1 /*- 2 * Copyright (c) 1998 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 * $FreeBSD: src/sys/dev/iicbus/iicbus.c,v 1.13 1999/12/03 08:41:02 mdodd Exp $ 27 * $DragonFly: src/sys/bus/iicbus/iicbus.c,v 1.5 2006/12/22 23:12:16 swildner Exp $ 28 * 29 */ 30 31 /* 32 * Autoconfiguration and support routines for the Philips serial I2C bus 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/kernel.h> 38 #include <sys/module.h> 39 #include <sys/bus.h> 40 41 #include <machine/clock.h> 42 43 #include "iiconf.h" 44 #include "iicbus.h" 45 46 #include "iicbus_if.h" 47 48 #define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev)) 49 50 /* 51 * structure used to attach devices to the I2C bus 52 */ 53 struct iicbus_device { 54 const char *iicd_name; /* device name */ 55 int iicd_class; /* driver or slave device class */ 56 const char *iicd_desc; /* device descriptor */ 57 u_char iicd_addr; /* address of the device */ 58 int iicd_waitack; /* wait for ack timeout or delay */ 59 int iicd_alive; /* 1 if device found */ 60 }; 61 62 /* 63 * Common I2C addresses 64 */ 65 #define I2C_GENERAL_CALL 0x0 66 #define PCF_MASTER_ADDRESS 0xaa 67 #define FIRST_SLAVE_ADDR 0x2 68 69 #define LAST_SLAVE_ADDR 255 70 71 #define IICBUS_UNKNOWN_CLASS 0 72 #define IICBUS_DEVICE_CLASS 1 73 #define IICBUS_DRIVER_CLASS 2 74 75 /* 76 * list of known devices 77 * 78 * XXX only one smb driver should exist for each I2C interface 79 */ 80 static struct iicbus_device iicbus_children[] = { 81 { "iicsmb", IICBUS_DRIVER_CLASS, "I2C to SMB bridge" }, 82 { "iic", IICBUS_DRIVER_CLASS, "I2C general purpose I/O" }, 83 #if 0 84 { "ic", IICBUS_DEVICE_CLASS, "network interface", PCF_MASTER_ADDRESS }, 85 #endif 86 { NULL, 0 } 87 }; 88 89 static devclass_t iicbus_devclass; 90 91 /* 92 * Device methods 93 */ 94 static int iicbus_probe(device_t); 95 static int iicbus_attach(device_t); 96 static int iicbus_print_child(device_t, device_t); 97 static int iicbus_read_ivar(device_t , device_t, int, u_long *); 98 static int iicbus_write_ivar(device_t , device_t, int, u_long); 99 100 static device_method_t iicbus_methods[] = { 101 /* device interface */ 102 DEVMETHOD(device_probe, iicbus_probe), 103 DEVMETHOD(device_attach, iicbus_attach), 104 DEVMETHOD(device_detach, bus_generic_detach), 105 DEVMETHOD(device_shutdown, bus_generic_shutdown), 106 107 /* bus interface */ 108 DEVMETHOD(bus_print_child, iicbus_print_child), 109 DEVMETHOD(bus_read_ivar, iicbus_read_ivar), 110 DEVMETHOD(bus_write_ivar, iicbus_write_ivar), 111 112 { 0, 0 } 113 }; 114 115 static driver_t iicbus_driver = { 116 "iicbus", 117 iicbus_methods, 118 sizeof(struct iicbus_softc), 119 }; 120 121 static int 122 iicbus_probe(device_t dev) 123 { 124 device_set_desc(dev, "Philips I2C bus"); 125 126 return (0); 127 } 128 129 #if 0 130 static int 131 iic_probe_device(device_t dev, u_char addr) 132 { 133 int count; 134 char byte; 135 136 if ((addr & 1) == 0) { 137 /* is device writable? */ 138 if (!iicbus_start(dev, (u_char)addr, 0)) { 139 iicbus_stop(dev); 140 return (1); 141 } 142 } else { 143 /* is device readable? */ 144 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count)) 145 return (1); 146 } 147 148 return (0); 149 } 150 #endif 151 152 /* 153 * We add all the devices which we know about. 