iicbus.c revision 167856 
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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/dev/iicbus/iicbus.c 167856 2007-03-23 23:08:28Z imp $");
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/malloc.h>
38#include <sys/module.h>
39#include <sys/bus.h>
40
41#include <dev/iicbus/iiconf.h>
42#include <dev/iicbus/iicbus.h>
43
44#include "iicbus_if.h"
45
46/* See comments below for why auto-scanning is a bad idea. */
47#define SCAN_IICBUS 0
48
49static int
50iicbus_probe(device_t dev)
51{
52
53	device_set_desc(dev, "Philips I2C bus");
54	return (0);
55}
56
57#if SCAN_IICBUS
58static int
59iic_probe_device(device_t dev, u_char addr)
60{
61	int count;
62	char byte;
63
64	if ((addr & 1) == 0) {
65		/* is device writable? */
66		if (!iicbus_start(dev, (u_char)addr, 0)) {
67			iicbus_stop(dev);
68			return (1);
69		}
70	} else {
71		/* is device readable? */
72		if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count))
73			return (1);
74	}
75
76	return (0);
77}
78#endif
79
80/*
81 * We add all the devices which we know about.
82 * The generic attach routine will attach them if they are alive.
83 */
84static int
85iicbus_attach(device_t dev)
86{
87#if SCAN_IICBUS
88	unsigned char addr;
89#endif
90	struct iicbus_softc *sc = IICBUS_SOFTC(dev);
91
92	sc->dev = dev;
93	iicbus_reset(dev, IIC_FASTEST, 0, NULL);
94
95	/* device probing is meaningless since the bus is supposed to be
96	 * hot-plug. Moreover, some I2C chips do not appreciate random
97	 * accesses like stop after start to fast, reads for less than
98	 * x bytes...
99	 */
100#if SCAN_IICBUS
101	printf("Probing for devices on iicbus%d:", device_get_unit(dev));
102
103	/* probe any devices */
104	for (addr = 16; addr < 240; addr++) {
105		if (iic_probe_device(dev, (u_char)addr)) {
106			printf(" <%x>", addr);
107		}
108	}
109	printf("\n");
110#endif
111	/* Always attach the iicsmb children */
112	BUS_ADD_CHILD(dev, 0, "iicsmb", -1);
113	/* attach any known device */
114	BUS_ADD_CHILD(dev, 0, "iic", -1);
115	/* Attach the wired devices via hints */
116	bus_enumerate_hinted_children(dev);
117	/* Now probe and attach them */
118	bus_generic_attach(dev);
119        return (0);
120}
121
122static int
123iicbus_detach(device_t dev)
124{
125
126	iicbus_reset(dev, IIC_FASTEST, 0, NULL);
127	bus_generic_detach(dev);
128	return (0);
129}
130
131static int
132iicbus_print_child(device_t dev, device_t child)
133{
134	struct iicbus_ivar *devi = IICBUS_IVAR(child);
135	int retval = 0;
136
137	retval += bus_print_child_header(dev, child);
138	if (devi->addr != 0)
139		retval += printf(" at addr %#x", devi->addr);
140	retval += bus_print_child_footer(dev, child);
141
142	return (retval);
143}
144
145static void
146iicbus_probe_nomatch(device_t bus, device_t child)
147{
148	struct iicbus_ivar *devi = IICBUS_IVAR(child);
149
150	device_printf(bus, "<unknown card>");
151	printf(" at addr %#x\n", devi->addr);
152	return;
153}
154
155static int
156iicbus_child_location_str(device_t bus, device_t child, char *buf,
157    size_t buflen)
158{
159	struct iicbus_ivar *devi = IICBUS_IVAR(child);
160
161	snprintf(buf, buflen, "addr=%#x", devi->addr);
162	return (0);
163}
164
165static int
166iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
167    size_t buflen)
168{
169	*buf = '\0';
170	return (0);
171}
172
173static int
174iicbus_read_ivar(device_t bus, device_t child, int which, u_char *result)
175{
176	struct iicbus_ivar *devi = IICBUS_IVAR(child);
177
178	switch (which) {
179	default:
180		return (EINVAL);
181	case IICBUS_IVAR_ADDR:
182		*(uint32_t *)result = devi->addr;
183		break;
184	}
185	return (0);
186}
187
188static device_t
189iicbus_add_child(device_t dev, int order, const char *name, int unit)
190{
191	device_t child;
192	struct iicbus_ivar *devi;
193
194	child = device_add_child_ordered(dev, order, name, unit);
195	if (child == NULL)
196		return (child);
197	devi = malloc(sizeof(struct iicbus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
198	if (devi == NULL) {
199		device_delete_child(dev, child);
200		return (0);
201	}
202	device_set_ivars(child, devi);
203	return (child);
204}
205
206static void
207iicbus_hinted_child(device_t bus, const char *dname, int dunit)
208{
209	device_t child;
210	struct iicbus_ivar *devi;
211
212	child = BUS_ADD_CHILD(bus, 0, dname, dunit);
213	devi = IICBUS_IVAR(child);
214	resource_int_value(dname, dunit, "addr", &devi->addr);
215}
216
217int
218iicbus_generic_intr(device_t dev, int event, char *buf)
219{
220
221	return (0);
222}
223
224int
225iicbus_null_callback(device_t dev, int index, caddr_t data)
226{
227
228	return (0);
229}
230
231int
232iicbus_null_repeated_start(device_t dev, u_char addr)
233{
234
235	return (IIC_ENOTSUPP);
236}
237
238static device_method_t iicbus_methods[] = {
239        /* device interface */
240        DEVMETHOD(device_probe,         iicbus_probe),
241        DEVMETHOD(device_attach,        iicbus_attach),
242        DEVMETHOD(device_detach,        iicbus_detach),
243
244        /* bus interface */
245        DEVMETHOD(bus_add_child,	iicbus_add_child),
246	DEVMETHOD(bus_driver_added,	bus_generic_driver_added),
247        DEVMETHOD(bus_print_child,      iicbus_print_child),
248	DEVMETHOD(bus_probe_nomatch,	iicbus_probe_nomatch),
249	DEVMETHOD(bus_read_ivar,	iicbus_read_ivar),
250	DEVMETHOD(bus_child_pnpinfo_str, iicbus_child_pnpinfo_str),
251	DEVMETHOD(bus_child_location_str, iicbus_child_location_str),
252	DEVMETHOD(bus_hinted_child,	iicbus_hinted_child),
253
254	/* iicbus interface */
255	DEVMETHOD(iicbus_transfer,	iicbus_transfer),
256
257        { 0, 0 }
258};
259
260driver_t iicbus_driver = {
261        "iicbus",
262        iicbus_methods,
263        sizeof(struct iicbus_softc),
264};
265
266devclass_t iicbus_devclass;
267
268DRIVER_MODULE(iicbus, envctrl, iicbus_driver, iicbus_devclass, 0, 0);
269DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
270MODULE_VERSION(iicbus, IICBUS_MODVER);
271