git.oblomov.eu Git - linux-2.6/blob - drivers/usb/serial/ti_usb_3410_5052.c

   1 /* vi: ts=8 sw=8
   2  *
   3  * TI 3410/5052 USB Serial Driver
   4  *
   5  * Copyright (C) 2004 Texas Instruments
   6  *
   7  * This driver is based on the Linux io_ti driver, which is
   8  *   Copyright (C) 2000-2002 Inside Out Networks
   9  *   Copyright (C) 2001-2002 Greg Kroah-Hartman
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * For questions or problems with this driver, contact Texas Instruments
  17  * technical support, or Al Borchers <alborchers@steinerpoint.com>, or
  18  * Peter Berger <pberger@brimson.com>.
  19  *
  20  * This driver needs this hotplug script in /etc/hotplug/usb/ti_usb_3410_5052
  21  * or in /etc/hotplug.d/usb/ti_usb_3410_5052.hotplug to set the device
  22  * configuration.
  23  *
  24  * #!/bin/bash
  25  *
  26  * BOOT_CONFIG=1
  27  * ACTIVE_CONFIG=2
  28  *
  29  * if [[ "$ACTION" != "add" ]]
  30  * then
  31  *      exit
  32  * fi
  33  *
  34  * CONFIG_PATH=/sys${DEVPATH%/?*}/bConfigurationValue
  35  *
  36  * if [[ 0`cat $CONFIG_PATH` -ne $BOOT_CONFIG ]]
  37  * then
  38  *      exit
  39  * fi
  40  *
  41  * PRODUCT=${PRODUCT%/?*}               # delete version
  42  * VENDOR_ID=`printf "%d" 0x${PRODUCT%/?*}`
  43  * PRODUCT_ID=`printf "%d" 0x${PRODUCT#*?/}`
  44  *
  45  * PARAM_PATH=/sys/module/ti_usb_3410_5052/parameters
  46  *
  47  * function scan() {
  48  *      s=$1
  49  *      shift
  50  *      for i
  51  *      do
  52  *              if [[ $s -eq $i ]]
  53  *              then
  54  *                      return 0
  55  *              fi
  56  *      done
  57  *      return 1
  58  * }
  59  *
  60  * IFS=$IFS,
  61  *
  62  * if (scan $VENDOR_ID 1105 `cat $PARAM_PATH/vendor_3410` &&
  63  * scan $PRODUCT_ID 13328 `cat $PARAM_PATH/product_3410`) ||
  64  * (scan $VENDOR_ID 1105 `cat $PARAM_PATH/vendor_5052` &&
  65  * scan $PRODUCT_ID 20562 20818 20570 20575 `cat $PARAM_PATH/product_5052`)
  66  * then
  67  *      echo $ACTIVE_CONFIG > $CONFIG_PATH
  68  * fi
  69  */
  70
  71 #include <linux/config.h>
  72 #include <linux/kernel.h>
  73 #include <linux/errno.h>
  74 #include <linux/init.h>
  75 #include <linux/slab.h>
  76 #include <linux/tty.h>
  77 #include <linux/tty_driver.h>
  78 #include <linux/tty_flip.h>
  79 #include <linux/module.h>
  80 #include <linux/spinlock.h>
  81 #include <linux/ioctl.h>
  82 #include <linux/serial.h>
  83 #include <linux/circ_buf.h>
  84 #include <asm/uaccess.h>
  85 #include <asm/semaphore.h>
  86 #include <linux/usb.h>
  87
  88 #include "usb-serial.h"
  89 #include "ti_usb_3410_5052.h"
  90 #include "ti_fw_3410.h"         /* firmware image for 3410 */
  91 #include "ti_fw_5052.h"         /* firmware image for 5052 */
  92
  93
  94 /* Defines */
  95
  96 #define TI_DRIVER_VERSION       "v0.9"
  97 #define TI_DRIVER_AUTHOR        "Al Borchers <alborchers@steinerpoint.com>"
  98 #define TI_DRIVER_DESC          "TI USB 3410/5052 Serial Driver"
  99
 100 #define TI_FIRMWARE_BUF_SIZE    16284
 101
 102 #define TI_WRITE_BUF_SIZE       1024
 103
 104 #define TI_TRANSFER_TIMEOUT     2
 105
 106 #define TI_DEFAULT_LOW_LATENCY  0
 107 #define TI_DEFAULT_CLOSING_WAIT 4000            /* in .01 secs */
 108
 109 /* supported setserial flags */
 110 #define TI_SET_SERIAL_FLAGS     (ASYNC_LOW_LATENCY)
 111
 112 /* read urb states */
 113 #define TI_READ_URB_RUNNING     0
 114 #define TI_READ_URB_STOPPING    1
 115 #define TI_READ_URB_STOPPED     2
 116
 117 #define TI_EXTRA_VID_PID_COUNT  5
 118
 119
 120 /* Structures */
 121
 122 struct ti_port {
 123         int                     tp_is_open;
 124         __u8                    tp_msr;
 125         __u8                    tp_lsr;
 126         __u8                    tp_shadow_mcr;
 127         __u8                    tp_uart_mode;   /* 232 or 485 modes */
 128         unsigned int            tp_uart_base_addr;
 129         int                     tp_flags;
 130         int                     tp_closing_wait;/* in .01 secs */
 131         struct async_icount     tp_icount;
 132         wait_queue_head_t       tp_msr_wait;    /* wait for msr change */
 133         wait_queue_head_t       tp_write_wait;
 134         struct ti_device        *tp_tdev;
 135         struct usb_serial_port  *tp_port;
 136         spinlock_t              tp_lock;
 137         int                     tp_read_urb_state;
 138         int                     tp_write_urb_in_use;
 139         struct circ_buf         *tp_write_buf;
 140 };
 141
 142 struct ti_device {
 143         struct semaphore        td_open_close_sem;
 144         int                     td_open_port_count;
 145         struct usb_serial       *td_serial;
 146         int                     td_is_3410;
 147         int                     td_urb_error;
 148 };
 149
 150
 151 /* Function Declarations */
 152
 153 static int ti_startup(struct usb_serial *serial);
 154 static void ti_shutdown(struct usb_serial *serial);
 155 static int ti_open(struct usb_serial_port *port, struct file *file);
 156 static void ti_close(struct usb_serial_port *port, struct file *file);
 157 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
 158         int count);
 159 static int ti_write_room(struct usb_serial_port *port);
 160 static int ti_chars_in_buffer(struct usb_serial_port *port);
 161 static void ti_throttle(struct usb_serial_port *port);
 162 static void ti_unthrottle(struct usb_serial_port *port);
 163 static int ti_ioctl(struct usb_serial_port *port, struct file *file, unsigned int cmd, unsigned long arg);
 164 static void ti_set_termios(struct usb_serial_port *port,
 165         struct termios *old_termios);
 166 static int ti_tiocmget(struct usb_serial_port *port, struct file *file);
 167 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
 168         unsigned int set, unsigned int clear);
 169 static void ti_break(struct usb_serial_port *port, int break_state);
 170 static void ti_interrupt_callback(struct urb *urb, struct pt_regs *regs);
 171 static void ti_bulk_in_callback(struct urb *urb, struct pt_regs *regs);
 172 static void ti_bulk_out_callback(struct urb *urb, struct pt_regs *regs);
 173
 174 static void ti_recv(struct device *dev, struct tty_struct *tty,
 175         unsigned char *data, int length);
 176 static void ti_send(struct ti_port *tport);
 177 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
 178 static int ti_get_lsr(struct ti_port *tport);
 179 static int ti_get_serial_info(struct ti_port *tport,
 180         struct serial_struct __user *ret_arg);
 181 static int ti_set_serial_info(struct ti_port *tport,
 182         struct serial_struct __user *new_arg);
 183 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
 184
 185 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
 186
 187 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
 188 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
 189
 190 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
 191         __u16 moduleid, __u16 value, __u8 *data, int size);
 192 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
 193         __u16 moduleid, __u16 value, __u8 *data, int size);
 194
 195 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
 196         __u8 mask, __u8 byte);
 197
 198 static int ti_download_firmware(struct ti_device *tdev,
 199         unsigned char *firmware, unsigned int firmware_size);
 200
 201 /* circular buffer */
 202 static struct circ_buf *ti_buf_alloc(void);
 203 static void ti_buf_free(struct circ_buf *cb);
 204 static void ti_buf_clear(struct circ_buf *cb);
 205 static int ti_buf_data_avail(struct circ_buf *cb);
 206 static int ti_buf_space_avail(struct circ_buf *cb);
 207 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count);
 208 static int ti_buf_get(struct circ_buf *cb, char *buf, int count);
 209
 210
 211 /* Data */
 212
 213 /* module parameters */
 214 static int debug;
 215 static int low_latency = TI_DEFAULT_LOW_LATENCY;
 216 static int closing_wait = TI_DEFAULT_CLOSING_WAIT;
 217 static ushort vendor_3410[TI_EXTRA_VID_PID_COUNT];
 218 static int vendor_3410_count;
 219 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
 220 static int product_3410_count;
 221 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
 222 static int vendor_5052_count;
 223 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
 224 static int product_5052_count;
 225
 226 /* supported devices */
 227 /* the array dimension is the number of default entries plus */
 228 /* TI_EXTRA_VID_PID_COUNT user defined entries plus 1 terminating */
 229 /* null entry */
