drivers/usb/serial/pl2303.c

   1 /*
   2  * Prolific PL2303 USB to serial adaptor driver
   3  *
   4  * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
   5  * Copyright (C) 2003 IBM Corp.
   6  *
   7  * Original driver for 2.2.x by anonymous
   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.
  12  *
  13  * See Documentation/usb/usb-serial.txt for more information on using this driver
  14  *
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/init.h>
  20 #include <linux/slab.h>
  21 #include <linux/tty.h>
  22 #include <linux/tty_driver.h>
  23 #include <linux/tty_flip.h>
  24 #include <linux/serial.h>
  25 #include <linux/module.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/spinlock.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/usb.h>
  30 #include <linux/usb/serial.h>
  31 #include "pl2303.h"
  32
  33 /*
  34  * Version Information
  35  */
  36 #define DRIVER_DESC "Prolific PL2303 USB to serial adaptor driver"
  37
  38 static int debug;
  39
  40 #define PL2303_CLOSING_WAIT     (30*HZ)
  41
  42 #define PL2303_BUF_SIZE         1024
  43 #define PL2303_TMP_BUF_SIZE     1024
  44
  45 struct pl2303_buf {
  46         unsigned int    buf_size;
  47         char            *buf_buf;
  48         char            *buf_get;
  49         char            *buf_put;
  50 };
  51
  52 static struct usb_device_id id_table [] = {
  53         { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID) },
  54         { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
  55         { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
  56         { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
  57         { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
  58         { USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
  59         { USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID) },
  60         { USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
  61         { USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
  62         { USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
  63         { USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
  64         { USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
  65         { USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
  66         { USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
  67         { USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
  68         { USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
  69         { USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
  70         { USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
  71         { USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
  72         { USB_DEVICE(SAMSUNG_VENDOR_ID, SAMSUNG_PRODUCT_ID) },
  73         { USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1) },
  74         { USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65) },
  75         { USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75) },
  76         { USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
  77         { USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
  78         { USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
  79         { USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
  80         { USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
  81         { USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
  82         { USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
  83         { USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
  84         { }                                     /* Terminating entry */
  85 };
  86
  87 MODULE_DEVICE_TABLE(usb, id_table);
  88
  89 static struct usb_driver pl2303_driver = {
  90         .name =         "pl2303",
  91         .probe =        usb_serial_probe,
  92         .disconnect =   usb_serial_disconnect,
  93         .id_table =     id_table,
  94         .no_dynamic_id =        1,
  95 };
  96
  97 #define SET_LINE_REQUEST_TYPE           0x21
  98 #define SET_LINE_REQUEST                0x20
  99
 100 #define SET_CONTROL_REQUEST_TYPE        0x21
 101 #define SET_CONTROL_REQUEST             0x22
 102 #define CONTROL_DTR                     0x01
 103 #define CONTROL_RTS                     0x02
 104
 105 #define BREAK_REQUEST_TYPE              0x21
 106 #define BREAK_REQUEST                   0x23
 107 #define BREAK_ON                        0xffff
 108 #define BREAK_OFF                       0x0000
 109
 110 #define GET_LINE_REQUEST_TYPE           0xa1
 111 #define GET_LINE_REQUEST                0x21
 112
 113 #define VENDOR_WRITE_REQUEST_TYPE       0x40
 114 #define VENDOR_WRITE_REQUEST            0x01
 115
 116 #define VENDOR_READ_REQUEST_TYPE        0xc0
 117 #define VENDOR_READ_REQUEST             0x01
 118
 119 #define UART_STATE                      0x08
 120 #define UART_STATE_TRANSIENT_MASK       0x74
 121 #define UART_DCD                        0x01
 122 #define UART_DSR                        0x02
 123 #define UART_BREAK_ERROR                0x04
 124 #define UART_RING                       0x08
 125 #define UART_FRAME_ERROR                0x10
 126 #define UART_PARITY_ERROR               0x20
 127 #define UART_OVERRUN_ERROR              0x40
 128 #define UART_CTS                        0x80
 129
 130 /* function prototypes for a PL2303 serial converter */
 131 static int pl2303_open (struct usb_serial_port *port, struct file *filp);
 132 static void pl2303_close (struct usb_serial_port *port, struct file *filp);
 133 static void pl2303_set_termios (struct usb_serial_port *port,
 134                                 struct termios *old);
 135 static int pl2303_ioctl (struct usb_serial_port *port, struct file *file,
 136                          unsigned int cmd, unsigned long arg);
 137 static void pl2303_read_int_callback (struct urb *urb, struct pt_regs *regs);
 138 static void pl2303_read_bulk_callback (struct urb *urb, struct pt_regs *regs);
 139 static void pl2303_write_bulk_callback (struct urb *urb, struct pt_regs *regs);
 140 static int pl2303_write (struct usb_serial_port *port,
