Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/i386/isa/pcf.c
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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 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD: releng/5.2/sys/i386/isa/pcf.c 116599 2003-06-20 07:22:54Z jmg $"); 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 36 #include <machine/bus.h> 37 #include <machine/resource.h> 38 #include <sys/rman.h> 39 40 #include <isa/isareg.h> 41 #include <isa/isavar.h> 42 43 #include <i386/isa/isa_device.h> 44 45 #include <dev/iicbus/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, 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 uintptr_t base; 143 144 device_set_desc(pcfdev, "PCF8584 I2C bus controller"); 145 146 pcf = DEVTOSOFTC(pcfdev); 147 bzero(pcf, sizeof(struct pcf_softc)); 148 149 pcf->rid_irq = pcf->rid_ioport = 0; 150 pcf->res_irq = pcf->res_ioport = 0; 151 152 /* IO port is mandatory */ 153 pcf->res_ioport = bus_alloc_resource(pcfdev, SYS_RES_IOPORT, 154 &pcf->rid_ioport, 0ul, ~0ul, 155 IO_PCFSIZE, RF_ACTIVE); 156 if (pcf->res_ioport == 0) { 157 device_printf(pcfdev, "cannot reserve I/O port range\n"); 158 goto error; 159 } 160 BUS_READ_IVAR(parent, pcfdev, ISA_IVAR_PORT, &base); 161 pcf->pcf_base = base; 162 163 pcf->pcf_flags = device_get_flags(pcfdev); 164 165 if (!(pcf->pcf_flags & IIC_POLLED)) { 166 pcf->res_irq = bus_alloc_resource(pcfdev, SYS_RES_IRQ, &pcf->rid_irq, 167 0ul, ~0ul, 1, RF_ACTIVE); 168 if (pcf->res_irq == 0) { 169 device_printf(pcfdev, "can't reserve irq, polled mode.\n"); 170 pcf->pcf_flags |= IIC_POLLED; 171 } 172 } 173 174 /* reset the chip */ 175 pcf_rst_card(pcfdev, IIC_FASTEST, PCF_DEFAULT_ADDR, NULL); 176 177 return (0); 178 error: 179 if (pcf->res_ioport != 0) { 180 bus_deactivate_resource(pcfdev, SYS_RES_IOPORT, pcf->rid_ioport, 181 pcf->res_ioport); 182 bus_release_resource(pcfdev, SYS_RES_IOPORT, pcf->rid_ioport, 183 pcf->res_ioport); 184 } 185 return (ENXIO); 186 } 187 188 static int 189 pcf_attach(device_t pcfdev) 190 { 191 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 192 device_t parent = device_get_parent(pcfdev); 193 int error = 0; 194 195 if (pcf->res_irq) { 196 /* default to the tty mask for registration */ /* XXX */ 197 error = BUS_SETUP_INTR(parent, pcfdev, pcf->res_irq, INTR_TYPE_NET, 198 pcfintr, pcfdev, &pcf->intr_cookie); 199 if (error) 200 return (error); 201 } 202 203 pcf->iicbus = device_add_child(pcfdev, "iicbus", -1); 204 205 /* probe and attach the iicbus */ 206 bus_generic_attach(pcfdev); 207 208 return (0); 209 } 210 211 static int 212 pcf_print_child(device_t bus, device_t dev) 213 { 214 struct pcf_softc *pcf = (struct pcf_softc *)device_get_softc(bus); 215 int retval = 0; 216 217 retval += bus_print_child_header(bus, dev); 218 retval += printf(" on %s addr 0x%x\n", device_get_nameunit(bus), 219 (int)pcf->pcf_addr); 220 221 return (retval); 222 } 223 224 /* 225 * PCF8584 datasheet : when operate at 8 MHz or more, a minimun time of 226 * 6 clocks cycles must be left between two consecutives access 227 */ 228 #define pcf_nops() DELAY(10) 229 230 #define dummy_read(pcf) PCF_GET_S0(pcf) 231 #define dummy_write(pcf) PCF_SET_S0(pcf, 0) 232 233 /* 234 * Specific register access to PCF8584 235 */ 236 static void PCF_SET_S0(struct pcf_softc *pcf, int data) 237 { 238 outb(pcf->pcf_base, data); 239 pcf_nops(); 240 } 241 242 static void 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 PCF_GET_S0(struct pcf_softc *pcf) 249 { 250 char data; 251 252 data = inb(pcf->pcf_base); 253 pcf_nops(); 254 255 return (data); 256 } 257 258 static char PCF_GET_S1(struct pcf_softc *pcf) 259 { 260 char data; 261 262 data = inb(pcf->pcf_base+1); 263 pcf_nops(); 264 265 return (data); 266 } 267 268 /* 269 * Polling mode for master operations wait for a new 270 * byte incomming or outgoing 271 */ 272 static int pcf_wait_byte(struct pcf_softc *pcf) 273 { 274 int counter = TIMEOUT; 275 276 while (counter--) { 277 278 if ((PCF_GET_S1(pcf) & PIN) == 0) 279 return (0); 280 } 281 282 return (IIC_ETIMEOUT); 283 } 284 285 static int pcf_stop(device_t pcfdev) 286 { 287 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 288 289 /* 290 * Send STOP condition iff the START condition was previously sent. 291 * STOP is sent only once even if an iicbus_stop() is called after 292 * an iicbus_read()... see pcf_read(): the pcf needs to send the stop 293 * before the last char is read. 294 */ 295 if (pcf->pcf_started) { 296 /* set stop condition and enable IT */ 297 PCF_SET_S1(pcf, PIN|ES0|ENI|STO|ACK); 298 299 pcf->pcf_started = 0; 300 } 301 302 return (0); 303 } 304 305 306 static int pcf_noack(struct pcf_softc *pcf, int timeout) 307 { 308 int noack; 309 int k = timeout/10; 310 311 do { 312 noack = PCF_GET_S1(pcf) & LRB; 313 if (!noack) 314 break; 315 DELAY(10); /* XXX wait 10 us */ 316 } while (k--); 317 318 return (noack); 319 } 320 321 static int pcf_repeated_start(device_t pcfdev, u_char slave, int timeout) 322 { 323 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 324 int error = 0; 325 326 /* repeated start */ 327 PCF_SET_S1(pcf, ES0|STA|STO|ACK); 328 329 /* set slave address to PCF. Last bit (LSB) must be set correctly 330 * according to transfer direction */ 331 PCF_SET_S0(pcf, slave); 332 333 /* wait for address sent, polling */ 334 if ((error = pcf_wait_byte(pcf))) 335 goto error; 336 337 /* check for ack */ 338 if (pcf_noack(pcf, timeout)) { 339 error = IIC_ENOACK; 340 goto error; 341 } 342 343 return (0); 344 345 error: 346 pcf_stop(pcfdev); 347 return (error); 348 } 349 350 static int pcf_start(device_t pcfdev, u_char slave, int timeout) 351 { 352 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 353 int error = 0; 354 355 if ((PCF_GET_S1(pcf) & nBB) == 0) 356 return (IIC_EBUSBSY); 357 358 /* set slave address to PCF. Last bit (LSB) must be set correctly 359 * according to transfer direction */ 360 PCF_SET_S0(pcf, slave); 361 362 /* START only */ 363 PCF_SET_S1(pcf, PIN|ES0|STA|ACK); 364 365 pcf->pcf_started = 1; 366 367 /* wait for address sent, polling */ 368 if ((error = pcf_wait_byte(pcf))) 369 goto error; 370 371 /* check for ACK */ 372 if (pcf_noack(pcf, timeout)) { 373 error = IIC_ENOACK; 374 goto error; 375 } 376 377 return (0); 378 379 error: 380 pcf_stop(pcfdev); 381 return (error); 382 } 383 384 static void 385 pcfintr(void *arg) 386 { 387 device_t pcfdev = (device_t)arg; 388 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 389 390 char data, status, addr; 391 char error = 0; 392 393 status = PCF_GET_S1(pcf); 394 395 if (status & PIN) { 396 device_printf(pcfdev, "spurious interrupt, status=0x%x\n", status & 0xff); 397 398 goto error; 399 } 400 401 if (status & LAB) 402 device_printf(pcfdev, "bus arbitration lost!\n"); 403 404 if (status & BER) { 405 error = IIC_EBUSERR; 406 iicbus_intr(pcf->iicbus, INTR_ERROR, &error); 407 408 goto error; 409 } 410 411 do { 412 status = PCF_GET_S1(pcf); 413 414 switch(pcf->pcf_slave_mode) { 415 416 case SLAVE_TRANSMITTER: 417 if (status & LRB) { 418 /* ack interrupt line */ 419 dummy_write(pcf); 420 421 /* no ack, don't send anymore */ 422 pcf->pcf_slave_mode = SLAVE_RECEIVER; 423 424 iicbus_intr(pcf->iicbus, INTR_NOACK, NULL); 425 break; 426 } 427 428 /* get data from upper code */ 429 iicbus_intr(pcf->iicbus, INTR_TRANSMIT, &data); 430 431 PCF_SET_S0(pcf, data); 432 break; 433 434 case SLAVE_RECEIVER: 435 if (status & AAS) { 436 addr = PCF_GET_S0(pcf); 437 438 if (status & AD0) 439 iicbus_intr(pcf->iicbus, INTR_GENERAL, &addr); 440 else 441 iicbus_intr(pcf->iicbus, INTR_START, &addr); 442 443 if (addr & LSB) { 444 pcf->pcf_slave_mode = SLAVE_TRANSMITTER; 445 446 /* get the first char from upper code */ 447 iicbus_intr(pcf->iicbus, INTR_TRANSMIT, &data); 448 449 /* send first data byte */ 450 PCF_SET_S0(pcf, data); 451 } 452 453 break; 454 } 455 456 /* stop