 230 static struct usb_device_id ti_id_table_3410[1+TI_EXTRA_VID_PID_COUNT+1] = {
 231         { USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
 232 };
 233
 234 static struct usb_device_id ti_id_table_5052[4+TI_EXTRA_VID_PID_COUNT+1] = {
 235         { USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
 236         { USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
 237         { USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
 238         { USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
 239 };
 240
 241 static struct usb_device_id ti_id_table_combined[] = {
 242         { USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
 243         { USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
 244         { USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
 245         { USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
 246         { USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
 247         { }
 248 };
 249
 250 static struct usb_driver ti_usb_driver = {
 251         .owner                  = THIS_MODULE,
 252         .name                   = "ti_usb_3410_5052",
 253         .probe                  = usb_serial_probe,
 254         .disconnect             = usb_serial_disconnect,
 255         .id_table               = ti_id_table_combined,
 256 };
 257
 258 static struct usb_serial_device_type ti_1port_device = {
 259         .owner                  = THIS_MODULE,
 260         .name                   = "TI USB 3410 1 port adapter",
 261         .id_table               = ti_id_table_3410,
 262         .num_interrupt_in       = 1,
 263         .num_bulk_in            = 1,
 264         .num_bulk_out           = 1,
 265         .num_ports              = 1,
 266         .attach                 = ti_startup,
 267         .shutdown               = ti_shutdown,
 268         .open                   = ti_open,
 269         .close                  = ti_close,
 270         .write                  = ti_write,
 271         .write_room             = ti_write_room,
 272         .chars_in_buffer        = ti_chars_in_buffer,
 273         .throttle               = ti_throttle,
 274         .unthrottle             = ti_unthrottle,
 275         .ioctl                  = ti_ioctl,
 276         .set_termios            = ti_set_termios,
 277         .tiocmget               = ti_tiocmget,
 278         .tiocmset               = ti_tiocmset,
 279         .break_ctl              = ti_break,
 280         .read_int_callback      = ti_interrupt_callback,
 281         .read_bulk_callback     = ti_bulk_in_callback,
 282         .write_bulk_callback    = ti_bulk_out_callback,
 283 };
 284
 285 static struct usb_serial_device_type ti_2port_device = {
 286         .owner                  = THIS_MODULE,
 287         .name                   = "TI USB 5052 2 port adapter",
 288         .id_table               = ti_id_table_5052,
 289         .num_interrupt_in       = 1,
 290         .num_bulk_in            = 2,
 291         .num_bulk_out           = 2,
 292         .num_ports              = 2,
 293         .attach                 = ti_startup,
 294         .shutdown               = ti_shutdown,
 295         .open                   = ti_open,
 296         .close                  = ti_close,
 297         .write                  = ti_write,
 298         .write_room             = ti_write_room,
 299         .chars_in_buffer        = ti_chars_in_buffer,
 300         .throttle               = ti_throttle,
 301         .unthrottle             = ti_unthrottle,
 302         .ioctl                  = ti_ioctl,
 303         .set_termios            = ti_set_termios,
 304         .tiocmget               = ti_tiocmget,
 305         .tiocmset               = ti_tiocmset,
 306         .break_ctl              = ti_break,
 307         .read_int_callback      = ti_interrupt_callback,
 308         .read_bulk_callback     = ti_bulk_in_callback,
 309         .write_bulk_callback    = ti_bulk_out_callback,
 310 };
 311
 312
 313 /* Module */
 314
 315 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
 316 MODULE_DESCRIPTION(TI_DRIVER_DESC);
 317 MODULE_VERSION(TI_DRIVER_VERSION);
 318 MODULE_LICENSE("GPL");
 319
 320 module_param(debug, bool, S_IRUGO | S_IWUSR);
 321 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
 322
 323 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
 324 MODULE_PARM_DESC(low_latency, "TTY low_latency flag, 0=off, 1=on, default is off");
 325
 326 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
 327 MODULE_PARM_DESC(closing_wait, "Maximum wait for data to drain in close, in .01 secs, default is 4000");
 328
 329 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
 330 MODULE_PARM_DESC(vendor_3410, "Vendor ids for 3410 based devices, 1-5 short integers");
 331 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
 332 MODULE_PARM_DESC(product_3410, "Product ids for 3410 based devices, 1-5 short integers");
 333 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
 334 MODULE_PARM_DESC(vendor_5052, "Vendor ids for 5052 based devices, 1-5 short integers");
 335 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
 336 MODULE_PARM_DESC(product_5052, "Product ids for 5052 based devices, 1-5 short integers");
 337
 338 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
 339
 340
 341 /* Functions */
 342
 343 static int __init ti_init(void)
 344 {
 345         int i,j;
 346         int ret;
 347
 348
 349         /* insert extra vendor and product ids */
 350         j = sizeof(ti_id_table_3410)/sizeof(struct usb_device_id)
 351                 - TI_EXTRA_VID_PID_COUNT - 1;
 352         for (i=0; i<min(vendor_3410_count,product_3410_count); i++,j++) {
 353                 ti_id_table_3410[j].idVendor = vendor_3410[i];
 354                 ti_id_table_3410[j].idProduct = product_3410[i];
 355                 ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 356         }
 357         j = sizeof(ti_id_table_5052)/sizeof(struct usb_device_id)
 358                 - TI_EXTRA_VID_PID_COUNT - 1;
 359         for (i=0; i<min(vendor_5052_count,product_5052_count); i++,j++) {
 360                 ti_id_table_5052[j].idVendor = vendor_5052[i];
 361                 ti_id_table_5052[j].idProduct = product_5052[i];
 362                 ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 363         }
 364
 365         ret = usb_serial_register(&ti_1port_device);
 366         if (ret)
 367                 goto failed_1port;
 368         ret = usb_serial_register(&ti_2port_device);
 369         if (ret)
 370                 goto failed_2port;
 371
 372         ret = usb_register(&ti_usb_driver);
 373         if (ret)
 374                 goto failed_usb;
 375
 376         info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
 377
 378         return 0;
 379
 380 failed_usb:
 381         usb_serial_deregister(&ti_2port_device);
 382 failed_2port:
 383         usb_serial_deregister(&ti_1port_device);
 384 failed_1port:
 385         return ret;
 386 }
 387
 388
 389 static void __exit ti_exit(void)
 390 {
 391         usb_serial_deregister(&ti_1port_device);
 392         usb_serial_deregister(&ti_2port_device);
 393         usb_deregister(&ti_usb_driver);
 394 }
 395
 396
 397 module_init(ti_init);
 398 module_exit(ti_exit);
 399
 400
 401 static int ti_startup(struct usb_serial *serial)
 402 {
 403         struct ti_device *tdev;
 404         struct ti_port *tport;
 405         struct usb_device *dev = serial->dev;
 406         int status;
 407         int i;
 408
 409
 410         dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
 411             __FUNCTION__, le16_to_cpu(dev->descriptor.idProduct),
 412             dev->descriptor.bNumConfigurations,
 413             dev->actconfig->desc.bConfigurationValue);
 414
 415         /* create device structure */
 416         tdev = kmalloc(sizeof(struct ti_device), GFP_KERNEL);
 417         if (tdev == NULL) {
 418                 dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
 419                 return -ENOMEM;
 420         }
 421         memset(tdev, 0, sizeof(struct ti_device));
 422         sema_init(&tdev->td_open_close_sem, 1);
 423         tdev->td_serial = serial;
 424         usb_set_serial_data(serial, tdev);
 425
 426         /* determine device type */
 427         if (usb_match_id(serial->interface, ti_id_table_3410))
 428                 tdev->td_is_3410 = 1;
 429         dbg("%s - device type is %s", __FUNCTION__, tdev->td_is_3410 ? "3410" : "5052");
 430
 431         /* if we have only 1 configuration, download firmware */
 432         if (dev->descriptor.bNumConfigurations == 1) {
