1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 1998, 2001 Nicolas Souchu 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 AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 /* 31 * Autoconfiguration and support routines for the Philips serial I2C bus 32 */ 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/bus.h> 38 #include <sys/lock.h> 39 #include <sys/malloc.h> 40 #include <sys/module.h> 41 #include <sys/mutex.h> 42 #include <sys/rman.h> 43 #include <sys/sbuf.h> 44 #include <sys/sysctl.h> 45 46 #include <dev/iicbus/iiconf.h> 47 #include <dev/iicbus/iicbus.h> 48 49 #include "iicbus_if.h" 50 51 /* See comments below for why auto-scanning is a bad idea. */ 52 #define SCAN_IICBUS 0 53 54 SYSCTL_NODE(_hw, OID_AUTO, i2c, CTLFLAG_RW, 0, "i2c controls"); 55 56 static int 57 iicbus_probe(device_t dev) 58 { 59 60 device_set_desc(dev, "Philips I2C bus"); 61 62 /* Allow other subclasses to override this driver. */ 63 return (BUS_PROBE_GENERIC); 64 } 65 66 #if SCAN_IICBUS 67 static int 68 iic_probe_device(device_t dev, u_char addr) 69 { 70 int count; 71 char byte; 72 73 if ((addr & 1) == 0) { 74 /* is device writable? */ 75 if (!iicbus_start(dev, (u_char)addr, 0)) { 76 iicbus_stop(dev); 77 return (1); 78 } 79 } else { 80 /* is device readable? */ 81 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count)) 82 return (1); 83 } 84 85 return (0); 86 } 87 #endif 88 89 /* 90 * We add all the devices which we know about. 91 * The generic attach routine will attach them if they are alive. 92 */ 93 int 94 iicbus_attach_common(device_t dev, u_int bus_freq) 95 { 96 #if SCAN_IICBUS 97 unsigned char addr; 98 #endif 99 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 100 int strict; 101 102 sc->dev = dev; 103 mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF); 104 iicbus_init_frequency(dev, bus_freq); 105 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 106 if (resource_int_value(device_get_name(dev), 107 device_get_unit(dev), "strict", &strict) == 0) 108 sc->strict = strict; 109 else 110 sc->strict = 1; 111 112 /* device probing is meaningless since the bus is supposed to be 113 * hot-plug. Moreover, some I2C chips do not appreciate random 114 * accesses like stop after start to fast, reads for less than 115 * x bytes... 116 */ 117 #if SCAN_IICBUS 118 printf("Probing for devices on iicbus%d:", device_get_unit(dev)); 119 120 /* probe any devices */ 121 for (addr = 16; addr < 240; addr++) { 122 if (iic_probe_device(dev, (u_char)addr)) { 123 printf(" <%x>", addr); 124 } 125 } 126 printf("\n"); 127 #endif 128 bus_identify_children(dev); 129 bus_enumerate_hinted_children(dev); 130 bus_attach_children(dev); 131 return (0); 132 } 133 134 static int 135 iicbus_attach(device_t dev) 136 { 137 138 return (iicbus_attach_common(dev, 0)); 139 } 140 141 int 142 iicbus_detach(device_t dev) 143 { 144 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 145 int err; 146 147 if ((err = device_delete_children(dev)) != 0) 148 return (err); 149 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 150 mtx_destroy(&sc->lock); 151 return (0); 152 } 153 154 static int 155 iicbus_print_child(device_t dev, device_t child) 156 { 157 struct iicbus_ivar *devi = IICBUS_IVAR(child); 158 int retval = 0; 159 160 retval += bus_print_child_header(dev, child); 161 if (devi->addr != 0) 162 retval += printf(" at addr %#x", devi->addr); 163 resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd"); 164 retval += bus_print_child_footer(dev, child); 165 166 return (retval); 167 } 168 169 void 170 iicbus_probe_nomatch(device_t bus, device_t child) 171 { 172 struct iicbus_ivar *devi = IICBUS_IVAR(child); 173 174 device_printf(bus, "<unknown card> at addr %#x\n", devi->addr); 175 } 176 177 int 178 iicbus_child_location(device_t bus, device_t child, struct sbuf *sb) 179 { 180 struct iicbus_ivar *devi = IICBUS_IVAR(child); 181 182 sbuf_printf(sb, "addr=%#x", devi->addr); 183 return (0); 184 } 185 186 int 187 iicbus_child_pnpinfo(device_t bus, device_t child, struct sbuf *sb) 188 { 189 return (0); 190 } 191 192 int 193 iicbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result) 194 { 195 struct iicbus_ivar *devi = IICBUS_IVAR(child); 196 197 switch (which) { 198 default: 199 return (EINVAL); 200 case IICBUS_IVAR_ADDR: 201 *result = devi->addr; 202 break; 203 } 204 return (0); 205 } 206 207 int 208 iicbus_write_ivar(device_t bus, device_t child, int which, uintptr_t value) 209 { 210 struct iicbus_ivar *devi = IICBUS_IVAR(child); 211 212 switch (which) { 213 default: 214 return (EINVAL); 215 case IICBUS_IVAR_ADDR: 216 if (devi->addr != 0) 217 return (EINVAL); 218 devi->addr = value; 219 } 220 return (0); 221 } 222 223 device_t 224 iicbus_add_child_common(device_t dev, u_int order, const char *name, int unit, 225 size_t ivars_size) 226 { 227 device_t child; 228 struct iicbus_ivar *devi; 229 230 child = device_add_child_ordered(dev, order, name, unit); 231 if (child == NULL) 232 return (child); 233 devi = malloc(ivars_size, M_DEVBUF, M_NOWAIT | M_ZERO); 234 if (devi == NULL) { 