1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1998 Nicolas Souchu 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/lock.h> 35 #include <sys/malloc.h> 36 #include <sys/module.h> 37 #include <sys/mutex.h> 38 #include <sys/bus.h> 39 40 #include <dev/iicbus/iiconf.h> 41 #include <dev/iicbus/iicbus.h> 42 #include "iicbus_if.h" 43 44 /* 45 * Translate IIC_Exxxxx status values to vaguely-equivelent errno values. 46 */ 47 int 48 iic2errno(int iic_status) 49 { 50 switch (iic_status) { 51 case IIC_NOERR: return (0); 52 case IIC_EBUSERR: return (EALREADY); 53 case IIC_ENOACK: return (EIO); 54 case IIC_ETIMEOUT: return (ETIMEDOUT); 55 case IIC_EBUSBSY: return (EWOULDBLOCK); 56 case IIC_ESTATUS: return (EPROTO); 57 case IIC_EUNDERFLOW: return (EIO); 58 case IIC_EOVERFLOW: return (EOVERFLOW); 59 case IIC_ENOTSUPP: return (EOPNOTSUPP); 60 case IIC_ENOADDR: return (EADDRNOTAVAIL); 61 case IIC_ERESOURCE: return (ENOMEM); 62 default: return (EIO); 63 } 64 } 65 66 /* 67 * iicbus_intr() 68 */ 69 void 70 iicbus_intr(device_t bus, int event, char *buf) 71 { 72 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 73 74 /* call owner's intr routine */ 75 if (sc->owner) 76 IICBUS_INTR(sc->owner, event, buf); 77 78 return; 79 } 80 81 static int 82 iicbus_poll(struct iicbus_softc *sc, int how) 83 { 84 int error; 85 86 IICBUS_ASSERT_LOCKED(sc); 87 switch (how & IIC_INTRWAIT) { 88 case IIC_WAIT | IIC_INTR: 89 error = mtx_sleep(sc, &sc->lock, IICPRI|PCATCH, "iicreq", 0); 90 break; 91 92 case IIC_WAIT | IIC_NOINTR: 93 error = mtx_sleep(sc, &sc->lock, IICPRI, "iicreq", 0); 94 break; 95 96 default: 97 return (IIC_EBUSBSY); 98 } 99 100 return (error); 101 } 102 103 /* 104 * iicbus_request_bus() 105 * 106 * Allocate the device to perform transfers. 107 * 108 * how : IIC_WAIT or IIC_DONTWAIT 109 */ 110 int 111 iicbus_request_bus(device_t bus, device_t dev, int how) 112 { 113 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 114 int error = 0; 115 116 IICBUS_LOCK(sc); 117 118 for (;;) { 119 if (sc->owner == NULL) 120 break; 121 if ((how & IIC_RECURSIVE) && sc->owner == dev) 122 break; 123 if ((error = iicbus_poll(sc, how)) != 0) 124 break; 125 } 126 127 if (error == 0) { 128 ++sc->owncount; 129 if (sc->owner == NULL) { 130 sc->owner = dev; 131 /* 132 * Mark the device busy while it owns the bus, to 133 * prevent detaching the device, bus, or hardware 134 * controller, until ownership is relinquished. 135 */ 136 device_busy(dev); 137 /* 138 * Drop the lock around the call to the bus driver, it 139 * should be allowed to sleep in the IIC_WAIT case. 140 * Drivers might also need to grab locks that would 141 * cause a LOR if our lock is held. 142 */ 143 IICBUS_UNLOCK(sc); 144 /* Ask the underlying layers if the request is ok */ 145 error = IICBUS_CALLBACK(device_get_parent(bus), 146 IIC_REQUEST_BUS, (caddr_t)&how); 147 IICBUS_LOCK(sc); 148 149 if (error != 0) { 150 sc->owner = NULL; 151 sc->owncount = 0; 152 wakeup_one(sc); 153 } 154 } 155 } 156 157 IICBUS_UNLOCK(sc); 158 159 return (error); 160 } 161 162 /* 163 * iicbus_release_bus() 164 * 165 * Release the device allocated with iicbus_request_dev() 166 */ 167 int 168 iicbus_release_bus(device_t bus, device_t dev) 169 { 170 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 171 172 IICBUS_LOCK(sc); 173 174 if (sc->owner != dev) { 175 IICBUS_UNLOCK(sc); 176 return (IIC_EBUSBSY); 177 } 178 179 if (--sc->owncount == 0) { 180 /* Drop the lock while informing the low-level driver. */ 181 IICBUS_UNLOCK(sc); 182 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL); 183 IICBUS_LOCK(sc); 184 sc->owner = NULL; 185 wakeup_one(sc); 186 device_unbusy(dev); 187 } 188 IICBUS_UNLOCK(sc); 189 return (0); 190 } 191 192 /* 193 * iicbus_started() 194 * 195 * Test if the iicbus is started by the controller 196 */ 197 int 198 iicbus_started(device_t bus) 199 { 200 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 201 202 return (sc->started); 203 } 204 205 /* 206 * iicbus_start() 207 * 208 * Send start condition to the slave addressed by 'slave' 209 */ 210 int 211 