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
  89 #include "ti_usb_3410_5052.h"
  90
  91 /* Defines */
  92
  93 #define TI_DRIVER_VERSION       "v0.9"
  94 #define TI_DRIVER_AUTHOR        "Al Borchers <alborchers@steinerpoint.com>"
  95 #define TI_DRIVER_DESC          "TI USB 3410/5052 Serial Driver"
  96
  97 #define TI_FIRMWARE_BUF_SIZE    16284
  98
  99 #define TI_WRITE_BUF_SIZE       1024
 100
 101 #define TI_TRANSFER_TIMEOUT     2
 102
 103 #define TI_DEFAULT_LOW_LATENCY  0
 104 #define TI_DEFAULT_CLOSING_WAIT 4000            /* in .01 secs */
 105
 106 /* supported setserial flags */
 107 #define TI_SET_SERIAL_FLAGS     (ASYNC_LOW_LATENCY)
 108
 109 /* read urb states */
 110 #define TI_READ_URB_RUNNING     0
 111 #define TI_READ_URB_STOPPING    1
 112 #define TI_READ_URB_STOPPED     2
 113
 114 #define TI_EXTRA_VID_PID_COUNT  5
 115
 116
 117 /* Structures */
 118
 119 struct ti_port {
 120         int                     tp_is_open;
 121         __u8                    tp_msr;
 122         __u8                    tp_lsr;
 123         __u8                    tp_shadow_mcr;
 124         __u8                    tp_uart_mode;   /* 232 or 485 modes */
 125         unsigned int            tp_uart_base_addr;
 126         int                     tp_flags;
 127         int                     tp_closing_wait;/* in .01 secs */
 128         struct async_icount     tp_icount;
 129         wait_queue_head_t       tp_msr_wait;    /* wait for msr change */
 130         wait_queue_head_t       tp_write_wait;
 131         struct ti_device        *tp_tdev;
 132         struct usb_serial_port  *tp_port;
 133         spinlock_t              tp_lock;
 134         int                     tp_read_urb_state;
 135         int                     tp_write_urb_in_use;
 136         struct circ_buf         *tp_write_buf;
 137 };
 138
 139 struct ti_device {
 140         struct mutex            td_open_close_lock;
 141         int                     td_open_port_count;
 142         struct usb_serial       *td_serial;
 143         int                     td_is_3410;
 144         int                     td_urb_error;
 145 };
 146
 147
 148 /* Function Declarations */
 149
 150 static int ti_startup(struct usb_serial *serial);
 151 static void ti_shutdown(struct usb_serial *serial);
 152 static int ti_open(struct tty_struct *tty, struct usb_serial_port *port,
 153                 struct file *file);
 154 static void ti_close(struct tty_struct *tty, struct usb_serial_port *port,
 155                 struct file *file);
 156 static int ti_write(struct tty_struct *tty, struct usb_serial_port *port,
 157                 const unsigned char *data, int count);
 158 static int ti_write_room(struct tty_struct *tty);
 159 static int ti_chars_in_buffer(struct tty_struct *tty);
 160 static void ti_throttle(struct tty_struct *tty);
 161 static void ti_unthrottle(struct tty_struct *tty);
 162 static int ti_ioctl(struct tty_struct *tty, struct file *file,
 163                 unsigned int cmd, unsigned long arg);
 164 static void ti_set_termios(struct tty_struct *tty,
 165                 struct usb_serial_port *port, struct ktermios *old_termios);
 166 static int ti_tiocmget(struct tty_struct *tty, struct file *file);
 167 static int ti_tiocmset(struct tty_struct *tty, struct file *file,
 168                 unsigned int set, unsigned int clear);
 169 static void ti_break(struct tty_struct *tty, int break_state);
 170 static void ti_interrupt_callback(struct urb *urb);
 171 static void ti_bulk_in_callback(struct urb *urb);
 172 static void ti_bulk_out_callback(struct urb *urb);
 173
 174 static void ti_recv(struct device *dev, struct tty_struct *tty,
 175         unsigned char *data, int length);
 176 static void ti_send(struct ti_port *tport);
 177 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr);
 178 static int ti_get_lsr(struct ti_port *tport);
 179 static int ti_get_serial_info(struct ti_port *tport,
 180         struct serial_struct __user *ret_arg);
 181 static int ti_set_serial_info(struct tty_struct *tty, struct ti_port *tport,
 182         struct serial_struct __user *new_arg);
 183 static void ti_handle_new_msr(struct ti_port *tport, __u8 msr);
 184
 185 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush);
 186
 187 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty);
 188 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty);
 189
 190 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
 191         __u16 moduleid, __u16 value, __u8 *data, int size);
 192 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
 193         __u16 moduleid, __u16 value, __u8 *data, int size);
 194
 195 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
 196         __u8 mask, __u8 byte);
 197
 198 static int ti_download_firmware(struct ti_device *tdev, int type);
 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_ports              = 1,
 268         .attach                 = ti_startup,
 269         .shutdown               = ti_shutdown,
 270         .open                   = ti_open,
 271         .close                  = ti_close,
 272         .write                  = ti_write,
 273         .write_room             = ti_write_room,
 274         .chars_in_buffer        = ti_chars_in_buffer,
 275         .throttle               = ti_throttle,
 276         .unthrottle             = ti_unthrottle,
 277         .ioctl                  = ti_ioctl,
 278         .set_termios            = ti_set_termios,
 279         .tiocmget               = ti_tiocmget,
 280         .tiocmset               = ti_tiocmset,
 281         .break_ctl              = ti_break,
 282         .read_int_callback      = ti_interrupt_callback,
 283         .read_bulk_callback     = ti_bulk_in_callback,
 284         .write_bulk_callback    = ti_bulk_out_callback,
 285 };
 286
 287 static struct usb_serial_driver ti_2port_device = {
 288         .driver = {
 289                 .owner          = THIS_MODULE,
 290                 .name           = "ti_usb_3410_5052_2",
 291         },
 292         .description            = "TI USB 5052 2 port adapter",
 293         .usb_driver             = &ti_usb_driver,
 294         .id_table               = ti_id_table_5052,
 295         .num_ports              = 2,
 296         .attach                 = ti_startup,
 297         .shutdown               = ti_shutdown,
 298         .open                   = ti_open,
 299         .close                  = ti_close,
 300         .write                  = ti_write,
 301         .write_room             = ti_write_room,
 302         .chars_in_buffer        = ti_chars_in_buffer,
