1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <sys/param.h> 32 #include <sys/bus.h> 33 #include <sys/lock.h> 34 #include <sys/kernel.h> 35 #include <sys/module.h> 36 #include <sys/mutex.h> 37 #include <sys/systm.h> 38 39 #include <machine/bus.h> 40 #include <machine/resource.h> 41 42 #include <sys/rman.h> 43 44 #include <dev/iicbus/iicbus.h> 45 #include <dev/iicbus/iiconf.h> 46 #include <dev/pcf/pcfvar.h> 47 #include "iicbus_if.h" 48 49 /* Not so official debugging option. */ 50 /* #define PCFDEBUG */ 51 52 static int pcf_wait_byte(struct pcf_softc *pcf); 53 static int pcf_noack(struct pcf_softc *pcf, int timeout); 54 static void pcf_stop_locked(struct pcf_softc *pcf); 55 56 /* 57 * Polling mode for master operations wait for a new 58 * byte incoming or outgoing 59 */ 60 static int 61 pcf_wait_byte(struct pcf_softc *sc) 62 { 63 int counter = TIMEOUT; 64 65 PCF_ASSERT_LOCKED(sc); 66 while (counter--) { 67 if ((pcf_get_S1(sc) & PIN) == 0) 68 return (0); 69 } 70 71 #ifdef PCFDEBUG 72 printf("pcf: timeout!\n"); 73 #endif 74 75 return (IIC_ETIMEOUT); 76 } 77 78 static void 79 pcf_stop_locked(struct pcf_softc *sc) 80 { 81 82 PCF_ASSERT_LOCKED(sc); 83 #ifdef PCFDEBUG 84 device_printf(dev, " >> stop\n"); 85 #endif 86 /* 87 * Send STOP condition iff the START condition was previously sent. 88 * STOP is sent only once even if an iicbus_stop() is called after 89 * an iicbus_read()... see pcf_read(): the PCF needs to send the stop 90 * before the last char is read. 91 */ 92 if (sc->pcf_started) { 93 /* set stop condition and enable IT */ 94 pcf_set_S1(sc, PIN|ESO|ENI|STO|ACK); 95 96 sc->pcf_started = 0; 97 } 98 } 99 100 static int 101 pcf_noack(struct pcf_softc *sc, int timeout) 102 { 103 int noack; 104 int k = timeout/10; 105 106 PCF_ASSERT_LOCKED(sc); 107 do { 108 noack = pcf_get_S1(sc) & LRB; 109 if (!noack) 110 break; 111 DELAY(10); /* XXX wait 10 us */ 112 } while (k--); 113 114 return (noack); 115 } 116 117 int 118 pcf_repeated_start(device_t dev, u_char slave, int timeout) 119 { 120 struct pcf_softc *sc = DEVTOSOFTC(dev); 121 int error = 0; 122 123 PCF_LOCK(sc); 124 #ifdef PCFDEBUG 125 device_printf(dev, " >> repeated start for slave %#x\n", 126 (unsigned)slave); 127 #endif 128 /* repeated start */ 129 pcf_set_S1(sc, ESO|STA|STO|ACK); 130 131 /* set slave address to PCF. Last bit (LSB) must be set correctly 132 * according to transfer direction */ 133 pcf_set_S0(sc, slave); 134 135 /* wait for address sent, polling */ 136 if ((error = pcf_wait_byte(sc))) 137 goto error; 138 139 /* check for ack */ 140 if (pcf_noack(sc, timeout)) { 141 error = IIC_ENOACK; 142 #ifdef PCFDEBUG 143 printf("pcf: no ack on repeated_start!\n"); 144 #endif 145 goto error; 146 } 147 148 PCF_UNLOCK(sc); 149 return (0); 150 151 error: 152 pcf_stop_locked(sc); 153 PCF_UNLOCK(sc); 154 return (error); 155 } 156 157 int 158 pcf_start(device_t dev, u_char slave, int timeout) 159 { 160 struct pcf_softc *sc = DEVTOSOFTC(dev); 161 int error = 0; 162 163 PCF_LOCK(sc); 164 #ifdef PCFDEBUG 165 device_printf(dev, " >> start for slave %#x\n", (unsigned)slave); 166 #endif 167 if ((pcf_get_S1(sc) & nBB) == 0) { 168 #ifdef PCFDEBUG 169 printf("pcf: busy!