1 /* $NetBSD: gttwsi_core.c,v 1.1 2013/09/06 00:56:12 matt 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 1.1 2013/09/06 00:56:12 matt 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); 127 128 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; 134 135 mutex_init(&sc->sc_buslock, MUTEX_DEFAULT, IPL_NONE); 136 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_BIO); 137 cv_init(&sc->sc_cv, device_xname(self)); 138 139 sc->sc_started = false; 140 sc->sc_i2c.ic_cookie = sc; 141 sc->sc_i2c.ic_acquire_bus = gttwsi_acquire_bus; 142 sc->sc_i2c.ic_release_bus = gttwsi_release_bus; 143 sc->sc_i2c.ic_exec = NULL; 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 } 157 158 void 159 gttwsi_config_children(device_t self) 160 { 161 struct gttwsi_softc * const sc = device_private(self); 162 struct i2cbus_attach_args iba; 163 164 memset(&iba, 0, sizeof(iba)); 165 iba.iba_tag = &sc->sc_i2c; 166 167 (void) config_found_ia(sc->sc_dev, "i2cbus", &iba, iicbus_print); 168 } 169 170 int 171 gttwsi_intr(void *arg) 172 { 173 struct gttwsi_softc *sc = arg; 174 uint32_t val; 175 176 val = gttwsi_read_4(sc, TWSI_CONTROL); 177 if (val & CONTROL_IFLG) { 178 gttwsi_write_4(sc, TWSI_CONTROL, val & ~CONTROL_INTEN); 179 mutex_enter(&sc->sc_mtx); 180 cv_signal(&sc->sc_cv); 181 mutex_exit(&sc->sc_mtx); 182 183 return 1; /* handled */ 184 } 185 return 0; 186 } 187 188 /* ARGSUSED */ 189 static int 190 gttwsi_acquire_bus(void *arg, int flags) 191 { 192 struct gttwsi_softc *sc = arg; 193 194 mutex_enter(&sc->sc_buslock); 195 return 0; 196 } 197 198 /* ARGSUSED */ 199 static void 200 gttwsi_release_bus(void *arg, int flags) 201 { 202 struct gttwsi_softc *sc = arg; 203 204 mutex_exit(&sc->sc_buslock); 205 } 206 207 static int 208 gttwsi_send_start(void *v, int flags) 209 { 210 struct gttwsi_softc *sc = v; 211 int expect; 212 213 if (sc->sc_started) 214 expect = STAT_RSCT; 215 else 216 expect = STAT_SCT; 217 sc->sc_started = true; 218 return gttwsi_wait(sc, CONTROL_START, expect, flags); 219 } 220 221 static int 222 gttwsi_send_stop(void *v, int flags) 223 { 224 struct gttwsi_softc *sc = v; 225 int retry = TWSI_RETRY_COUNT; 226 227 sc->sc_started = false; 228 229 /* Interrupt is not generated for STAT_NRS. */ 230 gttwsi_write_4(sc, TWSI_CONTROL, CONTROL_STOP | CONTROL_TWSIEN); 231 while (retry > 0) { 232 if (gttwsi_read_4(sc, TWSI_STATUS) == STAT_NRS) 233 return 0; 234 retry--; 235 DELAY(TWSI_STAT_DELAY); 236 } 237 238 aprint_error_dev(sc->sc_dev, "send STOP failed\n"); 239 return -1; 240 } 241 242 static int 243 gttwsi_initiate_xfer(void *v, i2c_addr_t addr, int flags) 244 { 245 struct gttwsi_softc *sc = v; 246 uint32_t data, expect; 247 int error, read; 248 249 gttwsi_send_start(v, flags); 250 251 read = (flags & I2C_F_READ) != 0; 252 if (read) 253 expect = STAT_ARBT_AR; 254 else 255 expect = STAT_AWBT_AR; 256 257 /* 258 * First byte contains whether this xfer is a read or write. 259 */ 260 data = read; 261 if (addr > 0x7f) { 262 /* 263 * If this is a 10bit request, the first address byte is 264 * 0b11110<b9><b8><r/w>. 265 */ 266 data |= 0xf0 | ((addr & 0x300) >> 7); 267 gttwsi_write_4(sc, TWSI_DATA, data); 268 error = gttwsi_wait(sc, 0, expect, flags); 269 if (error) 270 return error; 271 /* 272 * The first address byte has been sent, now to send 273 * the second one. 274 */ 275 if (read) 276 expect = STAT_SARBT_AR; 277 else 278 expect = STAT_SAWBT_AR; 279 data = (uint8_t)addr; 280 } else 281 data |= (addr << 1); 282 283 gttwsi_write_4(sc, TWSI_DATA, data); 284 return gttwsi_wait(sc, 0, expect, flags); 285 } 286 287 static int 288 gttwsi_read_byte(void *v, uint8_t *valp, int flags) 289 { 290 struct gttwsi_softc *sc = v; 291 int error; 292 293 if (flags & I2C_F_LAST) 294 error = gttwsi_wait(sc, 0, STAT_MRRD_ANT, flags); 295 else 296 error = gttwsi_wait(sc, CONTROL_ACK, STAT_MRRD_AT, flags); 297 if (!error) 298 *valp = gttwsi_read_4(sc, TWSI_DATA); 299 if ((flags & (I2C_F_LAST | I2C_F_STOP)) == (I2C_F_LAST | I2C_F_STOP)) 300 error = gttwsi_send_stop(sc, flags); 301 return error; 302 } 303 304 static int 305 gttwsi_write_byte(void *v, uint8_t val, int flags) 306 { 307 struct gttwsi_softc *sc = v; 308 int error; 309 310 gttwsi_write_4(sc, TWSI_DATA, val); 311 error = gttwsi_wait(sc, 0, STAT_MTDB_AR, flags); 312 if (flags & I2C_F_STOP) 313 gttwsi_send_stop(sc, flags); 314 return error; 315 } 316 317 static int 318 gttwsi_wait(struct gttwsi_softc *sc, uint32_t control, uint32_t expect, 319 int flags) 320 { 321 uint32_t status; 322 int timo, error = 0; 323 324 DELAY(5); 325 if (!(flags & I2C_F_POLL)) 326 control |= CONTROL_INTEN; 327 gttwsi_write_4(sc, TWSI_CONTROL, control | CONTROL_TWSIEN); 328 329 timo = 0; 330 for (;;) { 331 control = gttwsi_read_4(sc, TWSI_CONTROL); 332 if (control & CONTROL_IFLG) 333 break; 334 if (!(flags & I2C_F_POLL)) { 335 mutex_enter(&sc->sc_mtx); 336 error = cv_timedwait_sig(&sc->sc_cv, &sc->sc_mtx, hz); 337 mutex_exit(&sc->sc_mtx); 338 if (error) 339 return error; 340 } 341 DELAY(TWSI_RETRY_DELAY); 342 if (timo++ > 1000000) /* 1sec */ 343 break; 344 } 345 346 status = gttwsi_read_4(sc, TWSI_STATUS); 347 if (status != expect) { 348 aprint_error_dev(sc->sc_dev, 349 "unexpected status 0x%x: expect 0x%x\n", status, expect); 350 return EIO; 351 } 352 return error; 353 } 354