 433
 434                 if (tdev->td_is_3410)
 435                         status = ti_download_firmware(tdev, ti_fw_3410,
 436                                 sizeof(ti_fw_3410));
 437                 else
 438                         status = ti_download_firmware(tdev, ti_fw_5052,
 439                                 sizeof(ti_fw_5052));
 440                 if (status)
 441                         goto free_tdev;
 442
 443                 /* 3410 must be reset, 5052 resets itself */
 444                 if (tdev->td_is_3410) {
 445                         msleep_interruptible(100);
 446                         usb_reset_device(dev);
 447                 }
 448
 449                 status = -ENODEV;
 450                 goto free_tdev;
 451         }
 452
 453         /* the second configuration must be set (in sysfs by hotplug script) */
 454         if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
 455                 status = -ENODEV;
 456                 goto free_tdev;
 457         }
 458
 459         /* set up port structures */
 460         for (i = 0; i < serial->num_ports; ++i) {
 461                 tport = kmalloc(sizeof(struct ti_port), GFP_KERNEL);
 462                 if (tport == NULL) {
 463                         dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
 464                         status = -ENOMEM;
 465                         goto free_tports;
 466                 }
 467                 memset(tport, 0, sizeof(struct ti_port));
 468                 spin_lock_init(&tport->tp_lock);
 469                 tport->tp_uart_base_addr = (i == 0 ? TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
 470                 tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
 471                 tport->tp_closing_wait = closing_wait;
 472                 init_waitqueue_head(&tport->tp_msr_wait);
 473                 init_waitqueue_head(&tport->tp_write_wait);
 474                 tport->tp_write_buf = ti_buf_alloc();
 475                 if (tport->tp_write_buf == NULL) {
 476                         dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
 477                         kfree(tport);
 478                         status = -ENOMEM;
 479                         goto free_tports;
 480                 }
 481                 tport->tp_port = serial->port[i];
 482                 tport->tp_tdev = tdev;
 483                 usb_set_serial_port_data(serial->port[i], tport);
 484                 tport->tp_uart_mode = 0;        /* default is RS232 */
 485         }
 486
 487         return 0;
 488
 489 free_tports:
 490         for (--i; i>=0; --i) {
 491                 tport = usb_get_serial_port_data(serial->port[i]);
 492                 ti_buf_free(tport->tp_write_buf);
 493                 kfree(tport);
 494                 usb_set_serial_port_data(serial->port[i], NULL);
 495         }
 496 free_tdev:
 497         kfree(tdev);
 498         usb_set_serial_data(serial, NULL);
 499         return status;
 500 }
 501
 502
 503 static void ti_shutdown(struct usb_serial *serial)
 504 {
 505         int i;
 506         struct ti_device *tdev = usb_get_serial_data(serial);
 507         struct ti_port *tport;
 508
 509         dbg("%s", __FUNCTION__);
 510
 511         for (i=0; i < serial->num_ports; ++i) {
 512                 tport = usb_get_serial_port_data(serial->port[i]);
 513                 if (tport) {
 514                         ti_buf_free(tport->tp_write_buf);
 515                         kfree(tport);
 516                         usb_set_serial_port_data(serial->port[i], NULL);
 517                 }
 518         }
 519
 520         kfree(tdev);
 521         usb_set_serial_data(serial, NULL);
 522 }
 523
 524
 525 static int ti_open(struct usb_serial_port *port, struct file *file)
 526 {
 527         struct ti_port *tport = usb_get_serial_port_data(port);
 528         struct ti_device *tdev;
 529         struct usb_device *dev;
 530         struct urb *urb;
 531         int port_number;
 532         int status;
 533         __u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
 534                              TI_PIPE_TIMEOUT_ENABLE |
 535                              (TI_TRANSFER_TIMEOUT << 2));
 536
 537         dbg("%s - port %d", __FUNCTION__, port->number);
 538
 539         if (tport == NULL)
 540                 return -ENODEV;
 541
 542         dev = port->serial->dev;
 543         tdev = tport->tp_tdev;
 544
 545         /* only one open on any port on a device at a time */
 546         if (down_interruptible(&tdev->td_open_close_sem))
 547                 return -ERESTARTSYS;
 548
 549         if (port->tty)
 550                 port->tty->low_latency =
 551                         (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 552
 553         port_number = port->number - port->serial->minor;
 554
 555         memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
 556
 557         tport->tp_msr = 0;
 558         tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
 559
 560         /* start interrupt urb the first time a port is opened on this device */
 561         if (tdev->td_open_port_count == 0) {
 562                 dbg("%s - start interrupt in urb", __FUNCTION__);
 563                 urb = tdev->td_serial->port[0]->interrupt_in_urb;
 564                 if (!urb) {
 565                         dev_err(&port->dev, "%s - no interrupt urb\n", __FUNCTION__);
 566                         status = -EINVAL;
 567                         goto up_sem;
 568                 }
 569                 urb->complete = ti_interrupt_callback;
 570                 urb->context = tdev;
 571                 urb->dev = dev;
 572                 status = usb_submit_urb(urb, GFP_KERNEL);
 573                 if (status) {
 574                         dev_err(&port->dev, "%s - submit interrupt urb failed, %d\n", __FUNCTION__, status);
 575                         goto up_sem;
 576                 }
 577         }
 578
 579         ti_set_termios(port, NULL);
 580
 581         dbg("%s - sending TI_OPEN_PORT", __FUNCTION__);
 582         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 583                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 584         if (status) {
 585                 dev_err(&port->dev, "%s - cannot send open command, %d\n", __FUNCTION__, status);
 586                 goto unlink_int_urb;
 587         }
 588
 589         dbg("%s - sending TI_START_PORT", __FUNCTION__);
 590         status = ti_command_out_sync(tdev, TI_START_PORT,
 591                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 592         if (status) {
 593                 dev_err(&port->dev, "%s - cannot send start command, %d\n", __FUNCTION__, status);
 594                 goto unlink_int_urb;
 595         }
 596
 597         dbg("%s - sending TI_PURGE_PORT", __FUNCTION__);
 598         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 599                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
 600         if (status) {
 601                 dev_err(&port->dev, "%s - cannot clear input buffers, %d\n", __FUNCTION__, status);
 602                 goto unlink_int_urb;
 603         }
 604         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 605                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
 606         if (status) {
 607                 dev_err(&port->dev, "%s - cannot clear output buffers, %d\n", __FUNCTION__, status);
 608                 goto unlink_int_urb;
 609         }
 610
 611         /* reset the data toggle on the bulk endpoints to work around bug in
 612          * host controllers where things get out of sync some times */
 613         usb_clear_halt(dev, port->write_urb->pipe);
 614         usb_clear_halt(dev, port->read_urb->pipe);
 615
 616         ti_set_termios(port, NULL);
 617
 618         dbg("%s - sending TI_OPEN_PORT (2)", __FUNCTION__);
 619         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 620                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 621         if (status) {
 622                 dev_err(&port->dev, "%s - cannot send open command (2), %d\n", __FUNCTION__, status);
 623                 goto unlink_int_urb;
 624         }
 625
 626         dbg("%s - sending TI_START_PORT (2)", __FUNCTION__);
 627         status = ti_command_out_sync(tdev, TI_START_PORT,
 628                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 629         if (status) {
 630                 dev_err(&port->dev, "%s - cannot send start command (2), %d\n", __FUNCTION__, status);
 631                 goto unlink_int_urb;
