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/kernel.h>
  72 #include <linux/errno.h>
  73 #include <linux/init.h>
  74 #include <linux/slab.h>
  75 #include <linux/tty.h>
  76 #include <linux/tty_driver.h>
  77 #include <linux/tty_flip.h>
  78 #include <linux/module.h>
  79 #include <linux/spinlock.h>
  80 #include <linux/ioctl.h>
  81 #include <linux/serial.h>
  82 #include <linux/circ_buf.h>
  83 #include <linux/mutex.h>
  84 #include <asm/uaccess.h>
  85 #include <linux/usb.h>
  86 #include <linux/usb/serial.h>
  87
  88 #include "ti_usb_3410_5052.h"
  89 #include "ti_fw_3410.h"         /* firmware image for 3410 */
  90 #include "ti_fw_5052.h"         /* firmware image for 5052 */
  91
  92
  93 /* Defines */
  94
  95 #define TI_DRIVER_VERSION       "v0.9"
  96 #define TI_DRIVER_AUTHOR        "Al Borchers <alborchers@steinerpoint.com>"
  97 #define TI_DRIVER_DESC          "TI USB 3410/5052 Serial Driver"
  98
  99 #define TI_FIRMWARE_BUF_SIZE    16284
 100
 101 #define TI_WRITE_BUF_SIZE       1024
 102
 103 #define TI_TRANSFER_TIMEOUT     2
 104
 105 #define TI_DEFAULT_LOW_LATENCY  0
 106 #define TI_DEFAULT_CLOSING_WAIT 4000            /* in .01 secs */
 107
 108 /* supported setserial flags */
 109 #define TI_SET_SERIAL_FLAGS     (ASYNC_LOW_LATENCY)
 110
 111 /* read urb states */
 112 #define TI_READ_URB_RUNNING     0
 113 #define TI_READ_URB_STOPPING    1
 114 #define TI_READ_URB_STOPPED     2
 115
 116 #define TI_EXTRA_VID_PID_COUNT  5
 117
 118
 119 /* Structures */
 120
 121 struct ti_port {
 122         int                     tp_is_open;
 123         __u8                    tp_msr;
 124         __u8                    tp_lsr;
 125         __u8                    tp_shadow_mcr;
 126         __u8                    tp_uart_mode;   /* 232 or 485 modes */
 127         unsigned int            tp_uart_base_addr;
 128         int                     tp_flags;
 129         int                     tp_closing_wait;/* in .01 secs */
 130         struct async_icount     tp_icount;
 131         wait_queue_head_t       tp_msr_wait;    /* wait for msr change */
 132         wait_queue_head_t       tp_write_wait;
 133         struct ti_device        *tp_tdev;
 134         struct usb_serial_port  *tp_port;
 135         spinlock_t              tp_lock;
 136         int                     tp_read_urb_state;
 137         int                     tp_write_urb_in_use;
 138         struct circ_buf         *tp_write_buf;
 139 };
 140
 141 struct ti_device {
 142         struct mutex            td_open_close_lock;
 143         int                     td_open_port_count;
 144         struct usb_serial       *td_serial;
 145         int                     td_is_3410;
 146         int                     td_urb_error;
 147 };
 148
 149
 150 /* Function Declarations */
 151
 152 static int ti_startup(struct usb_serial *serial);
 153 static void ti_shutdown(struct usb_serial *serial);
 154 static int ti_open(struct usb_serial_port *port, struct file *file);
 155 static void ti_close(struct usb_serial_port *port, struct file *file);
 156 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
 157         int count);
 158 static int ti_write_room(struct usb_serial_port *port);
 159 static int ti_chars_in_buffer(struct usb_serial_port *port);
 160 static void ti_throttle(struct usb_serial_port *port);
 161 static void ti_unthrottle(struct usb_serial_port *port);
 162 static int ti_ioctl(struct usb_serial_port *port, struct file *file, unsigned int cmd, unsigned long arg);
 163 static void ti_set_termios(struct usb_serial_port *port,
 164         struct ktermios *old_termios);
 165 static int ti_tiocmget(struct usb_serial_port *port, struct file *file);
 166 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
 167         unsigned int set, unsigned int clear);
 168 static void ti_break(struct usb_serial_port *port, int break_state);
 169 static void ti_interrupt_callback(struct urb *urb);
 170 static void ti_bulk_in_callback(struct urb *urb);
 171 static void ti_bulk_out_callback(struct urb *urb);
 172
 173 static void ti_recv(struct device *dev, struct tty_struct *tty,
 174         unsigned char *data, int length);
 175 static void ti_send(struct ti_port *tport);
 176 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
 177 static int ti_get_lsr(struct ti_port *tport);
 178 static int ti_get_serial_info(struct ti_port *tport,
 179         struct serial_struct __user *ret_arg);
 180 static int ti_set_serial_info(struct ti_port *tport,
 181         struct serial_struct __user *new_arg);
 182 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
 183
 184 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
 185
 186 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
 187 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
 188
 189 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
 190         __u16 moduleid, __u16 value, __u8 *data, int size);
 191 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
 192         __u16 moduleid, __u16 value, __u8 *data, int size);
 193
 194 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
 195         __u8 mask, __u8 byte);
 196
 197 static int ti_download_firmware(struct ti_device *tdev,
 198         unsigned char *firmware, unsigned int firmware_size);
 199
 200 /* circular buffer */
 201 static struct circ_buf *ti_buf_alloc(void);
 202 static void ti_buf_free(struct circ_buf *cb);
 203 static void ti_buf_clear(struct circ_buf *cb);
 204 static int ti_buf_data_avail(struct circ_buf *cb);
 205 static int ti_buf_space_avail(struct circ_buf *cb);
 206 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count);
 207 static int ti_buf_get(struct circ_buf *cb, char *buf, int count);
 208
 209
 210 /* Data */
 211
 212 /* module parameters */
 213 static int debug;
 214 static int low_latency = TI_DEFAULT_LOW_LATENCY;
 215 static int closing_wait = TI_DEFAULT_CLOSING_WAIT;
 216 static ushort vendor_3410[TI_EXTRA_VID_PID_COUNT];
 217 static unsigned int vendor_3410_count;
 218 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
 219 static unsigned int product_3410_count;
 220 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
 221 static unsigned int vendor_5052_count;
 222 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
 223 static unsigned int product_5052_count;
 224
 225 /* supported devices */
 226 /* the array dimension is the number of default entries plus */
 227 /* TI_EXTRA_VID_PID_COUNT user defined entries plus 1 terminating */
 228 /* null entry */
 229 static struct usb_device_id ti_id_table_3410[1+TI_EXTRA_VID_PID_COUNT+1] = {
 230         { USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
 231         { USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_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_3410_EZ430_ID) },
 244         { USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
 245         { USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
 246         { USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
 247         { USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
 248         { }
 249 };
 250
 251 static struct usb_driver ti_usb_driver = {
 252         .name                   = "ti_usb_3410_5052",
 253         .probe                  = usb_serial_probe,
 254         .disconnect             = usb_serial_disconnect,
 255         .id_table               = ti_id_table_combined,
 256         .no_dynamic_id =        1,
 257 };
 258
 259 static struct usb_serial_driver ti_1port_device = {
 260         .driver = {
 261                 .owner          = THIS_MODULE,
 262                 .name           = "ti_usb_3410_5052_1",
 263         },
 264         .description            = "TI USB 3410 1 port adapter",
 265         .usb_driver             = &ti_usb_driver,
 266         .id_table               = ti_id_table_3410,
 267         .num_interrupt_in       = NUM_DONT_CARE,
 268         .num_bulk_in            = NUM_DONT_CARE,
 269         .num_bulk_out           = 1,
 270         .num_ports              = 1,
 271         .attach                 = ti_startup,
 272         .shutdown               = ti_shutdown,
 273         .open                   = ti_open,
 274         .close                  = ti_close,
 275         .write                  = ti_write,
 276         .write_room             = ti_write_room,
 277         .chars_in_buffer        = ti_chars_in_buffer,
