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/module.h> 38 #include <sys/bus.h> 39 40 41 #include <dev/iicbus/iiconf.h> 42 #include <dev/iicbus/iicbus.h> 43 44 #include "iicbus_if.h" 45 46 #define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev)) 47 48 devclass_t iicbus_devclass; 49 50 /* See comments below for why auto-scanning is a bad idea. */ 51 #define SCAN_IICBUS 0 52 53 /* 54 * Device methods 55 */ 56 static int iicbus_probe(device_t); 57 static int iicbus_attach(device_t); 58 static int iicbus_detach(device_t); 59 static int iicbus_add_child(device_t dev, int order, const char *name, int unit); 60 61 static device_method_t iicbus_methods[] = { 62 /* device interface */ 63 DEVMETHOD(device_probe, iicbus_probe), 64 DEVMETHOD(device_attach, iicbus_attach), 65 DEVMETHOD(device_detach, iicbus_detach), 66 67 /* bus interface */ 68 DEVMETHOD(bus_add_child, iicbus_add_child), 69 DEVMETHOD(bus_driver_added, bus_generic_driver_added), 70 DEVMETHOD(bus_print_child, bus_generic_print_child), 71 72 { 0, 0 } 73 }; 74 75 driver_t iicbus_driver = { 76 "iicbus", 77 iicbus_methods, 78 sizeof(struct iicbus_softc), 79 }; 80 81 static int 82 iicbus_probe(device_t dev) 83 { 84 85 device_set_desc(dev, "Philips I2C bus"); 86 return (0); 87 } 88 89 #if SCAN_IICBUS 90 static int 91 iic_probe_device(device_t dev, u_char addr) 92 { 93 int count; 94 char byte; 95 96 if ((addr & 1) == 0) { 97 /* is device writable? */ 98 if (!iicbus_start(dev, (u_char)addr, 0)) { 99 iicbus_stop(dev); 100 return (1); 101 } 102 } else { 103 /* is device readable? */ 104 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count)) 105 return (1); 106 } 107 108 return (0); 109 } 110 #endif 111 112 /* 113 * We add all the devices which we know about. 114 * The generic attach routine will attach them if they are alive. 115 */ 116 static int 117 iicbus_attach(device_t dev) 118 { 119 #if SCAN_IICBUS 120 unsigned char addr; 121 #endif 122 123 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 124 125 /* device probing is meaningless since the bus is supposed to be 126 * hot-plug. Moreover, some I2C chips do not appreciate random 127 * accesses like stop after start to fast, reads for less than 128 * x bytes... 129 */ 130 #if SCAN_IICBUS 131 printf("Probing for devices on iicbus%d:", device_get_unit(dev)); 132 133 /* probe any devices */ 134 for (addr = 16; addr < 240; addr++) { 135 if (iic_probe_device(dev, (u_char)addr)) { 136 printf(" <%x>", addr); 137 } 138 } 139 printf("\n"); 140 #endif 141 142 device_add_child(dev, "ic", -1); 143 device_add_child(dev, "iicsmb", -1); 144 #if 0 145 /* attach any known device */ 146 device_add_child(dev, "iic", -1); 147 #endif 148 bus_generic_attach(dev); 149 return (0); 150 } 151 152 static int 153 iicbus_detach(device_t dev) 154 { 155 156 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 157 bus_generic_detach(dev); 158 return (0); 159 } 160 161 static int 162 iicbus_add_child(device_t dev, int order, const char *name, int unit) 163 { 164 165 device_add_child_ordered(dev, order, name, unit); 166 bus_generic_attach(dev); 167 return (0); 168 } 169 170 int 171 iicbus_generic_intr(device_t dev, int event, char *buf) 172 { 173 174 return (0); 175 } 176 177 int 178 iicbus_null_callback(device_t dev, int index, caddr_t data) 179 { 180 181 return (0); 182 } 183 184 int 185 iicbus_null_repeated_start(device_t dev, u_char addr) 186 { 187 188 return (IIC_ENOTSUPP); 189 } 190 191 DRIVER_MODULE(iicbus, envctrl, iicbus_driver, iicbus_devclass, 0, 0); 192 DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0); 193 MODULE_VERSION(iicbus, IICBUS_MODVER); 194