pcf.c revision 87599
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: head/sys/dev/pcf/pcf.c 87599 2001-12-10 08:09:49Z obrien $ 27 * 28 */ 29#include <sys/param.h> 30#include <sys/systm.h> 31#include <sys/kernel.h> 32#include <sys/module.h> 33#include <sys/bus.h> 34 35#include <machine/bus.h> 36#include <machine/resource.h> 37#include <sys/rman.h> 38 39#include <isa/isareg.h> 40#include <isa/isavar.h> 41 42#include <i386/isa/isa_device.h> 43 44#include <dev/iicbus/iiconf.h> 45#include "iicbus_if.h" 46 47#define IO_PCFSIZE 2 48 49#define TIMEOUT 9999 /* XXX */ 50 51/* Status bits of S1 register (read only) */ 52#define nBB 0x01 /* busy when low set/reset by STOP/START*/ 53#define LAB 0x02 /* lost arbitration bit in multi-master mode */ 54#define AAS 0x04 /* addressed as slave */ 55#define LRB 0x08 /* last received byte when not AAS */ 56#define AD0 0x08 /* general call received when AAS */ 57#define BER 0x10 /* bus error, misplaced START or STOP */ 58#define STS 0x20 /* STOP detected in slave receiver mode */ 59#define PIN 0x80 /* pending interrupt not (r/w) */ 60 61/* Control bits of S1 register (write only) */ 62#define ACK 0x01 63#define STO 0x02 64#define STA 0x04 65#define ENI 0x08 66#define ES2 0x10 67#define ES1 0x20 68#define ES0 0x40 69 70#define BUFSIZE 2048 71 72#define SLAVE_TRANSMITTER 0x1 73#define SLAVE_RECEIVER 0x2 74 75#define PCF_DEFAULT_ADDR 0xaa 76 77struct pcf_softc { 78 79 int pcf_base; /* isa port */ 80 int pcf_flags; 81 u_char pcf_addr; /* interface I2C address */ 82 83 int pcf_slave_mode; /* receiver or transmitter */ 84 int pcf_started; /* 1 if start condition sent */ 85 86 device_t iicbus; /* the corresponding iicbus */ 87 88 int rid_irq, rid_ioport; 89 struct resource *res_irq, *res_ioport; 90 void *intr_cookie; 91}; 92 93static int pcf_probe(device_t); 94static int pcf_attach(device_t); 95static void pcfintr(void *arg); 96 97static int pcf_print_child(device_t, device_t); 98 99static int pcf_repeated_start(device_t, u_char, int); 100static int pcf_start(device_t, u_char, int); 101static int pcf_stop(device_t); 102static int pcf_write(device_t, char *, int, int *, int); 103static int pcf_read(device_t, char *, int, int *, int, int); 104static int pcf_rst_card(device_t, u_char, u_char, u_char *); 105 106static device_method_t pcf_methods[] = { 107 /* device interface */ 108 DEVMETHOD(device_probe, pcf_probe), 109 DEVMETHOD(device_attach, pcf_attach), 110 111 /* bus interface */ 112 DEVMETHOD(bus_print_child, pcf_print_child), 113 114 /* iicbus interface */ 115 DEVMETHOD(iicbus_callback, iicbus_null_callback), 116 DEVMETHOD(iicbus_repeated_start, pcf_repeated_start), 117 DEVMETHOD(iicbus_start, pcf_start), 118 DEVMETHOD(iicbus_stop, pcf_stop), 119 DEVMETHOD(iicbus_write, pcf_write), 120 DEVMETHOD(iicbus_read, pcf_read), 121 DEVMETHOD(iicbus_reset, pcf_rst_card), 122 123 { 0, 0 } 124}; 125 126static driver_t pcf_driver = { 127 "pcf", 128 pcf_methods, 129 sizeof(struct pcf_softc), 130}; 131 132static devclass_t pcf_devclass; 133 134#define DEVTOSOFTC(dev) ((struct pcf_softc *)device_get_softc(dev)) 135 136static int 137pcf_probe(device_t pcfdev) 138{ 139 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 140 device_t parent = device_get_parent(pcfdev); 141 142 device_set_desc(pcfdev, "PCF8584 I2C bus controller"); 143 144 pcf = DEVTOSOFTC(pcfdev); 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); 175error: 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 185static int 186pcf_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, INTR_TYPE_NET, 195 pcfintr, pcfdev, &pcf->intr_cookie); 196 if (error) 197 return (error); 198 } 199 200 pcf->iicbus = iicbus_alloc_bus(pcfdev); 201 202 /* probe and attach the iicbus */ 203 device_probe_and_attach(pcf->iicbus); 204 205 return (0); 206} 207 208static int 209pcf_print_child(device_t bus, device_t dev) 210{ 211 struct pcf_softc *pcf = (struct pcf_softc *)device_get_softc(bus); 212 int retval = 0; 213 214 retval += bus_print_child_header(bus, dev); 215 retval += printf(" on %s addr 0x%x\n", device_get_nameunit(bus), 216 (int)pcf->pcf_addr); 217 218 return (retval); 219} 220 221/* 222 * PCF8584 datasheet : when operate at 8 MHz or more, a minimun time of 223 * 6 clocks cycles must be left between two consecutives access 224 */ 225#define pcf_nops() DELAY(10) 226 227#define dummy_read(pcf) PCF_GET_S0(pcf) 228#define dummy_write(pcf) PCF_SET_S0(pcf, 0) 229 230/* 231 * Specific register access to PCF8584 232 */ 233static void PCF_SET_S0(struct pcf_softc *pcf, int data) 234{ 235 outb(pcf->pcf_base, data); 236 pcf_nops(); 237} 238 239static void PCF_SET_S1(struct pcf_softc *pcf, int data) 240{ 241 outb(pcf->pcf_base+1, data); 242 pcf_nops(); 243} 244 245static char PCF_GET_S0(struct pcf_softc *pcf) 246{ 247 char data; 248 249 data = inb(pcf->pcf_base); 250 pcf_nops(); 251 252 return (data); 253} 254 255static char PCF_GET_S1(struct pcf_softc *pcf) 256{ 257 char data; 258 259 data = inb(pcf->pcf_base+1); 260 pcf_nops(); 261 262 return (data); 263} 264 265/* 266 * Polling mode for master operations wait for a new 267 * byte incomming or outgoing 268 */ 269static int pcf_wait_byte(struct pcf_softc *pcf) 270{ 271 int counter = TIMEOUT; 272 273 while (counter--) { 274 275 if ((PCF_GET_S1(pcf) & PIN) == 0) 276 return (0); 277 } 278 279 return (IIC_ETIMEOUT); 280} 281 282static int pcf_stop(device_t pcfdev) 283{ 284 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 285 286 /* 287 * Send STOP condition iff the START condition was previously sent. 288 * STOP is sent only once even if a iicbus_stop() is called after 289 * an iicbus_read()... see pcf_read(): the pcf needs to send the stop 290 * before the last char is read. 291 */ 292 if (pcf->pcf_started) { 293 /* set stop condition and enable IT */ 294 PCF_SET_S1(pcf, PIN|ES0|ENI|STO|ACK); 295 296 pcf->pcf_started = 0; 297 } 298 299 return (0); 300} 301 302 303static int pcf_noack(struct pcf_softc *pcf, int timeout) 304{ 305 int noack; 306 int k = timeout/10; 307 308 do { 309 noack = PCF_GET_S1(pcf) & LRB; 310 if (!noack) 311 break; 312 DELAY(10); /* XXX wait 10 us */ 313 } while (k--); 314 315 return (noack); 316} 317 318static int pcf_repeated_start(device_t pcfdev, u_char slave, int timeout) 319{ 320 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 321 int error = 0; 322 323 /* repeated start */ 324 PCF_SET_S1(pcf, ES0|STA|STO|ACK); 325 326 /* set slave address to PCF. Last bit (LSB) must be set correctly 