 632         }
 633
 634         /* start read urb */
 635         dbg("%s - start read urb", __FUNCTION__);
 636         urb = port->read_urb;
 637         if (!urb) {
 638                 dev_err(&port->dev, "%s - no read urb\n", __FUNCTION__);
 639                 status = -EINVAL;
 640                 goto unlink_int_urb;
 641         }
 642         tport->tp_read_urb_state = TI_READ_URB_RUNNING;
 643         urb->complete = ti_bulk_in_callback;
 644         urb->context = tport;
 645         urb->dev = dev;
 646         status = usb_submit_urb(urb, GFP_KERNEL);
 647         if (status) {
 648                 dev_err(&port->dev, "%s - submit read urb failed, %d\n", __FUNCTION__, status);
 649                 goto unlink_int_urb;
 650         }
 651
 652         tport->tp_is_open = 1;
 653         ++tdev->td_open_port_count;
 654
 655         goto up_sem;
 656
 657 unlink_int_urb:
 658         if (tdev->td_open_port_count == 0)
 659                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 660 up_sem:
 661         up(&tdev->td_open_close_sem);
 662         dbg("%s - exit %d", __FUNCTION__, status);
 663         return status;
 664 }
 665
 666
 667 static void ti_close(struct usb_serial_port *port, struct file *file)
 668 {
 669         struct ti_device *tdev;
 670         struct ti_port *tport;
 671         int port_number;
 672         int status;
 673         int do_up;
 674
 675         dbg("%s - port %d", __FUNCTION__, port->number);
 676
 677         tdev = usb_get_serial_data(port->serial);
 678         tport = usb_get_serial_port_data(port);
 679         if (tdev == NULL || tport == NULL)
 680                 return;
 681
 682         tport->tp_is_open = 0;
 683
 684         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
 685
 686         usb_kill_urb(port->read_urb);
 687         usb_kill_urb(port->write_urb);
 688         tport->tp_write_urb_in_use = 0;
 689
 690         port_number = port->number - port->serial->minor;
 691
 692         dbg("%s - sending TI_CLOSE_PORT", __FUNCTION__);
 693         status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
 694                      (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 695         if (status)
 696                 dev_err(&port->dev, "%s - cannot send close port command, %d\n" , __FUNCTION__, status);
 697
 698         /* if down is interrupted, continue anyway */
 699         do_up = !down_interruptible(&tdev->td_open_close_sem);
 700         --tport->tp_tdev->td_open_port_count;
 701         if (tport->tp_tdev->td_open_port_count <= 0) {
 702                 /* last port is closed, shut down interrupt urb */
 703                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 704                 tport->tp_tdev->td_open_port_count = 0;
 705         }
 706         if (do_up)
 707                 up(&tdev->td_open_close_sem);
 708
 709         dbg("%s - exit", __FUNCTION__);
 710 }
 711
 712
 713 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
 714         int count)
 715 {
 716         struct ti_port *tport = usb_get_serial_port_data(port);
 717         unsigned long flags;
 718
 719         dbg("%s - port %d", __FUNCTION__, port->number);
 720
 721         if (count == 0) {
 722                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 723                 return 0;
 724         }
 725
 726         if (tport == NULL || !tport->tp_is_open)
 727                 return -ENODEV;
 728
 729         spin_lock_irqsave(&tport->tp_lock, flags);
 730         count = ti_buf_put(tport->tp_write_buf, data, count);
 731         spin_unlock_irqrestore(&tport->tp_lock, flags);
 732
 733         ti_send(tport);
 734
 735         return count;
 736 }
 737
 738
 739 static int ti_write_room(struct usb_serial_port *port)
 740 {
 741         struct ti_port *tport = usb_get_serial_port_data(port);
 742         int room = 0;
 743         unsigned long flags;
 744
 745         dbg("%s - port %d", __FUNCTION__, port->number);
 746
 747         if (tport == NULL)
 748                 return -ENODEV;
 749
 750         spin_lock_irqsave(&tport->tp_lock, flags);
 751         room = ti_buf_space_avail(tport->tp_write_buf);
 752         spin_unlock_irqrestore(&tport->tp_lock, flags);
 753
 754         dbg("%s - returns %d", __FUNCTION__, room);
 755         return room;
 756 }
 757
 758
 759 static int ti_chars_in_buffer(struct usb_serial_port *port)
 760 {
 761         struct ti_port *tport = usb_get_serial_port_data(port);
 762         int chars = 0;
 763         unsigned long flags;
 764
 765         dbg("%s - port %d", __FUNCTION__, port->number);
 766
 767         if (tport == NULL)
 768                 return -ENODEV;
 769
 770         spin_lock_irqsave(&tport->tp_lock, flags);
 771         chars = ti_buf_data_avail(tport->tp_write_buf);
 772         spin_unlock_irqrestore(&tport->tp_lock, flags);
 773
 774         dbg("%s - returns %d", __FUNCTION__, chars);
 775         return chars;
 776 }
 777
 778
 779 static void ti_throttle(struct usb_serial_port *port)
 780 {
 781         struct ti_port *tport = usb_get_serial_port_data(port);
 782         struct tty_struct *tty;
 783
 784         dbg("%s - port %d", __FUNCTION__, port->number);
 785
 786         if (tport == NULL)
 787                 return;
 788
 789         tty = port->tty;
 790         if (!tty) {
 791                 dbg("%s - no tty", __FUNCTION__);
 792                 return;
 793         }
 794
 795         if (I_IXOFF(tty) || C_CRTSCTS(tty))
 796                 ti_stop_read(tport, tty);
 797
 798 }
 799
 800
 801 static void ti_unthrottle(struct usb_serial_port *port)
 802 {
 803         struct ti_port *tport = usb_get_serial_port_data(port);
 804         struct tty_struct *tty;
 805         int status;
 806
 807         dbg("%s - port %d", __FUNCTION__, port->number);
 808
 809         if (tport == NULL)
 810                 return;
 811
 812         tty = port->tty;
 813         if (!tty) {
 814                 dbg("%s - no tty", __FUNCTION__);
 815                 return;
 816         }
 817
 818         if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
 819                 status = ti_restart_read(tport, tty);
 820                 if (status)
 821                         dev_err(&port->dev, "%s - cannot restart read, %d\n", __FUNCTION__, status);
 822         }
 823 }
 824
 825
 826 static int ti_ioctl(struct usb_serial_port *port, struct file *file,
 827         unsigned int cmd, unsigned long arg)
 828 {
 829         struct ti_port *tport = usb_get_serial_port_data(port);
 830         struct async_icount cnow;
 831         struct async_icount cprev;
 832
 833         dbg("%s - port %d, cmd = 0x%04X", __FUNCTION__, port->number, cmd);
 834
 835         if (tport == NULL)
 836                 return -ENODEV;
 837
 838         switch (cmd) {
 839                 case TIOCGSERIAL:
 840                         dbg("%s - (%d) TIOCGSERIAL", __FUNCTION__, port->number);
 841                         return ti_get_serial_info(tport, (struct serial_struct __user *)arg);
 842                         break;
 843
 844                 case TIOCSSERIAL:
 845                         dbg("%s - (%d) TIOCSSERIAL", __FUNCTION__, port->number);
 846                         return ti_set_serial_info(tport, (struct serial_struct __user *)arg);
 847                         break;
 848
 849                 case TIOCMIWAIT:
 850                         dbg("%s - (%d) TIOCMIWAIT", __FUNCTION__, port->number);
 851                         cprev = tport->tp_icount;
 852                         while (1) {
 853                                 interruptible_sleep_on(&tport->tp_msr_wait);
 854                                 if (signal_pending(current))
 855                                         return -ERESTARTSYS;
 856                                 cnow = tport->tp_icount;
 857                                 if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
 858                                     cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
 859                                         return -EIO; /* no change => error */
 860                                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 861                                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 862                                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
 863                                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
 864                                         return 0;
 865                                 }
 866                                 cprev = cnow;