 303         .throttle               = ti_throttle,
 304         .unthrottle             = ti_unthrottle,
 305         .ioctl                  = ti_ioctl,
 306         .set_termios            = ti_set_termios,
 307         .tiocmget               = ti_tiocmget,
 308         .tiocmset               = ti_tiocmset,
 309         .break_ctl              = ti_break,
 310         .read_int_callback      = ti_interrupt_callback,
 311         .read_bulk_callback     = ti_bulk_in_callback,
 312         .write_bulk_callback    = ti_bulk_out_callback,
 313 };
 314
 315
 316 /* Module */
 317
 318 MODULE_AUTHOR(TI_DRIVER_AUTHOR);
 319 MODULE_DESCRIPTION(TI_DRIVER_DESC);
 320 MODULE_VERSION(TI_DRIVER_VERSION);
 321 MODULE_LICENSE("GPL");
 322
 323 MODULE_FIRMWARE("ti_3410.fw");
 324 MODULE_FIRMWARE("ti_5052.fw");
 325
 326 module_param(debug, bool, S_IRUGO | S_IWUSR);
 327 MODULE_PARM_DESC(debug, "Enable debugging, 0=no, 1=yes");
 328
 329 module_param(low_latency, bool, S_IRUGO | S_IWUSR);
 330 MODULE_PARM_DESC(low_latency,
 331                 "TTY low_latency flag, 0=off, 1=on, default is off");
 332
 333 module_param(closing_wait, int, S_IRUGO | S_IWUSR);
 334 MODULE_PARM_DESC(closing_wait,
 335     "Maximum wait for data to drain in close, in .01 secs, default is 4000");
 336
 337 module_param_array(vendor_3410, ushort, &vendor_3410_count, S_IRUGO);
 338 MODULE_PARM_DESC(vendor_3410,
 339                 "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,
 342                 "Product ids for 3410 based devices, 1-5 short integers");
 343 module_param_array(vendor_5052, ushort, &vendor_5052_count, S_IRUGO);
 344 MODULE_PARM_DESC(vendor_5052,
 345                 "Vendor ids for 5052 based devices, 1-5 short integers");
 346 module_param_array(product_5052, ushort, &product_5052_count, S_IRUGO);
 347 MODULE_PARM_DESC(product_5052,
 348                 "Product ids for 5052 based devices, 1-5 short integers");
 349
 350 MODULE_DEVICE_TABLE(usb, ti_id_table_combined);
 351
 352
 353 /* Functions */
 354
 355 static int __init ti_init(void)
 356 {
 357         int i, j;
 358         int ret;
 359
 360         /* insert extra vendor and product ids */
 361         j = ARRAY_SIZE(ti_id_table_3410) - TI_EXTRA_VID_PID_COUNT - 1;
 362         for (i = 0; i < min(vendor_3410_count, product_3410_count); i++, j++) {
 363                 ti_id_table_3410[j].idVendor = vendor_3410[i];
 364                 ti_id_table_3410[j].idProduct = product_3410[i];
 365                 ti_id_table_3410[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 366         }
 367         j = ARRAY_SIZE(ti_id_table_5052) - TI_EXTRA_VID_PID_COUNT - 1;
 368         for (i = 0; i < min(vendor_5052_count, product_5052_count); i++, j++) {
 369                 ti_id_table_5052[j].idVendor = vendor_5052[i];
 370                 ti_id_table_5052[j].idProduct = product_5052[i];
 371                 ti_id_table_5052[j].match_flags = USB_DEVICE_ID_MATCH_DEVICE;
 372         }
 373
 374         ret = usb_serial_register(&ti_1port_device);
 375         if (ret)
 376                 goto failed_1port;
 377         ret = usb_serial_register(&ti_2port_device);
 378         if (ret)
 379                 goto failed_2port;
 380
 381         ret = usb_register(&ti_usb_driver);
 382         if (ret)
 383                 goto failed_usb;
 384
 385         info(TI_DRIVER_DESC " " TI_DRIVER_VERSION);
 386
 387         return 0;
 388
 389 failed_usb:
 390         usb_serial_deregister(&ti_2port_device);
 391 failed_2port:
 392         usb_serial_deregister(&ti_1port_device);
 393 failed_1port:
 394         return ret;
 395 }
 396
 397
 398 static void __exit ti_exit(void)
 399 {
 400         usb_serial_deregister(&ti_1port_device);
 401         usb_serial_deregister(&ti_2port_device);
 402         usb_deregister(&ti_usb_driver);
 403 }
 404
 405
 406 module_init(ti_init);
 407 module_exit(ti_exit);
 408
 409
 410 static int ti_startup(struct usb_serial *serial)
 411 {
 412         struct ti_device *tdev;
 413         struct ti_port *tport;
 414         struct usb_device *dev = serial->dev;
 415         int status;
 416         int i;
 417
 418
 419         dbg("%s - product 0x%4X, num configurations %d, configuration value %d",
 420             __func__, le16_to_cpu(dev->descriptor.idProduct),
 421             dev->descriptor.bNumConfigurations,
 422             dev->actconfig->desc.bConfigurationValue);
 423
 424         /* create device structure */
 425         tdev = kzalloc(sizeof(struct ti_device), GFP_KERNEL);
 426         if (tdev == NULL) {
 427                 dev_err(&dev->dev, "%s - out of memory\n", __func__);
 428                 return -ENOMEM;
 429         }
 430         mutex_init(&tdev->td_open_close_lock);
 431         tdev->td_serial = serial;
 432         usb_set_serial_data(serial, tdev);
 433
 434         /* determine device type */
 435         if (usb_match_id(serial->interface, ti_id_table_3410))
 436                 tdev->td_is_3410 = 1;
 437         dbg("%s - device type is %s", __func__,
 438                                 tdev->td_is_3410 ? "3410" : "5052");
 439
 440         /* if we have only 1 configuration, download firmware */
 441         if (dev->descriptor.bNumConfigurations == 1) {
 442                 if (tdev->td_is_3410)
 443                         status = ti_download_firmware(tdev, 3410);
 444                 else
 445                         status = ti_download_firmware(tdev, 5052);
 446                 if (status)
 447                         goto free_tdev;
 448
 449                 /* 3410 must be reset, 5052 resets itself */
 450                 if (tdev->td_is_3410) {
 451                         msleep_interruptible(100);
 452                         usb_reset_device(dev);
 453                 }
 454
 455                 status = -ENODEV;
 456                 goto free_tdev;
 457         }
 458
 459         /* the second configuration must be set (in sysfs by hotplug script) */
 460         if (dev->actconfig->desc.bConfigurationValue == TI_BOOT_CONFIG) {
 461                 status = -ENODEV;
 462                 goto free_tdev;
 463         }
 464
 465         /* set up port structures */
 466         for (i = 0; i < serial->num_ports; ++i) {
 467                 tport = kzalloc(sizeof(struct ti_port), GFP_KERNEL);
 468                 if (tport == NULL) {
 469                         dev_err(&dev->dev, "%s - out of memory\n", __func__);
 470                         status = -ENOMEM;
 471                         goto free_tports;
 472                 }
 473                 spin_lock_init(&tport->tp_lock);
 474                 tport->tp_uart_base_addr = (i == 0 ?
