drivers/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  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 * Temple Place - Suite 330, Boston,
  19  * MA  02111-1307, USA.
  20  *
  21  * Contact Information:
  22  * Scott H Kilau <Scott_Kilau@digi.com>
  23  * Wendy Xiong   <wendyx@us.ibm.com>
  24  *
  25  ***********************************************************************/
  26 #include <linux/delay.h>        /* For udelay */
  27 #include <linux/serial_reg.h>   /* For the various UART offsets */
  28 #include <linux/tty.h>
  29 #include <linux/pci.h>
  30 #include <asm/io.h>
  31
  32 #include "jsm.h"                /* Driver main header file */
  33
  34 static u32 jsm_offset_table[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
  35
  36 /*
  37  * This function allows calls to ensure that all outstanding
  38  * PCI writes have been completed, by doing a PCI read against
  39  * a non-destructive, read-only location on the Neo card.
  40  *
  41  * In this case, we are reading the DVID (Read-only Device Identification)
  42  * value of the Neo card.
  43  */
  44 static inline void neo_pci_posting_flush(struct jsm_board *bd)
  45 {
  46       readb(bd->re_map_membase + 0x8D);
  47 }
  48
  49 static void neo_set_cts_flow_control(struct jsm_channel *ch)
  50 {
  51         u8 ier, efr;
  52         ier = readb(&ch->ch_neo_uart->ier);
  53         efr = readb(&ch->ch_neo_uart->efr);
  54
  55         jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting CTSFLOW\n");
  56
  57         /* Turn on auto CTS flow control */
  58         ier |= (UART_17158_IER_CTSDSR);
  59         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_CTSDSR);
  60
  61         /* Turn off auto Xon flow control */
  62         efr &= ~(UART_17158_EFR_IXON);
  63
  64         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
  65         writeb(0, &ch->ch_neo_uart->efr);
  66
  67         /* Turn on UART enhanced bits */
  68         writeb(efr, &ch->ch_neo_uart->efr);
  69
  70         /* Turn on table D, with 8 char hi/low watermarks */
  71         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
  72
  73         /* Feed the UART our trigger levels */
  74         writeb(8, &ch->ch_neo_uart->tfifo);
  75         ch->ch_t_tlevel = 8;
  76
  77         writeb(ier, &ch->ch_neo_uart->ier);
  78 }
  79
  80 static void neo_set_rts_flow_control(struct jsm_channel *ch)
  81 {
  82         u8 ier, efr;
  83         ier = readb(&ch->ch_neo_uart->ier);
  84         efr = readb(&ch->ch_neo_uart->efr);
  85
  86         jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting RTSFLOW\n");
  87
  88         /* Turn on auto RTS flow control */
  89         ier |= (UART_17158_IER_RTSDTR);
  90         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_RTSDTR);
  91
  92         /* Turn off auto Xoff flow control */
  93         ier &= ~(UART_17158_IER_XOFF);
  94         efr &= ~(UART_17158_EFR_IXOFF);
  95
  96         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
  97         writeb(0, &ch->ch_neo_uart->efr);
  98
  99         /* Turn on UART enhanced bits */
 100         writeb(efr, &ch->ch_neo_uart->efr);
 101
 102         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_4DELAY), &ch->ch_neo_uart->fctr);
 103         ch->ch_r_watermark = 4;
 104
 105         writeb(56, &ch->ch_neo_uart->rfifo);
 106         ch->ch_r_tlevel = 56;
 107
 108         writeb(ier, &ch->ch_neo_uart->ier);
 109
 110         /*
 111          * From the Neo UART spec sheet:
 112          * The auto RTS/DTR function must be started by asserting
 113          * RTS/DTR# output pin (MCR bit-0 or 1 to logic 1 after
 114          * it is enabled.
 115          */
 116         ch->ch_mostat |= (UART_MCR_RTS);
 117 }
 118
 119
 120 static void neo_set_ixon_flow_control(struct jsm_channel *ch)
 121 {
 122         u8 ier, efr;
 123         ier = readb(&ch->ch_neo_uart->ier);
 124         efr = readb(&ch->ch_neo_uart->efr);
 125
 126         jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting IXON FLOW\n");
 127
 128         /* Turn off auto CTS flow control */
 129         ier &= ~(UART_17158_IER_CTSDSR);
 130         efr &= ~(UART_17158_EFR_CTSDSR);
 131
 132         /* Turn on auto Xon flow control */
 133         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXON);
 134
 135         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 136         writeb(0, &ch->ch_neo_uart->efr);
 137
 138         /* Turn on UART enhanced bits */
 139         writeb(efr, &ch->ch_neo_uart->efr);
 140
 141         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 142         ch->ch_r_watermark = 4;
 143
 144         writeb(32, &ch->ch_neo_uart->rfifo);
 145         ch->ch_r_tlevel = 32;
 146
 147         /* Tell UART what start/stop chars it should be looking for */
 148         writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
 149         writeb(0, &ch->ch_neo_uart->xonchar2);
 150
 151         writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
 152         writeb(0, &ch->ch_neo_uart->xoffchar2);
 153
 154         writeb(ier, &ch->ch_neo_uart->ier);
 155 }
 156
 157 static void neo_set_ixoff_flow_control(struct jsm_channel *ch)
 158 {
 159         u8 ier, efr;
 160         ier = readb(&ch->ch_neo_uart->ier);
 161         efr = readb(&ch->ch_neo_uart->efr);
 162
 163         jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Setting IXOFF FLOW\n");
 164
 165         /* Turn off auto RTS flow control */
 166         ier &= ~(UART_17158_IER_RTSDTR);
 167         efr &= ~(UART_17158_EFR_RTSDTR);
 168
 169         /* Turn on auto Xoff flow control */
 170         ier |= (UART_17158_IER_XOFF);
 171         efr |= (UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
 172
 173         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 174         writeb(0, &ch->ch_neo_uart->efr);
 175
 176         /* Turn on UART enhanced bits */
 177         writeb(efr, &ch->ch_neo_uart->efr);
 178
 179         /* Turn on table D, with 8 char hi/low watermarks */
 180         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 181
 182         writeb(8, &ch->ch_neo_uart->tfifo);
 183         ch->ch_t_tlevel = 8;
 184
 185         /* Tell UART what start/stop chars it should be looking for */
