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("$FreeBSD$"); 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/sysctl.h> 42 #include <sys/bus.h> 43 44 #include <dev/iicbus/iiconf.h> 45 #include <dev/iicbus/iicbus.h> 46 47 #include "iicbus_if.h" 48 49 /* See comments below for why auto-scanning is a bad idea. */ 50 #define SCAN_IICBUS 0 51 52 static int 53 iicbus_probe(device_t dev) 54 { 55 56 device_set_desc(dev, "Philips I2C bus"); 57 58 /* Allow other subclasses to override this driver. */ 59 return (BUS_PROBE_GENERIC); 60 } 61 62 #if SCAN_IICBUS 63 static int 64 iic_probe_device(device_t dev, u_char addr) 65 { 66 int count; 67 char byte; 68 69 if ((addr & 1) == 0) { 70 /* is device writable? */ 71 if (!iicbus_start(dev, (u_char)addr, 0)) { 72 iicbus_stop(dev); 73 return (1); 74 } 75 } else { 76 /* is device readable? */ 77 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count)) 78 return (1); 79 } 80 81 return (0); 82 } 83 #endif 84 85 /* 86 * We add all the devices which we know about. 87 * The generic attach routine will attach them if they are alive. 88 */ 89 static int 90 iicbus_attach(device_t dev) 91 { 92 #if SCAN_IICBUS 93 unsigned char addr; 94 #endif 95 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 96 int strict; 97 98 sc->dev = dev; 99 mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF); 100 iicbus_init_frequency(dev, 0); 101 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 102 if (resource_int_value(device_get_name(dev), 103 device_get_unit(dev), "strict", &strict) == 0) 104 sc->strict = strict; 105 else 106 sc->strict = 1; 107 108 /* device probing is meaningless since the bus is supposed to be 109 * hot-plug. Moreover, some I2C chips do not appreciate random 110 * accesses like stop after start to fast, reads for less than 111 * x bytes... 112 */ 113 #if SCAN_IICBUS 114 printf("Probing for devices on iicbus%d:", device_get_unit(dev)); 115 116 /* probe any devices */ 117 for (addr = 16; addr < 240; addr++) { 118 if (iic_probe_device(dev, (u_char)addr)) { 119 printf(" <%x>", addr); 120 } 121 } 122 printf("\n"); 123 #endif 124 bus_generic_probe(dev); 125 bus_enumerate_hinted_children(dev); 126 bus_generic_attach(dev); 127 return (0); 128 } 129 130 static int 131 iicbus_detach(device_t dev) 132 { 133 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 134 135 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 136 bus_generic_detach(dev); 137 mtx_destroy(&sc->lock); 138 return (0); 139 } 140 141 static int 142 iicbus_print_child(device_t dev, device_t child) 143 { 144 struct iicbus_ivar *devi = IICBUS_IVAR(child); 145 int retval = 0; 146 147 retval += bus_print_child_header(dev, child); 148 if (devi->addr != 0) 149 retval += printf(" at addr %#x", devi->addr); 150 retval += bus_print_child_footer(dev, child); 151 152 return (retval); 153 } 154 155 static void 156 iicbus_probe_nomatch(device_t bus, device_t child) 157 { 158 struct iicbus_ivar *devi = IICBUS_IVAR(child); 159 160 device_printf(bus, "<unknown card>"); 161 printf(" at addr %#x\n", devi->addr); 162 return; 163 } 164 165 static int 166 iicbus_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 } 174 175 static int 176 iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf, 177 size_t buflen) 178 { 179 *buf = '\0'; 180 return (0); 181 } 182 183 static int 184 iicbus_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 } 197 198 static device_t 199 iicbus_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 device_set_ivars(child, devi); 213 return (child); 214 } 215 216 static void 217 iicbus_hinted_child(device_t bus, const char *dname, int dunit) 218 { 219 device_t child; 220 struct iicbus_ivar *devi; 221 222 child = BUS_ADD_CHILD(bus, 0, dname, dunit); 223 devi = IICBUS_IVAR(child); 224 resource_int_value(dname, dunit, "addr", &devi->addr); 225 } 226 227 int 228 iicbus_generic_intr(device_t dev, int event, char *buf) 229 { 230 231 return (0); 232 } 233 234 int 235 iicbus_null_callback(device_t dev, int index, caddr_t data) 236 { 237 238 return (0); 239 } 240 241 int 242 iicbus_null_repeated_start(device_t dev, u_char addr) 243 { 244 245 return (IIC_ENOTSUPP); 246 } 247 248 void 249 iicbus_init_frequency(device_t dev, u_int bus_freq) 250 { 251 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 252 253 /* 254 * If a bus frequency value was passed in, use it. Otherwise initialize 255 * it first to the standard i2c 100KHz frequency, then override that 256 * from a hint if one exists. 257 */ 258 if (bus_freq > 0) 259 sc->bus_freq = bus_freq; 260 else { 261 sc->bus_freq = 100000; 262 resource_int_value(device_get_name(dev), device_get_unit(dev), 263 "frequency", (int *)&sc->bus_freq); 264 } 265 /* 266 * Set up the sysctl that allows the bus frequency to be changed. 267 * It is flagged as a tunable so that the user can set the value in 268 * loader(8), and that will override any other setting from any source. 269 * The sysctl tunable/value is the one most directly controlled by the 270 * user and thus the one that always takes precedence. 271 */ 272 SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev), 273 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)), 274 OID_AUTO, "frequency", CTLFLAG_RW | CTLFLAG_TUN, &sc->bus_freq, 275 sc->bus_freq, "Bus frequency in Hz"); 276 } 277 278 static u_int 279 iicbus_get_frequency(device_t dev, u_char speed) 280 { 281 struct iicbus_softc *sc = IICBUS_SOFTC(dev); 282 283 /* 284 * If the frequency has not been configured for the bus, or the request 285 * is specifically for SLOW speed, use the standard 100KHz rate, else 286 * use the configured bus speed. 287 */ 288 if (sc->bus_freq == 0 || speed == IIC_SLOW) 289 return (100000); 290 return (sc->bus_freq); 291 } 292 293 static device_method_t iicbus_methods[] = { 294 /* device interface */ 295 DEVMETHOD(device_probe, iicbus_probe), 296 DEVMETHOD(device_attach, iicbus_attach), 297 DEVMETHOD(device_detach, iicbus_detach), 298 299 /* bus interface */ 300 DEVMETHOD(bus_add_child, iicbus_add_child), 301 DEVMETHOD(bus_print_child, iicbus_print_child), 302 DEVMETHOD(bus_probe_nomatch, iicbus_probe_nomatch), 303 DEVMETHOD(bus_read_ivar, iicbus_read_ivar), 304 DEVMETHOD(bus_child_pnpinfo_str, iicbus_child_pnpinfo_str), 305 DEVMETHOD(bus_child_location_str, iicbus_child_location_str), 306 DEVMETHOD(bus_hinted_child, iicbus_hinted_child), 307 308 /* iicbus interface */ 309 DEVMETHOD(iicbus_transfer, iicbus_transfer), 310 DEVMETHOD(iicbus_get_frequency, iicbus_get_frequency), 311 312 DEVMETHOD_END 313 }; 314 315 driver_t iicbus_driver = { 316 "iicbus", 317 iicbus_methods, 318 sizeof(struct iicbus_softc), 319 }; 320 321 devclass_t iicbus_devclass; 322 323 MODULE_VERSION(iicbus, IICBUS_MODVER); 324 DRIVER_MODULE(iicbus, iichb, iicbus_driver, iicbus_devclass, 0, 0); 325 326