 475                                 TI_UART1_BASE_ADDR : TI_UART2_BASE_ADDR);
 476                 tport->tp_flags = low_latency ? ASYNC_LOW_LATENCY : 0;
 477                 tport->tp_closing_wait = closing_wait;
 478                 init_waitqueue_head(&tport->tp_msr_wait);
 479                 init_waitqueue_head(&tport->tp_write_wait);
 480                 tport->tp_write_buf = ti_buf_alloc();
 481                 if (tport->tp_write_buf == NULL) {
 482                         dev_err(&dev->dev, "%s - out of memory\n", __func__);
 483                         kfree(tport);
 484                         status = -ENOMEM;
 485                         goto free_tports;
 486                 }
 487                 tport->tp_port = serial->port[i];
 488                 tport->tp_tdev = tdev;
 489                 usb_set_serial_port_data(serial->port[i], tport);
 490                 tport->tp_uart_mode = 0;        /* default is RS232 */
 491         }
 492
 493         return 0;
 494
 495 free_tports:
 496         for (--i; i >= 0; --i) {
 497                 tport = usb_get_serial_port_data(serial->port[i]);
 498                 ti_buf_free(tport->tp_write_buf);
 499                 kfree(tport);
 500                 usb_set_serial_port_data(serial->port[i], NULL);
 501         }
 502 free_tdev:
 503         kfree(tdev);
 504         usb_set_serial_data(serial, NULL);
 505         return status;
 506 }
 507
 508
 509 static void ti_shutdown(struct usb_serial *serial)
 510 {
 511         int i;
 512         struct ti_device *tdev = usb_get_serial_data(serial);
 513         struct ti_port *tport;
 514
 515         dbg("%s", __func__);
 516
 517         for (i = 0; i < serial->num_ports; ++i) {
 518                 tport = usb_get_serial_port_data(serial->port[i]);
 519                 if (tport) {
 520                         ti_buf_free(tport->tp_write_buf);
 521                         kfree(tport);
 522                         usb_set_serial_port_data(serial->port[i], NULL);
 523                 }
 524         }
 525
 526         kfree(tdev);
 527         usb_set_serial_data(serial, NULL);
 528 }
 529
 530
 531 static int ti_open(struct tty_struct *tty,
 532                         struct usb_serial_port *port, struct file *file)
 533 {
 534         struct ti_port *tport = usb_get_serial_port_data(port);
 535         struct ti_device *tdev;
 536         struct usb_device *dev;
 537         struct urb *urb;
 538         int port_number;
 539         int status;
 540         __u16 open_settings = (__u8)(TI_PIPE_MODE_CONTINOUS |
 541                              TI_PIPE_TIMEOUT_ENABLE |
 542                              (TI_TRANSFER_TIMEOUT << 2));
 543
 544         dbg("%s - port %d", __func__, port->number);
 545
 546         if (tport == NULL)
 547                 return -ENODEV;
 548
 549         dev = port->serial->dev;
 550         tdev = tport->tp_tdev;
 551
 552         /* only one open on any port on a device at a time */
 553         if (mutex_lock_interruptible(&tdev->td_open_close_lock))
 554                 return -ERESTARTSYS;
 555
 556         if (tty)
 557                 tty->low_latency =
 558                                 (tport->tp_flags & ASYNC_LOW_LATENCY) ? 1 : 0;
 559
 560         port_number = port->number - port->serial->minor;
 561
 562         memset(&(tport->tp_icount), 0x00, sizeof(tport->tp_icount));
 563
 564         tport->tp_msr = 0;
 565         tport->tp_shadow_mcr |= (TI_MCR_RTS | TI_MCR_DTR);
 566
 567         /* start interrupt urb the first time a port is opened on this device */
 568         if (tdev->td_open_port_count == 0) {
 569                 dbg("%s - start interrupt in urb", __func__);
 570                 urb = tdev->td_serial->port[0]->interrupt_in_urb;
 571                 if (!urb) {
 572                         dev_err(&port->dev, "%s - no interrupt urb\n",
 573                                                                 __func__);
 574                         status = -EINVAL;
 575                         goto release_lock;
 576                 }
 577                 urb->complete = ti_interrupt_callback;
 578                 urb->context = tdev;
 579                 urb->dev = dev;
 580                 status = usb_submit_urb(urb, GFP_KERNEL);
 581                 if (status) {
 582                         dev_err(&port->dev,
 583                                 "%s - submit interrupt urb failed, %d\n",
 584                                         __func__, status);
 585                         goto release_lock;
 586                 }
 587         }
 588
 589         if (tty)
 590                 ti_set_termios(tty, port, tty->termios);
 591
 592         dbg("%s - sending TI_OPEN_PORT", __func__);
 593         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 594                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 595         if (status) {
 596                 dev_err(&port->dev, "%s - cannot send open command, %d\n",
 597                                                         __func__, status);
 598                 goto unlink_int_urb;
 599         }
 600
 601         dbg("%s - sending TI_START_PORT", __func__);
 602         status = ti_command_out_sync(tdev, TI_START_PORT,
 603                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 604         if (status) {
 605                 dev_err(&port->dev, "%s - cannot send start command, %d\n",
 606                                                         __func__, status);
 607                 goto unlink_int_urb;
 608         }
 609
 610         dbg("%s - sending TI_PURGE_PORT", __func__);
 611         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 612                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_INPUT, NULL, 0);
 613         if (status) {
 614                 dev_err(&port->dev, "%s - cannot clear input buffers, %d\n",
 615                                                         __func__, status);
 616                 goto unlink_int_urb;
 617         }
 618         status = ti_command_out_sync(tdev, TI_PURGE_PORT,
 619                 (__u8)(TI_UART1_PORT + port_number), TI_PURGE_OUTPUT, NULL, 0);
 620         if (status) {
 621                 dev_err(&port->dev, "%s - cannot clear output buffers, %d\n",
 622                                                         __func__, status);
 623                 goto unlink_int_urb;
 624         }
 625
 626         /* reset the data toggle on the bulk endpoints to work around bug in
 627          * host controllers where things get out of sync some times */
 628         usb_clear_halt(dev, port->write_urb->pipe);
 629         usb_clear_halt(dev, port->read_urb->pipe);
 630
 631         if (tty)
 632                 ti_set_termios(tty, port, tty->termios);
 633
 634         dbg("%s - sending TI_OPEN_PORT (2)", __func__);
 635         status = ti_command_out_sync(tdev, TI_OPEN_PORT,
 636                 (__u8)(TI_UART1_PORT + port_number), open_settings, NULL, 0);
 637         if (status) {
 638                 dev_err(&port->dev, "%s - cannot send open command (2), %d\n",
 639                                                         __func__, status);
 640                 goto unlink_int_urb;
 641         }
 642
 643         dbg("%s - sending TI_START_PORT (2)", __func__);
 644         status = ti_command_out_sync(tdev, TI_START_PORT,
 645                 (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 646         if (status) {
 647                 dev_err(&port->dev, "%s - cannot send start command (2), %d\n",
 648                                                         __func__, status);
 649                 goto unlink_int_urb;
 650         }
 651
 652         /* start read urb */
 653         dbg("%s - start read urb", __func__);
 654         urb = port->read_urb;
 655         if (!urb) {
 656                 dev_err(&port->dev, "%s - no read urb\n", __func__);
 657                 status = -EINVAL;
 658                 goto unlink_int_urb;
 659         }
 660         tport->tp_read_urb_state = TI_READ_URB_RUNNING;
 661         urb->complete = ti_bulk_in_callback;
 662         urb->context = tport;
 663         urb->dev = dev;
 664         status = usb_submit_urb(urb, GFP_KERNEL);
 665         if (status) {
 666                 dev_err(&port->dev, "%s - submit read urb failed, %d\n",
 667                                                         __func__, status);