 141                          const unsigned char *buf, int count);
 142 static void pl2303_send (struct usb_serial_port *port);
 143 static int pl2303_write_room(struct usb_serial_port *port);
 144 static int pl2303_chars_in_buffer(struct usb_serial_port *port);
 145 static void pl2303_break_ctl(struct usb_serial_port *port,int break_state);
 146 static int pl2303_tiocmget (struct usb_serial_port *port, struct file *file);
 147 static int pl2303_tiocmset (struct usb_serial_port *port, struct file *file,
 148                             unsigned int set, unsigned int clear);
 149 static int pl2303_startup (struct usb_serial *serial);
 150 static void pl2303_shutdown (struct usb_serial *serial);
 151 static struct pl2303_buf *pl2303_buf_alloc(unsigned int size);
 152 static void pl2303_buf_free(struct pl2303_buf *pb);
 153 static void pl2303_buf_clear(struct pl2303_buf *pb);
 154 static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb);
 155 static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb);
 156 static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
 157         unsigned int count);
 158 static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
 159         unsigned int count);
 160
 161
 162 /* All of the device info needed for the PL2303 SIO serial converter */
 163 static struct usb_serial_driver pl2303_device = {
 164         .driver = {
 165                 .owner =        THIS_MODULE,
 166                 .name =         "pl2303",
 167         },
 168         .id_table =             id_table,
 169         .num_interrupt_in =     NUM_DONT_CARE,
 170         .num_bulk_in =          1,
 171         .num_bulk_out =         1,
 172         .num_ports =            1,
 173         .open =                 pl2303_open,
 174         .close =                pl2303_close,
 175         .write =                pl2303_write,
 176         .ioctl =                pl2303_ioctl,
 177         .break_ctl =            pl2303_break_ctl,
 178         .set_termios =          pl2303_set_termios,
 179         .tiocmget =             pl2303_tiocmget,
 180         .tiocmset =             pl2303_tiocmset,
 181         .read_bulk_callback =   pl2303_read_bulk_callback,
 182         .read_int_callback =    pl2303_read_int_callback,
 183         .write_bulk_callback =  pl2303_write_bulk_callback,
 184         .write_room =           pl2303_write_room,
 185         .chars_in_buffer =      pl2303_chars_in_buffer,
 186         .attach =               pl2303_startup,
 187         .shutdown =             pl2303_shutdown,
 188 };
 189
 190 enum pl2303_type {
 191         type_0,         /* don't know the difference between type 0 and */
 192         type_1,         /* type 1, until someone from prolific tells us... */
 193         HX,             /* HX version of the pl2303 chip */
 194 };
 195
 196 struct pl2303_private {
 197         spinlock_t lock;
 198         struct pl2303_buf *buf;
 199         int write_urb_in_use;
 200         wait_queue_head_t delta_msr_wait;
 201         u8 line_control;
 202         u8 line_status;
 203         u8 termios_initialized;
 204         enum pl2303_type type;
 205 };
 206
 207
 208 static int pl2303_startup(struct usb_serial *serial)
 209 {
 210         struct pl2303_private *priv;
 211         enum pl2303_type type = type_0;
 212         int i;
 213
 214         if (serial->dev->descriptor.bDeviceClass == 0x02)
 215                 type = type_0;
 216         else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
 217                 type = HX;
 218         else if (serial->dev->descriptor.bDeviceClass == 0x00)
 219                 type = type_1;
 220         else if (serial->dev->descriptor.bDeviceClass == 0xFF)
 221                 type = type_1;
 222         dbg("device type: %d", type);
 223
 224         for (i = 0; i < serial->num_ports; ++i) {
 225                 priv = kzalloc(sizeof(struct pl2303_private), GFP_KERNEL);
 226                 if (!priv)
 227                         goto cleanup;
 228                 spin_lock_init(&priv->lock);
 229                 priv->buf = pl2303_buf_alloc(PL2303_BUF_SIZE);
 230                 if (priv->buf == NULL) {
 231                         kfree(priv);
 232                         goto cleanup;
 233                 }
 234                 init_waitqueue_head(&priv->delta_msr_wait);
 235                 priv->type = type;
 236                 usb_set_serial_port_data(serial->port[i], priv);
 237         }
 238         return 0;
 239
 240 cleanup:
 241         for (--i; i>=0; --i) {
 242                 priv = usb_get_serial_port_data(serial->port[i]);
 243                 pl2303_buf_free(priv->buf);
 244                 kfree(priv);
 245                 usb_set_serial_port_data(serial->port[i], NULL);
 246         }
 247         return -ENOMEM;
 248 }
 249
 250 static int set_control_lines(struct usb_device *dev, u8 value)
 251 {
 252         int retval;
 253
 254         retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
 255                                  SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
 256                                  value, 0, NULL, 0, 100);
 257         dbg("%s - value = %d, retval = %d", __FUNCTION__, value, retval);
 258         return retval;
 259 }
 260
 261 static int pl2303_write(struct usb_serial_port *port, const unsigned char *buf,
 262                         int count)
 263 {
 264         struct pl2303_private *priv = usb_get_serial_port_data(port);
 265         unsigned long flags;
 266
 267         dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
 268
 269         if (!count)
 270                 return count;
 271
 272         spin_lock_irqsave(&priv->lock, flags);
 273         count = pl2303_buf_put(priv->buf, buf, count);
 274         spin_unlock_irqrestore(&priv->lock, flags);
 275
 276         pl2303_send(port);
 277
 278         return count;
 279 }
 280
 281 static void pl2303_send(struct usb_serial_port *port)
 282 {
 283         int count, result;
 284         struct pl2303_private *priv = usb_get_serial_port_data(port);
