iicbus.c revision 289656
1/*- 2 * Copyright (c) 1998, 2001 Nicolas Souchu 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/dev/iicbus/iicbus.c 289656 2015-10-20 19:47:08Z dumbbell $"); 29 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/lock.h> 38#include <sys/malloc.h> 39#include <sys/module.h> 40#include <sys/mutex.h> 41#include <sys/rman.h> 42#include <sys/sysctl.h> 43#include <sys/bus.h> 44 45#include <dev/iicbus/iiconf.h> 46#include <dev/iicbus/iicbus.h> 47 48#include "iicbus_if.h" 49 50/* See comments below for why auto-scanning is a bad idea. */ 51#define SCAN_IICBUS 0 52 53static int 54iicbus_probe(device_t dev) 55{ 56 57 device_set_desc(dev, "Philips I2C bus"); 58 59 /* Allow other subclasses to override this driver. */ 60 return (BUS_PROBE_GENERIC); 61} 62 63#if SCAN_IICBUS 64static int 65iic_probe_device(device_t dev, u_char addr) 66{ 67 int count; 68 char byte; 69 70 if ((addr & 1) == 0) { 71 /* is device writable? */ 72 if (!iicbus_start(dev, (u_char)addr, 0)) { 73 iicbus_stop(dev); 74 return (1); 75 } 76 } else { 77 /* is device readable? */ 78 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count)) 79 return (1); 80 } 81 82 return (0); 83} 84#endif 85 86/* 87 * We add all the devices which we know about. 88 * The generic attach routine will attach them if they are alive. 89 */ 90static int 91iicbus_attach(device_t dev) 92{ 93#if SCAN_IICBUS 94 unsigned char addr; 95#endif 96 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 97 int strict; 98 99 sc->dev = dev; 100 mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF); 101 iicbus_init_frequency(dev, 0); 102 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 103 if (resource_int_value(device_get_name(dev), 104 device_get_unit(dev), "strict", &strict) == 0) 105 sc->strict = strict; 106 else 107 sc->strict = 1; 108 109 /* device probing is meaningless since the bus is supposed to be 110 * hot-plug. Moreover, some I2C chips do not appreciate random 111 * accesses like stop after start to fast, reads for less than 112 * x bytes... 113 */ 114#if SCAN_IICBUS 115 printf("Probing for devices on iicbus%d:", device_get_unit(dev)); 116 117 /* probe any devices */ 118 for (addr = 16; addr < 240; addr++) { 119 if (iic_probe_device(dev, (u_char)addr)) { 120 printf(" <%x>", addr); 121 } 122 } 123 printf("\n"); 124#endif 125 bus_generic_probe(dev); 126 bus_enumerate_hinted_children(dev); 127 bus_generic_attach(dev); 128 return (0); 129} 130 131static int 132iicbus_detach(device_t dev) 133{ 134 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 135 136 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 137 bus_generic_detach(dev); 138 mtx_destroy(&sc->lock); 139 return (0); 140} 141 142static int 143iicbus_print_child(device_t dev, device_t child) 144{ 145 struct iicbus_ivar *devi = IICBUS_IVAR(child); 146 int retval = 0; 147 148 retval += bus_print_child_header(dev, child); 149 if (devi->addr != 0) 150 retval += printf(" at addr %#x", devi->addr); 151 resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%ld"); 152 retval += bus_print_child_footer(dev, child); 153 154 return (retval); 155} 156 157static void 158iicbus_probe_nomatch(device_t bus, device_t child) 159{ 160 struct iicbus_ivar *devi = IICBUS_IVAR(child); 161 162 device_printf(bus, "<unknown card> at addr %#x\n", devi->addr); 163} 164 165static int 166iicbus_child_location_str(device_t bus, device_t child, char *buf, 167 size_t buflen) 168{ 169 struct iicbus_ivar *devi = IICBUS_IVAR(child); 170 171 snprintf(buf, buflen, "addr=%#x", devi->addr); 172 return (0); 173} 174 175static int 176iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf, 177 size_t buflen) 178{ 179 *buf = '\0'; 180 return (0); 181} 182 183static int 184iicbus_read_ivar(device_t bus, device_t child, int which, uintptr_t *result) 185{ 186 struct iicbus_ivar *devi = IICBUS_IVAR(child); 187 188 switch (which) { 189 default: 190 return (EINVAL); 191 case IICBUS_IVAR_ADDR: 192 *result = devi->addr; 193 break; 194 } 195 return (0); 196} 197 198static device_t 199iicbus_add_child(device_t dev, u_int order, const char *name, int unit) 200{ 201 device_t child; 202 struct iicbus_ivar *devi; 203 204 child = device_add_child_ordered(dev, order, name, unit); 205 if (child == NULL) 206 return (child); 207 devi = malloc(sizeof(struct iicbus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO); 208 if (devi == NULL) { 209 