sys/bus/iicbus/i386/pcf.c

   1 /*-
   2  * Copyright (c) 1998 Nicolas Souchu, Marc Bouget
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sys/i386/isa/pcf.c,v 1.14 2000/01/14 00:18:05 nsouch Exp $
  27  * $DragonFly: src/sys/bus/iicbus/i386/pcf.c,v 1.11 2008/08/02 01:14:38 dillon Exp $
  28  *
  29  */
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/kernel.h>
  33 #include <sys/module.h>
  34 #include <sys/bus.h>
  35 #include <sys/malloc.h>
  36
  37 #include <machine/clock.h>
  38 #include <sys/rman.h>
  39
  40 #include <bus/isa/isareg.h>
  41 #include <bus/isa/isavar.h>
  42
  43 #include <bus/isa/isa_device.h>
  44
  45 #include "../iiconf.h"
  46 #include "iicbus_if.h"
  47
  48 #define IO_PCFSIZE      2
  49
  50 #define TIMEOUT 9999                                    /* XXX */
  51
  52 /* Status bits of S1 register (read only) */
  53 #define nBB     0x01            /* busy when low set/reset by STOP/START*/
  54 #define LAB     0x02            /* lost arbitration bit in multi-master mode */
  55 #define AAS     0x04            /* addressed as slave */
  56 #define LRB     0x08            /* last received byte when not AAS */
  57 #define AD0     0x08            /* general call received when AAS */
  58 #define BER     0x10            /* bus error, misplaced START or STOP */
  59 #define STS     0x20            /* STOP detected in slave receiver mode */
  60 #define PIN     0x80            /* pending interrupt not (r/w) */
  61
  62 /* Control bits of S1 register (write only) */
  63 #define ACK     0x01
  64 #define STO     0x02
  65 #define STA     0x04
  66 #define ENI     0x08
  67 #define ES2     0x10
  68 #define ES1     0x20
  69 #define ES0     0x40
  70
  71 #define BUFSIZE 2048
  72
  73 #define SLAVE_TRANSMITTER       0x1
  74 #define SLAVE_RECEIVER          0x2
  75
  76 #define PCF_DEFAULT_ADDR        0xaa
  77
  78 struct pcf_softc {
  79
  80         int pcf_base;                   /* isa port */
  81         int pcf_flags;
  82         u_char pcf_addr;                /* interface I2C address */
  83
  84         int pcf_slave_mode;             /* receiver or transmitter */
  85         int pcf_started;                /* 1 if start condition sent */
  86
  87         device_t iicbus;                /* the corresponding iicbus */
  88
  89         int rid_irq, rid_ioport;
  90         struct resource *res_irq, *res_ioport;
  91         void *intr_cookie;
  92 };
  93
  94 static int pcf_probe(device_t);
  95 static int pcf_attach(device_t);
  96 static void pcfintr(void *arg);
  97
  98 static int pcf_print_child(device_t, device_t);
  99
 100 static int pcf_repeated_start(device_t, u_char, int);
 101 static int pcf_start(device_t, u_char, int);
 102 static int pcf_stop(device_t);
 103 static int pcf_write(device_t, const char *, int, int *, int);
 104 static int pcf_read(device_t, char *, int, int *, int, int);
 105 static int pcf_rst_card(device_t, u_char, u_char, u_char *);
 106
 107 static device_method_t pcf_methods[] = {
 108         /* device interface */
 109         DEVMETHOD(device_probe,         pcf_probe),
 110         DEVMETHOD(device_attach,        pcf_attach),
 111
 112         /* bus interface */
 113         DEVMETHOD(bus_print_child,      pcf_print_child),
 114
 115         /* iicbus interface */
 116         DEVMETHOD(iicbus_callback,      iicbus_null_callback),
 117         DEVMETHOD(iicbus_repeated_start, pcf_repeated_start),
 118         DEVMETHOD(iicbus_start,         pcf_start),
 119         DEVMETHOD(iicbus_stop,          pcf_stop),
 120         DEVMETHOD(iicbus_write,         pcf_write),
 121         DEVMETHOD(iicbus_read,          pcf_read),
 122         DEVMETHOD(iicbus_reset,         pcf_rst_card),
 123
 124         { 0, 0 }
 125 };
 126
 127 static driver_t pcf_driver = {
 128         "pcf",
 129         pcf_methods,
 130         sizeof(struct pcf_softc),
 131 };
 132
 133 static devclass_t pcf_devclass;
 134
 135 #define DEVTOSOFTC(dev) ((struct pcf_softc *)device_get_softc(dev))
 136
 137 static int