 285         unsigned long flags;
 286
 287         dbg("%s - port %d", __FUNCTION__, port->number);
 288
 289         spin_lock_irqsave(&priv->lock, flags);
 290
 291         if (priv->write_urb_in_use) {
 292                 spin_unlock_irqrestore(&priv->lock, flags);
 293                 return;
 294         }
 295
 296         count = pl2303_buf_get(priv->buf, port->write_urb->transfer_buffer,
 297                                port->bulk_out_size);
 298
 299         if (count == 0) {
 300                 spin_unlock_irqrestore(&priv->lock, flags);
 301                 return;
 302         }
 303
 304         priv->write_urb_in_use = 1;
 305
 306         spin_unlock_irqrestore(&priv->lock, flags);
 307
 308         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count,
 309                               port->write_urb->transfer_buffer);
 310
 311         port->write_urb->transfer_buffer_length = count;
 312         port->write_urb->dev = port->serial->dev;
 313         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 314         if (result) {
 315                 dev_err(&port->dev, "%s - failed submitting write urb,"
 316                         " error %d\n", __FUNCTION__, result);
 317                 priv->write_urb_in_use = 0;
 318                 // TODO: reschedule pl2303_send
 319         }
 320
 321         usb_serial_port_softint(port);
 322 }
 323
 324 static int pl2303_write_room(struct usb_serial_port *port)
 325 {
 326         struct pl2303_private *priv = usb_get_serial_port_data(port);
 327         int room = 0;
 328         unsigned long flags;
 329
 330         dbg("%s - port %d", __FUNCTION__, port->number);
 331
 332         spin_lock_irqsave(&priv->lock, flags);
 333         room = pl2303_buf_space_avail(priv->buf);
 334         spin_unlock_irqrestore(&priv->lock, flags);
 335
 336         dbg("%s - returns %d", __FUNCTION__, room);
 337         return room;
 338 }
 339
 340 static int pl2303_chars_in_buffer(struct usb_serial_port *port)
 341 {
 342         struct pl2303_private *priv = usb_get_serial_port_data(port);
 343         int chars = 0;
 344         unsigned long flags;
 345
 346         dbg("%s - port %d", __FUNCTION__, port->number);
 347
 348         spin_lock_irqsave(&priv->lock, flags);
 349         chars = pl2303_buf_data_avail(priv->buf);
 350         spin_unlock_irqrestore(&priv->lock, flags);
 351
 352         dbg("%s - returns %d", __FUNCTION__, chars);
 353         return chars;
 354 }
 355
 356 static void pl2303_set_termios(struct usb_serial_port *port,
 357                                struct termios *old_termios)
 358 {
 359         struct usb_serial *serial = port->serial;
 360         struct pl2303_private *priv = usb_get_serial_port_data(port);
 361         unsigned long flags;
 362         unsigned int cflag;
 363         unsigned char *buf;
 364         int baud;
 365         int i;
 366         u8 control;
 367
 368         dbg("%s -  port %d", __FUNCTION__, port->number);
 369
 370         if ((!port->tty) || (!port->tty->termios)) {
 371                 dbg("%s - no tty structures", __FUNCTION__);
 372                 return;
 373         }
 374
 375         spin_lock_irqsave(&priv->lock, flags);
 376         if (!priv->termios_initialized) {
 377                 *(port->tty->termios) = tty_std_termios;
 378                 port->tty->termios->c_cflag = B9600 | CS8 | CREAD |
 379                                               HUPCL | CLOCAL;
 380                 priv->termios_initialized = 1;
 381         }
 382         spin_unlock_irqrestore(&priv->lock, flags);
 383
 384         cflag = port->tty->termios->c_cflag;
 385         /* check that they really want us to change something */
 386         if (old_termios) {
 387                 if ((cflag == old_termios->c_cflag) &&
 388                     (RELEVANT_IFLAG(port->tty->termios->c_iflag) ==
 389                      RELEVANT_IFLAG(old_termios->c_iflag))) {
 390                         dbg("%s - nothing to change...", __FUNCTION__);
 391                         return;
 392                 }
 393         }
 394
 395         buf = kzalloc(7, GFP_KERNEL);
 396         if (!buf) {
 397                 dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__);
 398                 return;
 399         }
 400
 401         i = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 402                             GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
 403                             0, 0, buf, 7, 100);
 404         dbg("0xa1:0x21:0:0  %d - %x %x %x %x %x %x %x", i,
 405             buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6]);
 406
 407         if (cflag & CSIZE) {
 408                 switch (cflag & CSIZE) {
 409                         case CS5:       buf[6] = 5;     break;
 410                         case CS6:       buf[6] = 6;     break;
 411                         case CS7:       buf[6] = 7;     break;
 412                         default:
 413                         case CS8:       buf[6] = 8;     break;
 414                 }
 415                 dbg("%s - data bits = %d", __FUNCTION__, buf[6]);
 416         }
 417
 418         baud = 0;
 419         switch (cflag & CBAUD) {
 420                 case B0:        baud = 0;       break;
 421                 case B75:       baud = 75;      break;
 422                 case B150:      baud = 150;     break;
 423                 case B300:      baud = 300;     break;
 424                 case B600:      baud = 600;     break;
 425                 case B1200:     baud = 1200;    break;
 426                 case B1800:     baud = 1800;    break;
 427                 case B2400:     baud = 2400;    break;
 428                 case B4800:     baud = 4800;    break;
 429                 case B9600:     baud = 9600;    break;
 430                 case B19200:    baud = 19200;   break;
 431                 case B38400:    baud = 38400;   break;
 432                 case B57600:    baud = 57600;   break;
 433                 case B115200:   baud = 115200;  break;
 434                 case B230400:   baud = 230400;  break;
