Merge with kernel.org:/pub/scm/linux/kernel/git/gregkh/aoe-2.6.git/
[linux-2.6] / drivers / usb / serial / cypress_m8.c
1 /*
2  * USB Cypress M8 driver
3  *
4  *      Copyright (C) 2004
5  *          Lonnie Mendez (dignome@gmail.com) 
6  *      Copyright (C) 2003,2004
7  *          Neil Whelchel (koyama@firstlight.net)
8  *
9  *      This program is free software; you can redistribute it and/or modify
10  *      it under the terms of the GNU General Public License as published by
11  *      the Free Software Foundation; either version 2 of the License, or
12  *      (at your option) any later version.
13  *
14  * See Documentation/usb/usb-serial.txt for more information on using this driver
15  *
16  * See http://geocities.com/i0xox0i for information on this driver and the
17  * earthmate usb device.
18  *
19  *
20  *  Lonnie Mendez <dignome@gmail.com>
21  *  12-15-2004
22  *      Incorporated write buffering from pl2303 driver.  Fixed bug with line
23  *      handling so both lines are raised in cypress_open. (was dropping rts)
24  *      Various code cleanups made as well along with other misc bug fixes.
25  *
26  *  Lonnie Mendez <dignome@gmail.com>
27  *  04-10-2004
28  *      Driver modified to support dynamic line settings.  Various improvments
29  *      and features.
30  *
31  *  Neil Whelchel
32  *  10-2003
33  *      Driver first released.
34  *
35  *
36  * Long Term TODO:
37  *      Improve transfer speeds - both read/write are somewhat slow
38  *   at this point.
39  *      Improve debugging.  Show modem line status with debug output and
40  *   implement filtering for certain data as a module parameter.
41  */
42
43 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation for linux. */
44 /* Thanks to cypress for providing references for the hid reports. */
45 /* Thanks to Jiang Zhang for providing links and for general help. */
46 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */
47
48
49 #include <linux/config.h>
50 #include <linux/kernel.h>
51 #include <linux/errno.h>
52 #include <linux/init.h>
53 #include <linux/slab.h>
54 #include <linux/tty.h>
55 #include <linux/tty_driver.h>
56 #include <linux/tty_flip.h>
57 #include <linux/module.h>
58 #include <linux/moduleparam.h>
59 #include <linux/spinlock.h>
60 #include <linux/usb.h>
61 #include <linux/serial.h>
62 #include <linux/delay.h>
63 #include <asm/uaccess.h>
64
65 #include "usb-serial.h"
66 #include "cypress_m8.h"
67
68
69 #ifdef CONFIG_USB_SERIAL_DEBUG
70         static int debug = 1;
71 #else
72         static int debug;
73 #endif
74 static int stats;
75
76 /*
77  * Version Information
78  */
79 #define DRIVER_VERSION "v1.08"
80 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
81 #define DRIVER_DESC "Cypress USB to Serial Driver"
82
83 /* write buffer size defines */
84 #define CYPRESS_BUF_SIZE        1024
85 #define CYPRESS_CLOSING_WAIT    (30*HZ)
86
87 static struct usb_device_id id_table_earthmate [] = {
88         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
89         { }                                             /* Terminating entry */
90 };
91
92 static struct usb_device_id id_table_cyphidcomrs232 [] = {
93         { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
94         { }                                             /* Terminating entry */
95 };
96
97 static struct usb_device_id id_table_combined [] = {
98         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
99         { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
100         { }                                             /* Terminating entry */
101 };
102
103 MODULE_DEVICE_TABLE (usb, id_table_combined);
104
105 static struct usb_driver cypress_driver = {
106         .name =         "cypress",
107         .probe =        usb_serial_probe,
108         .disconnect =   usb_serial_disconnect,
109         .id_table =     id_table_combined,
110 };
111
112 struct cypress_private {
113         spinlock_t lock;                   /* private lock */
114         int chiptype;                      /* identifier of device, for quirks/etc */
115         int bytes_in;                      /* used for statistics */
116         int bytes_out;                     /* used for statistics */
117         int cmd_count;                     /* used for statistics */
118         int cmd_ctrl;                      /* always set this to 1 before issuing a command */
119         struct cypress_buf *buf;           /* write buffer */
120         int write_urb_in_use;              /* write urb in use indicator */
121         int termios_initialized;
122         __u8 line_control;                 /* holds dtr / rts value */
123         __u8 current_status;               /* received from last read - info on dsr,cts,cd,ri,etc */
124         __u8 current_config;               /* stores the current configuration byte */
125         __u8 rx_flags;                     /* throttling - used from whiteheat/ftdi_sio */
126         int baud_rate;                     /* stores current baud rate in integer form */
127         int cbr_mask;                      /* stores current baud rate in masked form */
128         int isthrottled;                   /* if throttled, discard reads */
129         wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
130         char prev_status, diff_status;     /* used for TIOCMIWAIT */
131         /* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
132         struct termios tmp_termios;        /* stores the old termios settings */
133         char calledfromopen;               /* used when issuing lines on open - fixes rts drop bug */
134 };
135
136 /* write buffer structure */
137 struct cypress_buf {
138         unsigned int    buf_size;
139         char            *buf_buf;
140         char            *buf_get;
141         char            *buf_put;
142 };
143
144 /* function prototypes for the Cypress USB to serial device */
145 static int  cypress_earthmate_startup   (struct usb_serial *serial);
146 static int  cypress_hidcom_startup      (struct usb_serial *serial);
147 static void cypress_shutdown            (struct usb_serial *serial);
148 static int  cypress_open                (struct usb_serial_port *port, struct file *filp);
149 static void cypress_close               (struct usb_serial_port *port, struct file *filp);
150 static int  cypress_write               (struct usb_serial_port *port, const unsigned char *buf, int count);
151 static void cypress_send                (struct usb_serial_port *port);
152 static int  cypress_write_room          (struct usb_serial_port *port);
153 static int  cypress_ioctl               (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
154 static void cypress_set_termios         (struct usb_serial_port *port, struct termios * old);
155 static int  cypress_tiocmget            (struct usb_serial_port *port, struct file *file);
156 static int  cypress_tiocmset            (struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
157 static int  cypress_chars_in_buffer     (struct usb_serial_port *port);
158 static void cypress_throttle            (struct usb_serial_port *port);
159 static void cypress_unthrottle          (struct usb_serial_port *port);
160 static void cypress_read_int_callback   (struct urb *urb, struct pt_regs *regs);
161 static void cypress_write_int_callback  (struct urb *urb, struct pt_regs *regs);
162 /* baud helper functions */
163 static int       mask_to_rate           (unsigned mask);
164 static unsigned  rate_to_mask           (int rate);
165 /* write buffer functions */
166 static struct cypress_buf *cypress_buf_alloc(unsigned int size);
167 static void               cypress_buf_free(struct cypress_buf *cb);
168 static void               cypress_buf_clear(struct cypress_buf *cb);
169 static unsigned int       cypress_buf_data_avail(struct cypress_buf *cb);
