bcm2835_bsc.c revision 1.5
1 /* $NetBSD: bcm2835_bsc.c,v 1.5 2015/01/24 00:27:31 jakllsch 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 1.5 2015/01/24 00:27:31 jakllsch 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 struct i2cbus_attach_args iba; 103 u_int bscunit = ~0; 104 static ONCE_DECL(control); 105 106 switch (aaa->aaa_addr) { 107 case BCM2835_BSC0_BASE: 108 bscunit = 0; 109 break; 110 case BCM2835_BSC1_BASE: 111 bscunit = 1; 112 break; 113 } 114 115 aprint_naive("\n"); 116 aprint_normal(": BSC%u\n", bscunit); 117 118 RUN_ONCE(&control, bsciic_init); 119 120 sc->sc_dev = self; 121 122 mutex_init(&sc->sc_buslock, MUTEX_DEFAULT, IPL_NONE); 123 124 sc->sc_iot = aaa->aaa_iot; 125 if (bus_space_map(aaa->aaa_iot, aaa->aaa_addr, aaa->aaa_size, 0, 126 &sc->sc_ioh) != 0) { 127 aprint_error_dev(sc->sc_dev, "unable to map device\n"); 128 return; 129 } 130 sc->sc_ios = aaa->aaa_size; 131 132 switch (aaa->aaa_addr) { 133 case BCM2835_BSC0_BASE: 134 /* SDA0 on GPIO0, SCL0 on GPIO1 */ 135 bcm2835gpio_function_select(0, BCM2835_GPIO_ALT0); 136 bcm2835gpio_function_select(1, BCM2835_GPIO_ALT0); 137 break; 138 case BCM2835_BSC1_BASE: 139 /* SDA1 on GPIO2, SCL1 on GPIO3 */ 140 bcm2835gpio_function_select(2, BCM2835_GPIO_ALT0); 141 bcm2835gpio_function_select(3, BCM2835_GPIO_ALT0); 142 break; 143 } 144 145 /* clear FIFO, disable controller */ 146 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, BSC_C_CLEAR_CLEAR); 147 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, BSC_S_CLKT | 148 BSC_S_ERR | BSC_S_DONE); 149 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DIV, 150 __SHIFTIN(250000000/100000, BSC_DIV_CDIV)); // XXX may not be this 151 152 sc->sc_i2c.ic_cookie = sc; 153 sc->sc_i2c.ic_acquire_bus = bsciic_acquire_bus; 154 sc->sc_i2c.ic_release_bus = bsciic_release_bus; 155 sc->sc_i2c.ic_exec = bsciic_exec; 156 157 memset(&iba, 0, sizeof(iba)); 158 159 iba.iba_tag = &sc->sc_i2c; 160 iba.iba_type = 0; 161 config_found_ia(self, "i2cbus", &iba, iicbus_print); 162 } 163 164 void 165 bsciic_dump_regs(struct bsciic_softc * const sc) 166 { 167 KERNHIST_FUNC(__func__); 168 KERNHIST_CALLED(bsciichist); 169 170 KERNHIST_LOG(bsciichist, "C %08x S %08x D %08x A %08x", 171 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_C), 172 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S), 173 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN), 174 bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_A) 175 ); 176 } 177 178 static int 179 bsciic_acquire_bus(void *v, int flags) 180 { 181 struct bsciic_softc * const sc = v; 182 uint32_t s __diagused; 183 184 mutex_enter(&sc->sc_buslock); 185 186 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, BSC_S_CLKT | 187 BSC_S_ERR | BSC_S_DONE); 188 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, BSC_C_I2CEN | 189 BSC_C_CLEAR_CLEAR); 190 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 191 KASSERT((s & BSC_S_TA) == 0); 192 193 return 0; 194 } 195 196 static void 197 bsciic_release_bus(void *v, int flags) 198 { 199 struct bsciic_softc * const sc = v; 200 201 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, BSC_C_CLEAR_CLEAR); 202 203 mutex_exit(&sc->sc_buslock); 204 } 205 206 static int 207 bsciic_exec(void *v, i2c_op_t op, i2c_addr_t addr, const void *cmdbuf, 208 size_t cmdlen, void *databuf, size_t datalen, int flags) 209 { 210 KERNHIST_FUNC(__func__); KERNHIST_CALLED(bsciichist); 211 struct bsciic_softc * const sc = v; 212 uint32_t c, s, dlen, a; 213 uint32_t j; 214 uint8_t *buf; 215 size_t len; 216 size_t pos; 217 int error = 0; 218 const bool isread = I2C_OP_READ_P(op); 219 220 flags |= I2C_F_POLL; 221 222 #if 0 223 device_printf(sc->sc_dev, "exec: op %d, addr 0x%x, cmdbuf %p, " 224 "cmdlen %zu, databuf %p, datalen %zu, flags 0x%x\n", 225 op, addr, cmdbuf, cmdlen, databuf, datalen, flags); 226 #endif 227 228 a = __SHIFTIN(addr, BSC_A_ADDR); 229 c = BSC_C_I2CEN | BSC_C_CLEAR_CLEAR; 230 #if notyet 231 c |= BSC_C_INTR | BSC_C_INTT | BSC_C_INTD; 232 #endif 233 234 if (isread && cmdlen == 0) 235 goto only_read; 236 237 buf = __UNCONST(cmdbuf); 238 len = cmdlen; 239 240 if (isread) 241 dlen = cmdlen; 242 else 243 dlen = cmdlen + datalen; 244 dlen = __SHIFTIN(dlen, BSC_DLEN_DLEN); 245 246 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 247 if ((s & BSC_S_TA) != 0) 248 bsciic_dump_regs(sc); 249 KASSERT((s & BSC_S_TA) == 0); 250 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN, dlen); 251 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_A, a); 252 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, c | BSC_C_ST); 253 254 do { 255 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 256 } while ((s & BSC_S_TA) == 0); 257 258 flood_again: 259 KERNHIST_LOG(bsciichist, "flood top %p %zu", buf, len, 0, 0); 260 j = 10000000; 261 for (pos = 0; pos < len; ) { 262 if (--j == 0) 263 return -1; 264 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 265 KERNHIST_LOG(bsciichist, "w s %08x", s, 0, 0, 0); 266 if ((s & BSC_S_CLKT) != 0) { 267 error = EIO; 268 goto done; 269 } 270 if ((s & BSC_S_ERR) != 0) { 271 error = EIO; 272 goto done; 273 } 274 if ((s & BSC_S_DONE) != 0) 275 break; 276 if ((s & BSC_S_TXD) == 0) 277 continue; 278 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_FIFO, buf[pos]); 279 KERNHIST_LOG(bsciichist, "w %p %p %02x", buf, &buf[pos], 280 buf[pos], 0); 281 pos++; 282 } 283 KERNHIST_LOG(bsciichist, "flood bot %p %zu", buf, len, 0, 0); 284 285 if (buf == cmdbuf && !isread) { 286 buf = databuf; 287 len = datalen; 288 goto flood_again; 289 } 290 291 do { 292 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 293 } while ((s & BSC_S_TA) != 0); 294 295 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 296 s &= BSC_S_CLKT|BSC_S_ERR|BSC_S_DONE; 297 KASSERT((s & BSC_S_DONE) != 0); 298 if (s != 0) 299 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, s); 300 301 if (error == 0 && (s & (BSC_S_CLKT|BSC_S_ERR)) != 0) 302 error = EIO; 303 304 if (!isread) 305 goto done; 306 307 only_read: 308 c |= BSC_C_READ; 309 310 buf = databuf; 311 len = datalen; 312 dlen = datalen; 313 314 dlen = __SHIFTIN(dlen, BSC_DLEN_DLEN); 315 KASSERT(dlen >= 1); 316 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN, dlen); 317 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_A, a); 318 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_C, c | BSC_C_ST); 319 320 do { 321 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 322 } while ((s & BSC_S_TA) == 0); 323 324 KERNHIST_LOG(bsciichist, "drain top %p %zu", buf, len, 0, 0); 325 j = 10000000; 326 for (pos = 0; pos < len; ) { 327 if (--j == 0) 328 return -1; 329 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 330 KERNHIST_LOG(bsciichist, "r s %08x", s, 0, 0, 0); 331 if ((s & BSC_S_CLKT) != 0) { 332 error = EIO; 333 goto done; 334 } 335 if ((s & BSC_S_ERR) != 0) { 336 error = EIO; 337 goto done; 338 } 339 if ((s & BSC_S_DONE) != 0) 340 break; 341 if ((s & BSC_S_RXD) == 0) 342 continue; 343 j = 10000000; 344 buf[pos] = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_FIFO); 345 KERNHIST_LOG(bsciichist, "r %p %p %02x", buf, &buf[pos], 346 buf[pos], 0); 347 pos++; 348 } 349 KERNHIST_LOG(bsciichist, "drain bot %p %zu", buf, len, 0, 0); 350 351 do { 352 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 353 } while ((s & BSC_S_TA) != 0); 354 355 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 356 s &= BSC_S_CLKT|BSC_S_ERR|BSC_S_DONE; 357 KASSERT((s & BSC_S_DONE) != 0); 358 if (s != 0) 359 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, s); 360 361 done: 362 bsciic_dump_regs(sc); 363 364 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_DLEN, 0); 365 366 do { 367 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 368 } while ((s & BSC_S_TA) != 0); 369 370 bsciic_dump_regs(sc); 371 372 s = bus_space_read_4(sc->sc_iot, sc->sc_ioh, BSC_S); 373 s &= BSC_S_CLKT|BSC_S_ERR|BSC_S_DONE; 374 if (s != 0) 375 bus_space_write_4(sc->sc_iot, sc->sc_ioh, BSC_S, s); 376 377 bsciic_dump_regs(sc); 378 379 if (error == 0 && (s & (BSC_S_CLKT|BSC_S_ERR)) != 0) 380 error = EIO; 381 382 return error; 383 } 384
Indexes created Tue Sep 30 11:09:46 GMT 2025