iicbus_start(device_t bus, u_char slave, int timeout) 212 { 213 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 214 int error = 0; 215 216 if (sc->started) 217 return (IIC_ESTATUS); /* protocol error, bus already started */ 218 219 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout))) 220 sc->started = slave; 221 else 222 sc->started = 0; 223 224 return (error); 225 } 226 227 /* 228 * iicbus_repeated_start() 229 * 230 * Send start condition to the slave addressed by 'slave' 231 */ 232 int 233 iicbus_repeated_start(device_t bus, u_char slave, int timeout) 234 { 235 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 236 int error = 0; 237 238 if (!sc->started) 239 return (IIC_ESTATUS); /* protocol error, bus not started */ 240 241 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout))) 242 sc->started = slave; 243 else 244 sc->started = 0; 245 246 return (error); 247 } 248 249 /* 250 * iicbus_stop() 251 * 252 * Send stop condition to the bus 253 */ 254 int 255 iicbus_stop(device_t bus) 256 { 257 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 258 int error = 0; 259 260 if (!sc->started) 261 return (IIC_ESTATUS); /* protocol error, bus not started */ 262 263 error = IICBUS_STOP(device_get_parent(bus)); 264 265 /* refuse any further access */ 266 sc->started = 0; 267 268 return (error); 269 } 270 271 /* 272 * iicbus_write() 273 * 274 * Write a block of data to the slave previously started by 275 * iicbus_start() call 276 */ 277 int 278 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout) 279 { 280 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 281 282 /* a slave must have been started for writing */ 283 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0)) 284 return (IIC_ESTATUS); 285 286 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout)); 287 } 288 289 /* 290 * iicbus_read() 291 * 292 * Read a block of data from the slave previously started by 293 * iicbus_read() call 294 */ 295 int 296 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay) 297 { 298 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 299 300 /* a slave must have been started for reading */ 301 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0)) 302 return (IIC_ESTATUS); 303 304 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay)); 305 } 306 307 /* 308 * iicbus_write_byte() 309 * 310 * Write a byte to the slave previously started by iicbus_start() call 311 */ 312 int 313 iicbus_write_byte(device_t bus, char byte, int timeout) 314 { 315 struct iicbus_softc *sc = device_get_softc(bus); 316 char data = byte; 317 int sent; 318 319 /* a slave must have been started for writing */ 320 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0)) 321 return (IIC_ESTATUS); 322 323 return (iicbus_write(bus, &data, 1, &sent, timeout)); 324 } 325 326 /* 327 * iicbus_read_byte() 328 * 329 * Read a byte from the slave previously started by iicbus_start() call 330 */ 331 int 332 iicbus_read_byte(device_t bus, char *byte, int timeout) 333 { 334 struct iicbus_softc *sc = device_get_softc(bus); 335 int read; 336 337 /* a slave must have been started for reading */ 338 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0)) 339 return (IIC_ESTATUS); 340 341 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout)); 342 } 343 344 /* 345 * iicbus_block_write() 346 * 347 * Write a block of data to slave ; start/stop protocol managed 348 */ 349 int 350 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent) 351 { 352 u_char addr = slave & ~LSB; 353 int error; 354 355 if ((error = iicbus_start(bus, addr, 0))) 356 return (error); 357 358 error = iicbus_write(bus, buf, len, sent, 0); 359 360 iicbus_stop(bus); 361 362 return (error); 363 } 364 365 /* 366 * iicbus_block_read() 367 * 368 * Read a block of data from slave ; start/stop protocol managed 369 */ 370 int 371 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read) 372 { 373 u_char addr = slave | LSB; 374 int error; 375 376 if ((error = iicbus_start(bus, addr, 0))) 377 return (error); 378 379 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0); 380 381 iicbus_stop(bus); 382 383 return (error); 384 } 385 386 /* 387 * iicbus_transfer() 388 * 389 * Do an aribtrary number of transfers on the iicbus. We pass these 390 * raw requests to the bridge driver. If the bridge driver supports 391 * them directly, then it manages all the details. If not, it can use 392 * the helper function iicbus_transfer_gen() which will do the 393 * transfers at a low level. 