drivers/usb/serial/cypress_m8.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * USB Cypress M8 driver
   4  *
   5  *      Copyright (C) 2004
   6  *          Lonnie Mendez (dignome@gmail.com)
   7  *      Copyright (C) 2003,2004
   8  *          Neil Whelchel (koyama@firstlight.net)
   9  *
  10  * See Documentation/usb/usb-serial.rst for more information on using this
  11  * driver
  12  *
  13  * See http://geocities.com/i0xox0i for information on this driver and the
  14  * earthmate usb device.
  15  */
  16
  17 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation
  18    for linux. */
  19 /* Thanks to cypress for providing references for the hid reports. */
  20 /* Thanks to Jiang Zhang for providing links and for general help. */
  21 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
  22
  23
  24 #include <linux/kernel.h>
  25 #include <linux/errno.h>
  26 #include <linux/slab.h>
  27 #include <linux/tty.h>
  28 #include <linux/tty_driver.h>
  29 #include <linux/tty_flip.h>
  30 #include <linux/module.h>
  31 #include <linux/moduleparam.h>
  32 #include <linux/spinlock.h>
  33 #include <linux/usb.h>
  34 #include <linux/usb/serial.h>
  35 #include <linux/serial.h>
  36 #include <linux/kfifo.h>
  37 #include <linux/delay.h>
  38 #include <linux/uaccess.h>
  39 #include <asm/unaligned.h>
  40
  41 #include "cypress_m8.h"
  42
  43
  44 static bool stats;
  45 static int interval;
  46 static bool unstable_bauds;
  47
  48 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
  49 #define DRIVER_DESC "Cypress USB to Serial Driver"
  50
  51 /* write buffer size defines */
  52 #define CYPRESS_BUF_SIZE        1024
  53
  54 static const struct usb_device_id id_table_earthmate[] = {
  55         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
  56         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
  57         { }                                             /* Terminating entry */
  58 };
  59
  60 static const struct usb_device_id id_table_cyphidcomrs232[] = {
  61         { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
  62         { USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
  63         { USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
  64         { USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
  65         { }                                             /* Terminating entry */
  66 };
  67
  68 static const struct usb_device_id id_table_nokiaca42v2[] = {
  69         { USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
  70         { }                                             /* Terminating entry */
  71 };
  72
  73 static const struct usb_device_id id_table_combined[] = {
  74         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
  75         { USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
  76         { USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
  77         { USB_DEVICE(VENDOR_ID_SAI, PRODUCT_ID_CYPHIDCOM) },
  78         { USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
  79         { USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
  80         { USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
  81         { }                                             /* Terminating entry */
  82 };
  83
  84 MODULE_DEVICE_TABLE(usb, id_table_combined);
  85
  86 enum packet_format {
  87         packet_format_1,  /* b0:status, b1:payload count */
  88         packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
  89 };
  90
  91 struct cypress_private {
  92         spinlock_t lock;                   /* private lock */
  93         int chiptype;                      /* identifier of device, for quirks/etc */
  94         int bytes_in;                      /* used for statistics */
  95         int bytes_out;                     /* used for statistics */
  96         int cmd_count;                     /* used for statistics */
  97         int cmd_ctrl;                      /* always set this to 1 before issuing a command */
  98         struct kfifo write_fifo;           /* write fifo */
  99         int write_urb_in_use;              /* write urb in use indicator */
 100         int write_urb_interval;            /* interval to use for write urb */
 101         int read_urb_interval;             /* interval to use for read urb */
 102         int comm_is_ok;                    /* true if communication is (still) ok */
 103         __u8 line_control;                 /* holds dtr / rts value */
 104         __u8 current_status;               /* received from last read - info on dsr,cts,cd,ri,etc */
 105         __u8 current_config;               /* stores the current configuration byte */
 106         __u8 rx_flags;                     /* throttling - used from whiteheat/ftdi_sio */
 107         enum packet_format pkt_fmt;        /* format to use for packet send / receive */
 108         int get_cfg_unsafe;                /* If true, the CYPRESS_GET_CONFIG is unsafe */
 109         int baud_rate;                     /* stores current baud rate in
 110                                               integer form */
 111         char prev_status;                  /* used for TIOCMIWAIT */
 112 };
 113
 114 /* function prototypes for the Cypress USB to serial device */
 115 static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
 116 static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
 117 static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
 118 static void cypress_port_remove(struct usb_serial_port *port);
 119 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
 120 static void cypress_close(struct usb_serial_port *port);
 121 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
 122 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
 123                         const unsigned char *buf, int count);
 124 static void cypress_send(struct usb_serial_port *port);
 125 static unsigned int cypress_write_room(struct tty_struct *tty);
 126 static void cypress_earthmate_init_termios(struct tty_struct *tty);
 127 static void cypress_set_termios(struct tty_struct *tty,
 128                                 struct usb_serial_port *port,
 129                                 const struct ktermios *old_termios);
 130 static int  cypress_tiocmget(struct tty_struct *tty);
 131 static int  cypress_tiocmset(struct tty_struct *tty,
 132                         unsigned int set, unsigned int clear);
 133 static unsigned int cypress_chars_in_buffer(struct tty_struct *tty);
 134 static void cypress_throttle(struct tty_struct *tty);
 135 static void cypress_unthrottle(struct tty_struct *tty);
 136 static void cypress_set_dead(struct usb_serial_port *port);
