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 * $FreeBSD: src/sys/dev/iicbus/iiconf.c,v 1.10 1999/12/03 08:41:02 mdodd Exp $ 27 * $DragonFly: src/sys/bus/iicbus/iiconf.c,v 1.5 2005/06/02 20:40:36 dillon Exp $ 28 * 29 */ 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/malloc.h> 34 #include <sys/module.h> 35 #include <sys/bus.h> 36 #include <sys/thread2.h> 37 38 #include "iiconf.h" 39 #include "iicbus.h" 40 #include "iicbus_if.h" 41 42 /* 43 * iicbus_intr() 44 */ 45 void 46 iicbus_intr(device_t bus, int event, char *buf) 47 { 48 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 49 50 /* call owner's intr routine */ 51 if (sc->owner) 52 IICBUS_INTR(sc->owner, event, buf); 53 54 return; 55 } 56 57 /* 58 * iicbus_alloc_bus() 59 * 60 * Allocate a new bus connected to the given parent device 61 */ 62 device_t 63 iicbus_alloc_bus(device_t parent) 64 { 65 device_t child; 66 67 /* add the bus to the parent */ 68 child = device_add_child(parent, "iicbus", -1); 69 70 return (child); 71 } 72 73 static int 74 iicbus_poll(struct iicbus_softc *sc, int how) 75 { 76 int error; 77 78 switch (how) { 79 case (IIC_WAIT | IIC_INTR): 80 error = tsleep(sc, PCATCH, "iicreq", 0); 81 break; 82 83 case (IIC_WAIT | IIC_NOINTR): 84 error = tsleep(sc, 0, "iicreq", 0); 85 break; 86 87 default: 88 return (EWOULDBLOCK); 89 break; 90 } 91 92 return (error); 93 } 94 95 /* 96 * iicbus_request_bus() 97 * 98 * Allocate the device to perform transfers. 99 * 100 * how : IIC_WAIT or IIC_DONTWAIT 101 */ 102 int 103 iicbus_request_bus(device_t bus, device_t dev, int how) 104 { 105 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 106 int error = 0; 107 108 /* first, ask the underlying layers if the request is ok */ 109 do { 110 error = IICBUS_CALLBACK(device_get_parent(bus), 111 IIC_REQUEST_BUS, (caddr_t)&how); 112 if (error) 113 error = iicbus_poll(sc, how); 114 } while (error == EWOULDBLOCK); 115 116 while (!error) { 117 crit_enter(); 118 if (sc->owner && sc->owner != dev) { 119 crit_exit(); 120 error = iicbus_poll(sc, how); 121 } else { 122 sc->owner = dev; 123 crit_exit(); 124 return (0); 125 } 126 127 /* free any allocated resource */ 128 if (error) 129 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, 130 (caddr_t)&how); 131 } 132 133 return (error); 134 } 135 136 /* 137 * iicbus_release_bus() 138 * 139 * Release the device allocated with iicbus_request_dev() 140 */ 141 int 142 iicbus_release_bus(device_t bus, device_t dev) 143 { 144 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 145 int error; 146 147 /* first, ask the underlying layers if the release is ok */ 148 error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL); 149 150 if (error) 151 return (error); 152 153 crit_enter(); 154 if (sc->owner != dev) { 155 crit_exit(); 156 return (EACCES); 157 } 158 sc->owner = 0; 159 crit_exit(); 160 161 /* wakeup waiting processes */ 162 wakeup(sc); 163 164 return (0); 165 } 166 167 /* 168 * iicbus_started() 169 * 170 * Test if the iicbus is started by the controller 171 */ 172 int 173 iicbus_started(device_t bus) 174 { 175 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 176 177 return (sc->started); 178 } 179 180 /* 181 * iicbus_start() 182 * 183 * Send start condition to the slave addressed by 'slave' 184 */ 185 int 186 iicbus_start(device_t bus, u_char slave, int timeout) 187 { 188 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 189 int error = 0; 190 191 if (sc->started) 192 return (EINVAL); /* bus already started */ 193 194 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout))) 195 sc->started = slave; 196 else 197 sc->started = 0; 198 199 return (error); 200 } 201 202 /* 203 * iicbus_repeated_start() 204 * 205 * Send start condition to the slave addressed by 'slave' 206 */ 207 int 208 iicbus_repeated_start(device_t bus, u_char slave, int timeout) 209 { 210 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 211 int error = 0; 212 213 if (!sc->started) 214 return (EINVAL); /* bus should have been already started */ 215 216 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout))) 217 sc->started = slave; 218 else 219 sc->started = 0; 220 221 return (error); 222 } 223 224 /* 225 * iicbus_stop() 226 * 227 * Send stop condition to the bus 228 */ 229 int 230 iicbus_stop(device_t bus) 231 { 232 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 233 int error = 0; 234 235 if (!sc->started) 236 return (EINVAL); /* bus not started */ 237 238 error = IICBUS_STOP(device_get_parent(bus)); 239 240 /* refuse any further access */ 241 sc->started = 0; 242 243 return (error); 244 } 245 246 /* 247 * iicbus_write() 248 * 249 * Write a block of data to the slave previously started by 250 * iicbus_start() call 251 */ 252 int 253 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout) 254 { 255 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 256 257 /* a slave must have been started with the appropriate address */ 258 if (!sc->started || (sc->started & LSB)) 259 return (EINVAL); 260 261 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout)); 262 } 263 264 /* 265 * iicbus_read() 266 * 267 * Read a block of data from the slave previously started by 268 * iicbus_read() call 269 */ 270 int 271 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay) 272 { 273 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 274 275 /* a slave must have been started with the appropriate address */ 276 if (!sc->started || !(sc->started & LSB)) 277 return (EINVAL); 278 279 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay)); 280 } 281 282 /* 283 * iicbus_write_byte() 284 * 285 * Write a byte to the slave previously started by iicbus_start() call 286 */ 287 int 288 iicbus_write_byte(device_t bus, char byte, int timeout) 289 { 290 char data = byte; 291 int sent; 292 293 return (iicbus_write(bus, &data, 1, &sent, timeout)); 294 } 295 296 /* 297 * iicbus_read_byte() 298 * 299 * Read a byte from the slave previously started by iicbus_start() call 300 */ 301 int 302 iicbus_read_byte(device_t bus, char *byte, int timeout) 303 { 304 int read; 305 306 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout)); 307 } 308 309 /* 310 * iicbus_block_write() 311 * 312 * Write a block of data to slave ; start/stop protocol managed 313 */ 314 int 315 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent) 316 { 317 u_char addr = slave & ~LSB; 318 int error; 319 320 if ((error = iicbus_start(bus, addr, 0))) 321 return (error); 322 323 error = iicbus_write(bus, buf, len, sent, 0); 324 325 iicbus_stop(bus); 326 327 return (error); 328 } 329 330 /* 331 * iicbus_block_read() 332 * 333 * Read a block of data from slave ; start/stop protocol managed 334 */ 335 int 336 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read) 337 { 338 u_char addr = slave | LSB; 339 int error; 340 341 if ((error = iicbus_start(bus, addr, 0))) 342 return (error); 343 344 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0); 345 346 iicbus_stop(bus); 347 348 return (error); 349 } 350 351 /* 352 * iicbus_get_addr() 353 * 354 * Get the I2C 7 bits address of the device 355 */ 356 u_char 357 iicbus_get_addr(device_t dev) 358 { 359 uintptr_t addr; 360 device_t parent = device_get_parent(dev); 361 362 BUS_READ_IVAR(parent, dev, IICBUS_IVAR_ADDR, &addr); 363 364 return ((u_char)addr); 365 } 366 367