kernel/drivers/tty/serial/jsm/jsm_cls.c

   1 /*
   2  * Copyright 2003 Digi International (www.digi.com)
   3  *      Scott H Kilau <Scott_Kilau at digi dot com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
  12  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  13  * PURPOSE.  See the GNU General Public License for more details.
  14  *
  15  *      NOTE TO LINUX KERNEL HACKERS:  DO NOT REFORMAT THIS CODE!
  16  *
  17  *      This is shared code between Digi's CVS archive and the
  18  *      Linux Kernel sources.
  19  *      Changing the source just for reformatting needlessly breaks
  20  *      our CVS diff history.
  21  *
  22  *      Send any bug fixes/changes to:  Eng.Linux at digi dot com.
  23  *      Thank you.
  24  *
  25  */
  26
  27 #include <linux/delay.h>        /* For udelay */
  28 #include <linux/io.h>           /* For read[bwl]/write[bwl] */
  29 #include <linux/serial.h>       /* For struct async_serial */
  30 #include <linux/serial_reg.h>   /* For the various UART offsets */
  31 #include <linux/pci.h>
  32 #include <linux/tty.h>
  33
  34 #include "jsm.h"        /* Driver main header file */
  35
  36 static struct {
  37         unsigned int rate;
  38         unsigned int cflag;
  39 } baud_rates[] = {
  40         { 921600, B921600 },
  41         { 460800, B460800 },
  42         { 230400, B230400 },
  43         { 115200, B115200 },
  44         {  57600, B57600  },
  45         {  38400, B38400  },
  46         {  19200, B19200  },
  47         {   9600, B9600   },
  48         {   4800, B4800   },
  49         {   2400, B2400   },
  50         {   1200, B1200   },
  51         {    600, B600    },
  52         {    300, B300    },
  53         {    200, B200    },
  54         {    150, B150    },
  55         {    134, B134    },
  56         {    110, B110    },
  57         {     75, B75     },
  58         {     50, B50     },
  59 };
  60
  61 static void cls_set_cts_flow_control(struct jsm_channel *ch)
  62 {
  63         u8 lcrb = readb(&ch->ch_cls_uart->lcr);
  64         u8 ier = readb(&ch->ch_cls_uart->ier);
  65         u8 isr_fcr = 0;
  66
  67         /*
  68          * The Enhanced Register Set may only be accessed when
  69          * the Line Control Register is set to 0xBFh.
  70          */
  71         writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
  72
  73         isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
  74
  75         /* Turn on CTS flow control, turn off IXON flow control */
  76         isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_CTSDSR);
  77         isr_fcr &= ~(UART_EXAR654_EFR_IXON);
  78
  79         writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
  80
  81         /* Write old LCR value back out, which turns enhanced access off */
  82         writeb(lcrb, &ch->ch_cls_uart->lcr);
  83
  84         /*
  85          * Enable interrupts for CTS flow, turn off interrupts for
  86          * received XOFF chars
  87          */
  88         ier |= (UART_EXAR654_IER_CTSDSR);
  89         ier &= ~(UART_EXAR654_IER_XOFF);
  90         writeb(ier, &ch->ch_cls_uart->ier);
  91
  92         /* Set the usual FIFO values */
  93         writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
  94
  95         writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
  96                 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
  97                 &ch->ch_cls_uart->isr_fcr);
  98
  99         ch->ch_t_tlevel = 16;
 100 }
 101
 102 static void cls_set_ixon_flow_control(struct jsm_channel *ch)
 103 {
 104         u8 lcrb = readb(&ch->ch_cls_uart->lcr);
 105         u8 ier = readb(&ch->ch_cls_uart->ier);
 106         u8 isr_fcr = 0;
 107
 108         /*
 109          * The Enhanced Register Set may only be accessed when
 110          * the Line Control Register is set to 0xBFh.