 435                 case B460800:   baud = 460800;  break;
 436                 default:
 437                         dev_err(&port->dev, "pl2303 driver does not support"
 438                                 " the baudrate requested (fix it)\n");
 439                         break;
 440         }
 441         dbg("%s - baud = %d", __FUNCTION__, baud);
 442         if (baud) {
 443                 buf[0] = baud & 0xff;
 444                 buf[1] = (baud >> 8) & 0xff;
 445                 buf[2] = (baud >> 16) & 0xff;
 446                 buf[3] = (baud >> 24) & 0xff;
 447         }
 448
 449         /* For reference buf[4]=0 is 1 stop bits */
 450         /* For reference buf[4]=1 is 1.5 stop bits */
 451         /* For reference buf[4]=2 is 2 stop bits */
 452         if (cflag & CSTOPB) {
 453                 buf[4] = 2;
 454                 dbg("%s - stop bits = 2", __FUNCTION__);
 455         } else {
 456                 buf[4] = 0;
 457                 dbg("%s - stop bits = 1", __FUNCTION__);
 458         }
 459
 460         if (cflag & PARENB) {
 461                 /* For reference buf[5]=0 is none parity */
 462                 /* For reference buf[5]=1 is odd parity */
 463                 /* For reference buf[5]=2 is even parity */
 464                 /* For reference buf[5]=3 is mark parity */
 465                 /* For reference buf[5]=4 is space parity */
 466                 if (cflag & PARODD) {
 467                         buf[5] = 1;
 468                         dbg("%s - parity = odd", __FUNCTION__);
 469                 } else {
 470                         buf[5] = 2;
 471                         dbg("%s - parity = even", __FUNCTION__);
 472                 }
 473         } else {
 474                 buf[5] = 0;
 475                 dbg("%s - parity = none", __FUNCTION__);
 476         }
 477
 478         i = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 479                             SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
 480                             0, 0, buf, 7, 100);
 481         dbg("0x21:0x20:0:0  %d", i);
 482
 483         /* change control lines if we are switching to or from B0 */
 484         spin_lock_irqsave(&priv->lock, flags);
 485         control = priv->line_control;
 486         if ((cflag & CBAUD) == B0)
 487                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 488         else
 489                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 490         if (control != priv->line_control) {
 491                 control = priv->line_control;
 492                 spin_unlock_irqrestore(&priv->lock, flags);
 493                 set_control_lines(serial->dev, control);
 494         } else {
 495                 spin_unlock_irqrestore(&priv->lock, flags);
 496         }
 497
 498         buf[0] = buf[1] = buf[2] = buf[3] = buf[4] = buf[5] = buf[6] = 0;
 499
 500         i = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 501                             GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
 502                             0, 0, buf, 7, 100);
 503         dbg("0xa1:0x21:0:0  %d - %x %x %x %x %x %x %x", i,
 504              buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6]);
 505
 506         if (cflag & CRTSCTS) {
 507                 __u16 index;
 508                 if (priv->type == HX)
 509                         index = 0x61;
 510                 else
 511                         index = 0x41;
 512                 i = usb_control_msg(serial->dev,
 513                                     usb_sndctrlpipe(serial->dev, 0),
 514                                     VENDOR_WRITE_REQUEST,
 515                                     VENDOR_WRITE_REQUEST_TYPE,
 516                                     0x0, index, NULL, 0, 100);
 517                 dbg("0x40:0x1:0x0:0x%x  %d", index, i);
 518         }
 519
 520         kfree(buf);
 521 }
 522
 523 static int pl2303_open(struct usb_serial_port *port, struct file *filp)
 524 {
 525         struct termios tmp_termios;
 526         struct usb_serial *serial = port->serial;
 527         struct pl2303_private *priv = usb_get_serial_port_data(port);
 528         unsigned char *buf;
 529         int result;
 530
 531         dbg("%s -  port %d", __FUNCTION__, port->number);
 532
 533         if (priv->type != HX) {
 534                 usb_clear_halt(serial->dev, port->write_urb->pipe);
 535                 usb_clear_halt(serial->dev, port->read_urb->pipe);
 536         }
 537
 538         buf = kmalloc(10, GFP_KERNEL);
 539         if (buf==NULL)
 540                 return -ENOMEM;
 541
 542 #define FISH(a,b,c,d)                                                           \
 543         result=usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev,0),     \
 544                                b, a, c, d, buf, 1, 100);                        \
 545         dbg("0x%x:0x%x:0x%x:0x%x  %d - %x",a,b,c,d,result,buf[0]);
 546
 547 #define SOUP(a,b,c,d)                                                           \
 548         result=usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev,0),     \
 549                                b, a, c, d, NULL, 0, 100);                       \
 550         dbg("0x%x:0x%x:0x%x:0x%x  %d",a,b,c,d,result);
 551
 552         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 553         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 0x0404, 0);
 554         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 555         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8383, 0);
 556         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 557         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 0x0404, 1);
 558         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 559         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8383, 0);
 560         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 0, 1);
 561         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 1, 0);
 562
 563         if (priv->type == HX) {
 564                 /* HX chip */
