1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1998 Nicolas Souchu, Marc Bouget 5 * Copyright (c) 2004 Joerg Wunsch 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/bus.h> 35 #include <sys/lock.h> 36 #include <sys/kernel.h> 37 #include <sys/module.h> 38 #include <sys/mutex.h> 39 #include <sys/systm.h> 40 41 #include <machine/bus.h> 42 #include <machine/resource.h> 43 44 #include <sys/rman.h> 45 46 #include <dev/iicbus/iicbus.h> 47 #include <dev/iicbus/iiconf.h> 48 #include <dev/pcf/pcfvar.h> 49 #include "iicbus_if.h" 50 51 /* Not so official debugging option. */ 52 /* #define PCFDEBUG */ 53 54 static int pcf_wait_byte(struct pcf_softc *pcf); 55 static int pcf_noack(struct pcf_softc *pcf, int timeout); 56 static void pcf_stop_locked(struct pcf_softc *pcf); 57 58 /* 59 * Polling mode for master operations wait for a new 60 * byte incoming or outgoing 61 */ 62 static int 63 pcf_wait_byte(struct pcf_softc *sc) 64 { 65 int counter = TIMEOUT; 66 67 PCF_ASSERT_LOCKED(sc); 68 while (counter--) { 69 if ((pcf_get_S1(sc) & PIN) == 0) 70 return (0); 71 } 72 73 #ifdef PCFDEBUG 74 printf("pcf: timeout!\n"); 75 #endif 76 77 return (IIC_ETIMEOUT); 78 } 79 80 static void 81 pcf_stop_locked(struct pcf_softc *sc) 82 { 83 84 PCF_ASSERT_LOCKED(sc); 85 #ifdef PCFDEBUG 86 device_printf(dev, " >> stop\n"); 87 #endif 88 /* 89 * Send STOP condition iff the START condition was previously sent. 90 * STOP is sent only once even if an iicbus_stop() is called after 91 * an iicbus_read()... see pcf_read(): the PCF needs to send the stop 92 * before the last char is read. 93 */ 94 if (sc->pcf_started) { 95 /* set stop condition and enable IT */ 96 pcf_set_S1(sc, PIN|ESO|ENI|STO|ACK); 97 98 sc->pcf_started = 0; 99 } 100 } 101 102 static int 103 pcf_noack(struct pcf_softc *sc, int timeout) 104 { 105 int noack; 106 int k = timeout/10; 107 108 PCF_ASSERT_LOCKED(sc); 109 do { 110 noack = pcf_get_S1(sc) & LRB; 111 if (!noack) 112 break; 113 DELAY(10); /* XXX wait 10 us */ 114 } while (k--); 115 116 return (noack); 117 } 118 119 int 120 pcf_repeated_start(device_t dev, u_char slave, int timeout) 121 { 122 struct pcf_softc *sc = DEVTOSOFTC(dev); 123 int error = 0; 124 125 PCF_LOCK(sc); 126 #ifdef PCFDEBUG 127 device_printf(dev, " >> repeated start for slave %#x\n", 128 (unsigned)slave); 129 #endif 130 /* repeated start */ 131 pcf_set_S1(sc, ESO|STA|STO|ACK); 132 133 /* set slave address to PCF. Last bit (LSB) must be set correctly 134 * according to transfer direction */ 135 pcf_set_S0(sc, slave); 136 137 /* wait for address sent, polling */ 138 if ((error = pcf_wait_byte(sc))) 139 goto error; 140 141 /* check for ack */ 142 if (pcf_noack(sc, timeout)) { 143 error = IIC_ENOACK; 144 #ifdef PCFDEBUG 145 printf("pcf: no ack on repeated_start!\n"); 146 #endif 147 goto error; 148 } 149 150 PCF_UNLOCK(sc); 151 return (0); 152 153 error: 154 pcf_stop_locked(sc); 155 PCF_UNLOCK(sc); 156 return (error); 157 } 158 159 int 160 pcf_start(device_t dev, u_char slave, int timeout) 161 { 162 struct pcf_softc *sc = DEVTOSOFTC(dev); 163 int error = 0; 164 165 PCF_LOCK(sc); 166 #ifdef PCFDEBUG 167 device_printf(dev, " >> start for slave %#x\n", (unsigned)slave); 168 #endif 169 if ((pcf_get_S1(sc) & nBB) == 0) { 170 #ifdef PCFDEBUG 171 printf("pcf: busy!