gttwsi_core.c revision 1.18
1 /* $NetBSD: gttwsi_core.c,v 1.18 2021/08/07 16:19:11 thorpej 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 1.18 2021/08/07 16:19:11 thorpej 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_send_start(void *v, int flags); 87 static int gttwsi_send_stop(void *v, int flags); 88 static int gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags); 89 static int gttwsi_read_byte(void *v, uint8_t *valp, int flags); 90 static int gttwsi_write_byte(void *v, uint8_t val, int flags); 91 92 static int gttwsi_wait(struct gttwsi_softc *, uint32_t, uint32_t, 93 uint32_t, int, const char *); 94 95 uint32_t 96 gttwsi_read_4(struct gttwsi_softc *sc, uint32_t reg) 97 { 98 const uint32_t val = bus_space_read_4(sc->sc_bust, sc->sc_bush, 99 sc->sc_regmap[reg]); 100 #ifdef TWSI_DEBUG 101 printf("I2C:R:[%" PRIu32 "]%02" PRIxBUSSIZE ":%02" PRIx32 "\n", reg, sc->sc_regmap[reg], val); 102 #else 103 DELAY(TWSI_READ_DELAY); 104 #endif 105 return val; 106 } 107 108 void 109 gttwsi_write_4(struct gttwsi_softc *sc, uint32_t reg, uint32_t val) 110 { 111 112 bus_space_write_4(sc->sc_bust, sc->sc_bush, sc->sc_regmap[reg], val); 113 #ifdef TWSI_DEBUG 114 printf("I2C:W:[%" PRIu32 "]%02" PRIxBUSSIZE ":%02" PRIx32 "\n", reg, sc->sc_regmap[reg], val); 115 #else 116 DELAY(TWSI_WRITE_DELAY); 117 #endif 118 } 119 120 /* ARGSUSED */ 121 void 122 gttwsi_attach_subr(device_t self, bus_space_tag_t iot, bus_space_handle_t ioh, 123 const bus_size_t *regmap) 124 { 125 struct gttwsi_softc * const sc = device_private(self); 126 prop_dictionary_t cfg = device_properties(self); 127 128 aprint_naive("\n"); 129 aprint_normal(": Marvell TWSI controller\n"); 130 131 sc->sc_dev = self; 132 sc->sc_bust = iot; 133 sc->sc_bush = ioh; 134 sc->sc_regmap = regmap; 135 136 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_BIO); 137 cv_init(&sc->sc_cv, device_xname(self)); 138 139 prop_dictionary_get_bool(cfg, "iflg-rwc", &sc->sc_iflg_rwc); 140 141 sc->sc_started = false; 142 iic_tag_init(&sc->sc_i2c); 143 sc->sc_i2c.ic_cookie = sc; 144 sc->sc_i2c.ic_send_start = gttwsi_send_start; 145 sc->sc_i2c.ic_send_stop = gttwsi_send_stop; 146 sc->sc_i2c.ic_initiate_xfer = gttwsi_initiate_xfer; 147 sc->sc_i2c.ic_read_byte = gttwsi_read_byte; 148 sc->sc_i2c.ic_write_byte = gttwsi_write_byte; 149 150 /* 151 * Put the controller into Soft Reset. 152 */ 153 /* reset */ 154 gttwsi_write_4(sc, TWSI_SOFTRESET, SOFTRESET_VAL); 155 } 156 157 void 158 gttwsi_config_children(device_t self) 159 { 160 struct gttwsi_softc * const sc = device_private(self); 161 struct i2cbus_attach_args iba; 162 163 memset(&iba, 0, sizeof(iba)); 164 iba.iba_tag = &sc->sc_i2c; 165 166 config_found(sc->sc_dev, &iba, iicbus_print, 167 CFARGS(.iattr = "i2cbus")); 168 } 169 170 int 171 gttwsi_intr(void *arg) 172 { 173 struct gttwsi_softc *sc = arg; 174 uint32_t val; 175 176 mutex_enter(&sc->sc_mtx); 177 val = gttwsi_read_4(sc, TWSI_CONTROL); 178 if (val & CONTROL_IFLG) { 179 gttwsi_write_4(sc, TWSI_CONTROL, val & ~CONTROL_INTEN); 180 cv_broadcast(&sc->sc_cv); 181 mutex_exit(&sc->sc_mtx); 182 return 1; /* handled */ 183 } 184 mutex_exit(&sc->sc_mtx); 185 return 0; 186 } 187 188 static int 189 gttwsi_send_start(void *v, int flags) 190 { 191 struct gttwsi_softc *sc = v; 192 int expect; 193 194 if (sc->sc_started) 195 expect = STAT_RSCT; 196 else 197 expect = STAT_SCT; 198 sc->sc_started = true; 199 return gttwsi_wait(sc, CONTROL_START, expect, 0, flags, "send-start"); 200 } 201 202 static int 203 gttwsi_send_stop(void *v, int flags) 204 { 205 struct gttwsi_softc *sc = v; 206 int retry = TWSI_RETRY_COUNT; 207 uint32_t control, status; 208 209 sc->sc_started = false; 210 211 /* Interrupt is not generated for STAT_NRS. */ 212 control = CONTROL_STOP | CONTROL_TWSIEN; 213 if (sc->sc_iflg_rwc) 214 control |= CONTROL_IFLG; 215 gttwsi_write_4(sc, TWSI_CONTROL, control); 216 while (retry > 0) { 217 if ((status = gttwsi_read_4(sc, TWSI_STATUS)) == STAT_NRS) 218 return 0; 219 retry--; 220 DELAY(TWSI_STAT_DELAY); 221 } 222 223 aprint_error_dev(sc->sc_dev, "send STOP failed, status=0x%02x\n", 224 status); 225 return EWOULDBLOCK; 226 } 227 228 static int 229 gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags) 230 { 231 struct gttwsi_softc *sc = v; 232 uint32_t data, expect, alt; 233 int error, read; 234 235 error = gttwsi_send_start(v, flags); 236 if (error) 237 return error; 238 239 read = (flags & I2C_F_READ) != 0; 240 if (read) { 241 expect = STAT_ARBT_AR; 242 alt = STAT_ARBT_ANR; 243 } else { 244 expect = STAT_AWBT_AR; 245 alt = STAT_AWBT_ANR; 246 } 247 248 /* 249 * First byte contains whether this xfer is a read or write. 