 137 static void cypress_read_int_callback(struct urb *urb);
 138 static void cypress_write_int_callback(struct urb *urb);
 139
 140 static struct usb_serial_driver cypress_earthmate_device = {
 141         .driver = {
 142                 .owner =                THIS_MODULE,
 143                 .name =                 "earthmate",
 144         },
 145         .description =                  "DeLorme Earthmate USB",
 146         .id_table =                     id_table_earthmate,
 147         .num_ports =                    1,
 148         .port_probe =                   cypress_earthmate_port_probe,
 149         .port_remove =                  cypress_port_remove,
 150         .open =                         cypress_open,
 151         .close =                        cypress_close,
 152         .dtr_rts =                      cypress_dtr_rts,
 153         .write =                        cypress_write,
 154         .write_room =                   cypress_write_room,
 155         .init_termios =                 cypress_earthmate_init_termios,
 156         .set_termios =                  cypress_set_termios,
 157         .tiocmget =                     cypress_tiocmget,
 158         .tiocmset =                     cypress_tiocmset,
 159         .tiocmiwait =                   usb_serial_generic_tiocmiwait,
 160         .chars_in_buffer =              cypress_chars_in_buffer,
 161         .throttle =                     cypress_throttle,
 162         .unthrottle =                   cypress_unthrottle,
 163         .read_int_callback =            cypress_read_int_callback,
 164         .write_int_callback =           cypress_write_int_callback,
 165 };
 166
 167 static struct usb_serial_driver cypress_hidcom_device = {
 168         .driver = {
 169                 .owner =                THIS_MODULE,
 170                 .name =                 "cyphidcom",
 171         },
 172         .description =                  "HID->COM RS232 Adapter",
 173         .id_table =                     id_table_cyphidcomrs232,
 174         .num_ports =                    1,
 175         .port_probe =                   cypress_hidcom_port_probe,
 176         .port_remove =                  cypress_port_remove,
 177         .open =                         cypress_open,
 178         .close =                        cypress_close,
 179         .dtr_rts =                      cypress_dtr_rts,
 180         .write =                        cypress_write,
 181         .write_room =                   cypress_write_room,
 182         .set_termios =                  cypress_set_termios,
 183         .tiocmget =                     cypress_tiocmget,
 184         .tiocmset =                     cypress_tiocmset,
 185         .tiocmiwait =                   usb_serial_generic_tiocmiwait,
 186         .chars_in_buffer =              cypress_chars_in_buffer,
 187         .throttle =                     cypress_throttle,
 188         .unthrottle =                   cypress_unthrottle,
 189         .read_int_callback =            cypress_read_int_callback,
 190         .write_int_callback =           cypress_write_int_callback,
 191 };
 192
 193 static struct usb_serial_driver cypress_ca42v2_device = {
 194         .driver = {
 195                 .owner =                THIS_MODULE,
 196                 .name =                 "nokiaca42v2",
 197         },
 198         .description =                  "Nokia CA-42 V2 Adapter",
 199         .id_table =                     id_table_nokiaca42v2,
 200         .num_ports =                    1,
 201         .port_probe =                   cypress_ca42v2_port_probe,
 202         .port_remove =                  cypress_port_remove,
 203         .open =                         cypress_open,
 204         .close =                        cypress_close,
 205         .dtr_rts =                      cypress_dtr_rts,
 206         .write =                        cypress_write,
 207         .write_room =                   cypress_write_room,
 208         .set_termios =                  cypress_set_termios,
 209         .tiocmget =                     cypress_tiocmget,
 210         .tiocmset =                     cypress_tiocmset,
 211         .tiocmiwait =                   usb_serial_generic_tiocmiwait,
 212         .chars_in_buffer =              cypress_chars_in_buffer,
 213         .throttle =                     cypress_throttle,
 214         .unthrottle =                   cypress_unthrottle,
 215         .read_int_callback =            cypress_read_int_callback,
 216         .write_int_callback =           cypress_write_int_callback,
 217 };
 218
 219 static struct usb_serial_driver * const serial_drivers[] = {
 220         &cypress_earthmate_device, &cypress_hidcom_device,
 221         &cypress_ca42v2_device, NULL
 222 };
 223
 224 /*****************************************************************************
 225  * Cypress serial helper functions
 226  *****************************************************************************/
 227
 228 /* FRWD Dongle hidcom needs to skip reset and speed checks */
 229 static inline bool is_frwd(struct usb_device *dev)
 230 {
 231         return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
 232                 (le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
 233 }
 234
 235 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
 236 {
 237         struct cypress_private *priv;
 238         priv = usb_get_serial_port_data(port);
 239
 240         if (unstable_bauds)
 241                 return new_rate;
 242
 243         /* FRWD Dongle uses 115200 bps */
 244         if (is_frwd(port->serial->dev))
 245                 return new_rate;
 246
 247         /*
 248          * The general purpose firmware for the Cypress M8 allows for
 249          * a maximum speed of 57600bps (I have no idea whether DeLorme
 250          * chose to use the general purpose firmware or not), if you
 251          * need to modify this speed setting for your own project
 252          * please add your own chiptype and modify the code likewise.
 253          * The Cypress HID->COM device will work successfully up to
 254          * 115200bps (but the actual throughput is around 3kBps).
 255          */
 256         if (port->serial->dev->speed == USB_SPEED_LOW) {
 257                 /*
 258                  * Mike Isely <isely@pobox.com> 2-Feb-2008: The
 259                  * Cypress app note that describes this mechanism
 260                  * states that the low-speed part can't handle more
 261                  * than 800 bytes/sec, in which case 4800 baud is the
 262                  * safest speed for a part like that.
