drivers/tty/serial/jsm/jsm_neo.c

   1 /************************************************************************
   2  * Copyright 2003 Digi International (www.digi.com)
   3  *
   4  * Copyright (C) 2004 IBM Corporation. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
  13  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  14  * PURPOSE.  See the GNU General Public License for more details.
  15  *
  16  * Contact Information:
  17  * Scott H Kilau <Scott_Kilau@digi.com>
  18  * Wendy Xiong   <wendyx@us.ibm.com>
  19  *
  20  ***********************************************************************/
  21 #include <linux/delay.h>        /* For udelay */
  22 #include <linux/serial_reg.h>   /* For the various UART offsets */
  23 #include <linux/tty.h>
  24 #include <linux/pci.h>
  25 #include <asm/io.h>
  26
  27 #include "jsm.h"                /* Driver main header file */
  28
  29 static u32 jsm_offset_table[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
  30
  31 /*
  32  * This function allows calls to ensure that all outstanding
  33  * PCI writes have been completed, by doing a PCI read against
  34  * a non-destructive, read-only location on the Neo card.
  35  *
  36  * In this case, we are reading the DVID (Read-only Device Identification)
  37  * value of the Neo card.
  38  */
  39 static inline void neo_pci_posting_flush(struct jsm_board *bd)
  40 {
  41       readb(bd->re_map_membase + 0x8D);
  42 }
  43
  44 static void neo_set_cts_flow_control(struct jsm_channel *ch)
  45 {
  46         u8 ier, efr;
  47         ier = readb(&ch->ch_neo_uart->ier);
  48         efr = readb(&ch->ch_neo_uart->efr);
  49
  50         jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting CTSFLOW\n");
  51
  52         /* Turn on auto CTS flow control */
  53         ier |= (UART_17158_IER_CTSDSR);
  54         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_CTSDSR);
  55
  56         /* Turn off auto Xon flow control */
  57         efr &= ~(UART_17158_EFR_IXON);
  58
  59         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
  60         writeb(0, &ch->ch_neo_uart->efr);
  61
  62         /* Turn on UART enhanced bits */
  63         writeb(efr, &ch->ch_neo_uart->efr);
  64
  65         /* Turn on table D, with 8 char hi/low watermarks */
  66         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
  67
  68         /* Feed the UART our trigger levels */
  69         writeb(8, &ch->ch_neo_uart->tfifo);
  70         ch->ch_t_tlevel = 8;
  71
  72         writeb(ier, &ch->ch_neo_uart->ier);
  73 }
  74
  75 static void neo_set_rts_flow_control(struct jsm_channel *ch)
  76 {
  77         u8 ier, efr;
  78         ier = readb(&ch->ch_neo_uart->ier);
  79         efr = readb(&ch->ch_neo_uart->efr);
  80
  81         jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting RTSFLOW\n");
  82
  83         /* Turn on auto RTS flow control */
  84         ier |= (UART_17158_IER_RTSDTR);
  85         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_RTSDTR);
  86
  87         /* Turn off auto Xoff flow control */
  88         ier &= ~(UART_17158_IER_XOFF);
  89         efr &= ~(UART_17158_EFR_IXOFF);
  90
  91         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
  92         writeb(0, &ch->ch_neo_uart->efr);
  93
  94         /* Turn on UART enhanced bits */
  95         writeb(efr, &ch->ch_neo_uart->efr);
  96
  97         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
  98         ch->ch_r_watermark = 4;
  99
 100         writeb(56, &ch->ch_neo_uart->rfifo);
 101         ch->ch_r_tlevel = 56;
 102
 103         writeb(ier, &ch->ch_neo_uart->ier);
 104
 105         /*
 106          * From the Neo UART spec sheet:
 107          * The auto RTS/DTR function must be started by asserting
 108          * RTS/DTR# output pin (MCR bit-0 or 1 to logic 1 after
 109          * it is enabled.
 110          */
 111         ch->ch_mostat |= (UART_MCR_RTS);
 112 }
 113
 114
 115 static void neo_set_ixon_flow_control(struct jsm_channel *ch)
 116 {
 117         u8 ier, efr;
 118         ier = readb(&ch->ch_neo_uart->ier);
 119         efr = readb(&ch->ch_neo_uart->efr);
 120
 121         jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting IXON FLOW\n");
 122
 123         /* Turn off auto CTS flow control */
 124         ier &= ~(UART_17158_IER_CTSDSR);
 125         efr &= ~(UART_17158_EFR_CTSDSR);
 126
 127         /* Turn on auto Xon flow control */
 128         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXON);
 129
 130         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 131         writeb(0, &ch->ch_neo_uart->efr);
 132
 133         /* Turn on UART enhanced bits */
 134         writeb(efr, &ch->ch_neo_uart->efr);
 135
 136         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 137         ch->ch_r_watermark = 4;
 138
 139         writeb(32, &ch->ch_neo_uart->rfifo);
 140         ch->ch_r_tlevel = 32;
 141
 142         /* Tell UART what start/stop chars it should be looking for */
 143         writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
 144         writeb(0, &ch->ch_neo_uart->xonchar2);
 145
 146         writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
 147         writeb(0, &ch->ch_neo_uart->xoffchar2);
 148
 149         writeb(ier, &ch->ch_neo_uart->ier);
 150 }
 151
 152 static void neo_set_ixoff_flow_control(struct jsm_channel *ch)
 153 {
 154         u8 ier, efr;
 155         ier = readb(&ch->ch_neo_uart->ier);
 156         efr = readb(&ch->ch_neo_uart->efr);
 157
 158         jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Setting IXOFF FLOW\n");
 159
 160         /* Turn off auto RTS flow control */
 161         ier &= ~(UART_17158_IER_RTSDTR);
 162         efr &= ~(UART_17158_EFR_RTSDTR);
 163
 164         /* Turn on auto Xoff flow control */
 165         ier |= (UART_17158_IER_XOFF);
 166         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
 167
 168         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 169         writeb(0, &ch->ch_neo_uart->efr);
 170
 171         /* Turn on UART enhanced bits */
 172         writeb(efr, &ch->ch_neo_uart->efr);
 173
 174         /* Turn on table D, with 8 char hi/low watermarks */
 175         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 176