 867                         }
 868                         break;
 869
 870                 case TIOCGICOUNT:
 871                         dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__, port->number, tport->tp_icount.rx, tport->tp_icount.tx);
 872                         if (copy_to_user((void __user *)arg, &tport->tp_icount, sizeof(tport->tp_icount)))
 873                                 return -EFAULT;
 874                         return 0;
 875         }
 876
 877         return -ENOIOCTLCMD;
 878 }
 879
 880
 881 static void ti_set_termios(struct usb_serial_port *port,
 882         struct termios *old_termios)
 883 {
 884         struct ti_port *tport = usb_get_serial_port_data(port);
 885         struct tty_struct *tty = port->tty;
 886         struct ti_uart_config *config;
 887         tcflag_t cflag,iflag;
 888         int baud;
 889         int status;
 890         int port_number = port->number - port->serial->minor;
 891         unsigned int mcr;
 892
 893         dbg("%s - port %d", __FUNCTION__, port->number);
 894
 895         if (!tty || !tty->termios) {
 896                 dbg("%s - no tty or termios", __FUNCTION__);
 897                 return;
 898         }
 899
 900         cflag = tty->termios->c_cflag;
 901         iflag = tty->termios->c_iflag;
 902
 903         if (old_termios && cflag == old_termios->c_cflag
 904         && iflag == old_termios->c_iflag) {
 905                 dbg("%s - nothing to change", __FUNCTION__);
 906                 return;
 907         }
 908
 909         dbg("%s - clfag %08x, iflag %08x", __FUNCTION__, cflag, iflag);
 910
 911         if (old_termios)
 912                 dbg("%s - old clfag %08x, old iflag %08x", __FUNCTION__, old_termios->c_cflag, old_termios->c_iflag);
 913
 914         if (tport == NULL)
 915                 return;
 916
 917         config = kmalloc(sizeof(*config), GFP_KERNEL);
 918         if (!config) {
 919                 dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
 920                 return;
 921         }
 922
 923         config->wFlags = 0;
 924
 925         /* these flags must be set */
 926         config->wFlags |= TI_UART_ENABLE_MS_INTS;
 927         config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
 928         config->bUartMode = (__u8)(tport->tp_uart_mode);
 929
 930         switch (cflag & CSIZE) {
 931                 case CS5:
 932                             config->bDataBits = TI_UART_5_DATA_BITS;
 933                             break;
 934                 case CS6:
 935                             config->bDataBits = TI_UART_6_DATA_BITS;
 936                             break;
 937                 case CS7:
 938                             config->bDataBits = TI_UART_7_DATA_BITS;
 939                             break;
 940                 default:
 941                 case CS8:
 942                             config->bDataBits = TI_UART_8_DATA_BITS;
 943                             break;
 944         }
 945
 946         if (cflag & PARENB) {
 947                 if (cflag & PARODD) {
 948                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 949                         config->bParity = TI_UART_ODD_PARITY;
 950                 } else {
 951                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 952                         config->bParity = TI_UART_EVEN_PARITY;
 953                 }
 954         } else {
 955                 config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
 956                 config->bParity = TI_UART_NO_PARITY;
 957         }
 958
 959         if (cflag & CSTOPB)
 960                 config->bStopBits = TI_UART_2_STOP_BITS;
 961         else
 962                 config->bStopBits = TI_UART_1_STOP_BITS;
 963
 964         if (cflag & CRTSCTS) {
 965                 /* RTS flow control must be off to drop RTS for baud rate B0 */
 966                 if ((cflag & CBAUD) != B0)
 967                         config->wFlags |= TI_UART_ENABLE_RTS_IN;
 968                 config->wFlags |= TI_UART_ENABLE_CTS_OUT;
 969         } else {
 970                 tty->hw_stopped = 0;
 971                 ti_restart_read(tport, tty);
 972         }
 973
 974         if (I_IXOFF(tty) || I_IXON(tty)) {
 975                 config->cXon  = START_CHAR(tty);
 976                 config->cXoff = STOP_CHAR(tty);
 977
 978                 if (I_IXOFF(tty))
 979                         config->wFlags |= TI_UART_ENABLE_X_IN;
 980                 else
 981                         ti_restart_read(tport, tty);
 982
 983                 if (I_IXON(tty))
 984                         config->wFlags |= TI_UART_ENABLE_X_OUT;
 985         }
 986
 987         baud = tty_get_baud_rate(tty);
 988         if (!baud) baud = 9600;
 989         if (tport->tp_tdev->td_is_3410)
 990                 config->wBaudRate = (__u16)((923077 + baud/2) / baud);
 991         else
 992                 config->wBaudRate = (__u16)((461538 + baud/2) / baud);
 993
 994         dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
 995         __FUNCTION__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
 996
 997         cpu_to_be16s(&config->wBaudRate);
 998         cpu_to_be16s(&config->wFlags);
 999
1000         status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1001                 (__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1002                 sizeof(*config));
1003         if (status)
1004                 dev_err(&port->dev, "%s - cannot set config on port %d, %d\n", __FUNCTION__, port_number, status);
1005
1006         /* SET_CONFIG asserts RTS and DTR, reset them correctly */
1007         mcr = tport->tp_shadow_mcr;
1008         /* if baud rate is B0, clear RTS and DTR */
1009         if ((cflag & CBAUD) == B0)
1010                 mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1011         status = ti_set_mcr(tport, mcr);
1012         if (status)
1013                 dev_err(&port->dev, "%s - cannot set modem control on port %d, %d\n", __FUNCTION__, port_number, status);
1014
1015         kfree(config);
1016 }
1017
1018
1019 static int ti_tiocmget(struct usb_serial_port *port, struct file *file)
1020 {
1021         struct ti_port *tport = usb_get_serial_port_data(port);
1022         unsigned int result;
1023         unsigned int msr;
1024         unsigned int mcr;
1025
1026         dbg("%s - port %d", __FUNCTION__, port->number);
1027
1028         if (tport == NULL)
1029                 return -ENODEV;
1030
1031         msr = tport->tp_msr;
1032         mcr = tport->tp_shadow_mcr;
1033
1034         result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1035                 | ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1036                 | ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1037                 | ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1038                 | ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1039                 | ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1040                 | ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1041
1042         dbg("%s - 0x%04X", __FUNCTION__, result);
1043
1044         return result;
1045 }
1046
1047
1048 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
1049         unsigned int set, unsigned int clear)
1050 {
1051         struct ti_port *tport = usb_get_serial_port_data(port);
1052         unsigned int mcr;
1053
1054         dbg("%s - port %d", __FUNCTION__, port->number);
1055
1056         if (tport == NULL)
1057                 return -ENODEV;
1058
1059         mcr = tport->tp_shadow_mcr;
1060
1061         if (set & TIOCM_RTS)
1062                 mcr |= TI_MCR_RTS;
1063         if (set & TIOCM_DTR)
1064                 mcr |= TI_MCR_DTR;
1065         if (set & TIOCM_LOOP)
1066                 mcr |= TI_MCR_LOOP;
1067
1068         if (clear & TIOCM_RTS)
1069                 mcr &= ~TI_MCR_RTS;
1070         if (clear & TIOCM_DTR)
1071                 mcr &= ~TI_MCR_DTR;
1072         if (clear & TIOCM_LOOP)
1073                 mcr &= ~TI_MCR_LOOP;
1074
1075         return ti_set_mcr(tport, mcr);
1076 }
1077
1078
1079 static void ti_break(struct usb_serial_port *port, int break_state)
1080 {
1081         struct ti_port *tport = usb_get_serial_port_data(port);
1082         int status;
1083
1084         dbg("%s - state = %d", __FUNCTION__, break_state);
1085
1086         if (tport == NULL)
1087                 return;
1088
1089         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1090
1091         status = ti_write_byte(tport->tp_tdev,
