",
770                                 __func__, port->number, cmd, arg);
771 
772         switch (cmd) {
773         case TIOCMIWAIT:
774                 dbg("%s(): TIOCMIWAIT", __func__);
775                 return wait_modem_info(port, arg);
776         default:
777                 dbg("%s(): 0x%04x not supported", __func__, cmd);
778                 break;
779         }
780         return -ENOIOCTLCMD;
781 }
782 
783 
784 static void oti6858_release(struct usb_serial *serial)
785 {
786         struct oti6858_private *priv;
787         int i;
788 
789         dbg("%s()", __func__);
790 
791         for (i = 0; i < serial->num_ports; ++i) {
792                 priv = usb_get_serial_port_data(serial->port[i]);
793                 if (priv) {
794                         oti6858_buf_free(priv->buf);
795                         kfree(priv);
796                 }
797         }
798 }
799 
800 static void oti6858_read_int_callback(struct urb *urb)
801 {
802         struct usb_serial_port *port =  urb->context;
803         struct oti6858_private *priv = usb_get_serial_port_data(port);
804         int transient = 0, can_recv = 0, resubmit = 1;
805         int status = urb->status;
806 
807         dbg("%s(port = %d, status = %d)",
808                                 __func__, port->number, status);
809 
810         switch (status) {
811         case 0:
812                 /* success */
813                 break;
814         case -ECONNRESET:
815         case -ENOENT:
816         case -ESHUTDOWN:
817                 /* this urb is terminated, clean up */
818                 dbg("%s(): urb shutting down with status: %d",
819                                         __func__, status);
820                 return;
821         default:
822                 dbg("%s(): nonzero urb status received: %d",
823                                         __func__, status);
824                 break;
825         }
826 
827         if (status == 0 && urb->actual_length == OTI6858_CTRL_PKT_SIZE) {
828                 struct oti6858_control_pkt *xs = urb->transfer_buffer;
829                 unsigned long flags;
830 
831                 spin_lock_irqsave(&priv->lock, flags);
832 
833                 if (!priv->transient) {
834                         if (!OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
835                                 if (xs->rx_bytes_avail == 0) {
836                                         priv->transient = 4;
837                                         priv->setup_done = 0;
838                                         resubmit = 0;
839                                         dbg("%s(): scheduling setup_line()",
840                                             __func__);
841                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
842                                 }
843                         }
844                 } else {
845                         if (OTI6858_CTRL_EQUALS_PENDING(xs, priv)) {
846                                 priv->transient = 0;
847                         } else if (!priv->setup_done) {
848                                 resubmit = 0;
849                         } else if (--priv->transient == 0) {
850                                 if (xs->rx_bytes_avail == 0) {
851                                         priv->transient = 4;
852                                         priv->setup_done = 0;
853                                         resubmit = 0;
854                                         dbg("%s(): scheduling setup_line()",
855                                             __func__);
856                                         schedule_delayed_work(&priv->delayed_setup_work, 0);
857                                 }
858                         }
859                 }
860 
861                 if (!priv->transient) {
862                         if (xs->pin_state != priv->status.pin_state)
863                                 wake_up_interruptible(&priv->intr_wait);
864                         memcpy(&priv->status, xs, OTI6858_CTRL_PKT_SIZE);
865                 }
866 
867                 if (!priv->transient && xs->rx_bytes_avail != 0) {
868                         can_recv = xs->rx_bytes_avail;
869                         priv->flags.read_urb_in_use = 1;
870                 }
871 
872                 transient = priv->transient;
873                 spin_unlock_irqrestore(&priv->lock, flags);
874         }
875 
876         if (can_recv) {
877                 int result;
878 
879                 port->read_urb->dev = port->serial->dev;
880                 result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
881                 if (result != 0) {
882                         priv->flags.read_urb_in_use = 0;
883                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
884                                         " error %d\n", __func__, result);
885                 } else {
886                         resubmit = 0;
887                 }
888         } else if (!transient) {
889                 unsigned long flags;
890 
891                 spin_lock_irqsave(&priv->lock, flags);
892                 if (priv->flags.write_urb_in_use == 0
893                                 && oti6858_buf_data_avail(priv->buf) != 0) {
894                         schedule_delayed_work(&priv->delayed_write_work, 0);
895                         resubmit = 0;
896                 }
897                 spin_unlock_irqrestore(&priv->lock, flags);
898         }
899 
900         if (resubmit) {
901                 int result;
902 
903 /*              dbg("%s(): submitting interrupt urb", __func__); */
904                 urb->dev = port->serial->dev;
905                 result = usb_submit_urb(urb, GFP_ATOMIC);
