sys/bus/iicbus/iicbus.c

   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);