git.oblomov.eu Git - linux-2.6/blob - 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(OTI_VENDOR_ID, OTI_PRODUCT_ID) },
  83         { USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
  84         { USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
  85         { }                                     /* Terminating entry */
  86 };
  87
  88 MODULE_DEVICE_TABLE (usb, id_table);
  89
  90 static struct usb_driver pl2303_driver = {
  91         .name =         "pl2303",
  92         .probe =        usb_serial_probe,
  93         .disconnect =   usb_serial_disconnect,
  94         .id_table =     id_table,
  95         .no_dynamic_id =        1,
  96 };
  97
  98 #define SET_LINE_REQUEST_TYPE           0x21
  99 #define SET_LINE_REQUEST                0x20
 100
 101 #define SET_CONTROL_REQUEST_TYPE        0x21
 102 #define SET_CONTROL_REQUEST             0x22
 103 #define CONTROL_DTR                     0x01
 104 #define CONTROL_RTS                     0x02
 105
 106 #define BREAK_REQUEST_TYPE              0x21
 107 #define BREAK_REQUEST                   0x23
 108 #define BREAK_ON                        0xffff
 109 #define BREAK_OFF                       0x0000
 110
 111 #define GET_LINE_REQUEST_TYPE           0xa1
 112 #define GET_LINE_REQUEST                0x21
 113
 114 #define VENDOR_WRITE_REQUEST_TYPE       0x40
 115 #define VENDOR_WRITE_REQUEST            0x01
 116
 117 #define VENDOR_READ_REQUEST_TYPE        0xc0
 118 #define VENDOR_READ_REQUEST             0x01
 119
 120 #define UART_STATE                      0x08
 121 #define UART_STATE_TRANSIENT_MASK       0x74
 122 #define UART_DCD                        0x01
 123 #define UART_DSR                        0x02
 124 #define UART_BREAK_ERROR                0x04
 125 #define UART_RING                       0x08
 126 #define UART_FRAME_ERROR                0x10
 127 #define UART_PARITY_ERROR               0x20
 128 #define UART_OVERRUN_ERROR              0x40
 129 #define UART_CTS                        0x80
 130
 131 /* function prototypes for a PL2303 serial converter */
 132 static int pl2303_open (struct usb_serial_port *port, struct file *filp);
 133 static void pl2303_close (struct usb_serial_port *port, struct file *filp);
 134 static void pl2303_set_termios (struct usb_serial_port *port,
 135                                 struct termios *old);
 136 static int pl2303_ioctl (struct usb_serial_port *port, struct file *file,
 137                          unsigned int cmd, unsigned long arg);
 138 static void pl2303_read_int_callback (struct urb *urb, struct pt_regs *regs);
 139 static void pl2303_read_bulk_callback (struct urb *urb, struct pt_regs *regs);
 140 static void pl2303_write_bulk_callback (struct urb *urb, struct pt_regs *regs);
 141 static int pl2303_write (struct usb_serial_port *port,
 142                          const unsigned char *buf, int count);
 143 static void pl2303_send (struct usb_serial_port *port);
 144 static int pl2303_write_room(struct usb_serial_port *port);
 145 static int pl2303_chars_in_buffer(struct usb_serial_port *port);
 146 static void pl2303_break_ctl(struct usb_serial_port *port,int break_state);
 147 static int pl2303_tiocmget (struct usb_serial_port *port, struct file *file);
 148 static int pl2303_tiocmset (struct usb_serial_port *port, struct file *file,
 149                             unsigned int set, unsigned int clear);
 150 static int pl2303_startup (struct usb_serial *serial);
 151 static void pl2303_shutdown (struct usb_serial *serial);
 152 static struct pl2303_buf *pl2303_buf_alloc(unsigned int size);
 153 static void pl2303_buf_free(struct pl2303_buf *pb);
 154 static void pl2303_buf_clear(struct pl2303_buf *pb);
 155 static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb);
 156 static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb);
 157 static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
 158         unsigned int count);
 159 static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
 160         unsigned int count);
 161
 162
 163 /* All of the device info needed for the PL2303 SIO serial converter */
 164 static struct usb_serial_driver pl2303_device = {
 165         .driver = {
 166                 .owner =        THIS_MODULE,
 167                 .name =         "pl2303",
 168         },
 169         .id_table =             id_table,
 170         .num_interrupt_in =     NUM_DONT_CARE,
 171         .num_bulk_in =          1,
 172         .num_bulk_out =         1,
 173         .num_ports =            1,
 174         .open =                 pl2303_open,
 175         .close =                pl2303_close,
 176         .write =                pl2303_write,
 177         .ioctl =                pl2303_ioctl,
 178         .break_ctl =            pl2303_break_ctl,
 179         .set_termios =          pl2303_set_termios,
 180         .tiocmget =             pl2303_tiocmget,
 181         .tiocmset =             pl2303_tiocmset,
 182         .read_bulk_callback =   pl2303_read_bulk_callback,
 183         .read_int_callback =    pl2303_read_int_callback,
 184         .write_bulk_callback =  pl2303_write_bulk_callback,
 185         .write_room =           pl2303_write_room,
 186         .chars_in_buffer =      pl2303_chars_in_buffer,
 187         .attach =               pl2303_startup,