 565                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 2, 0x44);
 566                 /* reset upstream data pipes */
 567                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 8, 0);
 568                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 9, 0);
 569         } else {
 570                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 2, 0x24);
 571         }
 572
 573         kfree(buf);
 574
 575         /* Setup termios */
 576         if (port->tty) {
 577                 pl2303_set_termios(port, &tmp_termios);
 578         }
 579
 580         //FIXME: need to assert RTS and DTR if CRTSCTS off
 581
 582         dbg("%s - submitting read urb", __FUNCTION__);
 583         port->read_urb->dev = serial->dev;
 584         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 585         if (result) {
 586                 dev_err(&port->dev, "%s - failed submitting read urb,"
 587                         " error %d\n", __FUNCTION__, result);
 588                 pl2303_close(port, NULL);
 589                 return -EPROTO;
 590         }
 591
 592         dbg("%s - submitting interrupt urb", __FUNCTION__);
 593         port->interrupt_in_urb->dev = serial->dev;
 594         result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 595         if (result) {
 596                 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
 597                         " error %d\n", __FUNCTION__, result);
 598                 pl2303_close(port, NULL);
 599                 return -EPROTO;
 600         }
 601         return 0;
 602 }
 603
 604 static void pl2303_close(struct usb_serial_port *port, struct file *filp)
 605 {
 606         struct pl2303_private *priv = usb_get_serial_port_data(port);
 607         unsigned long flags;
 608         unsigned int c_cflag;
 609         int bps;
 610         long timeout;
 611         wait_queue_t wait;
 612
 613         dbg("%s - port %d", __FUNCTION__, port->number);
 614
 615         /* wait for data to drain from the buffer */
 616         spin_lock_irqsave(&priv->lock, flags);
 617         timeout = PL2303_CLOSING_WAIT;
 618         init_waitqueue_entry(&wait, current);
 619         add_wait_queue(&port->tty->write_wait, &wait);
 620         for (;;) {
 621                 set_current_state(TASK_INTERRUPTIBLE);
 622                 if (pl2303_buf_data_avail(priv->buf) == 0 ||
 623                     timeout == 0 || signal_pending(current) ||
 624                     !usb_get_intfdata(port->serial->interface)) /* disconnect */
 625                         break;
 626                 spin_unlock_irqrestore(&priv->lock, flags);
 627                 timeout = schedule_timeout(timeout);
 628                 spin_lock_irqsave(&priv->lock, flags);
 629         }
 630         set_current_state(TASK_RUNNING);
 631         remove_wait_queue(&port->tty->write_wait, &wait);
 632         /* clear out any remaining data in the buffer */
 633         pl2303_buf_clear(priv->buf);
 634         spin_unlock_irqrestore(&priv->lock, flags);
 635
 636         /* wait for characters to drain from the device */
 637         /* (this is long enough for the entire 256 byte */
 638         /* pl2303 hardware buffer to drain with no flow */
 639         /* control for data rates of 1200 bps or more, */
 640         /* for lower rates we should really know how much */
 641         /* data is in the buffer to compute a delay */
 642         /* that is not unnecessarily long) */
 643         bps = tty_get_baud_rate(port->tty);
 644         if (bps > 1200)
 645                 timeout = max((HZ*2560)/bps,HZ/10);
 646         else
 647                 timeout = 2*HZ;
 648         schedule_timeout_interruptible(timeout);
 649
 650         /* shutdown our urbs */
 651         dbg("%s - shutting down urbs", __FUNCTION__);
 652         usb_kill_urb(port->write_urb);
 653         usb_kill_urb(port->read_urb);
 654         usb_kill_urb(port->interrupt_in_urb);
 655
 656         if (port->tty) {
 657                 c_cflag = port->tty->termios->c_cflag;
 658                 if (c_cflag & HUPCL) {
 659                         /* drop DTR and RTS */
 660                         spin_lock_irqsave(&priv->lock, flags);
 661                         priv->line_control = 0;
 662                         spin_unlock_irqrestore(&priv->lock, flags);
 663                         set_control_lines(port->serial->dev, 0);
 664                 }
 665         }
 666 }
 667
 668 static int pl2303_tiocmset(struct usb_serial_port *port, struct file *file,
 669                            unsigned int set, unsigned int clear)
 670 {
 671         struct pl2303_private *priv = usb_get_serial_port_data(port);
 672         unsigned long flags;
 673         u8 control;
 674
 675         if (!usb_get_intfdata(port->serial->interface))
 676                 return -ENODEV;
 677
 678         spin_lock_irqsave(&priv->lock, flags);
 679         if (set & TIOCM_RTS)
 680                 priv->line_control |= CONTROL_RTS;
 681         if (set & TIOCM_DTR)
 682                 priv->line_control |= CONTROL_DTR;
 683         if (clear & TIOCM_RTS)
 684                 priv->line_control &= ~CONTROL_RTS;
 685         if (clear & TIOCM_DTR)
 686                 priv->line_control &= ~CONTROL_DTR;
 687         control = priv->line_control;
 688         spin_unlock_irqrestore(&priv->lock, flags);
 689
 690         return set_control_lines(port->serial->dev, control);
 691 }
 692
 693 static int pl2303_tiocmget(struct usb_serial_port *port, struct file *file)
 694 {
 695         struct pl2303_private *priv = usb_get_serial_port_data(port);
 696         unsigned long flags;
 697         unsigned int mcr;
 698         unsigned int status;
 699         unsigned int result;
 700
 701         dbg("%s (%d)", __FUNCTION__, port->number);
 702
 703         if (!usb_get_intfdata(port->serial->interface))
 704                 return -ENODEV;
 705
 706         spin_lock_irqsave(&priv->lock, flags);
 707         mcr = priv->line_control;
 708         status = priv->line_status;
 709         spin_unlock_irqrestore(&priv->lock, flags);
