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 * $Id: iicbus.c,v 1.8 1999/04/11 02:55:52 eivind Exp $ 27 * 28 */ 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 #include <machine/clock.h> 41 42 #include <dev/iicbus/iiconf.h> 43 #include <dev/iicbus/iicbus.h> 44 45 #include "iicbus_if.h" 46 47 #define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev)) 48 49 /* 50 * structure used to attach devices to the I2C bus 51 */ 52 struct iicbus_device { 53 const char *iicd_name; /* device name */ 54 int iicd_class; /* driver or slave device class */ 55 const char *iicd_desc; /* device descriptor */ 56 u_char iicd_addr; /* address of the device */ 57 int iicd_waitack; /* wait for ack timeout or delay */ 58 int iicd_alive; /* 1 if device found */ 59 }; 60 61 /* 62 * Common I2C addresses 63 */ 64 #define I2C_GENERAL_CALL 0x0 65 #define PCF_MASTER_ADDRESS 0xaa 66 #define FIRST_SLAVE_ADDR 0x2 67 68 #define LAST_SLAVE_ADDR 255 69 70 #define IICBUS_UNKNOWN_CLASS 0 71 #define IICBUS_DEVICE_CLASS 1 72 #define IICBUS_DRIVER_CLASS 2 73 74 /* 75 * list of known devices 76 * 77 * XXX only one smb driver should exist for each I2C interface 78 */ 79 static struct iicbus_device iicbus_children[] = { 80 { "iicsmb", IICBUS_DRIVER_CLASS, "I2C to SMB bridge" }, 81 { "iic", IICBUS_DRIVER_CLASS, "I2C general purpose I/O" }, 82 #if 0 83 { "ic", IICBUS_DEVICE_CLASS, "network interface", PCF_MASTER_ADDRESS }, 84 #endif 85 { NULL, 0 } 86 }; 87 88 static devclass_t iicbus_devclass; 89 90 /* 91 * Device methods 92 */ 93 static int iicbus_probe(device_t); 94 static int iicbus_attach(device_t); 95 static void iicbus_print_child(device_t, device_t); 96 static int iicbus_read_ivar(device_t , device_t, int, u_long *); 97 static int iicbus_write_ivar(device_t , device_t, int, u_long); 98 99 static device_method_t iicbus_methods[] = { 100 /* device interface */ 101 DEVMETHOD(device_probe, iicbus_probe), 102 DEVMETHOD(device_attach, iicbus_attach), 103 DEVMETHOD(device_detach, bus_generic_detach), 104 DEVMETHOD(device_shutdown, bus_generic_shutdown), 105 106 /* bus interface */ 107 DEVMETHOD(bus_print_child, iicbus_print_child), 108 DEVMETHOD(bus_read_ivar, iicbus_read_ivar), 109 DEVMETHOD(bus_write_ivar, iicbus_write_ivar), 110 111 { 0, 0 } 112 }; 113 114 static driver_t iicbus_driver = { 115 "iicbus", 116 iicbus_methods, 117 sizeof(struct iicbus_softc), 118 }; 119 120 static int 121 iicbus_probe(device_t dev) 122 { 123 device_set_desc(dev, "Philips I2C bus"); 124 125 return (0); 126 } 127 128 #if 0 129 static int 130 iic_probe_device(device_t dev, u_char addr) 131 { 132 int count; 133 char byte; 134 135 if ((addr & 1) == 0) { 136 /* is device writable? */ 137 if (!iicbus_start(dev, (u_char)addr, 0)) { 138 iicbus_stop(dev); 139 return (1); 140 } 141 } else { 142 /* is device readable? */ 143 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count)) 144 return (1); 145 } 146 147 return (0); 148 } 149 #endif 150 151 /* 152 * We add all the devices which we know about. 153 * The generic attach routine will attach them if they are alive. 