154 * The generic attach routine will attach them if they are alive. 155 */ 156 static int 157 iicbus_attach(device_t dev) 158 { 159 struct iicbus_device *iicdev; 160 device_t child; 161 162 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 163 164 /* device probing is meaningless since the bus is supposed to be 165 * hot-plug. Moreover, some I2C chips do not appreciate random 166 * accesses like stop after start to fast, reads for less than 167 * x bytes... 168 */ 169 #if 0 170 kprintf("Probing for devices on iicbus%d:", device_get_unit(dev)); 171 172 /* probe any devices */ 173 for (addr = FIRST_SLAVE_ADDR; addr <= LAST_SLAVE_ADDR; addr++) { 174 if (iic_probe_device(dev, (u_char)addr)) { 175 kprintf(" <%x>", addr); 176 } 177 } 178 kprintf("\n"); 179 #endif 180 181 /* attach known devices */ 182 for (iicdev = iicbus_children; iicdev->iicd_name; iicdev++) { 183 switch (iicdev->iicd_class) { 184 case IICBUS_DEVICE_CLASS: 185 /* check if the devclass exists */ 186 if (devclass_find(iicdev->iicd_name)) 187 iicdev->iicd_alive = 1; 188 else if (bootverbose) 189 kprintf("iicbus: %s devclass not found\n", 190 iicdev->iicd_name); 191 break; 192 193 case IICBUS_DRIVER_CLASS: 194 /* check if the devclass exists */ 195 if (devclass_find(iicdev->iicd_name)) 196 iicdev->iicd_alive = 1; 197 else if (bootverbose) 198 kprintf("iicbus: %s devclass not found\n", 199 iicdev->iicd_name); 200 break; 201 202 default: 203 panic("%s: unknown class!", __func__); 204 } 205 206 if (iicdev->iicd_alive) { 207 child = device_add_child(dev, iicdev->iicd_name, -1); 208 device_set_ivars(child, iicdev); 209 device_set_desc(child, iicdev->iicd_desc); 210 } 211 } 212 bus_generic_attach(dev); 213 214 return (0); 215 } 216 217 int 218 iicbus_generic_intr(device_t dev, int event, char *buf) 219 { 220 return (0); 221 } 222 223 int 224 iicbus_null_callback(device_t dev, int index, caddr_t data) 225 { 226 return (0); 227 } 228 229 int 230 iicbus_null_repeated_start(device_t dev, u_char addr) 231 { 232 return (IIC_ENOTSUPP); 233 } 234 235 static int 236 iicbus_print_child(device_t bus, device_t dev) 237 { 238 struct iicbus_device* iicdev = DEVTOIICBUS(dev); 239 int retval = 0; 240 241 retval += bus_print_child_header(bus, dev); 242 243 switch (iicdev->iicd_class) { 244 case IICBUS_DEVICE_CLASS: 245 retval += kprintf(" on %s addr 0x%x\n", 246 device_get_nameunit(bus), iicdev->iicd_addr); 247 break; 248 249 case IICBUS_DRIVER_CLASS: 250 retval += bus_print_child_footer(bus, dev); 251 break; 252 253 default: 254 panic("%s: unknown class!", __func__); 255 } 256 257 return (retval); 258 } 259 260 static int 261 iicbus_read_ivar(device_t bus, device_t dev, int index, u_long* result) 262 { 263 struct iicbus_device* iicdev = DEVTOIICBUS(dev); 264 265 switch (index) { 266 case IICBUS_IVAR_ADDR: 267 *result = (u_long)iicdev->iicd_addr; 268 break; 269 270 default: 271 return (ENOENT); 272 } 273 274 return (0); 275 } 276 277 static int 278 iicbus_write_ivar(device_t bus, device_t dev, int index, u_long val) 279 { 280 switch (index) { 281 default: 282 return (ENOENT); 283 } 284 285 return (0); 286 } 287 288 DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0); 289 DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0); 290 DRIVER_MODULE(iicbus, bti2c, iicbus_driver, iicbus_devclass, 0, 0); 291