 263                  */
 264                 if (new_rate > 4800) {
 265                         dev_dbg(&port->dev,
 266                                 "%s - failed setting baud rate, device incapable speed %d\n",
 267                                 __func__, new_rate);
 268                         return -1;
 269                 }
 270         }
 271         switch (priv->chiptype) {
 272         case CT_EARTHMATE:
 273                 if (new_rate <= 600) {
 274                         /* 300 and 600 baud rates are supported under
 275                          * the generic firmware, but are not used with
 276                          * NMEA and SiRF protocols */
 277                         dev_dbg(&port->dev,
 278                                 "%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS\n",
 279                                 __func__, new_rate);
 280                         return -1;
 281                 }
 282                 break;
 283         default:
 284                 break;
 285         }
 286         return new_rate;
 287 }
 288
 289
 290 /* This function can either set or retrieve the current serial line settings */
 291 static int cypress_serial_control(struct tty_struct *tty,
 292         struct usb_serial_port *port, speed_t baud_rate, int data_bits,
 293         int stop_bits, int parity_enable, int parity_type, int reset,
 294         int cypress_request_type)
 295 {
 296         int new_baudrate = 0, retval = 0, tries = 0;
 297         struct cypress_private *priv;
 298         struct device *dev = &port->dev;
 299         u8 *feature_buffer;
 300         const unsigned int feature_len = 5;
 301         unsigned long flags;
 302
 303         priv = usb_get_serial_port_data(port);
 304
 305         if (!priv->comm_is_ok)
 306                 return -ENODEV;
 307
 308         feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
 309         if (!feature_buffer)
 310                 return -ENOMEM;
 311
 312         switch (cypress_request_type) {
 313         case CYPRESS_SET_CONFIG:
 314                 /* 0 means 'Hang up' so doesn't change the true bit rate */
 315                 new_baudrate = priv->baud_rate;
 316                 if (baud_rate && baud_rate != priv->baud_rate) {
 317                         dev_dbg(dev, "%s - baud rate is changing\n", __func__);
 318                         retval = analyze_baud_rate(port, baud_rate);
 319                         if (retval >= 0) {
 320                                 new_baudrate = retval;
 321                                 dev_dbg(dev, "%s - New baud rate set to %d\n",
 322                                         __func__, new_baudrate);
 323                         }
 324                 }
 325                 dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
 326                         new_baudrate);
 327
 328                 /* fill the feature_buffer with new configuration */
 329                 put_unaligned_le32(new_baudrate, feature_buffer);
 330                 feature_buffer[4] |= data_bits - 5;   /* assign data bits in 2 bit space ( max 3 ) */
 331                 /* 1 bit gap */
 332                 feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
 333                 feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
 334                 feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
 335                 /* 1 bit gap */
 336                 feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
 337
 338                 dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
 339                 dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
 340                         feature_buffer[0], feature_buffer[1],
 341                         feature_buffer[2], feature_buffer[3],
 342                         feature_buffer[4]);
 343
 344                 do {
 345                         retval = usb_control_msg(port->serial->dev,
 346                                         usb_sndctrlpipe(port->serial->dev, 0),
 347                                         HID_REQ_SET_REPORT,
 348                                         USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
 349                                         0x0300, 0, feature_buffer,
 350                                         feature_len, 500);
 351
 352                         if (tries++ >= 3)
 353                                 break;
 354
 355                 } while (retval != feature_len &&
 356                          retval != -ENODEV);
 357
 358                 if (retval != feature_len) {
 359                         dev_err(dev, "%s - failed sending serial line settings - %d\n",
 360                                 __func__, retval);
 361                         cypress_set_dead(port);
 362                 } else {
 363                         spin_lock_irqsave(&priv->lock, flags);
 364                         priv->baud_rate = new_baudrate;
 365                         priv->current_config = feature_buffer[4];
 366                         spin_unlock_irqrestore(&priv->lock, flags);
 367                         /* If we asked for a speed change encode it */
 368                         if (baud_rate)
 369                                 tty_encode_baud_rate(tty,
 370                                         new_baudrate, new_baudrate);
 371                 }
 372         break;
 373         case CYPRESS_GET_CONFIG:
 374                 if (priv->get_cfg_unsafe) {
 375                         /* Not implemented for this device,
 376                            and if we try to do it we're likely
 377                            to crash the hardware. */
 378                         retval = -ENOTTY;
 379                         goto out;
 380                 }
 381                 dev_dbg(dev, "%s - retrieving serial line settings\n", __func__);
 382                 do {
 383                         retval = usb_control_msg(port->serial->dev,
 384                                         usb_rcvctrlpipe(port->serial->dev, 0),
 385                                         HID_REQ_GET_REPORT,
 386                                         USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
 387                                         0x0300, 0, feature_buffer,
 388                                         feature_len, 500);
 389
 390                         if (tries++ >= 3)
 391                                 break;
 392                 } while (retval != feature_len
 393                                                 && retval != -ENODEV);