 177         writeb(8, &ch->ch_neo_uart->tfifo);
 178         ch->ch_t_tlevel = 8;
 179
 180         /* Tell UART what start/stop chars it should be looking for */
 181         writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
 182         writeb(0, &ch->ch_neo_uart->xonchar2);
 183
 184         writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
 185         writeb(0, &ch->ch_neo_uart->xoffchar2);
 186
 187         writeb(ier, &ch->ch_neo_uart->ier);
 188 }
 189
 190 static void neo_set_no_input_flow_control(struct jsm_channel *ch)
 191 {
 192         u8 ier, efr;
 193         ier = readb(&ch->ch_neo_uart->ier);
 194         efr = readb(&ch->ch_neo_uart->efr);
 195
 196         jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Unsetting Input FLOW\n");
 197
 198         /* Turn off auto RTS flow control */
 199         ier &= ~(UART_17158_IER_RTSDTR);
 200         efr &= ~(UART_17158_EFR_RTSDTR);
 201
 202         /* Turn off auto Xoff flow control */
 203         ier &= ~(UART_17158_IER_XOFF);
 204         if (ch->ch_c_iflag & IXON)
 205                 efr &= ~(UART_17158_EFR_IXOFF);
 206         else
 207                 efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
 208
 209         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 210         writeb(0, &ch->ch_neo_uart->efr);
 211
 212         /* Turn on UART enhanced bits */
 213         writeb(efr, &ch->ch_neo_uart->efr);
 214
 215         /* Turn on table D, with 8 char hi/low watermarks */
 216         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 217
 218         ch->ch_r_watermark = 0;
 219
 220         writeb(16, &ch->ch_neo_uart->tfifo);
 221         ch->ch_t_tlevel = 16;
 222
 223         writeb(16, &ch->ch_neo_uart->rfifo);
 224         ch->ch_r_tlevel = 16;
 225
 226         writeb(ier, &ch->ch_neo_uart->ier);
 227 }
 228
 229 static void neo_set_no_output_flow_control(struct jsm_channel *ch)
 230 {
 231         u8 ier, efr;
 232         ier = readb(&ch->ch_neo_uart->ier);
 233         efr = readb(&ch->ch_neo_uart->efr);
 234
 235         jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "Unsetting Output FLOW\n");
 236
 237         /* Turn off auto CTS flow control */
 238         ier &= ~(UART_17158_IER_CTSDSR);
 239         efr &= ~(UART_17158_EFR_CTSDSR);
 240
 241         /* Turn off auto Xon flow control */
 242         if (ch->ch_c_iflag & IXOFF)
 243                 efr &= ~(UART_17158_EFR_IXON);
 244         else
 245                 efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXON);
 246
 247         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 248         writeb(0, &ch->ch_neo_uart->efr);
 249
 250         /* Turn on UART enhanced bits */
 251         writeb(efr, &ch->ch_neo_uart->efr);
 252
 253         /* Turn on table D, with 8 char hi/low watermarks */
 254         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 255
 256         ch->ch_r_watermark = 0;
 257
 258         writeb(16, &ch->ch_neo_uart->tfifo);
 259         ch->ch_t_tlevel = 16;
 260
 261         writeb(16, &ch->ch_neo_uart->rfifo);
 262         ch->ch_r_tlevel = 16;
 263
 264         writeb(ier, &ch->ch_neo_uart->ier);
 265 }
 266
 267 static inline void neo_set_new_start_stop_chars(struct jsm_channel *ch)
 268 {
 269
 270         /* if hardware flow control is set, then skip this whole thing */
 271         if (ch->ch_c_cflag & CRTSCTS)
 272                 return;
 273
 274         jsm_dbg(PARAM, &ch->ch_bd->pci_dev, "start\n");
 275
 276         /* Tell UART what start/stop chars it should be looking for */
 277         writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
 278         writeb(0, &ch->ch_neo_uart->xonchar2);
 279
 280         writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
 281         writeb(0, &ch->ch_neo_uart->xoffchar2);
 282 }
 283
 284 static void neo_copy_data_from_uart_to_queue(struct jsm_channel *ch)
 285 {
 286         int qleft = 0;
 287         u8 linestatus = 0;
 288         u8 error_mask = 0;
 289         int n = 0;
 290         int total = 0;
 291         u16 head;
 292         u16 tail;
 293
 294         if (!ch)
 295                 return;
 296
 297         /* cache head and tail of queue */
 298         head = ch->ch_r_head & RQUEUEMASK;
 299         tail = ch->ch_r_tail & RQUEUEMASK;
 300
 301         /* Get our cached LSR */
 302         linestatus = ch->ch_cached_lsr;
 303         ch->ch_cached_lsr = 0;
 304
 305         /* Store how much space we have left in the queue */
 306         if ((qleft = tail - head - 1) < 0)
 307                 qleft += RQUEUEMASK + 1;
 308
 309         /*
 310          * If the UART is not in FIFO mode, force the FIFO copy to
 311          * NOT be run, by setting total to 0.
 312          *
 313          * On the other hand, if the UART IS in FIFO mode, then ask
 314          * the UART to give us an approximation of data it has RX'ed.
 315          */
 316         if (!(ch->ch_flags & CH_FIFO_ENABLED))
 317                 total = 0;
 318         else {
 319                 total = readb(&ch->ch_neo_uart->rfifo);
 320
 321                 /*
 322                  * EXAR chip bug - RX FIFO COUNT - Fudge factor.
 323                  *
 324                  * This resolves a problem/bug with the Exar chip that sometimes
 325                  * returns a bogus value in the rfifo register.
 326                  * The count can be any where from 0-3 bytes "off".
 327                  * Bizarre, but true.
 328                  */
 329                 total -= 3;
 330         }
 331
 332         /*
 333          * Finally, bound the copy to make sure we don't overflow
 334          * our own queue...
 335          * The byte by byte copy loop below this loop this will
 336          * deal with the queue overflow possibility.
 337          */
 338         total = min(total, qleft);
 339
 340         while (total > 0) {
 341                 /*
 342                  * Grab the linestatus register, we need to check
 343                  * to see if there are any errors in the FIFO.
 344                  */
 345                 linestatus = readb(&ch->ch_neo_uart->lsr);
 346
 347                 /*
 348                  * Break out if there is a FIFO error somewhere.