 668                 goto unlink_int_urb;
 669         }
 670
 671         tport->tp_is_open = 1;
 672         ++tdev->td_open_port_count;
 673
 674         goto release_lock;
 675
 676 unlink_int_urb:
 677         if (tdev->td_open_port_count == 0)
 678                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 679 release_lock:
 680         mutex_unlock(&tdev->td_open_close_lock);
 681         dbg("%s - exit %d", __func__, status);
 682         return status;
 683 }
 684
 685
 686 static void ti_close(struct tty_struct *tty, struct usb_serial_port *port,
 687                                                         struct file *file)
 688 {
 689         struct ti_device *tdev;
 690         struct ti_port *tport;
 691         int port_number;
 692         int status;
 693         int do_unlock;
 694
 695         dbg("%s - port %d", __func__, port->number);
 696
 697         tdev = usb_get_serial_data(port->serial);
 698         tport = usb_get_serial_port_data(port);
 699         if (tdev == NULL || tport == NULL)
 700                 return;
 701
 702         tport->tp_is_open = 0;
 703
 704         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 1);
 705
 706         usb_kill_urb(port->read_urb);
 707         usb_kill_urb(port->write_urb);
 708         tport->tp_write_urb_in_use = 0;
 709
 710         port_number = port->number - port->serial->minor;
 711
 712         dbg("%s - sending TI_CLOSE_PORT", __func__);
 713         status = ti_command_out_sync(tdev, TI_CLOSE_PORT,
 714                      (__u8)(TI_UART1_PORT + port_number), 0, NULL, 0);
 715         if (status)
 716                 dev_err(&port->dev,
 717                         "%s - cannot send close port command, %d\n"
 718                                                         , __func__, status);
 719
 720         /* if mutex_lock is interrupted, continue anyway */
 721         do_unlock = !mutex_lock_interruptible(&tdev->td_open_close_lock);
 722         --tport->tp_tdev->td_open_port_count;
 723         if (tport->tp_tdev->td_open_port_count <= 0) {
 724                 /* last port is closed, shut down interrupt urb */
 725                 usb_kill_urb(port->serial->port[0]->interrupt_in_urb);
 726                 tport->tp_tdev->td_open_port_count = 0;
 727         }
 728         if (do_unlock)
 729                 mutex_unlock(&tdev->td_open_close_lock);
 730
 731         dbg("%s - exit", __func__);
 732 }
 733
 734
 735 static int ti_write(struct tty_struct *tty, struct usb_serial_port *port,
 736                         const unsigned char *data, int count)
 737 {
 738         struct ti_port *tport = usb_get_serial_port_data(port);
 739         unsigned long flags;
 740
 741         dbg("%s - port %d", __func__, port->number);
 742
 743         if (count == 0) {
 744                 dbg("%s - write request of 0 bytes", __func__);
 745                 return 0;
 746         }
 747
 748         if (tport == NULL || !tport->tp_is_open)
 749                 return -ENODEV;
 750
 751         spin_lock_irqsave(&tport->tp_lock, flags);
 752         count = ti_buf_put(tport->tp_write_buf, data, count);
 753         spin_unlock_irqrestore(&tport->tp_lock, flags);
 754
 755         ti_send(tport);
 756
 757         return count;
 758 }
 759
 760
 761 static int ti_write_room(struct tty_struct *tty)
 762 {
 763         struct usb_serial_port *port = tty->driver_data;
 764         struct ti_port *tport = usb_get_serial_port_data(port);
 765         int room = 0;
 766         unsigned long flags;
 767
 768         dbg("%s - port %d", __func__, port->number);
 769
 770         if (tport == NULL)
 771                 return -ENODEV;
 772
 773         spin_lock_irqsave(&tport->tp_lock, flags);
 774         room = ti_buf_space_avail(tport->tp_write_buf);
 775         spin_unlock_irqrestore(&tport->tp_lock, flags);
 776
 777         dbg("%s - returns %d", __func__, room);
 778         return room;
 779 }
 780
 781
 782 static int ti_chars_in_buffer(struct tty_struct *tty)
 783 {
 784         struct usb_serial_port *port = tty->driver_data;
 785         struct ti_port *tport = usb_get_serial_port_data(port);
 786         int chars = 0;
 787         unsigned long flags;
 788
 789         dbg("%s - port %d", __func__, port->number);
 790
 791         if (tport == NULL)
 792                 return -ENODEV;
 793
 794         spin_lock_irqsave(&tport->tp_lock, flags);
 795         chars = ti_buf_data_avail(tport->tp_write_buf);
 796         spin_unlock_irqrestore(&tport->tp_lock, flags);
 797
 798         dbg("%s - returns %d", __func__, chars);
 799         return chars;
 800 }
 801
 802
 803 static void ti_throttle(struct tty_struct *tty)
 804 {
 805         struct usb_serial_port *port = tty->driver_data;
 806         struct ti_port *tport = usb_get_serial_port_data(port);
 807
 808         dbg("%s - port %d", __func__, port->number);
 809
 810         if (tport == NULL)
 811                 return;
 812
 813         if (I_IXOFF(tty) || C_CRTSCTS(tty))
 814                 ti_stop_read(tport, tty);
 815
 816 }
 817
 818
 819 static void ti_unthrottle(struct tty_struct *tty)
 820 {
 821         struct usb_serial_port *port = tty->driver_data;
 822         struct ti_port *tport = usb_get_serial_port_data(port);
 823         int status;
 824
 825         dbg("%s - port %d", __func__, port->number);
 826
 827         if (tport == NULL)
 828                 return;
 829
 830         if (I_IXOFF(tty) || C_CRTSCTS(tty)) {
 831                 status = ti_restart_read(tport, tty);
 832                 if (status)
 833                         dev_err(&port->dev, "%s - cannot restart read, %d\n",
 834                                                         __func__, status);
 835         }
 836 }
 837
 838
 839 static int ti_ioctl(struct tty_struct *tty, struct file *file,
 840         unsigned int cmd, unsigned long arg)
 841 {
 842         struct usb_serial_port *port = tty->driver_data;
 843         struct ti_port *tport = usb_get_serial_port_data(port);
 844         struct async_icount cnow;
 845         struct async_icount cprev;
 846
 847         dbg("%s - port %d, cmd = 0x%04X", __func__, port->number, cmd);
 848
 849         if (tport == NULL)
 850                 return -ENODEV;
 851
 852         switch (cmd) {
 853         case TIOCGSERIAL:
 854                 dbg("%s - (%d) TIOCGSERIAL", __func__, port->number);
 855                 return ti_get_serial_info(tport,
 856                                 (struct serial_struct __user *)arg);
 857         case TIOCSSERIAL:
 858                 dbg("%s - (%d) TIOCSSERIAL", __func__, port->number);
 859                 return ti_set_serial_info(tty, tport,
 860                                 (struct serial_struct __user *)arg);
 861         case TIOCMIWAIT:
 862                 dbg("%s - (%d) TIOCMIWAIT", __func__, port->number);
 863                 cprev = tport->tp_icount;
 864                 while (1) {
 865                         interruptible_sleep_on(&tport->tp_msr_wait);
 866                         if (signal_pending(current))
 867                                 return -ERESTARTSYS;
 868                         cnow = tport->tp_icount;
 869                         if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
 870                             cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
 871                                 return -EIO; /* no change => error */
 872                         if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 873                             ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 874                             ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
 875                             ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)))
 876                                 return 0;
 877                         cprev = cnow;
 878                 }
 879                 break;
 880         case TIOCGICOUNT:
 881                 dbg("%s - (%d) TIOCGICOUNT RX=%d, TX=%d",
 882                                 __func__, port->number,
 883                                 tport->tp_icount.rx, tport->tp_icount.tx);
 884                 if (copy_to_user((void __user *)arg, &tport->tp_icount,
 885                                         sizeof(tport->tp_icount)))
 886                         return -EFAULT;
 887                 return 0;