 394
 395                 if (retval != feature_len) {
 396                         dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
 397                                 __func__, retval);
 398                         cypress_set_dead(port);
 399                         goto out;
 400                 } else {
 401                         spin_lock_irqsave(&priv->lock, flags);
 402                         /* store the config in one byte, and later
 403                            use bit masks to check values */
 404                         priv->current_config = feature_buffer[4];
 405                         priv->baud_rate = get_unaligned_le32(feature_buffer);
 406                         spin_unlock_irqrestore(&priv->lock, flags);
 407                 }
 408         }
 409         spin_lock_irqsave(&priv->lock, flags);
 410         ++priv->cmd_count;
 411         spin_unlock_irqrestore(&priv->lock, flags);
 412 out:
 413         kfree(feature_buffer);
 414         return retval;
 415 } /* cypress_serial_control */
 416
 417
 418 static void cypress_set_dead(struct usb_serial_port *port)
 419 {
 420         struct cypress_private *priv = usb_get_serial_port_data(port);
 421         unsigned long flags;
 422
 423         spin_lock_irqsave(&priv->lock, flags);
 424         if (!priv->comm_is_ok) {
 425                 spin_unlock_irqrestore(&priv->lock, flags);
 426                 return;
 427         }
 428         priv->comm_is_ok = 0;
 429         spin_unlock_irqrestore(&priv->lock, flags);
 430
 431         dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
 432                 "interval might be too short\n", port->port_number);
 433 }
 434
 435
 436 /*****************************************************************************
 437  * Cypress serial driver functions
 438  *****************************************************************************/
 439
 440
 441 static int cypress_generic_port_probe(struct usb_serial_port *port)
 442 {
 443         struct usb_serial *serial = port->serial;
 444         struct cypress_private *priv;
 445
 446         if (!port->interrupt_out_urb || !port->interrupt_in_urb) {
 447                 dev_err(&port->dev, "required endpoint is missing\n");
 448                 return -ENODEV;
 449         }
 450
 451         priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
 452         if (!priv)
 453                 return -ENOMEM;
 454
 455         priv->comm_is_ok = !0;
 456         spin_lock_init(&priv->lock);
 457         if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
 458                 kfree(priv);
 459                 return -ENOMEM;
 460         }
 461
 462         /* Skip reset for FRWD device. It is a workaound:
 463            device hangs if it receives SET_CONFIGURE in Configured
 464            state. */
 465         if (!is_frwd(serial->dev))
 466                 usb_reset_configuration(serial->dev);
 467
 468         priv->cmd_ctrl = 0;
 469         priv->line_control = 0;
 470         priv->rx_flags = 0;
 471         /* Default packet format setting is determined by packet size.
 472            Anything with a size larger then 9 must have a separate
 473            count field since the 3 bit count field is otherwise too
 474            small.  Otherwise we can use the slightly more compact
 475            format.  This is in accordance with the cypress_m8 serial
 476            converter app note. */
 477         if (port->interrupt_out_size > 9)
 478                 priv->pkt_fmt = packet_format_1;
 479         else
 480                 priv->pkt_fmt = packet_format_2;
 481
 482         if (interval > 0) {
 483                 priv->write_urb_interval = interval;
 484                 priv->read_urb_interval = interval;
 485                 dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
 486                         __func__, interval);
 487         } else {
 488                 priv->write_urb_interval = port->interrupt_out_urb->interval;
 489                 priv->read_urb_interval = port->interrupt_in_urb->interval;
 490                 dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
 491                         __func__, priv->read_urb_interval,
 492                         priv->write_urb_interval);
 493         }
 494         usb_set_serial_port_data(port, priv);
 495
 496         port->port.drain_delay = 256;
 497
 498         return 0;
 499 }
 500
 501
 502 static int cypress_earthmate_port_probe(struct usb_serial_port *port)
 503 {
 504         struct usb_serial *serial = port->serial;
 505         struct cypress_private *priv;
 506         int ret;
 507
 508         ret = cypress_generic_port_probe(port);
 509         if (ret) {
 510                 dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
 511                 return ret;
 512         }
 513
 514         priv = usb_get_serial_port_data(port);
 515         priv->chiptype = CT_EARTHMATE;
 516         /* All Earthmate devices use the separated-count packet
 517            format!  Idiotic. */
 518         priv->pkt_fmt = packet_format_1;
 519         if (serial->dev->descriptor.idProduct !=
 520                                 cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
 521                 /* The old original USB Earthmate seemed able to
 522                    handle GET_CONFIG requests; everything they've
 523                    produced since that time crashes if this command is
 524                    attempted :-( */
 525                 dev_dbg(&port->dev,
 526                         "%s - Marking this device as unsafe for GET_CONFIG commands\n",
 527                         __func__);
 528                 priv->get_cfg_unsafe = !0;
 529         }
 530
 531         return 0;
 532 }
 533
 534 static int cypress_hidcom_port_probe(struct usb_serial_port *port)
 535 {
 536         struct cypress_private *priv;
 537         int ret;
 538
 539         ret = cypress_generic_port_probe(port);
 540         if (ret) {
 541                 dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
 542                 return ret;
 543         }
 544
 545         priv = usb_get_serial_port_data(port);
 546         priv->chiptype = CT_CYPHIDCOM;
 547
 548         return 0;
 549 }
 550
 551 static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
 552 {
 553         struct cypress_private *priv;
 554         int ret;
 555
 556         ret = cypress_generic_port_probe(port);
 557         if (ret) {
 558                 dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
 559                 return ret;