 349                  * This will allow us to go byte by byte down below,
 350                  * finding the exact location of the error.
 351                  */
 352                 if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
 353                         break;
 354
 355                 /* Make sure we don't go over the end of our queue */
 356                 n = min(((u32) total), (RQUEUESIZE - (u32) head));
 357
 358                 /*
 359                  * Cut down n even further if needed, this is to fix
 360                  * a problem with memcpy_fromio() with the Neo on the
 361                  * IBM pSeries platform.
 362                  * 15 bytes max appears to be the magic number.
 363                  */
 364                 n = min((u32) n, (u32) 12);
 365
 366                 /*
 367                  * Since we are grabbing the linestatus register, which
 368                  * will reset some bits after our read, we need to ensure
 369                  * we don't miss our TX FIFO emptys.
 370                  */
 371                 if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
 372                         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 373
 374                 linestatus = 0;
 375
 376                 /* Copy data from uart to the queue */
 377                 memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, n);
 378                 /*
 379                  * Since RX_FIFO_DATA_ERROR was 0, we are guaranteed
 380                  * that all the data currently in the FIFO is free of
 381                  * breaks and parity/frame/orun errors.
 382                  */
 383                 memset(ch->ch_equeue + head, 0, n);
 384
 385                 /* Add to and flip head if needed */
 386                 head = (head + n) & RQUEUEMASK;
 387                 total -= n;
 388                 qleft -= n;
 389                 ch->ch_rxcount += n;
 390         }
 391
 392         /*
 393          * Create a mask to determine whether we should
 394          * insert the character (if any) into our queue.
 395          */
 396         if (ch->ch_c_iflag & IGNBRK)
 397                 error_mask |= UART_LSR_BI;
 398
 399         /*
 400          * Now cleanup any leftover bytes still in the UART.
 401          * Also deal with any possible queue overflow here as well.
 402          */
 403         while (1) {
 404
 405                 /*
 406                  * Its possible we have a linestatus from the loop above
 407                  * this, so we "OR" on any extra bits.
 408                  */
 409                 linestatus |= readb(&ch->ch_neo_uart->lsr);
 410
 411                 /*
 412                  * If the chip tells us there is no more data pending to
 413                  * be read, we can then leave.
 414                  * But before we do, cache the linestatus, just in case.
 415                  */
 416                 if (!(linestatus & UART_LSR_DR)) {
 417                         ch->ch_cached_lsr = linestatus;
 418                         break;
 419                 }
 420
 421                 /* No need to store this bit */
 422                 linestatus &= ~UART_LSR_DR;
 423
 424                 /*
 425                  * Since we are grabbing the linestatus register, which
 426                  * will reset some bits after our read, we need to ensure
 427                  * we don't miss our TX FIFO emptys.
 428                  */
 429                 if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
 430                         linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
 431                         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 432                 }
 433
 434                 /*
 435                  * Discard character if we are ignoring the error mask.
 436                  */
 437                 if (linestatus & error_mask) {
 438                         u8 discard;
 439                         linestatus = 0;
 440                         memcpy_fromio(&discard, &ch->ch_neo_uart->txrxburst, 1);
 441                         continue;
 442                 }
 443
 444                 /*
 445                  * If our queue is full, we have no choice but to drop some data.
 446                  * The assumption is that HWFLOW or SWFLOW should have stopped
 447                  * things way way before we got to this point.
 448                  *
 449                  * I decided that I wanted to ditch the oldest data first,
 450                  * I hope thats okay with everyone? Yes? Good.
 451                  */
 452                 while (qleft < 1) {
 453                         jsm_dbg(READ, &ch->ch_bd->pci_dev,
 454                                 "Queue full, dropping DATA:%x LSR:%x\n",
 455                                 ch->ch_rqueue[tail], ch->ch_equeue[tail]);
 456
 457                         ch->ch_r_tail = tail = (tail + 1) & RQUEUEMASK;
 458                         ch->ch_err_overrun++;
 459                         qleft++;
 460                 }
 461
 462                 memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, 1);
 463                 ch->ch_equeue[head] = (u8) linestatus;
 464
 465                 jsm_dbg(READ, &ch->ch_bd->pci_dev, "DATA/LSR pair: %x %x\n",
 466                         ch->ch_rqueue[head], ch->ch_equeue[head]);
 467
 468                 /* Ditch any remaining linestatus value. */
 469                 linestatus = 0;
 470
 471                 /* Add to and flip head if needed */
 472                 head = (head + 1) & RQUEUEMASK;
 473
 474                 qleft--;
 475                 ch->ch_rxcount++;
 476         }
 477
 478         /*
 479          * Write new final heads to channel structure.
 480          */
 481         ch->ch_r_head = head & RQUEUEMASK;
 482         ch->ch_e_head = head & EQUEUEMASK;
 483         jsm_input(ch);
 484 }
 485
 486 static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
 487 {
 488         u16 head;
 489         u16 tail;
 490         int n;
 491         int s;
 492         int qlen;
 493         u32 len_written = 0;
 494         struct circ_buf *circ;
 495
 496         if (!ch)
 497                 return;
 498
 499         circ = &ch->uart_port.state->xmit;
 500
 501         /* No data to write to the UART */
 502         if (uart_circ_empty(circ))
 503                 return;
 504
 505         /* If port is "stopped", don't send any data to the UART */
 506         if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
 507                 return;
 508         /*
 509          * If FIFOs are disabled. Send data directly to txrx register
 510          */
 511         if (!(ch->ch_flags & CH_FIFO_ENABLED)) {
 512                 u8 lsrbits = readb(&ch->ch_neo_uart->lsr);
 513
 514                 ch->ch_cached_lsr |= lsrbits;
 515                 if (ch->ch_cached_lsr & UART_LSR_THRE) {
 516                         ch->ch_cached_lsr &= ~(UART_LSR_THRE);
 517
 518                         writeb(circ->buf[circ->tail], &ch->ch_neo_uart->txrx);
 519                         jsm_dbg(WRITE, &ch->ch_bd->pci_dev,
 520                                 "Tx data: %x\n", circ->buf[circ->tail]);
 521                         circ->tail = (circ->tail + 1) & (UART_XMIT_SIZE - 1);
 522                         ch->ch_txcount++;
 523                 }
 524                 return;
 525         }
 526
 527         /*
 528          * We have to do it this way, because of the EXAR TXFIFO count bug.