 186         writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
 187         writeb(0, &ch->ch_neo_uart->xonchar2);
 188
 189         writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
 190         writeb(0, &ch->ch_neo_uart->xoffchar2);
 191
 192         writeb(ier, &ch->ch_neo_uart->ier);
 193 }
 194
 195 static void neo_set_no_input_flow_control(struct jsm_channel *ch)
 196 {
 197         u8 ier, efr;
 198         ier = readb(&ch->ch_neo_uart->ier);
 199         efr = readb(&ch->ch_neo_uart->efr);
 200
 201         jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Unsetting Input FLOW\n");
 202
 203         /* Turn off auto RTS flow control */
 204         ier &= ~(UART_17158_IER_RTSDTR);
 205         efr &= ~(UART_17158_EFR_RTSDTR);
 206
 207         /* Turn off auto Xoff flow control */
 208         ier &= ~(UART_17158_IER_XOFF);
 209         if (ch->ch_c_iflag & IXON)
 210                 efr &= ~(UART_17158_EFR_IXOFF);
 211         else
 212                 efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXOFF);
 213
 214         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 215         writeb(0, &ch->ch_neo_uart->efr);
 216
 217         /* Turn on UART enhanced bits */
 218         writeb(efr, &ch->ch_neo_uart->efr);
 219
 220         /* Turn on table D, with 8 char hi/low watermarks */
 221         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 222
 223         ch->ch_r_watermark = 0;
 224
 225         writeb(16, &ch->ch_neo_uart->tfifo);
 226         ch->ch_t_tlevel = 16;
 227
 228         writeb(16, &ch->ch_neo_uart->rfifo);
 229         ch->ch_r_tlevel = 16;
 230
 231         writeb(ier, &ch->ch_neo_uart->ier);
 232 }
 233
 234 static void neo_set_no_output_flow_control(struct jsm_channel *ch)
 235 {
 236         u8 ier, efr;
 237         ier = readb(&ch->ch_neo_uart->ier);
 238         efr = readb(&ch->ch_neo_uart->efr);
 239
 240         jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "Unsetting Output FLOW\n");
 241
 242         /* Turn off auto CTS flow control */
 243         ier &= ~(UART_17158_IER_CTSDSR);
 244         efr &= ~(UART_17158_EFR_CTSDSR);
 245
 246         /* Turn off auto Xon flow control */
 247         if (ch->ch_c_iflag & IXOFF)
 248                 efr &= ~(UART_17158_EFR_IXON);
 249         else
 250                 efr &= ~(UART_17158_EFR_ECB | UART_17158_EFR_IXON);
 251
 252         /* Why? Becuz Exar's spec says we have to zero it out before setting it */
 253         writeb(0, &ch->ch_neo_uart->efr);
 254
 255         /* Turn on UART enhanced bits */
 256         writeb(efr, &ch->ch_neo_uart->efr);
 257
 258         /* Turn on table D, with 8 char hi/low watermarks */
 259         writeb((UART_17158_FCTR_TRGD | UART_17158_FCTR_RTS_8DELAY), &ch->ch_neo_uart->fctr);
 260
 261         ch->ch_r_watermark = 0;
 262
 263         writeb(16, &ch->ch_neo_uart->tfifo);
 264         ch->ch_t_tlevel = 16;
 265
 266         writeb(16, &ch->ch_neo_uart->rfifo);
 267         ch->ch_r_tlevel = 16;
 268
 269         writeb(ier, &ch->ch_neo_uart->ier);
 270 }
 271
 272 static inline void neo_set_new_start_stop_chars(struct jsm_channel *ch)
 273 {
 274
 275         /* if hardware flow control is set, then skip this whole thing */
 276         if (ch->ch_c_cflag & CRTSCTS)
 277                 return;
 278
 279         jsm_printk(PARAM, INFO, &ch->ch_bd->pci_dev, "start\n");
 280
 281         /* Tell UART what start/stop chars it should be looking for */
 282         writeb(ch->ch_startc, &ch->ch_neo_uart->xonchar1);
 283         writeb(0, &ch->ch_neo_uart->xonchar2);
 284
 285         writeb(ch->ch_stopc, &ch->ch_neo_uart->xoffchar1);
 286         writeb(0, &ch->ch_neo_uart->xoffchar2);
 287 }
 288
 289 static void neo_copy_data_from_uart_to_queue(struct jsm_channel *ch)
 290 {
 291         int qleft = 0;
 292         u8 linestatus = 0;
 293         u8 error_mask = 0;
 294         int n = 0;
 295         int total = 0;
 296         u16 head;
 297         u16 tail;
 298
 299         if (!ch)
 300                 return;
 301
 302         /* cache head and tail of queue */
 303         head = ch->ch_r_head & RQUEUEMASK;
 304         tail = ch->ch_r_tail & RQUEUEMASK;
 305
 306         /* Get our cached LSR */
 307         linestatus = ch->ch_cached_lsr;
 308         ch->ch_cached_lsr = 0;
 309
 310         /* Store how much space we have left in the queue */
 311         if ((qleft = tail - head - 1) < 0)
 312                 qleft += RQUEUEMASK + 1;
 313
 314         /*
 315          * If the UART is not in FIFO mode, force the FIFO copy to
 316          * NOT be run, by setting total to 0.
 317          *
 318          * On the other hand, if the UART IS in FIFO mode, then ask
 319          * the UART to give us an approximation of data it has RX'ed.
 320          */
 321         if (!(ch->ch_flags & CH_FIFO_ENABLED))
 322                 total = 0;
 323         else {
 324                 total = readb(&ch->ch_neo_uart->rfifo);
 325
 326                 /*
 327                  * EXAR chip bug - RX FIFO COUNT - Fudge factor.
 328                  *
 329                  * This resolves a problem/bug with the Exar chip that sometimes
 330                  * returns a bogus value in the rfifo register.
 331                  * The count can be any where from 0-3 bytes "off".
 332                  * Bizarre, but true.
 333                  */
 334                 total -= 3;
 335         }
 336
 337         /*
 338          * Finally, bound the copy to make sure we don't overflow
 339          * our own queue...
 340          * The byte by byte copy loop below this loop this will
 341          * deal with the queue overflow possibility.
 342          */
 343         total = min(total, qleft);
 344
 345         while (total > 0) {
 346                 /*
 347                  * Grab the linestatus register, we need to check
 348                  * to see if there are any errors in the FIFO.
 349                  */
 350                 linestatus = readb(&ch->ch_neo_uart->lsr);
 351
 352                 /*
 353                  * Break out if there is a FIFO error somewhere.
 354                  * This will allow us to go byte by byte down below,
 355                  * finding the exact location of the error.