 278         .throttle               = ti_throttle,
 279         .unthrottle             = ti_unthrottle,
 280         .ioctl                  = ti_ioctl,
 281         .set_termios            = ti_set_termios,
 282         .tiocmget               = ti_tiocmget,
 283         .tiocmset               = ti_tiocmset,
 284         .break_ctl              = ti_break,
 285         .read_int_callback      = ti_interrupt_callback,
 286         .read_bulk_callback     = ti_bulk_in_callback,
 287         .write_bulk_callback    = ti_bulk_out_callback,
 288 };
 289
 290 static struct usb_serial_driver ti_2port_device = {
 291         .driver = {
 292                 .owner          = THIS_MODULE,
 293                 .name           = "ti_usb_3410_5052_2",
 294         },
 295         .description            = "TI USB 5052 2 port adapter",
 296         .usb_driver             = &ti_usb_driver,
 297         .id_table               = ti_id_table_5052,
 298         .num_interrupt_in       = 1,
 299         .num_bulk_in            = 2,
 300         .num_bulk_out           = 2,
 301         .num_ports              = 2,
 302         .attach                 = ti_startup,
 303         .shutdown               = ti_shutdown,
 304         .open                   = ti_open,
 305         .close                  = ti_close,
 306         .write                  = ti_write,
 307         .write_room             = ti_write_room,
 308         .chars_in_buffer        = ti_chars_in_buffer,
 309         .throttle               = ti_throttle,
 310         .unthrottle             = ti_unthrottle,
 311         .ioctl                  = ti_ioctl,
 312         .set_termios            = ti_set_termios,
 313         .tiocmget               = ti_tiocmget,
 314         .tiocmset               = ti_tiocmset,
 315         .break_ctl              = ti_break,
 316         .read_int_callback      = ti_interrupt_callback,
 317         .read_bulk_callback     = ti_bulk_in_callback,
 318         .write_bulk_callback    = ti_bulk_out_callback,
 319 };
 320
 321
 322 /* Module */
 323
 324 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
 325 MODULE_DESCRIPTION(TI_DRIVER_DESC);
 326 MODULE_VERSION(TI_DRIVER_VERSION);
 327 MODULE_LICENSE("GPL");
 328
 329 module_param(debug, bool, S_IRUGO | S_IWUSR);
 330 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
 331
 332 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
 333 MODULE_PARM_DESC(low_latency, "TTY low_latency flag, 0=off, 1=on, default is off");
 334
 335 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
 336 MODULE_PARM_DESC(closing_wait, "Maximum wait for data to drain in close, in .01 secs, default is 4000");
 337
 338 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
 339 MODULE_PARM_DESC(vendor_3410, "Vendor ids for 3410 based devices, 1-5 short integers");
 340 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
 341 MODULE_PARM_DESC(product_3410, "Product ids for 3410 based devices, 1-5 short integers");
 342 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
 343 MODULE_PARM_DESC(vendor_5052, "Vendor ids for 5052 based devices, 1-5 short integers");
 344 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
 345 MODULE_PARM_DESC(product_5052, "Product ids for 5052 based devices, 1-5 short integers");
 346
 347 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
 348
 349
 350 /* Functions */
 351
 352 static int __init ti_init(void)
 353 {
 354         int i,j;
 355         int ret;
 356
 357         /* insert extra vendor and product ids */
 358         j = ARRAY_SIZE(ti_id_table_3410) - TI_EXTRA_VID_PID_COUNT - 1;
 359         for (i=0; i<min(vendor_3410_count,product_3410_count); i++,j++) {
 360                 ti_id_table_3410[j].idVendor = vendor_3410[i];
 361                 ti_id_table_3410[j].idProduct = product_3410[i];
 362                 ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 363         }
 364         j = ARRAY_SIZE(ti_id_table_5052) - TI_EXTRA_VID_PID_COUNT - 1;
 365         for (i=0; i<min(vendor_5052_count,product_5052_count); i++,j++) {
 366                 ti_id_table_5052[j].idVendor = vendor_5052[i];
 367                 ti_id_table_5052[j].idProduct = product_5052[i];
 368                 ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 369         }
 370
 371         ret = usb_serial_register(&ti_1port_device);
 372         if (ret)
 373                 goto failed_1port;
 374         ret = usb_serial_register(&ti_2port_device);
 375         if (ret)
 376                 goto failed_2port;
 377
 378         ret = usb_register(&ti_usb_driver);
 379         if (ret)
 380                 goto failed_usb;
 381
 382         info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
 383
 384         return 0;
 385
 386 failed_usb:
 387         usb_serial_deregister(&ti_2port_device);
 388 failed_2port:
 389         usb_serial_deregister(&ti_1port_device);
 390 failed_1port:
 391         return ret;
 392 }
 393
 394
 395 static void __exit ti_exit(void)
 396 {
 397         usb_serial_deregister(&ti_1port_device);
 398         usb_serial_deregister(&ti_2port_device);
 399         usb_deregister(&ti_usb_driver);
 400 }
 401
 402
 403 module_init(ti_init);
 404 module_exit(ti_exit);
 405
 406
 407 static int ti_startup(struct usb_serial *serial)
 408 {
 409         struct ti_device *tdev;
 410         struct ti_port *tport;
 411         struct usb_device *dev = serial->dev;
 412         int status;
 413         int i;
 414
 415
 416         dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
 417             __FUNCTION__, le16_to_cpu(dev->descriptor.idProduct),
 418             dev->descriptor.bNumConfigurations,
 419             dev->actconfig->desc.bConfigurationValue);
 420
 421         /* create device structure */
 422         tdev = kzalloc(sizeof(struct ti_device), GFP_KERNEL);
 423         if (tdev == NULL) {
 424                 dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
 425                 return -ENOMEM;
 426         }
 427         mutex_init(&tdev->td_open_close_lock);
 428         tdev->td_serial = serial;
 429         usb_set_serial_data(serial, tdev);
 430
 431         /* determine device type */
 432         if (usb_match_id(serial->interface, ti_id_table_3410))
 433                 tdev->td_is_3410 = 1;
 434         dbg("%s - device type is %s", __FUNCTION__, tdev->td_is_3410 ? "3410" : "5052");
 435
 436         /* if we have only 1 configuration, download firmware */
 437         if (dev->descriptor.bNumConfigurations == 1) {
 438
 439                 if (tdev->td_is_3410)
 440                         status = ti_download_firmware(tdev, ti_fw_3410,
 441                                 sizeof(ti_fw_3410));
 442                 else
 443                         status = ti_download_firmware(tdev, ti_fw_5052,
 444                                 sizeof(ti_fw_5052));
 445                 if (status)
 446                         goto free_tdev;
 447
 448                 /* 3410 must be reset, 5052 resets itself */
 449                 if (tdev->td_is_3410) {
 450                         msleep_interruptible(100);
 451                         usb_reset_device(dev);
 452                 }
 453
 454                 status = -ENODEV;
 455                 goto free_tdev;
 456         }
 457
 458         /* the second configuration must be set (in sysfs by hotplug script) */
 459         if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
 460                 status = -ENODEV;
 461                 goto free_tdev;
 462         }
 463
 464         /* set up port structures */
 465         for (i = 0; i < serial->num_ports; ++i) {
 466                 tport = kzalloc(sizeof(struct ti_port), GFP_KERNEL);
 467                 if (tport == NULL) {
 468                         dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
 469                         status = -ENOMEM;
 470                         goto free_tports;
 471                 }
 472                 spin_lock_init(&tport->tp_lock);
 473                 tport->tp_uart_base_addr = (i == 0 ? TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
 474                 tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
 475                 tport->tp_closing_wait = closing_wait;
 476                 init_waitqueue_head(&tport->tp_msr_wait);
 477                 init_waitqueue_head(&tport->tp_write_wait);