 529          */
 530         if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
 531                 return;
 532
 533         n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
 534
 535         /* cache head and tail of queue */
 536         head = circ->head & (UART_XMIT_SIZE - 1);
 537         tail = circ->tail & (UART_XMIT_SIZE - 1);
 538         qlen = uart_circ_chars_pending(circ);
 539
 540         /* Find minimum of the FIFO space, versus queue length */
 541         n = min(n, qlen);
 542
 543         while (n > 0) {
 544
 545                 s = ((head >= tail) ? head : UART_XMIT_SIZE) - tail;
 546                 s = min(s, n);
 547
 548                 if (s <= 0)
 549                         break;
 550
 551                 memcpy_toio(&ch->ch_neo_uart->txrxburst, circ->buf + tail, s);
 552                 /* Add and flip queue if needed */
 553                 tail = (tail + s) & (UART_XMIT_SIZE - 1);
 554                 n -= s;
 555                 ch->ch_txcount += s;
 556                 len_written += s;
 557         }
 558
 559         /* Update the final tail */
 560         circ->tail = tail & (UART_XMIT_SIZE - 1);
 561
 562         if (len_written >= ch->ch_t_tlevel)
 563                 ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 564
 565         if (uart_circ_empty(circ))
 566                 uart_write_wakeup(&ch->uart_port);
 567 }
 568
 569 static void neo_parse_modem(struct jsm_channel *ch, u8 signals)
 570 {
 571         u8 msignals = signals;
 572
 573         jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
 574                 "neo_parse_modem: port: %d msignals: %x\n",
 575                 ch->ch_portnum, msignals);
 576
 577         /* Scrub off lower bits. They signify delta's, which I don't care about */
 578         /* Keep DDCD and DDSR though */
 579         msignals &= 0xf8;
 580
 581         if (msignals & UART_MSR_DDCD)
 582                 uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
 583         if (msignals & UART_MSR_DDSR)
 584                 uart_handle_cts_change(&ch->uart_port, msignals & UART_MSR_CTS);
 585         if (msignals & UART_MSR_DCD)
 586                 ch->ch_mistat |= UART_MSR_DCD;
 587         else
 588                 ch->ch_mistat &= ~UART_MSR_DCD;
 589
 590         if (msignals & UART_MSR_DSR)
 591                 ch->ch_mistat |= UART_MSR_DSR;
 592         else
 593                 ch->ch_mistat &= ~UART_MSR_DSR;
 594
 595         if (msignals & UART_MSR_RI)
 596                 ch->ch_mistat |= UART_MSR_RI;
 597         else
 598                 ch->ch_mistat &= ~UART_MSR_RI;
 599
 600         if (msignals & UART_MSR_CTS)
 601                 ch->ch_mistat |= UART_MSR_CTS;
 602         else
 603                 ch->ch_mistat &= ~UART_MSR_CTS;
 604
 605         jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
 606                 "Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
 607                 ch->ch_portnum,
 608                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
 609                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
 610                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
 611                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
 612                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
 613                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
 614 }
 615
 616 /* Make the UART raise any of the output signals we want up */
 617 static void neo_assert_modem_signals(struct jsm_channel *ch)
 618 {
 619         if (!ch)
 620                 return;
 621
 622         writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
 623
 624         /* flush write operation */
 625         neo_pci_posting_flush(ch->ch_bd);
 626 }
 627
 628 /*
 629  * Flush the WRITE FIFO on the Neo.
 630  *
 631  * NOTE: Channel lock MUST be held before calling this function!
 632  */
 633 static void neo_flush_uart_write(struct jsm_channel *ch)
 634 {
 635         u8 tmp = 0;
 636         int i = 0;
 637
 638         if (!ch)
 639                 return;
 640
 641         writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
 642
 643         for (i = 0; i < 10; i++) {
 644
 645                 /* Check to see if the UART feels it completely flushed the FIFO. */
 646                 tmp = readb(&ch->ch_neo_uart->isr_fcr);
 647                 if (tmp & UART_FCR_CLEAR_XMIT) {
 648                         jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
 649                                 "Still flushing TX UART... i: %d\n", i);
 650                         udelay(10);
 651                 }
 652                 else
 653                         break;
 654         }
 655
 656         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 657 }
 658
 659
 660 /*
 661  * Flush the READ FIFO on the Neo.
 662  *
 663  * NOTE: Channel lock MUST be held before calling this function!
 664  */
 665 static void neo_flush_uart_read(struct jsm_channel *ch)
 666 {
 667         u8 tmp = 0;
 668         int i = 0;
 669
 670         if (!ch)
 671                 return;
 672
 673         writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR), &ch->ch_neo_uart->isr_fcr);
 674
 675         for (i = 0; i < 10; i++) {
 676
 677                 /* Check to see if the UART feels it completely flushed the FIFO. */
 678                 tmp = readb(&ch->ch_neo_uart->isr_fcr);
 679                 if (tmp & 2) {
 680                         jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
 681                                 "Still flushing RX UART... i: %d\n", i);
 682                         udelay(10);
 683                 }
 684                 else
 685                         break;
 686         }
 687 }
 688
 689 /*
 690  * No locks are assumed to be held when calling this function.
 691  */
 692 static void neo_clear_break(struct jsm_channel *ch)
 693 {
 694         unsigned long lock_flags;
 695
 696         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 697
 698         /* Turn break off, and unset some variables */
 699         if (ch->ch_flags & CH_BREAK_SENDING) {
 700                 u8 temp = readb(&ch->ch_neo_uart->lcr);
 701                 writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
 702
 703                 ch->ch_flags &= ~(CH_BREAK_SENDING);
 704                 jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
 705                         "clear break Finishing UART_LCR_SBC! finished: %lx\n",
 706                         jiffies);
 707
 708                 /* flush write operation */
 709                 neo_pci_posting_flush(ch->ch_bd);
 710         }
 711         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 712 }
 713
 714 /*
 715  * Parse the ISR register.