327 * according to transfer direction */ 328 PCF_SET_S0(pcf, slave); 329 330 /* wait for address sent, polling */ 331 if ((error = pcf_wait_byte(pcf))) 332 goto error; 333 334 /* check for ack */ 335 if (pcf_noack(pcf, timeout)) { 336 error = IIC_ENOACK; 337 goto error; 338 } 339 340 return (0); 341 342error: 343 pcf_stop(pcfdev); 344 return (error); 345} 346 347static int pcf_start(device_t pcfdev, u_char slave, int timeout) 348{ 349 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 350 int error = 0; 351 352 if ((PCF_GET_S1(pcf) & nBB) == 0) 353 return (IIC_EBUSBSY); 354 355 /* set slave address to PCF. Last bit (LSB) must be set correctly 356 * according to transfer direction */ 357 PCF_SET_S0(pcf, slave); 358 359 /* START only */ 360 PCF_SET_S1(pcf, PIN|ES0|STA|ACK); 361 362 pcf->pcf_started = 1; 363 364 /* wait for address sent, polling */ 365 if ((error = pcf_wait_byte(pcf))) 366 goto error; 367 368 /* check for ACK */ 369 if (pcf_noack(pcf, timeout)) { 370 error = IIC_ENOACK; 371 goto error; 372 } 373 374 return (0); 375 376error: 377 pcf_stop(pcfdev); 378 return (error); 379} 380 381static void 382pcfintr(void *arg) 383{ 384 device_t pcfdev = (device_t)arg; 385 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 386 387 char data, status, addr; 388 char error = 0; 389 390 status = PCF_GET_S1(pcf); 391 392 if (status & PIN) { 393 device_printf(pcfdev, "spurious interrupt, status=0x%x\n", status & 0xff); 394 395 goto error; 396 } 397 398 if (status & LAB) 399 device_printf(pcfdev, "bus arbitration lost!\n"); 400 401 if (status & BER) { 402 error = IIC_EBUSERR; 403 iicbus_intr(pcf->iicbus, INTR_ERROR, &error); 404 405 goto error; 406 } 407 408 do { 409 status = PCF_GET_S1(pcf); 410 411 switch(pcf->pcf_slave_mode) { 412 413 case SLAVE_TRANSMITTER: 414 if (status & LRB) { 415 /* ack interrupt line */ 416 dummy_write(pcf); 417 418 /* no ack, don't send anymore */ 419 pcf->pcf_slave_mode = SLAVE_RECEIVER; 420 421 iicbus_intr(pcf->iicbus, INTR_NOACK, NULL); 422 break; 423 } 424 425 /* get data from upper code */ 426 iicbus_intr(pcf->iicbus, INTR_TRANSMIT, &data); 427 428 PCF_SET_S0(pcf, data); 429 break; 430 431 case SLAVE_RECEIVER: 432 if (status & AAS) { 433 addr = PCF_GET_S0(pcf); 434 435 if (status & AD0) 436 iicbus_intr(pcf->iicbus, INTR_GENERAL, &addr); 437 else 438 iicbus_intr(pcf->iicbus, INTR_START, &addr); 439 440 if (addr & LSB) { 441 pcf->pcf_slave_mode = SLAVE_TRANSMITTER; 442 443 /* get the first char from upper code */ 444 iicbus_intr(pcf->iicbus, INTR_TRANSMIT, &data); 445 446 /* send first data byte */ 447 PCF_SET_S0(pcf, data); 448 } 449 450 break; 451 } 452 453 /* stop condition received? */ 454 if (status & STS) { 455 /* ack interrupt line */ 456 dummy_read(pcf); 457 458 /* emulate intr stop condition */ 459 iicbus_intr(pcf->iicbus, INTR_STOP, NULL); 460 461 } else { 462 /* get data, ack interrupt line */ 463 data = PCF_GET_S0(pcf); 464 465 /* deliver the character */ 466 iicbus_intr(pcf->iicbus, INTR_RECEIVE, &data); 467 } 468 break; 469 470 default: 471 panic("%s: unknown slave mode (%d)!", __func__, 472 pcf->pcf_slave_mode); 473 } 474 475 } while ((PCF_GET_S1(pcf) & PIN) == 0); 476 477 return; 478 479error: 480 /* unknown event on