1 /*- 2 * Copyright (c) 1998 Nicolas Souchu 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("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/lock.h> 33 #include <sys/malloc.h> 34 #include <sys/module.h> 35 #include <sys/mutex.h> 36 #include <sys/bus.h> 37 38 #include <dev/iicbus/iiconf.h> 39 #include <dev/iicbus/iicbus.h> 40 #include "iicbus_if.h" 41 42 /* 43 * Translate IIC_Exxxxx status values to vaguely-equivelent errno values. 44 */ 45 int 46 iic2errno(int iic_status) 47 { 48 switch (iic_status) { 49 case IIC_NOERR: return (0); 50 case IIC_EBUSERR: return (EALREADY); 51 case IIC_ENOACK: return (EIO); 52 case IIC_ETIMEOUT: return (ETIMEDOUT); 53 case IIC_EBUSBSY: return (EWOULDBLOCK); 54 case IIC_ESTATUS: return (EPROTO); 55 case IIC_EUNDERFLOW: return (EIO); 56 case IIC_EOVERFLOW: return (EOVERFLOW); 57 case IIC_ENOTSUPP: return (EOPNOTSUPP); 58 case IIC_ENOADDR: return (EADDRNOTAVAIL); 59 case IIC_ERESOURCE: return (ENOMEM); 60 default: return (EIO); 61 } 62 } 63 64 /* 65 * iicbus_intr() 66 */ 67 void 68 iicbus_intr(device_t bus, int event, char *buf) 69 { 70 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 71 72 /* call owner's intr routine */ 73 if (sc->owner) 74 IICBUS_INTR(sc->owner, event, buf); 75 76 return; 77 } 78 79 static int 80 iicbus_poll(struct iicbus_softc *sc, int how) 81 { 82 int error; 83 84 IICBUS_ASSERT_LOCKED(sc); 85 switch (how) { 86 case IIC_WAIT | IIC_INTR: 87 error = mtx_sleep(sc, &sc->lock, IICPRI|PCATCH, "iicreq", 0); 88 break; 89 90 case IIC_WAIT | IIC_NOINTR: 91 error = mtx_sleep(sc, &sc->lock, IICPRI, "iicreq", 0); 92 break; 93 94 default: 95 return (IIC_EBUSBSY); 96 } 97 98 return (error); 99 } 100 101 /* 102 * iicbus_request_bus() 103 * 104 * Allocate the device to perform transfers. 105 * 106 * how : IIC_WAIT or IIC_DONTWAIT 107 */ 108 int 109 iicbus_request_bus(device_t bus, device_t dev, int how) 110 { 111 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 112 int error = 0; 113 114 IICBUS_LOCK(sc); 115 116 while ((error == 0) && (sc->owner != NULL)) 117 error = iicbus_poll(sc, how); 118 119 if (error == 0) { 120 sc->owner = dev; 121 /* 122 * Drop the lock around the call to the bus driver. 123 * This call should be allowed to sleep in the IIC_WAIT case. 124 * Drivers might also need to grab locks that would cause LOR 125 * if our lock is held. 126 */ 127 IICBUS_UNLOCK(sc); 128 /* Ask the underlying layers if the request is ok */ 129 error = IICBUS_CALLBACK(device_get_parent(bus), 130 IIC_REQUEST_BUS, (caddr_t)&how); 131 IICBUS_LOCK(sc); 132 133 if (error != 0) { 134 sc->owner = NULL; 135 wakeup_one(sc); 136 } 137 } 138 139 140 IICBUS_UNLOCK(sc); 141 142 return (error); 143 } 144 145 /* 146 * iicbus_release_bus() 147 * 148 * Release the device allocated with iicbus_request_dev() 149 */ 150 int 151 iicbus_release_bus(device_t bus, device_t dev) 152 { 153 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 154 int error; 155 156 IICBUS_LOCK(sc); 157 158 if (sc->owner != dev) { 159 IICBUS_UNLOCK(sc); 160 return (IIC_EBUSBSY); 161 } 162 163 /* 164 * Drop the lock around the call to the bus driver. 