 716  */
 717 static inline void neo_parse_isr(struct jsm_board *brd, u32 port)
 718 {
 719         struct jsm_channel *ch;
 720         u8 isr;
 721         u8 cause;
 722         unsigned long lock_flags;
 723
 724         if (!brd)
 725                 return;
 726
 727         if (port >= brd->maxports)
 728                 return;
 729
 730         ch = brd->channels[port];
 731         if (!ch)
 732                 return;
 733
 734         /* Here we try to figure out what caused the interrupt to happen */
 735         while (1) {
 736
 737                 isr = readb(&ch->ch_neo_uart->isr_fcr);
 738
 739                 /* Bail if no pending interrupt */
 740                 if (isr & UART_IIR_NO_INT)
 741                         break;
 742
 743                 /*
 744                  * Yank off the upper 2 bits, which just show that the FIFO's are enabled.
 745                  */
 746                 isr &= ~(UART_17158_IIR_FIFO_ENABLED);
 747
 748                 jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d isr: %x\n",
 749                         __FILE__, __LINE__, isr);
 750
 751                 if (isr & (UART_17158_IIR_RDI_TIMEOUT | UART_IIR_RDI)) {
 752                         /* Read data from uart -> queue */
 753                         neo_copy_data_from_uart_to_queue(ch);
 754
 755                         /* Call our tty layer to enforce queue flow control if needed. */
 756                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 757                         jsm_check_queue_flow_control(ch);
 758                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 759                 }
 760
 761                 if (isr & UART_IIR_THRI) {
 762                         /* Transfer data (if any) from Write Queue -> UART. */
 763                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 764                         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 765                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 766                         neo_copy_data_from_queue_to_uart(ch);
 767                 }
 768
 769                 if (isr & UART_17158_IIR_XONXOFF) {
 770                         cause = readb(&ch->ch_neo_uart->xoffchar1);
 771
 772                         jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 773                                 "Port %d. Got ISR_XONXOFF: cause:%x\n",
 774                                 port, cause);
 775
 776                         /*
 777                          * Since the UART detected either an XON or
 778                          * XOFF match, we need to figure out which
 779                          * one it was, so we can suspend or resume data flow.
 780                          */
 781                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 782                         if (cause == UART_17158_XON_DETECT) {
 783                                 /* Is output stopped right now, if so, resume it */
 784                                 if (brd->channels[port]->ch_flags & CH_STOP) {
 785                                         ch->ch_flags &= ~(CH_STOP);
 786                                 }
 787                                 jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 788                                         "Port %d. XON detected in incoming data\n",
 789                                         port);
 790                         }
 791                         else if (cause == UART_17158_XOFF_DETECT) {
 792                                 if (!(brd->channels[port]->ch_flags & CH_STOP)) {
 793                                         ch->ch_flags |= CH_STOP;
 794                                         jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 795                                                 "Setting CH_STOP\n");
 796                                 }
 797                                 jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 798                                         "Port: %d. XOFF detected in incoming data\n",
 799                                         port);
 800                         }
 801                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 802                 }
 803
 804                 if (isr & UART_17158_IIR_HWFLOW_STATE_CHANGE) {
 805                         /*
 806                          * If we get here, this means the hardware is doing auto flow control.
 807                          * Check to see whether RTS/DTR or CTS/DSR caused this interrupt.
 808                          */
 809                         cause = readb(&ch->ch_neo_uart->mcr);
 810
 811                         /* Which pin is doing auto flow? RTS or DTR? */
 812                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 813                         if ((cause & 0x4) == 0) {
 814                                 if (cause & UART_MCR_RTS)
 815                                         ch->ch_mostat |= UART_MCR_RTS;
 816                                 else
 817                                         ch->ch_mostat &= ~(UART_MCR_RTS);
 818                         } else {
 819                                 if (cause & UART_MCR_DTR)
 820                                         ch->ch_mostat |= UART_MCR_DTR;
 821                                 else
 822                                         ch->ch_mostat &= ~(UART_MCR_DTR);
 823                         }
 824                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 825                 }
 826
 827                 /* Parse any modem signal changes */
 828                 jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 829                         "MOD_STAT: sending to parse_modem_sigs\n");
 830                 spin_lock_irqsave(&ch->uart_port.lock, lock_flags);
 831                 neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
 832                 spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags);
 833         }
 834 }
 835
 836 static inline void neo_parse_lsr(struct jsm_board *brd, u32 port)
 837 {
 838         struct jsm_channel *ch;
 839         int linestatus;
 840         unsigned long lock_flags;
 841
 842         if (!brd)
 843                 return;
 844
 845         if (port >= brd->maxports)
 846                 return;
 847
 848         ch = brd->channels[port];
 849         if (!ch)
 850                 return;
 851
 852         linestatus = readb(&ch->ch_neo_uart->lsr);
 853
 854         jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d port: %d linestatus: %x\n",
 855                 __FILE__, __LINE__, port, linestatus);
 856
 857         ch->ch_cached_lsr |= linestatus;
 858
 859         if (ch->ch_cached_lsr & UART_LSR_DR) {
 860                 /* Read data from uart -> queue */
 861                 neo_copy_data_from_uart_to_queue(ch);
 862                 spin_lock_irqsave(&ch->ch_lock, lock_flags);
 863                 jsm_check_queue_flow_control(ch);
 864                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 865         }
 866
 867         /*
 868          * This is a special flag. It indicates that at least 1
 869          * RX error (parity, framing, or break) has happened.
 870          * Mark this in our struct, which will tell me that I have
 871          *to do the special RX+LSR read for this FIFO load.
 872          */
 873         if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
 874                 jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 875                         "%s:%d Port: %d Got an RX error, need to parse LSR\n",
 876                         __FILE__, __LINE__, port);
 877
 878         /*
 879          * The next 3 tests should *NOT* happen, as the above test
 880          * should encapsulate all 3... At least, thats what Exar says.
 881          */
 882
 883         if (linestatus & UART_LSR_PE) {
 884                 ch->ch_err_parity++;
 885                 jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. PAR ERR!\n",
 886                         __FILE__, __LINE__, port);
 887         }
 888
 889         if (linestatus & UART_LSR_FE) {
 890                 ch->ch_err_frame++;
 891                 jsm_dbg(INTR, &ch->ch_bd->pci_dev, "%s:%d Port: %d. FRM ERR!\n",
 892                         __FILE__, __LINE__, port);
 893         }
 894
 895         if (linestatus & UART_LSR_BI) {
 896                 ch->ch_err_break++;
 897                 jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 898                         "%s:%d Port: %d. BRK INTR!\n",
 899                         __FILE__, __LINE__, port);
 900         }
 901
 902         if (linestatus & UART_LSR_OE) {
 903                 /*
 904                  * Rx Oruns. Exar says that an orun will NOT corrupt
 905                  * the FIFO. It will just replace the holding register
 906                  * with this new data byte. So basically just ignore this.