 138 pcf_probe(device_t pcfdev)
 139 {
 140         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 141         device_t parent = device_get_parent(pcfdev);
 142
 143         device_set_desc(pcfdev, "PCF8584 I2C bus controller");
 144
 145         bzero(pcf, sizeof(struct pcf_softc));
 146
 147         pcf->rid_irq = pcf->rid_ioport = 0;
 148         pcf->res_irq = pcf->res_ioport = 0;
 149
 150         /* IO port is mandatory */
 151         pcf->res_ioport = bus_alloc_resource(pcfdev, SYS_RES_IOPORT,
 152                                              &pcf->rid_ioport, 0ul, ~0ul,
 153                                              IO_PCFSIZE, RF_ACTIVE);
 154         if (pcf->res_ioport == 0) {
 155                 device_printf(pcfdev, "cannot reserve I/O port range\n");
 156                 goto error;
 157         }
 158         BUS_READ_IVAR(parent, pcfdev, ISA_IVAR_PORT, &pcf->pcf_base);
 159
 160         pcf->pcf_flags = device_get_flags(pcfdev);
 161
 162         if (!(pcf->pcf_flags & IIC_POLLED)) {
 163                 pcf->res_irq = bus_alloc_resource(pcfdev, SYS_RES_IRQ, &pcf->rid_irq,
 164                                                   0ul, ~0ul, 1, RF_ACTIVE);
 165                 if (pcf->res_irq == 0) {
 166                         device_printf(pcfdev, "can't reserve irq, polled mode.\n");
 167                         pcf->pcf_flags |= IIC_POLLED;
 168                 }
 169         }
 170
 171         /* reset the chip */
 172         pcf_rst_card(pcfdev, IIC_FASTEST, PCF_DEFAULT_ADDR, NULL);
 173
 174         return (0);
 175 error:
 176         if (pcf->res_ioport != 0) {
 177                 bus_deactivate_resource(pcfdev, SYS_RES_IOPORT, pcf->rid_ioport,
 178                                         pcf->res_ioport);
 179                 bus_release_resource(pcfdev, SYS_RES_IOPORT, pcf->rid_ioport,
 180                                      pcf->res_ioport);
 181         }
 182         return (ENXIO);
 183 }
 184
 185 static int
 186 pcf_attach(device_t pcfdev)
 187 {
 188         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 189         device_t parent = device_get_parent(pcfdev);
 190         int error = 0;
 191
 192         if (pcf->res_irq) {
 193                 /* default to the tty mask for registration */  /* XXX */
 194                 error = BUS_SETUP_INTR(parent, pcfdev, pcf->res_irq,
 195                                         0, pcfintr, pcfdev,
 196                                         &pcf->intr_cookie, NULL);
 197                 if (error)
 198                         return (error);
 199         }
 200
 201         pcf->iicbus = iicbus_alloc_bus(pcfdev);
 202
 203         /* probe and attach the iicbus */
 204         device_probe_and_attach(pcf->iicbus);
 205
 206         return (0);
 207 }
 208
 209 static int
 210 pcf_print_child(device_t bus, device_t dev)
 211 {
 212         struct pcf_softc *pcf = (struct pcf_softc *)device_get_softc(bus);
 213         int retval = 0;
 214
 215         retval += bus_print_child_header(bus, dev);
 216         retval += kprintf(" on %s addr 0x%x\n", device_get_nameunit(bus),
 217                          (int)pcf->pcf_addr);
 218
 219         return (retval);
 220 }
 221
 222 /*
 223  * PCF8584 datasheet : when operate at 8 MHz or more, a minimun time of
 224  * 6 clocks cycles must be left between two consecutives access
 225  */
 226 #define pcf_nops()      DELAY(10)
 227
 228 #define dummy_read(pcf)         PCF_GET_S0(pcf)
 229 #define dummy_write(pcf)        PCF_SET_S0(pcf, 0)
 230
 231 /*
 232  * Specific register access to PCF8584
 233  */
 234 static void
 235 PCF_SET_S0(struct pcf_softc *pcf, int data)
 236 {
 237         outb(pcf->pcf_base, data);
 238         pcf_nops();
 239 }
 240
 241 static void
 242 PCF_SET_S1(struct pcf_softc *pcf, int data)
 243 {
 244         outb(pcf->pcf_base+1, data);
 245         pcf_nops();
 246 }
 247
 248 static char
 249 PCF_GET_S0(struct pcf_softc *pcf)
 250 {
 251         char data;
 252
 253         data = inb(pcf->pcf_base);
 254         pcf_nops();
