bcm2835_bsc.c revision 1.6
1 /* $NetBSD: bcm2835_bsc.c,v 1.6 2017/06/17 17:03:40 jmcneill Exp $ */ 2 3 /* 4 * Copyright (c) 2012 Jonathan A. Kollasch 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 20 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 21 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 25 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 26 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: bcm2835_bsc.c,v 1.6 2017/06/17 17:03:40 jmcneill Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/bus.h> 34 #include <sys/device.h> 35 #include <sys/intr.h> 36 #include <sys/mutex.h> 37 #include <sys/once.h> 38 #include <sys/systm.h> 39 40 #include <dev/i2c/i2cvar.h> 41 42 #include <arm/broadcom/bcm_amba.h> 43 #include <arm/broadcom/bcm2835reg.h> 44 #include <arm/broadcom/bcm2835_bscreg.h> 45 #include <arm/broadcom/bcm2835_gpio_subr.h> 46 47 #if defined(_KERNEL_OPT) 48 #include "opt_kernhist.h" 49 #endif 50 #include <sys/kernhist.h> 51 52 KERNHIST_DEFINE(bsciichist); 53 54 struct bsciic_softc { 55 device_t sc_dev; 56 bus_space_tag_t sc_iot; 57 bus_space_handle_t sc_ioh; 58 bus_size_t sc_ios; 59 struct i2c_controller sc_i2c; 60 kmutex_t sc_buslock; 61 void *sc_inth; 62 }; 63 64 static int bsciic_match(device_t, cfdata_t, void *); 65 static void bsciic_attach(device_t, device_t, void *); 66 67 void bsciic_dump_regs(struct bsciic_softc * const); 68 69 static int bsciic_acquire_bus(void *, int); 70 static void bsciic_release_bus(void *, int); 71 static int bsciic_exec(void *, i2c_op_t, i2c_addr_t, const void *, size_t, 72 void *, size_t, int); 73 74 CFATTACH_DECL_NEW(bsciic, sizeof(struct bsciic_softc), 75 bsciic_match, bsciic_attach, NULL, NULL); 76 77 static int 78 bsciic_init(void) 79 { 80 81 KERNHIST_INIT(bsciichist, 512); 82 83 return 0; 84 } 85 86 static int 87 bsciic_match(device_t parent, cfdata_t match, void *aux) 88 { 89 struct amba_attach_args * const aaa = aux; 90 91 if (strcmp(aaa->aaa_name, "bcmbsc") != 0) 92 return 0; 93 94 return 1; 95 } 96 97 static void 98 bsciic_attach(device_t parent, device_t self, void *aux) 99 { 100 struct bsciic_softc * const sc = device_private(self); 101 struct amba_attach_args * const aaa = aux; 102 prop_dictionary_t prop = device_properties(self); 103 struct i2cbus_attach_args iba; 104 u_int bscunit = ~0; 105 bool disable = false; 106 static ONCE_DECL(control); 107 108 switch (aaa->aaa_addr) { 109 case BCM2835_BSC0_BASE: 110 bscunit = 0; 111 break; 112 case BCM2835_BSC1_BASE: 113 bscunit = 1; 114 break; 115 } 116 117 prop_dictionary_get_bool(prop, "disable", &disable); 118 if (disable) { 119 aprint_naive(": disabled\n"); 120 aprint_normal(": disabled\n"); 121 return; 122 } 123 124 aprint_naive("\n"); 125 aprint_normal(": BSC%u\n", bscunit); 126 127 RUN_ONCE(&control, bsciic_init); 128 129 sc->sc_dev = self; 130 131 mutex_init(&sc->sc_buslock, MUTEX_DEFAULT, IPL_NONE); 132 133 sc->sc_iot = aaa->aaa_iot; 134 if (bus_space_map(aaa->aaa_iot, aaa->aaa_addr, aaa->aaa_size, 0, 135 &sc->sc_ioh) != 0) { 136 aprint_error_dev(sc->sc_dev, "unable to map device\n"); 137 return; 138 } 139 sc->sc_ios = aaa->aaa_size; 140 141 switch (aaa->aaa_addr) { 142 case BCM2835_BSC0_BASE: 143 /* SDA0 on GPIO0, SCL0 on GPIO1 */ 144 bcm2835gpio_function_select(0, BCM2835_GPIO_ALT0); 145 bcm2835gpio_function_select(1, BCM2835_GPIO_ALT0); 146 break; 147 case BCM2835_BSC1_BASE: 148 /* SDA1 on GPIO2, SCL1 on GPIO3 */ 149 bcm2835gpio_function_select(2, BCM2835_GPIO_ALT0); 