 356                  */
 357                 if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
 358                         break;
 359
 360                 /* Make sure we don't go over the end of our queue */
 361                 n = min(((u32) total), (RQUEUESIZE - (u32) head));
 362
 363                 /*
 364                  * Cut down n even further if needed, this is to fix
 365                  * a problem with memcpy_fromio() with the Neo on the
 366                  * IBM pSeries platform.
 367                  * 15 bytes max appears to be the magic number.
 368                  */
 369                 n = min((u32) n, (u32) 12);
 370
 371                 /*
 372                  * Since we are grabbing the linestatus register, which
 373                  * will reset some bits after our read, we need to ensure
 374                  * we don't miss our TX FIFO emptys.
 375                  */
 376                 if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR))
 377                         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 378
 379                 linestatus = 0;
 380
 381                 /* Copy data from uart to the queue */
 382                 memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, n);
 383                 /*
 384                  * Since RX_FIFO_DATA_ERROR was 0, we are guarenteed
 385                  * that all the data currently in the FIFO is free of
 386                  * breaks and parity/frame/orun errors.
 387                  */
 388                 memset(ch->ch_equeue + head, 0, n);
 389
 390                 /* Add to and flip head if needed */
 391                 head = (head + n) & RQUEUEMASK;
 392                 total -= n;
 393                 qleft -= n;
 394                 ch->ch_rxcount += n;
 395         }
 396
 397         /*
 398          * Create a mask to determine whether we should
 399          * insert the character (if any) into our queue.
 400          */
 401         if (ch->ch_c_iflag & IGNBRK)
 402                 error_mask |= UART_LSR_BI;
 403
 404         /*
 405          * Now cleanup any leftover bytes still in the UART.
 406          * Also deal with any possible queue overflow here as well.
 407          */
 408         while (1) {
 409
 410                 /*
 411                  * Its possible we have a linestatus from the loop above
 412                  * this, so we "OR" on any extra bits.
 413                  */
 414                 linestatus |= readb(&ch->ch_neo_uart->lsr);
 415
 416                 /*
 417                  * If the chip tells us there is no more data pending to
 418                  * be read, we can then leave.
 419                  * But before we do, cache the linestatus, just in case.
 420                  */
 421                 if (!(linestatus & UART_LSR_DR)) {
 422                         ch->ch_cached_lsr = linestatus;
 423                         break;
 424                 }
 425
 426                 /* No need to store this bit */
 427                 linestatus &= ~UART_LSR_DR;
 428
 429                 /*
 430                  * Since we are grabbing the linestatus register, which
 431                  * will reset some bits after our read, we need to ensure
 432                  * we don't miss our TX FIFO emptys.
 433                  */
 434                 if (linestatus & (UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR)) {
 435                         linestatus &= ~(UART_LSR_THRE | UART_17158_TX_AND_FIFO_CLR);
 436                         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 437                 }
 438
 439                 /*
 440                  * Discard character if we are ignoring the error mask.
 441                  */
 442                 if (linestatus & error_mask) {
 443                         u8 discard;
 444                         linestatus = 0;
 445                         memcpy_fromio(&discard, &ch->ch_neo_uart->txrxburst, 1);
 446                         continue;
 447                 }
 448
 449                 /*
 450                  * If our queue is full, we have no choice but to drop some data.
 451                  * The assumption is that HWFLOW or SWFLOW should have stopped
 452                  * things way way before we got to this point.
 453                  *
 454                  * I decided that I wanted to ditch the oldest data first,
 455                  * I hope thats okay with everyone? Yes? Good.
 456                  */
 457                 while (qleft < 1) {
 458                         jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 459                                 "Queue full, dropping DATA:%x LSR:%x\n",
 460                                 ch->ch_rqueue[tail], ch->ch_equeue[tail]);
 461
 462                         ch->ch_r_tail = tail = (tail + 1) & RQUEUEMASK;
 463                         ch->ch_err_overrun++;
 464                         qleft++;
 465                 }
 466
 467                 memcpy_fromio(ch->ch_rqueue + head, &ch->ch_neo_uart->txrxburst, 1);
 468                 ch->ch_equeue[head] = (u8) linestatus;
 469
 470                 jsm_printk(READ, INFO, &ch->ch_bd->pci_dev,
 471                                 "DATA/LSR pair: %x %x\n", ch->ch_rqueue[head], ch->ch_equeue[head]);
 472
 473                 /* Ditch any remaining linestatus value. */
 474                 linestatus = 0;
 475
 476                 /* Add to and flip head if needed */
 477                 head = (head + 1) & RQUEUEMASK;
 478
 479                 qleft--;
 480                 ch->ch_rxcount++;
 481         }
 482
 483         /*
 484          * Write new final heads to channel structure.
 485          */
 486         ch->ch_r_head = head & RQUEUEMASK;
 487         ch->ch_e_head = head & EQUEUEMASK;
 488         jsm_input(ch);
 489 }
 490
 491 static void neo_copy_data_from_queue_to_uart(struct jsm_channel *ch)
 492 {
 493         u16 head;
 494         u16 tail;
 495         int n;
 496         int s;
 497         int qlen;
 498         u32 len_written = 0;
 499
 500         if (!ch)
 501                 return;
 502
 503         /* No data to write to the UART */
 504         if (ch->ch_w_tail == ch->ch_w_head)
 505                 return;
 506
 507         /* If port is "stopped", don't send any data to the UART */
 508         if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
 509                 return;
 510         /*
 511          * If FIFOs are disabled. Send data directly to txrx register
 512          */
 513         if (!(ch->ch_flags & CH_FIFO_ENABLED)) {
 514                 u8 lsrbits = readb(&ch->ch_neo_uart->lsr);
 515
 516                 ch->ch_cached_lsr |= lsrbits;
 517                 if (ch->ch_cached_lsr & UART_LSR_THRE) {
 518                         ch->ch_cached_lsr &= ~(UART_LSR_THRE);
 519
 520                         writeb(ch->ch_wqueue[ch->ch_w_tail], &ch->ch_neo_uart->txrx);
 521                         jsm_printk(WRITE, INFO, &ch->ch_bd->pci_dev,
 522                                         "Tx data: %x\n", ch->ch_wqueue[ch->ch_w_head]);
 523                         ch->ch_w_tail++;
 524                         ch->ch_w_tail &= WQUEUEMASK;
 525                         ch->ch_txcount++;
 526                 }
 527                 return;
 528         }
 529
 530         /*
 531          * We have to do it this way, because of the EXAR TXFIFO count bug.