170 static unsigned int       cypress_buf_space_avail(struct cypress_buf *cb);
171 static unsigned int       cypress_buf_put(struct cypress_buf *cb, const char *buf,
172                                           unsigned int count);
173 static unsigned int       cypress_buf_get(struct cypress_buf *cb, char *buf,
174                                           unsigned int count);
175
176
177 static struct usb_serial_device_type cypress_earthmate_device = {
178         .owner =                        THIS_MODULE,
179         .name =                         "DeLorme Earthmate USB",
180         .short_name =                   "earthmate",
181         .id_table =                     id_table_earthmate,
182         .num_interrupt_in =             1,
183         .num_interrupt_out =            1,
184         .num_bulk_in =                  NUM_DONT_CARE,
185         .num_bulk_out =                 NUM_DONT_CARE,
186         .num_ports =                    1,
187         .attach =                       cypress_earthmate_startup,
188         .shutdown =                     cypress_shutdown,
189         .open =                         cypress_open,
190         .close =                        cypress_close,
191         .write =                        cypress_write,
192         .write_room =                   cypress_write_room,
193         .ioctl =                        cypress_ioctl,
194         .set_termios =                  cypress_set_termios,
195         .tiocmget =                     cypress_tiocmget,
196         .tiocmset =                     cypress_tiocmset,
197         .chars_in_buffer =              cypress_chars_in_buffer,
198         .throttle =                     cypress_throttle,
199         .unthrottle =                   cypress_unthrottle,
200         .read_int_callback =            cypress_read_int_callback,
201         .write_int_callback =           cypress_write_int_callback,
202 };
203
204 static struct usb_serial_device_type cypress_hidcom_device = {
205         .owner =                        THIS_MODULE,
206         .name =                         "HID->COM RS232 Adapter",
207         .short_name =                   "cyphidcom",
208         .id_table =                     id_table_cyphidcomrs232,
209         .num_interrupt_in =             1,
210         .num_interrupt_out =            1,
211         .num_bulk_in =                  NUM_DONT_CARE,
212         .num_bulk_out =                 NUM_DONT_CARE,
213         .num_ports =                    1,
214         .attach =                       cypress_hidcom_startup,
215         .shutdown =                     cypress_shutdown,
216         .open =                         cypress_open,
217         .close =                        cypress_close,
218         .write =                        cypress_write,
219         .write_room =                   cypress_write_room,
220         .ioctl =                        cypress_ioctl,
221         .set_termios =                  cypress_set_termios,
222         .tiocmget =                     cypress_tiocmget,
223         .tiocmset =                     cypress_tiocmset,
224         .chars_in_buffer =              cypress_chars_in_buffer,
225         .throttle =                     cypress_throttle,
226         .unthrottle =                   cypress_unthrottle,
227         .read_int_callback =            cypress_read_int_callback,
228         .write_int_callback =           cypress_write_int_callback,
229 };
230
231
232 /*****************************************************************************
233  * Cypress serial helper functions
234  *****************************************************************************/
235
236
237 /* This function can either set or retreive the current serial line settings */
238 static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, int data_bits, int stop_bits,
239                                    int parity_enable, int parity_type, int reset, int cypress_request_type)
240 {
241         int i, n_baud_rate = 0, retval = 0;
242         struct cypress_private *priv;
243         __u8 feature_buffer[5];
244         __u8 config;
245         unsigned long flags;
246
247         dbg("%s", __FUNCTION__);
248         
249         priv = usb_get_serial_port_data(port);
250
251         switch(cypress_request_type) {
252                 case CYPRESS_SET_CONFIG:
253
254                         /*
255                          * The general purpose firmware for the Cypress M8 allows for a maximum speed
256                          * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
257                          * firmware or not), if you need to modify this speed setting for your own
258                          * project please add your own chiptype and modify the code likewise.  The
259                          * Cypress HID->COM device will work successfully up to 115200bps.
260                          */
261                         if (baud_mask != priv->cbr_mask) {
262                                 dbg("%s - baud rate is changing", __FUNCTION__);
263                                 if ( priv->chiptype == CT_EARTHMATE ) {
264                                         /* 300 and 600 baud rates are supported under the generic firmware,
265                                          * but are not used with NMEA and SiRF protocols */
266                                         
267                                         if ( (baud_mask == B300) || (baud_mask == B600) ) {
268                                                 err("%s - failed setting baud rate, unsupported speed (default to 4800)",
269                                                     __FUNCTION__);
270                                                 n_baud_rate = 4800;
271                                         } else if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
272                                                 err("%s - failed setting baud rate, unsupported speed (default to 4800)",
273                                                     __FUNCTION__);
274                                                 n_baud_rate = 4800;
275                                         }
276                                 } else if (priv->chiptype == CT_CYPHIDCOM) {
277                                         if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
278                                                 err("%s - failed setting baud rate, unsupported speed (default to 4800)",
279                                                     __FUNCTION__);
280                                                 n_baud_rate = 4800;
281                                         }
282                                 } else if (priv->chiptype == CT_GENERIC) {
283                                         if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
284                                                 err("%s - failed setting baud rate, unsupported speed (default to 4800)",
285                                                     __FUNCTION__);
286                                                 n_baud_rate = 4800;
287                                         }
288                                 } else {
289                                         info("%s - please define your chiptype, using 4800bps default", __FUNCTION__);
290                                         n_baud_rate = 4800;
291                                 }
292                         } else {  /* baud rate not changing, keep the old */
293                                 n_baud_rate = priv->baud_rate;
294                         }
295                         dbg("%s - baud rate is being sent as %d", __FUNCTION__, n_baud_rate);
296
297                         
298                         /*
299                          * This algorithm accredited to Jiang Jay Zhang... thanks for all the help!