 710
 711         result = ((mcr & CONTROL_DTR)           ? TIOCM_DTR : 0)
 712                   | ((mcr & CONTROL_RTS)        ? TIOCM_RTS : 0)
 713                   | ((status & UART_CTS)        ? TIOCM_CTS : 0)
 714                   | ((status & UART_DSR)        ? TIOCM_DSR : 0)
 715                   | ((status & UART_RING)       ? TIOCM_RI  : 0)
 716                   | ((status & UART_DCD)        ? TIOCM_CD  : 0);
 717
 718         dbg("%s - result = %x", __FUNCTION__, result);
 719
 720         return result;
 721 }
 722
 723 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 724 {
 725         struct pl2303_private *priv = usb_get_serial_port_data(port);
 726         unsigned long flags;
 727         unsigned int prevstatus;
 728         unsigned int status;
 729         unsigned int changed;
 730
 731         spin_lock_irqsave(&priv->lock, flags);
 732         prevstatus = priv->line_status;
 733         spin_unlock_irqrestore(&priv->lock, flags);
 734
 735         while (1) {
 736                 interruptible_sleep_on(&priv->delta_msr_wait);
 737                 /* see if a signal did it */
 738                 if (signal_pending(current))
 739                         return -ERESTARTSYS;
 740
 741                 spin_lock_irqsave(&priv->lock, flags);
 742                 status = priv->line_status;
 743                 spin_unlock_irqrestore(&priv->lock, flags);
 744
 745                 changed=prevstatus^status;
 746
 747                 if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
 748                     ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
 749                     ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
 750                     ((arg & TIOCM_CTS) && (changed & UART_CTS)) ) {
 751                         return 0;
 752                 }
 753                 prevstatus = status;
 754         }
 755         /* NOTREACHED */
 756         return 0;
 757 }
 758
 759 static int pl2303_ioctl(struct usb_serial_port *port, struct file *file,
 760                         unsigned int cmd, unsigned long arg)
 761 {
 762         dbg("%s (%d) cmd = 0x%04x", __FUNCTION__, port->number, cmd);
 763
 764         switch (cmd) {
 765                 case TIOCMIWAIT:
 766                         dbg("%s (%d) TIOCMIWAIT", __FUNCTION__,  port->number);
 767                         return wait_modem_info(port, arg);
 768
 769                 default:
 770                         dbg("%s not supported = 0x%04x", __FUNCTION__, cmd);
 771                         break;
 772         }
 773
 774         return -ENOIOCTLCMD;
 775 }
 776
 777 static void pl2303_break_ctl(struct usb_serial_port *port, int break_state)
 778 {
 779         struct usb_serial *serial = port->serial;
 780         u16 state;
 781         int result;
 782
 783         dbg("%s - port %d", __FUNCTION__, port->number);
 784
 785         if (break_state == 0)
 786                 state = BREAK_OFF;
 787         else
 788                 state = BREAK_ON;
 789         dbg("%s - turning break %s", __FUNCTION__, state==BREAK_OFF ? "off" : "on");
 790
 791         result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 792                                  BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
 793                                  0, NULL, 0, 100);
 794         if (result)
 795                 dbg("%s - error sending break = %d", __FUNCTION__, result);
 796 }
 797
 798 static void pl2303_shutdown(struct usb_serial *serial)
 799 {
 800         int i;
 801         struct pl2303_private *priv;
 802
 803         dbg("%s", __FUNCTION__);
 804
 805         for (i = 0; i < serial->num_ports; ++i) {
 806                 priv = usb_get_serial_port_data(serial->port[i]);
 807                 if (priv) {
 808                         pl2303_buf_free(priv->buf);
 809                         kfree(priv);
 810                         usb_set_serial_port_data(serial->port[i], NULL);
 811                 }
 812         }
 813 }
 814
 815 static void pl2303_update_line_status(struct usb_serial_port *port,
 816                                       unsigned char *data,
 817                                       unsigned int actual_length)
 818 {
 819
 820         struct pl2303_private *priv = usb_get_serial_port_data(port);
 821         unsigned long flags;
 822         u8 status_idx = UART_STATE;
 823         u8 length = UART_STATE + 1;
 824
 825         if ((le16_to_cpu(port->serial->dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&
 826             (le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X65 ||
 827              le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_SX1 ||
 828              le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X75)) {
 829                 length = 1;
 830                 status_idx = 0;
 831         }
 832
 833         if (actual_length < length)
 834                 return;
 835
 836         /* Save off the uart status for others to look at */
 837         spin_lock_irqsave(&priv->lock, flags);
 838         priv->line_status = data[status_idx];
 839         spin_unlock_irqrestore(&priv->lock, flags);
 840         wake_up_interruptible(&priv->delta_msr_wait);
 841 }
 842
 843 static void pl2303_read_int_callback(struct urb *urb, struct pt_regs *regs)
 844 {
 845         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
 846         unsigned char *data = urb->transfer_buffer;
 847         unsigned int actual_length = urb->actual_length;
 848         int status;
 849
 850         dbg("%s (%d)", __FUNCTION__, port->number);
 851
 852         switch (urb->status) {
 853         case 0:
 854                 /* success */
 855                 break;
 856         case -ECONNRESET:
 857         case -ENOENT:
 858         case -ESHUTDOWN:
 859                 /* this urb is terminated, clean up */
 860                 dbg("%s - urb shutting down with status: %d", __FUNCTION__,
 861                     urb->status);
 862                 return;
 863         default:
 864                 dbg("%s - nonzero urb status received: %d", __FUNCTION__,
