1 /* $NetBSD: gttwsi_core.c,v 1.2 2014/11/23 13:37:27 jmcneill Exp $ */ 2 /* 3 * Copyright (c) 2008 Eiji Kawauchi. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed for the NetBSD Project by 17 * Eiji Kawauchi. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 /* 33 * Copyright (c) 2005 Brocade Communcations, inc. 34 * All rights reserved. 35 * 36 * Written by Matt Thomas for Brocade Communcations, Inc. 37 * 38 * Redistribution and use in source and binary forms, with or without 39 * modification, are permitted provided that the following conditions 40 * are met: 41 * 1. Redistributions of source code must retain the above copyright 42 * notice, this list of conditions and the following disclaimer. 43 * 2. Redistributions in binary form must reproduce the above copyright 44 * notice, this list of conditions and the following disclaimer in the 45 * documentation and/or other materials provided with the distribution. 46 * 3. The name of Brocade Communications, Inc. may not be used to endorse 47 * or promote products derived from this software without specific prior 48 * written permission. 49 * 50 * THIS SOFTWARE IS PROVIDED BY BROCADE COMMUNICATIONS, INC. ``AS IS'' AND 51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 53 * ARE DISCLAIMED. IN NO EVENT SHALL EITHER BROCADE COMMUNICATIONS, INC. BE 54 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 55 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 56 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 57 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 58 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 59 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 60 * OF THE POSSIBILITY OF SUCH DAMAGE. 61 */ 62 //#define TWSI_DEBUG 63 64 /* 65 * Marvell Two-Wire Serial Interface (aka I2C) master driver 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: gttwsi_core.c,v 1.2 2014/11/23 13:37:27 jmcneill Exp $"); 70 #include "locators.h" 71 72 #include <sys/param.h> 73 #include <sys/bus.h> 74 #include <sys/condvar.h> 75 #include <sys/device.h> 76 #include <sys/errno.h> 77 #include <sys/kernel.h> 78 #include <sys/mutex.h> 79 #include <sys/systm.h> 80 81 #include <dev/i2c/i2cvar.h> 82 83 #include <dev/i2c/gttwsireg.h> 84 #include <dev/i2c/gttwsivar.h> 85 86 static int gttwsi_acquire_bus(void *, int); 87 static void gttwsi_release_bus(void *, int); 88 static int gttwsi_send_start(void *v, int flags); 89 static int gttwsi_send_stop(void *v, int flags); 90 static int gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags); 91 static int gttwsi_read_byte(void *v, uint8_t *valp, int flags); 92 static int gttwsi_write_byte(void *v, uint8_t val, int flags); 93 94 static int gttwsi_wait(struct gttwsi_softc *, uint32_t, uint32_t, int); 95 96 static inline uint32_t 97 gttwsi_read_4(struct gttwsi_softc *sc, uint32_t reg) 98 { 99 uint32_t val = bus_space_read_4(sc->sc_bust, sc->sc_bush, reg); 100 #ifdef TWSI_DEBUG 101 printf("I2C:R:%02x:%02x\n", reg, val); 102 #else 103 DELAY(TWSI_READ_DELAY); 104 #endif 105 return val; 106 } 107 108 static inline void 109 gttwsi_write_4(struct gttwsi_softc *sc, uint32_t reg, uint32_t val) 110 { 111 bus_space_write_4(sc->sc_bust, sc->sc_bush, reg, val); 112 #ifdef TWSI_DEBUG 113 printf("I2C:W:%02x:%02x\n", reg, val); 114 #else 115 DELAY(TWSI_WRITE_DELAY); 116 #endif 117 return; 118 } 119 120 121 122 /* ARGSUSED */ 123 void 124 gttwsi_attach_subr(device_t self, bus_space_tag_t iot, bus_space_handle_t ioh) 125 { 126 struct gttwsi_softc * const sc = device_private(self); 127 prop_dictionary_t cfg = device_properties(self); 128 129 aprint_naive("\n"); 130 aprint_normal(": Marvell TWSI controller\n"); 131 132 sc->sc_dev = self; 133 sc->sc_bust = iot; 134 sc->sc_bush = ioh; 135 136 mutex_init(&sc->sc_buslock, MUTEX_DEFAULT, IPL_NONE); 137 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_BIO); 138 cv_init(&sc->sc_cv, device_xname(self)); 139 140 prop_dictionary_get_bool(cfg, "iflg-rwc", &sc->sc_iflg_rwc); 141 142 sc->sc_started = false; 143 sc->sc_i2c.ic_cookie = sc; 144 sc->sc_i2c.ic_acquire_bus = gttwsi_acquire_bus; 145 sc->sc_i2c.ic_release_bus = gttwsi_release_bus; 146 sc->sc_i2c.ic_exec = NULL; 147 sc->sc_i2c.ic_send_start = gttwsi_send_start; 148 sc->sc_i2c.ic_send_stop = gttwsi_send_stop; 149 sc->sc_i2c.ic_initiate_xfer = gttwsi_initiate_xfer; 150 sc->sc_i2c.ic_read_byte = gttwsi_read_byte; 151 sc->sc_i2c.ic_write_byte = gttwsi_write_byte; 152 153 /* 154 * Put the controller into Soft Reset. 155 */ 156 /* reset */ 157 gttwsi_write_4(sc, TWSI_SOFTRESET, SOFTRESET_VAL); 158 159 } 160 161 void 162 gttwsi_config_children(device_t self) 163 { 164 struct gttwsi_softc * const sc = device_private(self); 165 struct i2cbus_attach_args iba; 166 167 memset(&iba, 0, sizeof(iba)); 168 iba.iba_tag = &sc->sc_i2c; 169 170 (void) config_found_ia(sc->sc_dev, "i2cbus", &iba, iicbus_print); 171 } 172 173 int 174 gttwsi_intr(void *arg) 175 { 176 struct gttwsi_softc *sc = arg; 177 uint32_t val; 178 179 val = gttwsi_read_4(sc, TWSI_CONTROL); 180 if (val & CONTROL_IFLG) { 181 gttwsi_write_4(sc, TWSI_CONTROL, val & ~CONTROL_INTEN); 182 mutex_enter(&sc->sc_mtx); 183 cv_signal(&sc->sc_cv); 184 mutex_exit(&sc->sc_mtx); 185 186 return 1; /* handled */ 187 } 188 return 0; 189 } 190 191 /* ARGSUSED */ 192 static int 193 gttwsi_acquire_bus(void *arg, int flags) 194 { 195 struct gttwsi_softc *sc = arg; 196 197 mutex_enter(&sc->sc_buslock); 198 return 0; 199 } 200 201 /* ARGSUSED */ 202 static void 203 gttwsi_release_bus(void *arg, int flags) 204 { 205 struct gttwsi_softc *sc = arg; 206 207 mutex_exit(&sc->sc_buslock); 208 } 209 210 static int 211 gttwsi_send_start(void *v, int flags) 212 { 213 struct gttwsi_softc *sc = v; 214 int expect; 215 216 if (sc->sc_started) 217 expect = STAT_RSCT; 218 else 219 expect = STAT_SCT; 220 sc->sc_started = true; 221 return gttwsi_wait(sc, CONTROL_START, expect, flags); 222 } 223 224 static int 225 gttwsi_send_stop(void *v, int flags) 226 { 227 struct gttwsi_softc *sc = v; 228 int retry = TWSI_RETRY_COUNT; 229 uint32_t control; 230 231 sc->sc_started = false; 232 233 /* Interrupt is not generated for STAT_NRS. */ 234 control = CONTROL_STOP | CONTROL_TWSIEN; 235 if (sc->sc_iflg_rwc) 236 control |= CONTROL_IFLG; 237 gttwsi_write_4(sc, TWSI_CONTROL, control); 238 while (retry > 0) { 239 if (gttwsi_read_4(sc, TWSI_STATUS) == STAT_NRS) 240 return 0; 241 retry--; 242 DELAY(TWSI_STAT_DELAY); 243 } 244 245 aprint_error_dev(sc->sc_dev, "send STOP failed\n"); 246 return -1; 247 } 248 249 static int 250 gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags) 251 { 252 struct gttwsi_softc *sc = v; 253 uint32_t data, expect; 254 int error, read; 255 256 gttwsi_send_start(v, flags); 257 258 read = (flags & I2C_F_READ) != 0; 259 if (read) 260 expect = STAT_ARBT_AR; 261 else 262 expect = STAT_AWBT_AR; 263 264 /* 265 * First byte contains whether this xfer is a read or write. 266 */ 267 data = read; 268 if (addr > 0x7f) { 269 /* 270 * If this is a 10bit request, the first address byte is 271 * 0b11110<b9><b8><r/w>. 272 */ 273 data |= 0xf0 | ((addr & 0x300) >> 7); 274 gttwsi_write_4(sc, TWSI_DATA, data); 275 error = gttwsi_wait(sc, 0, expect, flags); 276 if (error) 277 return error; 278 /* 279 * The first address byte has been sent, now to send 280 * the second one. 281 */ 282 if (read) 283 expect = STAT_SARBT_AR; 284 else 285 expect = STAT_SAWBT_AR; 286 data = (uint8_t)addr; 287 } else 288 data |= (addr << 1); 289 290 gttwsi_write_4(sc, TWSI_DATA, data); 291 return gttwsi_wait(sc, 0, expect, flags); 292 } 293 294 static int 295 gttwsi_read_byte(void *v, uint8_t *valp, int flags) 296 { 297 struct gttwsi_softc *sc = v; 298 int error; 299 300 if (flags & I2C_F_LAST) 301 error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, flags); 302 else 303 error = gttwsi_wait(sc, CONTROL_ACK, STAT_MRRD_AT, flags); 304 if (!error) 305 *valp = gttwsi_read_4(sc, TWSI_DATA); 306 if ((flags & (I2C_F_LAST | I2C_F_STOP)) == (I2C_F_LAST | I2C_F_STOP)) 307 error = gttwsi_send_stop(sc, flags); 308 return error; 309 } 310 311 static int 312 gttwsi_write_byte(void *v, uint8_t val, int flags) 313 { 314 struct gttwsi_softc *sc = v; 315 int error; 316 317 gttwsi_write_4(sc, TWSI_DATA, val); 318 error = gttwsi_wait(sc, 0, STAT_MTDB_AR, flags); 319 if (flags & I2C_F_STOP) 320 gttwsi_send_stop(sc, flags); 321 return error; 322 } 323 324 static int 325 gttwsi_wait(struct gttwsi_softc *sc, uint32_t control, uint32_t expect, 326 int flags) 327 { 328 uint32_t status; 329 int timo, error = 0; 330 331 DELAY(5); 332 if (!(flags & I2C_F_POLL)) 333 control |= CONTROL_INTEN; 334 if (sc->sc_iflg_rwc) 335 control |= CONTROL_IFLG; 336 gttwsi_write_4(sc, TWSI_CONTROL, control | CONTROL_TWSIEN); 337 338 timo = 0; 339 for (;;) { 340 control = gttwsi_read_4(sc, TWSI_CONTROL); 341 if (control & CONTROL_IFLG) 342 break; 343 if (!(flags & I2C_F_POLL)) { 344 mutex_enter(&sc->sc_mtx); 345 error = cv_timedwait_sig(&sc->sc_cv, &sc->sc_mtx, hz); 346 mutex_exit(&sc->sc_mtx); 347 if (error) 348 return error; 349 } 350 DELAY(TWSI_RETRY_DELAY); 351 if (timo++ > 1000000) /* 1sec */ 352 break; 353 } 354 355 status = gttwsi_read_4(sc, TWSI_STATUS); 356 if (status != expect) { 357 aprint_error_dev(sc->sc_dev, 358 "unexpected status 0x%x: expect 0x%x\n", status, expect); 359 return EIO; 360 } 361 return error; 362 } 363