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/firmware.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 <linux/mutex.h>
  85 #include <linux/uaccess.h>
  86 #include <linux/usb.h>
  87 #include <linux/usb/serial.h>
  88 #include <linux/firmware.h>
  89
  90 #include "ti_usb_3410_5052.h"
  91
  92 /* Defines */
  93
  94 #define TI_DRIVER_VERSION       "v0.9"
  95 #define TI_DRIVER_AUTHOR        "Al Borchers <alborchers@steinerpoint.com>"
  96 #define TI_DRIVER_DESC          "TI USB 3410/5052 Serial Driver"
  97
  98 #define TI_FIRMWARE_BUF_SIZE    16284
  99
 100 #define TI_WRITE_BUF_SIZE       1024
 101
 102 #define TI_TRANSFER_TIMEOUT     2
 103
 104 #define TI_DEFAULT_LOW_LATENCY  0
 105 #define TI_DEFAULT_CLOSING_WAIT 4000            /* in .01 secs */
 106
 107 /* supported setserial flags */
 108 #define TI_SET_SERIAL_FLAGS     (ASYNC_LOW_LATENCY)
 109
 110 /* read urb states */
 111 #define TI_READ_URB_RUNNING     0
 112 #define TI_READ_URB_STOPPING    1
 113 #define TI_READ_URB_STOPPED     2
 114
 115 #define TI_EXTRA_VID_PID_COUNT  5
 116
 117
 118 /* Structures */
 119
 120 struct ti_port {
 121         int                     tp_is_open;
 122         __u8                    tp_msr;
 123         __u8                    tp_lsr;
 124         __u8                    tp_shadow_mcr;
 125         __u8                    tp_uart_mode;   /* 232 or 485 modes */
 126         unsigned int            tp_uart_base_addr;
 127         int                     tp_flags;
 128         int                     tp_closing_wait;/* in .01 secs */
 129         struct async_icount     tp_icount;
 130         wait_queue_head_t       tp_msr_wait;    /* wait for msr change */
 131         wait_queue_head_t       tp_write_wait;
 132         struct ti_device        *tp_tdev;
 133         struct usb_serial_port  *tp_port;
 134         spinlock_t              tp_lock;
 135         int                     tp_read_urb_state;
 136         int                     tp_write_urb_in_use;
 137         struct circ_buf         *tp_write_buf;
 138 };
 139
 140 struct ti_device {
 141         struct mutex            td_open_close_lock;
 142         int                     td_open_port_count;
 143         struct usb_serial       *td_serial;
 144         int                     td_is_3410;
 145         int                     td_urb_error;
 146 };
 147
 148
 149 /* Function Declarations */
 150
 151 static int ti_startup(struct usb_serial *serial);
 152 static void ti_shutdown(struct usb_serial *serial);
 153 static int ti_open(struct tty_struct *tty, struct usb_serial_port *port,
 154                 struct file *file);
 155 static void ti_close(struct tty_struct *tty, struct usb_serial_port *port,
 156                 struct file *file);
 157 static int ti_write(struct tty_struct *tty, struct usb_serial_port *port,
 158                 const unsigned char *data, int count);
 159 static int ti_write_room(struct tty_struct *tty);
 160 static int ti_chars_in_buffer(struct tty_struct *tty);
 161 static void ti_throttle(struct tty_struct *tty);
 162 static void ti_unthrottle(struct tty_struct *tty);
 163 static int ti_ioctl(struct tty_struct *tty, struct file *file,
 164                 unsigned int cmd, unsigned long arg);
 165 static void ti_set_termios(struct tty_struct *tty,
 166                 struct usb_serial_port *port, struct ktermios *old_termios);
 167 static int ti_tiocmget(struct tty_struct *tty, struct file *file);
 168 static int ti_tiocmset(struct tty_struct *tty, struct file *file,
 169                 unsigned int set, unsigned int clear);
 170 static void ti_break(struct tty_struct *tty, int break_state);
 171 static void ti_interrupt_callback(struct urb *urb);
 172 static void ti_bulk_in_callback(struct urb *urb);
 173 static void ti_bulk_out_callback(struct urb *urb);
 174
 175 static void ti_recv(struct device *dev, struct tty_struct *tty,
 176         unsigned char *data, int length);
 177 static void ti_send(struct ti_port *tport);
 178 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
 179 static int ti_get_lsr(struct ti_port *tport);
 180 static int ti_get_serial_info(struct ti_port *tport,
 181         struct serial_struct __user *ret_arg);
 182 static int ti_set_serial_info(struct ti_port *tport,
 183         struct serial_struct __user *new_arg);
 184 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
 185
 186 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
 187
 188 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
 189 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
 190
 191 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
 192         __u16 moduleid, __u16 value, __u8 *data, int size);
 193 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
 194         __u16 moduleid, __u16 value, __u8 *data, int size);
 195
 196 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
 197         __u8 mask, __u8 byte);
 198
 199 static int ti_download_firmware(struct ti_device *tdev, int type);
 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 unsigned int vendor_3410_count;
 219 static ushort product_3410[TI_EXTRA_VID_PID_COUNT];
 220 static unsigned int product_3410_count;
 221 static ushort vendor_5052[TI_EXTRA_VID_PID_COUNT];
 222 static unsigned int vendor_5052_count;
 223 static ushort product_5052[TI_EXTRA_VID_PID_COUNT];
 224 static unsigned 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         { USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
 233 };
 234
 235 static struct usb_device_id ti_id_table_5052[4+TI_EXTRA_VID_PID_COUNT+1] = {
 236         { USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
 237         { USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
 238         { USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
 239         { USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
 240 };
 241
 242 static struct usb_device_id ti_id_table_combined[] = {
 243         { USB_DEVICE(TI_VENDOR_ID, TI_3410_PRODUCT_ID) },
 244         { USB_DEVICE(TI_VENDOR_ID, TI_3410_EZ430_ID) },
 245         { USB_DEVICE(TI_VENDOR_ID, TI_5052_BOOT_PRODUCT_ID) },
 246         { USB_DEVICE(TI_VENDOR_ID, TI_5152_BOOT_PRODUCT_ID) },
 247         { USB_DEVICE(TI_VENDOR_ID, TI_5052_EEPROM_PRODUCT_ID) },
 248         { USB_DEVICE(TI_VENDOR_ID, TI_5052_FIRMWARE_PRODUCT_ID) },
 249         { }
 250 };
 251
 252 static struct usb_driver ti_usb_driver = {
 253         .name                   = "ti_usb_3410_5052",
 254         .probe                  = usb_serial_probe,
 255         .disconnect             = usb_serial_disconnect,
 256         .id_table               = ti_id_table_combined,
 257         .no_dynamic_id =        1,
 258 };
 259
 260 static struct usb_serial_driver ti_1port_device = {
 261         .driver = {
 262                 .owner          = THIS_MODULE,
 263                 .name           = "ti_usb_3410_5052_1",
 264         },
 265         .description            = "TI USB 3410 1 port adapter",
 266         .usb_driver             = &ti_usb_driver,
 267         .id_table               = ti_id_table_3410,
 268         .num_ports              = 1,
 269         .attach                 = ti_startup,
 270         .shutdown               = ti_shutdown,
 271         .open                   = ti_open,
 272         .close                  = ti_close,
 273         .write                  = ti_write,
 274         .write_room             = ti_write_room,
 275         .chars_in_buffer        = ti_chars_in_buffer,
 276         .throttle               = ti_throttle,
 277         .unthrottle             = ti_unthrottle,
 278         .ioctl                  = ti_ioctl,
 279         .set_termios            = ti_set_termios,