1092                 tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1093                 TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1094
1095         if (status)
1096                 dbg("%s - error setting break, %d", __FUNCTION__, status);
1097 }
1098
1099
1100 static void ti_interrupt_callback(struct urb *urb, struct pt_regs *regs)
1101 {
1102         struct ti_device *tdev = (struct ti_device *)urb->context;
1103         struct usb_serial_port *port;
1104         struct usb_serial *serial = tdev->td_serial;
1105         struct ti_port *tport;
1106         struct device *dev = &urb->dev->dev;
1107         unsigned char *data = urb->transfer_buffer;
1108         int length = urb->actual_length;
1109         int port_number;
1110         int function;
1111         int status;
1112         __u8 msr;
1113
1114         dbg("%s", __FUNCTION__);
1115
1116         switch (urb->status) {
1117         case 0:
1118                 break;
1119         case -ECONNRESET:
1120         case -ENOENT:
1121         case -ESHUTDOWN:
1122                 dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1123                 tdev->td_urb_error = 1;
1124                 return;
1125         default:
1126                 dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status);
1127                 tdev->td_urb_error = 1;
1128                 goto exit;
1129         }
1130
1131         if (length != 2) {
1132                 dbg("%s - bad packet size, %d", __FUNCTION__, length);
1133                 goto exit;
1134         }
1135
1136         if (data[0] == TI_CODE_HARDWARE_ERROR) {
1137                 dev_err(dev, "%s - hardware error, %d\n", __FUNCTION__, data[1]);
1138                 goto exit;
1139         }
1140
1141         port_number = TI_GET_PORT_FROM_CODE(data[0]);
1142         function = TI_GET_FUNC_FROM_CODE(data[0]);
1143
1144         dbg("%s - port_number %d, function %d, data 0x%02X", __FUNCTION__, port_number, function, data[1]);
1145
1146         if (port_number >= serial->num_ports) {
1147                 dev_err(dev, "%s - bad port number, %d\n", __FUNCTION__, port_number);
1148                 goto exit;
1149         }
1150
1151         port = serial->port[port_number];
1152
1153         tport = usb_get_serial_port_data(port);
1154         if (!tport)
1155                 goto exit;
1156
1157         switch (function) {
1158         case TI_CODE_DATA_ERROR:
1159                 dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n", __FUNCTION__, port_number, data[1]);
1160                 break;
1161
1162         case TI_CODE_MODEM_STATUS:
1163                 msr = data[1];
1164                 dbg("%s - port %d, msr 0x%02X", __FUNCTION__, port_number, msr);
1165                 ti_handle_new_msr(tport, msr);
1166                 break;
1167
1168         default:
1169                 dev_err(dev, "%s - unknown interrupt code, 0x%02X\n", __FUNCTION__, data[1]);
1170                 break;
1171         }
1172
1173 exit:
1174         status = usb_submit_urb(urb, GFP_ATOMIC);
1175         if (status)
1176                 dev_err(dev, "%s - resubmit interrupt urb failed, %d\n", __FUNCTION__, status);
1177 }
1178
1179
1180 static void ti_bulk_in_callback(struct urb *urb, struct pt_regs *regs)
1181 {
1182         struct ti_port *tport = (struct ti_port *)urb->context;
1183         struct usb_serial_port *port = tport->tp_port;
1184         struct device *dev = &urb->dev->dev;
1185         int status = 0;
1186
1187         dbg("%s", __FUNCTION__);
1188
1189         switch (urb->status) {
1190         case 0:
1191                 break;
1192         case -ECONNRESET:
1193         case -ENOENT:
1194         case -ESHUTDOWN:
1195                 dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1196                 tport->tp_tdev->td_urb_error = 1;
1197                 wake_up_interruptible(&tport->tp_write_wait);
1198                 return;
1199         default:
1200                 dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status );
1201                 tport->tp_tdev->td_urb_error = 1;
1202                 wake_up_interruptible(&tport->tp_write_wait);
1203         }
1204
1205         if (urb->status == -EPIPE)
1206                 goto exit;
1207
1208         if (urb->status) {
1209                 dev_err(dev, "%s - stopping read!\n", __FUNCTION__);
1210                 return;
1211         }
1212
1213         if (port->tty && urb->actual_length) {
1214                 usb_serial_debug_data(debug, dev, __FUNCTION__,
1215                         urb->actual_length, urb->transfer_buffer);
1216
1217                 if (!tport->tp_is_open)
1218                         dbg("%s - port closed, dropping data", __FUNCTION__);
1219                 else
1220                         ti_recv(&urb->dev->dev, port->tty, urb->transfer_buffer,
1221                                 urb->actual_length);
1222
1223                 spin_lock(&tport->tp_lock);
1224                 tport->tp_icount.rx += urb->actual_length;
1225                 spin_unlock(&tport->tp_lock);
1226         }
1227
1228 exit:
1229         /* continue to read unless stopping */
1230         spin_lock(&tport->tp_lock);
1231         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1232                 urb->dev = port->serial->dev;
1233                 status = usb_submit_urb(urb, GFP_ATOMIC);
1234         } else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1235                 tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1236         }
1237         spin_unlock(&tport->tp_lock);
1238         if (status)
1239                 dev_err(dev, "%s - resubmit read urb failed, %d\n", __FUNCTION__, status);
1240 }
1241
1242
1243 static void ti_bulk_out_callback(struct urb *urb, struct pt_regs *regs)
1244 {
1245         struct ti_port *tport = (struct ti_port *)urb->context;
1246         struct usb_serial_port *port = tport->tp_port;
1247         struct device *dev = &urb->dev->dev;
1248
1249         dbg("%s - port %d", __FUNCTION__, port->number);
1250
1251         tport->tp_write_urb_in_use = 0;
1252
1253         switch (urb->status) {
1254         case 0:
1255                 break;
1256         case -ECONNRESET:
1257         case -ENOENT:
1258         case -ESHUTDOWN:
1259                 dbg("%s - urb shutting down, %d", __FUNCTION__, urb->status);
1260                 tport->tp_tdev->td_urb_error = 1;
1261                 wake_up_interruptible(&tport->tp_write_wait);
1262                 return;
1263         default:
1264                 dev_err(dev, "%s - nonzero urb status, %d\n", __FUNCTION__, urb->status);
1265                 tport->tp_tdev->td_urb_error = 1;
1266                 wake_up_interruptible(&tport->tp_write_wait);
1267         }
1268
1269         /* send any buffered data */
1270         ti_send(tport);
1271 }
1272
1273
1274 static void ti_recv(struct device *dev, struct tty_struct *tty,
1275         unsigned char *data, int length)
1276 {
1277         int cnt;
1278
1279         do {
1280                 if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1281                         tty_flip_buffer_push(tty);
1282                         if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
1283                                 dev_err(dev, "%s - dropping data, %d bytes lost\n", __FUNCTION__, length);
1284                                 return;
1285                         }
1286                 }
1287                 cnt = min(length, TTY_FLIPBUF_SIZE - tty->flip.count);
1288                 memcpy(tty->flip.char_buf_ptr, data, cnt);
1289                 memset(tty->flip.flag_buf_ptr, 0, cnt);
1290                 tty->flip.char_buf_ptr += cnt;
1291                 tty->flip.flag_buf_ptr += cnt;
1292                 tty->flip.count += cnt;
1293                 data += cnt;
1294                 length -= cnt;
1295         } while (length > 0);
1296
1297         tty_flip_buffer_push(tty);
1298 }
1299
1300
1301 static void ti_send(struct ti_port *tport)
1302 {
1303         int count, result;
1304         struct usb_serial_port *port = tport->tp_port;
1305         struct tty_struct *tty = port->tty;
1306         unsigned long flags;
1307
1308
1309         dbg("%s - port %d", __FUNCTION__, port->number);
1310
1311         spin_lock_irqsave(&tport->tp_lock, flags);
1312
1313         if (tport->tp_write_urb_in_use) {
1314                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1315                 return;
1316         }
1317
1318         count = ti_buf_get(tport->tp_write_buf,
1319                                 port->write_urb->transfer_buffer,
1320                                 port->bulk_out_size);