165 * This call should be allowed to sleep in the IIC_WAIT case. 166 * Drivers might also need to grab locks that would cause LOR 167 * if our lock is held. 168 */ 169 IICBUS_UNLOCK(sc); 170 /* Ask the underlying layers if the release is ok */ 171 error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL); 172 173 if (error == 0) { 174 IICBUS_LOCK(sc); 175 sc->owner = NULL; 176 177 /* wakeup a waiting thread */ 178 wakeup_one(sc); 179 IICBUS_UNLOCK(sc); 180 } 181 182 return (error); 183 } 184 185 /* 186 * iicbus_started() 187 * 188 * Test if the iicbus is started by the controller 189 */ 190 int 191 iicbus_started(device_t bus) 192 { 193 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 194 195 return (sc->started); 196 } 197 198 /* 199 * iicbus_start() 200 * 201 * Send start condition to the slave addressed by 'slave' 202 */ 203 int 204 iicbus_start(device_t bus, u_char slave, int timeout) 205 { 206 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 207 int error = 0; 208 209 if (sc->started) 210 return (IIC_ESTATUS); /* protocol error, bus already started */ 211 212 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout))) 213 sc->started = slave; 214 else 215 sc->started = 0; 216 217 return (error); 218 } 219 220 /* 221 * iicbus_repeated_start() 222 * 223 * Send start condition to the slave addressed by 'slave' 224 */ 225 int 226 iicbus_repeated_start(device_t bus, u_char slave, int timeout) 227 { 228 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 229 int error = 0; 230 231 if (!sc->started) 232 return (IIC_ESTATUS); /* protocol error, bus not started */ 233 234 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout))) 235 sc->started = slave; 236 else 237 sc->started = 0; 238 239 return (error); 240 } 241 242 /* 243 * iicbus_stop() 244 * 245 * Send stop condition to the bus 246 */ 247 int 248 iicbus_stop(device_t bus) 249 { 250 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 251 int error = 0; 252 253 if (!sc->started) 254 return (IIC_ESTATUS); /* protocol error, bus not started */ 255 256 error = IICBUS_STOP(device_get_parent(bus)); 257 258 /* refuse any further access */ 259 sc->started = 0; 260 261 return (error); 262 } 263 264 /* 265 * iicbus_write() 266 * 267 * Write a block of data to the slave previously started by 268 * iicbus_start() call 269 */ 270 int 271 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout) 272 { 273 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 274 275 /* a slave must have been started for writing */ 276 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0)) 277 return (IIC_ESTATUS); 278 279 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout)); 280 } 281 282 /* 283 * iicbus_read() 284 * 285 * Read a block of data from the slave previously started by 286 * iicbus_read() call 287 */ 288 int 289 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay) 290 { 291 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 292 293 /* a slave must have been started for reading */ 294 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0)) 295 return (IIC_ESTATUS); 296 297 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay)); 298 } 299 300 /* 301 * iicbus_write_byte() 302 * 303 * Write a byte to the slave previously started by iicbus_start() call 304 */ 305 int 306 iicbus_write_byte(device_t bus, char byte, int timeout) 307 { 308 struct iicbus_softc *sc = device_get_softc(bus); 309 char data = byte; 310 int sent; 311 312 /* a slave must have been started for writing */ 313 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0)) 314 return (IIC_ESTATUS); 315 316 return (iicbus_write(bus, &data, 1, &sent, timeout)); 317 } 318 319 /* 320 * iicbus_read_byte() 321 * 322 * Read a byte from the slave previously started by iicbus_start() call 323 */ 324 int 325 iicbus_read_byte(device_t bus, char *byte, int timeout) 326 { 327 struct iicbus_softc *sc = device_get_softc(bus); 328 int read; 329 330 /* a slave must have been started for reading */ 331 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0)) 332 return (IIC_ESTATUS); 333 334 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout)); 335 } 336 337 /* 338 * iicbus_block_write() 339 * 340 * Write a block of data to slave ; start/stop protocol managed 341 */ 342 int 343 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent) 344 { 345 u_char addr = slave & ~LSB; 346 int error; 347 348 if ((error = iicbus_start(bus, addr, 0))) 349 return (error); 350 351 error = iicbus_write(bus, buf, len, sent, 0); 352 353 iicbus_stop(bus); 354 355 return (error); 356 } 357 358 /* 359 * iicbus_block_read() 360 * 361 * Read a block of data from slave ; start/stop protocol managed 362 */ 363 int 364 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read) 365 { 366 u_char addr = slave | LSB; 367 int error; 368 369 if ((error = iicbus_start(bus, addr, 0))) 370 return (error); 371 372 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0); 373 374 iicbus_stop(bus); 375 376 return (error); 377 } 378 379 /* 380 * iicbus_transfer() 381 * 382 * Do an aribtrary number of transfers on the iicbus. We pass these 383 * raw requests to the bridge driver. If the bridge driver supports 384 * them directly, then it manages all the details. If not, it can use 385 * the helper function iicbus_transfer_gen() which will do the 386 * transfers at a low level. 387 * 388 * Pointers passed in as part of iic_msg must be kernel pointers. 389 * Callers that have user addresses to manage must do so on their own. 390 */ 391 int 392 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs) 393 { 394 395 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs)); 396 } 397 398 int 399 iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs, 400 int how) 401 { 402 device_t bus; 403 int error; 404 405 bus = device_get_parent(dev); 406 error = iicbus_request_bus(bus, dev, how); 407 if (error == 0) 408 error = IICBUS_TRANSFER(bus, msgs, nmsgs); 409 iicbus_release_bus(bus, dev); 410 return (error); 411 } 412 413 /* 414 * Generic version of iicbus_transfer that calls the appropriate 415 * routines to accomplish this. See note above about acceptable 416 * buffer addresses. 417 */ 418 int 419 iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs) 420 { 421 int i, error, lenread, lenwrote, nkid, rpstart, addr; 422 device_t *children, bus; 423 bool nostop; 424 425 if ((error = device_get_children(dev, &children, &nkid)) != 0) 426 return (IIC_ERESOURCE); 427 if (nkid != 1) { 428 free(children, M_TEMP); 429 return (IIC_ENOTSUPP); 430 } 431 bus = children[0]; 432 rpstart = 0; 433 free(children, M_TEMP); 434 nostop = iicbus_get_nostop(dev); 435 for (i = 0, error = 0; i < nmsgs && error == 0; i++) { 436 addr = msgs[i].slave; 437 if (msgs[i].flags & IIC_M_RD) 438 addr |= LSB; 439 else 440 addr &= ~LSB; 441 442 if (!(msgs[i].flags & IIC_M_NOSTART)) { 443 if (rpstart) 444 error = iicbus_repeated_start(bus, addr, 0); 445 else 446 error = iicbus_start(bus, addr, 0); 447 } 448 if (error != 0) 449 break; 450 451 if (msgs[i].flags & IIC_M_RD) 452 error = iicbus_read(bus, msgs[i].buf, msgs[i].len, 453 &lenread, IIC_LAST_READ, 0); 454 else 455 error = iicbus_write(bus, msgs[i].buf, msgs[i].len, 456 &lenwrote, 0); 457 if (error != 0) 458 break; 459 460 if ((msgs[i].flags & IIC_M_NOSTOP) != 0 || 461 (nostop && i + 1 < nmsgs)) { 462 rpstart = 1; /* Next message gets repeated start */ 463 } else { 464 rpstart = 0; 465 iicbus_stop(bus); 466 } 467 } 468 if (error != 0 && !nostop) 469 iicbus_stop(bus); 470 return (error); 471 } 472