 188         .shutdown =             pl2303_shutdown,
 189 };
 190
 191 enum pl2303_type {
 192         type_0,         /* don't know the difference between type 0 and */
 193         type_1,         /* type 1, until someone from prolific tells us... */
 194         HX,             /* HX version of the pl2303 chip */
 195 };
 196
 197 struct pl2303_private {
 198         spinlock_t lock;
 199         struct pl2303_buf *buf;
 200         int write_urb_in_use;
 201         wait_queue_head_t delta_msr_wait;
 202         u8 line_control;
 203         u8 line_status;
 204         u8 termios_initialized;
 205         enum pl2303_type type;
 206 };
 207
 208
 209 static int pl2303_startup (struct usb_serial *serial)
 210 {
 211         struct pl2303_private *priv;
 212         enum pl2303_type type = type_0;
 213         int i;
 214
 215         if (serial->dev->descriptor.bDeviceClass == 0x02)
 216                 type = type_0;
 217         else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
 218                 type = HX;
 219         else if (serial->dev->descriptor.bDeviceClass == 0x00)
 220                 type = type_1;
 221         else if (serial->dev->descriptor.bDeviceClass == 0xFF)
 222                 type = type_1;
 223         dbg("device type: %d", type);
 224
 225         for (i = 0; i < serial->num_ports; ++i) {
 226                 priv = kzalloc(sizeof(struct pl2303_private), GFP_KERNEL);
 227                 if (!priv)
 228                         goto cleanup;
 229                 spin_lock_init(&priv->lock);
 230                 priv->buf = pl2303_buf_alloc(PL2303_BUF_SIZE);
 231                 if (priv->buf == NULL) {
 232                         kfree(priv);
 233                         goto cleanup;
 234                 }
 235                 init_waitqueue_head(&priv->delta_msr_wait);
 236                 priv->type = type;
 237                 usb_set_serial_port_data(serial->port[i], priv);
 238         }
 239         return 0;
 240
 241 cleanup:
 242         for (--i; i>=0; --i) {
 243                 priv = usb_get_serial_port_data(serial->port[i]);
 244                 pl2303_buf_free(priv->buf);
 245                 kfree(priv);
 246                 usb_set_serial_port_data(serial->port[i], NULL);
 247         }
 248         return -ENOMEM;
 249 }
 250
 251 static int set_control_lines (struct usb_device *dev, u8 value)
 252 {
 253         int retval;
 254
 255         retval = usb_control_msg (dev, usb_sndctrlpipe (dev, 0),
 256                                   SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
 257                                   value, 0, NULL, 0, 100);
 258         dbg("%s - value = %d, retval = %d", __FUNCTION__, value, retval);
 259         return retval;
 260 }
 261
 262 static int pl2303_write (struct usb_serial_port *port,  const unsigned char *buf, 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, port->write_urb->transfer_buffer);
 309
 310         port->write_urb->transfer_buffer_length = count;
 311         port->write_urb->dev = port->serial->dev;
 312         result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
 313         if (result) {
 314                 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
 315                 priv->write_urb_in_use = 0;
 316                 // TODO: reschedule pl2303_send
 317         }
 318
 319         usb_serial_port_softint(port);
 320 }
 321
 322 static int pl2303_write_room(struct usb_serial_port *port)
 323 {
 324         struct pl2303_private *priv = usb_get_serial_port_data(port);
 325         int room = 0;
 326         unsigned long flags;
 327
 328         dbg("%s - port %d", __FUNCTION__, port->number);
 329
 330         spin_lock_irqsave(&priv->lock, flags);
 331         room = pl2303_buf_space_avail(priv->buf);
 332         spin_unlock_irqrestore(&priv->lock, flags);
 333
 334         dbg("%s - returns %d", __FUNCTION__, room);
 335         return room;
 336 }
 337
 338 static int pl2303_chars_in_buffer(struct usb_serial_port *port)
 339 {
 340         struct pl2303_private *priv = usb_get_serial_port_data(port);
 341         int chars = 0;
 342         unsigned long flags;
 343
 344         dbg("%s - port %d", __FUNCTION__, port->number);
 345
 346         spin_lock_irqsave(&priv->lock, flags);
 347         chars = pl2303_buf_data_avail(priv->buf);
 348         spin_unlock_irqrestore(&priv->lock, flags);
 349
 350         dbg("%s - returns %d", __FUNCTION__, chars);
 351         return chars;
 352 }
 353
 354 static void pl2303_set_termios (struct usb_serial_port *port, struct termios *old_termios)
 355 {
 356         struct usb_serial *serial = port->serial;
 357         struct pl2303_private *priv = usb_get_serial_port_data(port);
 358         unsigned long flags;
 359         unsigned int cflag;
 360         unsigned char *buf;
 361         int baud;
 362         int i;
 363         u8 control;
 364
 365         dbg("%s -  port %d", __FUNCTION__, port->number);
 366
 367         if ((!port->tty) || (!port->tty->termios)) {
 368                 dbg("%s - no tty structures", __FUNCTION__);
 369                 return;
 370         }
 371
 372         spin_lock_irqsave(&priv->lock, flags);
 373         if (!priv->termios_initialized) {