1321
1322         if (count == 0) {
1323                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1324                 return;
1325         }
1326
1327         tport->tp_write_urb_in_use = 1;
1328
1329         spin_unlock_irqrestore(&tport->tp_lock, flags);
1330
1331         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);
1332
1333         usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1334                            usb_sndbulkpipe(port->serial->dev,
1335                                             port->bulk_out_endpointAddress),
1336                            port->write_urb->transfer_buffer, count,
1337                            ti_bulk_out_callback, tport);
1338
1339         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1340         if (result) {
1341                 dev_err(&port->dev, "%s - submit write urb failed, %d\n", __FUNCTION__, result);
1342                 tport->tp_write_urb_in_use = 0;
1343                 /* TODO: reschedule ti_send */
1344         } else {
1345                 spin_lock_irqsave(&tport->tp_lock, flags);
1346                 tport->tp_icount.tx += count;
1347                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1348         }
1349
1350         /* more room in the buffer for new writes, wakeup */
1351         if (tty)
1352                 tty_wakeup(tty);
1353         wake_up_interruptible(&tport->tp_write_wait);
1354 }
1355
1356
1357 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1358 {
1359         int status;
1360
1361         status = ti_write_byte(tport->tp_tdev,
1362                 tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1363                 TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1364
1365         if (!status)
1366                 tport->tp_shadow_mcr = mcr;
1367
1368         return status;
1369 }
1370
1371
1372 static int ti_get_lsr(struct ti_port *tport)
1373 {
1374         int size,status;
1375         struct ti_device *tdev = tport->tp_tdev;
1376         struct usb_serial_port *port = tport->tp_port;
1377         int port_number = port->number - port->serial->minor;
1378         struct ti_port_status *data;
1379
1380         dbg("%s - port %d", __FUNCTION__, port->number);
1381
1382         size = sizeof(struct ti_port_status);
1383         data = kmalloc(size, GFP_KERNEL);
1384         if (!data) {
1385                 dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
1386                 return -ENOMEM;
1387         }
1388
1389         status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1390                 (__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1391         if (status) {
1392                 dev_err(&port->dev, "%s - get port status command failed, %d\n", __FUNCTION__, status);
1393                 goto free_data;
1394         }
1395
1396         dbg("%s - lsr 0x%02X", __FUNCTION__, data->bLSR);
1397
1398         tport->tp_lsr = data->bLSR;
1399
1400 free_data:
1401         kfree(data);
1402         return status;
1403 }
1404
1405
1406 static int ti_get_serial_info(struct ti_port *tport,
1407         struct serial_struct __user *ret_arg)
1408 {
1409         struct usb_serial_port *port = tport->tp_port;
1410         struct serial_struct ret_serial;
1411
1412         if (!ret_arg)
1413                 return -EFAULT;
1414
1415         memset(&ret_serial, 0, sizeof(ret_serial));
1416
1417         ret_serial.type = PORT_16550A;
1418         ret_serial.line = port->serial->minor;
1419         ret_serial.port = port->number - port->serial->minor;
1420         ret_serial.flags = tport->tp_flags;
1421         ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1422         ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1423         ret_serial.closing_wait = tport->tp_closing_wait;
1424
1425         if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1426                 return -EFAULT;
1427
1428         return 0;
1429 }
1430
1431
1432 static int ti_set_serial_info(struct ti_port *tport,
1433         struct serial_struct __user *new_arg)
1434 {
1435         struct usb_serial_port *port = tport->tp_port;
1436         struct serial_struct new_serial;
1437
1438         if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1439                 return -EFAULT;
1440
1441         tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1442         if (port->tty)
1443                 port->tty->low_latency =
1444                         (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1445         tport->tp_closing_wait = new_serial.closing_wait;
1446
1447         return 0;
1448 }
1449
1450
1451 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1452 {
1453         struct async_icount *icount;
1454         struct tty_struct *tty;
1455         unsigned long flags;
1456
1457         dbg("%s - msr 0x%02X", __FUNCTION__, msr);
1458
1459         if (msr & TI_MSR_DELTA_MASK) {
1460                 spin_lock_irqsave(&tport->tp_lock, flags);
1461                 icount = &tport->tp_icount;
1462                 if (msr & TI_MSR_DELTA_CTS)
1463                         icount->cts++;
1464                 if (msr & TI_MSR_DELTA_DSR)
1465                         icount->dsr++;
1466                 if (msr & TI_MSR_DELTA_CD)
1467                         icount->dcd++;
1468                 if (msr & TI_MSR_DELTA_RI)
1469                         icount->rng++;
1470                 wake_up_interruptible(&tport->tp_msr_wait);
1471                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1472         }
1473
1474         tport->tp_msr = msr & TI_MSR_MASK;
1475
1476         /* handle CTS flow control */
1477         tty = tport->tp_port->tty;
1478         if (tty && C_CRTSCTS(tty)) {
1479                 if (msr & TI_MSR_CTS) {
1480                         tty->hw_stopped = 0;
1481                         tty_wakeup(tty);
1482                 } else {
1483                         tty->hw_stopped = 1;
1484                 }
1485         }
1486 }
1487
1488
1489 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1490 {
1491         struct ti_device *tdev = tport->tp_tdev;
1492         struct usb_serial_port *port = tport->tp_port;
1493         wait_queue_t wait;
1494         unsigned long flags;
1495
1496         dbg("%s - port %d", __FUNCTION__, port->number);
1497
1498         spin_lock_irqsave(&tport->tp_lock, flags);
1499
1500         /* wait for data to drain from the buffer */
1501         tdev->td_urb_error = 0;
1502         init_waitqueue_entry(&wait, current);
1503         add_wait_queue(&tport->tp_write_wait, &wait);
1504         for (;;) {
1505                 set_current_state(TASK_INTERRUPTIBLE);
1506                 if (ti_buf_data_avail(tport->tp_write_buf) == 0
1507                 || timeout == 0 || signal_pending(current)
1508                 || tdev->td_urb_error
1509                 || !usb_get_intfdata(port->serial->interface))  /* disconnect */
1510                         break;
1511                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1512                 timeout = schedule_timeout(timeout);
1513                 spin_lock_irqsave(&tport->tp_lock, flags);
1514         }
1515         set_current_state(TASK_RUNNING);
1516         remove_wait_queue(&tport->tp_write_wait, &wait);
1517
1518         /* flush any remaining data in the buffer */
1519         if (flush)
1520                 ti_buf_clear(tport->tp_write_buf);
1521
1522         spin_unlock_irqrestore(&tport->tp_lock, flags);
1523
1524         /* wait for data to drain from the device */
1525         /* wait for empty tx register, plus 20 ms */
1526         timeout += jiffies;
1527         tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1528         while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1529         && !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1530         && usb_get_intfdata(port->serial->interface)) {  /* not disconnected */
1531                 if (ti_get_lsr(tport))
1532                         break;
1533                 msleep_interruptible(20);
1534         }
1535 }
1536
1537
1538 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1539 {
1540         unsigned long flags;
1541
1542         spin_lock_irqsave(&tport->tp_lock, flags);
1543
1544         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1545                 tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1546
1547         spin_unlock_irqrestore(&tport->tp_lock, flags);
1548 }
1549
1550
1551 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1552 {
1553         struct urb *urb;
1554         int status = 0;
