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 * $FreeBSD$ 27 * 28 */ 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/kernel.h> 32 #include <sys/malloc.h> 33 #include <sys/module.h> 34 #include <sys/bus.h> 35 36 #include <dev/iicbus/iiconf.h> 37 #include <dev/iicbus/iicbus.h> 38 #include "iicbus_if.h" 39 40 /* 41 * iicbus_intr() 42 */ 43 void 44 iicbus_intr(device_t bus, int event, char *buf) 45 { 46 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 47 48 /* call owner's intr routine */ 49 if (sc->owner) 50 IICBUS_INTR(sc->owner, event, buf); 51 52 return; 53 } 54 55 /* 56 * iicbus_alloc_bus() 57 * 58 * Allocate a new bus connected to the given parent device 59 */ 60 device_t 61 iicbus_alloc_bus(device_t parent) 62 { 63 device_t child; 64 65 /* add the bus to the parent */ 66 child = device_add_child(parent, "iicbus", -1); 67 68 return (child); 69 } 70 71 static int 72 iicbus_poll(struct iicbus_softc *sc, int how) 73 { 74 int error; 75 76 switch (how) { 77 case (IIC_WAIT | IIC_INTR): 78 error = tsleep(sc, IICPRI|PCATCH, "iicreq", 0); 79 break; 80 81 case (IIC_WAIT | IIC_NOINTR): 82 error = tsleep(sc, IICPRI, "iicreq", 0); 83 break; 84 85 default: 86 return (EWOULDBLOCK); 87 break; 88 } 89 90 return (error); 91 } 92 93 /* 94 * iicbus_request_bus() 95 * 96 * Allocate the device to perform transfers. 97 * 98 * how : IIC_WAIT or IIC_DONTWAIT 99 */ 100 int 101 iicbus_request_bus(device_t bus, device_t dev, int how) 102 { 103 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 104 int s, error = 0; 105 106 /* first, ask the underlying layers if the request is ok */ 107 do { 108 error = IICBUS_CALLBACK(device_get_parent(bus), 109 IIC_REQUEST_BUS, (caddr_t)&how); 110 if (error) 111 error = iicbus_poll(sc, how); 112 } while (error == EWOULDBLOCK); 113 114 while (!error) { 115 s = splhigh(); 116 if (sc->owner && sc->owner != dev) { 117 splx(s); 118 119 error = iicbus_poll(sc, how); 120 } else { 121 sc->owner = dev; 122 123 splx(s); 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 s, 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 s = splhigh(); 154 if (sc->owner != dev) { 155 splx(s); 156 return (EACCES); 157 } 158 159 sc->owner = 0; 160 splx(s); 161 162 /* wakeup waiting processes */ 163 wakeup(sc); 164 165 return (0); 166 } 167 168 /* 169 * iicbus_started() 170 * 171 * Test if the iicbus is started by the controller 172 */ 173 int 174 iicbus_started(device_t bus) 175 { 176 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 177 178 return (sc->started); 179 } 180 181 /* 182 * iicbus_start() 183 * 184 * Send start condition to the slave addressed by 'slave' 185 */ 186 int 187 iicbus_start(device_t bus, u_char slave, int timeout) 188 { 189 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 190 int error = 0; 191 192 if (sc->started) 193 return (EINVAL); /* bus already started */ 194 195 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout))) 196 sc->started = slave; 197 else 198 sc->started = 0; 199 200 return (error); 201 } 202 203 /* 204 * iicbus_repeated_start() 205 * 206 * Send start condition to the slave addressed by 'slave' 207 */ 208 int 209 iicbus_repeated_start(device_t bus, u_char slave, int timeout) 210 { 211 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 212 int error = 0; 213 214 if (!sc->started) 215 return (EINVAL); /* bus should have been already started */ 216 217 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout))) 218 sc->started = slave; 219 else 220 sc->started = 0; 221 222 return (error); 223 } 224 225 /* 226 * iicbus_stop() 227 * 228 * Send stop condition to the bus 229 */ 230 int 231 iicbus_stop(device_t bus) 232 { 233 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 234 int error = 0; 235 236 if (!sc->started) 237 return (EINVAL); /* bus not started */ 238 239 error = IICBUS_STOP(device_get_parent(bus)); 240 241 /* refuse any further access */ 242 sc->started = 0; 243 244 return (error); 245 } 246 247 /* 248 * iicbus_write() 249 * 250 * Write a block of data to the slave previously started by 251 * iicbus_start() call 252 */ 253 int 254 iicbus_write(device_t bus, char *buf, int len, int *sent, int timeout) 255 { 256 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 257 258 /* a slave must have been started with the appropriate address */ 259 if (!sc->started || (sc->started & LSB)) 260 return (EINVAL); 261 262 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout)); 263 } 264 265 /* 266 * iicbus_read() 267 * 268 * Read a block of data from the slave previously started by 269 * iicbus_read() call 270 */ 271 int 272 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay) 273 { 274 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus); 275 276 /* a slave must have been started with the appropriate address */ 277 if (!sc->started || !(sc->started & LSB)) 278 return (EINVAL); 279 280 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay)); 281 } 282 283 /* 284 * iicbus_write_byte() 285 * 286 * Write a byte to the slave previously started by iicbus_start() call 287 */ 288 int 289 iicbus_write_byte(device_t bus, char byte, int timeout) 290 { 291 char data = byte; 292 int sent; 293 294 return (iicbus_write(bus, &data, 1, &sent, timeout)); 295 } 296 297 /* 298 * iicbus_read_byte() 299 * 300 * Read a byte from the slave previously started by iicbus_start() call 301 */ 302 int 303 iicbus_read_byte(device_t bus, char *byte, int timeout) 304 { 305 int read; 306 307 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout)); 308 } 309 310 /* 311 * iicbus_block_write() 312 * 313 * Write a block of data to slave ; start/stop protocol managed 314 */ 315 int 316 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent) 317 { 318 u_char addr = slave & ~LSB; 319 int error; 320 321 if ((error = iicbus_start(bus, addr, 0))) 322 return (error); 323 324 error = iicbus_write(bus, buf, len, sent, 0); 325 326 iicbus_stop(bus); 327 328 return (error); 329 } 330 331 /* 332 * iicbus_block_read() 333 * 334 * Read a block of data from slave ; start/stop protocol managed 335 */ 336 int 337 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read) 338 { 339 u_char addr = slave | LSB; 340 int error; 341 342 if ((error = iicbus_start(bus, addr, 0))) 343 return (error); 344 345 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0); 346 347 iicbus_stop(bus); 348 349 return (error); 350 } 351 352 /* 353 * iicbus_get_addr() 354 * 355 * Get the I2C 7 bits address of the device 356 */ 357 u_char 358 iicbus_get_addr(device_t dev) 359 { 360 uintptr_t addr; 361 device_t parent = device_get_parent(dev); 362 363 BUS_READ_IVAR(parent, dev, IICBUS_IVAR_ADDR, &addr); 364 365 return ((u_char)addr); 366 } 367 368