300                          */
301                         for (i = 0; i < 4; ++i) {
302                                 feature_buffer[i] = ( n_baud_rate >> (i*8) & 0xFF );
303                         }
304
305                         config = 0;                      // reset config byte
306                         config |= data_bits;             // assign data bits in 2 bit space ( max 3 )
307                         /* 1 bit gap */
308                         config |= (stop_bits << 3);      // assign stop bits in 1 bit space
309                         config |= (parity_enable << 4);  // assign parity flag in 1 bit space
310                         config |= (parity_type << 5);    // assign parity type in 1 bit space
311                         /* 1 bit gap */
312                         config |= (reset << 7);          // assign reset at end of byte, 1 bit space
313
314                         feature_buffer[4] = config;
315                                 
316                         dbg("%s - device is being sent this feature report:", __FUNCTION__);
317                         dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, feature_buffer[0], feature_buffer[1],
318                             feature_buffer[2], feature_buffer[3], feature_buffer[4]);
319                         
320                         retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
321                                                   HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
322                                                   0x0300, 0, feature_buffer, 5, 500);
323
324                         if (retval != 5)
325                                 err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
326                         else {
327                                 spin_lock_irqsave(&priv->lock, flags);
328                                 priv->baud_rate = n_baud_rate;
329                                 priv->cbr_mask = baud_mask;
330                                 priv->current_config = config;
331                                 ++priv->cmd_count;
332                                 spin_unlock_irqrestore(&priv->lock, flags);
333                         }
334                 break;
335                 case CYPRESS_GET_CONFIG:
336                         dbg("%s - retreiving serial line settings", __FUNCTION__);
337                         /* reset values in feature buffer */
338                         memset(feature_buffer, 0, 5);
339
340                         retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
341                                                   HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
342                                                   0x0300, 0, feature_buffer, 5, 500);
343                         if (retval != 5) {
344                                 err("%s - failed to retreive serial line settings - %d", __FUNCTION__, retval);
345                                 return retval;
346                         } else {
347                                 spin_lock_irqsave(&priv->lock, flags);
348                                 /* store the config in one byte, and later use bit masks to check values */
349                                 priv->current_config = feature_buffer[4];
350                                 /* reverse the process above to get the baud_mask value */
351                                 n_baud_rate = 0; // reset bits
352                                 for (i = 0; i < 4; ++i) {
353                                         n_baud_rate |= ( feature_buffer[i] << (i*8) );
354                                 }
355                                 
356                                 priv->baud_rate = n_baud_rate;
357                                 if ( (priv->cbr_mask = rate_to_mask(n_baud_rate)) == 0x40)
358                                         dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
359                                 ++priv->cmd_count;
360                                 spin_unlock_irqrestore(&priv->lock, flags);
361                         }
362                         break;
363                 default:
364                         err("%s - unsupported serial control command issued", __FUNCTION__);
365         }
366         return retval;
367 } /* cypress_serial_control */
368
369
370 /* given a baud mask, it will return speed on success */
371 static int mask_to_rate (unsigned mask)
372 {
373         int rate;
374
375         switch (mask) {
376                 case B0: rate = 0; break;
377                 case B300: rate = 300; break;
378                 case B600: rate = 600; break;
379                 case B1200: rate = 1200; break;
380                 case B2400: rate = 2400; break;
381                 case B4800: rate = 4800; break;
382                 case B9600: rate = 9600; break;
383                 case B19200: rate = 19200; break;
384                 case B38400: rate = 38400; break;
385                 case B57600: rate = 57600; break;
386                 case B115200: rate = 115200; break;
387                 default: rate = -1;
388         }
389
390         return rate;
391 }
392
393
394 static unsigned rate_to_mask (int rate)
395 {
396         unsigned mask;
397
398         switch (rate) {
399                 case 0: mask = B0; break;
400                 case 300: mask = B300; break;
401                 case 600: mask = B600; break;
402                 case 1200: mask = B1200; break;
403                 case 2400: mask = B2400; break;
404                 case 4800: mask = B4800; break;
405                 case 9600: mask = B9600; break;
406                 case 19200: mask = B19200; break;
407                 case 38400: mask = B38400; break;
408                 case 57600: mask = B57600; break;
409                 case 115200: mask = B115200; break;
410                 default: mask = 0x40;
411         }
412
413         return mask;
414 }
415 /*****************************************************************************
416  * Cypress serial driver functions
417  *****************************************************************************/
418
419
420 static int generic_startup (struct usb_serial *serial)
421 {
422         struct cypress_private *priv;
423
424         dbg("%s - port %d", __FUNCTION__, serial->port[0]->number);
425
426         priv = kmalloc(sizeof (struct cypress_private), GFP_KERNEL);
427         if (!priv)
428                 return -ENOMEM;
429
430         memset(priv, 0x00, sizeof (struct cypress_private));
431         spin_lock_init(&priv->lock);
432         priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
433         if (priv->buf == NULL) {
434                 kfree(priv);
435                 return -ENOMEM;
436         }
437         init_waitqueue_head(&priv->delta_msr_wait);
438         
439         usb_reset_configuration (serial->dev);
440         
441         priv->cmd_ctrl = 0;
442         priv->line_control = 0;
443         priv->termios_initialized = 0;
444         priv->calledfromopen = 0;
445         priv->rx_flags = 0;
446         usb_set_serial_port_data(serial->port[0], priv);
447         
448         return (0);     
449 }       
450
451
452 static int cypress_earthmate_startup (struct usb_serial *serial)
453 {
454         struct cypress_private *priv;
455
456         dbg("%s", __FUNCTION__);
457
458         if (generic_startup(serial)) {
459                 dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
460                 return 1;
461         }
462
463         priv = usb_get_serial_port_data(serial->port[0]);
464         priv->chiptype = CT_EARTHMATE;
465         
466         return (0);     
467 } /* cypress_earthmate_startup */
468
469
470 static int cypress_hidcom_startup (struct usb_serial *serial)
471 {
472         struct cypress_private *priv;
473
474         dbg("%s", __FUNCTION__);
475
476         if (generic_startup(serial)) {
477                 dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