 478                 tport->tp_write_buf = ti_buf_alloc();
 479                 if (tport->tp_write_buf == NULL) {
 480                         dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
 481                         kfree(tport);
 482                         status = -ENOMEM;
 483                         goto free_tports;
 484                 }
 485                 tport->tp_port = serial->port[i];
 486                 tport->tp_tdev = tdev;
 487                 usb_set_serial_port_data(serial->port[i], tport);
 488                 tport->tp_uart_mode = 0;        /* default is RS232 */
 489         }
 490
 491         return 0;
 492
 493 free_tports:
 494         for (--i; i>=0; --i) {
 495                 tport = usb_get_serial_port_data(serial->port[i]);
 496                 ti_buf_free(tport->tp_write_buf);
 497                 kfree(tport);
 498                 usb_set_serial_port_data(serial->port[i], NULL);
 499         }
 500 free_tdev:
 501         kfree(tdev);
 502         usb_set_serial_data(serial, NULL);
 503         return status;
 504 }
 505
 506
 507 static void ti_shutdown(struct usb_serial *serial)
 508 {
 509         int i;
 510         struct ti_device *tdev = usb_get_serial_data(serial);
 511         struct ti_port *tport;
 512
 513         dbg("%s", __FUNCTION__);
 514
 515         for (i=0; i < serial->num_ports; ++i) {
 516                 tport = usb_get_serial_port_data(serial->port[i]);
 517                 if (tport) {
 518                         ti_buf_free(tport->tp_write_buf);
 519                         kfree(tport);
 520                         usb_set_serial_port_data(serial->port[i], NULL);
 521                 }
 522         }
 523
 524         kfree(tdev);
 525         usb_set_serial_data(serial, NULL);
 526 }
 527
 528
 529 static int ti_open(struct usb_serial_port *port, struct file *file)
 530 {
 531         struct ti_port *tport = usb_get_serial_port_data(port);
 532         struct ti_device *tdev;
 533         struct usb_device *dev;
 534         struct urb *urb;
 535         int port_number;
 536         int status;
 537         __u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
 538                              TI_PIPE_TIMEOUT_ENABLE |
 539                              (TI_TRANSFER_TIMEOUT << 2));
 540
 541         dbg("%s - port %d", __FUNCTION__, port->number);
 542
 543         if (tport == NULL)
 544                 return -ENODEV;
 545
 546         dev = port->serial->dev;
 547         tdev = tport->tp_tdev;
 548
 549         /* only one open on any port on a device at a time */
 550         if (mutex_lock_interruptible(&tdev->td_open_close_lock))
 551                 return -ERESTARTSYS;
 552
 553         if (port->tty)
 554                 port->tty->low_latency =
 555                         (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 556
 557         port_number = port->number - port->serial->minor;
 558
 559         memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
 560
 561         tport->tp_msr = 0;
 562         tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
 563
 564         /* start interrupt urb the first time a port is opened on this device */
 565         if (tdev->td_open_port_count == 0) {
 566                 dbg("%s - start interrupt in urb", __FUNCTION__);
 567                 urb = tdev->td_serial->port[0]->interrupt_in_urb;
 568                 if (!urb) {
 569                         dev_err(&port->dev, "%s - no interrupt urb\n", __FUNCTION__);
 570                         status = -EINVAL;
 571                         goto release_lock;
 572                 }
 573                 urb->complete = ti_interrupt_callback;
 574                 urb->context = tdev;
 575                 urb->dev = dev;
 576                 status = usb_submit_urb(urb, GFP_KERNEL);
 577                 if (status) {
 578                         dev_err(&port->dev, "%s - submit interrupt urb failed, %d\n", __FUNCTION__, status);
 579                         goto release_lock;
 580                 }
 581         }
 582
 583         ti_set_termios(port, port->tty->termios);
 584
 585         dbg("%s - sending TI_OPEN_PORT", __FUNCTION__);
 586         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 587                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 588         if (status) {
 589                 dev_err(&port->dev, "%s - cannot send open command, %d\n", __FUNCTION__, status);
 590                 goto unlink_int_urb;
 591         }
 592
 593         dbg("%s - sending TI_START_PORT", __FUNCTION__);
 594         status = ti_command_out_sync(tdev, TI_START_PORT,
 595                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 596         if (status) {
 597                 dev_err(&port->dev, "%s - cannot send start command, %d\n", __FUNCTION__, status);
 598                 goto unlink_int_urb;
 599         }
 600
 601         dbg("%s - sending TI_PURGE_PORT", __FUNCTION__);
 602         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 603                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
 604         if (status) {
 605                 dev_err(&port->dev, "%s - cannot clear input buffers, %d\n", __FUNCTION__, status);
 606                 goto unlink_int_urb;
 607         }
 608         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 609                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
 610         if (status) {
 611                 dev_err(&port->dev, "%s - cannot clear output buffers, %d\n", __FUNCTION__, status);
 612                 goto unlink_int_urb;
 613         }
 614
 615         /* reset the data toggle on the bulk endpoints to work around bug in
 616          * host controllers where things get out of sync some times */
 617         usb_clear_halt(dev, port->write_urb->pipe);
 618         usb_clear_halt(dev, port->read_urb->pipe);
 619
 620         ti_set_termios(port, port->tty->termios);
 621
 622         dbg("%s - sending TI_OPEN_PORT (2)", __FUNCTION__);
 623         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 624                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 625         if (status) {
 626                 dev_err(&port->dev, "%s - cannot send open command (2), %d\n", __FUNCTION__, status);
 627                 goto unlink_int_urb;
 628         }
 629
 630         dbg("%s - sending TI_START_PORT (2)", __FUNCTION__);
 631         status = ti_command_out_sync(tdev, TI_START_PORT,
 632                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 633         if (status) {
 634                 dev_err(&port->dev, "%s - cannot send start command (2), %d\n", __FUNCTION__, status);
 635                 goto unlink_int_urb;
 636         }
 637
 638         /* start read urb */
 639         dbg("%s - start read urb", __FUNCTION__);
 640         urb = port->read_urb;
 641         if (!urb) {
 642                 dev_err(&port->dev, "%s - no read urb\n", __FUNCTION__);
 643                 status = -EINVAL;
 644                 goto unlink_int_urb;
 645         }
 646         tport->tp_read_urb_state = TI_READ_URB_RUNNING;
 647         urb->complete = ti_bulk_in_callback;
 648         urb->context = tport;
 649         urb->dev = dev;
 650         status = usb_submit_urb(urb, GFP_KERNEL);
 651         if (status) {
 652                 dev_err(&port->dev, "%s - submit read urb failed, %d\n", __FUNCTION__, status);
 653                 goto unlink_int_urb;
 654         }
 655
 656         tport->tp_is_open = 1;
 657         ++tdev->td_open_port_count;
 658
 659         goto release_lock;
 660
 661 unlink_int_urb:
 662         if (tdev->td_open_port_count == 0)
 663                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 664 release_lock:
 665         mutex_unlock(&tdev->td_open_close_lock);
 666         dbg("%s - exit %d", __FUNCTION__, status);
 667         return status;
 668 }
 669
 670
 671 static void ti_close(struct usb_serial_port *port, struct file *file)
 672 {
 673         struct ti_device *tdev;
 674         struct ti_port *tport;
 675         int port_number;
 676         int status;
 677         int do_unlock;
 678
 679         dbg("%s - port %d", __FUNCTION__, port->number);
 680
 681         tdev = usb_get_serial_data(port->serial);
 682         tport = usb_get_serial_port_data(port);
 683         if (tdev == NULL || tport == NULL)