154 */ 155 static int 156 iicbus_attach(device_t dev) 157 { 158 struct iicbus_device *iicdev; 159 device_t child; 160 161 iicbus_reset(dev, IIC_FASTEST, 0, NULL); 162 163 /* device probing is meaningless since the bus is supposed to be 164 * hot-plug. Moreover, some I2C chips do not appreciate random 165 * accesses like stop after start to fast, reads for less than 166 * x bytes... 167 */ 168 #if 0 169 printf("Probing for devices on iicbus%d:", device_get_unit(dev)); 170 171 /* probe any devices */ 172 for (addr = FIRST_SLAVE_ADDR; addr <= LAST_SLAVE_ADDR; addr++) { 173 if (iic_probe_device(dev, (u_char)addr)) { 174 printf(" <%x>", addr); 175 } 176 } 177 printf("\n"); 178 #endif 179 180 /* attach known devices */ 181 for (iicdev = iicbus_children; iicdev->iicd_name; iicdev++) { 182 switch (iicdev->iicd_class) { 183 case IICBUS_DEVICE_CLASS: 184 /* check if the devclass exists */ 185 if (devclass_find(iicdev->iicd_name)) 186 iicdev->iicd_alive = 1; 187 else if (bootverbose) 188 printf("iicbus: %s devclass not found\n", 189 iicdev->iicd_name); 190 break; 191 192 case IICBUS_DRIVER_CLASS: 193 /* check if the devclass exists */ 194 if (devclass_find(iicdev->iicd_name)) 195 iicdev->iicd_alive = 1; 196 else if (bootverbose) 197 printf("iicbus: %s devclass not found\n", 198 iicdev->iicd_name); 199 break; 200 201 default: 202 panic("%s: unknown class!", __FUNCTION__); 203 } 204 205 if (iicdev->iicd_alive) { 206 child = device_add_child(dev, iicdev->iicd_name, 207 -1, iicdev); 208 device_set_desc(child, iicdev->iicd_desc); 209 } 210 } 211 bus_generic_attach(dev); 212 213 return (0); 214 } 215 216 int 217 iicbus_generic_intr(device_t dev, int event, char *buf) 218 { 219 return (0); 220 } 221 222 int 223 iicbus_null_callback(device_t dev, int index, caddr_t data) 224 { 225 return (0); 226 } 227 228 int 229 iicbus_null_repeated_start(device_t dev, u_char addr) 230 { 231 return (IIC_ENOTSUPP); 232 } 233 234 static void 235 iicbus_print_child(device_t bus, device_t dev) 236 { 237 struct iicbus_device* iicdev = DEVTOIICBUS(dev); 238 239 switch (iicdev->iicd_class) { 240 case IICBUS_DEVICE_CLASS: 241 printf(" on %s%d addr 0x%x", device_get_name(bus), 242 device_get_unit(bus), iicdev->iicd_addr); 243 break; 244 245 case IICBUS_DRIVER_CLASS: 246 printf(" on %s%d", device_get_name(bus), 247 device_get_unit(bus)); 248 break; 249 250 default: 251 panic("%s: unknown class!", __FUNCTION__); 252 } 253 254 return; 255 } 256 257 static int 258 iicbus_read_ivar(device_t bus, device_t dev, int index, u_long* result) 259 { 260 struct iicbus_device* iicdev = DEVTOIICBUS(dev); 261 262 switch (index) { 263 case IICBUS_IVAR_ADDR: 264 *result = (u_long)iicdev->iicd_addr; 265 break; 266 267 default: 268 return (ENOENT); 269 } 270 271 return (0); 272 } 273 274 static int 275 iicbus_write_ivar(device_t bus, device_t dev, int index, u_long val) 276 { 277 switch (index) { 278 default: 279 return (ENOENT); 280 } 281 282 return (0); 283 } 284 285 DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0); 286 DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0); 287 DRIVER_MODULE(iicbus, bti2c, iicbus_driver, iicbus_devclass, 0, 0); 288