 907                  * Probably we should eventually have an orun stat in our driver...
 908                  */
 909                 ch->ch_err_overrun++;
 910                 jsm_dbg(INTR, &ch->ch_bd->pci_dev,
 911                         "%s:%d Port: %d. Rx Overrun!\n",
 912                         __FILE__, __LINE__, port);
 913         }
 914
 915         if (linestatus & UART_LSR_THRE) {
 916                 spin_lock_irqsave(&ch->ch_lock, lock_flags);
 917                 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 918                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 919
 920                 /* Transfer data (if any) from Write Queue -> UART. */
 921                 neo_copy_data_from_queue_to_uart(ch);
 922         }
 923         else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {
 924                 spin_lock_irqsave(&ch->ch_lock, lock_flags);
 925                 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 926                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 927
 928                 /* Transfer data (if any) from Write Queue -> UART. */
 929                 neo_copy_data_from_queue_to_uart(ch);
 930         }
 931 }
 932
 933 /*
 934  * neo_param()
 935  * Send any/all changes to the line to the UART.
 936  */
 937 static void neo_param(struct jsm_channel *ch)
 938 {
 939         u8 lcr = 0;
 940         u8 uart_lcr, ier;
 941         u32 baud;
 942         int quot;
 943         struct jsm_board *bd;
 944
 945         bd = ch->ch_bd;
 946         if (!bd)
 947                 return;
 948
 949         /*
 950          * If baud rate is zero, flush queues, and set mval to drop DTR.
 951          */
 952         if ((ch->ch_c_cflag & (CBAUD)) == 0) {
 953                 ch->ch_r_head = ch->ch_r_tail = 0;
 954                 ch->ch_e_head = ch->ch_e_tail = 0;
 955
 956                 neo_flush_uart_write(ch);
 957                 neo_flush_uart_read(ch);
 958
 959                 ch->ch_flags |= (CH_BAUD0);
 960                 ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
 961                 neo_assert_modem_signals(ch);
 962                 return;
 963
 964         } else {
 965                 int i;
 966                 unsigned int cflag;
 967                 static struct {
 968                         unsigned int rate;
 969                         unsigned int cflag;
 970                 } baud_rates[] = {
 971                         { 921600, B921600 },
 972                         { 460800, B460800 },
 973                         { 230400, B230400 },
 974                         { 115200, B115200 },
 975                         {  57600, B57600  },
 976                         {  38400, B38400  },
 977                         {  19200, B19200  },
 978                         {   9600, B9600   },
 979                         {   4800, B4800   },
 980                         {   2400, B2400   },
 981                         {   1200, B1200   },
 982                         {    600, B600    },
 983                         {    300, B300    },
 984                         {    200, B200    },
 985                         {    150, B150    },
 986                         {    134, B134    },
 987                         {    110, B110    },
 988                         {     75, B75     },
 989                         {     50, B50     },
 990                 };
 991
 992                 cflag = C_BAUD(ch->uart_port.state->port.tty);
 993                 baud = 9600;
 994                 for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
 995                         if (baud_rates[i].cflag == cflag) {
 996                                 baud = baud_rates[i].rate;
 997                                 break;
 998                         }
 999                 }
1000
1001                 if (ch->ch_flags & CH_BAUD0)
1002                         ch->ch_flags &= ~(CH_BAUD0);
1003         }
1004
1005         if (ch->ch_c_cflag & PARENB)
1006                 lcr |= UART_LCR_PARITY;
1007
1008         if (!(ch->ch_c_cflag & PARODD))
1009                 lcr |= UART_LCR_EPAR;
1010
1011         /*
1012          * Not all platforms support mark/space parity,
1013          * so this will hide behind an ifdef.
1014          */
1015 #ifdef CMSPAR
1016         if (ch->ch_c_cflag & CMSPAR)
1017                 lcr |= UART_LCR_SPAR;
1018 #endif
1019
1020         if (ch->ch_c_cflag & CSTOPB)
1021                 lcr |= UART_LCR_STOP;
1022
1023         switch (ch->ch_c_cflag & CSIZE) {
1024         case CS5:
1025                 lcr |= UART_LCR_WLEN5;
1026                 break;
1027         case CS6:
1028                 lcr |= UART_LCR_WLEN6;
1029                 break;
1030         case CS7:
1031                 lcr |= UART_LCR_WLEN7;
1032                 break;
1033         case CS8:
1034         default:
1035                 lcr |= UART_LCR_WLEN8;
1036         break;
1037         }
1038
1039         ier = readb(&ch->ch_neo_uart->ier);
1040         uart_lcr = readb(&ch->ch_neo_uart->lcr);
1041
1042         quot = ch->ch_bd->bd_dividend / baud;
1043
1044         if (quot != 0) {
1045                 writeb(UART_LCR_DLAB, &ch->ch_neo_uart->lcr);
1046                 writeb((quot & 0xff), &ch->ch_neo_uart->txrx);
1047                 writeb((quot >> 8), &ch->ch_neo_uart->ier);
1048                 writeb(lcr, &ch->ch_neo_uart->lcr);
1049         }
1050
1051         if (uart_lcr != lcr)
1052                 writeb(lcr, &ch->ch_neo_uart->lcr);
1053
1054         if (ch->ch_c_cflag & CREAD)
1055                 ier |= (UART_IER_RDI | UART_IER_RLSI);
1056
1057         ier |= (UART_IER_THRI | UART_IER_MSI);
1058
1059         writeb(ier, &ch->ch_neo_uart->ier);
1060
1061         /* Set new start/stop chars */
1062         neo_set_new_start_stop_chars(ch);
1063
1064         if (ch->ch_c_cflag & CRTSCTS)
1065                 neo_set_cts_flow_control(ch);
1066         else if (ch->ch_c_iflag & IXON) {
1067                 /* If start/stop is set to disable, then we should disable flow control */
1068                 if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1069                         neo_set_no_output_flow_control(ch);
1070                 else
1071                         neo_set_ixon_flow_control(ch);
1072         }
1073         else
1074                 neo_set_no_output_flow_control(ch);
1075
1076         if (ch->ch_c_cflag & CRTSCTS)
1077                 neo_set_rts_flow_control(ch);
1078         else if (ch->ch_c_iflag & IXOFF) {
1079                 /* If start/stop is set to disable, then we should disable flow control */
1080                 if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1081                         neo_set_no_input_flow_control(ch);
1082                 else
1083                         neo_set_ixoff_flow_control(ch);
1084         }
1085         else
1086                 neo_set_no_input_flow_control(ch);
1087         /*
1088          * Adjust the RX FIFO Trigger level if baud is less than 9600.
