Additional note to last commit. GCC-3.4 improperly generates a warning
[dragonfly.git] / sys / bus / iicbus / iicbus.c
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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 $
5e2195bf 27 * $DragonFly: src/sys/bus/iicbus/iicbus.c,v 1.4 2005/02/17 13:59:35 joerg Exp $
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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
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43#include "iiconf.h"
44#include "iicbus.h"
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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 */
53struct 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 */
80static 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
89static devclass_t iicbus_devclass;
90
91/*
92 * Device methods
93 */
94static int iicbus_probe(device_t);
95static int iicbus_attach(device_t);
96static int iicbus_print_child(device_t, device_t);
97static int iicbus_read_ivar(device_t , device_t, int, u_long *);
98static int iicbus_write_ivar(device_t , device_t, int, u_long);
99
100static 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
115static driver_t iicbus_driver = {
116 "iicbus",
117 iicbus_methods,
118 sizeof(struct iicbus_softc),
119};
120
121static int
122iicbus_probe(device_t dev)
123{
124 device_set_desc(dev, "Philips I2C bus");
125
126 return (0);
127}
128
129#if 0
130static int
131iic_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 */
156static int
157iicbus_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 printf("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 printf(" <%x>", addr);
176 }
177 }
178 printf("\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 printf("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 printf("iicbus: %s devclass not found\n",
199 iicdev->iicd_name);
200 break;
201
202 default:
5e2195bf 203 panic("%s: unknown class!", __func__);
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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
217int
218iicbus_generic_intr(device_t dev, int event, char *buf)
219{
220 return (0);
221}
222
223int
224iicbus_null_callback(device_t dev, int index, caddr_t data)
225{
226 return (0);
227}
228
229int
230iicbus_null_repeated_start(device_t dev, u_char addr)
231{
232 return (IIC_ENOTSUPP);
233}
234
235static int
236iicbus_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 += printf(" 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:
5e2195bf 254 panic("%s: unknown class!", __func__);
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255 }
256
257 return (retval);
258}
259
260static int
261iicbus_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
277static int
278iicbus_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
288DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0);
289DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
290DRIVER_MODULE(iicbus, bti2c, iicbus_driver, iicbus_devclass, 0, 0);