 374                 *(port->tty->termios) = tty_std_termios;
 375                 port->tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 376                 priv->termios_initialized = 1;
 377         }
 378         spin_unlock_irqrestore(&priv->lock, flags);
 379
 380         cflag = port->tty->termios->c_cflag;
 381         /* check that they really want us to change something */
 382         if (old_termios) {
 383                 if ((cflag == old_termios->c_cflag) &&
 384                     (RELEVANT_IFLAG(port->tty->termios->c_iflag) == RELEVANT_IFLAG(old_termios->c_iflag))) {
 385                     dbg("%s - nothing to change...", __FUNCTION__);
 386                     return;
 387                 }
 388         }
 389
 390         buf = kzalloc (7, GFP_KERNEL);
 391         if (!buf) {
 392                 dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__);
 393                 return;
 394         }
 395
 396         i = usb_control_msg (serial->dev, usb_rcvctrlpipe (serial->dev, 0),
 397                              GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
 398                              0, 0, buf, 7, 100);
 399         dbg ("0xa1:0x21:0:0  %d - %x %x %x %x %x %x %x", i,
 400              buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6]);
 401
 402
 403         if (cflag & CSIZE) {
 404                 switch (cflag & CSIZE) {
 405                         case CS5:       buf[6] = 5;     break;
 406                         case CS6:       buf[6] = 6;     break;
 407                         case CS7:       buf[6] = 7;     break;
 408                         default:
 409                         case CS8:       buf[6] = 8;     break;
 410                 }
 411                 dbg("%s - data bits = %d", __FUNCTION__, buf[6]);
 412         }
 413
 414         baud = 0;
 415         switch (cflag & CBAUD) {
 416                 case B0:        baud = 0;       break;
 417                 case B75:       baud = 75;      break;
 418                 case B150:      baud = 150;     break;
 419                 case B300:      baud = 300;     break;
 420                 case B600:      baud = 600;     break;
 421                 case B1200:     baud = 1200;    break;
 422                 case B1800:     baud = 1800;    break;
 423                 case B2400:     baud = 2400;    break;
 424                 case B4800:     baud = 4800;    break;
 425                 case B9600:     baud = 9600;    break;
 426                 case B19200:    baud = 19200;   break;
 427                 case B38400:    baud = 38400;   break;
 428                 case B57600:    baud = 57600;   break;
 429                 case B115200:   baud = 115200;  break;
 430                 case B230400:   baud = 230400;  break;
 431                 case B460800:   baud = 460800;  break;
 432                 default:
 433                         dev_err(&port->dev, "pl2303 driver does not support the baudrate requested (fix it)\n");
 434                         break;
 435         }
 436         dbg("%s - baud = %d", __FUNCTION__, baud);
 437         if (baud) {
 438                 buf[0] = baud & 0xff;
 439                 buf[1] = (baud >> 8) & 0xff;
 440                 buf[2] = (baud >> 16) & 0xff;
 441                 buf[3] = (baud >> 24) & 0xff;
 442         }
 443
 444         /* For reference buf[4]=0 is 1 stop bits */
 445         /* For reference buf[4]=1 is 1.5 stop bits */
 446         /* For reference buf[4]=2 is 2 stop bits */
 447         if (cflag & CSTOPB) {
 448                 buf[4] = 2;
 449                 dbg("%s - stop bits = 2", __FUNCTION__);
 450         } else {
 451                 buf[4] = 0;
 452                 dbg("%s - stop bits = 1", __FUNCTION__);
 453         }
 454
 455         if (cflag & PARENB) {
 456                 /* For reference buf[5]=0 is none parity */
 457                 /* For reference buf[5]=1 is odd parity */
 458                 /* For reference buf[5]=2 is even parity */
 459                 /* For reference buf[5]=3 is mark parity */
 460                 /* For reference buf[5]=4 is space parity */
 461                 if (cflag & PARODD) {
 462                         buf[5] = 1;
 463                         dbg("%s - parity = odd", __FUNCTION__);
 464                 } else {
 465                         buf[5] = 2;
 466                         dbg("%s - parity = even", __FUNCTION__);
 467                 }
 468         } else {
 469                 buf[5] = 0;
 470                 dbg("%s - parity = none", __FUNCTION__);
 471         }
 472
 473         i = usb_control_msg (serial->dev, usb_sndctrlpipe (serial->dev, 0),
 474                              SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
 475                              0, 0, buf, 7, 100);
 476         dbg ("0x21:0x20:0:0  %d", i);
 477
 478         /* change control lines if we are switching to or from B0 */
 479         spin_lock_irqsave(&priv->lock, flags);
 480         control = priv->line_control;
 481         if ((cflag & CBAUD) == B0)
 482                 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
 483         else
 484                 priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
 485         if (control != priv->line_control) {
 486                 control = priv->line_control;