 888         }
 889         return -ENOIOCTLCMD;
 890 }
 891
 892
 893 static void ti_set_termios(struct tty_struct *tty,
 894                 struct usb_serial_port *port, struct ktermios *old_termios)
 895 {
 896         struct ti_port *tport = usb_get_serial_port_data(port);
 897         struct ti_uart_config *config;
 898         tcflag_t cflag, iflag;
 899         int baud;
 900         int status;
 901         int port_number = port->number - port->serial->minor;
 902         unsigned int mcr;
 903
 904         dbg("%s - port %d", __func__, port->number);
 905
 906         cflag = tty->termios->c_cflag;
 907         iflag = tty->termios->c_iflag;
 908
 909         dbg("%s - cflag %08x, iflag %08x", __func__, cflag, iflag);
 910         dbg("%s - old clfag %08x, old iflag %08x", __func__,
 911                                 old_termios->c_cflag, old_termios->c_iflag);
 912
 913         if (tport == NULL)
 914                 return;
 915
 916         config = kmalloc(sizeof(*config), GFP_KERNEL);
 917         if (!config) {
 918                 dev_err(&port->dev, "%s - out of memory\n", __func__);
 919                 return;
 920         }
 921
 922         config->wFlags = 0;
 923
 924         /* these flags must be set */
 925         config->wFlags |= TI_UART_ENABLE_MS_INTS;
 926         config->wFlags |= TI_UART_ENABLE_AUTO_START_DMA;
 927         config->bUartMode = (__u8)(tport->tp_uart_mode);
 928
 929         switch (cflag & CSIZE) {
 930         case CS5:
 931                     config->bDataBits = TI_UART_5_DATA_BITS;
 932                     break;
 933         case CS6:
 934                     config->bDataBits = TI_UART_6_DATA_BITS;
 935                     break;
 936         case CS7:
 937                     config->bDataBits = TI_UART_7_DATA_BITS;
 938                     break;
 939         default:
 940         case CS8:
 941                     config->bDataBits = TI_UART_8_DATA_BITS;
 942                     break;
 943         }
 944
 945         /* CMSPAR isn't supported by this driver */
 946         tty->termios->c_cflag &= ~CMSPAR;
 947
 948         if (cflag & PARENB) {
 949                 if (cflag & PARODD) {
 950                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 951                         config->bParity = TI_UART_ODD_PARITY;
 952                 } else {
 953                         config->wFlags |= TI_UART_ENABLE_PARITY_CHECKING;
 954                         config->bParity = TI_UART_EVEN_PARITY;
 955                 }
 956         } else {
 957                 config->wFlags &= ~TI_UART_ENABLE_PARITY_CHECKING;
 958                 config->bParity = TI_UART_NO_PARITY;
 959         }
 960
 961         if (cflag & CSTOPB)
 962                 config->bStopBits = TI_UART_2_STOP_BITS;
 963         else
 964                 config->bStopBits = TI_UART_1_STOP_BITS;
 965
 966         if (cflag & CRTSCTS) {
 967                 /* RTS flow control must be off to drop RTS for baud rate B0 */
 968                 if ((cflag & CBAUD) != B0)
 969                         config->wFlags |= TI_UART_ENABLE_RTS_IN;
 970                 config->wFlags |= TI_UART_ENABLE_CTS_OUT;
 971         } else {
 972                 tty->hw_stopped = 0;
 973                 ti_restart_read(tport, tty);
 974         }
 975
 976         if (I_IXOFF(tty) || I_IXON(tty)) {
 977                 config->cXon  = START_CHAR(tty);
 978                 config->cXoff = STOP_CHAR(tty);
 979
 980                 if (I_IXOFF(tty))
 981                         config->wFlags |= TI_UART_ENABLE_X_IN;
 982                 else
 983                         ti_restart_read(tport, tty);
 984
 985                 if (I_IXON(tty))
 986                         config->wFlags |= TI_UART_ENABLE_X_OUT;
 987         }
 988
 989         baud = tty_get_baud_rate(tty);
 990         if (!baud)
 991                 baud = 9600;
 992         if (tport->tp_tdev->td_is_3410)
 993                 config->wBaudRate = (__u16)((923077 + baud/2) / baud);
 994         else
 995                 config->wBaudRate = (__u16)((461538 + baud/2) / baud);
 996
 997         /* FIXME: Should calculate resulting baud here and report it back */
 998         if ((cflag & CBAUD) != B0)
 999                 tty_encode_baud_rate(tty, baud, baud);
1000
1001         dbg("%s - BaudRate=%d, wBaudRate=%d, wFlags=0x%04X, bDataBits=%d, bParity=%d, bStopBits=%d, cXon=%d, cXoff=%d, bUartMode=%d",
1002         __func__, baud, config->wBaudRate, config->wFlags, config->bDataBits, config->bParity, config->bStopBits, config->cXon, config->cXoff, config->bUartMode);
1003
1004         cpu_to_be16s(&config->wBaudRate);
1005         cpu_to_be16s(&config->wFlags);
1006
1007         status = ti_command_out_sync(tport->tp_tdev, TI_SET_CONFIG,
1008                 (__u8)(TI_UART1_PORT + port_number), 0, (__u8 *)config,
1009                 sizeof(*config));
1010         if (status)
1011                 dev_err(&port->dev, "%s - cannot set config on port %d, %d\n",
1012                                         __func__, port_number, status);
1013
1014         /* SET_CONFIG asserts RTS and DTR, reset them correctly */
1015         mcr = tport->tp_shadow_mcr;
1016         /* if baud rate is B0, clear RTS and DTR */
1017         if ((cflag & CBAUD) == B0)
1018                 mcr &= ~(TI_MCR_DTR | TI_MCR_RTS);
1019         status = ti_set_mcr(tport, mcr);
1020         if (status)
1021                 dev_err(&port->dev,
1022                         "%s - cannot set modem control on port %d, %d\n",
1023                                                 __func__, port_number, status);
1024
1025         kfree(config);
1026 }
1027
1028
1029 static int ti_tiocmget(struct tty_struct *tty, struct file *file)
1030 {
1031         struct usb_serial_port *port = tty->driver_data;
1032         struct ti_port *tport = usb_get_serial_port_data(port);
1033         unsigned int result;
1034         unsigned int msr;
1035         unsigned int mcr;
1036         unsigned long flags;
1037
1038         dbg("%s - port %d", __func__, port->number);
1039
1040         if (tport == NULL)
1041                 return -ENODEV;
1042
1043         spin_lock_irqsave(&tport->tp_lock, flags);
1044         msr = tport->tp_msr;
1045         mcr = tport->tp_shadow_mcr;
1046         spin_unlock_irqrestore(&tport->tp_lock, flags);
1047
1048         result = ((mcr & TI_MCR_DTR) ? TIOCM_DTR : 0)
1049                 | ((mcr & TI_MCR_RTS) ? TIOCM_RTS : 0)
1050                 | ((mcr & TI_MCR_LOOP) ? TIOCM_LOOP : 0)
1051                 | ((msr & TI_MSR_CTS) ? TIOCM_CTS : 0)
1052                 | ((msr & TI_MSR_CD) ? TIOCM_CAR : 0)
1053                 | ((msr & TI_MSR_RI) ? TIOCM_RI : 0)
1054                 | ((msr & TI_MSR_DSR) ? TIOCM_DSR : 0);
1055
1056         dbg("%s - 0x%04X", __func__, result);
1057
1058         return result;
1059 }
1060
1061
1062 static int ti_tiocmset(struct tty_struct *tty, struct file *file,
1063         unsigned int set, unsigned int clear)
1064 {
1065         struct usb_serial_port *port = tty->driver_data;
1066         struct ti_port *tport = usb_get_serial_port_data(port);
1067         unsigned int mcr;
1068         unsigned long flags;
1069
1070         dbg("%s - port %d", __func__, port->number);
1071
1072         if (tport == NULL)
1073                 return -ENODEV;
1074
1075         spin_lock_irqsave(&tport->tp_lock, flags);
1076         mcr = tport->tp_shadow_mcr;
1077
1078         if (set & TIOCM_RTS)
1079                 mcr |= TI_MCR_RTS;
1080         if (set & TIOCM_DTR)
1081                 mcr |= TI_MCR_DTR;
1082         if (set & TIOCM_LOOP)
1083                 mcr |= TI_MCR_LOOP;
1084
1085         if (clear & TIOCM_RTS)
1086                 mcr &= ~TI_MCR_RTS;
1087         if (clear & TIOCM_DTR)
1088                 mcr &= ~TI_MCR_DTR;
1089         if (clear & TIOCM_LOOP)
1090                 mcr &= ~TI_MCR_LOOP;
1091         spin_unlock_irqrestore(&tport->tp_lock, flags);
1092
1093         return ti_set_mcr(tport, mcr);
1094 }
1095
1096
1097 static void ti_break(struct tty_struct *tty, int break_state)
1098 {
1099         struct usb_serial_port *port = tty->driver_data;
1100         struct ti_port *tport = usb_get_serial_port_data(port);
1101         int status;
1102
1103         dbg("%s - state = %d", __func__, break_state);
1104
1105         if (tport == NULL)
1106                 return;
1107
