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/module.h> 33 #include <sys/bus.h> 34 35 #include <dev/iicbus/iiconf.h> 36 #include <dev/iicbus/iicbus.h> 37 #include "iicbus_if.h" 38 39 /* 40 * iicbus_intr() 41 */ 42 void 43 iicbus_intr(device_t bus, int event, char *buf) 44 { 45 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 46 47 /* call owner's intr routine */ 48 if (sc->owner) 49 IICBUS_INTR(sc->owner, event, buf); 50 51 return; 52 } 53 54 static int 55 iicbus_poll(struct iicbus_softc *sc, int how) 56 { 57 int error; 58 59 switch (how) { 60 case (IIC_WAIT | IIC_INTR): 61 error = tsleep(sc, IICPRI|PCATCH, "iicreq", 0); 62 break; 63 64 case (IIC_WAIT | IIC_NOINTR): 65 error = tsleep(sc, IICPRI, "iicreq", 0); 66 break; 67 68 default: 69 return (EWOULDBLOCK); 70 break; 71 } 72 73 return (error); 74 } 75 76 /* 77 * iicbus_request_bus() 78 * 79 * Allocate the device to perform transfers. 80 * 81 * how : IIC_WAIT or IIC_DONTWAIT 82 */ 83 int 84 iicbus_request_bus(device_t bus, device_t dev, int how) 85 { 86 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 87 int s, error = 0; 88 89 /* first, ask the underlying layers if the request is ok */ 90 do { 91 error = IICBUS_CALLBACK(device_get_parent(bus), 92 IIC_REQUEST_BUS, (caddr_t)&how); 93 if (error) 94 error = iicbus_poll(sc, how); 95 } while (error == EWOULDBLOCK); 96 97 while (!error) { 98 s = splhigh(); 99 if (sc->owner && sc->owner != dev) { 100 splx(s); 101 102 error = iicbus_poll(sc, how); 103 } else { 104 sc->owner = dev; 105 106 splx(s); 107 return (0); 108 } 109 110 /* free any allocated resource */ 111 if (error) 112 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, 113 (caddr_t)&how); 114 } 115 116 return (error); 117 } 118 119 /* 120 * iicbus_release_bus() 121 * 122 * Release the device allocated with iicbus_request_dev() 123 */ 124 int 125 iicbus_release_bus(device_t bus, device_t dev) 126 { 127 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 128 int s, error; 129 130 /* first, ask the underlying layers if the release is ok */ 131 error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL); 132 133 if (error) 134 return (error); 135 136 s = splhigh(); 137 if (sc->owner != dev) { 138 splx(s); 139 return (EACCES); 140 } 141 142 sc->owner = 0; 143 splx(s); 144 145 /* wakeup waiting processes */ 146 wakeup(sc); 147 148 return (0); 149 } 150 151 /* 152 * iicbus_started() 153 * 154 * Test if the iicbus is started by the controller 155 */ 156 int 157 iicbus_started(device_t bus) 158 { 159 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 160 161 return (sc->started); 162 } 163 164 /* 165 * iicbus_start() 166 * 167 * Send start condition to the slave addressed by 'slave' 168 */ 169 int 170 iicbus_start(device_t bus, u_char slave, int timeout) 171 { 172 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 173 int error = 0; 174 175 if (sc->started) 176 return (EINVAL); /* bus already started */ 177 178 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout))) 179 sc->started = slave; 180 else 181 sc->started = 0; 182 183 return (error); 184 } 185 186 /* 187 * iicbus_repeated_start() 188 * 189 * Send start condition to the slave addressed by 'slave' 190 */ 191 int 192 iicbus_repeated_start(device_t bus, u_char slave, int timeout) 193 { 194 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 195 int error = 0; 196 197 if (!sc->started) 198 return (EINVAL); /* bus should have been already started */ 199 200 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout))) 201 sc->started = slave; 202 else 203 sc->started = 0; 204 205 return (error); 206 } 207 208 /* 209 * iicbus_stop() 210 * 211 * Send stop condition to the bus 212 */ 213 int 214 iicbus_stop(device_t bus) 215 { 216 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 217 int error = 0; 218 219 if (!sc->started) 220 return (EINVAL); /* bus not started */ 221 222 error = IICBUS_STOP(device_get_parent(bus)); 223 224 /* refuse any further access */ 225 sc->started = 0; 226 227 return (error); 228 } 229 230 /* 231 * iicbus_write() 232 * 233 * Write a block of data to the slave previously started by 234 * iicbus_start() call 235 */ 236 int 237 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout) 238 { 239 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 240 241 /* a slave must have been started with the appropriate address */ 242 if (!sc->started || (sc->started & LSB)) 243 return (EINVAL); 244 245 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout)); 246 } 247 248 /* 249 * iicbus_read() 250 * 251 * Read a block of data from the slave previously started by 252 * iicbus_read() call 253 */ 254 int 255 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay) 256 { 257 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 258 259 /* a slave must have been started with the appropriate address */ 260 if (!sc->started || !(sc->started & LSB)) 261 return (EINVAL); 262 263 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay)); 264 } 265 266 /* 267 * iicbus_write_byte() 268 * 269 * Write a byte to the slave previously started by iicbus_start() call 270 */ 271 int 272 iicbus_write_byte(device_t bus, char byte, int timeout) 273 { 274 char data = byte; 275 int sent; 276 277 return (iicbus_write(bus, &data, 1, &sent, timeout)); 278 } 279 280 /* 281 * iicbus_read_byte() 282 * 283 * Read a byte from the slave previously started by iicbus_start() call 284 */ 285 int 286 iicbus_read_byte(device_t bus, char *byte, int timeout) 287 { 288 int read; 289 290 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout)); 291 } 292 293 /* 294 * iicbus_block_write() 295 * 296 * Write a block of data to slave ; start/stop protocol managed 297 */ 298 int 299 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent) 300 { 301 u_char addr = slave & ~LSB; 302 int error; 303 304 if ((error = iicbus_start(bus, addr, 0))) 305 return (error); 306 307 error = iicbus_write(bus, buf, len, sent, 0); 308 309 iicbus_stop(bus); 310 311 return (error); 312 } 313 314 /* 315 * iicbus_block_read() 316 * 317 * Read a block of data from slave ; start/stop protocol managed 318 */ 319 int 320 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read) 321 { 322 u_char addr = slave | LSB; 323 int error; 324 325 if ((error = iicbus_start(bus, addr, 0))) 326 return (error); 327 328 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0); 329 330 iicbus_stop(bus); 331 332 return (error); 333 } 334 335 /* 336 * iicbus_trasnfer() 337 * 338 * Do an aribtrary number of transfers on the iicbus. We pass these 339 * raw requests to the bridge driver. If the bridge driver supports 340 * them directly, then it manages all the details. If not, it can use 341 * the helper function iicbus_transfer_gen() which will do the 342 * transfers at a low level. 343 * 344 * Pointers passed in as part of iic_msg must be kernel pointers. 345 * Callers that have user addresses to manage must do so on their own. 346 */ 347 int 348 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs) 349 { 350 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs)); 351 } 352 353 /* 354 * Generic version of iicbus_transfer that calls the appropriate 355 * routines to accomplish this. See note above about acceptable 356 * buffer addresses. 357 */ 358 int 359 iicbus_transfer_gen(device_t bus, struct iic_msg *msgs, uint32_t nmsgs) 360 { 361 int i, error, max, lenread, lenwrote; 362 363 for (i = 0, max = 0; i < nmsgs; i++) 364 if (max < msgs[i].len) 365 max = msgs[i].len; 366 for (i = 0, error = 0; i < nmsgs && error == 0; i++) { 367 if (msgs[i].flags & IIC_M_RD) 368 error = iicbus_block_read(bus, msgs[i].slave, 369 msgs[i].buf, msgs[i].len, &lenread); 370 else 371 error = iicbus_block_write(bus, msgs[i].slave, 372 msgs[i].buf, msgs[i].len, &lenwrote); 373 } 374 return (error); 375 } 376