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