 255
 256         return (data);
 257 }
 258
 259 static char
 260 PCF_GET_S1(struct pcf_softc *pcf)
 261 {
 262         char data;
 263
 264         data = inb(pcf->pcf_base+1);
 265         pcf_nops();
 266
 267         return (data);
 268 }
 269
 270 /*
 271  * Polling mode for master operations wait for a new
 272  * byte incomming or outgoing
 273  */
 274 static int
 275 pcf_wait_byte(struct pcf_softc *pcf)
 276 {
 277         int counter = TIMEOUT;
 278
 279         while (counter--) {
 280
 281                 if ((PCF_GET_S1(pcf) & PIN) == 0)
 282                         return (0);
 283         }
 284
 285         return (IIC_ETIMEOUT);
 286 }
 287
 288 static int
 289 pcf_stop(device_t pcfdev)
 290 {
 291         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 292
 293         /*
 294          * Send STOP condition iff the START condition was previously sent.
 295          * STOP is sent only once even if a iicbus_stop() is called after
 296          * an iicbus_read()... see pcf_read(): the pcf needs to send the stop
 297          * before the last char is read.
 298          */
 299         if (pcf->pcf_started) {
 300                 /* set stop condition and enable IT */
 301                 PCF_SET_S1(pcf, PIN|ES0|ENI|STO|ACK);
 302
 303                 pcf->pcf_started = 0;
 304         }
 305
 306         return (0);
 307 }
 308
 309
 310 static int
 311 pcf_noack(struct pcf_softc *pcf, int timeout)
 312 {
 313         int noack;
 314         int k = timeout/10;
 315
 316         do {
 317                 noack = PCF_GET_S1(pcf) & LRB;
 318                 if (!noack)
 319                         break;
 320                 DELAY(10);                              /* XXX wait 10 us */
 321         } while (k--);
 322
 323         return (noack);
 324 }
 325
 326 static int
 327 pcf_repeated_start(device_t pcfdev, u_char slave, int timeout)
 328 {
 329         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 330         int error = 0;
 331
 332         /* repeated start */
 333         PCF_SET_S1(pcf, ES0|STA|STO|ACK);
 334
 335         /* set slave address to PCF. Last bit (LSB) must be set correctly
 336          * according to transfer direction */
 337         PCF_SET_S0(pcf, slave);
 338
 339         /* wait for address sent, polling */
 340         if ((error = pcf_wait_byte(pcf)))
 341                 goto error;
 342
 343         /* check for ack */
 344         if (pcf_noack(pcf, timeout)) {
 345                 error = IIC_ENOACK;
 346                 goto error;
 347         }
 348
 349         return (0);
 350
 351 error:
 352         pcf_stop(pcfdev);
 353         return (error);
 354 }
 355
 356 static int
 357 pcf_start(device_t pcfdev, u_char slave, int timeout)
 358 {
 359         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 360         int error = 0;
 361
 362         if ((PCF_GET_S1(pcf) & nBB) == 0)
 363                 return (IIC_EBUSBSY);
 364
 365         /* set slave address to PCF. Last bit (LSB) must be set correctly
 366          * according to transfer direction */
 367         PCF_SET_S0(pcf, slave);
 368
 369         /* START only */
 370         PCF_SET_S1(pcf, PIN|ES0|STA|ACK);
 371
 372         pcf->pcf_started = 1;
 373
 374         /* wait for address sent, polling */
 375         if ((error = pcf_wait_byte(pcf)))
 376                 goto error;
 377
 378         /* check for ACK */
 379         if (pcf_noack(pcf, timeout)) {
 380                 error = IIC_ENOACK;
 381                 goto error;
 382         }
 383
 384         return (0);
 385
 386 error:
 387         pcf_stop(pcfdev);
 388         return (error);
 389 }
 390
 391 static void
 392 pcfintr(void *arg)
 393 {
 394         device_t pcfdev = (device_t)arg;
 395         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 396
 397         char data, status, addr;
 398         char error = 0;
 399
 400         status = PCF_GET_S1(pcf);
 401
 402         if (status & PIN) {
 403                 device_printf(pcfdev, "spurious interrupt, status=0x%x\n", status & 0xff);