\n"); 172 #endif 173 PCF_UNLOCK(sc); 174 return (IIC_EBUSERR); 175 } 176 177 /* set slave address to PCF. Last bit (LSB) must be set correctly 178 * according to transfer direction */ 179 pcf_set_S0(sc, slave); 180 181 /* START only */ 182 pcf_set_S1(sc, PIN|ESO|STA|ACK); 183 184 sc->pcf_started = 1; 185 186 /* wait for address sent, polling */ 187 if ((error = pcf_wait_byte(sc))) 188 goto error; 189 190 /* check for ACK */ 191 if (pcf_noack(sc, timeout)) { 192 error = IIC_ENOACK; 193 #ifdef PCFDEBUG 194 printf("pcf: no ack on start!\n"); 195 #endif 196 goto error; 197 } 198 199 PCF_UNLOCK(sc); 200 return (0); 201 202 error: 203 pcf_stop_locked(sc); 204 PCF_UNLOCK(sc); 205 return (error); 206 } 207 208 int 209 pcf_stop(device_t dev) 210 { 211 struct pcf_softc *sc = DEVTOSOFTC(dev); 212 213 #ifdef PCFDEBUG 214 device_printf(dev, " >> stop\n"); 215 #endif 216 PCF_LOCK(sc); 217 pcf_stop_locked(sc); 218 PCF_UNLOCK(sc); 219 220 return (0); 221 } 222 223 void 224 pcf_intr(void *arg) 225 { 226 struct pcf_softc *sc = arg; 227 char data, status, addr; 228 char error = 0; 229 230 PCF_LOCK(sc); 231 status = pcf_get_S1(sc); 232 233 if (status & PIN) { 234 printf("pcf: spurious interrupt, status=0x%x\n", 235 status & 0xff); 236 237 goto error; 238 } 239 240 if (status & LAB) 241 printf("pcf: bus arbitration lost!\n"); 242 243 if (status & BER) { 244 error = IIC_EBUSERR; 245 iicbus_intr(sc->iicbus, INTR_ERROR, &error); 246 247 goto error; 248 } 249 250 do { 251 status = pcf_get_S1(sc); 252 253 switch(sc->pcf_slave_mode) { 254 case SLAVE_TRANSMITTER: 255 if (status & LRB) { 256 /* ack interrupt line */ 257 dummy_write(sc); 258 259 /* no ack, don't send anymore */ 260 sc->pcf_slave_mode = SLAVE_RECEIVER; 261 262 iicbus_intr(sc->iicbus, INTR_NOACK, NULL); 263 break; 264 } 265 266 /* get data from upper code */ 267 iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data); 268 269 pcf_set_S0(sc, data); 270 break; 271 272 case SLAVE_RECEIVER: 273 if (status & AAS) { 274 addr = pcf_get_S0(sc); 275 276 if (status & AD0) 277 iicbus_intr(sc->iicbus, INTR_GENERAL, &addr); 278 else 279 iicbus_intr(sc->iicbus, INTR_START, &addr); 280 281 if (addr & LSB) { 282 sc->pcf_slave_mode = SLAVE_TRANSMITTER; 283 284 /* get the first char from upper code */ 285 iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data); 286 287 /* send first data byte */ 288 pcf_set_S0(sc, data); 289 } 290 291 break; 292 } 293 294 /* stop condition received? */ 295 if (status & STS) { 296 /* ack interrupt line */ 297 dummy_read(sc); 298 299 /* emulate intr stop condition */ 300 iicbus_intr(sc->iicbus, INTR_STOP, NULL); 301 302 } else { 303 /* get data, ack interrupt line */ 304 data = pcf_get_S0(sc); 305 306 /* deliver the character */ 307 iicbus_intr(sc->iicbus, INTR_RECEIVE, &data); 308 } 309 break; 310 311 default: 312 panic("%s: unknown slave mode (%d)!", __func__, 313 sc->pcf_slave_mode); 314 } 315 316 } while ((pcf_get_S1(sc) & PIN) == 0); 317 PCF_UNLOCK(sc); 318 319 return; 320 321 error: 322 /* unknown event on bus...reset PCF */ 323 pcf_set_S1(sc, PIN|ESO|ENI|ACK); 324 325 sc->pcf_slave_mode = SLAVE_RECEIVER; 326 PCF_UNLOCK(sc); 327 328 return; 329 } 330 331 int 332 pcf_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 333 { 334 struct