 280         .tiocmget               = ti_tiocmget,
 281         .tiocmset               = ti_tiocmset,
 282         .break_ctl              = ti_break,
 283         .read_int_callback      = ti_interrupt_callback,
 284         .read_bulk_callback     = ti_bulk_in_callback,
 285         .write_bulk_callback    = ti_bulk_out_callback,
 286 };
 287
 288 static struct usb_serial_driver ti_2port_device = {
 289         .driver = {
 290                 .owner          = THIS_MODULE,
 291                 .name           = "ti_usb_3410_5052_2",
 292         },
 293         .description            = "TI USB 5052 2 port adapter",
 294         .usb_driver             = &ti_usb_driver,
 295         .id_table               = ti_id_table_5052,
 296         .num_ports              = 2,
 297         .attach                 = ti_startup,
 298         .shutdown               = ti_shutdown,
 299         .open                   = ti_open,
 300         .close                  = ti_close,
 301         .write                  = ti_write,
 302         .write_room             = ti_write_room,
 303         .chars_in_buffer        = ti_chars_in_buffer,
 304         .throttle               = ti_throttle,
 305         .unthrottle             = ti_unthrottle,
 306         .ioctl                  = ti_ioctl,
 307         .set_termios            = ti_set_termios,
 308         .tiocmget               = ti_tiocmget,
 309         .tiocmset               = ti_tiocmset,
 310         .break_ctl              = ti_break,
 311         .read_int_callback      = ti_interrupt_callback,
 312         .read_bulk_callback     = ti_bulk_in_callback,
 313         .write_bulk_callback    = ti_bulk_out_callback,
 314 };
 315
 316
 317 /* Module */
 318
 319 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
 320 MODULE_DESCRIPTION(TI_DRIVER_DESC);
 321 MODULE_VERSION(TI_DRIVER_VERSION);
 322 MODULE_LICENSE("GPL");
 323
 324 MODULE_FIRMWARE("ti_3410.fw");
 325 MODULE_FIRMWARE("ti_5052.fw");
 326
 327 module_param(debug, bool, S_IRUGO | S_IWUSR);
 328 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
 329
 330 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
 331 MODULE_PARM_DESC(low_latency,
 332                 "TTY low_latency flag, 0=off, 1=on, default is off");
 333
 334 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
 335 MODULE_PARM_DESC(closing_wait,
 336     "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,
 340                 "Vendor ids for 3410 based devices, 1-5 short integers");
 341 module_param_array(product_3410, ushort, &product_3410_count, S_IRUGO);
 342 MODULE_PARM_DESC(product_3410,
 343                 "Product ids for 3410 based devices, 1-5 short integers");
 344 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
 345 MODULE_PARM_DESC(vendor_5052,
 346                 "Vendor ids for 5052 based devices, 1-5 short integers");
 347 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
 348 MODULE_PARM_DESC(product_5052,
 349                 "Product ids for 5052 based devices, 1-5 short integers");
 350
 351 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
 352
 353
 354 /* Functions */
 355
 356 static int __init ti_init(void)
 357 {
 358         int i, j;
 359         int ret;
 360
 361         /* insert extra vendor and product ids */
 362         j = ARRAY_SIZE(ti_id_table_3410) - TI_EXTRA_VID_PID_COUNT - 1;
 363         for (i = 0; i < min(vendor_3410_count, product_3410_count); i++, j++) {
 364                 ti_id_table_3410[j].idVendor = vendor_3410[i];
 365                 ti_id_table_3410[j].idProduct = product_3410[i];
 366                 ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 367         }
 368         j = ARRAY_SIZE(ti_id_table_5052) - TI_EXTRA_VID_PID_COUNT - 1;
 369         for (i = 0; i < min(vendor_5052_count, product_5052_count); i++, j++) {
 370                 ti_id_table_5052[j].idVendor = vendor_5052[i];
 371                 ti_id_table_5052[j].idProduct = product_5052[i];
 372                 ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 373         }
 374
 375         ret = usb_serial_register(&ti_1port_device);
 376         if (ret)
 377                 goto failed_1port;
 378         ret = usb_serial_register(&ti_2port_device);
 379         if (ret)
 380                 goto failed_2port;
 381
 382         ret = usb_register(&ti_usb_driver);
 383         if (ret)
 384                 goto failed_usb;
 385
 386         info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
 387
 388         return 0;
 389
 390 failed_usb:
 391         usb_serial_deregister(&ti_2port_device);
 392 failed_2port:
 393         usb_serial_deregister(&ti_1port_device);
 394 failed_1port:
 395         return ret;
 396 }
 397
 398
 399 static void __exit ti_exit(void)
 400 {
 401         usb_serial_deregister(&ti_1port_device);
 402         usb_serial_deregister(&ti_2port_device);
 403         usb_deregister(&ti_usb_driver);
 404 }
 405
 406
 407 module_init(ti_init);
 408 module_exit(ti_exit);
 409
 410
 411 static int ti_startup(struct usb_serial *serial)
 412 {
 413         struct ti_device *tdev;
 414         struct ti_port *tport;
 415         struct usb_device *dev = serial->dev;
 416         int status;
 417         int i;
 418
 419
 420         dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
 421             __func__, le16_to_cpu(dev->descriptor.idProduct),
 422             dev->descriptor.bNumConfigurations,
 423             dev->actconfig->desc.bConfigurationValue);
 424
 425         /* create device structure */
 426         tdev = kzalloc(sizeof(struct ti_device), GFP_KERNEL);
 427         if (tdev == NULL) {
 428                 dev_err(&dev->dev, "%s - out of memory\n", __func__);
 429                 return -ENOMEM;
 430         }
 431         mutex_init(&tdev->td_open_close_lock);
 432         tdev->td_serial = serial;
 433         usb_set_serial_data(serial, tdev);
 434
 435         /* determine device type */
 436         if (usb_match_id(serial->interface, ti_id_table_3410))
 437                 tdev->td_is_3410 = 1;
 438         dbg("%s - device type is %s", __func__,
 439                                 tdev->td_is_3410 ? "3410" : "5052");
 440
 441         /* if we have only 1 configuration, download firmware */
 442         if (dev->descriptor.bNumConfigurations == 1) {
 443                 if (tdev->td_is_3410)
 444                         status = ti_download_firmware(tdev, 3410);
 445                 else
 446                         status = ti_download_firmware(tdev, 5052);
 447                 if (status)
 448                         goto free_tdev;
 449
 450                 /* 3410 must be reset, 5052 resets itself */
 451                 if (tdev->td_is_3410) {
 452                         msleep_interruptible(100);
 453                         usb_reset_device(dev);
 454                 }
 455
 456                 status = -ENODEV;
 457                 goto free_tdev;
 458         }
 459
 460         /* the second configuration must be set (in sysfs by hotplug script) */
 461         if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
 462                 status = -ENODEV;
 463                 goto free_tdev;
 464         }
 465
 466         /* set up port structures */
 467         for (i = 0; i < serial->num_ports; ++i) {
 468                 tport = kzalloc(sizeof(struct ti_port), GFP_KERNEL);
 469                 if (tport == NULL) {
 470                         dev_err(&dev->dev, "%s - out of memory\n", __func__);
 471                         status = -ENOMEM;
 472                         goto free_tports;
 473                 }
 474                 spin_lock_init(&tport->tp_lock);
 475                 tport->tp_uart_base_addr = (i == 0 ?
