iicbus.c revision 40782 
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 *	$Id: iicbus.c,v 1.1.1.1 1998/09/03 20:51:50 nsouch Exp $
27 *
28 */
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/module.h>
38#include <sys/bus.h>
39
40#include <machine/clock.h>
41
42#include <dev/iicbus/iiconf.h>
43#include <dev/iicbus/iicbus.h>
44
45#include "iicbus_if.h"
46
47#define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev))
48
49/*
50 * structure used to attach devices to the I2C bus
51 */
52struct 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 */
59};
60
61/*
62 * Common I2C addresses
63 */
64#define I2C_GENERAL_CALL	0x0
65#define PCF_MASTER_ADDRESS	0xaa
66#define FIRST_SLAVE_ADDR	0x2
67
68#define MAXSLAVE 256
69
70#define IICBUS_UNKNOWN_CLASS	0
71#define IICBUS_DEVICE_CLASS	1
72#define IICBUS_DRIVER_CLASS	2
73
74/*
75 * list of known devices
76 */
77struct iicbus_device iicbus_children[] = {
78	{ "iicsmb", IICBUS_DRIVER_CLASS, "I2C to SMB bridge" },
79	{ "iic", IICBUS_DEVICE_CLASS, "PCF8574 I2C to 8 bits parallel i/o", 64},
80	{ "iic", IICBUS_DEVICE_CLASS, "PCF8584 as slave", PCF_MASTER_ADDRESS },
81	{ "ic", IICBUS_DEVICE_CLASS, "network interface", PCF_MASTER_ADDRESS },
82#if 0
83	{ "iic", IICBUS_DRIVER_CLASS, "General Call", I2C_GENERAL_CALL },
84#endif
85	{ NULL, 0 }
86};
87
88static devclass_t iicbus_devclass;
89
90/*
91 * Device methods
92 */
93static int iicbus_probe(device_t);
94static int iicbus_attach(device_t);
95static void iicbus_print_child(device_t, device_t);
96static int iicbus_read_ivar(device_t , device_t, int, u_long *);
97static int iicbus_write_ivar(device_t , device_t, int, u_long);
98
99static 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),
105
106        /* bus interface */
107        DEVMETHOD(bus_print_child,      iicbus_print_child),
108        DEVMETHOD(bus_read_ivar,        iicbus_read_ivar),
109        DEVMETHOD(bus_write_ivar,       iicbus_write_ivar),
110        DEVMETHOD(bus_create_intr,      bus_generic_create_intr),
111        DEVMETHOD(bus_connect_intr,     bus_generic_connect_intr),
112
113        { 0, 0 }
114};
115
116static driver_t iicbus_driver = {
117        "iicbus",
118        iicbus_methods,
119        DRIVER_TYPE_MISC,
120        sizeof(struct iicbus_softc),
121};
122
123static int
124iicbus_probe(device_t dev)
125{
126	/* always present if probed */
127	return (0);
128}
129
130#define MAXADDR	256
131static int iicdev_found[MAXADDR];
132
133static int
134iic_probe_device(device_t dev, u_char addr)
135{
136	int count;
137	char byte;
138
139	if ((addr & 1) == 0) {
140		/* is device writable? */
141		if (!iicbus_start(dev, (u_char)addr, 0)) {
142			iicbus_stop(dev);
143			return (1);
144		}
145	} else {
146		/* is device readable? */
147		if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count))
148			return (1);
149	}
150
151	return (0);
152}
153
154/*
155 * We add all the devices which we know about.
156 * The generic attach routine will attach them if they are alive.
157 */
158static int
159iicbus_attach(device_t dev)
160{
161	struct iicbus_softc *sc = device_get_softc(dev);
162	struct iicbus_device *iicdev;
163	device_t child;
164	int addr, count;
165	char byte;
166
167	iicbus_reset(dev, IIC_FASTEST, 0, NULL);
168
169	printf("Probing for devices on iicbus%d:", device_get_unit(dev));
170
171	/* probe any devices */
172	for (addr = FIRST_SLAVE_ADDR; addr < MAXADDR; addr++) {
173		if (iic_probe_device(dev, (u_char)addr)) {
174			printf(" <%x>", addr);
175		}
176	}
177	printf("\n");
178
179	/* attach known devices */
180	for (iicdev = iicbus_children; iicdev->iicd_name; iicdev++) {
181		/* probe devices, not drivers */
182		switch (iicdev->iicd_class) {
183		case IICBUS_DEVICE_CLASS:
184			if (iic_probe_device(dev, iicdev->iicd_addr))
185				iicdev->iicd_alive = 1;
186			break;
187
188		case IICBUS_DRIVER_CLASS:
189			iicdev->iicd_alive = 1;
190			break;
191
192		default:
193			panic("%s: unknown class!", __FUNCTION__);
194		}
195
196		if (iicdev->iicd_alive) {
197			child = device_add_child(dev, iicdev->iicd_name,
198								-1, iicdev);
199			device_set_desc(child, iicdev->iicd_desc);
200		}
201	}
202	bus_generic_attach(dev);
203
204        return (0);
205}
206
207int
208iicbus_generic_intr(device_t dev, int event, char *buf)
209{
210	return (0);
211}
212
213int
214iicbus_null_callback(device_t dev, int index, caddr_t data)
215{
216	return (0);
217}
218
219int
220iicbus_null_repeated_start(device_t dev, u_char addr)
221{
222	return (IIC_ENOTSUPP);
223}
224
225static void
226iicbus_print_child(device_t bus, device_t dev)
227{
228	struct iicbus_device* iicdev = DEVTOIICBUS(dev);
229
230	switch (iicdev->iicd_class) {
231	case IICBUS_DEVICE_CLASS:
232		printf(" on %s%d addr 0x%x", device_get_name(bus),
233			device_get_unit(bus), iicdev->iicd_addr);
234		break;
235
236	case IICBUS_DRIVER_CLASS:
237		printf(" on %s%d", device_get_name(bus),
238			device_get_unit(bus));
239		break;
240
241	default:
242		panic("%s: unknown class!", __FUNCTION__);
243	}
244
245	return;
246}
247
248static int
249iicbus_read_ivar(device_t bus, device_t dev, int index, u_long* result)
250{
251	struct iicbus_device* iicdev = DEVTOIICBUS(dev);
252
253	switch (index) {
254	case IICBUS_IVAR_ADDR:
255		*result = (u_long)iicdev->iicd_addr;
256		break;
257
258	default:
259		return (ENOENT);
260	}
261
262	return (0);
263}
264
265static int
266iicbus_write_ivar(device_t bus, device_t dev, int index, u_long val)
267{
268	struct iicbus_device* iicdev = DEVTOIICBUS(dev);
269
270	switch (index) {
271	default:
272		return (ENOENT);
273	}
274
275	return (0);
276}
277
278DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0);
279DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
280DRIVER_MODULE(iicbus, bti2c, iicbus_driver, iicbus_devclass, 0, 0);
281