1/*- 2 * Copyright (C) 2008-2009 Semihalf, Michal Hajduk 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 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 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/bus.h> 33#include <sys/kernel.h> 34#include <sys/module.h> 35#include <sys/resource.h> 36 37#include <machine/bus.h> 38#include <machine/resource.h> 39#include <sys/rman.h> 40 41#include <sys/lock.h> 42#include <sys/mutex.h> 43 44#include <dev/iicbus/iiconf.h> 45#include <dev/iicbus/iicbus.h> 46#include "iicbus_if.h" 47 48#include <dev/ofw/ofw_bus.h> 49#include <dev/ofw/ofw_bus_subr.h> 50 51#define I2C_ADDR_REG 0x00 /* I2C slave address register */ 52#define I2C_FDR_REG 0x04 /* I2C frequency divider register */ 53#define I2C_CONTROL_REG 0x08 /* I2C control register */ 54#define I2C_STATUS_REG 0x0C /* I2C status register */ 55#define I2C_DATA_REG 0x10 /* I2C data register */ 56#define I2C_DFSRR_REG 0x14 /* I2C Digital Filter Sampling rate */ 57#define I2C_ENABLE 0x80 /* Module enable - interrupt disable */ 58#define I2CSR_RXAK 0x01 /* Received acknowledge */ 59#define I2CSR_MCF (1<<7) /* Data transfer */ 60#define I2CSR_MASS (1<<6) /* Addressed as a slave */ 61#define I2CSR_MBB (1<<5) /* Bus busy */ 62#define I2CSR_MAL (1<<4) /* Arbitration lost */ 63#define I2CSR_SRW (1<<2) /* Slave read/write */ 64#define I2CSR_MIF (1<<1) /* Module interrupt */ 65#define I2CCR_MEN (1<<7) /* Module enable */ 66#define I2CCR_MSTA (1<<5) /* Master/slave mode */ 67#define I2CCR_MTX (1<<4) /* Transmit/receive mode */ 68#define I2CCR_TXAK (1<<3) /* Transfer acknowledge */ 69#define I2CCR_RSTA (1<<2) /* Repeated START */ 70 71#define I2C_BAUD_RATE_FAST 0x31 72#define I2C_BAUD_RATE_DEF 0x3F 73#define I2C_DFSSR_DIV 0x10 74 75#define DEBUG 76#undef DEBUG 77 78#ifdef DEBUG 79#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt,##args); } while (0) 80#else 81#define debugf(fmt, args...) 82#endif 83 84struct i2c_softc { 85 device_t dev; 86 device_t iicbus; 87 struct resource *res; 88 struct mtx mutex; 89 int rid; 90 bus_space_handle_t bsh; 91 bus_space_tag_t bst; 92}; 93 94static int i2c_probe(device_t); 95static int i2c_attach(device_t); 96 97static int i2c_repeated_start(device_t dev, u_char slave, int timeout); 98static int i2c_start(device_t dev, u_char slave, int timeout); 99static int i2c_stop(device_t dev); 100static int i2c_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr); 101static int i2c_read(device_t dev, char *buf, int len, int *read, int last, int delay); 102static int i2c_write(device_t dev, const char *buf, int len, int *sent, int timeout); 103 104static device_method_t i2c_methods[] = { 105 DEVMETHOD(device_probe, i2c_probe), 106 DEVMETHOD(device_attach, i2c_attach), 107 108 DEVMETHOD(iicbus_callback, iicbus_null_callback), 109 DEVMETHOD(iicbus_repeated_start, i2c_repeated_start), 110 DEVMETHOD(iicbus_start, i2c_start), 111 DEVMETHOD(iicbus_stop, i2c_stop), 112 DEVMETHOD(iicbus_reset, i2c_reset), 113 DEVMETHOD(iicbus_read, i2c_read), 114 DEVMETHOD(iicbus_write, i2c_write), 115 DEVMETHOD(iicbus_transfer, iicbus_transfer_gen), 116 117 { 0, 0 } 118}; 119 120static driver_t i2c_driver = { 121 "i2c", 122 i2c_methods, 123 sizeof(struct i2c_softc), 124}; 125static devclass_t i2c_devclass; 126 127DRIVER_MODULE(i2c, simplebus, i2c_driver, i2c_devclass, 0, 0); 128DRIVER_MODULE(iicbus, i2c, iicbus_driver, iicbus_devclass, 0, 