 865                     urb->status);
 866                 goto exit;
 867         }
 868
 869         usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
 870                               urb->actual_length, urb->transfer_buffer);
 871
 872         pl2303_update_line_status(port, data, actual_length);
 873
 874 exit:
 875         status = usb_submit_urb(urb, GFP_ATOMIC);
 876         if (status)
 877                 dev_err(&urb->dev->dev,
 878                         "%s - usb_submit_urb failed with result %d\n",
 879                         __FUNCTION__, status);
 880 }
 881
 882 static void pl2303_read_bulk_callback(struct urb *urb, struct pt_regs *regs)
 883 {
 884         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
 885         struct pl2303_private *priv = usb_get_serial_port_data(port);
 886         struct tty_struct *tty;
 887         unsigned char *data = urb->transfer_buffer;
 888         unsigned long flags;
 889         int i;
 890         int result;
 891         u8 status;
 892         char tty_flag;
 893
 894         dbg("%s - port %d", __FUNCTION__, port->number);
 895
 896         if (urb->status) {
 897                 dbg("%s - urb->status = %d", __FUNCTION__, urb->status);
 898                 if (!port->open_count) {
 899                         dbg("%s - port is closed, exiting.", __FUNCTION__);
 900                         return;
 901                 }
 902                 if (urb->status == -EPROTO) {
 903                         /* PL2303 mysteriously fails with -EPROTO reschedule
 904                          * the read */
 905                         dbg("%s - caught -EPROTO, resubmitting the urb",
 906                             __FUNCTION__);
 907                         urb->status = 0;
 908                         urb->dev = port->serial->dev;
 909                         result = usb_submit_urb(urb, GFP_ATOMIC);
 910                         if (result)
 911                                 dev_err(&urb->dev->dev, "%s - failed"
 912                                         " resubmitting read urb, error %d\n",
 913                                         __FUNCTION__, result);
 914                         return;
 915                 }
 916                 dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
 917                 return;
 918         }
 919
 920         usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
 921                               urb->actual_length, data);
 922
 923         /* get tty_flag from status */
 924         tty_flag = TTY_NORMAL;
 925
 926         spin_lock_irqsave(&priv->lock, flags);
 927         status = priv->line_status;
 928         priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
 929         spin_unlock_irqrestore(&priv->lock, flags);
 930         wake_up_interruptible(&priv->delta_msr_wait);
 931
 932         /* break takes precedence over parity, */
 933         /* which takes precedence over framing errors */
 934         if (status & UART_BREAK_ERROR )
 935                 tty_flag = TTY_BREAK;
 936         else if (status & UART_PARITY_ERROR)
 937                 tty_flag = TTY_PARITY;
 938         else if (status & UART_FRAME_ERROR)
 939                 tty_flag = TTY_FRAME;
 940         dbg("%s - tty_flag = %d", __FUNCTION__, tty_flag);
 941
 942         tty = port->tty;
 943         if (tty && urb->actual_length) {
 944                 tty_buffer_request_room(tty, urb->actual_length + 1);
 945                 /* overrun is special, not associated with a char */
 946                 if (status & UART_OVERRUN_ERROR)
 947                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 948                 for (i = 0; i < urb->actual_length; ++i)
 949                         tty_insert_flip_char(tty, data[i], tty_flag);
 950                 tty_flip_buffer_push(tty);
 951         }
 952
 953         /* Schedule the next read _if_ we are still open */
 954         if (port->open_count) {
 955                 urb->dev = port->serial->dev;
 956                 result = usb_submit_urb(urb, GFP_ATOMIC);
 957                 if (result)
 958                         dev_err(&urb->dev->dev, "%s - failed resubmitting"
 959                                 " read urb, error %d\n", __FUNCTION__, result);
 960         }
 961
 962         return;
 963 }
 964
 965 static void pl2303_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
 966 {
 967         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
 968         struct pl2303_private *priv = usb_get_serial_port_data(port);
 969         int result;
 970
 971         dbg("%s - port %d", __FUNCTION__, port->number);
 972
 973         switch (urb->status) {
 974         case 0:
 975                 /* success */
 976                 break;
 977         case -ECONNRESET:
 978         case -ENOENT:
 979         case -ESHUTDOWN:
 980                 /* this urb is terminated, clean up */
 981                 dbg("%s - urb shutting down with status: %d", __FUNCTION__,
 982                     urb->status);
 983                 priv->write_urb_in_use = 0;
 984                 return;
 985         default:
 986                 /* error in the urb, so we have to resubmit it */
 987                 dbg("%s - Overflow in write", __FUNCTION__);
 988                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__,
 989                     urb->status);
 990                 port->write_urb->transfer_buffer_length = 1;
 991                 port->write_urb->dev = port->serial->dev;
 992                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 993                 if (result)
 994                         dev_err(&urb->dev->dev, "%s - failed resubmitting write"
 995                                 " urb, error %d\n", __FUNCTION__, result);
 996                 else
 997                         return;
 998         }
 999
1000         priv->write_urb_in_use = 0;
1001
1002         /* send any buffered data */
1003         pl2303_send(port);
1004 }
1005
1006 /*
1007  * pl2303_buf_alloc
1008  *
1009  * Allocate a circular buffer and all associated memory.