 111          */
 112         writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
 113
 114         isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
 115
 116         /* Turn on IXON flow control, turn off CTS flow control */
 117         isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXON);
 118         isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR);
 119
 120         writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
 121
 122         /* Now set our current start/stop chars while in enhanced mode */
 123         writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
 124         writeb(0, &ch->ch_cls_uart->lsr);
 125         writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
 126         writeb(0, &ch->ch_cls_uart->spr);
 127
 128         /* Write old LCR value back out, which turns enhanced access off */
 129         writeb(lcrb, &ch->ch_cls_uart->lcr);
 130
 131         /*
 132          * Disable interrupts for CTS flow, turn on interrupts for
 133          * received XOFF chars
 134          */
 135         ier &= ~(UART_EXAR654_IER_CTSDSR);
 136         ier |= (UART_EXAR654_IER_XOFF);
 137         writeb(ier, &ch->ch_cls_uart->ier);
 138
 139         /* Set the usual FIFO values */
 140         writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
 141
 142         writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
 143                 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
 144                 &ch->ch_cls_uart->isr_fcr);
 145 }
 146
 147 static void cls_set_no_output_flow_control(struct jsm_channel *ch)
 148 {
 149         u8 lcrb = readb(&ch->ch_cls_uart->lcr);
 150         u8 ier = readb(&ch->ch_cls_uart->ier);
 151         u8 isr_fcr = 0;
 152
 153         /*
 154          * The Enhanced Register Set may only be accessed when
 155          * the Line Control Register is set to 0xBFh.
 156          */
 157         writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
 158
 159         isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
 160
 161         /* Turn off IXON flow control, turn off CTS flow control */
 162         isr_fcr |= (UART_EXAR654_EFR_ECB);
 163         isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR | UART_EXAR654_EFR_IXON);
 164
 165         writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
 166
 167         /* Write old LCR value back out, which turns enhanced access off */
 168         writeb(lcrb, &ch->ch_cls_uart->lcr);
 169
 170         /*
 171          * Disable interrupts for CTS flow, turn off interrupts for
 172          * received XOFF chars
 173          */
 174         ier &= ~(UART_EXAR654_IER_CTSDSR);
 175         ier &= ~(UART_EXAR654_IER_XOFF);
 176         writeb(ier, &ch->ch_cls_uart->ier);
 177
 178         /* Set the usual FIFO values */
 179         writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
 180
 181         writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
 182                 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
 183                 &ch->ch_cls_uart->isr_fcr);
 184
 185         ch->ch_r_watermark = 0;
 186         ch->ch_t_tlevel = 16;
 187         ch->ch_r_tlevel = 16;
 188 }
 189
 190 static void cls_set_rts_flow_control(struct jsm_channel *ch)
 191 {
 192         u8 lcrb = readb(&ch->ch_cls_uart->lcr);
 193         u8 ier = readb(&ch->ch_cls_uart->ier);
 194         u8 isr_fcr = 0;
 195
 196         /*
 197          * The Enhanced Register Set may only be accessed when
 198          * the Line Control Register is set to 0xBFh.
 199          */
 200         writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
 201
 202         isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
 203
 204         /* Turn on RTS flow control, turn off IXOFF flow control */
 205         isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_RTSDTR);
 206         isr_fcr &= ~(UART_EXAR654_EFR_IXOFF);
 207
 208         writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
 209
 210         /* Write old LCR value back out, which turns enhanced access off */
 211         writeb(lcrb, &ch->ch_cls_uart->lcr);
 212
 213         /* Enable interrupts for RTS flow */
 214         ier |= (UART_EXAR654_IER_RTSDTR);
 215         writeb(ier, &ch->ch_cls_uart->ier);
 216
 217         /* Set the usual FIFO values */
 218         writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
 219
 220         writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
 221                 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
 222                 &ch->ch_cls_uart->isr_fcr);
 223
 224         ch->ch_r_watermark = 4;
 225         ch->ch_r_tlevel = 8;
 226 }
 227
 228 static void cls_set_ixoff_flow_control(struct jsm_channel *ch)
 229 {
 230         u8 lcrb = readb(&ch->ch_cls_uart->lcr);
 231         u8 ier = readb(&ch->ch_cls_uart->ier);
 232         u8 isr_fcr = 0;
 233
 234         /*
 235          * The Enhanced Register Set may only be accessed when
 236          * the Line Control Register is set to 0xBFh.