394 * 395 * Pointers passed in as part of iic_msg must be kernel pointers. 396 * Callers that have user addresses to manage must do so on their own. 397 */ 398 int 399 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs) 400 { 401 402 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs)); 403 } 404 405 int 406 iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs, 407 int how) 408 { 409 device_t bus; 410 int error; 411 412 bus = device_get_parent(dev); 413 error = iicbus_request_bus(bus, dev, how); 414 if (error == 0) 415 error = IICBUS_TRANSFER(bus, msgs, nmsgs); 416 iicbus_release_bus(bus, dev); 417 return (error); 418 } 419 420 /* 421 * Generic version of iicbus_transfer that calls the appropriate 422 * routines to accomplish this. See note above about acceptable 423 * buffer addresses. 424 */ 425 int 426 iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs) 427 { 428 int i, error, lenread, lenwrote, nkid, rpstart, addr; 429 device_t *children, bus; 430 bool started; 431 432 if ((error = device_get_children(dev, &children, &nkid)) != 0) 433 return (IIC_ERESOURCE); 434 if (nkid != 1) { 435 free(children, M_TEMP); 436 return (IIC_ENOTSUPP); 437 } 438 bus = children[0]; 439 rpstart = 0; 440 free(children, M_TEMP); 441 started = false; 442 for (i = 0, error = 0; i < nmsgs && error == 0; i++) { 443 addr = msgs[i].slave; 444 if (msgs[i].flags & IIC_M_RD) 445 addr |= LSB; 446 else 447 addr &= ~LSB; 448 449 if (!(msgs[i].flags & IIC_M_NOSTART)) { 450 if (rpstart) 451 error = iicbus_repeated_start(bus, addr, 0); 452 else 453 error = iicbus_start(bus, addr, 0); 454 if (error != 0) 455 break; 456 started = true; 457 } 458 459 if (msgs[i].flags & IIC_M_RD) 460 error = iicbus_read(bus, msgs[i].buf, msgs[i].len, 461 &lenread, IIC_LAST_READ, 0); 462 else 463 error = iicbus_write(bus, msgs[i].buf, msgs[i].len, 464 &lenwrote, 0); 465 if (error != 0) 466 break; 467 468 if (!(msgs[i].flags & IIC_M_NOSTOP)) { 469 rpstart = 0; 470 iicbus_stop(bus); 471 } else { 472 rpstart = 1; /* Next message gets repeated start */ 473 } 474 } 475 if (error != 0 && started) 476 iicbus_stop(bus); 477 return (error); 478 } 479 480 int 481 iicdev_readfrom(device_t slavedev, uint8_t regaddr, void *buffer, 482 uint16_t buflen, int waithow) 483 { 484 struct iic_msg msgs[2]; 485 uint8_t slaveaddr; 486 487 /* 488 * Two transfers back to back with a repeat-start between them; first we 489 * write the address-within-device, then we read from the device. 490 */ 491 slaveaddr = iicbus_get_addr(slavedev); 492 493 msgs[0].slave = slaveaddr; 494 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP; 495 msgs[0].len = 1; 496 msgs[0].buf = ®addr; 497 498 msgs[1].slave = slaveaddr; 499 msgs[1].flags = IIC_M_RD; 500 msgs[1].len = buflen; 501 msgs[1].buf = buffer; 502 503 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow)); 504 } 505 506 int iicdev_writeto(device_t slavedev, uint8_t regaddr, void *buffer, 507 uint16_t buflen, int waithow) 508 { 509 struct iic_msg msgs[2]; 510 uint8_t slaveaddr; 511 512 /* 513 * Two transfers back to back with no stop or start between them; first 514 * we write the address then we write the data to that address, all in a 515 * single transfer from two scattered buffers. 516 */ 517 slaveaddr = iicbus_get_addr(slavedev); 518 519 msgs[0].slave = slaveaddr; 520 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP; 521 msgs[0].len = 1; 522 msgs[0].buf = ®addr; 523 524 msgs[1].slave = slaveaddr; 525 msgs[1].flags = IIC_M_WR | IIC_M_NOSTART; 526 msgs[1].len = buflen; 527 msgs[1].buf = buffer; 528 529 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow)); 530 } 531