1108         ti_drain(tport, (tport->tp_closing_wait*HZ)/100, 0);
1109
1110         status = ti_write_byte(tport->tp_tdev,
1111                 tport->tp_uart_base_addr + TI_UART_OFFSET_LCR,
1112                 TI_LCR_BREAK, break_state == -1 ? TI_LCR_BREAK : 0);
1113
1114         if (status)
1115                 dbg("%s - error setting break, %d", __func__, status);
1116 }
1117
1118
1119 static void ti_interrupt_callback(struct urb *urb)
1120 {
1121         struct ti_device *tdev = urb->context;
1122         struct usb_serial_port *port;
1123         struct usb_serial *serial = tdev->td_serial;
1124         struct ti_port *tport;
1125         struct device *dev = &urb->dev->dev;
1126         unsigned char *data = urb->transfer_buffer;
1127         int length = urb->actual_length;
1128         int port_number;
1129         int function;
1130         int status = urb->status;
1131         int retval;
1132         __u8 msr;
1133
1134         dbg("%s", __func__);
1135
1136         switch (status) {
1137         case 0:
1138                 break;
1139         case -ECONNRESET:
1140         case -ENOENT:
1141         case -ESHUTDOWN:
1142                 dbg("%s - urb shutting down, %d", __func__, status);
1143                 tdev->td_urb_error = 1;
1144                 return;
1145         default:
1146                 dev_err(dev, "%s - nonzero urb status, %d\n",
1147                         __func__, status);
1148                 tdev->td_urb_error = 1;
1149                 goto exit;
1150         }
1151
1152         if (length != 2) {
1153                 dbg("%s - bad packet size, %d", __func__, length);
1154                 goto exit;
1155         }
1156
1157         if (data[0] == TI_CODE_HARDWARE_ERROR) {
1158                 dev_err(dev, "%s - hardware error, %d\n", __func__, data[1]);
1159                 goto exit;
1160         }
1161
1162         port_number = TI_GET_PORT_FROM_CODE(data[0]);
1163         function = TI_GET_FUNC_FROM_CODE(data[0]);
1164
1165         dbg("%s - port_number %d, function %d, data 0x%02X",
1166                                 __func__, port_number, function, data[1]);
1167
1168         if (port_number >= serial->num_ports) {
1169                 dev_err(dev, "%s - bad port number, %d\n",
1170                                                 __func__, port_number);
1171                 goto exit;
1172         }
1173
1174         port = serial->port[port_number];
1175
1176         tport = usb_get_serial_port_data(port);
1177         if (!tport)
1178                 goto exit;
1179
1180         switch (function) {
1181         case TI_CODE_DATA_ERROR:
1182                 dev_err(dev, "%s - DATA ERROR, port %d, data 0x%02X\n",
1183                                         __func__, port_number, data[1]);
1184                 break;
1185
1186         case TI_CODE_MODEM_STATUS:
1187                 msr = data[1];
1188                 dbg("%s - port %d, msr 0x%02X", __func__, port_number, msr);
1189                 ti_handle_new_msr(tport, msr);
1190                 break;
1191
1192         default:
1193                 dev_err(dev, "%s - unknown interrupt code, 0x%02X\n",
1194                                                         __func__, data[1]);
1195                 break;
1196         }
1197
1198 exit:
1199         retval = usb_submit_urb(urb, GFP_ATOMIC);
1200         if (retval)
1201                 dev_err(dev, "%s - resubmit interrupt urb failed, %d\n",
1202                         __func__, retval);
1203 }
1204
1205
1206 static void ti_bulk_in_callback(struct urb *urb)
1207 {
1208         struct ti_port *tport = urb->context;
1209         struct usb_serial_port *port = tport->tp_port;
1210         struct device *dev = &urb->dev->dev;
1211         int status = urb->status;
1212         int retval = 0;
1213         struct tty_struct *tty;
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         tty = tty_port_tty_get(&port->port);
1243         if (tty && urb->actual_length) {
1244                 usb_serial_debug_data(debug, dev, __func__,
1245                         urb->actual_length, urb->transfer_buffer);
1246
1247                 if (!tport->tp_is_open)
1248                         dbg("%s - port closed, dropping data", __func__);
1249                 else
1250                         ti_recv(&urb->dev->dev, tty,
1251                                                 urb->transfer_buffer,
1252                                                 urb->actual_length);
1253
1254                 spin_lock(&tport->tp_lock);
1255                 tport->tp_icount.rx += urb->actual_length;
1256                 spin_unlock(&tport->tp_lock);
1257                 tty_kref_put(tty);
1258         }
1259
1260 exit:
1261         /* continue to read unless stopping */
1262         spin_lock(&tport->tp_lock);
1263         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING) {
1264                 urb->dev = port->serial->dev;
1265                 retval = usb_submit_urb(urb, GFP_ATOMIC);
1266         } else if (tport->tp_read_urb_state == TI_READ_URB_STOPPING) {
1267                 tport->tp_read_urb_state = TI_READ_URB_STOPPED;
1268         }
1269         spin_unlock(&tport->tp_lock);
1270         if (retval)
1271                 dev_err(dev, "%s - resubmit read urb failed, %d\n",
1272                         __func__, retval);
1273 }
1274
1275
1276 static void ti_bulk_out_callback(struct urb *urb)
1277 {
1278         struct ti_port *tport = urb->context;
1279         struct usb_serial_port *port = tport->tp_port;
1280         struct device *dev = &urb->dev->dev;
1281         int status = urb->status;
1282
1283         dbg("%s - port %d", __func__, port->number);
1284
1285         tport->tp_write_urb_in_use = 0;
1286
1287         switch (status) {
1288         case 0:
1289                 break;
1290         case -ECONNRESET:
1291         case -ENOENT:
1292         case -ESHUTDOWN:
1293                 dbg("%s - urb shutting down, %d", __func__, status);
1294                 tport->tp_tdev->td_urb_error = 1;
1295                 wake_up_interruptible(&tport->tp_write_wait);
1296                 return;
1297         default:
1298                 dev_err(dev, "%s - nonzero urb status, %d\n",
1299                         __func__, status);
1300                 tport->tp_tdev->td_urb_error = 1;
1301                 wake_up_interruptible(&tport->tp_write_wait);
1302         }
1303
1304         /* send any buffered data */
1305         ti_send(tport);
1306 }
1307
1308
1309 static void ti_recv(struct device *dev, struct tty_struct *tty,
1310         unsigned char *data, int length)
1311 {
1312         int cnt;
1313
1314         do {
1315                 cnt = tty_buffer_request_room(tty, length);
1316                 if (cnt < length) {
1317                         dev_err(dev, "%s - dropping data, %d bytes lost\n",
1318                                                 __func__, length - cnt);
1319                         if (cnt == 0)
1320                                 break;
1321                 }
1322                 tty_insert_flip_string(tty, data, cnt);
1323                 tty_flip_buffer_push(tty);
1324                 data += cnt;
1325                 length -= cnt;
1326         } while (length > 0);
1327
1328 }
1329
1330
1331 static void ti_send(struct ti_port *tport)
1332 {
1333         int count, result;
1334         struct usb_serial_port *port = tport->tp_port;
1335         struct tty_struct *tty = tty_port_tty_get(&port->port); /* FIXME */
1336         unsigned long flags;
1337
1338
1339         dbg("%s - port %d", __func__, port->number);
1340
1341         spin_lock_irqsave(&tport->tp_lock, flags);
1342
1343         if (tport->tp_write_urb_in_use)
1344                 goto unlock;
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                 goto unlock;
1352
1353         tport->tp_write_urb_in_use = 1;
1354
1355         spin_unlock_irqrestore(&tport->tp_lock, flags);
1356
1357         usb_serial_debug_data(debug, &port->dev, __func__, count,
1358                                         port->write_urb->transfer_buffer);
1359
1360         usb_fill_bulk_urb(port->write_urb, port->serial->dev,
1361                            usb_sndbulkpipe(port->serial->dev,
1362                                             port->bulk_out_endpointAddress),
1363                            port->write_urb->transfer_buffer, count,