478                 return 1;
479         }
480
481         priv = usb_get_serial_port_data(serial->port[0]);
482         priv->chiptype = CT_CYPHIDCOM;
483         
484         return (0);     
485 } /* cypress_hidcom_startup */
486
487
488 static void cypress_shutdown (struct usb_serial *serial)
489 {
490         struct cypress_private *priv;
491
492         dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);
493
494         /* all open ports are closed at this point */
495
496         priv = usb_get_serial_port_data(serial->port[0]);
497
498         if (priv) {
499                 cypress_buf_free(priv->buf);
500                 kfree(priv);
501                 usb_set_serial_port_data(serial->port[0], NULL);
502         }
503 }
504
505
506 static int cypress_open (struct usb_serial_port *port, struct file *filp)
507 {
508         struct cypress_private *priv = usb_get_serial_port_data(port);
509         struct usb_serial *serial = port->serial;
510         unsigned long flags;
511         int result = 0;
512
513         dbg("%s - port %d", __FUNCTION__, port->number);
514
515         /* clear halts before open */
516         usb_clear_halt(serial->dev, 0x00);
517         usb_clear_halt(serial->dev, 0x81);
518         usb_clear_halt(serial->dev, 0x02);
519
520         spin_lock_irqsave(&priv->lock, flags);
521         /* reset read/write statistics */
522         priv->bytes_in = 0;
523         priv->bytes_out = 0;
524         priv->cmd_count = 0;
525         priv->rx_flags = 0;
526         spin_unlock_irqrestore(&priv->lock, flags);
527
528         /* setting to zero could cause data loss */
529         port->tty->low_latency = 1;
530
531         /* raise both lines and set termios */
532         spin_lock_irqsave(&priv->lock, flags);
533         priv->line_control = CONTROL_DTR | CONTROL_RTS;
534         priv->calledfromopen = 1;
535         priv->cmd_ctrl = 1;
536         spin_unlock_irqrestore(&priv->lock, flags);
537         result = cypress_write(port, NULL, 0);
538
539         if (result) {
540                 dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
541                 return result;
542         } else
543                 dbg("%s - success setting the control lines", __FUNCTION__);    
544
545         cypress_set_termios(port, &priv->tmp_termios);
546
547         /* setup the port and start reading from the device */
548         if(!port->interrupt_in_urb){
549                 err("%s - interrupt_in_urb is empty!", __FUNCTION__);
550                 return(-1);
551         }
552
553         usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
554                 usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
555                 port->interrupt_in_urb->transfer_buffer, port->interrupt_in_urb->transfer_buffer_length,
556                 cypress_read_int_callback, port, port->interrupt_in_urb->interval);
557         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
558
559         if (result){
560                 dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
561         }
562
563         return result;
564 } /* cypress_open */
565
566
567 static void cypress_close(struct usb_serial_port *port, struct file * filp)
568 {
569         struct cypress_private *priv = usb_get_serial_port_data(port);
570         unsigned int c_cflag;
571         unsigned long flags;
572         int bps;
573         long timeout;
574         wait_queue_t wait;
575
576         dbg("%s - port %d", __FUNCTION__, port->number);
577
578         /* wait for data to drain from buffer */
579         spin_lock_irqsave(&priv->lock, flags);
580         timeout = CYPRESS_CLOSING_WAIT;
581         init_waitqueue_entry(&wait, current);
582         add_wait_queue(&port->tty->write_wait, &wait);
583         for (;;) {
584                 set_current_state(TASK_INTERRUPTIBLE);
585                 if (cypress_buf_data_avail(priv->buf) == 0
586                 || timeout == 0 || signal_pending(current)
587                 || !usb_get_intfdata(port->serial->interface))
588                         break;
589                 spin_unlock_irqrestore(&priv->lock, flags);
590                 timeout = schedule_timeout(timeout);
591                 spin_lock_irqsave(&priv->lock, flags);
592         }
593         set_current_state(TASK_RUNNING);
594         remove_wait_queue(&port->tty->write_wait, &wait);
595         /* clear out any remaining data in the buffer */
596         cypress_buf_clear(priv->buf);
597         spin_unlock_irqrestore(&priv->lock, flags);
598         
599         /* wait for characters to drain from device */
600         bps = tty_get_baud_rate(port->tty);
601         if (bps > 1200)
602                 timeout = max((HZ*2560)/bps,HZ/10);
603         else
604                 timeout = 2*HZ;
605         set_current_state(TASK_INTERRUPTIBLE);
606         schedule_timeout(timeout);
607
608         dbg("%s - stopping urbs", __FUNCTION__);
609         usb_kill_urb (port->interrupt_in_urb);
610         usb_kill_urb (port->interrupt_out_urb);
611
612         if (port->tty) {
613                 c_cflag = port->tty->termios->c_cflag;
614                 if (c_cflag & HUPCL) {
615                         /* drop dtr and rts */
616                         priv = usb_get_serial_port_data(port);
617                         spin_lock_irqsave(&priv->lock, flags);
618                         priv->line_control = 0;
619                         priv->cmd_ctrl = 1;
620                         spin_unlock_irqrestore(&priv->lock, flags);
621                         cypress_write(port, NULL, 0);
622                 }
623         }
624
625         if (stats)
626                 dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
627                           priv->bytes_in, priv->bytes_out, priv->cmd_count);
628 } /* cypress_close */
629
630
631 static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
632 {
633         struct cypress_private *priv = usb_get_serial_port_data(port);
634         unsigned long flags;
635         
636         dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
637
638         /* line control commands, which need to be executed immediately,
639            are not put into the buffer for obvious reasons.
640          */
641         if (priv->cmd_ctrl) {
642                 count = 0;
643                 goto finish;
644         }
645         
646         if (!count)
647                 return count;
648         
649         spin_lock_irqsave(&priv->lock, flags);
650         count = cypress_buf_put(priv->buf, buf, count);
651         spin_unlock_irqrestore(&priv->lock, flags);
652
653 finish:
654         cypress_send(port);
655
656         return count;
657 } /* cypress_write */
658
659
660 static void cypress_send(struct usb_serial_port *port)
661 {
662         int count = 0, result, offset, actual_size;
663         struct cypress_private *priv = usb_get_serial_port_data(port);
664         unsigned long flags;
665         
666         dbg("%s - port %d", __FUNCTION__, port->number);
667         dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
668         
669         spin_lock_irqsave(&priv->lock, flags);
670         if (priv->write_urb_in_use) {
671                 dbg("%s - can't write, urb in use", __FUNCTION__);
672                 spin_unlock_irqrestore(&priv->lock, flags);
673                 return;
674         }
675         spin_unlock_irqrestore(&priv->lock, flags);
676
677         /* clear buffer */
678         memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
679
680         spin_lock_irqsave(&priv->lock, flags);
681         switch (port->interrupt_out_size) {
682                 case 32:
683                         // this is for the CY7C64013...
684                         offset = 2;
685                         port->interrupt_out_buffer[0] = priv->line_control;
686                         break;
687                 case 8:
688                         // this is for the CY7C63743...