1010  */
1011 static struct pl2303_buf *pl2303_buf_alloc(unsigned int size)
1012 {
1013         struct pl2303_buf *pb;
1014
1015         if (size == 0)
1016                 return NULL;
1017
1018         pb = (struct pl2303_buf *)kmalloc(sizeof(struct pl2303_buf), GFP_KERNEL);
1019         if (pb == NULL)
1020                 return NULL;
1021
1022         pb->buf_buf = kmalloc(size, GFP_KERNEL);
1023         if (pb->buf_buf == NULL) {
1024                 kfree(pb);
1025                 return NULL;
1026         }
1027
1028         pb->buf_size = size;
1029         pb->buf_get = pb->buf_put = pb->buf_buf;
1030
1031         return pb;
1032 }
1033
1034 /*
1035  * pl2303_buf_free
1036  *
1037  * Free the buffer and all associated memory.
1038  */
1039 static void pl2303_buf_free(struct pl2303_buf *pb)
1040 {
1041         if (pb) {
1042                 kfree(pb->buf_buf);
1043                 kfree(pb);
1044         }
1045 }
1046
1047 /*
1048  * pl2303_buf_clear
1049  *
1050  * Clear out all data in the circular buffer.
1051  */
1052 static void pl2303_buf_clear(struct pl2303_buf *pb)
1053 {
1054         if (pb != NULL)
1055                 pb->buf_get = pb->buf_put;
1056                 /* equivalent to a get of all data available */
1057 }
1058
1059 /*
1060  * pl2303_buf_data_avail
1061  *
1062  * Return the number of bytes of data available in the circular
1063  * buffer.
1064  */
1065 static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb)
1066 {
1067         if (pb == NULL)
1068                 return 0;
1069
1070         return ((pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size);
1071 }
1072
1073 /*
1074  * pl2303_buf_space_avail
1075  *
1076  * Return the number of bytes of space available in the circular
1077  * buffer.
1078  */
1079 static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb)
1080 {
1081         if (pb == NULL)
1082                 return 0;
1083
1084         return ((pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size);
1085 }
1086
1087 /*
1088  * pl2303_buf_put
1089  *
1090  * Copy data data from a user buffer and put it into the circular buffer.
1091  * Restrict to the amount of space available.
1092  *
1093  * Return the number of bytes copied.
1094  */
1095 static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
1096                                    unsigned int count)
1097 {
1098         unsigned int len;
1099
1100         if (pb == NULL)
1101                 return 0;
1102
1103         len  = pl2303_buf_space_avail(pb);
1104         if (count > len)
1105                 count = len;
1106
1107         if (count == 0)
1108                 return 0;
1109
1110         len = pb->buf_buf + pb->buf_size - pb->buf_put;
1111         if (count > len) {
1112                 memcpy(pb->buf_put, buf, len);
1113                 memcpy(pb->buf_buf, buf+len, count - len);
1114                 pb->buf_put = pb->buf_buf + count - len;
1115         } else {
1116                 memcpy(pb->buf_put, buf, count);
1117                 if (count < len)
1118                         pb->buf_put += count;
1119                 else /* count == len */
1120                         pb->buf_put = pb->buf_buf;
1121         }
1122
1123         return count;
1124 }
1125
1126 /*
1127  * pl2303_buf_get
1128  *
1129  * Get data from the circular buffer and copy to the given buffer.
1130  * Restrict to the amount of data available.
1131  *
1132  * Return the number of bytes copied.
1133  */
1134 static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
1135                                    unsigned int count)
1136 {
1137         unsigned int len;
1138
1139         if (pb == NULL)
1140                 return 0;
1141
1142         len = pl2303_buf_data_avail(pb);
1143         if (count > len)
1144                 count = len;
1145
1146         if (count == 0)
1147                 return 0;
1148
1149         len = pb->buf_buf + pb->buf_size - pb->buf_get;
1150         if (count > len) {
1151                 memcpy(buf, pb->buf_get, len);
1152                 memcpy(buf+len, pb->buf_buf, count - len);
1153                 pb->buf_get = pb->buf_buf + count - len;
1154         } else {
1155                 memcpy(buf, pb->buf_get, count);
1156                 if (count < len)
1157                         pb->buf_get += count;
1158                 else /* count == len */
1159                         pb->buf_get = pb->buf_buf;
1160         }
1161
1162         return count;
1163 }
1164
1165 static int __init pl2303_init(void)
1166 {
1167         int retval;
1168
1169         retval = usb_serial_register(&pl2303_device);
1170         if (retval)
1171                 goto failed_usb_serial_register;
1172         retval = usb_register(&pl2303_driver);
1173         if (retval)
1174                 goto failed_usb_register;
1175         info(DRIVER_DESC);
1176         return 0;
1177 failed_usb_register:
1178         usb_serial_deregister(&pl2303_device);
1179 failed_usb_serial_register:
1180         return retval;
1181 }
1182
1183 static void __exit pl2303_exit(void)
1184 {
1185         usb_deregister(&pl2303_driver);
1186         usb_serial_deregister(&pl2303_device);
1187 }
1188
1189 module_init(pl2303_init);
1190 module_exit(pl2303_exit);
1191
1192 MODULE_DESCRIPTION(DRIVER_DESC);
1193 MODULE_LICENSE("GPL");
1194
1195 module_param(debug, bool, S_IRUGO | S_IWUSR);
1196 MODULE_PARM_DESC(debug, "Debug enabled or not");
1197