 487                 spin_unlock_irqrestore(&priv->lock, flags);
 488                 set_control_lines(serial->dev, control);
 489         } else {
 490                 spin_unlock_irqrestore(&priv->lock, flags);
 491         }
 492
 493         buf[0] = buf[1] = buf[2] = buf[3] = buf[4] = buf[5] = buf[6] = 0;
 494
 495         i = usb_control_msg (serial->dev, usb_rcvctrlpipe (serial->dev, 0),
 496                              GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
 497                              0, 0, buf, 7, 100);
 498         dbg ("0xa1:0x21:0:0  %d - %x %x %x %x %x %x %x", i,
 499              buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6]);
 500
 501         if (cflag & CRTSCTS) {
 502                 __u16 index;
 503                 if (priv->type == HX)
 504                         index = 0x61;
 505                 else
 506                         index = 0x41;
 507                 i = usb_control_msg(serial->dev,
 508                                     usb_sndctrlpipe(serial->dev, 0),
 509                                     VENDOR_WRITE_REQUEST,
 510                                     VENDOR_WRITE_REQUEST_TYPE,
 511                                     0x0, index, NULL, 0, 100);
 512                 dbg ("0x40:0x1:0x0:0x%x  %d", index, i);
 513         }
 514
 515         kfree (buf);
 516 }
 517
 518 static int pl2303_open (struct usb_serial_port *port, struct file *filp)
 519 {
 520         struct termios tmp_termios;
 521         struct usb_serial *serial = port->serial;
 522         struct pl2303_private *priv = usb_get_serial_port_data(port);
 523         unsigned char *buf;
 524         int result;
 525
 526         dbg("%s -  port %d", __FUNCTION__, port->number);
 527
 528         if (priv->type != HX) {
 529                 usb_clear_halt(serial->dev, port->write_urb->pipe);
 530                 usb_clear_halt(serial->dev, port->read_urb->pipe);
 531         }
 532
 533         buf = kmalloc(10, GFP_KERNEL);
 534         if (buf==NULL)
 535                 return -ENOMEM;
 536
 537 #define FISH(a,b,c,d)                                                           \
 538         result=usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev,0),     \
 539                                b, a, c, d, buf, 1, 100);                        \
 540         dbg("0x%x:0x%x:0x%x:0x%x  %d - %x",a,b,c,d,result,buf[0]);
 541
 542 #define SOUP(a,b,c,d)                                                           \
 543         result=usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev,0),     \
 544                                b, a, c, d, NULL, 0, 100);                       \
 545         dbg("0x%x:0x%x:0x%x:0x%x  %d",a,b,c,d,result);
 546
 547         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 548         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 0x0404, 0);
 549         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 550         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8383, 0);
 551         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 552         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 0x0404, 1);
 553         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8484, 0);
 554         FISH (VENDOR_READ_REQUEST_TYPE, VENDOR_READ_REQUEST, 0x8383, 0);
 555         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 0, 1);
 556         SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 1, 0);
 557
 558         if (priv->type == HX) {
 559                 /* HX chip */
 560                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 2, 0x44);
 561                 /* reset upstream data pipes */
 562                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 8, 0);
 563                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 9, 0);
 564         } else {
 565                 SOUP (VENDOR_WRITE_REQUEST_TYPE, VENDOR_WRITE_REQUEST, 2, 0x24);
 566         }
 567
 568         kfree(buf);
 569
 570         /* Setup termios */
 571         if (port->tty) {
 572                 pl2303_set_termios (port, &tmp_termios);
 573         }
 574
 575         //FIXME: need to assert RTS and DTR if CRTSCTS off
 576
 577         dbg("%s - submitting read urb", __FUNCTION__);
 578         port->read_urb->dev = serial->dev;
 579         result = usb_submit_urb (port->read_urb, GFP_KERNEL);
 580         if (result) {
 581                 dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
 582                 pl2303_close (port, NULL);
 583                 return -EPROTO;
 584         }
 585
 586         dbg("%s - submitting interrupt urb", __FUNCTION__);
 587         port->interrupt_in_urb->dev = serial->dev;
 588         result = usb_submit_urb (port->interrupt_in_urb, GFP_KERNEL);
 589         if (result) {
 590                 dev_err(&port->dev, "%s - failed submitting interrupt urb, error %d\n", __FUNCTION__, result);
 591                 pl2303_close (port, NULL);
 592                 return -EPROTO;
 593         }
 594         return 0;
 595 }
 596
 597
 598 static void pl2303_close (struct usb_serial_port *port, struct file *filp)
 599 {
 600         struct pl2303_private *priv = usb_get_serial_port_data(port);
 601         unsigned long flags;
 602         unsigned int c_cflag;