906                 if (result != 0) {
907                         dev_err(&urb->dev->dev,
908                                         "%s(): usb_submit_urb() failed with"
909                                         " error %d\n", __func__, result);
910                 }
911         }
912 }
913 
914 static void oti6858_read_bulk_callback(struct urb *urb)
915 {
916         struct usb_serial_port *port =  urb->context;
917         struct oti6858_private *priv = usb_get_serial_port_data(port);
918         struct tty_struct *tty;
919         unsigned char *data = urb->transfer_buffer;
920         unsigned long flags;
921         int status = urb->status;
922         int result;
923 
924         dbg("%s(port = %d, status = %d)",
925                                 __func__, port->number, status);
926 
927         spin_lock_irqsave(&priv->lock, flags);
928         priv->flags.read_urb_in_use = 0;
929         spin_unlock_irqrestore(&priv->lock, flags);
930 
931         if (status != 0) {
932                 if (!port->port.count) {
933                         dbg("%s(): port is closed, exiting", __func__);
934                         return;
935                 }
936                 /*
937                 if (status == -EPROTO) {
938                         * PL2303 mysteriously fails with -EPROTO reschedule
939                            the read *
940                         dbg("%s - caught -EPROTO, resubmitting the urb",
941                                                                 __func__);
942                         result = usb_submit_urb(urb, GFP_ATOMIC);
943                         if (result)
944                                 dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __func__, result);
945                         return;
946                 }
947                 */
948                 dbg("%s(): unable to handle the error, exiting", __func__);
949                 return;
950         }
951 
952         tty = tty_port_tty_get(&port->port);
953         if (tty != NULL && urb->actual_length > 0) {
954                 tty_insert_flip_string(tty, data, urb->actual_length);
955                 tty_flip_buffer_push(tty);
956         }
957         tty_kref_put(tty);
958 
959         /* schedule the interrupt urb if we are still open */
960         if (port->port.count != 0) {
961                 port->interrupt_in_urb->dev = port->serial->dev;
962                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
963                 if (result != 0) {
964                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
965                                         " error %d\n", __func__, result);
966                 }
967         }
968 }
969 
970 static void oti6858_write_bulk_callback(struct urb *urb)
971 {
972         struct usb_serial_port *port =  urb->context;
973         struct oti6858_private *priv = usb_get_serial_port_data(port);
974         int status = urb->status;
975         int result;
976 
977         dbg("%s(port = %d, status = %d)",
978                                 __func__, port->number, status);
979 
980         switch (status) {
981         case 0:
982                 /* success */
983                 break;
984         case -ECONNRESET:
985         case -ENOENT:
986         case -ESHUTDOWN:
987                 /* this urb is terminated, clean up */
988                 dbg("%s(): urb shutting down with status: %d",
989                                         __func__, status);
990                 priv->flags.write_urb_in_use = 0;
991                 return;
992         default:
993                 /* error in the urb, so we have to resubmit it */
994                 dbg("%s(): nonzero write bulk status received: %d",
995                                         __func__, status);
996                 dbg("%s(): overflow in write", __func__);
997 
998                 port->write_urb->transfer_buffer_length = 1;
999                 port->write_urb->dev = port->serial->dev;
1000                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1001                 if (result) {
1002                         dev_err(&port->dev, "%s(): usb_submit_urb() failed,"
1003                                         " error %d\n", __func__, result);
1004                 } else {
1005                         return;
1006                 }
1007         }
1008 
1009         priv->flags.write_urb_in_use = 0;
1010 
1011         /* schedule the interrupt urb if we are still open */
1012         port->interrupt_in_urb->dev = port->serial->dev;
1013         dbg("%s(): submitting interrupt urb", __func__);
1014         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1015         if (result != 0) {
1016                 dev_err(&port->dev, "%s(): failed submitting int urb,"
1017                                         " error %d\n", __func__, result);
1018         }
1019 }
1020 
1021 
1022 /*
1023  * oti6858_buf_alloc
1024  *
1025  * Allocate a circular buffer and all associated memory.
1026  */
1027 static struct oti6858_buf *oti6858_buf_alloc(unsigned int size)
1028 {
1029         struct oti6858_buf *pb;
1030 
1031         if (size == 0)
1032                 return NULL;
1033 
1034         pb = kmalloc(sizeof(struct oti6858_buf), GFP_KERNEL);
1035         if (pb == NULL)
1036                 return NULL;
1037 
1038         pb->buf_buf = kmalloc(size, GFP_KERNEL);
1039         if (pb->buf_buf == NULL) {
1040                 kfree(pb);
1041                 return NULL;
1042         }
1043 
1044         pb->buf_size = size;
1045         pb->buf_get = pb->buf_put = pb->buf_buf;
1046 
1047         return pb;
1048 }
1049 
1050 /*
1051  * oti6858_buf_free
1052  *
1053  * Free the buffer and all associated memory.