689                         offset = 1;
690                         port->interrupt_out_buffer[0] = priv->line_control;
691                         break;
692                 default:
693                         dbg("%s - wrong packet size", __FUNCTION__);
694                         spin_unlock_irqrestore(&priv->lock, flags);
695                         return;
696         }
697
698         if (priv->line_control & CONTROL_RESET)
699                 priv->line_control &= ~CONTROL_RESET;
700
701         if (priv->cmd_ctrl) {
702                 priv->cmd_count++;
703                 dbg("%s - line control command being issued", __FUNCTION__);
704                 spin_unlock_irqrestore(&priv->lock, flags);
705                 goto send;
706         } else
707                 spin_unlock_irqrestore(&priv->lock, flags);
708
709         count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
710                                 port->interrupt_out_size-offset);
711
712         if (count == 0) {
713                 return;
714         }
715
716         switch (port->interrupt_out_size) {
717                 case 32:
718                         port->interrupt_out_buffer[1] = count;
719                         break;
720                 case 8:
721                         port->interrupt_out_buffer[0] |= count;
722         }
723
724         dbg("%s - count is %d", __FUNCTION__, count);
725
726 send:
727         spin_lock_irqsave(&priv->lock, flags);
728         priv->write_urb_in_use = 1;
729         spin_unlock_irqrestore(&priv->lock, flags);
730
731         if (priv->cmd_ctrl)
732                 actual_size = 1;
733         else
734                 actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
735         
736         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, port->interrupt_out_size,
737                               port->interrupt_out_urb->transfer_buffer);
738
739         port->interrupt_out_urb->transfer_buffer_length = actual_size;
740         port->interrupt_out_urb->dev = port->serial->dev;
741         result = usb_submit_urb (port->interrupt_out_urb, GFP_ATOMIC);
742         if (result) {
743                 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
744                         result);
745                 priv->write_urb_in_use = 0;
746         }
747
748         spin_lock_irqsave(&priv->lock, flags);
749         if (priv->cmd_ctrl) {
750                 priv->cmd_ctrl = 0;
751         }
752         priv->bytes_out += count; /* do not count the line control and size bytes */
753         spin_unlock_irqrestore(&priv->lock, flags);
754
755         schedule_work(&port->work);
756 } /* cypress_send */
757
758
759 /* returns how much space is available in the soft buffer */
760 static int cypress_write_room(struct usb_serial_port *port)
761 {
762         struct cypress_private *priv = usb_get_serial_port_data(port);
763         int room = 0;
764         unsigned long flags;
765
766         dbg("%s - port %d", __FUNCTION__, port->number);
767
768         spin_lock_irqsave(&priv->lock, flags);
769         room = cypress_buf_space_avail(priv->buf);
770         spin_unlock_irqrestore(&priv->lock, flags);
771
772         dbg("%s - returns %d", __FUNCTION__, room);
773         return room;
774 }
775
776
777 static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
778 {
779         struct cypress_private *priv = usb_get_serial_port_data(port);
780         __u8 status, control;
781         unsigned int result = 0;
782         unsigned long flags;
783         
784         dbg("%s - port %d", __FUNCTION__, port->number);
785
786         spin_lock_irqsave(&priv->lock, flags);
787         control = priv->line_control;
788         status = priv->current_status;
789         spin_unlock_irqrestore(&priv->lock, flags);
790
791         result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
792                 | ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
793                 | ((status & UART_CTS)        ? TIOCM_CTS : 0)
794                 | ((status & UART_DSR)        ? TIOCM_DSR : 0)
795                 | ((status & UART_RI)         ? TIOCM_RI  : 0)
796                 | ((status & UART_CD)         ? TIOCM_CD  : 0);
797
798         dbg("%s - result = %x", __FUNCTION__, result);
799
800         return result;
801 }
802
803
804 static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
805                                unsigned int set, unsigned int clear)
806 {
807         struct cypress_private *priv = usb_get_serial_port_data(port);
808         unsigned long flags;
809         
810         dbg("%s - port %d", __FUNCTION__, port->number);
811
812         spin_lock_irqsave(&priv->lock, flags);
813         if (set & TIOCM_RTS)
814                 priv->line_control |= CONTROL_RTS;
815         if (set & TIOCM_DTR)
816                 priv->line_control |= CONTROL_DTR;
817         if (clear & TIOCM_RTS)
818                 priv->line_control &= ~CONTROL_RTS;
819         if (clear & TIOCM_DTR)
820                 priv->line_control &= ~CONTROL_DTR;
821         spin_unlock_irqrestore(&priv->lock, flags);
822
823         priv->cmd_ctrl = 1;
824         return cypress_write(port, NULL, 0);
825 }
826
827
828 static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
829 {
830         struct cypress_private *priv = usb_get_serial_port_data(port);
831
832         dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
833
834         switch (cmd) {
835                 case TIOCGSERIAL:
836                         if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
837                                 return -EFAULT;
838                         }
839                         return (0);
840                         break;
841                 case TIOCSSERIAL:
842                         if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
843                                 return -EFAULT;
844                         }
845                         /* here we need to call cypress_set_termios to invoke the new settings */
846                         cypress_set_termios(port, &priv->tmp_termios);
847                         return (0);
848                         break;
849                 /* these are called when setting baud rate from gpsd */
850                 case TCGETS:
851                         if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
852                                 return -EFAULT;
853                         }
854                         return (0);
855                         break;
856                 case TCSETS:
857                         if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
858                                 return -EFAULT;
859                         }
860                         /* here we need to call cypress_set_termios to invoke the new settings */
861                         cypress_set_termios(port, &priv->tmp_termios);
862                         return (0);
863                         break;
864                 /* This code comes from drivers/char/serial.c and ftdi_sio.c */
865                 case TIOCMIWAIT:
866                         while (priv != NULL) {
867                                 interruptible_sleep_on(&priv->delta_msr_wait);
868                                 /* see if a signal did it */
869                                 if (signal_pending(current))
870                                         return -ERESTARTSYS;
871                                 else {
872                                         char diff = priv->diff_status;
873
874                                         if (diff == 0) {
875                                                 return -EIO; /* no change => error */
876                                         }
877                                         
878                                         /* consume all events */
879                                         priv->diff_status = 0;
880
881                                         /* return 0 if caller wanted to know about these bits */
882                                         if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
883                                              ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
884                                              ((arg & TIOCM_CD) && (diff & UART_CD)) ||
885                                              ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
886                                                 return 0;
887                                         }
888                                         /* otherwise caller can't care less about what happened,
889                                          * and so we continue to wait for more events.
