1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 31 32 /* 33 * Autoconfiguration and support routines for the Philips serial I2C bus 34 */ 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/kernel.h> 39 #include <sys/lock.h> 40 #include <sys/malloc.h> 41 #include <sys/module.h> 42 #include <sys/mutex.h> 43 #include <sys/rman.h> 44 #include <sys/sysctl.h> 45 #include <sys/bus.h> 46 47 #include <dev/iicbus/iiconf.h> 48 #include <dev/iicbus/iicbus.h> 49 50 #include "iicbus_if.h" 51 52 /* See comments below for why auto-scanning is a bad idea. */ 53 #define SCAN_IICBUS 0 54 55 SYSCTL_NODE(_hw, OID_AUTO, i2c, CTLFLAG_RW, 0, "i2c controls"); 56 57 static int 58 iicbus_probe(device_t dev) 59 { 60 61 device_set_desc(dev, "Philips I2C bus"); 62 63 /* Allow other subclasses to override this driver. */ 64 return (BUS_PROBE_GENERIC); 65 } 66 67 #if SCAN_IICBUS 68 static int 69 iic_probe_device(device_t dev, u_char addr) 70 { 71 int count; 72 char byte; 73 74 if ((addr & 1) == 0) { 75 /* is device writable? */ 76 if (!iicbus_start(dev, (u_char)addr, 0)) { 77 iicbus_stop(dev); 78 return (1); 79 } 80 } else { 81 /* is device readable? */ 82 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count)) 83 return (1); 84 } 85 86 return (0); 87 } 88 #endif 89 90 /* 91 * We add all the devices which we know about. 92 * The generic attach routine will attach them if they are alive. 93 */ 94 int 95 iicbus_attach_common(device_t dev, u_int bus_freq) 96 { 97 #if SCAN_IICBUS 98 unsigned char addr; 99 #endif 100 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 101 int strict; 102 103 sc->dev = dev; 104 mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF); 105 iicbus_init_frequency(dev, bus_freq); 106 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 107 if (resource_int_value(device_get_name(dev), 108 device_get_unit(dev), "strict", &strict) == 0) 109 sc->strict = strict; 110 else 111 sc->strict = 1; 112 113 /* device probing is meaningless since the bus is supposed to be 114 * hot-plug. Moreover, some I2C chips do not appreciate random 115 * accesses like stop after start to fast, reads for less than 116 * x bytes... 117 */ 118 #if SCAN_IICBUS 119 printf("Probing for devices on iicbus%d:", device_get_unit(dev)); 120 121 /* probe any devices */ 122 for (addr = 16; addr < 240; addr++) { 123 if (iic_probe_device(dev, (u_char)addr)) { 124 printf(" <%x>", addr); 125 } 126 } 127 printf("\n"); 128 #endif 129 bus_generic_probe(dev); 130 bus_enumerate_hinted_children(dev); 131 bus_generic_attach(dev); 132 return (0); 133 } 134 135 static int 136 iicbus_attach(device_t dev) 137 { 138 139 return (iicbus_attach_common(dev, 0)); 140 } 141 142 int 143 iicbus_detach(device_t dev) 144 { 145 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 146 int err; 147 148 if ((err = device_delete_children(dev)) != 0) 149 return (err); 150 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 151 mtx_destroy(&sc->lock); 152 return (0); 153 } 154 155 static int 156 iicbus_print_child(device_t dev, device_t child) 157 { 158 struct iicbus_ivar *devi = IICBUS_IVAR(child); 159 int retval = 0; 160 161 retval += bus_print_child_header(dev, child); 162 if (devi->addr != 0) 163 retval += printf(" at addr %#x", devi->addr); 164 resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%jd"); 165 retval += bus_print_child_footer(dev, child); 166 167 return (retval); 168 } 169 170 void 171 iicbus_probe_nomatch(device_t bus, device_t child) 172 { 173 struct iicbus_ivar *devi = IICBUS_IVAR(child); 174 175 device_printf(bus, "<unknown card> at addr %#x\n", devi->addr); 176 } 177 178 int 179 iicbus_child_location_str(device_t bus, device_t child, char *buf, 180 size_t buflen) 181 { 182 struct iicbus_ivar *devi = IICBUS_IVAR(child); 183 184 snprintf(buf, buflen, "addr=%#x", devi->addr); 185 return (0); 186 } 187 188 int 189 iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf, 190 size_t buflen) 191 { 192 *buf = '\0'; 193 return (0); 194 } 195 196 int 197 iicbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result) 198 { 199 struct iicbus_ivar *devi = IICBUS_IVAR(child); 200 201 switch (which) { 202 default: 203 return (EINVAL); 204 case IICBUS_IVAR_ADDR: 205 *result = devi->addr; 206 break; 207 } 208 return (0); 209 } 210 211 int 212 iicbus_write_ivar(device_t bus, device_t child, int which, uintptr_t value) 213 { 214 struct iicbus_ivar *devi = IICBUS_IVAR(child); 215 216 switch (which) { 217 default: 218 return (EINVAL); 219 case IICBUS_IVAR_ADDR: 220 if (devi->addr != 0) 221 return (EINVAL); 222 devi->addr = value; 223 } 224 return (0); 225 } 226 227 device_t 228 iicbus_add_child_common(device_t dev, u_int order, const char *name, int unit, 229 size_t ivars_size) 230 { 231 device_t child; 232 struct iicbus_ivar *devi; 233 234 child = device_add_child_ordered(dev, order, name, unit); 235 if (child == NULL) 236 return (child); 237 