 532          */
 533         if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
 534                 return;
 535
 536         len_written = 0;
 537         n = UART_17158_TX_FIFOSIZE - ch->ch_t_tlevel;
 538
 539         /* cache head and tail of queue */
 540         head = ch->ch_w_head & WQUEUEMASK;
 541         tail = ch->ch_w_tail & WQUEUEMASK;
 542         qlen = (head - tail) & WQUEUEMASK;
 543
 544         /* Find minimum of the FIFO space, versus queue length */
 545         n = min(n, qlen);
 546
 547         while (n > 0) {
 548
 549                 s = ((head >= tail) ? head : WQUEUESIZE) - tail;
 550                 s = min(s, n);
 551
 552                 if (s <= 0)
 553                         break;
 554
 555                 memcpy_toio(&ch->ch_neo_uart->txrxburst, ch->ch_wqueue + tail, s);
 556                 /* Add and flip queue if needed */
 557                 tail = (tail + s) & WQUEUEMASK;
 558                 n -= s;
 559                 ch->ch_txcount += s;
 560                 len_written += s;
 561         }
 562
 563         /* Update the final tail */
 564         ch->ch_w_tail = tail & WQUEUEMASK;
 565
 566         if (len_written >= ch->ch_t_tlevel)
 567                 ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 568
 569         if (!jsm_tty_write(&ch->uart_port))
 570                 uart_write_wakeup(&ch->uart_port);
 571 }
 572
 573 static void neo_parse_modem(struct jsm_channel *ch, u8 signals)
 574 {
 575         u8 msignals = signals;
 576
 577         jsm_printk(MSIGS, INFO, &ch->ch_bd->pci_dev,
 578                         "neo_parse_modem: port: %d msignals: %x\n", ch->ch_portnum, msignals);
 579
 580         if (!ch)
 581                 return;
 582
 583         /* Scrub off lower bits. They signify delta's, which I don't care about */
 584         msignals &= 0xf0;
 585
 586         if (msignals & UART_MSR_DCD)
 587                 ch->ch_mistat |= UART_MSR_DCD;
 588         else
 589                 ch->ch_mistat &= ~UART_MSR_DCD;
 590
 591         if (msignals & UART_MSR_DSR)
 592                 ch->ch_mistat |= UART_MSR_DSR;
 593         else
 594                 ch->ch_mistat &= ~UART_MSR_DSR;
 595
 596         if (msignals & UART_MSR_RI)
 597                 ch->ch_mistat |= UART_MSR_RI;
 598         else
 599                 ch->ch_mistat &= ~UART_MSR_RI;
 600
 601         if (msignals & UART_MSR_CTS)
 602                 ch->ch_mistat |= UART_MSR_CTS;
 603         else
 604                 ch->ch_mistat &= ~UART_MSR_CTS;
 605
 606         jsm_printk(MSIGS, INFO, &ch->ch_bd->pci_dev,
 607                         "Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
 608                 ch->ch_portnum,
 609                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
 610                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
 611                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
 612                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
 613                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
 614                 !!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
 615 }
 616
 617 /* Make the UART raise any of the output signals we want up */
 618 static void neo_assert_modem_signals(struct jsm_channel *ch)
 619 {
 620         u8 out;
 621
 622         if (!ch)
 623                 return;
 624
 625         out = ch->ch_mostat;
 626
 627         writeb(out, &ch->ch_neo_uart->mcr);
 628
 629         /* flush write operation */
 630         neo_pci_posting_flush(ch->ch_bd);
 631 }
 632
 633 /*
 634  * Flush the WRITE FIFO on the Neo.
 635  *
 636  * NOTE: Channel lock MUST be held before calling this function!
 637  */
 638 static void neo_flush_uart_write(struct jsm_channel *ch)
 639 {
 640         u8 tmp = 0;
 641         int i = 0;
 642
 643         if (!ch)
 644                 return;
 645
 646         writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
 647
 648         for (i = 0; i < 10; i++) {
 649
 650                 /* Check to see if the UART feels it completely flushed the FIFO. */
 651                 tmp = readb(&ch->ch_neo_uart->isr_fcr);
 652                 if (tmp & 4) {
 653                         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev,
 654                                         "Still flushing TX UART... i: %d\n", i);
 655                         udelay(10);
 656                 }
 657                 else
 658                         break;
 659         }
 660
 661         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 662 }
 663
 664
 665 /*
 666  * Flush the READ FIFO on the Neo.
 667  *
 668  * NOTE: Channel lock MUST be held before calling this function!
 669  */
 670 static void neo_flush_uart_read(struct jsm_channel *ch)
 671 {
 672         u8 tmp = 0;
 673         int i = 0;
 674
 675         if (!ch)
 676                 return;
 677
 678         writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR), &ch->ch_neo_uart->isr_fcr);
 679
 680         for (i = 0; i < 10; i++) {
 681
 682                 /* Check to see if the UART feels it completely flushed the FIFO. */
 683                 tmp = readb(&ch->ch_neo_uart->isr_fcr);
 684                 if (tmp & 2) {
 685                         jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev,
 686                                         "Still flushing RX UART... i: %d\n", i);
 687                         udelay(10);
 688                 }
 689                 else
 690                         break;
 691         }
 692 }
 693
 694 /*
 695  * No locks are assumed to be held when calling this function.
 696  */
 697 static void neo_clear_break(struct jsm_channel *ch, int force)
 698 {
 699         unsigned long lock_flags;
 700
 701         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 702
 703         /* Turn break off, and unset some variables */
 704         if (ch->ch_flags & CH_BREAK_SENDING) {
 705                 u8 temp = readb(&ch->ch_neo_uart->lcr);
 706                 writeb((temp & ~UART_LCR_SBC), &ch->ch_neo_uart->lcr);
 707
 708                 ch->ch_flags &= ~(CH_BREAK_SENDING);
 709                 jsm_printk(IOCTL, INFO, &ch->ch_bd->pci_dev,
 710                                 "clear break Finishing UART_LCR_SBC! finished: %lx\n", jiffies);
 711
 712                 /* flush write operation */
 713                 neo_pci_posting_flush(ch->ch_bd);
 714         }
 715         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 716 }
 717
 718 /*
 719  * Parse the ISR register.