 237          */
 238         writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
 239
 240         isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
 241
 242         /* Turn on IXOFF flow control, turn off RTS flow control */
 243         isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXOFF);
 244         isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR);
 245
 246         writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
 247
 248         /* Now set our current start/stop chars while in enhanced mode */
 249         writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
 250         writeb(0, &ch->ch_cls_uart->lsr);
 251         writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
 252         writeb(0, &ch->ch_cls_uart->spr);
 253
 254         /* Write old LCR value back out, which turns enhanced access off */
 255         writeb(lcrb, &ch->ch_cls_uart->lcr);
 256
 257         /* Disable interrupts for RTS flow */
 258         ier &= ~(UART_EXAR654_IER_RTSDTR);
 259         writeb(ier, &ch->ch_cls_uart->ier);
 260
 261         /* Set the usual FIFO values */
 262         writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
 263
 264         writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
 265                 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
 266                 &ch->ch_cls_uart->isr_fcr);
 267 }
 268
 269 static void cls_set_no_input_flow_control(struct jsm_channel *ch)
 270 {
 271         u8 lcrb = readb(&ch->ch_cls_uart->lcr);
 272         u8 ier = readb(&ch->ch_cls_uart->ier);
 273         u8 isr_fcr = 0;
 274
 275         /*
 276          * The Enhanced Register Set may only be accessed when
 277          * the Line Control Register is set to 0xBFh.
 278          */
 279         writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
 280
 281         isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
 282
 283         /* Turn off IXOFF flow control, turn off RTS flow control */
 284         isr_fcr |= (UART_EXAR654_EFR_ECB);
 285         isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR | UART_EXAR654_EFR_IXOFF);
 286
 287         writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
 288
 289         /* Write old LCR value back out, which turns enhanced access off */
 290         writeb(lcrb, &ch->ch_cls_uart->lcr);
 291
 292         /* Disable interrupts for RTS flow */
 293         ier &= ~(UART_EXAR654_IER_RTSDTR);
 294         writeb(ier, &ch->ch_cls_uart->ier);
 295
 296         /* Set the usual FIFO values */
 297         writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
 298
 299         writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
 300                 UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
 301                 &ch->ch_cls_uart->isr_fcr);
 302
 303         ch->ch_t_tlevel = 16;
 304         ch->ch_r_tlevel = 16;
 305 }
 306
 307 /*
 308  * cls_clear_break.
 309  * Determines whether its time to shut off break condition.
 310  *
 311  * No locks are assumed to be held when calling this function.
 312  * channel lock is held and released in this function.
 313  */
 314 static void cls_clear_break(struct jsm_channel *ch)
 315 {
 316         unsigned long lock_flags;
 317
 318         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 319
 320         /* Turn break off, and unset some variables */
 321         if (ch->ch_flags & CH_BREAK_SENDING) {
 322                 u8 temp = readb(&ch->ch_cls_uart->lcr);
 323
 324                 writeb((temp & ~UART_LCR_SBC), &ch->ch_cls_uart->lcr);
 325
 326                 ch->ch_flags &= ~(CH_BREAK_SENDING);
 327                 jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
 328                         "clear break Finishing UART_LCR_SBC! finished: %lx\n",
 329                         jiffies);
 330         }
 331         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 332 }
 333
 334 static void cls_disable_receiver(struct jsm_channel *ch)
 335 {
 336         u8 tmp = readb(&ch->ch_cls_uart->ier);
 337
 338         tmp &= ~(UART_IER_RDI);
 339         writeb(tmp, &ch->ch_cls_uart->ier);
 340 }
 341
 342 static void cls_enable_receiver(struct jsm_channel *ch)
 343 {
 344         u8 tmp = readb(&ch->ch_cls_uart->ier);
 345
 346         tmp |= (UART_IER_RDI);
 347         writeb(tmp, &ch->ch_cls_uart->ier);
 348 }
 349
 350 /* Make the UART raise any of the output signals we want up */
 351 static void cls_assert_modem_signals(struct jsm_channel *ch)
 352 {
 353         if (!ch)
 354                 return;
 355
 356         writeb(ch->ch_mostat, &ch->ch_cls_uart->mcr);
 357 }
 358
 359 static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
 360 {
 361         int qleft = 0;
 362         u8 linestatus = 0;
 363         u8 error_mask = 0;
 364         u16 head;
 365         u16 tail;
 366         unsigned long flags;
 367
 368         if (!ch)
 369                 return;
 370
 371         spin_lock_irqsave(&ch->ch_lock, flags);
 372
 373         /* cache head and tail of queue */
 374         head = ch->ch_r_head & RQUEUEMASK;
 375         tail = ch->ch_r_tail & RQUEUEMASK;
 376
 377         /* Get our cached LSR */
 378         linestatus = ch->ch_cached_lsr;
 379         ch->ch_cached_lsr = 0;
 380
 381         /* Store how much space we have left in the queue */
 382         qleft = tail - head - 1;
 383         if (qleft < 0)
 384                 qleft += RQUEUEMASK + 1;
 385
 386         /*
 387          * Create a mask to determine whether we should
 388          * insert the character (if any) into our queue.