0); 129 130static __inline void 131i2c_write_reg(struct i2c_softc *sc, bus_size_t off, uint8_t val) 132{ 133 134 bus_space_write_1(sc->bst, sc->bsh, off, val); 135} 136 137static __inline uint8_t 138i2c_read_reg(struct i2c_softc *sc, bus_size_t off) 139{ 140 141 return (bus_space_read_1(sc->bst, sc->bsh, off)); 142} 143 144static __inline void 145i2c_flag_set(struct i2c_softc *sc, bus_size_t off, uint8_t mask) 146{ 147 uint8_t status; 148 149 status = i2c_read_reg(sc, off); 150 status |= mask; 151 i2c_write_reg(sc, off, status); 152} 153 154static int 155i2c_do_wait(device_t dev, struct i2c_softc *sc, int write, int start) 156{ 157 int err; 158 uint8_t status; 159 160 status = i2c_read_reg(sc, I2C_STATUS_REG); 161 if (status & I2CSR_MIF) { 162 if (write && start && (status & I2CSR_RXAK)) { 163 debugf("no ack %s", start ? 164 "after sending slave address" : ""); 165 err = IIC_ENOACK; 166 goto error; 167 } 168 if (status & I2CSR_MAL) { 169 debugf("arbitration lost"); 170 err = IIC_EBUSERR; 171 goto error; 172 } 173 if (!write && !(status & I2CSR_MCF)) { 174 debugf("transfer unfinished"); 175 err = IIC_EBUSERR; 176 goto error; 177 } 178 } 179 180 return (IIC_NOERR); 181 182error: 183 i2c_write_reg(sc, I2C_STATUS_REG, 0x0); 184 i2c_write_reg(sc, I2C_CONTROL_REG, I2CCR_MEN | I2CCR_TXAK); 185 return (err); 186} 187 188static int 189i2c_probe(device_t dev) 190{ 191 struct i2c_softc *sc; 192 193 if (!ofw_bus_is_compatible(dev, "fsl-i2c")) 194 return (ENXIO); 195 196 sc = device_get_softc(dev); 197 sc->rid = 0; 198 199 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->rid, 200 RF_ACTIVE); 201 if (sc->res == NULL) { 202 device_printf(dev, "could not allocate resources\n"); 203 return (ENXIO); 204 } 205 206 sc->bst = rman_get_bustag(sc->res); 207 sc->bsh = rman_get_bushandle(sc->res); 208 209 /* Enable I2C */ 210 i2c_write_reg(sc, I2C_CONTROL_REG, I2C_ENABLE); 211 bus_release_resource(dev, SYS_RES_MEMORY, sc->rid, sc->res); 212 device_set_desc(dev, "I2C bus controller"); 213 214 return (BUS_PROBE_DEFAULT); 215} 216 217static int 218i2c_attach(device_t dev) 219{ 220 struct i2c_softc *sc; 221 sc = device_get_softc(dev); 222 223 sc->dev = dev; 224 sc->rid = 0; 225 226 mtx_init(&sc->mutex, device_get_nameunit(dev), "I2C", MTX_DEF); 227 228 sc->res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->rid, 229 RF_ACTIVE); 230 if (sc->res == NULL) { 231 device_printf(dev, "could not allocate resources"); 232 mtx_destroy(&sc->mutex); 233 return (ENXIO); 234 } 235 236 sc->bst = rman_get_bustag(sc->res); 237 sc->bsh = rman_get_bushandle(sc->res); 238 239 sc->iicbus = device_add_child(dev, "iicbus", -1); 240 if (sc->iicbus == NULL) { 241 device_printf(dev, "could not add iicbus child"); 242 mtx_destroy(&sc->mutex); 243 return (ENXIO); 244 } 245 246 bus_generic_attach(dev); 247 return (IIC_NOERR); 248} 249static int 250i2c_repeated_start(device_t dev, u_char slave, int timeout) 251{ 252 struct i2c_softc *sc; 253 int error; 254 255 sc = device_get_softc(dev); 256 257 mtx_lock(&sc->mutex); 258 /* Set repeated start condition */ 259 i2c_flag_set(sc, I2C_CONTROL_REG ,I2CCR_RSTA); 260 /* Write target address - LSB is R/W bit */ 261 i2c_write_reg(sc, I2C_DATA_REG, slave); 262 DELAY(1250); 263 264 error = i2c_do_wait(dev, sc, 1, 1); 265 mtx_unlock(&sc->mutex); 266 267 if (error) 268 return (error); 269 270 return (IIC_NOERR); 271} 272 273static int 