 560         }
 561
 562         priv = usb_get_serial_port_data(port);
 563         priv->chiptype = CT_CA42V2;
 564
 565         return 0;
 566 }
 567
 568 static void cypress_port_remove(struct usb_serial_port *port)
 569 {
 570         struct cypress_private *priv;
 571
 572         priv = usb_get_serial_port_data(port);
 573
 574         kfifo_free(&priv->write_fifo);
 575         kfree(priv);
 576 }
 577
 578 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
 579 {
 580         struct cypress_private *priv = usb_get_serial_port_data(port);
 581         struct usb_serial *serial = port->serial;
 582         unsigned long flags;
 583         int result = 0;
 584
 585         if (!priv->comm_is_ok)
 586                 return -EIO;
 587
 588         /* clear halts before open */
 589         usb_clear_halt(serial->dev, 0x81);
 590         usb_clear_halt(serial->dev, 0x02);
 591
 592         spin_lock_irqsave(&priv->lock, flags);
 593         /* reset read/write statistics */
 594         priv->bytes_in = 0;
 595         priv->bytes_out = 0;
 596         priv->cmd_count = 0;
 597         priv->rx_flags = 0;
 598         spin_unlock_irqrestore(&priv->lock, flags);
 599
 600         /* Set termios */
 601         cypress_send(port);
 602
 603         if (tty)
 604                 cypress_set_termios(tty, port, NULL);
 605
 606         /* setup the port and start reading from the device */
 607         usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
 608                 usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
 609                 port->interrupt_in_urb->transfer_buffer,
 610                 port->interrupt_in_urb->transfer_buffer_length,
 611                 cypress_read_int_callback, port, priv->read_urb_interval);
 612         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 613
 614         if (result) {
 615                 dev_err(&port->dev,
 616                         "%s - failed submitting read urb, error %d\n",
 617                                                         __func__, result);
 618                 cypress_set_dead(port);
 619         }
 620
 621         return result;
 622 } /* cypress_open */
 623
 624 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
 625 {
 626         struct cypress_private *priv = usb_get_serial_port_data(port);
 627         /* drop dtr and rts */
 628         spin_lock_irq(&priv->lock);
 629         if (on == 0)
 630                 priv->line_control = 0;
 631         else
 632                 priv->line_control = CONTROL_DTR | CONTROL_RTS;
 633         priv->cmd_ctrl = 1;
 634         spin_unlock_irq(&priv->lock);
 635         cypress_write(NULL, port, NULL, 0);
 636 }
 637
 638 static void cypress_close(struct usb_serial_port *port)
 639 {
 640         struct cypress_private *priv = usb_get_serial_port_data(port);
 641         unsigned long flags;
 642
 643         spin_lock_irqsave(&priv->lock, flags);
 644         kfifo_reset_out(&priv->write_fifo);
 645         spin_unlock_irqrestore(&priv->lock, flags);
 646
 647         dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
 648         usb_kill_urb(port->interrupt_in_urb);
 649         usb_kill_urb(port->interrupt_out_urb);
 650
 651         if (stats)
 652                 dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
 653                         priv->bytes_in, priv->bytes_out, priv->cmd_count);
 654 } /* cypress_close */
 655
 656
 657 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
 658                                         const unsigned char *buf, int count)
 659 {
 660         struct cypress_private *priv = usb_get_serial_port_data(port);
 661
 662         dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
 663
 664         /* line control commands, which need to be executed immediately,
 665            are not put into the buffer for obvious reasons.
 666          */
 667         if (priv->cmd_ctrl) {
 668                 count = 0;
 669                 goto finish;
 670         }
 671
 672         if (!count)
 673                 return count;
 674
 675         count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
 676
 677 finish:
 678         cypress_send(port);
 679
 680         return count;
 681 } /* cypress_write */
 682
 683
 684 static void cypress_send(struct usb_serial_port *port)
 685 {
 686         int count = 0, result, offset, actual_size;
 687         struct cypress_private *priv = usb_get_serial_port_data(port);
 688         struct device *dev = &port->dev;
 689         unsigned long flags;
 690
 691         if (!priv->comm_is_ok)
 692                 return;
 693
 694         dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
 695                 port->interrupt_out_size);
 696
 697         spin_lock_irqsave(&priv->lock, flags);
 698         if (priv->write_urb_in_use) {
 699                 dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
 700                 spin_unlock_irqrestore(&priv->lock, flags);
 701                 return;
 702         }
 703         spin_unlock_irqrestore(&priv->lock, flags);
 704
 705         /* clear buffer */
 706         memset(port->interrupt_out_urb->transfer_buffer, 0,
 707                                                 port->interrupt_out_size);
 708
 709         spin_lock_irqsave(&priv->lock, flags);
 710         switch (priv->pkt_fmt) {
 711         default:
 712         case packet_format_1:
 713                 /* this is for the CY7C64013... */
 714                 offset = 2;
 715                 port->interrupt_out_buffer[0] = priv->line_control;
 716                 break;
 717         case packet_format_2:
 718                 /* this is for the CY7C63743... */
 719                 offset = 1;
 720                 port->interrupt_out_buffer[0] = priv->line_control;
 721                 break;
 722         }
 723
 724         if (priv->line_control & CONTROL_RESET)
 725                 priv->line_control &= ~CONTROL_RESET;
 726
 727         if (priv->cmd_ctrl) {
 728                 priv->cmd_count++;
 729                 dev_dbg(dev, "%s - line control command being issued\n", __func__);
 730                 spin_unlock_irqrestore(&priv->lock, flags);
 731                 goto send;
 732         } else
 733                 spin_unlock_irqrestore(&priv->lock, flags);
 734
 735         count = kfifo_out_locked(&priv->write_fifo,
 736                                         &port->interrupt_out_buffer[offset],
 737                                         port->interrupt_out_size - offset,