 389          */
 390         if (ch->ch_c_iflag & IGNBRK)
 391                 error_mask |= UART_LSR_BI;
 392
 393         while (1) {
 394                 /*
 395                  * Grab the linestatus register, we need to
 396                  * check to see if there is any data to read
 397                  */
 398                 linestatus = readb(&ch->ch_cls_uart->lsr);
 399
 400                 /* Break out if there is no data to fetch */
 401                 if (!(linestatus & UART_LSR_DR))
 402                         break;
 403
 404                 /*
 405                  * Discard character if we are ignoring the error mask
 406                  * which in this case is the break signal.
 407                  */
 408                 if (linestatus & error_mask)  {
 409                         u8 discard;
 410
 411                         linestatus = 0;
 412                         discard = readb(&ch->ch_cls_uart->txrx);
 413                         continue;
 414                 }
 415
 416                 /*
 417                  * If our queue is full, we have no choice but to drop some
 418                  * data. The assumption is that HWFLOW or SWFLOW should have
 419                  * stopped things way way before we got to this point.
 420                  *
 421                  * I decided that I wanted to ditch the oldest data first,
 422                  * I hope thats okay with everyone? Yes? Good.
 423                  */
 424                 while (qleft < 1) {
 425                         tail = (tail + 1) & RQUEUEMASK;
 426                         ch->ch_r_tail = tail;
 427                         ch->ch_err_overrun++;
 428                         qleft++;
 429                 }
 430
 431                 ch->ch_equeue[head] = linestatus & (UART_LSR_BI | UART_LSR_PE
 432                                                                  | UART_LSR_FE);
 433                 ch->ch_rqueue[head] = readb(&ch->ch_cls_uart->txrx);
 434
 435                 qleft--;
 436
 437                 if (ch->ch_equeue[head] & UART_LSR_PE)
 438                         ch->ch_err_parity++;
 439                 if (ch->ch_equeue[head] & UART_LSR_BI)
 440                         ch->ch_err_break++;
 441                 if (ch->ch_equeue[head] & UART_LSR_FE)
 442                         ch->ch_err_frame++;
 443
 444                 /* Add to, and flip head if needed */
 445                 head = (head + 1) & RQUEUEMASK;
 446                 ch->ch_rxcount++;
 447         }
 448
 449         /*
 450          * Write new final heads to channel structure.
 451          */
 452         ch->ch_r_head = head & RQUEUEMASK;
 453         ch->ch_e_head = head & EQUEUEMASK;
 454
 455         spin_unlock_irqrestore(&ch->ch_lock, flags);
 456 }
 457
 458 static void cls_copy_data_from_queue_to_uart(struct jsm_channel *ch)
 459 {
 460         u16 tail;
 461         int n;
 462         int qlen;
 463         u32 len_written = 0;
 464         struct circ_buf *circ;
 465
 466         if (!ch)
 467                 return;
 468
 469         circ = &ch->uart_port.state->xmit;
 470
 471         /* No data to write to the UART */
 472         if (uart_circ_empty(circ))
 473                 return;
 474
 475         /* If port is "stopped", don't send any data to the UART */
 476         if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
 477                 return;
 478
 479         /* We have to do it this way, because of the EXAR TXFIFO count bug. */
 480         if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
 481                 return;
 482
 483         n = 32;
 484
 485         /* cache tail of queue */
 486         tail = circ->tail & (UART_XMIT_SIZE - 1);
 487         qlen = uart_circ_chars_pending(circ);
 488
 489         /* Find minimum of the FIFO space, versus queue length */
 490         n = min(n, qlen);
 491
 492         while (n > 0) {
 493                 writeb(circ->buf[tail], &ch->ch_cls_uart->txrx);
 494                 tail = (tail + 1) & (UART_XMIT_SIZE - 1);
 495                 n--;
 496                 ch->ch_txcount++;
 497                 len_written++;
 498         }
 499
 500         /* Update the final tail */
 501         circ->tail = tail & (UART_XMIT_SIZE - 1);
 502
 503         if (len_written > ch->ch_t_tlevel)
 504                 ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 505
 506         if (uart_circ_empty(circ))
 507                 uart_write_wakeup(&ch->uart_port);
 508 }
 509
 510 static void cls_parse_modem(struct jsm_channel *ch, u8 signals)
 511 {
 512         u8 msignals = signals;
 513
 514         jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
 515                 "neo_parse_modem: port: %d msignals: %x\n",
 516                 ch->ch_portnum, msignals);
 517
 518         /*
 519          * Scrub off lower bits.