274i2c_start(device_t dev, u_char slave, int timeout) 275{ 276 struct i2c_softc *sc; 277 uint8_t status; 278 int error; 279 280 sc = device_get_softc(dev); 281 DELAY(1000); 282 283 mtx_lock(&sc->mutex); 284 status = i2c_read_reg(sc, I2C_STATUS_REG); 285 /* Check if bus is idle or busy */ 286 if (status & I2CSR_MBB) { 287 debugf("bus busy"); 288 mtx_unlock(&sc->mutex); 289 i2c_stop(dev); 290 return (IIC_EBUSBSY); 291 } 292 293 /* Set start condition */ 294 i2c_write_reg(sc, I2C_CONTROL_REG, I2CCR_MEN | I2CCR_MSTA | I2CCR_MTX); 295 /* Write target address - LSB is R/W bit */ 296 i2c_write_reg(sc, I2C_DATA_REG, slave); 297 DELAY(1250); 298 299 error = i2c_do_wait(dev, sc, 1, 1); 300 301 mtx_unlock(&sc->mutex); 302 if (error) 303 return (error); 304 305 return (IIC_NOERR); 306} 307 308static int 309i2c_stop(device_t dev) 310{ 311 struct i2c_softc *sc; 312 313 sc = device_get_softc(dev); 314 mtx_lock(&sc->mutex); 315 i2c_write_reg(sc, I2C_CONTROL_REG, I2CCR_MEN | I2CCR_TXAK); 316 DELAY(1000); 317 mtx_unlock(&sc->mutex); 318 319 return (IIC_NOERR); 320} 321 322static int 323i2c_reset(device_t dev, u_char speed, u_char addr, u_char *oldadr) 324{ 325 struct i2c_softc *sc; 326 uint8_t baud_rate; 327 328 sc = device_get_softc(dev); 329 330 switch (speed) { 331 case IIC_FAST: 332 baud_rate = I2C_BAUD_RATE_FAST; 333 break; 334 case IIC_SLOW: 335 case IIC_UNKNOWN: 336 case IIC_FASTEST: 337 default: 338 baud_rate = I2C_BAUD_RATE_DEF; 339 break; 340 } 341 342 mtx_lock(&sc->mutex); 343 i2c_write_reg(sc, I2C_CONTROL_REG, 0x0); 344 i2c_write_reg(sc, I2C_STATUS_REG, 0x0); 345 DELAY(1000); 346 i2c_write_reg(sc, I2C_FDR_REG, baud_rate); 347 i2c_write_reg(sc, I2C_DFSRR_REG, I2C_DFSSR_DIV); 348 i2c_write_reg(sc, I2C_CONTROL_REG, I2C_ENABLE); 349 DELAY(1000); 350 mtx_unlock(&sc->mutex); 351 352 return (IIC_NOERR); 353} 354 355static int 356i2c_read(device_t dev, char *buf, int len, int *read, int last, int delay) 357{ 358 struct i2c_softc *sc; 359 int error; 360 361 sc = device_get_softc(dev); 362 *read = 0; 363 364 mtx_lock(&sc->mutex); 365 if (len) { 366 if (len == 1) 367 i2c_write_reg(sc, I2C_CONTROL_REG, I2CCR_MEN | 368 I2CCR_MSTA | I2CCR_TXAK); 369 370 else 371 i2c_write_reg(sc, I2C_CONTROL_REG, I2CCR_MEN | 372 I2CCR_MSTA); 373 374 /* dummy read */ 375 i2c_read_reg(sc, I2C_DATA_REG); 376 DELAY(1000); 377 } 378 379 while (*read < len) { 380 DELAY(1000); 381 error = i2c_do_wait(dev, sc, 0, 0); 382 if (error) { 383 mtx_unlock(&sc->mutex); 384 return (error); 385 } 386 if ((*read == len - 2) && last) { 387 i2c_write_reg(sc, I2C_CONTROL_REG, I2CCR_MEN | 388 I2CCR_MSTA | I2CCR_TXAK); 389 } 390 391 if ((*read == len - 1) && last) { 392 i2c_write_reg(sc, I2C_CONTROL_REG, I2CCR_MEN | 393 I2CCR_TXAK); 394 } 395 396 *buf++ = i2c_read_reg(sc, I2C_DATA_REG); 397 (*read)++; 398 DELAY(1250); 399 } 400 mtx_unlock(&sc->mutex); 401 402 return (IIC_NOERR); 403} 404 405static int 406i2c_write(device_t dev, const char *buf, int len, int *sent, int timeout) 407{ 408 struct i2c_softc *sc; 409 int error; 410 411 sc = device_get_softc(dev); 412 *sent = 0; 413 414 mtx_lock(&sc->mutex); 415 while (*sent < len) { 416 i2c_write_reg(sc, I2C_DATA_REG, *buf++); 417 DELAY(1250); 418 419 error = i2c_do_wait(dev, sc, 1, 0); 420 if (error) { 421 mtx_unlock(&sc->mutex); 422 return (error); 423 } 424 425 (*sent)++; 426 } 427 mtx_unlock(&sc->mutex); 428 429 return (IIC_NOERR); 430} 431