150 bcm2835gpio_function_select(3, BCM2835_GPIO_ALT0); 151 break; 152 } 153 154 /* clear FIFO, disable controller */ 155 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, BSC_C_CLEAR_CLEAR); 156 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, BSC_S_CLKT | 157 BSC_S_ERR | BSC_S_DONE); 158 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DIV, 159 __SHIFTIN(250000000/100000, BSC_DIV_CDIV)); // XXX may not be this 160 161 sc->sc_i2c.ic_cookie = sc; 162 sc->sc_i2c.ic_acquire_bus = bsciic_acquire_bus; 163 sc->sc_i2c.ic_release_bus = bsciic_release_bus; 164 sc->sc_i2c.ic_exec = bsciic_exec; 165 166 memset(&iba, 0, sizeof(iba)); 167 168 iba.iba_tag = &sc->sc_i2c; 169 iba.iba_type = 0; 170 config_found_ia(self, "i2cbus", &iba, iicbus_print); 171 } 172 173 void 174 bsciic_dump_regs(struct bsciic_softc * const sc) 175 { 176 KERNHIST_FUNC(__func__); 177 KERNHIST_CALLED(bsciichist); 178 179 KERNHIST_LOG(bsciichist, "C %08x S %08x D %08x A %08x", 180 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_C), 181 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S), 182 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN), 183 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_A) 184 ); 185 } 186 187 static int 188 bsciic_acquire_bus(void *v, int flags) 189 { 190 struct bsciic_softc * const sc = v; 191 uint32_t s __diagused; 192 193 mutex_enter(&sc->sc_buslock); 194 195 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, BSC_S_CLKT | 196 BSC_S_ERR | BSC_S_DONE); 197 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, BSC_C_I2CEN | 198 BSC_C_CLEAR_CLEAR); 199 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 200 KASSERT((s & BSC_S_TA) == 0); 201 202 return 0; 203 } 204 205 static void 206 bsciic_release_bus(void *v, int flags) 207 { 208 struct bsciic_softc * const sc = v; 209 210 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, BSC_C_CLEAR_CLEAR); 211 212 mutex_exit(&sc->sc_buslock); 213 } 214 215 static int 216 bsciic_exec(void *v, i2c_op_t op, i2c_addr_t addr, const void *cmdbuf, 217 size_t cmdlen, void *databuf, size_t datalen, int flags) 218 { 219 KERNHIST_FUNC(__func__); KERNHIST_CALLED(bsciichist); 220 struct bsciic_softc * const sc = v; 221 uint32_t c, s, dlen, a; 222 uint32_t j; 223 uint8_t *buf; 224 size_t len; 225 size_t pos; 226 int error = 0; 227 const bool isread = I2C_OP_READ_P(op); 228 229 flags |= I2C_F_POLL; 230 231 #if 0 232 device_printf(sc->sc_dev, "exec: op %d, addr 0x%x, cmdbuf %p, " 233 "cmdlen %zu, databuf %p, datalen %zu, flags 0x%x\n", 234 op, addr, cmdbuf, cmdlen, databuf, datalen, flags); 235 #endif 236 237 a = __SHIFTIN(addr, BSC_A_ADDR); 238 c = BSC_C_I2CEN | BSC_C_CLEAR_CLEAR; 239 #if notyet 240 c |= BSC_C_INTR | BSC_C_INTT | BSC_C_INTD; 241 #endif 242 243 if (isread && cmdlen == 0) 244 goto only_read; 245 246 buf = __UNCONST(cmdbuf); 247 len = cmdlen; 248 249 if (isread) 250 dlen = cmdlen; 251 else 252 dlen = cmdlen + datalen; 253 dlen = __SHIFTIN(dlen, BSC_DLEN_DLEN); 254 255 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 256 if ((s & BSC_S_TA) != 0) 257 bsciic_dump_regs(sc); 258 KASSERT((s & BSC_S_TA) == 0); 259 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN, dlen); 260 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_A, a); 261 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, c | BSC_C_ST); 262 263 do { 264 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 265 } while ((s & BSC_S_TA) == 0); 266 