 684                 return;
 685
 686         tport->tp_is_open = 0;
 687
 688         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
 689
 690         usb_kill_urb(port->read_urb);
 691         usb_kill_urb(port->write_urb);
 692         tport->tp_write_urb_in_use = 0;
 693
 694         port_number = port->number - port->serial->minor;
 695
 696         dbg("%s - sending TI_CLOSE_PORT", __FUNCTION__);
 697         status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
 698                      (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 699         if (status)
 700                 dev_err(&port->dev, "%s - cannot send close port command, %d\n" , __FUNCTION__, status);
 701
 702         /* if mutex_lock is interrupted, continue anyway */
 703         do_unlock = !mutex_lock_interruptible(&tdev->td_open_close_lock);
 704         --tport->tp_tdev->td_open_port_count;
 705         if (tport->tp_tdev->td_open_port_count <= 0) {
 706                 /* last port is closed, shut down interrupt urb */
 707                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 708                 tport->tp_tdev->td_open_port_count = 0;
 709         }
 710         if (do_unlock)
 711                 mutex_unlock(&tdev->td_open_close_lock);
 712
 713         dbg("%s - exit", __FUNCTION__);
 714 }
 715
 716
 717 static int ti_write(struct usb_serial_port *port, const unsigned char *data,
 718         int count)
 719 {
 720         struct ti_port *tport = usb_get_serial_port_data(port);
 721         unsigned long flags;
 722
 723         dbg("%s - port %d", __FUNCTION__, port->number);
 724
 725         if (count == 0) {
 726                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 727                 return 0;
 728         }
 729
 730         if (tport == NULL || !tport->tp_is_open)
 731                 return -ENODEV;
 732
 733         spin_lock_irqsave(&tport->tp_lock, flags);
 734         count = ti_buf_put(tport->tp_write_buf, data, count);
 735         spin_unlock_irqrestore(&tport->tp_lock, flags);
 736
 737         ti_send(tport);
 738
 739         return count;
 740 }
 741
 742
 743 static int ti_write_room(struct usb_serial_port *port)
 744 {
 745         struct ti_port *tport = usb_get_serial_port_data(port);
 746         int room = 0;
 747         unsigned long flags;
 748
 749         dbg("%s - port %d", __FUNCTION__, port->number);
 750
 751         if (tport == NULL)
 752                 return -ENODEV;
 753
 754         spin_lock_irqsave(&tport->tp_lock, flags);
 755         room = ti_buf_space_avail(tport->tp_write_buf);
 756         spin_unlock_irqrestore(&tport->tp_lock, flags);
 757
 758         dbg("%s - returns %d", __FUNCTION__, room);
 759         return room;
 760 }
 761
 762
 763 static int ti_chars_in_buffer(struct usb_serial_port *port)
 764 {
 765         struct ti_port *tport = usb_get_serial_port_data(port);
 766         int chars = 0;
 767         unsigned long flags;
 768
 769         dbg("%s - port %d", __FUNCTION__, port->number);
 770
 771         if (tport == NULL)
 772                 return -ENODEV;
 773
 774         spin_lock_irqsave(&tport->tp_lock, flags);
 775         chars = ti_buf_data_avail(tport->tp_write_buf);
 776         spin_unlock_irqrestore(&tport->tp_lock, flags);
 777
 778         dbg("%s - returns %d", __FUNCTION__, chars);
 779         return chars;
 780 }
 781
 782
 783 static void ti_throttle(struct usb_serial_port *port)
 784 {
 785         struct ti_port *tport = usb_get_serial_port_data(port);
 786         struct tty_struct *tty;
 787
 788         dbg("%s - port %d", __FUNCTION__, port->number);
 789
 790         if (tport == NULL)
 791                 return;
 792
 793         tty = port->tty;
 794         if (!tty) {
 795                 dbg("%s - no tty", __FUNCTION__);
 796                 return;
 797         }
 798
 799         if (I_IXOFF(tty) || C_CRTSCTS(tty))
 800                 ti_stop_read(tport, tty);
 801
 802 }
 803
 804
 805 static void ti_unthrottle(struct usb_serial_port *port)
 806 {
 807         struct ti_port *tport = usb_get_serial_port_data(port);
 808         struct tty_struct *tty;
 809         int status;
 810
 811         dbg("%s - port %d", __FUNCTION__, port->number);
 812
 813         if (tport == NULL)
 814                 return;
 815
 816         tty = port->tty;
 817         if (!tty) {
 818                 dbg("%s - no tty", __FUNCTION__);
 819                 return;
 820         }
 821
 822         if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
 823                 status = ti_restart_read(tport, tty);
 824                 if (status)
 825                         dev_err(&port->dev, "%s - cannot restart read, %d\n", __FUNCTION__, status);
 826         }
 827 }
 828
 829
 830 static int ti_ioctl(struct usb_serial_port *port, struct file *file,
 831         unsigned int cmd, unsigned long arg)
 832 {
 833         struct ti_port *tport = usb_get_serial_port_data(port);
 834         struct async_icount cnow;
 835         struct async_icount cprev;
 836
 837         dbg("%s - port %d, cmd = 0x%04X", __FUNCTION__, port->number, cmd);
 838
 839         if (tport == NULL)
 840                 return -ENODEV;
 841
 842         switch (cmd) {
 843                 case TIOCGSERIAL:
 844                         dbg("%s - (%d) TIOCGSERIAL", __FUNCTION__, port->number);
 845                         return ti_get_serial_info(tport, (struct serial_struct __user *)arg);
 846                         break;
 847
 848                 case TIOCSSERIAL:
 849                         dbg("%s - (%d) TIOCSSERIAL", __FUNCTION__, port->number);
 850                         return ti_set_serial_info(tport, (struct serial_struct __user *)arg);
 851                         break;
 852
 853                 case TIOCMIWAIT:
 854                         dbg("%s - (%d) TIOCMIWAIT", __FUNCTION__, port->number);
 855                         cprev = tport->tp_icount;
 856                         while (1) {
 857                                 interruptible_sleep_on(&tport->tp_msr_wait);
 858                                 if (signal_pending(current))
 859                                         return -ERESTARTSYS;
 860                                 cnow = tport->tp_icount;
 861                                 if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
 862                                     cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
 863                                         return -EIO; /* no change => error */
 864                                 if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 865                                     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 866                                     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
 867                                     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
 868                                         return 0;
 869                                 }
 870                                 cprev = cnow;
 871                         }
 872                         break;
 873
 874                 case TIOCGICOUNT:
 875                         dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d", __FUNCTION__, port->number, tport->tp_icount.rx, tport->tp_icount.tx);
 876                         if (copy_to_user((void __user *)arg, &tport->tp_icount, sizeof(tport->tp_icount)))
 877                                 return -EFAULT;
 878                         return 0;
 879         }
 880
 881         return -ENOIOCTLCMD;
 882 }
 883
 884
 885 static void ti_set_termios(struct usb_serial_port *port,
 886         struct ktermios *old_termios)
 887 {
 888         struct ti_port *tport = usb_get_serial_port_data(port);
 889         struct tty_struct *tty = port->tty;
 890         struct ti_uart_config *config;
 891         tcflag_t cflag,iflag;
 892         int baud;
 893         int status;
 894         int port_number = port->number - port->serial->minor;
 895         unsigned int mcr;
 896
 897         dbg("%s - port %d", __FUNCTION__, port->number);
 898
 899         cflag = tty->termios->c_cflag;
 900         iflag = tty->termios->c_iflag;
 901
 902         dbg("%s - cflag %08x, iflag %08x", __FUNCTION__, cflag, iflag);
 903         dbg("%s - old clfag %08x, old iflag %08x", __FUNCTION__, old_termios->c_cflag, old_termios->c_iflag);