\n"); 170 #endif 171 PCF_UNLOCK(sc); 172 return (IIC_EBUSERR); 173 } 174 175 /* set slave address to PCF. Last bit (LSB) must be set correctly 176 * according to transfer direction */ 177 pcf_set_S0(sc, slave); 178 179 /* START only */ 180 pcf_set_S1(sc, PIN|ESO|STA|ACK); 181 182 sc->pcf_started = 1; 183 184 /* wait for address sent, polling */ 185 if ((error = pcf_wait_byte(sc))) 186 goto error; 187 188 /* check for ACK */ 189 if (pcf_noack(sc, timeout)) { 190 error = IIC_ENOACK; 191 #ifdef PCFDEBUG 192 printf("pcf: no ack on start!\n"); 193 #endif 194 goto error; 195 } 196 197 PCF_UNLOCK(sc); 198 return (0); 199 200 error: 201 pcf_stop_locked(sc); 202 PCF_UNLOCK(sc); 203 return (error); 204 } 205 206 int 207 pcf_stop(device_t dev) 208 { 209 struct pcf_softc *sc = DEVTOSOFTC(dev); 210 211 #ifdef PCFDEBUG 212 device_printf(dev, " >> stop\n"); 213 #endif 214 PCF_LOCK(sc); 215 pcf_stop_locked(sc); 216 PCF_UNLOCK(sc); 217 218 return (0); 219 } 220 221 void 222 pcf_intr(void *arg) 223 { 224 struct pcf_softc *sc = arg; 225 char data, status, addr; 226 char error = 0; 227 228 PCF_LOCK(sc); 229 status = pcf_get_S1(sc); 230 231 if (status & PIN) { 232 printf("pcf: spurious interrupt, status=0x%x\n", 233 status & 0xff); 234 235 goto error; 236 } 237 238 if (status & LAB) 239 printf("pcf: bus arbitration lost!\n"); 240 241 if (status & BER) { 242 error = IIC_EBUSERR; 243 iicbus_intr(sc->iicbus, INTR_ERROR, &error); 244 245 goto error; 246 } 247 248 do { 249 status = pcf_get_S1(sc); 250 251 switch(sc->pcf_slave_mode) { 252 case SLAVE_TRANSMITTER: 253 if (status & LRB) { 254 /* ack interrupt line */ 255 dummy_write(sc); 256 257 /* no ack, don't send anymore */ 258 sc->pcf_slave_mode = SLAVE_RECEIVER; 259 260 iicbus_intr(sc->iicbus, INTR_NOACK, NULL); 261 break; 262 } 263 264 /* get data from upper code */ 265 iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data); 266 267 pcf_set_S0(sc, data); 268 break; 269 270 case SLAVE_RECEIVER: 271 if (status & AAS) { 272 addr = pcf_get_S0(sc); 273 274 if (status & AD0) 275 iicbus_intr(sc->iicbus, INTR_GENERAL, &addr); 276 else 277 iicbus_intr(sc->iicbus, INTR_START, &addr); 278 279 if (addr & LSB) { 280 sc->pcf_slave_mode = SLAVE_TRANSMITTER; 281 282 /* get the first char from upper code */ 283 iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data); 284 285 /* send first data byte */ 286 pcf_set_S0(sc, data); 287 } 288 289 break; 290 } 291 292 /* stop condition received? */ 293 if (status & STS) { 294 /* ack interrupt line */ 295 dummy_read(sc); 296 297 /* emulate intr stop condition */ 298 iicbus_intr(sc->iicbus, INTR_STOP, NULL); 299 300 } else { 301 /* get data, ack interrupt line */ 302 data = pcf_get_S0(sc); 303 304 /* deliver the character */ 305 iicbus_intr(sc->iicbus, INTR_RECEIVE, &data); 306 } 307 break; 308 309 default: 310 panic("%s: unknown slave mode (%d)!", __func__, 311 sc->pcf_slave_mode); 312 } 313 314 } while ((pcf_get_S1(sc) & PIN) == 0); 315 PCF_UNLOCK(sc); 316 317 return; 318 319 error: 320 /* unknown event on bus...reset PCF */ 321 pcf_set_S1(sc, PIN|ESO|ENI|ACK); 322 323 sc->pcf_slave_mode = SLAVE_RECEIVER; 324 PCF_UNLOCK(sc); 325 326 return; 327 } 328 329 int 330 pcf_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr) 331 { 332 struct pcf_softc *sc = DEVTOSOFTC(dev); 