 603         int bps;
 604         long timeout;
 605         wait_queue_t wait;
 606
 607         dbg("%s - port %d", __FUNCTION__, port->number);
 608
 609         /* wait for data to drain from the buffer */
 610         spin_lock_irqsave(&priv->lock, flags);
 611         timeout = PL2303_CLOSING_WAIT;
 612         init_waitqueue_entry(&wait, current);
 613         add_wait_queue(&port->tty->write_wait, &wait);
 614         for (;;) {
 615                 set_current_state(TASK_INTERRUPTIBLE);
 616                 if (pl2303_buf_data_avail(priv->buf) == 0
 617                 || timeout == 0 || signal_pending(current)
 618                 || !usb_get_intfdata(port->serial->interface))  /* disconnect */
 619                         break;
 620                 spin_unlock_irqrestore(&priv->lock, flags);
 621                 timeout = schedule_timeout(timeout);
 622                 spin_lock_irqsave(&priv->lock, flags);
 623         }
 624         set_current_state(TASK_RUNNING);
 625         remove_wait_queue(&port->tty->write_wait, &wait);
 626         /* clear out any remaining data in the buffer */
 627         pl2303_buf_clear(priv->buf);
 628         spin_unlock_irqrestore(&priv->lock, flags);
 629
 630         /* wait for characters to drain from the device */
 631         /* (this is long enough for the entire 256 byte */
 632         /* pl2303 hardware buffer to drain with no flow */
 633         /* control for data rates of 1200 bps or more, */
 634         /* for lower rates we should really know how much */
 635         /* data is in the buffer to compute a delay */
 636         /* that is not unnecessarily long) */
 637         bps = tty_get_baud_rate(port->tty);
 638         if (bps > 1200)
 639                 timeout = max((HZ*2560)/bps,HZ/10);
 640         else
 641                 timeout = 2*HZ;
 642         schedule_timeout_interruptible(timeout);
 643
 644         /* shutdown our urbs */
 645         dbg("%s - shutting down urbs", __FUNCTION__);
 646         usb_kill_urb(port->write_urb);
 647         usb_kill_urb(port->read_urb);
 648         usb_kill_urb(port->interrupt_in_urb);
 649
 650         if (port->tty) {
 651                 c_cflag = port->tty->termios->c_cflag;
 652                 if (c_cflag & HUPCL) {
 653                         /* drop DTR and RTS */
 654                         spin_lock_irqsave(&priv->lock, flags);
 655                         priv->line_control = 0;
 656                         spin_unlock_irqrestore (&priv->lock, flags);
 657                         set_control_lines (port->serial->dev, 0);
 658                 }
 659         }
 660 }
 661
 662 static int pl2303_tiocmset (struct usb_serial_port *port, struct file *file,
 663                             unsigned int set, unsigned int clear)
 664 {
 665         struct pl2303_private *priv = usb_get_serial_port_data(port);
 666         unsigned long flags;
 667         u8 control;
 668
 669         if (!usb_get_intfdata(port->serial->interface))
 670                 return -ENODEV;
 671
 672         spin_lock_irqsave (&priv->lock, flags);
 673         if (set & TIOCM_RTS)
 674                 priv->line_control |= CONTROL_RTS;
 675         if (set & TIOCM_DTR)
 676                 priv->line_control |= CONTROL_DTR;
 677         if (clear & TIOCM_RTS)
 678                 priv->line_control &= ~CONTROL_RTS;
 679         if (clear & TIOCM_DTR)
 680                 priv->line_control &= ~CONTROL_DTR;
 681         control = priv->line_control;
 682         spin_unlock_irqrestore (&priv->lock, flags);
 683
 684         return set_control_lines (port->serial->dev, control);
 685 }
 686
 687 static int pl2303_tiocmget (struct usb_serial_port *port, struct file *file)
 688 {
 689         struct pl2303_private *priv = usb_get_serial_port_data(port);
 690         unsigned long flags;
 691         unsigned int mcr;
 692         unsigned int status;
 693         unsigned int result;
 694
 695         dbg("%s (%d)", __FUNCTION__, port->number);
 696
 697         if (!usb_get_intfdata(port->serial->interface))
 698                 return -ENODEV;
 699
 700         spin_lock_irqsave (&priv->lock, flags);
 701         mcr = priv->line_control;
 702         status = priv->line_status;
 703         spin_unlock_irqrestore (&priv->lock, flags);
 704
 705         result = ((mcr & CONTROL_DTR)           ? TIOCM_DTR : 0)
 706                   | ((mcr & CONTROL_RTS)        ? TIOCM_RTS : 0)
 707                   | ((status & UART_CTS)        ? TIOCM_CTS : 0)
 708                   | ((status & UART_DSR)        ? TIOCM_DSR : 0)
 709                   | ((status & UART_RING)       ? TIOCM_RI  : 0)
 710                   | ((status & UART_DCD)        ? TIOCM_CD  : 0);
 711
 712         dbg("%s - result = %x", __FUNCTION__, result);
 713
 714         return result;
 715 }
 716
 717 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
 718 {
 719         struct pl2303_private *priv = usb_get_serial_port_data(port);
 720         unsigned long flags;
 721         unsigned int prevstatus;
 722         unsigned int status;
 723         unsigned int changed;
 724
 725         spin_lock_irqsave (&priv->lock, flags);
 726         prevstatus = priv->line_status;
 727         spin_unlock_irqrestore (&priv->lock, flags);
 728
 729         while (1) {