 404
 405                 goto error;
 406         }
 407
 408         if (status & LAB)
 409                 device_printf(pcfdev, "bus arbitration lost!\n");
 410
 411         if (status & BER) {
 412                 error = IIC_EBUSERR;
 413                 iicbus_intr(pcf->iicbus, INTR_ERROR, &error);
 414
 415                 goto error;
 416         }
 417
 418         do {
 419                 status = PCF_GET_S1(pcf);
 420
 421                 switch(pcf->pcf_slave_mode) {
 422
 423                 case SLAVE_TRANSMITTER:
 424                         if (status & LRB) {
 425                                 /* ack interrupt line */
 426                                 dummy_write(pcf);
 427
 428                                 /* no ack, don't send anymore */
 429                                 pcf->pcf_slave_mode = SLAVE_RECEIVER;
 430
 431                                 iicbus_intr(pcf->iicbus, INTR_NOACK, NULL);
 432                                 break;
 433                         }
 434
 435                         /* get data from upper code */
 436                         iicbus_intr(pcf->iicbus, INTR_TRANSMIT, &data);
 437
 438                         PCF_SET_S0(pcf, data);
 439                         break;
 440
 441                 case SLAVE_RECEIVER:
 442                         if (status & AAS) {
 443                                 addr = PCF_GET_S0(pcf);
 444
 445                                 if (status & AD0)
 446                                         iicbus_intr(pcf->iicbus, INTR_GENERAL, &addr);
 447                                 else
 448                                         iicbus_intr(pcf->iicbus, INTR_START, &addr);
 449
 450                                 if (addr & LSB) {
 451                                         pcf->pcf_slave_mode = SLAVE_TRANSMITTER;
 452
 453                                         /* get the first char from upper code */
 454                                         iicbus_intr(pcf->iicbus, INTR_TRANSMIT, &data);
 455
 456                                         /* send first data byte */
 457                                         PCF_SET_S0(pcf, data);
 458                                 }
 459
 460                                 break;
 461                         }
 462
 463                         /* stop condition received? */
 464                         if (status & STS) {
 465                                 /* ack interrupt line */
 466                                 dummy_read(pcf);
 467
 468                                 /* emulate intr stop condition */
 469                                 iicbus_intr(pcf->iicbus, INTR_STOP, NULL);
 470
 471                         } else {
 472                                 /* get data, ack interrupt line */
 473                                 data = PCF_GET_S0(pcf);
 474
 475                                 /* deliver the character */
 476                                 iicbus_intr(pcf->iicbus, INTR_RECEIVE, &data);
 477                         }
 478                         break;
 479
 480                     default:
 481                         panic("%s: unknown slave mode (%d)!", __func__,
 482                                 pcf->pcf_slave_mode);
 483                     }
 484
 485         } while ((PCF_GET_S1(pcf) & PIN) == 0);
 486
 487         return;
 488
 489 error:
 490         /* unknown event on bus...reset PCF */
 491         PCF_SET_S1(pcf, PIN|ES0|ENI|ACK);
 492
 493         pcf->pcf_slave_mode = SLAVE_RECEIVER;
 494
 495         return;
 496 }
 497
 498 static int
 499 pcf_rst_card(device_t pcfdev, u_char speed, u_char addr, u_char *oldaddr)
 500 {
 501         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 502
 503         if (oldaddr)
 504                 *oldaddr = pcf->pcf_addr;
 505
 506         /* retrieve own address from bus level */
 507         if (!addr)
 508                 pcf->pcf_addr = PCF_DEFAULT_ADDR;
 509         else
 510                 pcf->pcf_addr = addr;
 511