 476                                 TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
 477                 tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
 478                 tport->tp_closing_wait = closing_wait;
 479                 init_waitqueue_head(&tport->tp_msr_wait);
 480                 init_waitqueue_head(&tport->tp_write_wait);
 481                 tport->tp_write_buf = ti_buf_alloc();
 482                 if (tport->tp_write_buf == NULL) {
 483                         dev_err(&dev->dev, "%s - out of memory\n", __func__);
 484                         kfree(tport);
 485                         status = -ENOMEM;
 486                         goto free_tports;
 487                 }
 488                 tport->tp_port = serial->port[i];
 489                 tport->tp_tdev = tdev;
 490                 usb_set_serial_port_data(serial->port[i], tport);
 491                 tport->tp_uart_mode = 0;        /* default is RS232 */
 492         }
 493
 494         return 0;
 495
 496 free_tports:
 497         for (--i; i >= 0; --i) {
 498                 tport = usb_get_serial_port_data(serial->port[i]);
 499                 ti_buf_free(tport->tp_write_buf);
 500                 kfree(tport);
 501                 usb_set_serial_port_data(serial->port[i], NULL);
 502         }
 503 free_tdev:
 504         kfree(tdev);
 505         usb_set_serial_data(serial, NULL);
 506         return status;
 507 }
 508
 509
 510 static void ti_shutdown(struct usb_serial *serial)
 511 {
 512         int i;
 513         struct ti_device *tdev = usb_get_serial_data(serial);
 514         struct ti_port *tport;
 515
 516         dbg("%s", __func__);
 517
 518         for (i = 0; i < serial->num_ports; ++i) {
 519                 tport = usb_get_serial_port_data(serial->port[i]);
 520                 if (tport) {
 521                         ti_buf_free(tport->tp_write_buf);
 522                         kfree(tport);
 523                         usb_set_serial_port_data(serial->port[i], NULL);
 524                 }
 525         }
 526
 527         kfree(tdev);
 528         usb_set_serial_data(serial, NULL);
 529 }
 530
 531
 532 static int ti_open(struct tty_struct *tty,
 533                         struct usb_serial_port *port, struct file *file)
 534 {
 535         struct ti_port *tport = usb_get_serial_port_data(port);
 536         struct ti_device *tdev;
 537         struct usb_device *dev;
 538         struct urb *urb;
 539         int port_number;
 540         int status;
 541         __u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
 542                              TI_PIPE_TIMEOUT_ENABLE |
 543                              (TI_TRANSFER_TIMEOUT << 2));
 544
 545         dbg("%s - port %d", __func__, port->number);
 546
 547         if (tport == NULL)
 548                 return -ENODEV;
 549
 550         dev = port->serial->dev;
 551         tdev = tport->tp_tdev;
 552
 553         /* only one open on any port on a device at a time */
 554         if (mutex_lock_interruptible(&tdev->td_open_close_lock))
 555                 return -ERESTARTSYS;
 556
 557         if (tty)
 558                 tty->low_latency =
 559                                 (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 560
 561         port_number = port->number - port->serial->minor;
 562
 563         memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
 564
 565         tport->tp_msr = 0;
 566         tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
 567
 568         /* start interrupt urb the first time a port is opened on this device */
 569         if (tdev->td_open_port_count == 0) {
 570                 dbg("%s - start interrupt in urb", __func__);
 571                 urb = tdev->td_serial->port[0]->interrupt_in_urb;
 572                 if (!urb) {
 573                         dev_err(&port->dev, "%s - no interrupt urb\n",
 574                                                                 __func__);
 575                         status = -EINVAL;
 576                         goto release_lock;
 577                 }
 578                 urb->complete = ti_interrupt_callback;
 579                 urb->context = tdev;
 580                 urb->dev = dev;
 581                 status = usb_submit_urb(urb, GFP_KERNEL);
 582                 if (status) {
 583                         dev_err(&port->dev,
 584                                 "%s - submit interrupt urb failed, %d\n",
 585                                         __func__, status);
 586                         goto release_lock;
 587                 }
 588         }
 589
 590         if (tty)
 591                 ti_set_termios(tty, port, tty->termios);
 592
 593         dbg("%s - sending TI_OPEN_PORT", __func__);
 594         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 595                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 596         if (status) {
 597                 dev_err(&port->dev, "%s - cannot send open command, %d\n",
 598                                                         __func__, status);
 599                 goto unlink_int_urb;
 600         }
 601
 602         dbg("%s - sending TI_START_PORT", __func__);
 603         status = ti_command_out_sync(tdev, TI_START_PORT,
 604                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 605         if (status) {
 606                 dev_err(&port->dev, "%s - cannot send start command, %d\n",
 607                                                         __func__, status);
 608                 goto unlink_int_urb;
 609         }
 610
 611         dbg("%s - sending TI_PURGE_PORT", __func__);
 612         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 613                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
 614         if (status) {
 615                 dev_err(&port->dev, "%s - cannot clear input buffers, %d\n",
 616                                                         __func__, status);
 617                 goto unlink_int_urb;
 618         }
 619         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 620                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
 621         if (status) {
 622                 dev_err(&port->dev, "%s - cannot clear output buffers, %d\n",
 623                                                         __func__, status);
 624                 goto unlink_int_urb;
 625         }
 626
 627         /* reset the data toggle on the bulk endpoints to work around bug in
 628          * host controllers where things get out of sync some times */
 629         usb_clear_halt(dev, port->write_urb->pipe);
 630         usb_clear_halt(dev, port->read_urb->pipe);
 631
 632         if (tty)
 633                 ti_set_termios(tty, port, tty->termios);
 634
 635         dbg("%s - sending TI_OPEN_PORT (2)", __func__);
 636         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 637                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 638         if (status) {
 639                 dev_err(&port->dev, "%s - cannot send open command (2), %d\n",
 640                                                         __func__, status);
 641                 goto unlink_int_urb;
 642         }
 643
 644         dbg("%s - sending TI_START_PORT (2)", __func__);
 645         status = ti_command_out_sync(tdev, TI_START_PORT,
 646                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 647         if (status) {
 648                 dev_err(&port->dev, "%s - cannot send start command (2), %d\n",
 649                                                         __func__, status);
 650                 goto unlink_int_urb;
 651         }
 652
 653         /* start read urb */
 654         dbg("%s - start read urb", __func__);
 655         urb = port->read_urb;
 656         if (!urb) {
 657                 dev_err(&port->dev, "%s - no read urb\n", __func__);
 658                 status = -EINVAL;
 659                 goto unlink_int_urb;
 660         }
 661         tport->tp_read_urb_state = TI_READ_URB_RUNNING;
 662         urb->complete = ti_bulk_in_callback;
 663         urb->context = tport;
 664         urb->dev = dev;
 665         status = usb_submit_urb(urb, GFP_KERNEL);
 666         if (status) {
 667                 dev_err(&port->dev, "%s - submit read urb failed, %d\n",
 668                                                         __func__, status);
 669                 goto unlink_int_urb;
 670         }
 671
 672         tport->tp_is_open = 1;
 673         ++tdev->td_open_port_count;
 674
 675         goto release_lock;
 676
 677 unlink_int_urb:
 678         if (tdev->td_open_port_count == 0)
 679                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 680 release_lock:
 681         mutex_unlock(&tdev->td_open_close_lock);
 682         dbg("%s - exit %d", __func__, status);
 683         return status;
 684 }
 685
 686
 687 static void ti_close(struct tty_struct *tty, struct usb_serial_port *port,
 688                                                         struct file *file)
 689 {
 690         struct ti_device *tdev;
 691         struct ti_port *tport;
 692         int port_number;
 693         int status;
 694         int do_unlock;
 695
 696         dbg("%s - port %d", __func__, port->number);
 697
 698         tdev = usb_get_serial_data(port->serial);
 699         tport = usb_get_serial_port_data(port);
 700         if (tdev == NULL || tport == NULL)
 701                 return;
 702
 703         tport->tp_is_open = 0;
 704
 705         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
 706
 707         usb_kill_urb(port->read_urb);
 708         usb_kill_urb(port->write_urb);
 709         tport->tp_write_urb_in_use = 0;
 710
 711         port_number = port->number - port->serial->minor;
 712
 713         dbg("%s - sending TI_CLOSE_PORT", __func__);
 714         status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
 715                      (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 716         if (status)
 717                 dev_err(&port->dev,
 718                         "%s - cannot send close port command, %d\n"
 719                                                         , __func__, status);
 720
 721         /* if mutex_lock is interrupted, continue anyway */
 722         do_unlock = !mutex_lock_interruptible(&tdev->td_open_close_lock);
 723         --tport->tp_tdev->td_open_port_count;
 724         if (tport->tp_tdev->td_open_port_count <= 0) {
 725                 /* last port is closed, shut down interrupt urb */
 726                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 727                 tport->tp_tdev->td_open_port_count = 0;
 728         }
 729         if (do_unlock)
 730                 mutex_unlock(&tdev->td_open_close_lock);
 731
 732         dbg("%s - exit", __func__);
 733 }
 734
 735
 736 static int ti_write(struct tty_struct *tty, struct usb_serial_port *port,
 737                         const unsigned char *data, int count)
 738 {
 739         struct ti_port *tport = usb_get_serial_port_data(port);
 740         unsigned long flags;
 741
 742         dbg("%s - port %d", __func__, port->number);
 743
 744         if (count == 0) {
 745                 dbg("%s - write request of 0 bytes", __func__);
 746                 return 0;
 747         }
 748
 749         if (tport == NULL || !tport->tp_is_open)
 750                 return -ENODEV;
 751
 752         spin_lock_irqsave(&tport->tp_lock, flags);
 753         count = ti_buf_put(tport->tp_write_buf, data, count);
 754         spin_unlock_irqrestore(&tport->tp_lock, flags);
 755
 756         ti_send(tport);
 757
 758         return count;
 759 }
 760
 761
 762 static int ti_write_room(struct tty_struct *tty)
 763 {
 764         struct usb_serial_port *port = tty->driver_data;
 765         struct ti_port *tport = usb_get_serial_port_data(port);
 766         int room = 0;
 767         unsigned long flags;
 768
 769         dbg("%s - port %d", __func__, port->number);
 770
 771         if (tport == NULL)
 772                 return -ENODEV;
 773
 774         spin_lock_irqsave(&tport->tp_lock, flags);
 775         room = ti_buf_space_avail(tport->tp_write_buf);
 776         spin_unlock_irqrestore(&tport->tp_lock, flags);
 777
 778         dbg("%s - returns %d", __func__, room);
 779         return room;
 780 }
 781
 782
 783 static int ti_chars_in_buffer(struct tty_struct *tty)
 784 {
 785         struct usb_serial_port *port = tty->driver_data;
 786         struct ti_port *tport = usb_get_serial_port_data(port);
 787         int chars = 0;
 788         unsigned long flags;
 789
 790         dbg("%s - port %d", __func__, port->number);
 791
 792         if (tport == NULL)
 793                 return -ENODEV;
 794
 795         spin_lock_irqsave(&tport->tp_lock, flags);
 796         chars = ti_buf_data_avail(tport->tp_write_buf);
 797         spin_unlock_irqrestore(&tport->tp_lock, flags);
 798
 799         dbg("%s - returns %d", __func__, chars);
 800         return chars;
 801 }
 802
 803
 804 static void ti_throttle(struct tty_struct *tty)
 805 {
 806         struct usb_serial_port *port = tty->driver_data;
 807         struct ti_port *tport = usb_get_serial_port_data(port);
 808
 809         dbg("%s - port %d", __func__, port->number);
 810
 811         if (tport == NULL)
 812                 return;
 813
 814         if (I_IXOFF(tty) || C_CRTSCTS(tty))
 815                 ti_stop_read(tport, tty);
 816
 817 }
 818
 819
 820 static void ti_unthrottle(struct tty_struct *tty)
 821 {
 822         struct usb_serial_port *port = tty->driver_data;
 823         struct ti_port *tport = usb_get_serial_port_data(port);
 824         int status;
 825
 826         dbg("%s - port %d", __func__, port->number);
 827
 828         if (tport == NULL)
 829                 return;
 830
 831         if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
 832                 status = ti_restart_read(tport, tty);
 833                 if (status)
 834                         dev_err(&port->dev, "%s - cannot restart read, %d\n",
 835                                                         __func__, status);
 836         }
 837 }
 838
 839
 840 static int ti_ioctl(struct tty_struct *tty, struct file *file,
 841         unsigned int cmd, unsigned long arg)
 842 {
 843         struct usb_serial_port *port = tty->driver_data;
 844         struct ti_port *tport = usb_get_serial_port_data(port);
 845         struct async_icount cnow;
 846         struct async_icount cprev;
 847
 848         dbg("%s - port %d, cmd = 0x%04X", __func__, port->number, cmd);
 849
 850         if (tport == NULL)
 851                 return -ENODEV;
 852
 853         switch (cmd) {
 854         case TIOCGSERIAL:
 855                 dbg("%s - (%d) TIOCGSERIAL", __func__, port->number);
 856                 return ti_get_serial_info(tport,
 857                                 (struct serial_struct __user *)arg);
 858         case TIOCSSERIAL:
 859                 dbg("%s - (%d) TIOCSSERIAL", __func__, port->number);
 860                 return ti_set_serial_info(tport,
 861                                         (struct serial_struct __user *)arg);
 862         case TIOCMIWAIT:
 863                 dbg("%s - (%d) TIOCMIWAIT", __func__, port->number);
 864                 cprev = tport->tp_icount;
 865                 while (1) {
 866                         interruptible_sleep_on(&tport->tp_msr_wait);
 867                         if (signal_pending(current))
 868                                 return -ERESTARTSYS;
 869                         cnow = tport->tp_icount;
 870                         if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
 871                             cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
 872                                 return -EIO; /* no change => error */
 873                         if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 874                             ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 875                             ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
 876                             ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)))
 877                                 return 0;
 878                         cprev = cnow;
 879                 }
 880                 break;
 881         case TIOCGICOUNT:
 882                 dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d",
 883                                 __func__, port->number,
 884                                 tport->tp_icount.rx, tport->tp_icount.tx);
 885                 if (copy_to_user((void __user *)arg, &tport->tp_icount,
 886                                         sizeof(tport->tp_icount)))
 887                         return -EFAULT;
 888                 return 0;
 889         }
 890         return -ENOIOCTLCMD;
 891 }
 892
 893
 894 static void ti_set_termios(struct tty_struct *tty,
 895                 struct usb_serial_port *port, struct ktermios *old_termios)
 896 {
 897         struct ti_port *tport = usb_get_serial_port_data(port);
 898         struct ti_uart_config *config;
 899         tcflag_t cflag, iflag;
 900         int baud;