 738                                         &priv->lock);
 739         if (count == 0)
 740                 return;
 741
 742         switch (priv->pkt_fmt) {
 743         default:
 744         case packet_format_1:
 745                 port->interrupt_out_buffer[1] = count;
 746                 break;
 747         case packet_format_2:
 748                 port->interrupt_out_buffer[0] |= count;
 749         }
 750
 751         dev_dbg(dev, "%s - count is %d\n", __func__, count);
 752
 753 send:
 754         spin_lock_irqsave(&priv->lock, flags);
 755         priv->write_urb_in_use = 1;
 756         spin_unlock_irqrestore(&priv->lock, flags);
 757
 758         if (priv->cmd_ctrl)
 759                 actual_size = 1;
 760         else
 761                 actual_size = count +
 762                               (priv->pkt_fmt == packet_format_1 ? 2 : 1);
 763
 764         usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
 765                               port->interrupt_out_urb->transfer_buffer);
 766
 767         usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
 768                 usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
 769                 port->interrupt_out_buffer, actual_size,
 770                 cypress_write_int_callback, port, priv->write_urb_interval);
 771         result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
 772         if (result) {
 773                 dev_err_console(port,
 774                                 "%s - failed submitting write urb, error %d\n",
 775                                                         __func__, result);
 776                 priv->write_urb_in_use = 0;
 777                 cypress_set_dead(port);
 778         }
 779
 780         spin_lock_irqsave(&priv->lock, flags);
 781         if (priv->cmd_ctrl)
 782                 priv->cmd_ctrl = 0;
 783
 784         /* do not count the line control and size bytes */
 785         priv->bytes_out += count;
 786         spin_unlock_irqrestore(&priv->lock, flags);
 787
 788         usb_serial_port_softint(port);
 789 } /* cypress_send */
 790
 791
 792 /* returns how much space is available in the soft buffer */
 793 static unsigned int cypress_write_room(struct tty_struct *tty)
 794 {
 795         struct usb_serial_port *port = tty->driver_data;
 796         struct cypress_private *priv = usb_get_serial_port_data(port);
 797         unsigned int room;
 798         unsigned long flags;
 799
 800         spin_lock_irqsave(&priv->lock, flags);
 801         room = kfifo_avail(&priv->write_fifo);
 802         spin_unlock_irqrestore(&priv->lock, flags);
 803
 804         dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
 805         return room;
 806 }
 807
 808
 809 static int cypress_tiocmget(struct tty_struct *tty)
 810 {
 811         struct usb_serial_port *port = tty->driver_data;
 812         struct cypress_private *priv = usb_get_serial_port_data(port);
 813         __u8 status, control;
 814         unsigned int result = 0;
 815         unsigned long flags;
 816
 817         spin_lock_irqsave(&priv->lock, flags);
 818         control = priv->line_control;
 819         status = priv->current_status;
 820         spin_unlock_irqrestore(&priv->lock, flags);
 821
 822         result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
 823                 | ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
 824                 | ((status & UART_CTS)        ? TIOCM_CTS : 0)
 825                 | ((status & UART_DSR)        ? TIOCM_DSR : 0)
 826                 | ((status & UART_RI)         ? TIOCM_RI  : 0)
 827                 | ((status & UART_CD)         ? TIOCM_CD  : 0);
 828
 829         dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
 830
 831         return result;
 832 }
 833
 834
 835 static int cypress_tiocmset(struct tty_struct *tty,
 836                                unsigned int set, unsigned int clear)
 837 {
 838         struct usb_serial_port *port = tty->driver_data;
 839         struct cypress_private *priv = usb_get_serial_port_data(port);
 840         unsigned long flags;
 841
 842         spin_lock_irqsave(&priv->lock, flags);
 843         if (set & TIOCM_RTS)
 844                 priv->line_control |= CONTROL_RTS;
 845         if (set & TIOCM_DTR)
 846                 priv->line_control |= CONTROL_DTR;
 847         if (clear & TIOCM_RTS)
 848                 priv->line_control &= ~CONTROL_RTS;
 849         if (clear & TIOCM_DTR)
 850                 priv->line_control &= ~CONTROL_DTR;
 851         priv->cmd_ctrl = 1;
 852         spin_unlock_irqrestore(&priv->lock, flags);
 853
 854         return cypress_write(tty, port, NULL, 0);
 855 }
 856
 857 static void cypress_earthmate_init_termios(struct tty_struct *tty)
 858 {
 859         tty_encode_baud_rate(tty, 4800, 4800);
 860 }
 861
 862 static void cypress_set_termios(struct tty_struct *tty,
 863                                 struct usb_serial_port *port,
 864                                 const struct ktermios *old_termios)
 865 {
 866         struct cypress_private *priv = usb_get_serial_port_data(port);
 867         struct device *dev = &port->dev;
 868         int data_bits, stop_bits, parity_type, parity_enable;
 869         unsigned int cflag;
 870         unsigned long flags;
 871         __u8 oldlines;
 872         int linechange = 0;
 873
 874         /* Unsupported features need clearing */
 875         tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
 876
 877         cflag = tty->termios.c_cflag;
 878
 879         /* set number of data bits, parity, stop bits */
 880         /* when parity is disabled the parity type bit is ignored */
 881
 882         /* 1 means 2 stop bits, 0 means 1 stop bit */
 883         stop_bits = cflag & CSTOPB ? 1 : 0;
 884
 885         if (cflag & PARENB) {
 886                 parity_enable = 1;
 887                 /* 1 means odd parity, 0 means even parity */
 888                 parity_type = cflag & PARODD ? 1 : 0;
 889         } else
 890                 parity_enable = parity_type = 0;
 891
 892         data_bits = tty_get_char_size(cflag);
 893
 894         spin_lock_irqsave(&priv->lock, flags);
 895         oldlines = priv->line_control;
 896         if ((cflag & CBAUD) == B0) {
 897                 /* drop dtr and rts */
 898                 dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
 899                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 900         } else
 901                 priv->line_control = (CONTROL_DTR | CONTROL_RTS);
 902         spin_unlock_irqrestore(&priv->lock, flags);