267 flood_again: 268 KERNHIST_LOG(bsciichist, "flood top %p %zu", buf, len, 0, 0); 269 j = 10000000; 270 for (pos = 0; pos < len; ) { 271 if (--j == 0) 272 return -1; 273 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 274 KERNHIST_LOG(bsciichist, "w s %08x", s, 0, 0, 0); 275 if ((s & BSC_S_CLKT) != 0) { 276 error = EIO; 277 goto done; 278 } 279 if ((s & BSC_S_ERR) != 0) { 280 error = EIO; 281 goto done; 282 } 283 if ((s & BSC_S_DONE) != 0) 284 break; 285 if ((s & BSC_S_TXD) == 0) 286 continue; 287 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_FIFO, buf[pos]); 288 KERNHIST_LOG(bsciichist, "w %p %p %02x", buf, &buf[pos], 289 buf[pos], 0); 290 pos++; 291 } 292 KERNHIST_LOG(bsciichist, "flood bot %p %zu", buf, len, 0, 0); 293 294 if (buf == cmdbuf && !isread) { 295 buf = databuf; 296 len = datalen; 297 goto flood_again; 298 } 299 300 do { 301 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 302 } while ((s & BSC_S_TA) != 0); 303 304 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 305 s &= BSC_S_CLKT|BSC_S_ERR|BSC_S_DONE; 306 KASSERT((s & BSC_S_DONE) != 0); 307 if (s != 0) 308 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, s); 309 310 if (error == 0 && (s & (BSC_S_CLKT|BSC_S_ERR)) != 0) 311 error = EIO; 312 313 if (!isread) 314 goto done; 315 316 only_read: 317 c |= BSC_C_READ; 318 319 buf = databuf; 320 len = datalen; 321 dlen = datalen; 322 323 dlen = __SHIFTIN(dlen, BSC_DLEN_DLEN); 324 KASSERT(dlen >= 1); 325 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN, dlen); 326 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_A, a); 327 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, c | BSC_C_ST); 328 329 do { 330 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 331 } while ((s & BSC_S_TA) == 0); 332 333 KERNHIST_LOG(bsciichist, "drain top %p %zu", buf, len, 0, 0); 334 j = 10000000; 335 for (pos = 0; pos < len; ) { 336 if (--j == 0) 337 return -1; 338 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 339 KERNHIST_LOG(bsciichist, "r s %08x", s, 0, 0, 0); 340 if ((s & BSC_S_CLKT) != 0) { 341 error = EIO; 342 goto done; 343 } 344 if ((s & BSC_S_ERR) != 0) { 345 error = EIO; 346 goto done; 347 } 348 if ((s & BSC_S_DONE) != 0) 349 break; 350 if ((s & BSC_S_RXD) == 0) 351 continue; 352 j = 10000000; 353 buf[pos] = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_FIFO); 354 KERNHIST_LOG(bsciichist, "r %p %p %02x", buf, &buf[pos], 355 buf[pos], 0); 356 pos++; 357 } 358 KERNHIST_LOG(bsciichist, "drain bot %p %zu", buf, len, 0, 0); 359 360 do { 361 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 362 } while ((s & BSC_S_TA) != 0); 363 364 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 365 s &= BSC_S_CLKT|BSC_S_ERR|BSC_S_DONE; 366 KASSERT((s & BSC_S_DONE) != 0); 367 if (s != 0) 368 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, s); 369 370 done: 371 bsciic_dump_regs(sc); 372 373 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN, 0); 374 375 do { 376 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 377 } while ((s & BSC_S_TA) != 0); 378 379 bsciic_dump_regs(sc); 380 381 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 382 s &= BSC_S_CLKT|BSC_S_ERR|BSC_S_DONE; 383 if (s != 0) 384 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, s); 385 386 bsciic_dump_regs(sc); 387 388 if (error == 0 && (s & (BSC_S_CLKT|BSC_S_ERR)) != 0) 389 error = EIO; 390 391 return error; 392 } 393
Indexes created Tue Sep 30 11:09:46 GMT 2025