 720  */
 721 static inline void neo_parse_isr(struct jsm_board *brd, u32 port)
 722 {
 723         struct jsm_channel *ch;
 724         u8 isr;
 725         u8 cause;
 726         unsigned long lock_flags;
 727
 728         if (!brd)
 729                 return;
 730
 731         if (port > brd->maxports)
 732                 return;
 733
 734         ch = brd->channels[port];
 735         if (!ch)
 736                 return;
 737
 738         /* Here we try to figure out what caused the interrupt to happen */
 739         while (1) {
 740
 741                 isr = readb(&ch->ch_neo_uart->isr_fcr);
 742
 743                 /* Bail if no pending interrupt */
 744                 if (isr & UART_IIR_NO_INT)
 745                         break;
 746
 747                 /*
 748                  * Yank off the upper 2 bits, which just show that the FIFO's are enabled.
 749                  */
 750                 isr &= ~(UART_17158_IIR_FIFO_ENABLED);
 751
 752                 jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
 753                                 "%s:%d isr: %x\n", __FILE__, __LINE__, isr);
 754
 755                 if (isr & (UART_17158_IIR_RDI_TIMEOUT | UART_IIR_RDI)) {
 756                         /* Read data from uart -> queue */
 757                         neo_copy_data_from_uart_to_queue(ch);
 758
 759                         /* Call our tty layer to enforce queue flow control if needed. */
 760                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 761                         jsm_check_queue_flow_control(ch);
 762                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 763                 }
 764
 765                 if (isr & UART_IIR_THRI) {
 766                         /* Transfer data (if any) from Write Queue -> UART. */
 767                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 768                         ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 769                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 770                         neo_copy_data_from_queue_to_uart(ch);
 771                 }
 772
 773                 if (isr & UART_17158_IIR_XONXOFF) {
 774                         cause = readb(&ch->ch_neo_uart->xoffchar1);
 775
 776                         jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
 777                                         "Port %d. Got ISR_XONXOFF: cause:%x\n", port, cause);
 778
 779                         /*
 780                          * Since the UART detected either an XON or
 781                          * XOFF match, we need to figure out which
 782                          * one it was, so we can suspend or resume data flow.
 783                          */
 784                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 785                         if (cause == UART_17158_XON_DETECT) {
 786                                 /* Is output stopped right now, if so, resume it */
 787                                 if (brd->channels[port]->ch_flags & CH_STOP) {
 788                                         ch->ch_flags &= ~(CH_STOP);
 789                                 }
 790                                 jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
 791                                                 "Port %d. XON detected in incoming data\n", port);
 792                         }
 793                         else if (cause == UART_17158_XOFF_DETECT) {
 794                                 if (!(brd->channels[port]->ch_flags & CH_STOP)) {
 795                                         ch->ch_flags |= CH_STOP;
 796                                         jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
 797                                                         "Setting CH_STOP\n");
 798                                 }
 799                                 jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
 800                                                 "Port: %d. XOFF detected in incoming data\n", port);
 801                         }
 802                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 803                 }
 804
 805                 if (isr & UART_17158_IIR_HWFLOW_STATE_CHANGE) {
 806                         /*
 807                          * If we get here, this means the hardware is doing auto flow control.
 808                          * Check to see whether RTS/DTR or CTS/DSR caused this interrupt.
 809                          */
 810                         cause = readb(&ch->ch_neo_uart->mcr);
 811
 812                         /* Which pin is doing auto flow? RTS or DTR? */
 813                         spin_lock_irqsave(&ch->ch_lock, lock_flags);
 814                         if ((cause & 0x4) == 0) {
 815                                 if (cause & UART_MCR_RTS)
 816                                         ch->ch_mostat |= UART_MCR_RTS;
 817                                 else
 818                                         ch->ch_mostat &= ~(UART_MCR_RTS);
 819                         } else {
 820                                 if (cause & UART_MCR_DTR)
 821                                         ch->ch_mostat |= UART_MCR_DTR;
 822                                 else
 823                                         ch->ch_mostat &= ~(UART_MCR_DTR);
 824                         }
 825                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 826                 }
 827
 828                 /* Parse any modem signal changes */
 829                 jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
 830                                 "MOD_STAT: sending to parse_modem_sigs\n");
 831                 neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
 832         }
 833 }
 834
 835 static inline void neo_parse_lsr(struct jsm_board *brd, u32 port)
 836 {
 837         struct jsm_channel *ch;
 838         int linestatus;
 839         unsigned long lock_flags;
 840
 841         if (!brd)
 842                 return;
 843
 844         if (port > brd->maxports)
 845                 return;
 846
 847         ch = brd->channels[port];
 848         if (!ch)
 849                 return;
 850
 851         linestatus = readb(&ch->ch_neo_uart->lsr);
 852
 853         jsm_printk(INTR, INFO, &ch->ch_bd->pci_dev,
 854                         "%s:%d port: %d linestatus: %x\n", __FILE__, __LINE__, port, linestatus);
 855
 856         ch->ch_cached_lsr |= linestatus;
 857
 858         if (ch->ch_cached_lsr & UART_LSR_DR) {
 859                 /* Read data from uart -> queue */
 860                 neo_copy_data_from_uart_to_queue(ch);
 861                 spin_lock_irqsave(&ch->ch_lock, lock_flags);
 862                 jsm_check_queue_flow_control(ch);
 863                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 864         }
 865
 866         /*
 867          * This is a special flag. It indicates that at least 1
 868          * RX error (parity, framing, or break) has happened.
 869          * Mark this in our struct, which will tell me that I have
 870          *to do the special RX+LSR read for this FIFO load.
 871          */
 872         if (linestatus & UART_17158_RX_FIFO_DATA_ERROR)
 873                 jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
 874                         "%s:%d Port: %d Got an RX error, need to parse LSR\n",
 875                         __FILE__, __LINE__, port);
 876
 877         /*
 878          * The next 3 tests should *NOT* happen, as the above test
 879          * should encapsulate all 3... At least, thats what Exar says.
 880          */
 881
 882         if (linestatus & UART_LSR_PE) {
 883                 ch->ch_err_parity++;
 884                 jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
 885                         "%s:%d Port: %d. PAR ERR!\n", __FILE__, __LINE__, port);
 886         }
 887
 888         if (linestatus & UART_LSR_FE) {
 889                 ch->ch_err_frame++;
 890                 jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
 891                         "%s:%d Port: %d. FRM ERR!\n", __FILE__, __LINE__, port);
 892         }
 893
 894         if (linestatus & UART_LSR_BI) {
 895                 ch->ch_err_break++;
 896                 jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
 897                         "%s:%d Port: %d. BRK INTR!\n", __FILE__, __LINE__, port);
 898         }
 899
 900         if (linestatus & UART_LSR_OE) {
 901                 /*
 902                  * Rx Oruns. Exar says that an orun will NOT corrupt
 903                  * the FIFO. It will just replace the holding register
 904                  * with this new data byte. So basically just ignore this.