 730                 interruptible_sleep_on(&priv->delta_msr_wait);
 731                 /* see if a signal did it */
 732                 if (signal_pending(current))
 733                         return -ERESTARTSYS;
 734
 735                 spin_lock_irqsave (&priv->lock, flags);
 736                 status = priv->line_status;
 737                 spin_unlock_irqrestore (&priv->lock, flags);
 738
 739                 changed=prevstatus^status;
 740
 741                 if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
 742                     ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
 743                     ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
 744                     ((arg & TIOCM_CTS) && (changed & UART_CTS)) ) {
 745                         return 0;
 746                 }
 747                 prevstatus = status;
 748         }
 749         /* NOTREACHED */
 750         return 0;
 751 }
 752
 753 static int pl2303_ioctl (struct usb_serial_port *port, struct file *file, unsigned int cmd, unsigned long arg)
 754 {
 755         dbg("%s (%d) cmd = 0x%04x", __FUNCTION__, port->number, cmd);
 756
 757         switch (cmd) {
 758                 case TIOCMIWAIT:
 759                         dbg("%s (%d) TIOCMIWAIT", __FUNCTION__,  port->number);
 760                         return wait_modem_info(port, arg);
 761
 762                 default:
 763                         dbg("%s not supported = 0x%04x", __FUNCTION__, cmd);
 764                         break;
 765         }
 766
 767         return -ENOIOCTLCMD;
 768 }
 769
 770 static void pl2303_break_ctl (struct usb_serial_port *port, int break_state)
 771 {
 772         struct usb_serial *serial = port->serial;
 773         u16 state;
 774         int result;
 775
 776         dbg("%s - port %d", __FUNCTION__, port->number);
 777
 778         if (break_state == 0)
 779                 state = BREAK_OFF;
 780         else
 781                 state = BREAK_ON;
 782         dbg("%s - turning break %s", __FUNCTION__, state==BREAK_OFF ? "off" : "on");
 783
 784         result = usb_control_msg (serial->dev, usb_sndctrlpipe (serial->dev, 0),
 785                                   BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
 786                                   0, NULL, 0, 100);
 787         if (result)
 788                 dbg("%s - error sending break = %d", __FUNCTION__, result);
 789 }
 790
 791
 792 static void pl2303_shutdown (struct usb_serial *serial)
 793 {
 794         int i;
 795         struct pl2303_private *priv;
 796
 797         dbg("%s", __FUNCTION__);
 798
 799         for (i = 0; i < serial->num_ports; ++i) {
 800                 priv = usb_get_serial_port_data(serial->port[i]);
 801                 if (priv) {
 802                         pl2303_buf_free(priv->buf);
 803                         kfree(priv);
 804                         usb_set_serial_port_data(serial->port[i], NULL);
 805                 }
 806         }
 807 }
 808
 809 static void pl2303_update_line_status(struct usb_serial_port *port,
 810                                       unsigned char *data,
 811                                       unsigned int actual_length)
 812 {
 813
 814         struct pl2303_private *priv = usb_get_serial_port_data(port);
 815         unsigned long flags;
 816         u8 status_idx = UART_STATE;
 817         u8 length = UART_STATE + 1;
 818
 819         if ((le16_to_cpu(port->serial->dev->descriptor.idVendor) == SIEMENS_VENDOR_ID) &&
 820             (le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X65 ||
 821              le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_SX1 ||
 822              le16_to_cpu(port->serial->dev->descriptor.idProduct) == SIEMENS_PRODUCT_ID_X75)) {
 823                 length = 1;
 824                 status_idx = 0;
 825         }
 826
 827         if (actual_length < length)
 828                 goto exit;
 829
 830         /* Save off the uart status for others to look at */
 831         spin_lock_irqsave(&priv->lock, flags);
 832         priv->line_status = data[status_idx];
 833         spin_unlock_irqrestore(&priv->lock, flags);
 834         wake_up_interruptible (&priv->delta_msr_wait);
 835
 836 exit:
 837         return;
 838 }
 839
 840 static void pl2303_read_int_callback (struct urb *urb, struct pt_regs *regs)
 841 {
 842         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
 843         unsigned char *data = urb->transfer_buffer;
 844         unsigned int actual_length = urb->actual_length;
 845         int status;
 846
 847         dbg("%s (%d)", __FUNCTION__, port->number);
 848
 849         switch (urb->status) {
 850         case 0:
 851                 /* success */
 852                 break;
 853         case -ECONNRESET:
 854         case -ENOENT:
 855         case -ESHUTDOWN:
 856                 /* this urb is terminated, clean up */
 857                 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
 858                 return;
 859         default:
 860                 dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
 861                 goto exit;
 862         }
 863
 864         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
 865         pl2303_update_line_status(port, data, actual_length);
 866
 867 exit:
 868         status = usb_submit_urb (urb, GFP_ATOMIC);
 869         if (status)
 870                 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed with result %d\n",
 871                         __FUNCTION__, status);
 872 }
 873
 874
 875 static void pl2303_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
 876 {
 877         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
 878         struct pl2303_private *priv = usb_get_serial_port_data(port);
 879         struct tty_struct *tty;
 880         unsigned char *data = urb->transfer_buffer;
 881         unsigned long flags;
 882         int i;
 883         int result;
 884         u8 status;
 885         char tty_flag;
 886
 887         dbg("%s - port %d", __FUNCTION__, port->number);
 888
 889         if (urb->status) {
 890                 dbg("%s - urb->status = %d", __FUNCTION__, urb->status);
 891                 if (!port->open_count) {
 892                         dbg("%s - port is closed, exiting.", __FUNCTION__);
 893                         return;
 894                 }
 895                 if (urb->status == -EPROTO) {
 896                         /* PL2303 mysteriously fails with -EPROTO reschedule the read */
 897                         dbg("%s - caught -EPROTO, resubmitting the urb", __FUNCTION__);
 898                         urb->status = 0;
 899                         urb->dev = port->serial->dev;
 900                         result = usb_submit_urb(urb, GFP_ATOMIC);
 901                         if (result)
 902                                 dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 903                         return;
 904                 }
 905                 dbg("%s - unable to handle the error, exiting.", __FUNCTION__);
 906                 return;
 907         }
 908
 909         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 910
 911         /* get tty_flag from status */
 912         tty_flag = TTY_NORMAL;
 913
 914         spin_lock_irqsave(&priv->lock, flags);
 915         status = priv->line_status;
 916         priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
 917         spin_unlock_irqrestore(&priv->lock, flags);
 918         wake_up_interruptible (&priv->delta_msr_wait);
 919
 920         /* break takes precedence over parity, */
 921         /* which takes precedence over framing errors */
 922         if (status & UART_BREAK_ERROR )
 923                 tty_flag = TTY_BREAK;
 924         else if (status & UART_PARITY_ERROR)
 925                 tty_flag = TTY_PARITY;
 926         else if (status & UART_FRAME_ERROR)
 927                 tty_flag = TTY_FRAME;
 928         dbg("%s - tty_flag = %d", __FUNCTION__, tty_flag);
 929
 930         tty = port->tty;
 931         if (tty && urb->actual_length) {
 932                 tty_buffer_request_room(tty, urb->actual_length + 1);
 933                 /* overrun is special, not associated with a char */
 934                 if (status & UART_OVERRUN_ERROR)
 935                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 936                 for (i = 0; i < urb->actual_length; ++i)
 937                         tty_insert_flip_char (tty, data[i], tty_flag);
 938                 tty_flip_buffer_push (tty);
 939         }
 940
 941         /* Schedule the next read _if_ we are still open */
 942         if (port->open_count) {
 943                 urb->dev = port->serial->dev;
 944                 result = usb_submit_urb(urb, GFP_ATOMIC);
 945                 if (result)
 946                         dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 947         }
 948
 949         return;
 950 }
 951
 952
 953
 954 static void pl2303_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
 955 {
 956         struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
 957         struct pl2303_private *priv = usb_get_serial_port_data(port);
 958         int result;
 959
 960         dbg("%s - port %d", __FUNCTION__, port->number);
 961
 962         switch (urb->status) {
 963         case 0:
 964                 /* success */
 965                 break;
 966         case -ECONNRESET:
 967         case -ENOENT:
 968         case -ESHUTDOWN:
 969                 /* this urb is terminated, clean up */
 970                 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
 971                 priv->write_urb_in_use = 0;
 972                 return;
 973         default:
 974                 /* error in the urb, so we have to resubmit it */
 975                 dbg("%s - Overflow in write", __FUNCTION__);
 976                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
 977                 port->write_urb->transfer_buffer_length = 1;
 978                 port->write_urb->dev = port->serial->dev;
 979                 result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
 980                 if (result)
 981                         dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n", __FUNCTION__, result);
 982                 else
 983                         return;
 984         }
 985
 986         priv->write_urb_in_use = 0;
 987
 988         /* send any buffered data */
 989         pl2303_send(port);
 990 }
 991
 992
 993 /*
 994  * pl2303_buf_alloc
 995  *
 996  * Allocate a circular buffer and all associated memory.
