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 * $FreeBSD: src/sys/dev/iicbus/iicbus.c,v 1.29 2009/02/10 22:50:23 imp Exp $
27 */
28
29 /*
30 * Autoconfiguration and support routines for the Philips serial I2C bus
31 */
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/bus.h>
38
39 #include <bus/iicbus/iiconf.h>
40 #include <bus/iicbus/iicbus.h>
41
42 #include "iicbus_if.h"
43
44 #define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev))
45
46 devclass_t iicbus_devclass;
47
48 /* See comments below for why auto-scanning is a bad idea. */
49 #define SCAN_IICBUS 0
50
51 /*
52 * Device methods
53 */
54 static int iicbus_probe(device_t);
55 static int iicbus_attach(device_t);
56 static int iicbus_detach(device_t);
57 static int iicbus_add_child(device_t dev, int order, const char *name, int unit);
58
59 static device_method_t iicbus_methods[] = {
60 /* device interface */
61 DEVMETHOD(device_probe, iicbus_probe),
62 DEVMETHOD(device_attach, iicbus_attach),
63 DEVMETHOD(device_detach, iicbus_detach),
64
65 /* bus interface */
66 DEVMETHOD(bus_add_child, iicbus_add_child),
67 DEVMETHOD(bus_driver_added, bus_generic_driver_added),
68 DEVMETHOD(bus_print_child, bus_generic_print_child),
69
70 DEVMETHOD(iicbus_transfer, iicbus_transfer_gen),
71
72 DEVMETHOD_END
73 };
74
75 driver_t iicbus_driver = {
76 "iicbus",
77 iicbus_methods,
78 sizeof(struct iicbus_softc),
79 };
80
81 static int
iicbus_probe(device_t dev)82 iicbus_probe(device_t dev)
83 {
84
85 device_set_desc(dev, "Philips I2C bus");
86
87 /* Allow other subclasses to override this driver. */
88 return (BUS_PROBE_GENERIC);
89 }
90
91 #if SCAN_IICBUS
92 static int
iic_probe_device(device_t dev,u_char addr)93 iic_probe_device(device_t dev, u_char addr)
94 {
95 int count;
96 char byte;
97
98 if ((addr & 1) == 0) {
99 /* is device writable? */
100 if (!iicbus_start(dev, addr, 0)) {
101 iicbus_stop(dev);
102 return (1);
103 }
104 } else {
105 /* is device readable? */
106 if (!iicbus_block_read(dev, addr, &byte, 1, &count))
107 return (1);
108 }
109
110 return (0);
111 }
112 #endif
113
114 /*
115 * We add all the devices which we know about.
116 * The generic attach routine will attach them if they are alive.
117 */
118 static int
iicbus_attach(device_t dev)119 iicbus_attach(device_t dev)
120 {
121 #if SCAN_IICBUS
122 unsigned char addr;
123 #endif
124
125 iicbus_reset(dev, IIC_FASTEST, 0, NULL);
126
127 /* device probing is meaningless since the bus is supposed to be
128 * hot-plug. Moreover, some I2C chips do not appreciate random
129 * accesses like stop after start to fast, reads for less than
130 * x bytes...
131 */
132 #if SCAN_IICBUS
133 kprintf("Probing for devices on iicbus%d:", device_get_unit(dev));
134
135 /* probe any devices */
136 for (addr = 16; addr < 240; addr++) {
137 if (iic_probe_device(dev, (u_char)addr)) {
138 kprintf(" <%x>", addr);
139 }
140 }
141 kprintf("\n");
142 #endif
143
144 device_add_child(dev, "ic", -1);
145 device_add_child(dev, "iic", -1);
146 device_add_child(dev, "iicsmb", -1);
147 #if 0
148 /* attach any known device */
149 device_add_child(dev, "iic", -1);
150 #endif
151 bus_generic_attach(dev);
152
153 return (0);
154 }
155
156 static int
iicbus_detach(device_t dev)157 iicbus_detach(device_t dev)
158 {
159 iicbus_reset(dev, IIC_FASTEST, 0, NULL);
160 bus_generic_detach(dev);
161 return (0);
162 }
163
164 static int
iicbus_add_child(device_t dev,int order,const char * name,int unit)165 iicbus_add_child(device_t dev, int order, const char *name, int unit)
166 {
167
168 device_add_child_ordered(dev, order, name, unit);
169 bus_generic_attach(dev);
170 return (0);
171 }
172
173 int
iicbus_generic_intr(device_t dev,int event,char * buf)174 iicbus_generic_intr(device_t dev, int event, char *buf)
175 {
176
177 return (0);
178 }
179
180 int
iicbus_null_callback(device_t dev,int index,caddr_t data)181 iicbus_null_callback(device_t dev, int index, caddr_t data)
182 {
183
184 return (0);
185 }
186
187 int
iicbus_null_repeated_start(device_t dev,u_char addr)188 iicbus_null_repeated_start(device_t dev, u_char addr)
189 {
190
191 return (IIC_ENOTSUPP);
192 }
193
194 DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, NULL, NULL);
195 MODULE_VERSION(iicbus, IICBUS_MODVER);
196