 520          * They signify delta's, which I don't care about
 521          * Keep DDCD and DDSR though
 522          */
 523         msignals &= 0xf8;
 524
 525         if (msignals & UART_MSR_DDCD)
 526                 uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
 527         if (msignals & UART_MSR_DDSR)
 528                 uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_CTS);
 529
 530         if (msignals & UART_MSR_DCD)
 531                 ch->ch_mistat |= UART_MSR_DCD;
 532         else
 533                 ch->ch_mistat &= ~UART_MSR_DCD;
 534
 535         if (msignals & UART_MSR_DSR)
 536                 ch->ch_mistat |= UART_MSR_DSR;
 537         else
 538                 ch->ch_mistat &= ~UART_MSR_DSR;
 539
 540         if (msignals & UART_MSR_RI)
 541                 ch->ch_mistat |= UART_MSR_RI;
 542         else
 543                 ch->ch_mistat &= ~UART_MSR_RI;
 544
 545         if (msignals & UART_MSR_CTS)
 546                 ch->ch_mistat |= UART_MSR_CTS;
 547         else
 548                 ch->ch_mistat &= ~UART_MSR_CTS;
 549
 550         jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
 551                 "Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
 552                 ch->ch_portnum,
 553                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
 554                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
 555                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
 556                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
 557                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
 558                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
 559 }
 560
 561 /* Parse the ISR register for the specific port */
 562 static inline void cls_parse_isr(struct jsm_board *brd, uint port)
 563 {
 564         struct jsm_channel *ch;
 565         u8 isr = 0;
 566         unsigned long flags;
 567
 568         /*
 569          * No need to verify board pointer, it was already
 570          * verified in the interrupt routine.
 571          */
 572
 573         if (port >= brd->nasync)
 574                 return;
 575
 576         ch = brd->channels[port];
 577         if (!ch)
 578                 return;
 579
 580         /* Here we try to figure out what caused the interrupt to happen */
 581         while (1) {
 582                 isr = readb(&ch->ch_cls_uart->isr_fcr);
 583
 584                 /* Bail if no pending interrupt on port */
 585                 if (isr & UART_IIR_NO_INT)
 586                         break;
 587
 588                 /* Receive Interrupt pending */
 589                 if (isr & (UART_IIR_RDI | UART_IIR_RDI_TIMEOUT)) {
 590                         /* Read data from uart -> queue */
 591                         cls_copy_data_from_uart_to_queue(ch);
 592                         jsm_check_queue_flow_control(ch);
 593                 }
 594
 595                 /* Transmit Hold register empty pending */
 596                 if (isr & UART_IIR_THRI) {
 597                         /* Transfer data (if any) from Write Queue -> UART. */
 598                         spin_lock_irqsave(&ch->ch_lock, flags);
 599                         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 600                         spin_unlock_irqrestore(&ch->ch_lock, flags);
 601                         cls_copy_data_from_queue_to_uart(ch);
 602                 }
 603
 604                 /*
 605                  * CTS/RTS change of state:
 606                  * Don't need to do anything, the cls_parse_modem
 607                  * below will grab the updated modem signals.