235 device_delete_child(dev, child); 236 return (0); 237 } 238 resource_list_init(&devi->rl); 239 device_set_ivars(child, devi); 240 return (child); 241 } 242 243 static device_t 244 iicbus_add_child(device_t dev, u_int order, const char *name, int unit) 245 { 246 247 return (iicbus_add_child_common( 248 dev, order, name, unit, sizeof(struct iicbus_ivar))); 249 } 250 251 static void 252 iicbus_child_deleted(device_t dev, device_t child) 253 { 254 struct iicbus_ivar *devi; 255 256 devi = device_get_ivars(child); 257 if (devi == NULL) 258 return; 259 resource_list_free(&devi->rl); 260 free(devi, M_DEVBUF); 261 } 262 263 static void 264 iicbus_hinted_child(device_t bus, const char *dname, int dunit) 265 { 266 device_t child; 267 int irq; 268 struct iicbus_ivar *devi; 269 270 child = BUS_ADD_CHILD(bus, 0, dname, dunit); 271 devi = IICBUS_IVAR(child); 272 resource_int_value(dname, dunit, "addr", &devi->addr); 273 if (resource_int_value(dname, dunit, "irq", &irq) == 0) { 274 if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0) 275 device_printf(bus, 276 "warning: bus_set_resource() failed\n"); 277 } 278 } 279 280 static struct resource_list * 281 iicbus_get_resource_list(device_t bus __unused, device_t child) 282 { 283 struct iicbus_ivar *devi; 284 285 devi = IICBUS_IVAR(child); 286 return (&devi->rl); 287 } 288 289 int 290 iicbus_generic_intr(device_t dev, int event, char *buf) 291 { 292 293 return (0); 294 } 295 296 int 297 iicbus_null_callback(device_t dev, int index, caddr_t data) 298 { 299 300 return (0); 301 } 302 303 int 304 iicbus_null_repeated_start(device_t dev, u_char addr) 305 { 306 307 return (IIC_ENOTSUPP); 308 } 309 310 void 311 iicbus_init_frequency(device_t dev, u_int bus_freq) 312 { 313 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 314 315 /* 316 * If a bus frequency value was passed in, use it. Otherwise initialize 317 * it first to the standard i2c 100KHz frequency, then override that 318 * from a hint if one exists. 319 */ 320 if (bus_freq > 0) 321 sc->bus_freq = bus_freq; 322 else { 323 sc->bus_freq = 100000; 324 resource_int_value(device_get_name(dev), device_get_unit(dev), 325 "frequency", (int *)&sc->bus_freq); 326 } 327 /* 328 * Set up the sysctl that allows the bus frequency to be changed. 329 * It is flagged as a tunable so that the user can set the value in 330 * loader(8), and that will override any other setting from any source. 331 * The sysctl tunable/value is the one most directly controlled by the 332 * user and thus the one that always takes precedence. 333 */ 334 SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev), 335 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 336 OID_AUTO, "frequency", CTLFLAG_RWTUN, &sc->bus_freq, 337 sc->bus_freq, "Bus frequency in Hz"); 338 } 339 340 static u_int 341 iicbus_get_frequency(device_t dev, u_char speed) 342 { 343 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 344 345 /* 346 * If the frequency has not been configured for the bus, or the request 347 * is specifically for SLOW speed, use the standard 100KHz rate, else 348 * use the configured bus speed. 349 */ 350 if (sc->bus_freq == 0 || speed == IIC_SLOW) 351 return (100000); 352 return (sc->bus_freq); 353 } 354 355 static device_method_t iicbus_methods[] = { 356 /* device interface */ 357 DEVMETHOD(device_probe, iicbus_probe), 358 DEVMETHOD(device_attach, iicbus_attach), 359 DEVMETHOD(device_detach, iicbus_detach), 360 DEVMETHOD(device_suspend, bus_generic_suspend), 361 DEVMETHOD(device_resume, bus_generic_resume), 362 363 /* bus interface */ 364 DEVMETHOD(bus_setup_intr, bus_generic_setup_intr), 365 DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr), 366 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 367 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 368 DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource), 369 DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource), 370 DEVMETHOD(bus_get_resource, bus_generic_rl_get_resource), 371 DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource), 372 DEVMETHOD(bus_set_resource, bus_generic_rl_set_resource), 373 DEVMETHOD(bus_get_resource_list, iicbus_get_resource_list), 374 DEVMETHOD(bus_add_child, iicbus_add_child), 375 DEVMETHOD(bus_child_deleted, iicbus_child_deleted), 376 DEVMETHOD(bus_print_child, iicbus_print_child), 377 DEVMETHOD(bus_probe_nomatch, iicbus_probe_nomatch), 378 DEVMETHOD(bus_read_ivar, iicbus_read_ivar), 379 DEVMETHOD(bus_write_ivar, iicbus_write_ivar), 380 DEVMETHOD(bus_child_pnpinfo, iicbus_child_pnpinfo), 381 DEVMETHOD(bus_child_location, iicbus_child_location), 382 DEVMETHOD(bus_hinted_child, iicbus_hinted_child), 383 384 /* iicbus interface */ 385 DEVMETHOD(iicbus_transfer, iicbus_transfer), 386 DEVMETHOD(iicbus_get_frequency, iicbus_get_frequency), 387 388 DEVMETHOD_END 389 }; 390 391 driver_t iicbus_driver = { 392 "iicbus", 393 iicbus_methods, 394 sizeof(struct iicbus_softc), 395 }; 396 397 MODULE_VERSION(iicbus, IICBUS_MODVER); 398 DRIVER_MODULE(iicbus, iichb, iicbus_driver, 0, 0); 399