condition received? */ 457 if (status & STS) { 458 /* ack interrupt line */ 459 dummy_read(pcf); 460 461 /* emulate intr stop condition */ 462 iicbus_intr(pcf->iicbus, INTR_STOP, NULL); 463 464 } else { 465 /* get data, ack interrupt line */ 466 data = PCF_GET_S0(pcf); 467 468 /* deliver the character */ 469 iicbus_intr(pcf->iicbus, INTR_RECEIVE, &data); 470 } 471 break; 472 473 default: 474 panic("%s: unknown slave mode (%d)!", __func__, 475 pcf->pcf_slave_mode); 476 } 477 478 } while ((PCF_GET_S1(pcf) & PIN) == 0); 479 480 return; 481 482 error: 483 /* unknown event on bus...reset PCF */ 484 PCF_SET_S1(pcf, PIN|ES0|ENI|ACK); 485 486 pcf->pcf_slave_mode = SLAVE_RECEIVER; 487 488 return; 489 } 490 491 static int pcf_rst_card(device_t pcfdev, u_char speed, u_char addr, u_char *oldaddr) 492 { 493 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 494 495 if (oldaddr) 496 *oldaddr = pcf->pcf_addr; 497 498 /* retrieve own address from bus level */ 499 if (!addr) 500 pcf->pcf_addr = PCF_DEFAULT_ADDR; 501 else 502 pcf->pcf_addr = addr; 503 504 PCF_SET_S1(pcf, PIN); /* initialize S1 */ 505 506 /* own address S'O<>0 */ 507 PCF_SET_S0(pcf, pcf->pcf_addr >> 1); 508 509 /* select clock register */ 510 PCF_SET_S1(pcf, PIN|ES1); 511 512 /* select bus speed : 18=90kb, 19=45kb, 1A=11kb, 1B=1.5kb */ 513 switch (speed) { 514 case IIC_SLOW: 515 PCF_SET_S0(pcf, 0x1b); 516 break; 517 518 case IIC_FAST: 519 PCF_SET_S0(pcf, 0x19); 520 break; 521 522 case IIC_UNKNOWN: 523 case IIC_FASTEST: 524 default: 525 PCF_SET_S0(pcf, 0x18); 526 break; 527 } 528 529 /* set bus on, ack=yes, INT=yes */ 530 PCF_SET_S1(pcf, PIN|ES0|ENI|ACK); 531 532 pcf->pcf_slave_mode = SLAVE_RECEIVER; 533 534 return (0); 535 } 536 537 static int 538 pcf_write(device_t pcfdev, char *buf, int len, int *sent, int timeout /* us */) 539 { 540 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 541 int bytes, error = 0; 542 543 #ifdef PCFDEBUG 544 printf("pcf%d: >> writing %d bytes\n", device_get_unit(pcfdev), len); 545 #endif 546 547 bytes = 0; 548 while (len) { 549 550 PCF_SET_S0(pcf, *buf++); 551 552 /* wait for the byte to be send */ 553 if ((error = pcf_wait_byte(pcf))) 554 goto error; 555 556 /* check if ack received */ 557 if (pcf_noack(pcf, timeout)) { 558 error = IIC_ENOACK; 559 goto error; 560 } 561 562 len --; 563 bytes ++; 564 } 565 566 error: 567 *sent = bytes; 568 569 #ifdef PCFDEBUG 570 printf("pcf%d: >> %d bytes written (%d)\n", 571 device_get_unit(pcfdev), bytes, error); 572 #endif 573 574 return (error); 575 } 576 577 static int 578 pcf_read(device_t pcfdev, char *buf, int len, int *read, int last, 579 int delay /* us */) 580 { 581 struct pcf_softc *pcf = DEVTOSOFTC(pcfdev); 582 int bytes, error = 0; 583 584 #ifdef PCFDEBUG 585 printf("pcf%d: << reading %d bytes\n", device_get_unit(pcfdev), len); 586 #endif 587 588 /* trig the bus to get the first data byte in S0 */ 589 if (len) { 590 if (len == 1 && last) 591 /* just one byte to read */ 592 PCF_SET_S1(pcf, ES0); /* no ack */ 593 594 dummy_read(pcf); 595 } 596 597 bytes = 0; 598 while (len) { 599 600 /* XXX delay needed here */ 601 602 /* wait for trigged byte */ 603 if ((error = pcf_wait_byte(pcf))) { 604 pcf_stop(pcfdev); 605 goto error; 606 } 607 608 if (len == 1 && last) 609 /* ok, last data byte already in S0, no I2C activity 610 * on next PCF_GET_S0() */ 611 pcf_stop(pcfdev); 612 613 else if (len == 2 && last) 614 /* next trigged byte with no ack */ 615 PCF_SET_S1(pcf, ES0); 616 617 /* receive byte, trig next byte */ 618 *buf++ = PCF_GET_S0(pcf); 619 620 len --; 621 bytes ++; 622 }; 623 624 error: 625 *read = bytes; 626 627 #ifdef PCFDEBUG 628 printf("pcf%d: << %d bytes read (%d)\n", 629 device_get_unit(pcfdev), bytes, error); 630 #endif 631 632 return (error); 633 } 634 635 DRIVER_MODULE(pcf, isa, pcf_driver, pcf_devclass, 0, 0);
Cache object: 58252768d4f9950de0f91b7130d63b70
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