 901         int status;
 902         int port_number = port->number - port->serial->minor;
 903         unsigned int mcr;
 904
 905         dbg("%s - port %d", __func__, port->number);
 906
 907         cflag = tty->termios->c_cflag;
 908         iflag = tty->termios->c_iflag;
 909
 910         dbg("%s - cflag %08x, iflag %08x", __func__, cflag, iflag);
 911         dbg("%s - old clfag %08x, old iflag %08x", __func__,
 912                                 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", __func__);
 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         /* CMSPAR isn't supported by this driver */
 947         tty->termios->c_cflag &= ~CMSPAR;
 948
 949         if (cflag & PARENB) {
 950                 if (cflag & PARODD) {
 951                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 952                         config->bParity = TI_UART_ODD_PARITY;
 953                 } else {
 954                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 955                         config->bParity = TI_UART_EVEN_PARITY;
 956                 }
 957         } else {
 958                 config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
 959                 config->bParity = TI_UART_NO_PARITY;
 960         }
 961
 962         if (cflag & CSTOPB)
 963                 config->bStopBits = TI_UART_2_STOP_BITS;
 964         else
 965                 config->bStopBits = TI_UART_1_STOP_BITS;
 966
 967         if (cflag & CRTSCTS) {
 968                 /* RTS flow control must be off to drop RTS for baud rate B0 */
 969                 if ((cflag & CBAUD) != B0)
 970                         config->wFlags |= TI_UART_ENABLE_RTS_IN;
 971                 config->wFlags |= TI_UART_ENABLE_CTS_OUT;
 972         } else {
 973                 tty->hw_stopped = 0;
 974                 ti_restart_read(tport, tty);
 975         }
 976
 977         if (I_IXOFF(tty) || I_IXON(tty)) {
 978                 config->cXon  = START_CHAR(tty);
 979                 config->cXoff = STOP_CHAR(tty);
 980
 981                 if (I_IXOFF(tty))
 982                         config->wFlags |= TI_UART_ENABLE_X_IN;
 983                 else
 984                         ti_restart_read(tport, tty);
 985
 986                 if (I_IXON(tty))
 987                         config->wFlags |= TI_UART_ENABLE_X_OUT;
 988         }
 989
 990         baud = tty_get_baud_rate(tty);
 991         if (!baud)
 992                 baud = 9600;
 993         if (tport->tp_tdev->td_is_3410)
 994                 config->wBaudRate = (__u16)((923077 + baud/2) / baud);
 995         else
 996                 config->wBaudRate = (__u16)((461538 + baud/2) / baud);
 997
 998         /* FIXME: Should calculate resulting baud here and report it back */
 999         if ((cflag & CBAUD) != B0)
1000                 tty_encode_baud_rate(tty, baud, baud);
1001
1002         dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
1003         __func__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
1004
1005         cpu_to_be16s(&config->wBaudRate);
1006         cpu_to_be16s(&config->wFlags);
1007
1008         status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1009                 (__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1010                 sizeof(*config));
1011         if (status)
1012                 dev_err(&port->dev, "%s - cannot set config on port %d, %d\n",
1013                                         __func__, port_number, status);
1014
1015         /* SET_CONFIG asserts RTS and DTR, reset them correctly */
1016         mcr = tport->tp_shadow_mcr;
1017         /* if baud rate is B0, clear RTS and DTR */
1018         if ((cflag & CBAUD) == B0)
1019                 mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1020         status = ti_set_mcr(tport, mcr);
1021         if (status)
1022                 dev_err(&port->dev,
1023                         "%s - cannot set modem control on port %d, %d\n",
1024                                                 __func__, port_number, status);
1025
1026         kfree(config);
1027 }
1028
1029
1030 static int ti_tiocmget(struct tty_struct *tty, struct file *file)
1031 {
1032         struct usb_serial_port *port = tty->driver_data;
1033         struct ti_port *tport = usb_get_serial_port_data(port);
1034         unsigned int result;
1035         unsigned int msr;
1036         unsigned int mcr;
1037         unsigned long flags;
1038
1039         dbg("%s - port %d", __func__, port->number);
1040
1041         if (tport == NULL)
1042                 return -ENODEV;
1043
1044         spin_lock_irqsave(&tport->tp_lock, flags);
1045         msr = tport->tp_msr;
1046         mcr = tport->tp_shadow_mcr;
1047         spin_unlock_irqrestore(&tport->tp_lock, flags);
1048
1049         result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1050                 | ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1051                 | ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1052                 | ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1053                 | ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1054                 | ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1055                 | ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1056
1057         dbg("%s - 0x%04X", __func__, result);
1058
1059         return result;
1060 }
1061
1062
1063 static int ti_tiocmset(struct tty_struct *tty, struct file *file,
1064         unsigned int set, unsigned int clear)
1065 {
1066         struct usb_serial_port *port = tty->driver_data;
1067         struct ti_port *tport = usb_get_serial_port_data(port);
1068         unsigned int mcr;
1069         unsigned long flags;
1070
1071         dbg("%s - port %d", __func__, port->number);
1072
1073         if (tport == NULL)
1074                 return -ENODEV;
1075
1076         spin_lock_irqsave(&tport->tp_lock, flags);
1077         mcr = tport->tp_shadow_mcr;
1078
1079         if (set & TIOCM_RTS)
1080                 mcr |= TI_MCR_RTS;
1081         if (set & TIOCM_DTR)
1082                 mcr |= TI_MCR_DTR;
1083         if (set & TIOCM_LOOP)
1084                 mcr |= TI_MCR_LOOP;
1085
1086         if (clear & TIOCM_RTS)
1087                 mcr &= ~TI_MCR_RTS;
1088         if (clear & TIOCM_DTR)
1089                 mcr &= ~TI_MCR_DTR;
1090         if (clear & TIOCM_LOOP)
1091                 mcr &= ~TI_MCR_LOOP;
1092         spin_unlock_irqrestore(&tport->tp_lock, flags);
1093
1094         return ti_set_mcr(tport, mcr);
1095 }
1096
1097
1098 static void ti_break(struct tty_struct *tty, int break_state)
1099 {
1100         struct usb_serial_port *port = tty->driver_data;
1101         struct ti_port *tport = usb_get_serial_port_data(port);
1102         int status;
1103
1104         dbg("%s - state = %d", __func__, break_state);
1105
1106         if (tport == NULL)
1107                 return;
1108
1109         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1110
1111         status = ti_write_byte(tport->tp_tdev,
1112                 tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1113                 TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1114
1115         if (status)
1116                 dbg("%s - error setting break, %d", __func__, status);
1117 }
1118
1119
1120 static void ti_interrupt_callback(struct urb *urb)
1121 {
1122         struct ti_device *tdev = urb->context;
1123         struct usb_serial_port *port;
1124         struct usb_serial *serial = tdev->td_serial;
1125         struct ti_port *tport;
1126         struct device *dev = &urb->dev->dev;
1127         unsigned char *data = urb->transfer_buffer;
1128         int length = urb->actual_length;
1129         int port_number;
1130         int function;
1131         int status = urb->status;
1132         int retval;
1133         __u8 msr;
1134
1135         dbg("%s", __func__);
1136
1137         switch (status) {
1138         case 0:
1139                 break;
1140         case -ECONNRESET:
1141         case -ENOENT:
1142         case -ESHUTDOWN:
1143                 dbg("%s - urb shutting down, %d", __func__, status);
1144                 tdev->td_urb_error = 1;
1145                 return;
1146         default:
1147                 dev_err(dev, "%s - nonzero urb status, %d\n",
1148                         __func__, status);
1149                 tdev->td_urb_error = 1;
1150                 goto exit;
1151         }
1152
1153         if (length != 2) {
1154                 dbg("%s - bad packet size, %d", __func__, length);
1155                 goto exit;