 904
 905         if (tport == NULL)
 906                 return;
 907
 908         config = kmalloc(sizeof(*config), GFP_KERNEL);
 909         if (!config) {
 910                 dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
 911                 return;
 912         }
 913
 914         config->wFlags = 0;
 915
 916         /* these flags must be set */
 917         config->wFlags |= TI_UART_ENABLE_MS_INTS;
 918         config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
 919         config->bUartMode = (__u8)(tport->tp_uart_mode);
 920
 921         switch (cflag & CSIZE) {
 922                 case CS5:
 923                             config->bDataBits = TI_UART_5_DATA_BITS;
 924                             break;
 925                 case CS6:
 926                             config->bDataBits = TI_UART_6_DATA_BITS;
 927                             break;
 928                 case CS7:
 929                             config->bDataBits = TI_UART_7_DATA_BITS;
 930                             break;
 931                 default:
 932                 case CS8:
 933                             config->bDataBits = TI_UART_8_DATA_BITS;
 934                             break;
 935         }
 936
 937         /* CMSPAR isn't supported by this driver */
 938         tty->termios->c_cflag &= ~CMSPAR;
 939
 940         if (cflag & PARENB) {
 941                 if (cflag & PARODD) {
 942                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 943                         config->bParity = TI_UART_ODD_PARITY;
 944                 } else {
 945                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 946                         config->bParity = TI_UART_EVEN_PARITY;
 947                 }
 948         } else {
 949                 config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
 950                 config->bParity = TI_UART_NO_PARITY;
 951         }
 952
 953         if (cflag & CSTOPB)
 954                 config->bStopBits = TI_UART_2_STOP_BITS;
 955         else
 956                 config->bStopBits = TI_UART_1_STOP_BITS;
 957
 958         if (cflag & CRTSCTS) {
 959                 /* RTS flow control must be off to drop RTS for baud rate B0 */
 960                 if ((cflag & CBAUD) != B0)
 961                         config->wFlags |= TI_UART_ENABLE_RTS_IN;
 962                 config->wFlags |= TI_UART_ENABLE_CTS_OUT;
 963         } else {
 964                 tty->hw_stopped = 0;
 965                 ti_restart_read(tport, tty);
 966         }
 967
 968         if (I_IXOFF(tty) || I_IXON(tty)) {
 969                 config->cXon  = START_CHAR(tty);
 970                 config->cXoff = STOP_CHAR(tty);
 971
 972                 if (I_IXOFF(tty))
 973                         config->wFlags |= TI_UART_ENABLE_X_IN;
 974                 else
 975                         ti_restart_read(tport, tty);
 976
 977                 if (I_IXON(tty))
 978                         config->wFlags |= TI_UART_ENABLE_X_OUT;
 979         }
 980
 981         baud = tty_get_baud_rate(tty);
 982         if (!baud)
 983                 baud = 9600;
 984         if (tport->tp_tdev->td_is_3410)
 985                 config->wBaudRate = (__u16)((923077 + baud/2) / baud);
 986         else
 987                 config->wBaudRate = (__u16)((461538 + baud/2) / baud);
 988
 989         /* FIXME: Should calculate resulting baud here and report it back */
 990         if ((cflag & CBAUD) != B0)
 991                 tty_encode_baud_rate(tty, baud, baud);
 992
 993         dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
 994         __FUNCTION__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
 995
 996         cpu_to_be16s(&config->wBaudRate);
 997         cpu_to_be16s(&config->wFlags);
 998
 999         status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1000                 (__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1001                 sizeof(*config));
1002         if (status)
1003                 dev_err(&port->dev, "%s - cannot set config on port %d, %d\n", __FUNCTION__, port_number, status);
1004
1005         /* SET_CONFIG asserts RTS and DTR, reset them correctly */
1006         mcr = tport->tp_shadow_mcr;
1007         /* if baud rate is B0, clear RTS and DTR */
1008         if ((cflag & CBAUD) == B0)
1009                 mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1010         status = ti_set_mcr(tport, mcr);
1011         if (status)
1012                 dev_err(&port->dev, "%s - cannot set modem control on port %d, %d\n", __FUNCTION__, port_number, status);
1013
1014         kfree(config);
1015 }
1016
1017
1018 static int ti_tiocmget(struct usb_serial_port *port, struct file *file)
1019 {
1020         struct ti_port *tport = usb_get_serial_port_data(port);
1021         unsigned int result;
1022         unsigned int msr;
1023         unsigned int mcr;
1024         unsigned long flags;
1025
1026         dbg("%s - port %d", __FUNCTION__, port->number);
1027
1028         if (tport == NULL)
1029                 return -ENODEV;
1030
1031         spin_lock_irqsave(&tport->tp_lock, flags);
1032         msr = tport->tp_msr;
1033         mcr = tport->tp_shadow_mcr;
1034         spin_unlock_irqrestore(&tport->tp_lock, flags);
1035
1036         result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1037                 | ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1038                 | ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1039                 | ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1040                 | ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1041                 | ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1042                 | ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1043
1044         dbg("%s - 0x%04X", __FUNCTION__, result);
1045
1046         return result;
1047 }
1048
1049
1050 static int ti_tiocmset(struct usb_serial_port *port, struct file *file,
1051         unsigned int set, unsigned int clear)
1052 {
1053         struct ti_port *tport = usb_get_serial_port_data(port);
1054         unsigned int mcr;
1055         unsigned long flags;
1056
1057         dbg("%s - port %d", __FUNCTION__, port->number);
1058
1059         if (tport == NULL)
1060                 return -ENODEV;
1061
1062         spin_lock_irqsave(&tport->tp_lock, flags);
1063         mcr = tport->tp_shadow_mcr;
1064
1065         if (set & TIOCM_RTS)
1066                 mcr |= TI_MCR_RTS;
1067         if (set & TIOCM_DTR)
1068                 mcr |= TI_MCR_DTR;
1069         if (set & TIOCM_LOOP)
1070                 mcr |= TI_MCR_LOOP;
1071
1072         if (clear & TIOCM_RTS)
1073                 mcr &= ~TI_MCR_RTS;
1074         if (clear & TIOCM_DTR)
1075                 mcr &= ~TI_MCR_DTR;
1076         if (clear & TIOCM_LOOP)
1077                 mcr &= ~TI_MCR_LOOP;
1078         spin_unlock_irqrestore(&tport->tp_lock, flags);
1079
1080         return ti_set_mcr(tport, mcr);
1081 }
1082
1083
1084 static void ti_break(struct usb_serial_port *port, int break_state)
1085 {
1086         struct ti_port *tport = usb_get_serial_port_data(port);
1087         int status;
1088
1089         dbg("%s - state = %d", __FUNCTION__, break_state);
1090
1091         if (tport == NULL)
1092                 return;
1093
1094         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1095
1096         status = ti_write_byte(tport->tp_tdev,
1097                 tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1098                 TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1099
1100         if (status)
1101                 dbg("%s - error setting break, %d", __FUNCTION__, status);
1102 }
1103
1104
1105 static void ti_interrupt_callback(struct urb *urb)
1106 {
1107         struct ti_device *tdev = (struct ti_device *)urb->context;
1108         struct usb_serial_port *port;
1109         struct usb_serial *serial = tdev->td_serial;
1110         struct ti_port *tport;
1111         struct device *dev = &urb->dev->dev;
1112         unsigned char *data = urb->transfer_buffer;
1113         int length = urb->actual_length;
1114         int port_number;
1115         int function;
1116         int status = urb->status;
1117         int retval;
1118         __u8 msr;
1119
1120         dbg("%s", __FUNCTION__);
1121
1122         switch (status) {