250 */ 251 data = read; 252 if (addr > 0x7f) { 253 /* 254 * If this is a 10bit request, the first address byte is 255 * 0b11110<b9><b8><r/w>. 256 */ 257 data |= 0xf0 | ((addr & 0x300) >> 7); 258 gttwsi_write_4(sc, TWSI_DATA, data); 259 error = gttwsi_wait(sc, 0, expect, alt, flags, "send-addr-10"); 260 if (error) 261 return error; 262 /* 263 * The first address byte has been sent, now to send 264 * the second one. 265 */ 266 if (read) { 267 expect = STAT_SARBT_AR; 268 alt = STAT_SARBT_ANR; 269 } else { 270 expect = STAT_SAWBT_AR; 271 alt = STAT_SAWBT_ANR; 272 } 273 data = (uint8_t)addr; 274 } else 275 data |= (addr << 1); 276 277 gttwsi_write_4(sc, TWSI_DATA, data); 278 return gttwsi_wait(sc, 0, expect, alt, flags, "send-addr"); 279 } 280 281 static int 282 gttwsi_read_byte(void *v, uint8_t *valp, int flags) 283 { 284 struct gttwsi_softc *sc = v; 285 int error; 286 287 if (flags & I2C_F_LAST) { 288 error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, 0, flags, 289 "read-last-byte"); 290 } else { 291 error = gttwsi_wait(sc, CONTROL_ACK, STAT_MRRD_AT, 0, flags, 292 "read-byte"); 293 } 294 if (!error) 295 *valp = gttwsi_read_4(sc, TWSI_DATA); 296 if ((flags & (I2C_F_LAST | I2C_F_STOP)) == (I2C_F_LAST | I2C_F_STOP)) 297 error = gttwsi_send_stop(sc, flags); 298 return error; 299 } 300 301 static int 302 gttwsi_write_byte(void *v, uint8_t val, int flags) 303 { 304 struct gttwsi_softc *sc = v; 305 int error; 306 307 gttwsi_write_4(sc, TWSI_DATA, val); 308 error = gttwsi_wait(sc, 0, STAT_MTDB_AR, 0, flags, "write-byte"); 309 if (flags & I2C_F_STOP) 310 gttwsi_send_stop(sc, flags); 311 return error; 312 } 313 314 static int 315 gttwsi_wait(struct gttwsi_softc *sc, uint32_t control, uint32_t expect, 316 uint32_t alt, int flags, const char *what) 317 { 318 uint32_t status; 319 int timo, error = 0; 320 321 /* 322 * XXX Interrupt-driven mode seems to be horribly broken, 323 * XXX at least on AllWinner implementations. Force polled 324 * XXX mode for now. 325 */ 326 flags |= I2C_F_POLL; 327 328 DELAY(5); 329 if (!(flags & I2C_F_POLL)) 330 control |= CONTROL_INTEN; 331 if (sc->sc_iflg_rwc) 332 control |= CONTROL_IFLG; 333 mutex_enter(&sc->sc_mtx); 334 gttwsi_write_4(sc, TWSI_CONTROL, control | CONTROL_TWSIEN); 335 336 timo = 0; 337 for (;;) { 338 control = gttwsi_read_4(sc, TWSI_CONTROL); 339 if (control & CONTROL_IFLG) 340 break; 341 if (!(flags & I2C_F_POLL)) { 342 error = cv_timedwait(&sc->sc_cv, &sc->sc_mtx, hz); 343 if (error) { 344 break; 345 } 346 } else { 347 DELAY(TWSI_RETRY_DELAY); 348 if (timo++ > 1000000) /* 1sec */ 349 break; 350 } 351 } 352 if ((control & CONTROL_IFLG) == 0) { 353 /* 354 * error is set by the cv_timedwait() call above in the 355 * non-polled case. 356 */ 357 if (flags & I2C_F_POLL) { 358 error = EWOULDBLOCK; 359 } else { 360 KASSERT(error != 0); 361 } 362 aprint_error_dev(sc->sc_dev, 363 "gttwsi_wait(): %s timeout%s, control=0x%x, error=%d\n", 364 what, (flags & I2C_F_POLL) ? " (polled)" : "", 365 control, error); 366 goto end; 367 } 368 status = gttwsi_read_4(sc, TWSI_STATUS); 369 if (status != expect) { 370 /* 371 * In the case of probing for a device, we are expecting 372 * 2 different status codes: the ACK case (device exists), 373 * or the NACK case (device does not exist). We don't 374 * need to report an error in the later case. 375 */ 376 if (alt != 0 && status != alt) 377 aprint_error_dev(sc->sc_dev, 378 "unexpected status 0x%x: expect 0x%x\n", status, 379 expect); 380 error = EIO; 381 } 382 end: 383 mutex_exit(&sc->sc_mtx); 384 return error; 385 } 386
Indexes created Sun Oct 12 05:10:08 GMT 2025