FreeBSD/Linux Kernel Cross Reference
sys/dev/ppbus/lpbb.c
1 /*-
2 * Copyright (c) 1998, 2001 Nicolas Souchu, Marc Bouget
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 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: releng/6.4/sys/dev/ppbus/lpbb.c 160503 2006-07-19 16:31:12Z kib $");
31
32 /*
33 * I2C Bit-Banging over parallel port
34 *
35 * See the Official Philips interface description in lpbb(4)
36 */
37
38 #include <sys/param.h>
39 #include <sys/kernel.h>
40 #include <sys/systm.h>
41 #include <sys/module.h>
42 #include <sys/bus.h>
43 #include <sys/uio.h>
44
45
46 #include <dev/ppbus/ppbconf.h>
47 #include "ppbus_if.h"
48 #include <dev/ppbus/ppbio.h>
49
50 #include <dev/iicbus/iiconf.h>
51 #include <dev/iicbus/iicbus.h>
52
53 #include "iicbb_if.h"
54
55 static int lpbb_detect(device_t dev);
56
57 static void
58 lpbb_identify(driver_t *driver, device_t parent)
59 {
60
61 device_t dev;
62
63 dev = device_find_child(parent, "lpbb", 0);
64 if (!dev)
65 BUS_ADD_CHILD(parent, 0, "lpbb", -1);
66 }
67
68 static int
69 lpbb_probe(device_t dev)
70 {
71
72 /* Perhaps call this during identify instead? */
73 if (!lpbb_detect(dev))
74 return (ENXIO);
75
76 device_set_desc(dev, "Parallel I2C bit-banging interface");
77
78 return (0);
79 }
80
81 static int
82 lpbb_attach(device_t dev)
83 {
84 device_t bitbang;
85
86 /* add generic bit-banging code */
87 bitbang = device_add_child(dev, "iicbb", -1);
88 device_probe_and_attach(bitbang);
89
90 return (0);
91 }
92
93 static int
94 lpbb_callback(device_t dev, int index, caddr_t *data)
95 {
96 device_t ppbus = device_get_parent(dev);
97 int error = 0;
98 int how;
99
100 switch (index) {
101 case IIC_REQUEST_BUS:
102 /* request the ppbus */
103 how = *(int *)data;
104 error = ppb_request_bus(ppbus, dev, how);
105 break;
106
107 case IIC_RELEASE_BUS:
108 /* release the ppbus */
109 error = ppb_release_bus(ppbus, dev);
110 break;
111
112 default:
113 error = EINVAL;
114 }
115
116 return (error);
117 }
118
119 #define SDA_out 0x80
120 #define SCL_out 0x08
121 #define SDA_in 0x80
122 #define SCL_in 0x08
123 #define ALIM 0x20
124 #define I2CKEY 0x50
125
126 static int lpbb_getscl(device_t dev)
127 {
128 return ((ppb_rstr(device_get_parent(dev)) & SCL_in) == SCL_in);
129 }
130
131 static int lpbb_getsda(device_t dev)
132 {
133 return ((ppb_rstr(device_get_parent(dev)) & SDA_in) == SDA_in);
134 }
135
136 static void lpbb_setsda(device_t dev, char val)
137 {
138 device_t ppbus = device_get_parent(dev);
139
140 if(val==0)
141 ppb_wdtr(ppbus, (u_char)SDA_out);
142 else
143 ppb_wdtr(ppbus, (u_char)~SDA_out);
144 }
145
146 static void lpbb_setscl(device_t dev, unsigned char val)
147 {
148 device_t ppbus = device_get_parent(dev);
149
150 if(val==0)
151 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)&~SCL_out));
152 else
153 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)|SCL_out));
154 }
155
156 static int lpbb_detect(device_t dev)
157 {
158 device_t ppbus = device_get_parent(dev);
159
160 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
161 device_printf(dev, "can't allocate ppbus\n");
162 return (0);
163 }
164
165 /* reset bus */
166 lpbb_setsda(dev, 1);
167 lpbb_setscl(dev, 1);
168
169 if ((ppb_rstr(ppbus) & I2CKEY) ||
170 ((ppb_rstr(ppbus) & ALIM) != ALIM)) {
171
172 ppb_release_bus(ppbus, dev);
173 return (0);
174 }
175
176 ppb_release_bus(ppbus, dev);
177
178 return (1);
179 }
180
181 static int
182 lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr)
183 {
184 device_t ppbus = device_get_parent(dev);
185
186 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
187 device_printf(dev, "can't allocate ppbus\n");
188 return (0);
189 }
190
191 /* reset bus */
192 lpbb_setsda(dev, 1);
193 lpbb_setscl(dev, 1);
194
195 ppb_release_bus(ppbus, dev);
196
197 return (IIC_ENOADDR);
198 }
199
200 static devclass_t lpbb_devclass;
201
202 static device_method_t lpbb_methods[] = {
203 /* device interface */
204 DEVMETHOD(device_identify, lpbb_identify),
205 DEVMETHOD(device_probe, lpbb_probe),
206 DEVMETHOD(device_attach, lpbb_attach),
207
208 /* bus interface */
209 DEVMETHOD(bus_print_child, bus_generic_print_child),
210
211 /* iicbb interface */
212 DEVMETHOD(iicbb_callback, lpbb_callback),
213 DEVMETHOD(iicbb_setsda, lpbb_setsda),
214 DEVMETHOD(iicbb_setscl, lpbb_setscl),
215 DEVMETHOD(iicbb_getsda, lpbb_getsda),
216 DEVMETHOD(iicbb_getscl, lpbb_getscl),
217 DEVMETHOD(iicbb_reset, lpbb_reset),
218
219 { 0, 0 }
220 };
221
222 static driver_t lpbb_driver = {
223 "lpbb",
224 lpbb_methods,
225 1,
226 };
227
228 DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0);
229 MODULE_DEPEND(lpbb, ppbus, 1, 1, 1);
230 MODULE_DEPEND(lpbb, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER);
231 MODULE_VERSION(lpbb, 1);
Cache object: 890e197332e5c95768e7032beb62d736
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