1123         case 0:
1124                 break;
1125         case -ECONNRESET:
1126         case -ENOENT:
1127         case -ESHUTDOWN:
1128                 dbg("%s - urb shutting down, %d", __FUNCTION__, status);
1129                 tdev->td_urb_error = 1;
1130                 return;
1131         default:
1132                 dev_err(dev, "%s - nonzero urb status, %d\n",
1133                         __FUNCTION__, status);
1134                 tdev->td_urb_error = 1;
1135                 goto exit;
1136         }
1137
1138         if (length != 2) {
1139                 dbg("%s - bad packet size, %d", __FUNCTION__, length);
1140                 goto exit;
1141         }
1142
1143         if (data[0] == TI_CODE_HARDWARE_ERROR) {
1144                 dev_err(dev, "%s - hardware error, %d\n", __FUNCTION__, data[1]);
1145                 goto exit;
1146         }
1147
1148         port_number = TI_GET_PORT_FROM_CODE(data[0]);
1149         function = TI_GET_FUNC_FROM_CODE(data[0]);
1150
1151         dbg("%s - port_number %d, function %d, data 0x%02X", __FUNCTION__, port_number, function, data[1]);
1152
1153         if (port_number >= serial->num_ports) {
1154                 dev_err(dev, "%s - bad port number, %d\n", __FUNCTION__, port_number);
1155                 goto exit;
1156         }
1157
1158         port = serial->port[port_number];
1159
1160         tport = usb_get_serial_port_data(port);
1161         if (!tport)
1162                 goto exit;
1163
1164         switch (function) {
1165         case TI_CODE_DATA_ERROR:
1166                 dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n", __FUNCTION__, port_number, data[1]);
1167                 break;
1168
1169         case TI_CODE_MODEM_STATUS:
1170                 msr = data[1];
1171                 dbg("%s - port %d, msr 0x%02X", __FUNCTION__, port_number, msr);
1172                 ti_handle_new_msr(tport, msr);
1173                 break;
1174
1175         default:
1176                 dev_err(dev, "%s - unknown interrupt code, 0x%02X\n", __FUNCTION__, data[1]);
1177                 break;
1178         }
1179
1180 exit:
1181         retval = usb_submit_urb(urb, GFP_ATOMIC);
1182         if (retval)
1183                 dev_err(dev, "%s - resubmit interrupt urb failed, %d\n",
1184                         __FUNCTION__, retval);
1185 }
1186
1187
1188 static void ti_bulk_in_callback(struct urb *urb)
1189 {
1190         struct ti_port *tport = (struct ti_port *)urb->context;
1191         struct usb_serial_port *port = tport->tp_port;
1192         struct device *dev = &urb->dev->dev;
1193         int status = urb->status;
1194         int retval = 0;
1195
1196         dbg("%s", __FUNCTION__);
1197
1198         switch (status) {
1199         case 0:
1200                 break;
1201         case -ECONNRESET:
1202         case -ENOENT:
1203         case -ESHUTDOWN:
1204                 dbg("%s - urb shutting down, %d", __FUNCTION__, status);
1205                 tport->tp_tdev->td_urb_error = 1;
1206                 wake_up_interruptible(&tport->tp_write_wait);
1207                 return;
1208         default:
1209                 dev_err(dev, "%s - nonzero urb status, %d\n",
1210                         __FUNCTION__, status );
1211                 tport->tp_tdev->td_urb_error = 1;
1212                 wake_up_interruptible(&tport->tp_write_wait);
1213         }
1214
1215         if (status == -EPIPE)
1216                 goto exit;
1217
1218         if (status) {
1219                 dev_err(dev, "%s - stopping read!\n", __FUNCTION__);
1220                 return;
1221         }
1222
1223         if (port->tty && urb->actual_length) {
1224                 usb_serial_debug_data(debug, dev, __FUNCTION__,
1225                         urb->actual_length, urb->transfer_buffer);
1226
1227                 if (!tport->tp_is_open)
1228                         dbg("%s - port closed, dropping data", __FUNCTION__);
1229                 else
1230                         ti_recv(&urb->dev->dev, port->tty, urb->transfer_buffer,
1231                                 urb->actual_length);
1232
1233                 spin_lock(&tport->tp_lock);
1234                 tport->tp_icount.rx += urb->actual_length;
1235                 spin_unlock(&tport->tp_lock);
1236         }
1237
1238 exit:
1239         /* continue to read unless stopping */
1240         spin_lock(&tport->tp_lock);
1241         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1242                 urb->dev = port->serial->dev;
1243                 retval = usb_submit_urb(urb, GFP_ATOMIC);
1244         } else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1245                 tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1246         }
1247         spin_unlock(&tport->tp_lock);
1248         if (retval)
1249                 dev_err(dev, "%s - resubmit read urb failed, %d\n",
1250                         __FUNCTION__, retval);
1251 }
1252
1253
1254 static void ti_bulk_out_callback(struct urb *urb)
1255 {
1256         struct ti_port *tport = (struct ti_port *)urb->context;
1257         struct usb_serial_port *port = tport->tp_port;
1258         struct device *dev = &urb->dev->dev;
1259         int status = urb->status;
1260
1261         dbg("%s - port %d", __FUNCTION__, port->number);
1262
1263         tport->tp_write_urb_in_use = 0;
1264
1265         switch (status) {
1266         case 0:
1267                 break;
1268         case -ECONNRESET:
1269         case -ENOENT:
1270         case -ESHUTDOWN:
1271                 dbg("%s - urb shutting down, %d", __FUNCTION__, status);
1272                 tport->tp_tdev->td_urb_error = 1;
1273                 wake_up_interruptible(&tport->tp_write_wait);
1274                 return;
1275         default:
1276                 dev_err(dev, "%s - nonzero urb status, %d\n",
1277                         __FUNCTION__, status);
1278                 tport->tp_tdev->td_urb_error = 1;
1279                 wake_up_interruptible(&tport->tp_write_wait);
1280         }
1281
1282         /* send any buffered data */
1283         ti_send(tport);
1284 }
1285
1286
1287 static void ti_recv(struct device *dev, struct tty_struct *tty,
1288         unsigned char *data, int length)
1289 {
1290         int cnt;
1291
1292         do {
1293                 cnt = tty_buffer_request_room(tty, length);
1294                 if (cnt < length) {
1295                         dev_err(dev, "%s - dropping data, %d bytes lost\n", __FUNCTION__, length - cnt);
1296                         if(cnt == 0)
1297                                 break;
1298                 }
1299                 tty_insert_flip_string(tty, data, cnt);
1300                 tty_flip_buffer_push(tty);
1301                 data += cnt;
1302                 length -= cnt;
1303         } while (length > 0);
1304
1305 }
1306
1307
1308 static void ti_send(struct ti_port *tport)
1309 {
1310         int count, result;
1311         struct usb_serial_port *port = tport->tp_port;
1312         struct tty_struct *tty = port->tty;
1313         unsigned long flags;
1314
1315
1316         dbg("%s - port %d", __FUNCTION__, port->number);
1317
1318         spin_lock_irqsave(&tport->tp_lock, flags);
1319
1320         if (tport->tp_write_urb_in_use) {
1321                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1322                 return;
1323         }
1324
1325         count = ti_buf_get(tport->tp_write_buf,
1326                                 port->write_urb->transfer_buffer,
1327                                 port->bulk_out_size);
1328
1329         if (count == 0) {
1330                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1331                 return;
1332         }
1333
1334         tport->tp_write_urb_in_use = 1;
1335
1336         spin_unlock_irqrestore(&tport->tp_lock, flags);
1337
1338         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);
1339
1340         usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1341                            usb_sndbulkpipe(port->serial->dev,
1342                                             port->bulk_out_endpointAddress),
1343                            port->write_urb->transfer_buffer, count,
1344                            ti_bulk_out_callback, tport);
1345
1346         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1347         if (result) {