 608                  */
 609
 610                 /* Parse any modem signal changes */
 611                 cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
 612         }
 613 }
 614
 615 /* Channel lock MUST be held before calling this function! */
 616 static void cls_flush_uart_write(struct jsm_channel *ch)
 617 {
 618         u8 tmp = 0;
 619         u8 i = 0;
 620
 621         if (!ch)
 622                 return;
 623
 624         writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT),
 625                                                 &ch->ch_cls_uart->isr_fcr);
 626
 627         for (i = 0; i < 10; i++) {
 628                 /* Check to see if the UART feels it completely flushed FIFO */
 629                 tmp = readb(&ch->ch_cls_uart->isr_fcr);
 630                 if (tmp & UART_FCR_CLEAR_XMIT) {
 631                         jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
 632                                 "Still flushing TX UART... i: %d\n", i);
 633                         udelay(10);
 634                 } else
 635                         break;
 636         }
 637
 638         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 639 }
 640
 641 /* Channel lock MUST be held before calling this function! */
 642 static void cls_flush_uart_read(struct jsm_channel *ch)
 643 {
 644         if (!ch)
 645                 return;
 646
 647         /*
 648          * For complete POSIX compatibility, we should be purging the
 649          * read FIFO in the UART here.
 650          *
 651          * However, clearing the read FIFO (UART_FCR_CLEAR_RCVR) also
 652          * incorrectly flushes write data as well as just basically trashing the
 653          * FIFO.
 654          *
 655          * Presumably, this is a bug in this UART.
 656          */
 657
 658         udelay(10);
 659 }
 660
 661 static void cls_send_start_character(struct jsm_channel *ch)
 662 {
 663         if (!ch)
 664                 return;
 665
 666         if (ch->ch_startc != __DISABLED_CHAR) {
 667                 ch->ch_xon_sends++;
 668                 writeb(ch->ch_startc, &ch->ch_cls_uart->txrx);
 669         }
 670 }
 671
 672 static void cls_send_stop_character(struct jsm_channel *ch)
 673 {
 674         if (!ch)
 675                 return;
 676
 677         if (ch->ch_stopc != __DISABLED_CHAR) {
 678                 ch->ch_xoff_sends++;
 679                 writeb(ch->ch_stopc, &ch->ch_cls_uart->txrx);
 680         }
 681 }
 682
 683 /*
 684  * cls_param()
 685  * Send any/all changes to the line to the UART.
 686  */
 687 static void cls_param(struct jsm_channel *ch)
 688 {
 689         u8 lcr = 0;
 690         u8 uart_lcr = 0;
 691         u8 ier = 0;
 692         u32 baud = 9600;
 693         int quot = 0;
 694         struct jsm_board *bd;
 695         int i;
 696         unsigned int cflag;
 697
 698         bd = ch->ch_bd;
 699         if (!bd)
 700                 return;
 701
 702         /*
 703          * If baud rate is zero, flush queues, and set mval to drop DTR.
 704          */
 705         if ((ch->ch_c_cflag & (CBAUD)) == 0) {
 706                 ch->ch_r_head = 0;
 707                 ch->ch_r_tail = 0;
 708                 ch->ch_e_head = 0;
 709                 ch->ch_e_tail = 0;
 710
 711                 cls_flush_uart_write(ch);
 712                 cls_flush_uart_read(ch);
 713
 714                 /* The baudrate is B0 so all modem lines are to be dropped. */
 715                 ch->ch_flags |= (CH_BAUD0);
 716                 ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
 717                 cls_assert_modem_signals(ch);
 718                 return;
 719         }
 720
 721         cflag = C_BAUD(ch->uart_port.state->port.tty);
 722         baud = 9600;
 723         for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
 724                 if (baud_rates[i].cflag == cflag) {
 725                         baud = baud_rates[i].rate;
 726                         break;
 727                 }
 728         }
 729
 730         if (ch->ch_flags & CH_BAUD0)
 731                 ch->ch_flags &= ~(CH_BAUD0);
 732
 733         if (ch->ch_c_cflag & PARENB)
 734                 lcr |= UART_LCR_PARITY;
 735
 736         if (!(ch->ch_c_cflag & PARODD))
 737                 lcr |= UART_LCR_EPAR;
 738
 739         /*
 740          * Not all platforms support mark/space parity,
 741          * so this will hide behind an ifdef.
