xref: /freebsd/sys/dev/iicbus/iicbus.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
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("$FreeBSD$");
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 
49 static int
50 iicbus_probe(device_t dev)
51 {
52 
53 	device_set_desc(dev, "Philips I2C bus");
54 	return (0);
55 }
56 
57 #if SCAN_IICBUS
58 static int
59 iic_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  */
84 static int
85 iicbus_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 
122 static int
123 iicbus_detach(device_t dev)
124 {
125 
126 	iicbus_reset(dev, IIC_FASTEST, 0, NULL);
127 	bus_generic_detach(dev);
128 	return (0);
129 }
130 
131 static int
132 iicbus_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 
145 static void
146 iicbus_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 
155 static int
156 iicbus_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 
165 static int
166 iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
167     size_t buflen)
168 {
169 	*buf = '\0';
170 	return (0);
171 }
172 
173 static int
174 iicbus_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 
188 static device_t
189 iicbus_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 
206 static void
207 iicbus_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 
217 int
218 iicbus_generic_intr(device_t dev, int event, char *buf)
219 {
220 
221 	return (0);
222 }
223 
224 int
225 iicbus_null_callback(device_t dev, int index, caddr_t data)
226 {
227 
228 	return (0);
229 }
230 
231 int
232 iicbus_null_repeated_start(device_t dev, u_char addr)
233 {
234 
235 	return (IIC_ENOTSUPP);
236 }
237 
238 static 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 
260 driver_t iicbus_driver = {
261         "iicbus",
262         iicbus_methods,
263         sizeof(struct iicbus_softc),
264 };
265 
266 devclass_t iicbus_devclass;
267 
268 DRIVER_MODULE(iicbus, envctrl, iicbus_driver, iicbus_devclass, 0, 0);
269 DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
270 MODULE_VERSION(iicbus, IICBUS_MODVER);
271