1089          * Not exactly elegant, but this is needed because of the Exar chip's
1090          * delay on firing off the RX FIFO interrupt on slower baud rates.
1091          */
1092         if (baud < 9600) {
1093                 writeb(1, &ch->ch_neo_uart->rfifo);
1094                 ch->ch_r_tlevel = 1;
1095         }
1096
1097         neo_assert_modem_signals(ch);
1098
1099         /* Get current status of the modem signals now */
1100         neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
1101         return;
1102 }
1103
1104 /*
1105  * jsm_neo_intr()
1106  *
1107  * Neo specific interrupt handler.
1108  */
1109 static irqreturn_t neo_intr(int irq, void *voidbrd)
1110 {
1111         struct jsm_board *brd = voidbrd;
1112         struct jsm_channel *ch;
1113         int port = 0;
1114         int type = 0;
1115         int current_port;
1116         u32 tmp;
1117         u32 uart_poll;
1118         unsigned long lock_flags;
1119         unsigned long lock_flags2;
1120         int outofloop_count = 0;
1121
1122         /* Lock out the slow poller from running on this board. */
1123         spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
1124
1125         /*
1126          * Read in "extended" IRQ information from the 32bit Neo register.
1127          * Bits 0-7: What port triggered the interrupt.
1128          * Bits 8-31: Each 3bits indicate what type of interrupt occurred.
1129          */
1130         uart_poll = readl(brd->re_map_membase + UART_17158_POLL_ADDR_OFFSET);
1131
1132         jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
1133                 __FILE__, __LINE__, uart_poll);
1134
1135         if (!uart_poll) {
1136                 jsm_dbg(INTR, &brd->pci_dev,
1137                         "Kernel interrupted to me, but no pending interrupts...\n");
1138                 spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1139                 return IRQ_NONE;
1140         }
1141
1142         /* At this point, we have at least SOMETHING to service, dig further... */
1143
1144         current_port = 0;
1145
1146         /* Loop on each port */
1147         while (((uart_poll & 0xff) != 0) && (outofloop_count < 0xff)){
1148
1149                 tmp = uart_poll;
1150                 outofloop_count++;
1151
1152                 /* Check current port to see if it has interrupt pending */
1153                 if ((tmp & jsm_offset_table[current_port]) != 0) {
1154                         port = current_port;
1155                         type = tmp >> (8 + (port * 3));
1156                         type &= 0x7;
1157                 } else {
1158                         current_port++;
1159                         continue;
1160                 }
1161
1162                 jsm_dbg(INTR, &brd->pci_dev, "%s:%d port: %x type: %x\n",
1163                         __FILE__, __LINE__, port, type);
1164
1165                 /* Remove this port + type from uart_poll */
1166                 uart_poll &= ~(jsm_offset_table[port]);
1167
1168                 if (!type) {
1169                         /* If no type, just ignore it, and move onto next port */
1170                         jsm_dbg(INTR, &brd->pci_dev,
1171                                 "Interrupt with no type! port: %d\n", port);
1172                         continue;
1173                 }
1174
1175                 /* Switch on type of interrupt we have */
1176                 switch (type) {
1177
1178                 case UART_17158_RXRDY_TIMEOUT:
1179                         /*
1180                          * RXRDY Time-out is cleared by reading data in the
1181                         * RX FIFO until it falls below the trigger level.
1182                          */
1183
1184                         /* Verify the port is in range. */
1185                         if (port >= brd->nasync)
1186                                 continue;
1187
1188                         ch = brd->channels[port];
1189                         neo_copy_data_from_uart_to_queue(ch);
1190
1191                         /* Call our tty layer to enforce queue flow control if needed. */
1192                         spin_lock_irqsave(&ch->ch_lock, lock_flags2);
1193                         jsm_check_queue_flow_control(ch);
1194                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags2);
1195
1196                         continue;
1197
1198                 case UART_17158_RX_LINE_STATUS:
1199                         /*
1200                          * RXRDY and RX LINE Status (logic OR of LSR[4:1])
1201                          */
1202                         neo_parse_lsr(brd, port);
1203                         continue;
1204
1205                 case UART_17158_TXRDY:
1206                         /*
1207                          * TXRDY interrupt clears after reading ISR register for the UART channel.
1208                          */
1209
1210                         /*
1211                          * Yes, this is odd...
1212                          * Why would I check EVERY possibility of type of
1213                          * interrupt, when we know its TXRDY???
1214                          * Becuz for some reason, even tho we got triggered for TXRDY,
1215                          * it seems to be occasionally wrong. Instead of TX, which
1216                          * it should be, I was getting things like RXDY too. Weird.
1217                          */
1218                         neo_parse_isr(brd, port);
1219                         continue;
1220
1221                 case UART_17158_MSR:
1222                         /*
1223                          * MSR or flow control was seen.
1224                          */
1225                         neo_parse_isr(brd, port);
1226                         continue;
1227
1228                 default:
1229                         /*
1230                          * The UART triggered us with a bogus interrupt type.
1231                          * It appears the Exar chip, when REALLY bogged down, will throw
1232                          * these once and awhile.
1233                          * Its harmless, just ignore it and move on.
1234                          */
1235                         jsm_dbg(INTR, &brd->pci_dev,
1236                                 "%s:%d Unknown Interrupt type: %x\n",
1237                                 __FILE__, __LINE__, type);
1238                         continue;
1239                 }
1240         }
1241
1242         spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1243
1244         jsm_dbg(INTR, &brd->pci_dev, "finish\n");
1245         return IRQ_HANDLED;
1246 }
1247
1248 /*
1249  * Neo specific way of turning off the receiver.