 905                  * Probably we should eventually have an orun stat in our driver...
 906                  */
 907                 ch->ch_err_overrun++;
 908                 jsm_printk(INTR, DEBUG, &ch->ch_bd->pci_dev,
 909                         "%s:%d Port: %d. Rx Overrun!\n", __FILE__, __LINE__, port);
 910         }
 911
 912         if (linestatus & UART_LSR_THRE) {
 913                 spin_lock_irqsave(&ch->ch_lock, lock_flags);
 914                 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 915                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 916
 917                 /* Transfer data (if any) from Write Queue -> UART. */
 918                 neo_copy_data_from_queue_to_uart(ch);
 919         }
 920         else if (linestatus & UART_17158_TX_AND_FIFO_CLR) {
 921                 spin_lock_irqsave(&ch->ch_lock, lock_flags);
 922                 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
 923                 spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
 924
 925                 /* Transfer data (if any) from Write Queue -> UART. */
 926                 neo_copy_data_from_queue_to_uart(ch);
 927         }
 928 }
 929
 930 /*
 931  * neo_param()
 932  * Send any/all changes to the line to the UART.
 933  */
 934 static void neo_param(struct jsm_channel *ch)
 935 {
 936         u8 lcr = 0;
 937         u8 uart_lcr = 0;
 938         u8 ier = 0;
 939         u32 baud = 9600;
 940         int quot = 0;
 941         struct jsm_board *bd;
 942
 943         bd = ch->ch_bd;
 944         if (!bd)
 945                 return;
 946
 947         /*
 948          * If baud rate is zero, flush queues, and set mval to drop DTR.
 949          */
 950         if ((ch->ch_c_cflag & (CBAUD)) == 0) {
 951                 ch->ch_r_head = ch->ch_r_tail = 0;
 952                 ch->ch_e_head = ch->ch_e_tail = 0;
 953                 ch->ch_w_head = ch->ch_w_tail = 0;
 954
 955                 neo_flush_uart_write(ch);
 956                 neo_flush_uart_read(ch);
 957
 958                 ch->ch_flags |= (CH_BAUD0);
 959                 ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
 960                 neo_assert_modem_signals(ch);
 961                 ch->ch_old_baud = 0;
 962                 return;
 963
 964         } else if (ch->ch_custom_speed) {
 965                         baud = ch->ch_custom_speed;
 966                         if (ch->ch_flags & CH_BAUD0)
 967                                 ch->ch_flags &= ~(CH_BAUD0);
 968         } else {
 969                 int i;
 970                 unsigned int cflag;
 971                 static struct {
 972                         unsigned int rate;
 973                         unsigned int cflag;
 974                 } baud_rates[] = {
 975                         { 921600, B921600 },
 976                         { 460800, B460800 },
 977                         { 230400, B230400 },
 978                         { 115200, B115200 },
 979                         {  57600, B57600  },
 980                         {  38400, B38400  },
 981                         {  19200, B19200  },
 982                         {   9600, B9600   },
 983                         {   4800, B4800   },
 984                         {   2400, B2400   },
 985                         {   1200, B1200   },
 986                         {    600, B600    },
 987                         {    300, B300    },
 988                         {    200, B200    },
 989                         {    150, B150    },
 990                         {    134, B134    },
 991                         {    110, B110    },
 992                         {     75, B75     },
 993                         {     50, B50     },
 994                 };
 995
 996                 cflag = C_BAUD(ch->uart_port.info->tty);
 997                 baud = 9600;
 998                 for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
 999                         if (baud_rates[i].cflag == cflag) {
1000                                 baud = baud_rates[i].rate;
1001                                 break;
1002                         }
1003                 }
1004
1005                 if (ch->ch_flags & CH_BAUD0)
1006                         ch->ch_flags &= ~(CH_BAUD0);
1007         }
1008
1009         if (ch->ch_c_cflag & PARENB)
1010                 lcr |= UART_LCR_PARITY;
1011
1012         if (!(ch->ch_c_cflag & PARODD))
1013                 lcr |= UART_LCR_EPAR;
1014
1015         /*
1016          * Not all platforms support mark/space parity,
1017          * so this will hide behind an ifdef.
1018          */
1019 #ifdef CMSPAR
1020         if (ch->ch_c_cflag & CMSPAR)
1021                 lcr |= UART_LCR_SPAR;
1022 #endif
1023
1024         if (ch->ch_c_cflag & CSTOPB)
1025                 lcr |= UART_LCR_STOP;
1026
1027         switch (ch->ch_c_cflag & CSIZE) {
1028                 case CS5:
1029                         lcr |= UART_LCR_WLEN5;
1030                         break;
1031                 case CS6:
1032                         lcr |= UART_LCR_WLEN6;
1033                         break;
1034                 case CS7:
1035                         lcr |= UART_LCR_WLEN7;
1036                         break;
1037                 case CS8:
1038                 default:
1039                         lcr |= UART_LCR_WLEN8;
1040                 break;
1041         }
1042
1043         ier = readb(&ch->ch_neo_uart->ier);
1044         uart_lcr = readb(&ch->ch_neo_uart->lcr);
1045
1046         if (baud == 0)
1047                 baud = 9600;
1048
1049         quot = ch->ch_bd->bd_dividend / baud;
1050
1051         if (quot != 0) {
1052                 ch->ch_old_baud = baud;
1053                 writeb(UART_LCR_DLAB, &ch->ch_neo_uart->lcr);
1054                 writeb((quot & 0xff), &ch->ch_neo_uart->txrx);
1055                 writeb((quot >> 8), &ch->ch_neo_uart->ier);
1056                 writeb(lcr, &ch->ch_neo_uart->lcr);
1057         }
1058
1059         if (uart_lcr != lcr)
1060                 writeb(lcr, &ch->ch_neo_uart->lcr);
1061
1062         if (ch->ch_c_cflag & CREAD)
1063                 ier |= (UART_IER_RDI | UART_IER_RLSI);
1064
1065         ier |= (UART_IER_THRI | UART_IER_MSI);
1066
1067         writeb(ier, &ch->ch_neo_uart->ier);
1068
1069         /* Set new start/stop chars */
1070         neo_set_new_start_stop_chars(ch);
1071
1072         if (ch->ch_c_cflag & CRTSCTS)
1073                 neo_set_cts_flow_control(ch);
1074         else if (ch->ch_c_iflag & IXON) {
1075                 /* If start/stop is set to disable, then we should disable flow control */
1076                 if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1077                         neo_set_no_output_flow_control(ch);
1078                 else
1079                         neo_set_ixon_flow_control(ch);
1080         }
1081         else
1082                 neo_set_no_output_flow_control(ch);
1083
1084         if (ch->ch_c_cflag & CRTSCTS)
1085                 neo_set_rts_flow_control(ch);
1086         else if (ch->ch_c_iflag & IXOFF) {
1087                 /* If start/stop is set to disable, then we should disable flow control */
1088                 if ((ch->ch_startc == __DISABLED_CHAR) || (ch->ch_stopc == __DISABLED_CHAR))
1089                         neo_set_no_input_flow_control(ch);
1090                 else
1091                         neo_set_ixoff_flow_control(ch);
1092         }
1093         else
1094                 neo_set_no_input_flow_control(ch);
1095         /*
1096          * Adjust the RX FIFO Trigger level if baud is less than 9600.