device_delete_child(dev, child); 210 return (0); 211 } 212 resource_list_init(&devi->rl); 213 device_set_ivars(child, devi); 214 return (child); 215} 216 217static void 218iicbus_hinted_child(device_t bus, const char *dname, int dunit) 219{ 220 device_t child; 221 int irq; 222 struct iicbus_ivar *devi; 223 224 child = BUS_ADD_CHILD(bus, 0, dname, dunit); 225 devi = IICBUS_IVAR(child); 226 resource_int_value(dname, dunit, "addr", &devi->addr); 227 if (resource_int_value(dname, dunit, "irq", &irq) == 0) { 228 if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0) 229 device_printf(bus, 230 "warning: bus_set_resource() failed\n"); 231 } 232} 233 234static struct resource_list * 235iicbus_get_resource_list(device_t bus __unused, device_t child) 236{ 237 struct iicbus_ivar *devi; 238 239 devi = IICBUS_IVAR(child); 240 return (&devi->rl); 241} 242 243int 244iicbus_generic_intr(device_t dev, int event, char *buf) 245{ 246 247 return (0); 248} 249 250int 251iicbus_null_callback(device_t dev, int index, caddr_t data) 252{ 253 254 return (0); 255} 256 257int 258iicbus_null_repeated_start(device_t dev, u_char addr) 259{ 260 261 return (IIC_ENOTSUPP); 262} 263 264void 265iicbus_init_frequency(device_t dev, u_int bus_freq) 266{ 267 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 268 269 /* 270 * If a bus frequency value was passed in, use it. Otherwise initialize 271 * it first to the standard i2c 100KHz frequency, then override that 272 * from a hint if one exists. 273 */ 274 if (bus_freq > 0) 275 sc->bus_freq = bus_freq; 276 else { 277 sc->bus_freq = 100000; 278 resource_int_value(device_get_name(dev), device_get_unit(dev), 279 "frequency", (int *)&sc->bus_freq); 280 } 281 /* 282 * Set up the sysctl that allows the bus frequency to be changed. 283 * It is flagged as a tunable so that the user can set the value in 284 * loader(8), and that will override any other setting from any source. 285 * The sysctl tunable/value is the one most directly controlled by the 286 * user and thus the one that always takes precedence. 287 */ 288 SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev), 289 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 290 OID_AUTO, "frequency", CTLFLAG_RW | CTLFLAG_TUN, &sc->bus_freq, 291 sc->bus_freq, "Bus frequency in Hz"); 292} 293 294static u_int 295iicbus_get_frequency(device_t dev, u_char speed) 296{ 297 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 298 299 /* 300 * If the frequency has not been configured for the bus, or the request 301 * is specifically for SLOW speed, use the standard 100KHz rate, else 302 * use the configured bus speed. 303 */ 304 if (sc->bus_freq == 0 || speed == IIC_SLOW) 305 return (100000); 306 return (sc->bus_freq); 307} 308 309static device_method_t iicbus_methods[] = { 310 /* device interface */ 311 DEVMETHOD(device_probe, iicbus_probe), 312 DEVMETHOD(device_attach, iicbus_attach), 313 DEVMETHOD(device_detach, iicbus_detach), 314 315 /* bus interface */ 316 DEVMETHOD(bus_setup_intr, bus_generic_setup_intr), 317 DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr), 318 DEVMETHOD(bus_activate_resource, bus_generic_activate_resource), 319 DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource), 320 DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource), 321 DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource), 322 DEVMETHOD(bus_get_resource, bus_generic_rl_get_resource), 323 DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource), 324 DEVMETHOD(bus_set_resource, bus_generic_rl_set_resource), 325 DEVMETHOD(bus_get_resource_list, iicbus_get_resource_list), 326 DEVMETHOD(bus_add_child, iicbus_add_child), 327 DEVMETHOD(bus_print_child, iicbus_print_child), 328 DEVMETHOD(bus_probe_nomatch, iicbus_probe_nomatch), 329 DEVMETHOD(bus_read_ivar, iicbus_read_ivar), 330 DEVMETHOD(bus_child_pnpinfo_str, iicbus_child_pnpinfo_str), 331 DEVMETHOD(bus_child_location_str, iicbus_child_location_str), 332 DEVMETHOD(bus_hinted_child, iicbus_hinted_child), 333 334 /* iicbus interface */ 335 DEVMETHOD(iicbus_transfer, iicbus_transfer), 336 DEVMETHOD(iicbus_get_frequency, iicbus_get_frequency), 337 338 DEVMETHOD_END 339}; 340 341driver_t iicbus_driver = { 342 "iicbus", 343 iicbus_methods, 344 sizeof(struct iicbus_softc), 345}; 346 347devclass_t iicbus_devclass; 348 349MODULE_VERSION(iicbus, IICBUS_MODVER); 350DRIVER_MODULE(iicbus, iichb, iicbus_driver, iicbus_devclass, 0, 0); 351