1250  * Used as a way to enforce queue flow control when in
1251  * hardware flow control mode.
1252  */
1253 static void neo_disable_receiver(struct jsm_channel *ch)
1254 {
1255         u8 tmp = readb(&ch->ch_neo_uart->ier);
1256         tmp &= ~(UART_IER_RDI);
1257         writeb(tmp, &ch->ch_neo_uart->ier);
1258
1259         /* flush write operation */
1260         neo_pci_posting_flush(ch->ch_bd);
1261 }
1262
1263
1264 /*
1265  * Neo specific way of turning on the receiver.
1266  * Used as a way to un-enforce queue flow control when in
1267  * hardware flow control mode.
1268  */
1269 static void neo_enable_receiver(struct jsm_channel *ch)
1270 {
1271         u8 tmp = readb(&ch->ch_neo_uart->ier);
1272         tmp |= (UART_IER_RDI);
1273         writeb(tmp, &ch->ch_neo_uart->ier);
1274
1275         /* flush write operation */
1276         neo_pci_posting_flush(ch->ch_bd);
1277 }
1278
1279 static void neo_send_start_character(struct jsm_channel *ch)
1280 {
1281         if (!ch)
1282                 return;
1283
1284         if (ch->ch_startc != __DISABLED_CHAR) {
1285                 ch->ch_xon_sends++;
1286                 writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
1287
1288                 /* flush write operation */
1289                 neo_pci_posting_flush(ch->ch_bd);
1290         }
1291 }
1292
1293 static void neo_send_stop_character(struct jsm_channel *ch)
1294 {
1295         if (!ch)
1296                 return;
1297
1298         if (ch->ch_stopc != __DISABLED_CHAR) {
1299                 ch->ch_xoff_sends++;
1300                 writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
1301
1302                 /* flush write operation */
1303                 neo_pci_posting_flush(ch->ch_bd);
1304         }
1305 }
1306
1307 /*
1308  * neo_uart_init
1309  */
1310 static void neo_uart_init(struct jsm_channel *ch)
1311 {
1312         writeb(0, &ch->ch_neo_uart->ier);
1313         writeb(0, &ch->ch_neo_uart->efr);
1314         writeb(UART_EFR_ECB, &ch->ch_neo_uart->efr);
1315
1316         /* Clear out UART and FIFO */
1317         readb(&ch->ch_neo_uart->txrx);
1318         writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
1319         readb(&ch->ch_neo_uart->lsr);
1320         readb(&ch->ch_neo_uart->msr);
1321
1322         ch->ch_flags |= CH_FIFO_ENABLED;
1323
1324         /* Assert any signals we want up */
1325         writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
1326 }
1327
1328 /*
1329  * Make the UART completely turn off.
1330  */
1331 static void neo_uart_off(struct jsm_channel *ch)
1332 {
1333         /* Turn off UART enhanced bits */
1334         writeb(0, &ch->ch_neo_uart->efr);
1335
1336         /* Stop all interrupts from occurring. */
1337         writeb(0, &ch->ch_neo_uart->ier);
1338 }
1339
1340 static u32 neo_get_uart_bytes_left(struct jsm_channel *ch)
1341 {
1342         u8 left = 0;
1343         u8 lsr = readb(&ch->ch_neo_uart->lsr);
1344
1345         /* We must cache the LSR as some of the bits get reset once read... */
1346         ch->ch_cached_lsr |= lsr;
1347
1348         /* Determine whether the Transmitter is empty or not */
1349         if (!(lsr & UART_LSR_TEMT))
1350                 left = 1;
1351         else {
1352                 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1353                 left = 0;
1354         }
1355
1356         return left;
1357 }
1358
1359 /* Channel lock MUST be held by the calling function! */
1360 static void neo_send_break(struct jsm_channel *ch)
1361 {
1362         /*
1363          * Set the time we should stop sending the break.
1364          * If we are already sending a break, toss away the existing
1365          * time to stop, and use this new value instead.
1366          */
1367
1368         /* Tell the UART to start sending the break */
1369         if (!(ch->ch_flags & CH_BREAK_SENDING)) {
1370                 u8 temp = readb(&ch->ch_neo_uart->lcr);
1371                 writeb((temp | UART_LCR_SBC), &ch->ch_neo_uart->lcr);
1372                 ch->ch_flags |= (CH_BREAK_SENDING);
1373
1374                 /* flush write operation */
1375                 neo_pci_posting_flush(ch->ch_bd);
1376         }
1377 }
1378
1379 /*
1380  * neo_send_immediate_char.
1381  *
1382  * Sends a specific character as soon as possible to the UART,
1383  * jumping over any bytes that might be in the write queue.
1384  *
1385  * The channel lock MUST be held by the calling function.
1386  */
1387 static void neo_send_immediate_char(struct jsm_channel *ch, unsigned char c)
1388 {
1389         if (!ch)
1390                 return;
1391
1392         writeb(c, &ch->ch_neo_uart->txrx);
1393
1394         /* flush write operation */
1395         neo_pci_posting_flush(ch->ch_bd);
1396 }
1397
1398 struct board_ops jsm_neo_ops = {
1399         .intr                           = neo_intr,
1400         .uart_init                      = neo_uart_init,
1401         .uart_off                       = neo_uart_off,
1402         .param                          = neo_param,
1403         .assert_modem_signals           = neo_assert_modem_signals,
1404         .flush_uart_write               = neo_flush_uart_write,
1405         .flush_uart_read                = neo_flush_uart_read,
1406         .disable_receiver               = neo_disable_receiver,
1407         .enable_receiver                = neo_enable_receiver,
1408         .send_break                     = neo_send_break,
1409         .clear_break                    = neo_clear_break,
1410         .send_start_character           = neo_send_start_character,
1411         .send_stop_character            = neo_send_stop_character,
1412         .copy_data_from_queue_to_uart   = neo_copy_data_from_queue_to_uart,
1413         .get_uart_bytes_left            = neo_get_uart_bytes_left,
1414         .send_immediate_char            = neo_send_immediate_char
1415 };