890                                          */
891                                 }
892                         }
893                         return 0;
894                         break;
895                 default:
896                         break;
897         }
898
899         dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);
900
901         return -ENOIOCTLCMD;
902 } /* cypress_ioctl */
903
904
905 static void cypress_set_termios (struct usb_serial_port *port, struct termios *old_termios)
906 {
907         struct cypress_private *priv = usb_get_serial_port_data(port);
908         struct tty_struct *tty;
909         int data_bits, stop_bits, parity_type, parity_enable;
910         unsigned cflag, iflag, baud_mask;
911         unsigned long flags;
912         __u8 oldlines;
913         int linechange;
914         
915         dbg("%s - port %d", __FUNCTION__, port->number);
916
917         tty = port->tty;
918         if ((!tty) || (!tty->termios)) {
919                 dbg("%s - no tty structures", __FUNCTION__);
920                 return;
921         }
922
923         spin_lock_irqsave(&priv->lock, flags);
924         if (!priv->termios_initialized) {
925                 if (priv->chiptype == CT_EARTHMATE) {
926                         *(tty->termios) = tty_std_termios;
927                         tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
928                 } else if (priv->chiptype == CT_CYPHIDCOM) {
929                         *(tty->termios) = tty_std_termios;
930                         tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
931                 }
932                 priv->termios_initialized = 1;
933         }
934         spin_unlock_irqrestore(&priv->lock, flags);
935
936         cflag = tty->termios->c_cflag;
937         iflag = tty->termios->c_iflag;
938
939         /* check if there are new settings */
940         if (old_termios) {
941                 if ((cflag != old_termios->c_cflag) ||
942                     (RELEVANT_IFLAG(iflag) != RELEVANT_IFLAG(old_termios->c_iflag))) {
943                         dbg("%s - attempting to set new termios settings", __FUNCTION__);
944                         /* should make a copy of this in case something goes wrong in the function, we can restore it */
945                         spin_lock_irqsave(&priv->lock, flags);
946                         priv->tmp_termios = *(tty->termios);
947                         spin_unlock_irqrestore(&priv->lock, flags); 
948                 } else {
949                         dbg("%s - nothing to do, exiting", __FUNCTION__);
950                         return;
951                 }
952         } else
953                 return;
954
955         /* set number of data bits, parity, stop bits */
956         /* when parity is disabled the parity type bit is ignored */
957
958         stop_bits = cflag & CSTOPB ? 1 : 0; /* 1 means 2 stop bits, 0 means 1 stop bit */
959         
960         if (cflag & PARENB) {
961                 parity_enable = 1;
962                 parity_type = cflag & PARODD ? 1 : 0; /* 1 means odd parity, 0 means even parity */
963         } else
964                 parity_enable = parity_type = 0;
965
966         if (cflag & CSIZE) {
967                 switch (cflag & CSIZE) {
968                         case CS5: data_bits = 0; break;
969                         case CS6: data_bits = 1; break;
970                         case CS7: data_bits = 2; break;
971                         case CS8: data_bits = 3; break;
972                         default: err("%s - CSIZE was set, but not CS5-CS8", __FUNCTION__); data_bits = 3;
973                 }
974         } else
975                 data_bits = 3;
976
977         spin_lock_irqsave(&priv->lock, flags);
978         oldlines = priv->line_control;
979         if ((cflag & CBAUD) == B0) {
980                 /* drop dtr and rts */
981                 dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
982                 baud_mask = B0;
983                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
984         } else {
985                 baud_mask = (cflag & CBAUD);
986                 switch(baud_mask) {
987                         case B300: dbg("%s - setting baud 300bps", __FUNCTION__); break;
988                         case B600: dbg("%s - setting baud 600bps", __FUNCTION__); break;
989                         case B1200: dbg("%s - setting baud 1200bps", __FUNCTION__); break;
990                         case B2400: dbg("%s - setting baud 2400bps", __FUNCTION__); break;
991                         case B4800: dbg("%s - setting baud 4800bps", __FUNCTION__); break;
992                         case B9600: dbg("%s - setting baud 9600bps", __FUNCTION__); break;
993                         case B19200: dbg("%s - setting baud 19200bps", __FUNCTION__); break;
994                         case B38400: dbg("%s - setting baud 38400bps", __FUNCTION__); break;
995                         case B57600: dbg("%s - setting baud 57600bps", __FUNCTION__); break;
996                         case B115200: dbg("%s - setting baud 115200bps", __FUNCTION__); break;
997                         default: dbg("%s - unknown masked baud rate", __FUNCTION__);
998                 }
999                 priv->line_control |= CONTROL_DTR;
1000                 
1001                 /* toggle CRTSCTS? - don't do this if being called from cypress_open */
1002                 if (!priv->calledfromopen) {
1003                         if (cflag & CRTSCTS)
1004                                 priv->line_control |= CONTROL_RTS;
1005                         else
1006                                 priv->line_control &= ~CONTROL_RTS;
1007                 }
1008         }
1009         spin_unlock_irqrestore(&priv->lock, flags);
1010         
1011         dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)", __FUNCTION__,
1012             stop_bits, parity_enable, parity_type, data_bits);
1013
1014         cypress_serial_control(port, baud_mask, data_bits, stop_bits, parity_enable,
1015                                parity_type, 0, CYPRESS_SET_CONFIG);
1016
1017         msleep(50);                     /* give some time between change and read (50ms) */
1018
1019         /* we perform a CYPRESS_GET_CONFIG so that the current settings are filled into the private structure
1020          * this should confirm that all is working if it returns what we just set */
1021         cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1022
1023         /* Here we can define custom tty settings for devices
1024          *
1025          * the main tty termios flag base comes from empeg.c
1026          */
1027
1028         spin_lock_irqsave(&priv->lock, flags);  
1029         if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
1030
1031                 dbg("Using custom termios settings for a baud rate of 4800bps.");
1032                 /* define custom termios settings for NMEA protocol */
1033
1034                 
1035                 tty->termios->c_iflag /* input modes - */
1036                         &= ~(IGNBRK             /* disable ignore break */
1037                         | BRKINT                /* disable break causes interrupt */
1038                         | PARMRK                /* disable mark parity errors */
1039                         | ISTRIP                /* disable clear high bit of input characters */
1040                         | INLCR                 /* disable translate NL to CR */
1041                         | IGNCR                 /* disable ignore CR */
1042                         | ICRNL                 /* disable translate CR to NL */
1043                         | IXON);                /* disable enable XON/XOFF flow control */
1044                 
1045                 tty->termios->c_oflag /* output modes */
1046                         &= ~OPOST;              /* disable postprocess output characters */
1047                 
1048                 tty->termios->c_lflag /* line discipline modes */
1049                         &= ~(ECHO               /* disable echo input characters */
1050                         | ECHONL                /* disable echo new line */
1051                         | ICANON                /* disable erase, kill, werase, and rprnt special characters */
1052                         | ISIG                  /* disable interrupt, quit, and suspend special characters */
1053                         | IEXTEN);              /* disable non-POSIX special characters */
1054
1055         } else if (priv->chiptype == CT_CYPHIDCOM) {
1056
1057                 // Software app handling it for device...       