1348                 dev_err(&port->dev, "%s - submit write urb failed, %d\n", __FUNCTION__, result);
1349                 tport->tp_write_urb_in_use = 0;
1350                 /* TODO: reschedule ti_send */
1351         } else {
1352                 spin_lock_irqsave(&tport->tp_lock, flags);
1353                 tport->tp_icount.tx += count;
1354                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1355         }
1356
1357         /* more room in the buffer for new writes, wakeup */
1358         if (tty)
1359                 tty_wakeup(tty);
1360         wake_up_interruptible(&tport->tp_write_wait);
1361 }
1362
1363
1364 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1365 {
1366         unsigned long flags;
1367         int status;
1368
1369         status = ti_write_byte(tport->tp_tdev,
1370                 tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1371                 TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1372
1373         spin_lock_irqsave(&tport->tp_lock, flags);
1374         if (!status)
1375                 tport->tp_shadow_mcr = mcr;
1376         spin_unlock_irqrestore(&tport->tp_lock, flags);
1377
1378         return status;
1379 }
1380
1381
1382 static int ti_get_lsr(struct ti_port *tport)
1383 {
1384         int size,status;
1385         struct ti_device *tdev = tport->tp_tdev;
1386         struct usb_serial_port *port = tport->tp_port;
1387         int port_number = port->number - port->serial->minor;
1388         struct ti_port_status *data;
1389
1390         dbg("%s - port %d", __FUNCTION__, port->number);
1391
1392         size = sizeof(struct ti_port_status);
1393         data = kmalloc(size, GFP_KERNEL);
1394         if (!data) {
1395                 dev_err(&port->dev, "%s - out of memory\n", __FUNCTION__);
1396                 return -ENOMEM;
1397         }
1398
1399         status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1400                 (__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1401         if (status) {
1402                 dev_err(&port->dev, "%s - get port status command failed, %d\n", __FUNCTION__, status);
1403                 goto free_data;
1404         }
1405
1406         dbg("%s - lsr 0x%02X", __FUNCTION__, data->bLSR);
1407
1408         tport->tp_lsr = data->bLSR;
1409
1410 free_data:
1411         kfree(data);
1412         return status;
1413 }
1414
1415
1416 static int ti_get_serial_info(struct ti_port *tport,
1417         struct serial_struct __user *ret_arg)
1418 {
1419         struct usb_serial_port *port = tport->tp_port;
1420         struct serial_struct ret_serial;
1421
1422         if (!ret_arg)
1423                 return -EFAULT;
1424
1425         memset(&ret_serial, 0, sizeof(ret_serial));
1426
1427         ret_serial.type = PORT_16550A;
1428         ret_serial.line = port->serial->minor;
1429         ret_serial.port = port->number - port->serial->minor;
1430         ret_serial.flags = tport->tp_flags;
1431         ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1432         ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1433         ret_serial.closing_wait = tport->tp_closing_wait;
1434
1435         if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1436                 return -EFAULT;
1437
1438         return 0;
1439 }
1440
1441
1442 static int ti_set_serial_info(struct ti_port *tport,
1443         struct serial_struct __user *new_arg)
1444 {
1445         struct usb_serial_port *port = tport->tp_port;
1446         struct serial_struct new_serial;
1447
1448         if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1449                 return -EFAULT;
1450
1451         tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1452         if (port->tty)
1453                 port->tty->low_latency =
1454                         (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1455         tport->tp_closing_wait = new_serial.closing_wait;
1456
1457         return 0;
1458 }
1459
1460
1461 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1462 {
1463         struct async_icount *icount;
1464         struct tty_struct *tty;
1465         unsigned long flags;
1466
1467         dbg("%s - msr 0x%02X", __FUNCTION__, msr);
1468
1469         if (msr & TI_MSR_DELTA_MASK) {
1470                 spin_lock_irqsave(&tport->tp_lock, flags);
1471                 icount = &tport->tp_icount;
1472                 if (msr & TI_MSR_DELTA_CTS)
1473                         icount->cts++;
1474                 if (msr & TI_MSR_DELTA_DSR)
1475                         icount->dsr++;
1476                 if (msr & TI_MSR_DELTA_CD)
1477                         icount->dcd++;
1478                 if (msr & TI_MSR_DELTA_RI)
1479                         icount->rng++;
1480                 wake_up_interruptible(&tport->tp_msr_wait);
1481                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1482         }
1483
1484         tport->tp_msr = msr & TI_MSR_MASK;
1485
1486         /* handle CTS flow control */
1487         tty = tport->tp_port->tty;
1488         if (tty && C_CRTSCTS(tty)) {
1489                 if (msr & TI_MSR_CTS) {
1490                         tty->hw_stopped = 0;
1491                         tty_wakeup(tty);
1492                 } else {
1493                         tty->hw_stopped = 1;
1494                 }
1495         }
1496 }
1497
1498
1499 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1500 {
1501         struct ti_device *tdev = tport->tp_tdev;
1502         struct usb_serial_port *port = tport->tp_port;
1503         wait_queue_t wait;
1504
1505         dbg("%s - port %d", __FUNCTION__, port->number);
1506
1507         spin_lock_irq(&tport->tp_lock);
1508
1509         /* wait for data to drain from the buffer */
1510         tdev->td_urb_error = 0;
1511         init_waitqueue_entry(&wait, current);
1512         add_wait_queue(&tport->tp_write_wait, &wait);
1513         for (;;) {
1514                 set_current_state(TASK_INTERRUPTIBLE);
1515                 if (ti_buf_data_avail(tport->tp_write_buf) == 0
1516                 || timeout == 0 || signal_pending(current)
1517                 || tdev->td_urb_error
1518                 || port->serial->disconnected)  /* disconnect */
1519                         break;
1520                 spin_unlock_irq(&tport->tp_lock);
1521                 timeout = schedule_timeout(timeout);
1522                 spin_lock_irq(&tport->tp_lock);
1523         }
1524         set_current_state(TASK_RUNNING);
1525         remove_wait_queue(&tport->tp_write_wait, &wait);
1526
1527         /* flush any remaining data in the buffer */
1528         if (flush)
1529                 ti_buf_clear(tport->tp_write_buf);
1530
1531         spin_unlock_irq(&tport->tp_lock);
1532
1533         mutex_lock(&port->serial->disc_mutex);
1534         /* wait for data to drain from the device */
1535         /* wait for empty tx register, plus 20 ms */
1536         timeout += jiffies;
1537         tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1538         while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1539         && !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1540         && !port->serial->disconnected) {
1541                 if (ti_get_lsr(tport))
1542                         break;
1543                 mutex_unlock(&port->serial->disc_mutex);
1544                 msleep_interruptible(20);
1545                 mutex_lock(&port->serial->disc_mutex);
1546         }
1547         mutex_unlock(&port->serial->disc_mutex);
1548 }
1549
1550
1551 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1552 {
1553         unsigned long flags;
1554
1555         spin_lock_irqsave(&tport->tp_lock, flags);
1556
1557         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1558                 tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1559
1560         spin_unlock_irqrestore(&tport->tp_lock, flags);
1561 }
1562
1563
1564 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1565 {
1566         struct urb *urb;
1567         int status = 0;
1568         unsigned long flags;
1569
1570         spin_lock_irqsave(&tport->tp_lock, flags);
1571
1572         if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1573                 tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1574                 urb = tport->tp_port->read_urb;
1575                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1576                 urb->complete = ti_bulk_in_callback;