1364                            ti_bulk_out_callback, tport);
1365
1366         result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
1367         if (result) {
1368                 dev_err(&port->dev, "%s - submit write urb failed, %d\n",
1369                                                         __func__, result);
1370                 tport->tp_write_urb_in_use = 0;
1371                 /* TODO: reschedule ti_send */
1372         } else {
1373                 spin_lock_irqsave(&tport->tp_lock, flags);
1374                 tport->tp_icount.tx += count;
1375                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1376         }
1377
1378         /* more room in the buffer for new writes, wakeup */
1379         if (tty)
1380                 tty_wakeup(tty);
1381         tty_kref_put(tty);
1382         wake_up_interruptible(&tport->tp_write_wait);
1383         return;
1384 unlock:
1385         spin_unlock_irqrestore(&tport->tp_lock, flags);
1386         tty_kref_put(tty);
1387         return;
1388 }
1389
1390
1391 static int ti_set_mcr(struct ti_port *tport, unsigned int mcr)
1392 {
1393         unsigned long flags;
1394         int status;
1395
1396         status = ti_write_byte(tport->tp_tdev,
1397                 tport->tp_uart_base_addr + TI_UART_OFFSET_MCR,
1398                 TI_MCR_RTS | TI_MCR_DTR | TI_MCR_LOOP, mcr);
1399
1400         spin_lock_irqsave(&tport->tp_lock, flags);
1401         if (!status)
1402                 tport->tp_shadow_mcr = mcr;
1403         spin_unlock_irqrestore(&tport->tp_lock, flags);
1404
1405         return status;
1406 }
1407
1408
1409 static int ti_get_lsr(struct ti_port *tport)
1410 {
1411         int size, status;
1412         struct ti_device *tdev = tport->tp_tdev;
1413         struct usb_serial_port *port = tport->tp_port;
1414         int port_number = port->number - port->serial->minor;
1415         struct ti_port_status *data;
1416
1417         dbg("%s - port %d", __func__, port->number);
1418
1419         size = sizeof(struct ti_port_status);
1420         data = kmalloc(size, GFP_KERNEL);
1421         if (!data) {
1422                 dev_err(&port->dev, "%s - out of memory\n", __func__);
1423                 return -ENOMEM;
1424         }
1425
1426         status = ti_command_in_sync(tdev, TI_GET_PORT_STATUS,
1427                 (__u8)(TI_UART1_PORT+port_number), 0, (__u8 *)data, size);
1428         if (status) {
1429                 dev_err(&port->dev,
1430                         "%s - get port status command failed, %d\n",
1431                                                         __func__, status);
1432                 goto free_data;
1433         }
1434
1435         dbg("%s - lsr 0x%02X", __func__, data->bLSR);
1436
1437         tport->tp_lsr = data->bLSR;
1438
1439 free_data:
1440         kfree(data);
1441         return status;
1442 }
1443
1444
1445 static int ti_get_serial_info(struct ti_port *tport,
1446         struct serial_struct __user *ret_arg)
1447 {
1448         struct usb_serial_port *port = tport->tp_port;
1449         struct serial_struct ret_serial;
1450
1451         if (!ret_arg)
1452                 return -EFAULT;
1453
1454         memset(&ret_serial, 0, sizeof(ret_serial));
1455
1456         ret_serial.type = PORT_16550A;
1457         ret_serial.line = port->serial->minor;
1458         ret_serial.port = port->number - port->serial->minor;
1459         ret_serial.flags = tport->tp_flags;
1460         ret_serial.xmit_fifo_size = TI_WRITE_BUF_SIZE;
1461         ret_serial.baud_base = tport->tp_tdev->td_is_3410 ? 921600 : 460800;
1462         ret_serial.closing_wait = tport->tp_closing_wait;
1463
1464         if (copy_to_user(ret_arg, &ret_serial, sizeof(*ret_arg)))
1465                 return -EFAULT;
1466
1467         return 0;
1468 }
1469
1470
1471 static int ti_set_serial_info(struct tty_struct *tty, struct ti_port *tport,
1472         struct serial_struct __user *new_arg)
1473 {
1474         struct serial_struct new_serial;
1475
1476         if (copy_from_user(&new_serial, new_arg, sizeof(new_serial)))
1477                 return -EFAULT;
1478
1479         tport->tp_flags = new_serial.flags & TI_SET_SERIAL_FLAGS;
1480         tty->low_latency = (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 = tty_port_tty_get(&tport->tp_port->port);
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         tty_kref_put(tty);
1523 }
1524
1525
1526 static void ti_drain(struct ti_port *tport, unsigned long timeout, int flush)
1527 {
1528         struct ti_device *tdev = tport->tp_tdev;
1529         struct usb_serial_port *port = tport->tp_port;
1530         wait_queue_t wait;
1531
1532         dbg("%s - port %d", __func__, port->number);
1533
1534         spin_lock_irq(&tport->tp_lock);
1535
1536         /* wait for data to drain from the buffer */
1537         tdev->td_urb_error = 0;
1538         init_waitqueue_entry(&wait, current);
1539         add_wait_queue(&tport->tp_write_wait, &wait);
1540         for (;;) {
1541                 set_current_state(TASK_INTERRUPTIBLE);
1542                 if (ti_buf_data_avail(tport->tp_write_buf) == 0
1543                 || timeout == 0 || signal_pending(current)
1544                 || tdev->td_urb_error
1545                 || port->serial->disconnected)  /* disconnect */
1546                         break;
1547                 spin_unlock_irq(&tport->tp_lock);
1548                 timeout = schedule_timeout(timeout);
1549                 spin_lock_irq(&tport->tp_lock);
1550         }
1551         set_current_state(TASK_RUNNING);
1552         remove_wait_queue(&tport->tp_write_wait, &wait);
1553
1554         /* flush any remaining data in the buffer */
1555         if (flush)
1556                 ti_buf_clear(tport->tp_write_buf);
1557
1558         spin_unlock_irq(&tport->tp_lock);
1559
1560         mutex_lock(&port->serial->disc_mutex);
1561         /* wait for data to drain from the device */
1562         /* wait for empty tx register, plus 20 ms */
1563         timeout += jiffies;
1564         tport->tp_lsr &= ~TI_LSR_TX_EMPTY;
1565         while ((long)(jiffies - timeout) < 0 && !signal_pending(current)
1566         && !(tport->tp_lsr&TI_LSR_TX_EMPTY) && !tdev->td_urb_error
1567         && !port->serial->disconnected) {
1568                 if (ti_get_lsr(tport))
1569                         break;
1570                 mutex_unlock(&port->serial->disc_mutex);
1571                 msleep_interruptible(20);
1572                 mutex_lock(&port->serial->disc_mutex);
1573         }
1574         mutex_unlock(&port->serial->disc_mutex);
1575 }
1576
1577
1578 static void ti_stop_read(struct ti_port *tport, struct tty_struct *tty)
1579 {
1580         unsigned long flags;
1581
1582         spin_lock_irqsave(&tport->tp_lock, flags);
1583
1584         if (tport->tp_read_urb_state == TI_READ_URB_RUNNING)
1585                 tport->tp_read_urb_state = TI_READ_URB_STOPPING;
1586
1587         spin_unlock_irqrestore(&tport->tp_lock, flags);
1588 }
1589
1590
1591 static int ti_restart_read(struct ti_port *tport, struct tty_struct *tty)
1592 {
1593         struct urb *urb;
1594         int status = 0;
1595         unsigned long flags;
1596
1597         spin_lock_irqsave(&tport->tp_lock, flags);
1598
1599         if (tport->tp_read_urb_state == TI_READ_URB_STOPPED) {
1600                 tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1601                 urb = tport->tp_port->read_urb;
1602                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1603                 urb->complete = ti_bulk_in_callback;
1604                 urb->context = tport;
1605                 urb->dev = tport->tp_port->serial->dev;
1606                 status = usb_submit_urb(urb, GFP_KERNEL);
1607         } else  {
1608                 tport->tp_read_urb_state = TI_READ_URB_RUNNING;
1609                 spin_unlock_irqrestore(&tport->tp_lock, flags);
1610         }
1611
1612         return status;
1613 }
1614
1615
1616 static int ti_command_out_sync(struct ti_device *tdev, __u8 command,
1617         __u16 moduleid, __u16 value, __u8 *data, int size)
1618 {
1619         int status;
1620
1621         status = usb_control_msg(tdev->td_serial->dev,
1622                 usb_sndctrlpipe(tdev->td_serial->dev, 0), command,
1623                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT),
1624                 value, moduleid, data, size, 1000);
1625