1058
1059         }
1060         linechange = (priv->line_control != oldlines);
1061         spin_unlock_irqrestore(&priv->lock, flags);
1062
1063         /* if necessary, set lines */
1064         if (!priv->calledfromopen && linechange) {
1065                 priv->cmd_ctrl = 1;
1066                 cypress_write(port, NULL, 0);
1067         }
1068
1069         if (priv->calledfromopen)
1070                 priv->calledfromopen = 0;
1071         
1072 } /* cypress_set_termios */
1073
1074  
1075 /* returns amount of data still left in soft buffer */
1076 static int cypress_chars_in_buffer(struct usb_serial_port *port)
1077 {
1078         struct cypress_private *priv = usb_get_serial_port_data(port);
1079         int chars = 0;
1080         unsigned long flags;
1081
1082         dbg("%s - port %d", __FUNCTION__, port->number);
1083         
1084         spin_lock_irqsave(&priv->lock, flags);
1085         chars = cypress_buf_data_avail(priv->buf);
1086         spin_unlock_irqrestore(&priv->lock, flags);
1087
1088         dbg("%s - returns %d", __FUNCTION__, chars);
1089         return chars;
1090 }
1091
1092
1093 static void cypress_throttle (struct usb_serial_port *port)
1094 {
1095         struct cypress_private *priv = usb_get_serial_port_data(port);
1096         unsigned long flags;
1097
1098         dbg("%s - port %d", __FUNCTION__, port->number);
1099
1100         spin_lock_irqsave(&priv->lock, flags);
1101         priv->rx_flags = THROTTLED;
1102         spin_unlock_irqrestore(&priv->lock, flags);        
1103 }
1104
1105
1106 static void cypress_unthrottle (struct usb_serial_port *port)
1107 {
1108         struct cypress_private *priv = usb_get_serial_port_data(port);
1109         int actually_throttled, result;
1110         unsigned long flags;
1111
1112         dbg("%s - port %d", __FUNCTION__, port->number);
1113
1114         spin_lock_irqsave(&priv->lock, flags);
1115         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1116         priv->rx_flags = 0;
1117         spin_unlock_irqrestore(&priv->lock, flags);
1118
1119         if (actually_throttled) {
1120                 port->interrupt_in_urb->dev = port->serial->dev;
1121
1122                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1123                 if (result)
1124                         dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
1125         }
1126 }
1127
1128
1129 static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
1130 {
1131         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1132         struct cypress_private *priv = usb_get_serial_port_data(port);
1133         struct tty_struct *tty;
1134         unsigned char *data = urb->transfer_buffer;
1135         unsigned long flags;
1136         char tty_flag = TTY_NORMAL;     
1137         int havedata = 0;
1138         int bytes = 0;
1139         int result;
1140         int i = 0;
1141
1142         dbg("%s - port %d", __FUNCTION__, port->number);
1143
1144         if (urb->status) {
1145                 dbg("%s - nonzero read status received: %d", __FUNCTION__, urb->status);
1146                 return;
1147         }
1148
1149         spin_lock_irqsave(&priv->lock, flags);
1150         if (priv->rx_flags & THROTTLED) {
1151                 dbg("%s - now throttling", __FUNCTION__);
1152                 priv->rx_flags |= ACTUALLY_THROTTLED;
1153                 spin_unlock_irqrestore(&priv->lock, flags);
1154                 return;
1155         }
1156         spin_unlock_irqrestore(&priv->lock, flags);
1157
1158         tty = port->tty;
1159         if (!tty) {
1160                 dbg("%s - bad tty pointer - exiting", __FUNCTION__);
1161                 return;
1162         }
1163
1164         spin_lock_irqsave(&priv->lock, flags);
1165         switch(urb->actual_length) {
1166                 case 32:
1167                         // This is for the CY7C64013...
1168                         priv->current_status = data[0] & 0xF8;
1169                         bytes = data[1]+2;
1170                         i=2;
1171                         if (bytes > 2)
1172                                 havedata = 1;
1173                         break;
1174                 case 8:
1175                         // This is for the CY7C63743...
1176                         priv->current_status = data[0] & 0xF8;
1177                         bytes = (data[0] & 0x07)+1;
1178                         i=1;
1179                         if (bytes > 1)
1180                                 havedata = 1;
1181                         break;
1182                 default:
1183                         dbg("%s - wrong packet size - received %d bytes", __FUNCTION__, urb->actual_length);
1184                         spin_unlock_irqrestore(&priv->lock, flags);
1185                         goto continue_read;
1186         }
1187         spin_unlock_irqrestore(&priv->lock, flags);
1188
1189         usb_serial_debug_data (debug, &port->dev, __FUNCTION__, urb->actual_length, data);
1190
1191         spin_lock_irqsave(&priv->lock, flags);
1192         /* check to see if status has changed */
1193         if (priv != NULL) {
1194                 if (priv->current_status != priv->prev_status) {
1195                         priv->diff_status |= priv->current_status ^ priv->prev_status;
1196                         wake_up_interruptible(&priv->delta_msr_wait);
1197                         priv->prev_status = priv->current_status;
1198                 }
1199         }
1200         spin_unlock_irqrestore(&priv->lock, flags);     
1201
1202         /* hangup, as defined in acm.c... this might be a bad place for it though */
1203         if (tty && !(tty->termios->c_cflag & CLOCAL) && !(priv->current_status & UART_CD)) {
1204                 dbg("%s - calling hangup", __FUNCTION__);
1205                 tty_hangup(tty);
1206                 goto continue_read;
1207         }
1208
1209         /* There is one error bit... I'm assuming it is a parity error indicator
1210          * as the generic firmware will set this bit to 1 if a parity error occurs.
1211          * I can not find reference to any other error events.
1212          *
1213          */
1214         spin_lock_irqsave(&priv->lock, flags);
1215         if (priv->current_status & CYP_ERROR) {
1216                 spin_unlock_irqrestore(&priv->lock, flags);
1217                 tty_flag = TTY_PARITY;
1218                 dbg("%s - Parity Error detected", __FUNCTION__);
1219         } else
1220                 spin_unlock_irqrestore(&priv->lock, flags);
1221
1222         /* process read if there is data other than line status */
1223         if (tty && (bytes > i)) {
1224                 for (; i < bytes ; ++i) {
1225                         dbg("pushing byte number %d - %d - %c",i,data[i],data[i]);
1226                         if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
1227                                 tty_flip_buffer_push(tty);
1228                         }
1229                         tty_insert_flip_char(tty, data[i], tty_flag);
1230                 }
1231                 tty_flip_buffer_push(port->tty);
1232         }
1233
1234         spin_lock_irqsave(&priv->lock, flags);
1235         priv->bytes_in += bytes;  /* control and status byte(s) are also counted */
1236         spin_unlock_irqrestore(&priv->lock, flags);
1237
1238 continue_read:
1239         
1240         /* Continue trying to always read... unless the port has closed.  */
1241
1242         if (port->open_count > 0) {
1243         usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1244                 usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
1245                 port->interrupt_in_urb->transfer_buffer,
1246                 port->interrupt_in_urb->transfer_buffer_length,
1247                 cypress_read_int_callback, port,
1248                 port->interrupt_in_urb->interval);
1249         result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1250         if (result)
1251                 dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
1252         }
1253         
1254         return;
1255 } /* cypress_read_int_callback */
1256
1257
1258 static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
1259 {
1260         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1261         struct cypress_private *priv = usb_get_serial_port_data(port);
1262         int result;
1263
1264         dbg("%s - port %d", __FUNCTION__, port->number);
1265         
1266         switch (urb->status) {
1267                 case 0:
1268                         /* success */
1269                         break;
1270                 case -ECONNRESET:
1271                 case -ENOENT:
1272                 case -ESHUTDOWN:
1273                         /* this urb is terminated, clean up */
1274                         dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
1275                         priv->write_urb_in_use = 0;
1276                         return;
1277                 default:
1278                         /* error in the urb, so we have to resubmit it */
1279                         dbg("%s - Overflow in write", __FUNCTION__);
1280                         dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
1281                         port->interrupt_out_urb->transfer_buffer_length = 1;
1282                         port->interrupt_out_urb->dev = port->serial->dev;
1283                         result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1284                         if (result)
1285                                 dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
1286                                         __FUNCTION__, result);
1287                         else
1288                                 return;
1289         }
1290         
1291         priv->write_urb_in_use = 0;
1292         
1293         /* send any buffered data */
1294         cypress_send(port);
1295 }
1296
1297
1298 /*****************************************************************************
1299  * Write buffer functions - buffering code from pl2303 used
1300  *****************************************************************************/
1301
1302 /*
1303  * cypress_buf_alloc
1304  *
1305  * Allocate a circular buffer and all associated memory.