1054  */
1055 static void oti6858_buf_free(struct oti6858_buf *pb)
1056 {
1057         if (pb) {
1058                 kfree(pb->buf_buf);
1059                 kfree(pb);
1060         }
1061 }
1062 
1063 /*
1064  * oti6858_buf_clear
1065  *
1066  * Clear out all data in the circular buffer.
1067  */
1068 static void oti6858_buf_clear(struct oti6858_buf *pb)
1069 {
1070         if (pb != NULL) {
1071                 /* equivalent to a get of all data available */
1072                 pb->buf_get = pb->buf_put;
1073         }
1074 }
1075 
1076 /*
1077  * oti6858_buf_data_avail
1078  *
1079  * Return the number of bytes of data available in the circular
1080  * buffer.
1081  */
1082 static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb)
1083 {
1084         if (pb == NULL)
1085                 return 0;
1086         return (pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size;
1087 }
1088 
1089 /*
1090  * oti6858_buf_space_avail
1091  *
1092  * Return the number of bytes of space available in the circular
1093  * buffer.
1094  */
1095 static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb)
1096 {
1097         if (pb == NULL)
1098                 return 0;
1099         return (pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size;
1100 }
1101 
1102 /*
1103  * oti6858_buf_put
1104  *
1105  * Copy data data from a user buffer and put it into the circular buffer.
1106  * Restrict to the amount of space available.
1107  *
1108  * Return the number of bytes copied.
1109  */
1110 static unsigned int oti6858_buf_put(struct oti6858_buf *pb, const char *buf,
1111                                         unsigned int count)
1112 {
1113         unsigned int len;
1114 
1115         if (pb == NULL)
1116                 return 0;
1117 
1118         len  = oti6858_buf_space_avail(pb);
1119         if (count > len)
1120                 count = len;
1121 
1122         if (count == 0)
1123                 return 0;
1124 
1125         len = pb->buf_buf + pb->buf_size - pb->buf_put;
1126         if (count > len) {
1127                 memcpy(pb->buf_put, buf, len);
1128                 memcpy(pb->buf_buf, buf+len, count - len);
1129                 pb->buf_put = pb->buf_buf + count - len;
1130         } else {
1131                 memcpy(pb->buf_put, buf, count);
1132                 if (count < len)
1133                         pb->buf_put += count;
1134                 else /* count == len */
1135                         pb->buf_put = pb->buf_buf;
1136         }
1137 
1138         return count;
1139 }
1140 
1141 /*
1142  * oti6858_buf_get
1143  *
1144  * Get data from the circular buffer and copy to the given buffer.
1145  * Restrict to the amount of data available.
1146  *
1147  * Return the number of bytes copied.
1148  */
1149 static unsigned int oti6858_buf_get(struct oti6858_buf *pb, char *buf,
1150                                         unsigned int count)
1151 {
1152         unsigned int len;
1153 
1154         if (pb == NULL)
1155                 return 0;
1156 
1157         len = oti6858_buf_data_avail(pb);
1158         if (count > len)
1159                 count = len;
1160 
1161         if (count == 0)
1162                 return 0;
1163 
1164         len = pb->buf_buf + pb->buf_size - pb->buf_get;
1165         if (count > len) {
1166                 memcpy(buf, pb->buf_get, len);
1167                 memcpy(buf+len, pb->buf_buf, count - len);
1168                 pb->buf_get = pb->buf_buf + count - len;
1169         } else {
1170                 memcpy(buf, pb->buf_get, count);
1171                 if (count < len)
1172                         pb->buf_get += count;
1173                 else /* count == len */
1174                         pb->buf_get = pb->buf_buf;
1175         }
1176 
1177         return count;
1178 }
1179 
1180 /* module description and (de)initialization */
1181 
1182 static int __init oti6858_init(void)
1183 {
1184         int retval;
1185 
1186         retval = usb_serial_register(&oti6858_device);
1187         if (retval == 0) {
1188                 retval = usb_register(&oti6858_driver);
1189                 if (retval)
1190                         usb_serial_deregister(&oti6858_device);
1191         }
1192         return retval;
1193 }
1194 
1195 static void __exit oti6858_exit(void)
1196 {
1197         usb_deregister(&oti6858_driver);
1198         usb_serial_deregister(&oti6858_device);
1199 }
1200 
1201 module_init(oti6858_init);
1202 module_exit(oti6858_exit);
1203 
1204 MODULE_DESCRIPTION(OTI6858_DESCRIPTION);
1205 MODULE_AUTHOR(OTI6858_AUTHOR);
1206 MODULE_VERSION(OTI6858_VERSION);
1207 MODULE_LICENSE("GPL");
1208 
1209 module_param(debug, bool, S_IRUGO | S_IWUSR);
1210 MODULE_PARM_DESC(debug, "enable debug output");
1211 
1212 
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