pcf_softc *sc = DEVTOSOFTC(dev); 335 336 PCF_LOCK(sc); 337 if (oldaddr) 338 *oldaddr = sc->pcf_addr; 339 340 /* retrieve own address from bus level */ 341 if (!addr) 342 sc->pcf_addr = PCF_DEFAULT_ADDR; 343 else 344 sc->pcf_addr = addr; 345 346 pcf_set_S1(sc, PIN); /* initialize S1 */ 347 348 /* own address S'O<>0 */ 349 pcf_set_S0(sc, sc->pcf_addr >> 1); 350 351 /* select clock register */ 352 pcf_set_S1(sc, PIN|ES1); 353 354 /* select bus speed : 18=90kb, 19=45kb, 1A=11kb, 1B=1.5kb */ 355 switch (speed) { 356 case IIC_SLOW: 357 pcf_set_S0(sc, 0x1b); /* XXX Sun uses 0x1f */ 358 break; 359 360 case IIC_FAST: 361 pcf_set_S0(sc, 0x19); /* XXX Sun: 0x1d */ 362 break; 363 364 case IIC_UNKNOWN: 365 case IIC_FASTEST: 366 default: 367 pcf_set_S0(sc, 0x18); /* XXX Sun: 0x1c */ 368 break; 369 } 370 371 /* set bus on, ack=yes, INT=yes */ 372 pcf_set_S1(sc, PIN|ESO|ENI|ACK); 373 374 sc->pcf_slave_mode = SLAVE_RECEIVER; 375 PCF_UNLOCK(sc); 376 377 return (0); 378 } 379 380 int 381 pcf_write(device_t dev, const char *buf, int len, int *sent, int timeout /* us */) 382 { 383 struct pcf_softc *sc = DEVTOSOFTC(dev); 384 int bytes, error = 0; 385 386 #ifdef PCFDEBUG 387 device_printf(dev, " >> writing %d bytes: %#x%s\n", len, 388 (unsigned)buf[0], len > 1? "...": ""); 389 #endif 390 391 bytes = 0; 392 PCF_LOCK(sc); 393 while (len) { 394 pcf_set_S0(sc, *buf++); 395 396 /* wait for the byte to be send */ 397 if ((error = pcf_wait_byte(sc))) 398 goto error; 399 400 /* check if ack received */ 401 if (pcf_noack(sc, timeout)) { 402 error = IIC_ENOACK; 403 goto error; 404 } 405 406 len --; 407 bytes ++; 408 } 409 410 error: 411 *sent = bytes; 412 PCF_UNLOCK(sc); 413 414 #ifdef PCFDEBUG 415 device_printf(dev, " >> %d bytes written (%d)\n", bytes, error); 416 #endif 417 418 return (error); 419 } 420 421 int 422 pcf_read(device_t dev, char *buf, int len, int *read, int last, 423 int delay /* us */) 424 { 425 struct pcf_softc *sc = DEVTOSOFTC(dev); 426 int bytes, error = 0; 427 #ifdef PCFDEBUG 428 char *obuf = buf; 429 430 device_printf(dev, " << reading %d bytes\n", len); 431 #endif 432 433 PCF_LOCK(sc); 434 /* trig the bus to get the first data byte in S0 */ 435 if (len) { 436 if (len == 1 && last) 437 /* just one byte to read */ 438 pcf_set_S1(sc, ESO); /* no ack */ 439 440 dummy_read(sc); 441 } 442 443 bytes = 0; 444 while (len) { 445 /* XXX delay needed here */ 446 447 /* wait for trigged byte */ 448 if ((error = pcf_wait_byte(sc))) { 449 pcf_stop_locked(sc); 450 goto error; 451 } 452 453 if (len == 1 && last) 454 /* ok, last data byte already in S0, no I2C activity 455 * on next pcf_get_S0() */ 456 pcf_stop_locked(sc); 457 458 else if (len == 2 && last) 459 /* next trigged byte with no ack */ 460 pcf_set_S1(sc, ESO); 461 462 /* receive byte, trig next byte */ 463 *buf++ = pcf_get_S0(sc); 464 465 len --; 466 bytes ++; 467 } 468 469 error: 470 *read = bytes; 471 PCF_UNLOCK(sc); 472 473 #ifdef PCFDEBUG 474 device_printf(dev, " << %d bytes read (%d): %#x%s\n", bytes, error, 475 (unsigned)obuf[0], bytes > 1? "...": ""); 476 #endif 477 478 return (error); 479 } 480 481 DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0); 482 MODULE_DEPEND(pcf, iicbus, PCF_MINVER, PCF_PREFVER, PCF_MAXVER); 483 MODULE_VERSION(pcf, PCF_MODVER); 484