bus...reset PCF */ 481 PCF_SET_S1(pcf, PIN|ES0|ENI|ACK); 482 483 pcf->pcf_slave_mode = SLAVE_RECEIVER; 484 485 return; 486} 487 488static int pcf_rst_card(device_t pcfdev, u_char speed, u_char addr, u_char *oldaddr) 489{ 490 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 491 492 if (oldaddr) 493 *oldaddr = pcf->pcf_addr; 494 495 /* retrieve own address from bus level */ 496 if (!addr) 497 pcf->pcf_addr = PCF_DEFAULT_ADDR; 498 else 499 pcf->pcf_addr = addr; 500 501 PCF_SET_S1(pcf, PIN); /* initialize S1 */ 502 503 /* own address S'O<>0 */ 504 PCF_SET_S0(pcf, pcf->pcf_addr >> 1); 505 506 /* select clock register */ 507 PCF_SET_S1(pcf, PIN|ES1); 508 509 /* select bus speed : 18=90kb, 19=45kb, 1A=11kb, 1B=1.5kb */ 510 switch (speed) { 511 case IIC_SLOW: 512 PCF_SET_S0(pcf, 0x1b); 513 break; 514 515 case IIC_FAST: 516 PCF_SET_S0(pcf, 0x19); 517 break; 518 519 case IIC_UNKNOWN: 520 case IIC_FASTEST: 521 default: 522 PCF_SET_S0(pcf, 0x18); 523 break; 524 } 525 526 /* set bus on, ack=yes, INT=yes */ 527 PCF_SET_S1(pcf, PIN|ES0|ENI|ACK); 528 529 pcf->pcf_slave_mode = SLAVE_RECEIVER; 530 531 return (0); 532} 533 534static int 535pcf_write(device_t pcfdev, char *buf, int len, int *sent, int timeout /* us */) 536{ 537 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 538 int bytes, error = 0; 539 540#ifdef PCFDEBUG 541 printf("pcf%d: >> writing %d bytes\n", device_get_unit(pcfdev), len); 542#endif 543 544 bytes = 0; 545 while (len) { 546 547 PCF_SET_S0(pcf, *buf++); 548 549 /* wait for the byte to be send */ 550 if ((error = pcf_wait_byte(pcf))) 551 goto error; 552 553 /* check if ack received */ 554 if (pcf_noack(pcf, timeout)) { 555 error = IIC_ENOACK; 556 goto error; 557 } 558 559 len --; 560 bytes ++; 561 } 562 563error: 564 *sent = bytes; 565 566#ifdef PCFDEBUG 567 printf("pcf%d: >> %d bytes written (%d)\n", 568 device_get_unit(pcfdev), bytes, error); 569#endif 570 571 return (error); 572} 573 574static int 575pcf_read(device_t pcfdev, char *buf, int len, int *read, int last, 576 int delay /* us */) 577{ 578 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 579 int bytes, error = 0; 580 581#ifdef PCFDEBUG 582 printf("pcf%d: << reading %d bytes\n", device_get_unit(pcfdev), len); 583#endif 584 585 /* trig the bus to get the first data byte in S0 */ 586 if (len) { 587 if (len == 1 && last) 588 /* just one byte to read */ 589 PCF_SET_S1(pcf, ES0); /* no ack */ 590 591 dummy_read(pcf); 592 } 593 594 bytes = 0; 595 while (len) { 596 597 /* XXX delay needed here */ 598 599 /* wait for trigged byte */ 600 if ((error = pcf_wait_byte(pcf))) { 601 pcf_stop(pcfdev); 602 goto error; 603 } 604 605 if (len == 1 && last) 606 /* ok, last data byte already in S0, no I2C activity 607 * on next PCF_GET_S0() */ 608 pcf_stop(pcfdev); 609 610 else if (len == 2 && last) 611 /* next trigged byte with no ack */ 612 PCF_SET_S1(pcf, ES0); 613 614 /* receive byte, trig next byte */ 615 *buf++ = PCF_GET_S0(pcf); 616 617 len --; 618 bytes ++; 619 }; 620 621error: 622 *read = bytes; 623 624#ifdef PCFDEBUG 625 printf("pcf%d: << %d bytes read (%d)\n", 626 device_get_unit(pcfdev), bytes, error); 627#endif 628 629 return (error); 630} 631 632DRIVER_MODULE(pcf, isa, pcf_driver, pcf_devclass, 0, 0); 633