1156         }
1157
1158         if (data[0] == TI_CODE_HARDWARE_ERROR) {
1159                 dev_err(dev, "%s - hardware error, %d\n", __func__, data[1]);
1160                 goto exit;
1161         }
1162
1163         port_number = TI_GET_PORT_FROM_CODE(data[0]);
1164         function = TI_GET_FUNC_FROM_CODE(data[0]);
1165
1166         dbg("%s - port_number %d, function %d, data 0x%02X",
1167                                 __func__, port_number, function, data[1]);
1168
1169         if (port_number >= serial->num_ports) {
1170                 dev_err(dev, "%s - bad port number, %d\n",
1171                                                 __func__, port_number);
1172                 goto exit;
1173         }
1174
1175         port = serial->port[port_number];
1176
1177         tport = usb_get_serial_port_data(port);
1178         if (!tport)
1179                 goto exit;
1180
1181         switch (function) {
1182         case TI_CODE_DATA_ERROR:
1183                 dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n",
1184                                         __func__, port_number, data[1]);
1185                 break;
1186
1187         case TI_CODE_MODEM_STATUS:
1188                 msr = data[1];
1189                 dbg("%s - port %d, msr 0x%02X", __func__, port_number, msr);
1190                 ti_handle_new_msr(tport, msr);
1191                 break;
1192
1193         default:
1194                 dev_err(dev, "%s - unknown interrupt code, 0x%02X\n",
1195                                                         __func__, data[1]);
1196                 break;
1197         }
1198
1199 exit:
1200         retval = usb_submit_urb(urb, GFP_ATOMIC);
1201         if (retval)
1202                 dev_err(dev, "%s - resubmit interrupt urb failed, %d\n",
1203                         __func__, retval);
1204 }
1205
1206
1207 static void ti_bulk_in_callback(struct urb *urb)
1208 {
1209         struct ti_port *tport = urb->context;
1210         struct usb_serial_port *port = tport->tp_port;
1211         struct device *dev = &urb->dev->dev;
1212         int status = urb->status;
1213         int retval = 0;
1214
1215         dbg("%s", __func__);
1216
1217         switch (status) {
1218         case 0:
1219                 break;
1220         case -ECONNRESET:
1221         case -ENOENT:
1222         case -ESHUTDOWN:
1223                 dbg("%s - urb shutting down, %d", __func__, status);
1224                 tport->tp_tdev->td_urb_error = 1;
1225                 wake_up_interruptible(&tport->tp_write_wait);
1226                 return;
1227         default:
1228                 dev_err(dev, "%s - nonzero urb status, %d\n",
1229                         __func__, status);
1230                 tport->tp_tdev->td_urb_error = 1;
1231                 wake_up_interruptible(&tport->tp_write_wait);
1232         }
1233
1234         if (status == -EPIPE)
1235                 goto exit;
1236
1237         if (status) {
1238                 dev_err(dev, "%s - stopping read!\n", __func__);
1239                 return;
1240         }
1241
1242         if (port->port.tty && urb->actual_length) {
1243                 usb_serial_debug_data(debug, dev, __func__,
1244                         urb->actual_length, urb->transfer_buffer);
1245
1246                 if (!tport->tp_is_open)
1247                         dbg("%s - port closed, dropping data", __func__);
1248                 else
1249                         ti_recv(&urb->dev->dev, port->port.tty,
1250                                                 urb->transfer_buffer,
1251                                                 urb->actual_length);
1252
1253                 spin_lock(&tport->tp_lock);
1254                 tport->tp_icount.rx += urb->actual_length;
1255                 spin_unlock(&tport->tp_lock);
1256         }
1257
1258 exit:
1259         /* continue to read unless stopping */
1260         spin_lock(&tport->tp_lock);
1261         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1262                 urb->dev = port->serial->dev;
1263                 retval = usb_submit_urb(urb, GFP_ATOMIC);
1264         } else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1265                 tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1266         }
1267         spin_unlock(&tport->tp_lock);
1268         if (retval)
1269                 dev_err(dev, "%s - resubmit read urb failed, %d\n",
1270                         __func__, retval);
1271 }
1272
1273
1274 static void ti_bulk_out_callback(struct urb *urb)
1275 {
1276         struct ti_port *tport = urb->context;
1277         struct usb_serial_port *port = tport->tp_port;
1278         struct device *dev = &urb->dev->dev;
1279         int status = urb->status;
1280
1281         dbg("%s - port %d", __func__, port->number);
1282
1283         tport->tp_write_urb_in_use = 0;
1284
1285         switch (status) {
1286         case 0:
1287                 break;
1288         case -ECONNRESET:
1289         case -ENOENT:
1290         case -ESHUTDOWN:
1291                 dbg("%s - urb shutting down, %d", __func__, status);
1292                 tport->tp_tdev->td_urb_error = 1;
1293                 wake_up_interruptible(&tport->tp_write_wait);
1294                 return;
1295         default:
1296                 dev_err(dev, "%s - nonzero urb status, %d\n",
1297                         __func__, status);
1298                 tport->tp_tdev->td_urb_error = 1;
1299                 wake_up_interruptible(&tport->tp_write_wait);
1300         }
1301
1302         /* send any buffered data */
1303         ti_send(tport);
1304 }
1305
1306
1307 static void ti_recv(struct device *dev, struct tty_struct *tty,
1308         unsigned char *data, int length)
1309 {
1310         int cnt;
1311
1312         do {
1313                 cnt = tty_buffer_request_room(tty, length);
1314                 if (cnt < length) {
1315                         dev_err(dev, "%s - dropping data, %d bytes lost\n",
1316                                                 __func__, length - cnt);
1317                         if (cnt == 0)
1318                                 break;
1319                 }
1320                 tty_insert_flip_string(tty, data, cnt);
1321                 tty_flip_buffer_push(tty);
1322                 data += cnt;
1323                 length -= cnt;
1324         } while (length > 0);
1325
1326 }
1327
1328
1329 static void ti_send(struct ti_port *tport)
1330 {
1331         int count, result;
1332         struct usb_serial_port *port = tport->tp_port;
1333         struct tty_struct *tty = port->port.tty;        /* FIXME */
1334         unsigned long flags;
1335
1336
1337         dbg("%s - port %d", __func__, port->number);
1338
1339         spin_lock_irqsave(&tport->tp_lock, flags);
1340
1341         if (tport->tp_write_urb_in_use) {
1342                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1343                 return;
1344         }
1345
1346         count = ti_buf_get(tport->tp_write_buf,
1347                                 port->write_urb->transfer_buffer,
1348                                 port->bulk_out_size);
1349
1350         if (count == 0) {
1351                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1352                 return;
1353         }
1354
1355         tport->tp_write_urb_in_use = 1;
1356
1357         spin_unlock_irqrestore(&tport->tp_lock, flags);
1358
1359         usb_serial_debug_data(debug, &port->dev, __func__, count,
1360                                         port->write_urb->transfer_buffer);
1361
1362         usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1363                            usb_sndbulkpipe(port->serial->dev,
1364                                             port->bulk_out_endpointAddress),
1365                            port->write_urb->transfer_buffer, count,
1366                            ti_bulk_out_callback, tport);
1367
1368         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1369         if (result) {
1370                 dev_err(&port->dev, "%s - submit write urb failed, %d\n",
1371                                                         __func__, result);
1372                 tport->tp_write_urb_in_use = 0;
1373                 /* TODO: reschedule ti_send */
1374         } else {
1375                 spin_lock_irqsave(&tport->tp_lock, flags);
1376                 tport->tp_icount.tx += count;
1377                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1378         }
1379
1380         /* more room in the buffer for new writes, wakeup */
1381         if (tty)
1382                 tty_wakeup(tty);