 903
 904         dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
 905                 __func__, stop_bits, parity_enable, parity_type, data_bits);
 906
 907         cypress_serial_control(tty, port, tty_get_baud_rate(tty),
 908                         data_bits, stop_bits,
 909                         parity_enable, parity_type,
 910                         0, CYPRESS_SET_CONFIG);
 911
 912         /* we perform a CYPRESS_GET_CONFIG so that the current settings are
 913          * filled into the private structure this should confirm that all is
 914          * working if it returns what we just set */
 915         cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
 916
 917         /* Here we can define custom tty settings for devices; the main tty
 918          * termios flag base comes from empeg.c */
 919
 920         spin_lock_irqsave(&priv->lock, flags);
 921         if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
 922                 dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
 923                 /* define custom termios settings for NMEA protocol */
 924
 925                 tty->termios.c_iflag /* input modes - */
 926                         &= ~(IGNBRK  /* disable ignore break */
 927                         | BRKINT     /* disable break causes interrupt */
 928                         | PARMRK     /* disable mark parity errors */
 929                         | ISTRIP     /* disable clear high bit of input char */
 930                         | INLCR      /* disable translate NL to CR */
 931                         | IGNCR      /* disable ignore CR */
 932                         | ICRNL      /* disable translate CR to NL */
 933                         | IXON);     /* disable enable XON/XOFF flow control */
 934
 935                 tty->termios.c_oflag /* output modes */
 936                         &= ~OPOST;    /* disable postprocess output char */
 937
 938                 tty->termios.c_lflag /* line discipline modes */
 939                         &= ~(ECHO     /* disable echo input characters */
 940                         | ECHONL      /* disable echo new line */
 941                         | ICANON      /* disable erase, kill, werase, and rprnt
 942                                          special characters */
 943                         | ISIG        /* disable interrupt, quit, and suspend
 944                                          special characters */
 945                         | IEXTEN);    /* disable non-POSIX special characters */
 946         } /* CT_CYPHIDCOM: Application should handle this for device */
 947
 948         linechange = (priv->line_control != oldlines);
 949         spin_unlock_irqrestore(&priv->lock, flags);
 950
 951         /* if necessary, set lines */
 952         if (linechange) {
 953                 priv->cmd_ctrl = 1;
 954                 cypress_write(tty, port, NULL, 0);
 955         }
 956 } /* cypress_set_termios */
 957
 958
 959 /* returns amount of data still left in soft buffer */
 960 static unsigned int cypress_chars_in_buffer(struct tty_struct *tty)
 961 {
 962         struct usb_serial_port *port = tty->driver_data;
 963         struct cypress_private *priv = usb_get_serial_port_data(port);
 964         unsigned int chars;
 965         unsigned long flags;
 966
 967         spin_lock_irqsave(&priv->lock, flags);
 968         chars = kfifo_len(&priv->write_fifo);
 969         spin_unlock_irqrestore(&priv->lock, flags);
 970
 971         dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
 972         return chars;
 973 }
 974
 975
 976 static void cypress_throttle(struct tty_struct *tty)
 977 {
 978         struct usb_serial_port *port = tty->driver_data;
 979         struct cypress_private *priv = usb_get_serial_port_data(port);
 980
 981         spin_lock_irq(&priv->lock);
 982         priv->rx_flags = THROTTLED;
 983         spin_unlock_irq(&priv->lock);
 984 }
 985
 986
 987 static void cypress_unthrottle(struct tty_struct *tty)
 988 {
 989         struct usb_serial_port *port = tty->driver_data;
 990         struct cypress_private *priv = usb_get_serial_port_data(port);
 991         int actually_throttled, result;
 992
 993         spin_lock_irq(&priv->lock);
 994         actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
 995         priv->rx_flags = 0;
 996         spin_unlock_irq(&priv->lock);
 997
 998         if (!priv->comm_is_ok)
 999                 return;
1000
1001         if (actually_throttled) {
1002                 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1003                 if (result) {
1004                         dev_err(&port->dev, "%s - failed submitting read urb, "
1005                                         "error %d\n", __func__, result);
1006                         cypress_set_dead(port);
1007                 }
1008         }
1009 }
1010
1011
1012 static void cypress_read_int_callback(struct urb *urb)
1013 {
1014         struct usb_serial_port *port = urb->context;
1015         struct cypress_private *priv = usb_get_serial_port_data(port);
1016         struct device *dev = &urb->dev->dev;
1017         struct tty_struct *tty;
1018         unsigned char *data = urb->transfer_buffer;
1019         unsigned long flags;
1020         char tty_flag = TTY_NORMAL;
1021         int bytes = 0;
1022         int result;
1023         int i = 0;
1024         int status = urb->status;
1025
1026         switch (status) {
1027         case 0: /* success */
1028                 break;
1029         case -ECONNRESET:
1030         case -ENOENT:
1031         case -ESHUTDOWN:
1032                 /* precursor to disconnect so just go away */
1033                 return;
1034         case -EPIPE:
1035                 /* Can't call usb_clear_halt while in_interrupt */
1036                 fallthrough;
1037         default:
1038                 /* something ugly is going on... */
1039                 dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1040                         __func__, status);
1041                 cypress_set_dead(port);
1042                 return;
1043         }
1044
1045         spin_lock_irqsave(&priv->lock, flags);
1046         if (priv->rx_flags & THROTTLED) {
1047                 dev_dbg(dev, "%s - now throttling\n", __func__);
1048                 priv->rx_flags |= ACTUALLY_THROTTLED;
1049                 spin_unlock_irqrestore(&priv->lock, flags);
1050                 return;
1051         }
1052         spin_unlock_irqrestore(&priv->lock, flags);
1053