1626         if (status == size)
1627                 status = 0;
1628
1629         if (status > 0)
1630                 status = -ECOMM;
1631
1632         return status;
1633 }
1634
1635
1636 static int ti_command_in_sync(struct ti_device *tdev, __u8 command,
1637         __u16 moduleid, __u16 value, __u8 *data, int size)
1638 {
1639         int status;
1640
1641         status = usb_control_msg(tdev->td_serial->dev,
1642                 usb_rcvctrlpipe(tdev->td_serial->dev, 0), command,
1643                 (USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN),
1644                 value, moduleid, data, size, 1000);
1645
1646         if (status == size)
1647                 status = 0;
1648
1649         if (status > 0)
1650                 status = -ECOMM;
1651
1652         return status;
1653 }
1654
1655
1656 static int ti_write_byte(struct ti_device *tdev, unsigned long addr,
1657         __u8 mask, __u8 byte)
1658 {
1659         int status;
1660         unsigned int size;
1661         struct ti_write_data_bytes *data;
1662         struct device *dev = &tdev->td_serial->dev->dev;
1663
1664         dbg("%s - addr 0x%08lX, mask 0x%02X, byte 0x%02X",
1665                                         __func__, addr, mask, byte);
1666
1667         size = sizeof(struct ti_write_data_bytes) + 2;
1668         data = kmalloc(size, GFP_KERNEL);
1669         if (!data) {
1670                 dev_err(dev, "%s - out of memory\n", __func__);
1671                 return -ENOMEM;
1672         }
1673
1674         data->bAddrType = TI_RW_DATA_ADDR_XDATA;
1675         data->bDataType = TI_RW_DATA_BYTE;
1676         data->bDataCounter = 1;
1677         data->wBaseAddrHi = cpu_to_be16(addr>>16);
1678         data->wBaseAddrLo = cpu_to_be16(addr);
1679         data->bData[0] = mask;
1680         data->bData[1] = byte;
1681
1682         status = ti_command_out_sync(tdev, TI_WRITE_DATA, TI_RAM_PORT, 0,
1683                 (__u8 *)data, size);
1684
1685         if (status < 0)
1686                 dev_err(dev, "%s - failed, %d\n", __func__, status);
1687
1688         kfree(data);
1689
1690         return status;
1691 }
1692
1693 static int ti_do_download(struct usb_device *dev, int pipe,
1694                                                 u8 *buffer, int size)
1695 {
1696         int pos;
1697         u8 cs = 0;
1698         int done;
1699         struct ti_firmware_header *header;
1700         int status;
1701         int len;
1702
1703         for (pos = sizeof(struct ti_firmware_header); pos < size; pos++)
1704                 cs = (__u8)(cs + buffer[pos]);
1705
1706         header = (struct ti_firmware_header *)buffer;
1707         header->wLength = cpu_to_le16((__u16)(size
1708                                         - sizeof(struct ti_firmware_header)));
1709         header->bCheckSum = cs;
1710
1711         dbg("%s - downloading firmware", __func__);
1712         for (pos = 0; pos < size; pos += done) {
1713                 len = min(size - pos, TI_DOWNLOAD_MAX_PACKET_SIZE);
1714                 status = usb_bulk_msg(dev, pipe, buffer + pos, len,
1715                                                                 &done, 1000);
1716                 if (status)
1717                         break;
1718         }
1719         return status;
1720 }
1721
1722 static int ti_download_firmware(struct ti_device *tdev, int type)
1723 {
1724         int status = -ENOMEM;
1725         int buffer_size;
1726         __u8 *buffer;
1727         struct usb_device *dev = tdev->td_serial->dev;
1728         unsigned int pipe = usb_sndbulkpipe(dev,
1729                 tdev->td_serial->port[0]->bulk_out_endpointAddress);
1730         const struct firmware *fw_p;
1731         char buf[32];
1732         sprintf(buf, "ti_usb-%d.bin", type);
1733
1734         if (request_firmware(&fw_p, buf, &dev->dev)) {
1735                 dev_err(&dev->dev, "%s - firmware not found\n", __func__);
1736                 return -ENOENT;
1737         }
1738         if (fw_p->size > TI_FIRMWARE_BUF_SIZE) {
1739                 dev_err(&dev->dev, "%s - firmware too large\n", __func__);
1740                 return -ENOENT;
1741         }
1742
1743         buffer_size = TI_FIRMWARE_BUF_SIZE + sizeof(struct ti_firmware_header);
1744         buffer = kmalloc(buffer_size, GFP_KERNEL);
1745         if (buffer) {
1746                 memcpy(buffer, fw_p->data, fw_p->size);
1747                 memset(buffer + fw_p->size, 0xff, buffer_size - fw_p->size);
1748                 status = ti_do_download(dev, pipe, buffer, fw_p->size);
1749                 kfree(buffer);
1750         }
1751         release_firmware(fw_p);
1752         if (status) {
1753                 dev_err(&dev->dev, "%s - error downloading firmware, %d\n",
1754                                                         __func__, status);
1755                 return status;
1756         }
1757
1758         dbg("%s - download successful", __func__);
1759
1760         return 0;
1761 }
1762
1763
1764 /* Circular Buffer Functions */
1765
1766 /*
1767  * ti_buf_alloc
1768  *
1769  * Allocate a circular buffer and all associated memory.
1770  */
1771
1772 static struct circ_buf *ti_buf_alloc(void)
1773 {
1774         struct circ_buf *cb;
1775
1776         cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
1777         if (cb == NULL)
1778                 return NULL;
1779
1780         cb->buf = kmalloc(TI_WRITE_BUF_SIZE, GFP_KERNEL);
1781         if (cb->buf == NULL) {
1782                 kfree(cb);
1783                 return NULL;
1784         }
1785
1786         ti_buf_clear(cb);
1787
1788         return cb;
1789 }
1790
1791
1792 /*
1793  * ti_buf_free
1794  *
1795  * Free the buffer and all associated memory.
1796  */
1797
1798 static void ti_buf_free(struct circ_buf *cb)
1799 {
1800         kfree(cb->buf);
1801         kfree(cb);
1802 }
1803
1804
1805 /*
1806  * ti_buf_clear
1807  *
1808  * Clear out all data in the circular buffer.
1809  */
1810
1811 static void ti_buf_clear(struct circ_buf *cb)
1812 {
1813         cb->head = cb->tail = 0;
1814 }
1815
1816
1817 /*
1818  * ti_buf_data_avail
1819  *
1820  * Return the number of bytes of data available in the circular
1821  * buffer.
1822  */
1823
1824 static int ti_buf_data_avail(struct circ_buf *cb)
1825 {
1826         return CIRC_CNT(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1827 }
1828
1829
1830 /*
1831  * ti_buf_space_avail
1832  *
1833  * Return the number of bytes of space available in the circular
1834  * buffer.
1835  */
1836
1837 static int ti_buf_space_avail(struct circ_buf *cb)
1838 {
1839         return CIRC_SPACE(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1840 }
1841
1842
1843 /*
1844  * ti_buf_put
1845  *
1846  * Copy data data from a user buffer and put it into the circular buffer.
1847  * Restrict to the amount of space available.
1848  *
1849  * Return the number of bytes copied.
1850  */
1851
1852 static int ti_buf_put(struct circ_buf *cb, const char *buf, int count)
1853 {
1854         int c, ret = 0;
1855
1856         while (1) {
1857                 c = CIRC_SPACE_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1858                 if (count < c)
1859                         c = count;
1860                 if (c <= 0)
1861                         break;
1862                 memcpy(cb->buf + cb->head, buf, c);
1863                 cb->head = (cb->head + c) & (TI_WRITE_BUF_SIZE-1);
1864                 buf += c;
1865                 count -= c;
1866                 ret += c;
1867         }
1868
1869         return ret;
1870 }
1871
1872
1873 /*
1874  * ti_buf_get
1875  *
1876  * Get data from the circular buffer and copy to the given buffer.
1877  * Restrict to the amount of data available.
1878  *
1879  * Return the number of bytes copied.
1880  */
1881
1882 static int ti_buf_get(struct circ_buf *cb, char *buf, int count)
1883 {
1884         int c, ret = 0;
1885
1886         while (1) {
1887                 c = CIRC_CNT_TO_END(cb->head, cb->tail, TI_WRITE_BUF_SIZE);
1888                 if (count < c)
1889                         c = count;
1890                 if (c <= 0)
1891                         break;
1892                 memcpy(buf, cb->buf + cb->tail, c);
1893                 cb->tail = (cb->tail + c) & (TI_WRITE_BUF_SIZE-1);
1894                 buf += c;
1895                 count -= c;
1896                 ret += c;
1897         }
1898
1899         return ret;
1900 }