1383         wake_up_interruptible(&tport->tp_write_wait);
1384 }
1385
1386
1387 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1388 {
1389         unsigned long flags;
1390         int status;
1391
1392         status = ti_write_byte(tport->tp_tdev,
1393                 tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1394                 TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1395
1396         spin_lock_irqsave(&tport->tp_lock, flags);
1397         if (!status)
1398                 tport->tp_shadow_mcr = mcr;
1399         spin_unlock_irqrestore(&tport->tp_lock, flags);
1400
1401         return status;
1402 }
1403
1404
1405 static int ti_get_lsr(struct ti_port *tport)
1406 {
1407         int size, status;
1408         struct ti_device *tdev = tport->tp_tdev;
1409         struct usb_serial_port *port = tport->tp_port;
1410         int port_number = port->number - port->serial->minor;
1411         struct ti_port_status *data;
1412
1413         dbg("%s - port %d", __func__, port->number);
1414
1415         size = sizeof(struct ti_port_status);
1416         data = kmalloc(size, GFP_KERNEL);
1417         if (!data) {
1418                 dev_err(&port->dev, "%s - out of memory\n", __func__);
1419                 return -ENOMEM;
1420         }
1421
1422         status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1423                 (__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1424         if (status) {
1425                 dev_err(&port->dev,
1426                         "%s - get port status command failed, %d\n",
1427                                                         __func__, status);
1428                 goto free_data;
1429         }
1430
1431         dbg("%s - lsr 0x%02X", __func__, data->bLSR);
1432
1433         tport->tp_lsr = data->bLSR;
1434
1435 free_data:
1436         kfree(data);
1437         return status;
1438 }
1439
1440
1441 static int ti_get_serial_info(struct ti_port *tport,
1442         struct serial_struct __user *ret_arg)
1443 {
1444         struct usb_serial_port *port = tport->tp_port;
1445         struct serial_struct ret_serial;
1446
1447         if (!ret_arg)
1448                 return -EFAULT;
1449
1450         memset(&ret_serial, 0, sizeof(ret_serial));
1451
1452         ret_serial.type = PORT_16550A;
1453         ret_serial.line = port->serial->minor;
1454         ret_serial.port = port->number - port->serial->minor;
1455         ret_serial.flags = tport->tp_flags;
1456         ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1457         ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1458         ret_serial.closing_wait = tport->tp_closing_wait;
1459
1460         if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1461                 return -EFAULT;
1462
1463         return 0;
1464 }
1465
1466
1467 static int ti_set_serial_info(struct ti_port *tport,
1468         struct serial_struct __user *new_arg)
1469 {
1470         struct usb_serial_port *port = tport->tp_port;
1471         struct serial_struct new_serial;
1472
1473         if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1474                 return -EFAULT;
1475
1476         tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1477         /* FIXME */
1478         if (port->port.tty)
1479                 port->port.tty->low_latency =
1480                         (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
1481         tport->tp_closing_wait = new_serial.closing_wait;
1482
1483         return 0;
1484 }
1485
1486
1487 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
1488 {
1489         struct async_icount *icount;
1490         struct tty_struct *tty;
1491         unsigned long flags;
1492
1493         dbg("%s - msr 0x%02X", __func__, msr);
1494
1495         if (msr & TI_MSR_DELTA_MASK) {
1496                 spin_lock_irqsave(&tport->tp_lock, flags);
1497                 icount = &tport->tp_icount;
1498                 if (msr & TI_MSR_DELTA_CTS)
1499                         icount->cts++;
1500                 if (msr & TI_MSR_DELTA_DSR)
1501                         icount->dsr++;
1502                 if (msr & TI_MSR_DELTA_CD)
1503                         icount->dcd++;
1504                 if (msr & TI_MSR_DELTA_RI)
1505                         icount->rng++;
1506                 wake_up_interruptible(&tport->tp_msr_wait);
1507                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1508         }
1509
1510         tport->tp_msr = msr & TI_MSR_MASK;
1511
1512         /* handle CTS flow control */
1513         tty = tport->tp_port->port.tty;
1514         if (tty && C_CRTSCTS(tty)) {
1515                 if (msr & TI_MSR_CTS) {
1516                         tty->hw_stopped = 0;
1517                         tty_wakeup(tty);
1518                 } else {
1519                         tty->hw_stopped = 1;
1520                 }
1521         }
1522 }
1523
1524
1525 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1526 {
1527         struct ti_device *tdev = tport->tp_tdev;
1528         struct usb_serial_port *port = tport->tp_port;
1529         wait_queue_t wait;
1530
1531         dbg("%s - port %d", __func__, port->number);
1532
1533         spin_lock_irq(&tport->tp_lock);
1534
1535         /* wait for data to drain from the buffer */
1536         tdev->td_urb_error = 0;
1537         init_waitqueue_entry(&wait, current);
1538         add_wait_queue(&tport->tp_write_wait, &wait);
1539         for (;;) {
1540                 set_current_state(TASK_INTERRUPTIBLE);
1541                 if (ti_buf_data_avail(tport->tp_write_buf) == 0
1542                 || timeout == 0 || signal_pending(current)
1543                 || tdev->td_urb_error
1544                 || port->serial->disconnected)  /* disconnect */
1545                         break;
1546                 spin_unlock_irq(&tport->tp_lock);
1547                 timeout = schedule_timeout(timeout);
1548                 spin_lock_irq(&tport->tp_lock);
1549         }
1550         set_current_state(TASK_RUNNING);
1551         remove_wait_queue(&tport->tp_write_wait, &wait);
1552
1553         /* flush any remaining data in the buffer */
1554         if (flush)
1555                 ti_buf_clear(tport->tp_write_buf);
1556
1557         spin_unlock_irq(&tport->tp_lock);
1558
1559         mutex_lock(&port->serial->disc_mutex);
1560         /* wait for data to drain from the device */
1561         /* wait for empty tx register, plus 20 ms */
1562         timeout += jiffies;
1563         tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1564         while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1565         && !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1566         && !port->serial->disconnected) {
1567                 if (ti_get_lsr(tport))
1568                         break;
1569                 mutex_unlock(&port->serial->disc_mutex);
1570                 msleep_interruptible(20);
1571                 mutex_lock(&port->serial->disc_mutex);
1572         }
1573         mutex_unlock(&port->serial->disc_mutex);
1574 }
1575
1576
1577 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1578 {
1579         unsigned long flags;
1580
1581         spin_lock_irqsave(&tport->tp_lock, flags);
1582
1583         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1584                 tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1585
1586         spin_unlock_irqrestore(&tport->tp_lock, flags);
1587 }
1588
1589
1590 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1591 {
1592         struct urb *urb;
1593         int status = 0;
1594         unsigned long flags;
1595
1596         spin_lock_irqsave(&tport->tp_lock, flags);
1597
1598         if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1599                 tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1600                 urb = tport->tp_port->read_urb;
1601                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1602                 urb->complete = ti_bulk_in_callback;
1603                 urb->context = tport;
1604                 urb->dev = tport->tp_port->serial->dev;
1605                 status = usb_submit_urb(urb, GFP_KERNEL);
1606         } else  {
1607                 tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1608                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1609         }
1610
1611         return status;
1612 }
1613
1614
1615 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1616         __u16 moduleid, __u16 value, __u8 *data, int size)
1617 {
1618         int status;
1619