 512         PCF_SET_S1(pcf, PIN);                           /* initialize S1 */
 513
 514         /* own address S'O<>0 */
 515         PCF_SET_S0(pcf, pcf->pcf_addr >> 1);
 516
 517         /* select clock register */
 518         PCF_SET_S1(pcf, PIN|ES1);
 519
 520         /* select bus speed : 18=90kb, 19=45kb, 1A=11kb, 1B=1.5kb */
 521         switch (speed) {
 522         case IIC_SLOW:
 523                 PCF_SET_S0(pcf,  0x1b);
 524                 break;
 525
 526         case IIC_FAST:
 527                 PCF_SET_S0(pcf,  0x19);
 528                 break;
 529
 530         case IIC_UNKNOWN:
 531         case IIC_FASTEST:
 532         default:
 533                 PCF_SET_S0(pcf,  0x18);
 534                 break;
 535         }
 536
 537         /* set bus on, ack=yes, INT=yes */
 538         PCF_SET_S1(pcf, PIN|ES0|ENI|ACK);
 539
 540         pcf->pcf_slave_mode = SLAVE_RECEIVER;
 541
 542         return (0);
 543 }
 544
 545 static int
 546 pcf_write(device_t pcfdev, const char *buf, int len, int *sent,
 547           int timeout /* us */)
 548 {
 549         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 550         int bytes, error = 0;
 551
 552 #ifdef PCFDEBUG
 553         kprintf("pcf%d: >> writing %d bytes\n", device_get_unit(pcfdev), len);
 554 #endif
 555
 556         bytes = 0;
 557         while (len) {
 558
 559                 PCF_SET_S0(pcf, *buf++);
 560
 561                 /* wait for the byte to be send */
 562                 if ((error = pcf_wait_byte(pcf)))
 563                         goto error;
 564
 565                 /* check if ack received */
 566                 if (pcf_noack(pcf, timeout)) {
 567                         error = IIC_ENOACK;
 568                         goto error;
 569                 }
 570
 571                 len --;
 572                 bytes ++;
 573         }
 574
 575 error:
 576         *sent = bytes;
 577
 578 #ifdef PCFDEBUG
 579         kprintf("pcf%d: >> %d bytes written (%d)\n",
 580                 device_get_unit(pcfdev), bytes, error);
 581 #endif
 582
 583         return (error);
 584 }
 585
 586 static int
 587 pcf_read(device_t pcfdev, char *buf, int len, int *read, int last,
 588                                                         int delay /* us */)
 589 {
 590         struct pcf_softc *pcf = DEVTOSOFTC(pcfdev);
 591         int bytes, error = 0;
 592
 593 #ifdef PCFDEBUG
 594         kprintf("pcf%d: << reading %d bytes\n", device_get_unit(pcfdev), len);
 595 #endif
 596
 597         /* trig the bus to get the first data byte in S0 */
 598         if (len) {
 599                 if (len == 1 && last)
 600                         /* just one byte to read */
 601                         PCF_SET_S1(pcf, ES0);           /* no ack */
 602
 603                 dummy_read(pcf);
 604         }
 605
 606         bytes = 0;
 607         while (len) {
 608
 609                 /* XXX delay needed here */
 610
 611                 /* wait for trigged byte */
 612                 if ((error = pcf_wait_byte(pcf))) {
 613                         pcf_stop(pcfdev);
 614                         goto error;
 615                 }
 616
 617                 if (len == 1 && last)
 618                         /* ok, last data byte already in S0, no I2C activity
 619                          * on next PCF_GET_S0() */
 620                         pcf_stop(pcfdev);
 621
 622                 else if (len == 2 && last)
 623                         /* next trigged byte with no ack */
 624                         PCF_SET_S1(pcf, ES0);
 625
 626                 /* receive byte, trig next byte */
 627                 *buf++ = PCF_GET_S0(pcf);
 628
 629                 len --;
 630                 bytes ++;
 631         };
 632
 633 error:
 634         *read = bytes;
 635
 636 #ifdef PCFDEBUG
 637         kprintf("pcf%d: << %d bytes read (%d)\n",
 638                 device_get_unit(pcfdev), bytes, error);
 639 #endif
 640
 641         return (error);
 642 }
 643
 644 DRIVER_MODULE(pcf, isa, pcf_driver, pcf_devclass, 0, 0);