1555         unsigned long flags;
1556
1557         spin_lock_irqsave(&tport->tp_lock, flags);
1558
1559         if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1560                 urb = tport->tp_port->read_urb;
1561                 urb->complete = ti_bulk_in_callback;
1562                 urb->context = tport;
1563                 urb->dev = tport->tp_port->serial->dev;
1564                 status = usb_submit_urb(urb, GFP_KERNEL);
1565         }
1566         tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1567
1568         spin_unlock_irqrestore(&tport->tp_lock, flags);
1569
1570         return status;
1571 }
1572
1573
1574 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1575         __u16 moduleid, __u16 value, __u8 *data, int size)
1576 {
1577         int status;
1578
1579         status = usb_control_msg(tdev->td_serial->dev,
1580                 usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1581                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1582                 value, moduleid, data, size, 1000);
1583
1584         if (status == size)
1585                 status = 0;
1586
1587         if (status > 0)
1588                 status = -ECOMM;
1589
1590         return status;
1591 }
1592
1593
1594 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1595         __u16 moduleid, __u16 value, __u8 *data, int size)
1596 {
1597         int status;
1598
1599         status = usb_control_msg(tdev->td_serial->dev,
1600                 usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1601                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1602                 value, moduleid, data, size, 1000);
1603
1604         if (status == size)
1605                 status = 0;
1606
1607         if (status > 0)
1608                 status = -ECOMM;
1609
1610         return status;
1611 }
1612
1613
1614 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1615         __u8 mask, __u8 byte)
1616 {
1617         int status;
1618         unsigned int size;
1619         struct ti_write_data_bytes *data;
1620         struct device *dev = &tdev->td_serial->dev->dev;
1621
1622         dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X", __FUNCTION__, addr, mask, byte);
1623
1624         size = sizeof(struct ti_write_data_bytes) + 2;
1625         data = kmalloc(size, GFP_KERNEL);
1626         if (!data) {
1627                 dev_err(dev, "%s - out of memory\n", __FUNCTION__);
1628                 return -ENOMEM;
1629         }
1630
1631         data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1632         data->bDataType = TI_RW_DATA_BYTE;
1633         data->bDataCounter = 1;
1634         data->wBaseAddrHi = cpu_to_be16(addr>>16);
1635         data->wBaseAddrLo = cpu_to_be16(addr);
1636         data->bData[0] = mask;
1637         data->bData[1] = byte;
1638
1639         status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1640                 (__u8 *)data, size);
1641
1642         if (status < 0)
1643                 dev_err(dev, "%s - failed, %d\n", __FUNCTION__, status);
1644
1645         kfree(data);
1646
1647         return status;
1648 }
1649
1650
1651 static int ti_download_firmware(struct ti_device *tdev,
1652         unsigned char *firmware, unsigned int firmware_size)
1653 {
1654         int status = 0;
1655         int buffer_size;
1656         int pos;
1657         int len;
1658         int done;
1659         __u8 cs = 0;
1660         __u8 *buffer;
1661         struct usb_device *dev = tdev->td_serial->dev;
1662         struct ti_firmware_header *header;
1663         unsigned int pipe = usb_sndbulkpipe(dev,
1664                 tdev->td_serial->port[0]->bulk_out_endpointAddress);
1665
1666
1667         buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1668         buffer = kmalloc(buffer_size, GFP_KERNEL);
1669         if (!buffer) {
1670                 dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
1671                 return -ENOMEM;
1672         }
1673
1674         memcpy(buffer, firmware, firmware_size);
1675         memset(buffer+firmware_size, 0xff, buffer_size-firmware_size);
1676
1677         for(pos = sizeof(struct ti_firmware_header); pos < buffer_size; pos++)
1678                 cs = (__u8)(cs + buffer[pos]);
1679
1680         header = (struct ti_firmware_header *)buffer;
1681         header->wLength = cpu_to_le16((__u16)(buffer_size - sizeof(struct ti_firmware_header)));
1682         header->bCheckSum = cs;
1683
1684         dbg("%s - downloading firmware", __FUNCTION__);
1685         for (pos = 0; pos < buffer_size; pos += done) {
1686                 len = min(buffer_size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1687                 status = usb_bulk_msg(dev, pipe, buffer+pos, len, &done, 1000);
1688                 if (status)
1689                         break;
1690         }
1691
1692         kfree(buffer);
1693
1694         if (status) {
1695                 dev_err(&dev->dev, "%s - error downloading firmware, %d\n", __FUNCTION__, status);
1696                 return status;
1697         }
1698
1699         dbg("%s - download successful", __FUNCTION__);
1700
1701         return 0;
1702 }
1703
1704
1705 /* Circular Buffer Functions */
1706
1707 /*
1708  * ti_buf_alloc
1709  *
1710  * Allocate a circular buffer and all associated memory.
1711  */
1712
1713 static struct circ_buf *ti_buf_alloc(void)
1714 {
1715         struct circ_buf *cb;
1716
1717         cb = (struct circ_buf *)kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1718         if (cb == NULL)
1719                 return NULL;
1720
1721         cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1722         if (cb->buf == NULL) {
1723                 kfree(cb);
1724                 return NULL;
1725         }
1726
1727         ti_buf_clear(cb);
1728
1729         return cb;
1730 }
1731
1732
1733 /*
1734  * ti_buf_free
1735  *
1736  * Free the buffer and all associated memory.
1737  */
1738
1739 static void ti_buf_free(struct circ_buf *cb)
1740 {
1741         kfree(cb->buf);
1742         kfree(cb);
1743 }
1744
1745
1746 /*
1747  * ti_buf_clear
1748  *
1749  * Clear out all data in the circular buffer.
1750  */
1751
1752 static void ti_buf_clear(struct circ_buf *cb)
1753 {
1754         cb->head = cb->tail = 0;
1755 }
1756
1757
1758 /*
1759  * ti_buf_data_avail
1760  *
1761  * Return the number of bytes of data available in the circular
1762  * buffer.
1763  */
1764
1765 static int ti_buf_data_avail(struct circ_buf *cb)
1766 {
1767         return CIRC_CNT(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1768 }
1769
1770
1771 /*
1772  * ti_buf_space_avail
1773  *
1774  * Return the number of bytes of space available in the circular
1775  * buffer.
1776  */
1777
1778 static int ti_buf_space_avail(struct circ_buf *cb)
1779 {
1780         return CIRC_SPACE(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1781 }
1782
1783
1784 /*
1785  * ti_buf_put
1786  *
1787  * Copy data data from a user buffer and put it into the circular buffer.
1788  * Restrict to the amount of space available.
1789  *
1790  * Return the number of bytes copied.
1791  */
1792
1793 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1794 {
1795         int c, ret = 0;
1796
1797         while (1) {
1798                 c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1799                 if (count < c)
1800                         c = count;
1801                 if (c <= 0)
1802                         break;
1803                 memcpy(cb->buf + cb->head, buf, c);
1804                 cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1805                 buf += c;
1806                 count -= c;
1807                 ret += c;
1808         }
1809
1810         return ret;
1811 }
1812
1813
1814 /*
1815  * ti_buf_get
1816  *
1817  * Get data from the circular buffer and copy to the given buffer.
1818  * Restrict to the amount of data available.
1819  *
1820  * Return the number of bytes copied.
1821  */
1822
1823 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1824 {
1825         int c, ret = 0;
1826
1827         while (1) {
1828                 c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1829                 if (count < c)
1830                         c = count;
1831                 if (c <= 0)
1832                         break;
1833                 memcpy(buf, cb->buf + cb->tail, c);
1834                 cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1835                 buf += c;
1836                 count -= c;
1837                 ret += c;
1838         }
1839
1840         return ret;
1841 }