1620         status = usb_control_msg(tdev->td_serial->dev,
1621                 usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1622                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1623                 value, moduleid, data, size, 1000);
1624
1625         if (status == size)
1626                 status = 0;
1627
1628         if (status > 0)
1629                 status = -ECOMM;
1630
1631         return status;
1632 }
1633
1634
1635 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1636         __u16 moduleid, __u16 value, __u8 *data, int size)
1637 {
1638         int status;
1639
1640         status = usb_control_msg(tdev->td_serial->dev,
1641                 usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1642                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1643                 value, moduleid, data, size, 1000);
1644
1645         if (status == size)
1646                 status = 0;
1647
1648         if (status > 0)
1649                 status = -ECOMM;
1650
1651         return status;
1652 }
1653
1654
1655 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1656         __u8 mask, __u8 byte)
1657 {
1658         int status;
1659         unsigned int size;
1660         struct ti_write_data_bytes *data;
1661         struct device *dev = &tdev->td_serial->dev->dev;
1662
1663         dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X",
1664                                         __func__, addr, mask, byte);
1665
1666         size = sizeof(struct ti_write_data_bytes) + 2;
1667         data = kmalloc(size, GFP_KERNEL);
1668         if (!data) {
1669                 dev_err(dev, "%s - out of memory\n", __func__);
1670                 return -ENOMEM;
1671         }
1672
1673         data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1674         data->bDataType = TI_RW_DATA_BYTE;
1675         data->bDataCounter = 1;
1676         data->wBaseAddrHi = cpu_to_be16(addr>>16);
1677         data->wBaseAddrLo = cpu_to_be16(addr);
1678         data->bData[0] = mask;
1679         data->bData[1] = byte;
1680
1681         status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1682                 (__u8 *)data, size);
1683
1684         if (status < 0)
1685                 dev_err(dev, "%s - failed, %d\n", __func__, status);
1686
1687         kfree(data);
1688
1689         return status;
1690 }
1691
1692 static int ti_do_download(struct usb_device *dev, int pipe,
1693                                                 u8 *buffer, int size)
1694 {
1695         int pos;
1696         u8 cs = 0;
1697         int done;
1698         struct ti_firmware_header *header;
1699         int status;
1700         int len;
1701
1702         for (pos = sizeof(struct ti_firmware_header); pos < size; pos++)
1703                 cs = (__u8)(cs + buffer[pos]);
1704
1705         header = (struct ti_firmware_header *)buffer;
1706         header->wLength = cpu_to_le16((__u16)(size
1707                                         - sizeof(struct ti_firmware_header)));
1708         header->bCheckSum = cs;
1709
1710         dbg("%s - downloading firmware", __func__);
1711         for (pos = 0; pos < size; pos += done) {
1712                 len = min(size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1713                 status = usb_bulk_msg(dev, pipe, buffer + pos, len,
1714                                                                 &done, 1000);
1715                 if (status)
1716                         break;
1717         }
1718         return status;
1719 }
1720
1721 static int ti_download_firmware(struct ti_device *tdev, int type)
1722 {
1723         int status = -ENOMEM;
1724         int buffer_size;
1725         __u8 *buffer;
1726         struct usb_device *dev = tdev->td_serial->dev;
1727         unsigned int pipe = usb_sndbulkpipe(dev,
1728                 tdev->td_serial->port[0]->bulk_out_endpointAddress);
1729         const struct firmware *fw_p;
1730         char buf[32];
1731         sprintf(buf, "ti_usb-%d.bin", type);
1732
1733         if (request_firmware(&fw_p, buf, &dev->dev)) {
1734                 dev_err(&dev->dev, "%s - firmware not found\n", __func__);
1735                 return -ENOENT;
1736         }
1737         if (fw_p->size > TI_FIRMWARE_BUF_SIZE) {
1738                 dev_err(&dev->dev, "%s - firmware too large\n", __func__);
1739                 return -ENOENT;
1740         }
1741
1742         buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1743         buffer = kmalloc(buffer_size, GFP_KERNEL);
1744         if (buffer) {
1745                 memcpy(buffer, fw_p->data, fw_p->size);
1746                 memset(buffer + fw_p->size, 0xff, buffer_size - fw_p->size);
1747                 ti_do_download(dev, pipe, buffer, fw_p->size);
1748                 kfree(buffer);
1749         }
1750         release_firmware(fw_p);
1751         if (status) {
1752                 dev_err(&dev->dev, "%s - error downloading firmware, %d\n",
1753                                                         __func__, status);
1754                 return status;
1755         }
1756
1757         dbg("%s - download successful", __func__);
1758
1759         return 0;
1760 }
1761
1762
1763 /* Circular Buffer Functions */
1764
1765 /*
1766  * ti_buf_alloc
1767  *
1768  * Allocate a circular buffer and all associated memory.
1769  */
1770
1771 static struct circ_buf *ti_buf_alloc(void)
1772 {
1773         struct circ_buf *cb;
1774
1775         cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1776         if (cb == NULL)
1777                 return NULL;
1778
1779         cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1780         if (cb->buf == NULL) {
1781                 kfree(cb);
1782                 return NULL;
1783         }
1784
1785         ti_buf_clear(cb);
1786
1787         return cb;
1788 }
1789
1790
1791 /*
1792  * ti_buf_free
1793  *
1794  * Free the buffer and all associated memory.
1795  */
1796
1797 static void ti_buf_free(struct circ_buf *cb)
1798 {
1799         kfree(cb->buf);
1800         kfree(cb);
1801 }
1802
1803
1804 /*
1805  * ti_buf_clear
1806  *
1807  * Clear out all data in the circular buffer.
1808  */
1809
1810 static void ti_buf_clear(struct circ_buf *cb)
1811 {
1812         cb->head = cb->tail = 0;
1813 }
1814
1815
1816 /*
1817  * ti_buf_data_avail
1818  *
1819  * Return the number of bytes of data available in the circular
1820  * buffer.
1821  */
1822
1823 static int ti_buf_data_avail(struct circ_buf *cb)
1824 {
1825         return CIRC_CNT(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1826 }
1827
1828
1829 /*
1830  * ti_buf_space_avail
1831  *
1832  * Return the number of bytes of space available in the circular
1833  * buffer.
1834  */
1835
1836 static int ti_buf_space_avail(struct circ_buf *cb)
1837 {
1838         return CIRC_SPACE(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1839 }
1840
1841
1842 /*
1843  * ti_buf_put
1844  *
1845  * Copy data data from a user buffer and put it into the circular buffer.
1846  * Restrict to the amount of space available.
1847  *
1848  * Return the number of bytes copied.
1849  */
1850
1851 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1852 {
1853         int c, ret = 0;
1854
1855         while (1) {
1856                 c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1857                 if (count < c)
1858                         c = count;
1859                 if (c <= 0)
1860                         break;
1861                 memcpy(cb->buf + cb->head, buf, c);
1862                 cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1863                 buf += c;
1864                 count -= c;
1865                 ret += c;
1866         }
1867
1868         return ret;
1869 }
1870
1871
1872 /*
1873  * ti_buf_get
1874  *
1875  * Get data from the circular buffer and copy to the given buffer.
1876  * Restrict to the amount of data available.
1877  *
1878  * Return the number of bytes copied.
1879  */
1880
1881 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1882 {
1883         int c, ret = 0;
1884
1885         while (1) {
1886                 c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1887                 if (count < c)
1888                         c = count;
1889                 if (c <= 0)
1890                         break;
1891                 memcpy(buf, cb->buf + cb->tail, c);
1892                 cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1893                 buf += c;
1894                 count -= c;
1895                 ret += c;
1896         }
1897
1898         return ret;
1899 }