1577                 urb->context = tport;
1578                 urb->dev = tport->tp_port->serial->dev;
1579                 status = usb_submit_urb(urb, GFP_KERNEL);
1580         } else  {
1581                 tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1582                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1583         }
1584
1585         return status;
1586 }
1587
1588
1589 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1590         __u16 moduleid, __u16 value, __u8 *data, int size)
1591 {
1592         int status;
1593
1594         status = usb_control_msg(tdev->td_serial->dev,
1595                 usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1596                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1597                 value, moduleid, data, size, 1000);
1598
1599         if (status == size)
1600                 status = 0;
1601
1602         if (status > 0)
1603                 status = -ECOMM;
1604
1605         return status;
1606 }
1607
1608
1609 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1610         __u16 moduleid, __u16 value, __u8 *data, int size)
1611 {
1612         int status;
1613
1614         status = usb_control_msg(tdev->td_serial->dev,
1615                 usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1616                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1617                 value, moduleid, data, size, 1000);
1618
1619         if (status == size)
1620                 status = 0;
1621
1622         if (status > 0)
1623                 status = -ECOMM;
1624
1625         return status;
1626 }
1627
1628
1629 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1630         __u8 mask, __u8 byte)
1631 {
1632         int status;
1633         unsigned int size;
1634         struct ti_write_data_bytes *data;
1635         struct device *dev = &tdev->td_serial->dev->dev;
1636
1637         dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X", __FUNCTION__, addr, mask, byte);
1638
1639         size = sizeof(struct ti_write_data_bytes) + 2;
1640         data = kmalloc(size, GFP_KERNEL);
1641         if (!data) {
1642                 dev_err(dev, "%s - out of memory\n", __FUNCTION__);
1643                 return -ENOMEM;
1644         }
1645
1646         data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1647         data->bDataType = TI_RW_DATA_BYTE;
1648         data->bDataCounter = 1;
1649         data->wBaseAddrHi = cpu_to_be16(addr>>16);
1650         data->wBaseAddrLo = cpu_to_be16(addr);
1651         data->bData[0] = mask;
1652         data->bData[1] = byte;
1653
1654         status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1655                 (__u8 *)data, size);
1656
1657         if (status < 0)
1658                 dev_err(dev, "%s - failed, %d\n", __FUNCTION__, status);
1659
1660         kfree(data);
1661
1662         return status;
1663 }
1664
1665
1666 static int ti_download_firmware(struct ti_device *tdev,
1667         unsigned char *firmware, unsigned int firmware_size)
1668 {
1669         int status = 0;
1670         int buffer_size;
1671         int pos;
1672         int len;
1673         int done;
1674         __u8 cs = 0;
1675         __u8 *buffer;
1676         struct usb_device *dev = tdev->td_serial->dev;
1677         struct ti_firmware_header *header;
1678         unsigned int pipe = usb_sndbulkpipe(dev,
1679                 tdev->td_serial->port[0]->bulk_out_endpointAddress);
1680
1681
1682         buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1683         buffer = kmalloc(buffer_size, GFP_KERNEL);
1684         if (!buffer) {
1685                 dev_err(&dev->dev, "%s - out of memory\n", __FUNCTION__);
1686                 return -ENOMEM;
1687         }
1688
1689         memcpy(buffer, firmware, firmware_size);
1690         memset(buffer+firmware_size, 0xff, buffer_size-firmware_size);
1691
1692         for(pos = sizeof(struct ti_firmware_header); pos < buffer_size; pos++)
1693                 cs = (__u8)(cs + buffer[pos]);
1694
1695         header = (struct ti_firmware_header *)buffer;
1696         header->wLength = cpu_to_le16((__u16)(buffer_size - sizeof(struct ti_firmware_header)));
1697         header->bCheckSum = cs;
1698
1699         dbg("%s - downloading firmware", __FUNCTION__);
1700         for (pos = 0; pos < buffer_size; pos += done) {
1701                 len = min(buffer_size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1702                 status = usb_bulk_msg(dev, pipe, buffer+pos, len, &done, 1000);
1703                 if (status)
1704                         break;
1705         }
1706
1707         kfree(buffer);
1708
1709         if (status) {
1710                 dev_err(&dev->dev, "%s - error downloading firmware, %d\n", __FUNCTION__, status);
1711                 return status;
1712         }
1713
1714         dbg("%s - download successful", __FUNCTION__);
1715
1716         return 0;
1717 }
1718
1719
1720 /* Circular Buffer Functions */
1721
1722 /*
1723  * ti_buf_alloc
1724  *
1725  * Allocate a circular buffer and all associated memory.
1726  */
1727
1728 static struct circ_buf *ti_buf_alloc(void)
1729 {
1730         struct circ_buf *cb;
1731
1732         cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1733         if (cb == NULL)
1734                 return NULL;
1735
1736         cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1737         if (cb->buf == NULL) {
1738                 kfree(cb);
1739                 return NULL;
1740         }
1741
1742         ti_buf_clear(cb);
1743
1744         return cb;
1745 }
1746
1747
1748 /*
1749  * ti_buf_free
1750  *
1751  * Free the buffer and all associated memory.
1752  */
1753
1754 static void ti_buf_free(struct circ_buf *cb)
1755 {
1756         kfree(cb->buf);
1757         kfree(cb);
1758 }
1759
1760
1761 /*
1762  * ti_buf_clear
1763  *
1764  * Clear out all data in the circular buffer.
1765  */
1766
1767 static void ti_buf_clear(struct circ_buf *cb)
1768 {
1769         cb->head = cb->tail = 0;
1770 }
1771
1772
1773 /*
1774  * ti_buf_data_avail
1775  *
1776  * Return the number of bytes of data available in the circular
1777  * buffer.
1778  */
1779
1780 static int ti_buf_data_avail(struct circ_buf *cb)
1781 {
1782         return CIRC_CNT(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1783 }
1784
1785
1786 /*
1787  * ti_buf_space_avail
1788  *
1789  * Return the number of bytes of space available in the circular
1790  * buffer.
1791  */
1792
1793 static int ti_buf_space_avail(struct circ_buf *cb)
1794 {
1795         return CIRC_SPACE(cb->head,cb->tail,TI_WRITE_BUF_SIZE);
1796 }
1797
1798
1799 /*
1800  * ti_buf_put
1801  *
1802  * Copy data data from a user buffer and put it into the circular buffer.
1803  * Restrict to the amount of space available.
1804  *
1805  * Return the number of bytes copied.
1806  */
1807
1808 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1809 {
1810         int c, ret = 0;
1811
1812         while (1) {
1813                 c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1814                 if (count < c)
1815                         c = count;
1816                 if (c <= 0)
1817                         break;
1818                 memcpy(cb->buf + cb->head, buf, c);
1819                 cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1820                 buf += c;
1821                 count -= c;
1822                 ret += c;
1823         }
1824
1825         return ret;
1826 }
1827
1828
1829 /*
1830  * ti_buf_get
1831  *
1832  * Get data from the circular buffer and copy to the given buffer.
1833  * Restrict to the amount of data available.
1834  *
1835  * Return the number of bytes copied.
1836  */
1837
1838 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1839 {
1840         int c, ret = 0;
1841
1842         while (1) {
1843                 c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1844                 if (count < c)
1845                         c = count;
1846                 if (c <= 0)
1847                         break;
1848                 memcpy(buf, cb->buf + cb->tail, c);
1849                 cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1850                 buf += c;
1851                 count -= c;
1852                 ret += c;
1853         }
1854
1855         return ret;
1856 }