333 334 PCF_LOCK(sc); 335 if (oldaddr) 336 *oldaddr = sc->pcf_addr; 337 338 /* retrieve own address from bus level */ 339 if (!addr) 340 sc->pcf_addr = PCF_DEFAULT_ADDR; 341 else 342 sc->pcf_addr = addr; 343 344 pcf_set_S1(sc, PIN); /* initialize S1 */ 345 346 /* own address S'O<>0 */ 347 pcf_set_S0(sc, sc->pcf_addr >> 1); 348 349 /* select clock register */ 350 pcf_set_S1(sc, PIN|ES1); 351 352 /* select bus speed : 18=90kb, 19=45kb, 1A=11kb, 1B=1.5kb */ 353 switch (speed) { 354 case IIC_SLOW: 355 pcf_set_S0(sc, 0x1b); /* XXX Sun uses 0x1f */ 356 break; 357 358 case IIC_FAST: 359 pcf_set_S0(sc, 0x19); /* XXX Sun: 0x1d */ 360 break; 361 362 case IIC_UNKNOWN: 363 case IIC_FASTEST: 364 default: 365 pcf_set_S0(sc, 0x18); /* XXX Sun: 0x1c */ 366 break; 367 } 368 369 /* set bus on, ack=yes, INT=yes */ 370 pcf_set_S1(sc, PIN|ESO|ENI|ACK); 371 372 sc->pcf_slave_mode = SLAVE_RECEIVER; 373 PCF_UNLOCK(sc); 374 375 return (0); 376 } 377 378 int 379 pcf_write(device_t dev, const char *buf, int len, int *sent, int timeout /* us */) 380 { 381 struct pcf_softc *sc = DEVTOSOFTC(dev); 382 int bytes, error = 0; 383 384 #ifdef PCFDEBUG 385 device_printf(dev, " >> writing %d bytes: %#x%s\n", len, 386 (unsigned)buf[0], len > 1? "...": ""); 387 #endif 388 389 bytes = 0; 390 PCF_LOCK(sc); 391 while (len) { 392 pcf_set_S0(sc, *buf++); 393 394 /* wait for the byte to be send */ 395 if ((error = pcf_wait_byte(sc))) 396 goto error; 397 398 /* check if ack received */ 399 if (pcf_noack(sc, timeout)) { 400 error = IIC_ENOACK; 401 goto error; 402 } 403 404 len --; 405 bytes ++; 406 } 407 408 error: 409 *sent = bytes; 410 PCF_UNLOCK(sc); 411 412 #ifdef PCFDEBUG 413 device_printf(dev, " >> %d bytes written (%d)\n", bytes, error); 414 #endif 415 416 return (error); 417 } 418 419 int 420 pcf_read(device_t dev, char *buf, int len, int *read, int last, 421 int delay /* us */) 422 { 423 struct pcf_softc *sc = DEVTOSOFTC(dev); 424 int bytes, error = 0; 425 #ifdef PCFDEBUG 426 char *obuf = buf; 427 428 device_printf(dev, " << reading %d bytes\n", len); 429 #endif 430 431 PCF_LOCK(sc); 432 /* trig the bus to get the first data byte in S0 */ 433 if (len) { 434 if (len == 1 && last) 435 /* just one byte to read */ 436 pcf_set_S1(sc, ESO); /* no ack */ 437 438 dummy_read(sc); 439 } 440 441 bytes = 0; 442 while (len) { 443 /* XXX delay needed here */ 444 445 /* wait for trigged byte */ 446 if ((error = pcf_wait_byte(sc))) { 447 pcf_stop_locked(sc); 448 goto error; 449 } 450 451 if (len == 1 && last) 452 /* ok, last data byte already in S0, no I2C activity 453 * on next pcf_get_S0() */ 454 pcf_stop_locked(sc); 455 456 else if (len == 2 && last) 457 /* next trigged byte with no ack */ 458 pcf_set_S1(sc, ESO); 459 460 /* receive byte, trig next byte */ 461 *buf++ = pcf_get_S0(sc); 462 463 len --; 464 bytes ++; 465 } 466 467 error: 468 *read = bytes; 469 PCF_UNLOCK(sc); 470 471 #ifdef PCFDEBUG 472 device_printf(dev, " << %d bytes read (%d): %#x%s\n", bytes, error, 473 (unsigned)obuf[0], bytes > 1? "...": ""); 474 #endif 475 476 return (error); 477 } 478 479 DRIVER_MODULE(iicbus, pcf, iicbus_driver, 0, 0); 480 MODULE_DEPEND(pcf, iicbus, PCF_MINVER, PCF_PREFVER, PCF_MAXVER); 481 MODULE_VERSION(pcf, PCF_MODVER); 482