devi = malloc(ivars_size, M_DEVBUF, M_NOWAIT | M_ZERO); 238 if (devi == NULL) { 239 device_delete_child(dev, child); 240 return (0); 241 } 242 resource_list_init(&devi->rl); 243 device_set_ivars(child, devi); 244 return (child); 245 } 246 247 static device_t 248 iicbus_add_child(device_t dev, u_int order, const char *name, int unit) 249 { 250 251 return (iicbus_add_child_common( 252 dev, order, name, unit, sizeof(struct iicbus_ivar))); 253 } 254 255 static void 256 iicbus_hinted_child(device_t bus, const char *dname, int dunit) 257 { 258 device_t child; 259 int irq; 260 struct iicbus_ivar *devi; 261 262 child = BUS_ADD_CHILD(bus, 0, dname, dunit); 263 devi = IICBUS_IVAR(child); 264 resource_int_value(dname, dunit, "addr", &devi->addr); 265 if (resource_int_value(dname, dunit, "irq", &irq) == 0) { 266 if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0) 267 device_printf(bus, 268 "warning: bus_set_resource() failed\n"); 269 } 270 } 271 272 static struct resource_list * 273 iicbus_get_resource_list(device_t bus __unused, device_t child) 274 { 275 struct iicbus_ivar *devi; 276 277 devi = IICBUS_IVAR(child); 278 return (&devi->rl); 279 } 280 281 int 282 iicbus_generic_intr(device_t dev, int event, char *buf) 283 { 284 285 return (0); 286 } 287 288 int 289 iicbus_null_callback(device_t dev, int index, caddr_t data) 290 { 291 292 return (0); 293 } 294 295 int 296 iicbus_null_repeated_start(device_t dev, u_char addr) 297 { 298 299 return (IIC_ENOTSUPP); 300 } 301 302 void 303 iicbus_init_frequency(device_t dev, u_int bus_freq) 304 { 305 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 306 307 /* 308 * If a bus frequency value was passed in, use it. Otherwise initialize 309 * it first to the standard i2c 100KHz frequency, then override that 310 * from a hint if one exists. 311 */ 312 if (bus_freq > 0) 313 sc->bus_freq = bus_freq; 314 else { 315 sc->bus_freq = 100000; 316 resource_int_value(device_get_name(dev), device_get_unit(dev), 317 "frequency", (int *)&sc->bus_freq); 318 } 319 /* 320 * Set up the sysctl that allows the bus frequency to be changed. 321 * It is flagged as a tunable so that the user can set the value in 322 * loader(8), and that will override any other setting from any source. 323 * The sysctl tunable/value is the one most directly controlled by the 324 * user and thus the one that always takes precedence. 325 */ 326 SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev), 327 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 328 OID_AUTO, "frequency", CTLFLAG_RW | CTLFLAG_TUN, &sc->bus_freq, 329 sc->bus_freq, "Bus frequency in Hz"); 330 } 331 332 static u_int 333 iicbus_get_frequency(device_t dev, u_char speed) 334 { 335 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 336 337 /* 338 * If the frequency has not been configured for the bus, or the request 339 * is specifically for SLOW speed, use the standard 100KHz rate, else 340 * use the configured bus speed. 341 */ 342 if (sc->bus_freq == 0 || speed == IIC_SLOW) 343 return (100000); 344 return (sc->bus_freq); 345 } 346 347 static device_method_t iicbus_methods[] = { 348 /* device interface */ 349 DEVMETHOD(device_probe, iicbus_probe), 350 DEVMETHOD(device_attach, iicbus_attach), 351 DEVMETHOD(device_detach, iicbus_detach), 352 DEVMETHOD(device_suspend, bus_generic_suspend), 353 DEVMETHOD(device_resume, bus_generic_resume), 354 355 /* bus interface */ 356 DEVMETHOD(bus_setup_intr, bus_generic_setup_intr), 357 DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr), 358 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 359 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 360 DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource), 361 DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource), 362 DEVMETHOD(bus_get_resource, bus_generic_rl_get_resource), 363 DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource), 364 DEVMETHOD(bus_set_resource, bus_generic_rl_set_resource), 365 DEVMETHOD(bus_get_resource_list, iicbus_get_resource_list), 366 DEVMETHOD(bus_add_child, iicbus_add_child), 367 DEVMETHOD(bus_print_child, iicbus_print_child), 368 DEVMETHOD(bus_probe_nomatch, iicbus_probe_nomatch), 369 DEVMETHOD(bus_read_ivar, iicbus_read_ivar), 370 DEVMETHOD(bus_write_ivar, iicbus_write_ivar), 371 DEVMETHOD(bus_child_pnpinfo_str, iicbus_child_pnpinfo_str), 372 DEVMETHOD(bus_child_location_str, iicbus_child_location_str), 373 DEVMETHOD(bus_hinted_child, iicbus_hinted_child), 374 375 /* iicbus interface */ 376 DEVMETHOD(iicbus_transfer, iicbus_transfer), 377 DEVMETHOD(iicbus_get_frequency, iicbus_get_frequency), 378 379 DEVMETHOD_END 380 }; 381 382 driver_t iicbus_driver = { 383 "iicbus", 384 iicbus_methods, 385 sizeof(struct iicbus_softc), 386 }; 387 388 devclass_t iicbus_devclass; 389 390 MODULE_VERSION(iicbus, IICBUS_MODVER); 391 DRIVER_MODULE(iicbus, iichb, iicbus_driver, iicbus_devclass, 0, 0); 392