1054         tty = tty_port_tty_get(&port->port);
1055         if (!tty) {
1056                 dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1057                 return;
1058         }
1059
1060         spin_lock_irqsave(&priv->lock, flags);
1061         result = urb->actual_length;
1062         switch (priv->pkt_fmt) {
1063         default:
1064         case packet_format_1:
1065                 /* This is for the CY7C64013... */
1066                 priv->current_status = data[0] & 0xF8;
1067                 bytes = data[1] + 2;
1068                 i = 2;
1069                 break;
1070         case packet_format_2:
1071                 /* This is for the CY7C63743... */
1072                 priv->current_status = data[0] & 0xF8;
1073                 bytes = (data[0] & 0x07) + 1;
1074                 i = 1;
1075                 break;
1076         }
1077         spin_unlock_irqrestore(&priv->lock, flags);
1078         if (result < bytes) {
1079                 dev_dbg(dev,
1080                         "%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1081                         __func__, result, bytes);
1082                 goto continue_read;
1083         }
1084
1085         usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1086
1087         spin_lock_irqsave(&priv->lock, flags);
1088         /* check to see if status has changed */
1089         if (priv->current_status != priv->prev_status) {
1090                 u8 delta = priv->current_status ^ priv->prev_status;
1091
1092                 if (delta & UART_MSR_MASK) {
1093                         if (delta & UART_CTS)
1094                                 port->icount.cts++;
1095                         if (delta & UART_DSR)
1096                                 port->icount.dsr++;
1097                         if (delta & UART_RI)
1098                                 port->icount.rng++;
1099                         if (delta & UART_CD)
1100                                 port->icount.dcd++;
1101
1102                         wake_up_interruptible(&port->port.delta_msr_wait);
1103                 }
1104
1105                 priv->prev_status = priv->current_status;
1106         }
1107         spin_unlock_irqrestore(&priv->lock, flags);
1108
1109         /* hangup, as defined in acm.c... this might be a bad place for it
1110          * though */
1111         if (tty && !C_CLOCAL(tty) && !(priv->current_status & UART_CD)) {
1112                 dev_dbg(dev, "%s - calling hangup\n", __func__);
1113                 tty_hangup(tty);
1114                 goto continue_read;
1115         }
1116
1117         /* There is one error bit... I'm assuming it is a parity error
1118          * indicator as the generic firmware will set this bit to 1 if a
1119          * parity error occurs.
1120          * I can not find reference to any other error events. */
1121         spin_lock_irqsave(&priv->lock, flags);
1122         if (priv->current_status & CYP_ERROR) {
1123                 spin_unlock_irqrestore(&priv->lock, flags);
1124                 tty_flag = TTY_PARITY;
1125                 dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1126         } else
1127                 spin_unlock_irqrestore(&priv->lock, flags);
1128
1129         /* process read if there is data other than line status */
1130         if (bytes > i) {
1131                 tty_insert_flip_string_fixed_flag(&port->port, data + i,
1132                                 tty_flag, bytes - i);
1133                 tty_flip_buffer_push(&port->port);
1134         }
1135
1136         spin_lock_irqsave(&priv->lock, flags);
1137         /* control and status byte(s) are also counted */
1138         priv->bytes_in += bytes;
1139         spin_unlock_irqrestore(&priv->lock, flags);
1140
1141 continue_read:
1142         tty_kref_put(tty);
1143
1144         /* Continue trying to always read */
1145
1146         if (priv->comm_is_ok) {
1147                 usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1148                                 usb_rcvintpipe(port->serial->dev,
1149                                         port->interrupt_in_endpointAddress),
1150                                 port->interrupt_in_urb->transfer_buffer,
1151                                 port->interrupt_in_urb->transfer_buffer_length,
1152                                 cypress_read_int_callback, port,
1153                                 priv->read_urb_interval);
1154                 result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1155                 if (result && result != -EPERM) {
1156                         dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1157                                 __func__, result);
1158                         cypress_set_dead(port);
1159                 }
1160         }
1161 } /* cypress_read_int_callback */
1162
1163
1164 static void cypress_write_int_callback(struct urb *urb)
1165 {
1166         struct usb_serial_port *port = urb->context;
1167         struct cypress_private *priv = usb_get_serial_port_data(port);
1168         struct device *dev = &urb->dev->dev;
1169         int status = urb->status;
1170
1171         switch (status) {
1172         case 0:
1173                 /* success */
1174                 break;
1175         case -ECONNRESET:
1176         case -ENOENT:
1177         case -ESHUTDOWN:
1178                 /* this urb is terminated, clean up */
1179                 dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1180                         __func__, status);
1181                 priv->write_urb_in_use = 0;
1182                 return;
1183         case -EPIPE:
1184                 /* Cannot call usb_clear_halt while in_interrupt */
1185                 fallthrough;
1186         default:
1187                 dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1188                         __func__, status);
1189                 cypress_set_dead(port);
1190                 break;
1191         }
1192         priv->write_urb_in_use = 0;
1193
1194         /* send any buffered data */
1195         cypress_send(port);
1196 }
1197
1198 module_usb_serial_driver(serial_drivers, id_table_combined);
1199
1200 MODULE_AUTHOR(DRIVER_AUTHOR);
1201 MODULE_DESCRIPTION(DRIVER_DESC);
1202 MODULE_LICENSE("GPL");
1203
1204 module_param(stats, bool, 0644);
1205 MODULE_PARM_DESC(stats, "Enable statistics or not");
1206 module_param(interval, int, 0644);
1207 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1208 module_param(unstable_bauds, bool, 0644);
1209 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");