1097          * Not exactly elegant, but this is needed because of the Exar chip's
1098          * delay on firing off the RX FIFO interrupt on slower baud rates.
1099          */
1100         if (baud < 9600) {
1101                 writeb(1, &ch->ch_neo_uart->rfifo);
1102                 ch->ch_r_tlevel = 1;
1103         }
1104
1105         neo_assert_modem_signals(ch);
1106
1107         /* Get current status of the modem signals now */
1108         neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
1109         return;
1110 }
1111
1112 /*
1113  * jsm_neo_intr()
1114  *
1115  * Neo specific interrupt handler.
1116  */
1117 static irqreturn_t neo_intr(int irq, void *voidbrd)
1118 {
1119         struct jsm_board *brd = voidbrd;
1120         struct jsm_channel *ch;
1121         int port = 0;
1122         int type = 0;
1123         int current_port;
1124         u32 tmp;
1125         u32 uart_poll;
1126         unsigned long lock_flags;
1127         unsigned long lock_flags2;
1128         int outofloop_count = 0;
1129
1130         brd->intr_count++;
1131
1132         /* Lock out the slow poller from running on this board. */
1133         spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
1134
1135         /*
1136          * Read in "extended" IRQ information from the 32bit Neo register.
1137          * Bits 0-7: What port triggered the interrupt.
1138          * Bits 8-31: Each 3bits indicate what type of interrupt occurred.
1139          */
1140         uart_poll = readl(brd->re_map_membase + UART_17158_POLL_ADDR_OFFSET);
1141
1142         jsm_printk(INTR, INFO, &brd->pci_dev,
1143                 "%s:%d uart_poll: %x\n", __FILE__, __LINE__, uart_poll);
1144
1145         if (!uart_poll) {
1146                 jsm_printk(INTR, INFO, &brd->pci_dev,
1147                         "Kernel interrupted to me, but no pending interrupts...\n");
1148                 spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1149                 return IRQ_NONE;
1150         }
1151
1152         /* At this point, we have at least SOMETHING to service, dig further... */
1153
1154         current_port = 0;
1155
1156         /* Loop on each port */
1157         while (((uart_poll & 0xff) != 0) && (outofloop_count < 0xff)){
1158
1159                 tmp = uart_poll;
1160                 outofloop_count++;
1161
1162                 /* Check current port to see if it has interrupt pending */
1163                 if ((tmp & jsm_offset_table[current_port]) != 0) {
1164                         port = current_port;
1165                         type = tmp >> (8 + (port * 3));
1166                         type &= 0x7;
1167                 } else {
1168                         current_port++;
1169                         continue;
1170                 }
1171
1172                 jsm_printk(INTR, INFO, &brd->pci_dev,
1173                 "%s:%d port: %x type: %x\n", __FILE__, __LINE__, port, type);
1174
1175                 /* Remove this port + type from uart_poll */
1176                 uart_poll &= ~(jsm_offset_table[port]);
1177
1178                 if (!type) {
1179                         /* If no type, just ignore it, and move onto next port */
1180                         jsm_printk(INTR, ERR, &brd->pci_dev,
1181                                 "Interrupt with no type! port: %d\n", port);
1182                         continue;
1183                 }
1184
1185                 /* Switch on type of interrupt we have */
1186                 switch (type) {
1187
1188                 case UART_17158_RXRDY_TIMEOUT:
1189                         /*
1190                          * RXRDY Time-out is cleared by reading data in the
1191                         * RX FIFO until it falls below the trigger level.
1192                          */
1193
1194                         /* Verify the port is in range. */
1195                         if (port > brd->nasync)
1196                                 continue;
1197
1198                         ch = brd->channels[port];
1199                         neo_copy_data_from_uart_to_queue(ch);
1200
1201                         /* Call our tty layer to enforce queue flow control if needed. */
1202                         spin_lock_irqsave(&ch->ch_lock, lock_flags2);
1203                         jsm_check_queue_flow_control(ch);
1204                         spin_unlock_irqrestore(&ch->ch_lock, lock_flags2);
1205
1206                         continue;
1207
1208                 case UART_17158_RX_LINE_STATUS:
1209                         /*
1210                          * RXRDY and RX LINE Status (logic OR of LSR[4:1])
1211                          */
1212                         neo_parse_lsr(brd, port);
1213                         continue;
1214
1215                 case UART_17158_TXRDY:
1216                         /*
1217                          * TXRDY interrupt clears after reading ISR register for the UART channel.
1218                          */
1219
1220                         /*
1221                          * Yes, this is odd...
1222                          * Why would I check EVERY possibility of type of
1223                          * interrupt, when we know its TXRDY???
1224                          * Becuz for some reason, even tho we got triggered for TXRDY,
1225                          * it seems to be occassionally wrong. Instead of TX, which
1226                          * it should be, I was getting things like RXDY too. Weird.
1227                          */
1228                         neo_parse_isr(brd, port);
1229                         continue;
1230
1231                 case UART_17158_MSR:
1232                         /*
1233                          * MSR or flow control was seen.
1234                          */
1235                         neo_parse_isr(brd, port);
1236                         continue;
1237
1238                 default:
1239                         /*
1240                          * The UART triggered us with a bogus interrupt type.
1241                          * It appears the Exar chip, when REALLY bogged down, will throw
1242                          * these once and awhile.
1243                          * Its harmless, just ignore it and move on.
1244                          */
1245                         jsm_printk(INTR, ERR, &brd->pci_dev,
1246                                 "%s:%d Unknown Interrupt type: %x\n", __FILE__, __LINE__, type);
1247                         continue;
1248                 }
1249         }
1250
1251         spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
1252
1253         jsm_printk(INTR, INFO, &brd->pci_dev, "finish.\n");
1254         return IRQ_HANDLED;
1255 }
1256
1257 /*
1258  * Neo specific way of turning off the receiver.