 742          */
 743 #ifdef CMSPAR
 744         if (ch->ch_c_cflag & CMSPAR)
 745                 lcr |= UART_LCR_SPAR;
 746 #endif
 747
 748         if (ch->ch_c_cflag & CSTOPB)
 749                 lcr |= UART_LCR_STOP;
 750
 751         switch (ch->ch_c_cflag & CSIZE) {
 752         case CS5:
 753                 lcr |= UART_LCR_WLEN5;
 754                 break;
 755         case CS6:
 756                 lcr |= UART_LCR_WLEN6;
 757                 break;
 758         case CS7:
 759                 lcr |= UART_LCR_WLEN7;
 760                 break;
 761         case CS8:
 762         default:
 763                 lcr |= UART_LCR_WLEN8;
 764                 break;
 765         }
 766
 767         ier = readb(&ch->ch_cls_uart->ier);
 768         uart_lcr = readb(&ch->ch_cls_uart->lcr);
 769
 770         quot = ch->ch_bd->bd_dividend / baud;
 771
 772         if (quot != 0) {
 773                 writeb(UART_LCR_DLAB, &ch->ch_cls_uart->lcr);
 774                 writeb((quot & 0xff), &ch->ch_cls_uart->txrx);
 775                 writeb((quot >> 8), &ch->ch_cls_uart->ier);
 776                 writeb(lcr, &ch->ch_cls_uart->lcr);
 777         }
 778
 779         if (uart_lcr != lcr)
 780                 writeb(lcr, &ch->ch_cls_uart->lcr);
 781
 782         if (ch->ch_c_cflag & CREAD)
 783                 ier |= (UART_IER_RDI | UART_IER_RLSI);
 784
 785         ier |= (UART_IER_THRI | UART_IER_MSI);
 786
 787         writeb(ier, &ch->ch_cls_uart->ier);
 788
 789         if (ch->ch_c_cflag & CRTSCTS)
 790                 cls_set_cts_flow_control(ch);
 791         else if (ch->ch_c_iflag & IXON) {
 792                 /*
 793                  * If start/stop is set to disable,
 794                  * then we should disable flow control.
 795                  */
 796                 if ((ch->ch_startc == __DISABLED_CHAR) ||
 797                         (ch->ch_stopc == __DISABLED_CHAR))
 798                         cls_set_no_output_flow_control(ch);
 799                 else
 800                         cls_set_ixon_flow_control(ch);
 801         } else
 802                 cls_set_no_output_flow_control(ch);
 803
 804         if (ch->ch_c_cflag & CRTSCTS)
 805                 cls_set_rts_flow_control(ch);
 806         else if (ch->ch_c_iflag & IXOFF) {
 807                 /*
 808                  * If start/stop is set to disable,
 809                  * then we should disable flow control.
 810                  */
 811                 if ((ch->ch_startc == __DISABLED_CHAR) ||
 812                         (ch->ch_stopc == __DISABLED_CHAR))
 813                         cls_set_no_input_flow_control(ch);
 814                 else
 815                         cls_set_ixoff_flow_control(ch);
 816         } else
 817                 cls_set_no_input_flow_control(ch);
 818
 819         cls_assert_modem_signals(ch);
 820
 821         /* get current status of the modem signals now */
 822         cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
 823 }
 824
 825 /*
 826  * cls_intr()
 827  *
 828  * Classic specific interrupt handler.
 829  */
 830 static irqreturn_t cls_intr(int irq, void *voidbrd)
 831 {
 832         struct jsm_board *brd = voidbrd;
 833         unsigned long lock_flags;
 834         unsigned char uart_poll;
 835         uint i = 0;
 836
 837         /* Lock out the slow poller from running on this board. */
 838         spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
 839
 840         /*
 841          * Check the board's global interrupt offset to see if we
 842          * acctually do have an interrupt pending on us.
 843          */
 844         uart_poll = readb(brd->re_map_membase + UART_CLASSIC_POLL_ADDR_OFFSET);
 845
 846         jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
 847                 __FILE__, __LINE__, uart_poll);
 848
 849         if (!uart_poll) {
 850                 jsm_dbg(INTR, &brd->pci_dev,
 851                         "Kernel interrupted to me, but no pending interrupts...\n");
 852                 spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
 853                 return IRQ_NONE;
 854         }
 855
 856         /* At this point, we have at least SOMETHING to service, dig further. */
 857
 858         /* Parse each port to find out what caused the interrupt */
 859         for (i = 0; i < brd->nasync; i++)
 860                 cls_parse_isr(brd, i);
 861
 862         spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
 863
 864         return IRQ_HANDLED;
 865 }
 866
 867 /* Inits UART */
 868 static void cls_uart_init(struct jsm_channel *ch)
 869 {
 870         unsigned char lcrb = readb(&ch->ch_cls_uart->lcr);
 871         unsigned char isr_fcr = 0;
 872
 873         writeb(0, &ch->ch_cls_uart->ier);
 874
 875         /*
 876          * The Enhanced Register Set may only be accessed when
 877          * the Line Control Register is set to 0xBFh.