1306  */
1307
1308 static struct cypress_buf *cypress_buf_alloc(unsigned int size)
1309 {
1310
1311         struct cypress_buf *cb;
1312
1313
1314         if (size == 0)
1315                 return NULL;
1316
1317         cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
1318         if (cb == NULL)
1319                 return NULL;
1320
1321         cb->buf_buf = kmalloc(size, GFP_KERNEL);
1322         if (cb->buf_buf == NULL) {
1323                 kfree(cb);
1324                 return NULL;
1325         }
1326
1327         cb->buf_size = size;
1328         cb->buf_get = cb->buf_put = cb->buf_buf;
1329
1330         return cb;
1331
1332 }
1333
1334
1335 /*
1336  * cypress_buf_free
1337  *
1338  * Free the buffer and all associated memory.
1339  */
1340
1341 static void cypress_buf_free(struct cypress_buf *cb)
1342 {
1343         if (cb) {
1344                 kfree(cb->buf_buf);
1345                 kfree(cb);
1346         }
1347 }
1348
1349
1350 /*
1351  * cypress_buf_clear
1352  *
1353  * Clear out all data in the circular buffer.
1354  */
1355
1356 static void cypress_buf_clear(struct cypress_buf *cb)
1357 {
1358         if (cb != NULL)
1359                 cb->buf_get = cb->buf_put;
1360                 /* equivalent to a get of all data available */
1361 }
1362
1363
1364 /*
1365  * cypress_buf_data_avail
1366  *
1367  * Return the number of bytes of data available in the circular
1368  * buffer.
1369  */
1370
1371 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
1372 {
1373         if (cb != NULL)
1374                 return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
1375         else
1376                 return 0;
1377 }
1378
1379
1380 /*
1381  * cypress_buf_space_avail
1382  *
1383  * Return the number of bytes of space available in the circular
1384  * buffer.
1385  */
1386
1387 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
1388 {
1389         if (cb != NULL)
1390                 return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
1391         else
1392                 return 0;
1393 }
1394
1395
1396 /*
1397  * cypress_buf_put
1398  *
1399  * Copy data data from a user buffer and put it into the circular buffer.
1400  * Restrict to the amount of space available.
1401  *
1402  * Return the number of bytes copied.
1403  */
1404
1405 static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
1406         unsigned int count)
1407 {
1408
1409         unsigned int len;
1410
1411
1412         if (cb == NULL)
1413                 return 0;
1414
1415         len  = cypress_buf_space_avail(cb);
1416         if (count > len)
1417                 count = len;
1418
1419         if (count == 0)
1420                 return 0;
1421
1422         len = cb->buf_buf + cb->buf_size - cb->buf_put;
1423         if (count > len) {
1424                 memcpy(cb->buf_put, buf, len);
1425                 memcpy(cb->buf_buf, buf+len, count - len);
1426                 cb->buf_put = cb->buf_buf + count - len;
1427         } else {
1428                 memcpy(cb->buf_put, buf, count);
1429                 if (count < len)
1430                         cb->buf_put += count;
1431                 else /* count == len */
1432                         cb->buf_put = cb->buf_buf;
1433         }
1434
1435         return count;
1436
1437 }
1438
1439
1440 /*
1441  * cypress_buf_get
1442  *
1443  * Get data from the circular buffer and copy to the given buffer.
1444  * Restrict to the amount of data available.
1445  *
1446  * Return the number of bytes copied.
1447  */
1448
1449 static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
1450         unsigned int count)
1451 {
1452
1453         unsigned int len;
1454
1455
1456         if (cb == NULL)
1457                 return 0;
1458
1459         len = cypress_buf_data_avail(cb);
1460         if (count > len)
1461                 count = len;
1462
1463         if (count == 0)
1464                 return 0;
1465
1466         len = cb->buf_buf + cb->buf_size - cb->buf_get;
1467         if (count > len) {
1468                 memcpy(buf, cb->buf_get, len);
1469                 memcpy(buf+len, cb->buf_buf, count - len);
1470                 cb->buf_get = cb->buf_buf + count - len;
1471         } else {
1472                 memcpy(buf, cb->buf_get, count);
1473                 if (count < len)
1474                         cb->buf_get += count;
1475                 else /* count == len */
1476                         cb->buf_get = cb->buf_buf;
1477         }
1478
1479         return count;
1480
1481 }
1482
1483 /*****************************************************************************
1484  * Module functions
1485  *****************************************************************************/
1486
1487 static int __init cypress_init(void)
1488 {
1489         int retval;
1490         
1491         dbg("%s", __FUNCTION__);
1492         
1493         retval = usb_serial_register(&cypress_earthmate_device);
1494         if (retval)
1495                 goto failed_em_register;
1496         retval = usb_serial_register(&cypress_hidcom_device);
1497         if (retval)
1498                 goto failed_hidcom_register;
1499         retval = usb_register(&cypress_driver);
1500         if (retval)
1501                 goto failed_usb_register;
1502
1503         info(DRIVER_DESC " " DRIVER_VERSION);
1504         return 0;
1505 failed_usb_register:
1506         usb_deregister(&cypress_driver);
1507 failed_hidcom_register:
1508         usb_serial_deregister(&cypress_hidcom_device);
1509 failed_em_register:
1510         usb_serial_deregister(&cypress_earthmate_device);
1511
1512         return retval;
1513 }
1514
1515
1516 static void __exit cypress_exit (void)
1517 {
1518         dbg("%s", __FUNCTION__);
1519
1520         usb_deregister (&cypress_driver);
1521         usb_serial_deregister (&cypress_earthmate_device);
1522         usb_serial_deregister (&cypress_hidcom_device);
1523 }
1524
1525
1526 module_init(cypress_init);
1527 module_exit(cypress_exit);
1528
1529 MODULE_AUTHOR( DRIVER_AUTHOR );
1530 MODULE_DESCRIPTION( DRIVER_DESC );
1531 MODULE_VERSION( DRIVER_VERSION );
1532 MODULE_LICENSE("GPL");
1533
1534 module_param(debug, bool, S_IRUGO | S_IWUSR);
1535 MODULE_PARM_DESC(debug, "Debug enabled or not");
1536 module_param(stats, bool, S_IRUGO | S_IWUSR);
1537 MODULE_PARM_DESC(stats, "Enable statistics or not");