 997  */
 998
 999 static struct pl2303_buf *pl2303_buf_alloc(unsigned int size)
1000 {
1001
1002         struct pl2303_buf *pb;
1003
1004
1005         if (size == 0)
1006                 return NULL;
1007
1008         pb = (struct pl2303_buf *)kmalloc(sizeof(struct pl2303_buf), GFP_KERNEL);
1009         if (pb == NULL)
1010                 return NULL;
1011
1012         pb->buf_buf = kmalloc(size, GFP_KERNEL);
1013         if (pb->buf_buf == NULL) {
1014                 kfree(pb);
1015                 return NULL;
1016         }
1017
1018         pb->buf_size = size;
1019         pb->buf_get = pb->buf_put = pb->buf_buf;
1020
1021         return pb;
1022
1023 }
1024
1025
1026 /*
1027  * pl2303_buf_free
1028  *
1029  * Free the buffer and all associated memory.
1030  */
1031
1032 static void pl2303_buf_free(struct pl2303_buf *pb)
1033 {
1034         if (pb) {
1035                 kfree(pb->buf_buf);
1036                 kfree(pb);
1037         }
1038 }
1039
1040
1041 /*
1042  * pl2303_buf_clear
1043  *
1044  * Clear out all data in the circular buffer.
1045  */
1046
1047 static void pl2303_buf_clear(struct pl2303_buf *pb)
1048 {
1049         if (pb != NULL)
1050                 pb->buf_get = pb->buf_put;
1051                 /* equivalent to a get of all data available */
1052 }
1053
1054
1055 /*
1056  * pl2303_buf_data_avail
1057  *
1058  * Return the number of bytes of data available in the circular
1059  * buffer.
1060  */
1061
1062 static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb)
1063 {
1064         if (pb != NULL)
1065                 return ((pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size);
1066         else
1067                 return 0;
1068 }
1069
1070
1071 /*
1072  * pl2303_buf_space_avail
1073  *
1074  * Return the number of bytes of space available in the circular
1075  * buffer.
1076  */
1077
1078 static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb)
1079 {
1080         if (pb != NULL)
1081                 return ((pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size);
1082         else
1083                 return 0;
1084 }
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
1096 static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
1097         unsigned int count)
1098 {
1099
1100         unsigned int len;
1101
1102
1103         if (pb == NULL)
1104                 return 0;
1105
1106         len  = pl2303_buf_space_avail(pb);
1107         if (count > len)
1108                 count = len;
1109
1110         if (count == 0)
1111                 return 0;
1112
1113         len = pb->buf_buf + pb->buf_size - pb->buf_put;
1114         if (count > len) {
1115                 memcpy(pb->buf_put, buf, len);
1116                 memcpy(pb->buf_buf, buf+len, count - len);
1117                 pb->buf_put = pb->buf_buf + count - len;
1118         } else {
1119                 memcpy(pb->buf_put, buf, count);
1120                 if (count < len)
1121                         pb->buf_put += count;
1122                 else /* count == len */
1123                         pb->buf_put = pb->buf_buf;
1124         }
1125
1126         return count;
1127
1128 }
1129
1130
1131 /*
1132  * pl2303_buf_get
1133  *
1134  * Get data from the circular buffer and copy to the given buffer.
1135  * Restrict to the amount of data available.
1136  *
1137  * Return the number of bytes copied.
1138  */
1139
1140 static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
1141         unsigned int count)
1142 {
1143
1144         unsigned int len;
1145
1146
1147         if (pb == NULL)
1148                 return 0;
1149
1150         len = pl2303_buf_data_avail(pb);
1151         if (count > len)
1152                 count = len;
1153
1154         if (count == 0)
1155                 return 0;
1156
1157         len = pb->buf_buf + pb->buf_size - pb->buf_get;
1158         if (count > len) {
1159                 memcpy(buf, pb->buf_get, len);
1160                 memcpy(buf+len, pb->buf_buf, count - len);
1161                 pb->buf_get = pb->buf_buf + count - len;
1162         } else {
1163                 memcpy(buf, pb->buf_get, count);
1164                 if (count < len)
1165                         pb->buf_get += count;
1166                 else /* count == len */
1167                         pb->buf_get = pb->buf_buf;
1168         }
1169
1170         return count;
1171
1172 }
1173
1174 static int __init pl2303_init (void)
1175 {
1176         int retval;
1177         retval = usb_serial_register(&pl2303_device);
1178         if (retval)
1179                 goto failed_usb_serial_register;
1180         retval = usb_register(&pl2303_driver);
1181         if (retval)
1182                 goto failed_usb_register;
1183         info(DRIVER_DESC);
1184         return 0;
1185 failed_usb_register:
1186         usb_serial_deregister(&pl2303_device);
1187 failed_usb_serial_register:
1188         return retval;
1189 }
1190
1191
1192 static void __exit pl2303_exit (void)
1193 {
1194         usb_deregister (&pl2303_driver);
1195         usb_serial_deregister (&pl2303_device);
1196 }
1197
1198
1199 module_init(pl2303_init);
1200 module_exit(pl2303_exit);
1201
1202 MODULE_DESCRIPTION(DRIVER_DESC);
1203 MODULE_LICENSE("GPL");
1204
1205 module_param(debug, bool, S_IRUGO | S_IWUSR);
1206 MODULE_PARM_DESC(debug, "Debug enabled or not");
1207