 878          */
 879         writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
 880
 881         isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
 882
 883         /* Turn on Enhanced/Extended controls */
 884         isr_fcr |= (UART_EXAR654_EFR_ECB);
 885
 886         writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
 887
 888         /* Write old LCR value back out, which turns enhanced access off */
 889         writeb(lcrb, &ch->ch_cls_uart->lcr);
 890
 891         /* Clear out UART and FIFO */
 892         readb(&ch->ch_cls_uart->txrx);
 893
 894         writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT),
 895                                                  &ch->ch_cls_uart->isr_fcr);
 896         udelay(10);
 897
 898         ch->ch_flags |= (CH_FIFO_ENABLED | CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 899
 900         readb(&ch->ch_cls_uart->lsr);
 901         readb(&ch->ch_cls_uart->msr);
 902 }
 903
 904 /*
 905  * Turns off UART.
 906  */
 907 static void cls_uart_off(struct jsm_channel *ch)
 908 {
 909         /* Stop all interrupts from accurring. */
 910         writeb(0, &ch->ch_cls_uart->ier);
 911 }
 912
 913 /*
 914  * cls_get_uarts_bytes_left.
 915  * Returns 0 is nothing left in the FIFO, returns 1 otherwise.
 916  *
 917  * The channel lock MUST be held by the calling function.
 918  */
 919 static u32 cls_get_uart_bytes_left(struct jsm_channel *ch)
 920 {
 921         u8 left = 0;
 922         u8 lsr = readb(&ch->ch_cls_uart->lsr);
 923
 924         /* Determine whether the Transmitter is empty or not */
 925         if (!(lsr & UART_LSR_TEMT))
 926                 left = 1;
 927         else {
 928                 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 929                 left = 0;
 930         }
 931
 932         return left;
 933 }
 934
 935 /*
 936  * cls_send_break.
 937  * Starts sending a break thru the UART.
 938  *
 939  * The channel lock MUST be held by the calling function.
 940  */
 941 static void cls_send_break(struct jsm_channel *ch)
 942 {
 943         /* Tell the UART to start sending the break */
 944         if (!(ch->ch_flags & CH_BREAK_SENDING)) {
 945                 u8 temp = readb(&ch->ch_cls_uart->lcr);
 946
 947                 writeb((temp | UART_LCR_SBC), &ch->ch_cls_uart->lcr);
 948                 ch->ch_flags |= (CH_BREAK_SENDING);
 949         }
 950 }
 951
 952 /*
 953  * cls_send_immediate_char.
 954  * Sends a specific character as soon as possible to the UART,
 955  * jumping over any bytes that might be in the write queue.
 956  *
 957  * The channel lock MUST be held by the calling function.
 958  */
 959 static void cls_send_immediate_char(struct jsm_channel *ch, unsigned char c)
 960 {
 961         writeb(c, &ch->ch_cls_uart->txrx);
 962 }
 963
 964 struct board_ops jsm_cls_ops = {
 965         .intr =                         cls_intr,
 966         .uart_init =                    cls_uart_init,
 967         .uart_off =                     cls_uart_off,
 968         .param =                        cls_param,
 969         .assert_modem_signals =         cls_assert_modem_signals,
 970         .flush_uart_write =             cls_flush_uart_write,
 971         .flush_uart_read =              cls_flush_uart_read,
 972         .disable_receiver =             cls_disable_receiver,
 973         .enable_receiver =              cls_enable_receiver,
 974         .send_break =                   cls_send_break,
 975         .clear_break =                  cls_clear_break,
 976         .send_start_character =         cls_send_start_character,
 977         .send_stop_character =          cls_send_stop_character,
 978         .copy_data_from_queue_to_uart = cls_copy_data_from_queue_to_uart,
 979         .get_uart_bytes_left =          cls_get_uart_bytes_left,
 980         .send_immediate_char =          cls_send_immediate_char
 981 };
 982