1259  * Used as a way to enforce queue flow control when in
1260  * hardware flow control mode.
1261  */
1262 static void neo_disable_receiver(struct jsm_channel *ch)
1263 {
1264         u8 tmp = readb(&ch->ch_neo_uart->ier);
1265         tmp &= ~(UART_IER_RDI);
1266         writeb(tmp, &ch->ch_neo_uart->ier);
1267
1268         /* flush write operation */
1269         neo_pci_posting_flush(ch->ch_bd);
1270 }
1271
1272
1273 /*
1274  * Neo specific way of turning on the receiver.
1275  * Used as a way to un-enforce queue flow control when in
1276  * hardware flow control mode.
1277  */
1278 static void neo_enable_receiver(struct jsm_channel *ch)
1279 {
1280         u8 tmp = readb(&ch->ch_neo_uart->ier);
1281         tmp |= (UART_IER_RDI);
1282         writeb(tmp, &ch->ch_neo_uart->ier);
1283
1284         /* flush write operation */
1285         neo_pci_posting_flush(ch->ch_bd);
1286 }
1287
1288 static void neo_send_start_character(struct jsm_channel *ch)
1289 {
1290         if (!ch)
1291                 return;
1292
1293         if (ch->ch_startc != __DISABLED_CHAR) {
1294                 ch->ch_xon_sends++;
1295                 writeb(ch->ch_startc, &ch->ch_neo_uart->txrx);
1296
1297                 /* flush write operation */
1298                 neo_pci_posting_flush(ch->ch_bd);
1299         }
1300 }
1301
1302 static void neo_send_stop_character(struct jsm_channel *ch)
1303 {
1304         if (!ch)
1305                 return;
1306
1307         if (ch->ch_stopc != __DISABLED_CHAR) {
1308                 ch->ch_xoff_sends++;
1309                 writeb(ch->ch_stopc, &ch->ch_neo_uart->txrx);
1310
1311                 /* flush write operation */
1312                 neo_pci_posting_flush(ch->ch_bd);
1313         }
1314 }
1315
1316 /*
1317  * neo_uart_init
1318  */
1319 static void neo_uart_init(struct jsm_channel *ch)
1320 {
1321         writeb(0, &ch->ch_neo_uart->ier);
1322         writeb(0, &ch->ch_neo_uart->efr);
1323         writeb(UART_EFR_ECB, &ch->ch_neo_uart->efr);
1324
1325         /* Clear out UART and FIFO */
1326         readb(&ch->ch_neo_uart->txrx);
1327         writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT), &ch->ch_neo_uart->isr_fcr);
1328         readb(&ch->ch_neo_uart->lsr);
1329         readb(&ch->ch_neo_uart->msr);
1330
1331         ch->ch_flags |= CH_FIFO_ENABLED;
1332
1333         /* Assert any signals we want up */
1334         writeb(ch->ch_mostat, &ch->ch_neo_uart->mcr);
1335 }
1336
1337 /*
1338  * Make the UART completely turn off.
1339  */
1340 static void neo_uart_off(struct jsm_channel *ch)
1341 {
1342         /* Turn off UART enhanced bits */
1343         writeb(0, &ch->ch_neo_uart->efr);
1344
1345         /* Stop all interrupts from occurring. */
1346         writeb(0, &ch->ch_neo_uart->ier);
1347 }
1348
1349 static u32 neo_get_uart_bytes_left(struct jsm_channel *ch)
1350 {
1351         u8 left = 0;
1352         u8 lsr = readb(&ch->ch_neo_uart->lsr);
1353
1354         /* We must cache the LSR as some of the bits get reset once read... */
1355         ch->ch_cached_lsr |= lsr;
1356
1357         /* Determine whether the Transmitter is empty or not */
1358         if (!(lsr & UART_LSR_TEMT))
1359                 left = 1;
1360         else {
1361                 ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
1362                 left = 0;
1363         }
1364
1365         return left;
1366 }
1367
1368 /* Channel lock MUST be held by the calling function! */
1369 static void neo_send_break(struct jsm_channel *ch)
1370 {
1371         /*
1372          * Set the time we should stop sending the break.
1373          * If we are already sending a break, toss away the existing
1374          * time to stop, and use this new value instead.
1375          */
1376
1377         /* Tell the UART to start sending the break */
1378         if (!(ch->ch_flags & CH_BREAK_SENDING)) {
1379                 u8 temp = readb(&ch->ch_neo_uart->lcr);
1380                 writeb((temp | UART_LCR_SBC), &ch->ch_neo_uart->lcr);
1381                 ch->ch_flags |= (CH_BREAK_SENDING);
1382
1383                 /* flush write operation */
1384                 neo_pci_posting_flush(ch->ch_bd);
1385         }
1386 }
1387
1388 /*
1389  * neo_send_immediate_char.
1390  *
1391  * Sends a specific character as soon as possible to the UART,
1392  * jumping over any bytes that might be in the write queue.
1393  *
1394  * The channel lock MUST be held by the calling function.
1395  */
1396 static void neo_send_immediate_char(struct jsm_channel *ch, unsigned char c)
1397 {
1398         if (!ch)
1399                 return;
1400
1401         writeb(c, &ch->ch_neo_uart->txrx);
1402
1403         /* flush write operation */
1404         neo_pci_posting_flush(ch->ch_bd);
1405 }
1406
1407 struct board_ops jsm_neo_ops = {
1408         .intr                           = neo_intr,
1409         .uart_init                      = neo_uart_init,
1410         .uart_off                       = neo_uart_off,
1411         .param                          = neo_param,
1412         .assert_modem_signals           = neo_assert_modem_signals,
1413         .flush_uart_write               = neo_flush_uart_write,
1414         .flush_uart_read                = neo_flush_uart_read,
1415         .disable_receiver               = neo_disable_receiver,
1416         .enable_receiver                = neo_enable_receiver,
1417         .send_break                     = neo_send_break,
1418         .clear_break                    = neo_clear_break,
1419         .send_start_character           = neo_send_start_character,
1420         .send_stop_character            = neo_send_stop_character,
1421         .copy_data_from_queue_to_uart   = neo_copy_data_from_queue_to_uart,
1422         .get_uart_bytes_left            = neo_get_uart_bytes_left,
1423         .send_immediate_char            = neo_send_immediate_char
1424 };