2 * Copyright (c) 1998 Nicolas Souchu
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
26 * $FreeBSD: src/sys/dev/iicbus/iicbus.c,v 1.13 1999/12/03 08:41:02 mdodd Exp $
31 * Autoconfiguration and support routines for the Philips serial I2C bus
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
40 #include <machine/clock.h>
42 #include <dev/iicbus/iiconf.h>
43 #include <dev/iicbus/iicbus.h>
45 #include "iicbus_if.h"
47 #define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev))
50 * structure used to attach devices to the I2C bus
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 */
62 * Common I2C addresses
64 #define I2C_GENERAL_CALL 0x0
65 #define PCF_MASTER_ADDRESS 0xaa
66 #define FIRST_SLAVE_ADDR 0x2
68 #define LAST_SLAVE_ADDR 255
70 #define IICBUS_UNKNOWN_CLASS 0
71 #define IICBUS_DEVICE_CLASS 1
72 #define IICBUS_DRIVER_CLASS 2
75 * list of known devices
77 * XXX only one smb driver should exist for each I2C interface
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" },
83 { "ic", IICBUS_DEVICE_CLASS, "network interface", PCF_MASTER_ADDRESS },
88 static devclass_t iicbus_devclass;
93 static int iicbus_probe(device_t);
94 static int iicbus_attach(device_t);
95 static int 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);
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),
107 DEVMETHOD(bus_print_child, iicbus_print_child),
108 DEVMETHOD(bus_read_ivar, iicbus_read_ivar),
109 DEVMETHOD(bus_write_ivar, iicbus_write_ivar),
114 static driver_t iicbus_driver = {
117 sizeof(struct iicbus_softc),
121 iicbus_probe(device_t dev)
123 device_set_desc(dev, "Philips I2C bus");
130 iic_probe_device(device_t dev, u_char addr)
135 if ((addr & 1) == 0) {
136 /* is device writable? */
137 if (!iicbus_start(dev, (u_char)addr, 0)) {
142 /* is device readable? */
143 if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count))
152 * We add all the devices which we know about.
153 * The generic attach routine will attach them if they are alive.
156 iicbus_attach(device_t dev)
158 struct iicbus_device *iicdev;
161 iicbus_reset(dev, IIC_FASTEST, 0, NULL);
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
169 printf("Probing for devices on iicbus%d:", device_get_unit(dev));
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);
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",
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",
202 panic("%s: unknown class!", __FUNCTION__);
205 if (iicdev->iicd_alive) {
206 child = device_add_child(dev, iicdev->iicd_name, -1);
207 device_set_ivars(child, iicdev);
208 device_set_desc(child, iicdev->iicd_desc);
211 bus_generic_attach(dev);
217 iicbus_generic_intr(device_t dev, int event, char *buf)
223 iicbus_null_callback(device_t dev, int index, caddr_t data)
229 iicbus_null_repeated_start(device_t dev, u_char addr)
231 return (IIC_ENOTSUPP);
235 iicbus_print_child(device_t bus, device_t dev)
237 struct iicbus_device* iicdev = DEVTOIICBUS(dev);
240 retval += bus_print_child_header(bus, dev);
242 switch (iicdev->iicd_class) {
243 case IICBUS_DEVICE_CLASS:
244 retval += printf(" on %s addr 0x%x\n",
245 device_get_nameunit(bus), iicdev->iicd_addr);
248 case IICBUS_DRIVER_CLASS:
249 retval += bus_print_child_footer(bus, dev);
253 panic("%s: unknown class!", __FUNCTION__);
260 iicbus_read_ivar(device_t bus, device_t dev, int index, u_long* result)
262 struct iicbus_device* iicdev = DEVTOIICBUS(dev);
265 case IICBUS_IVAR_ADDR:
266 *result = (u_long)iicdev->iicd_addr;
277 iicbus_write_ivar(device_t bus, device_t dev, int index, u_long val)
287 DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0);
288 DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
289 DRIVER_MODULE(iicbus, bti2c, iicbus_driver, iicbus_devclass, 0, 0);