1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1998, 2001 Nicolas Souchu, Marc Bouget
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 *
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 /*
35 * I2C Bit-Banging over parallel port
36 *
37 * See the Official Philips interface description in lpbb(4)
38 */
39
40 #include <sys/param.h>
41 #include <sys/bus.h>
42 #include <sys/lock.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/mutex.h>
46 #include <sys/systm.h>
47 #include <sys/uio.h>
48
49
50 #include <dev/ppbus/ppbconf.h>
51 #include "ppbus_if.h"
52 #include <dev/ppbus/ppbio.h>
53
54 #include <dev/iicbus/iiconf.h>
55 #include <dev/iicbus/iicbus.h>
56
57 #include "iicbb_if.h"
58
59 static int lpbb_detect(device_t dev);
60
61 static void
lpbb_identify(driver_t * driver,device_t parent)62 lpbb_identify(driver_t *driver, device_t parent)
63 {
64
65 device_t dev;
66
67 dev = device_find_child(parent, "lpbb", -1);
68 if (!dev)
69 BUS_ADD_CHILD(parent, 0, "lpbb", -1);
70 }
71
72 static int
lpbb_probe(device_t dev)73 lpbb_probe(device_t dev)
74 {
75
76 /* Perhaps call this during identify instead? */
77 if (!lpbb_detect(dev))
78 return (ENXIO);
79
80 device_set_desc(dev, "Parallel I2C bit-banging interface");
81
82 return (0);
83 }
84
85 static int
lpbb_attach(device_t dev)86 lpbb_attach(device_t dev)
87 {
88 device_t bitbang;
89
90 /* add generic bit-banging code */
91 bitbang = device_add_child(dev, "iicbb", -1);
92 device_probe_and_attach(bitbang);
93
94 return (0);
95 }
96
97 static int
lpbb_callback(device_t dev,int index,caddr_t data)98 lpbb_callback(device_t dev, int index, caddr_t data)
99 {
100 device_t ppbus = device_get_parent(dev);
101 int error = 0;
102 int how;
103
104 switch (index) {
105 case IIC_REQUEST_BUS:
106 /* request the ppbus */
107 how = *(int *)data;
108 ppb_lock(ppbus);
109 error = ppb_request_bus(ppbus, dev, how);
110 ppb_unlock(ppbus);
111 break;
112
113 case IIC_RELEASE_BUS:
114 /* release the ppbus */
115 ppb_lock(ppbus);
116 error = ppb_release_bus(ppbus, dev);
117 ppb_unlock(ppbus);
118 break;
119
120 default:
121 error = EINVAL;
122 }
123
124 return (error);
125 }
126
127 #define SDA_out 0x80
128 #define SCL_out 0x08
129 #define SDA_in 0x80
130 #define SCL_in 0x08
131 #define ALIM 0x20
132 #define I2CKEY 0x50
133
134 /* Reset bus by setting SDA first and then SCL. */
135 static void
lpbb_reset_bus(device_t dev)136 lpbb_reset_bus(device_t dev)
137 {
138 device_t ppbus = device_get_parent(dev);
139
140 ppb_assert_locked(ppbus);
141 ppb_wdtr(ppbus, (u_char)~SDA_out);
142 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus) | SCL_out));
143 }
144
145 static int
lpbb_getscl(device_t dev)146 lpbb_getscl(device_t dev)
147 {
148 device_t ppbus = device_get_parent(dev);
149 int rval;
150
151 ppb_lock(ppbus);
152 rval = ((ppb_rstr(ppbus) & SCL_in) == SCL_in);
153 ppb_unlock(ppbus);
154 return (rval);
155 }
156
157 static int
lpbb_getsda(device_t dev)158 lpbb_getsda(device_t dev)
159 {
160 device_t ppbus = device_get_parent(dev);
161 int rval;
162
163 ppb_lock(ppbus);
164 rval = ((ppb_rstr(ppbus) & SDA_in) == SDA_in);
165 ppb_unlock(ppbus);
166 return (rval);
167 }
168
169 static void
lpbb_setsda(device_t dev,int val)170 lpbb_setsda(device_t dev, int val)
171 {
172 device_t ppbus = device_get_parent(dev);
173
174 ppb_lock(ppbus);
175 if (val == 0)
176 ppb_wdtr(ppbus, (u_char)SDA_out);
177 else
178 ppb_wdtr(ppbus, (u_char)~SDA_out);
179 ppb_unlock(ppbus);
180 }
181
182 static void
lpbb_setscl(device_t dev,int val)183 lpbb_setscl(device_t dev, int val)
184 {
185 device_t ppbus = device_get_parent(dev);
186
187 ppb_lock(ppbus);
188 if (val == 0)
189 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus) & ~SCL_out));
190 else
191 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus) | SCL_out));
192 ppb_unlock(ppbus);
193 }
194
195 static int
lpbb_detect(device_t dev)196 lpbb_detect(device_t dev)
197 {
198 device_t ppbus = device_get_parent(dev);
199
200 ppb_lock(ppbus);
201 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
202 ppb_unlock(ppbus);
203 device_printf(dev, "can't allocate ppbus\n");
204 return (0);
205 }
206
207 lpbb_reset_bus(dev);
208
209 if ((ppb_rstr(ppbus) & I2CKEY) ||
210 ((ppb_rstr(ppbus) & ALIM) != ALIM)) {
211 ppb_release_bus(ppbus, dev);
212 ppb_unlock(ppbus);
213 return (0);
214 }
215
216 ppb_release_bus(ppbus, dev);
217 ppb_unlock(ppbus);
218
219 return (1);
220 }
221
222 static int
lpbb_reset(device_t dev,u_char speed,u_char addr,u_char * oldaddr)223 lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr)
224 {
225 device_t ppbus = device_get_parent(dev);
226
227 ppb_lock(ppbus);
228 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
229 ppb_unlock(ppbus);
230 device_printf(dev, "can't allocate ppbus\n");
231 return (0);
232 }
233
234 lpbb_reset_bus(dev);
235
236 ppb_release_bus(ppbus, dev);
237 ppb_unlock(ppbus);
238
239 return (IIC_ENOADDR);
240 }
241
242 static devclass_t lpbb_devclass;
243
244 static device_method_t lpbb_methods[] = {
245 /* device interface */
246 DEVMETHOD(device_identify, lpbb_identify),
247 DEVMETHOD(device_probe, lpbb_probe),
248 DEVMETHOD(device_attach, lpbb_attach),
249
250 /* iicbb interface */
251 DEVMETHOD(iicbb_callback, lpbb_callback),
252 DEVMETHOD(iicbb_setsda, lpbb_setsda),
253 DEVMETHOD(iicbb_setscl, lpbb_setscl),
254 DEVMETHOD(iicbb_getsda, lpbb_getsda),
255 DEVMETHOD(iicbb_getscl, lpbb_getscl),
256 DEVMETHOD(iicbb_reset, lpbb_reset),
257
258 DEVMETHOD_END
259 };
260
261 static driver_t lpbb_driver = {
262 "lpbb",
263 lpbb_methods,
264 1,
265 };
266
267 DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0);
268 DRIVER_MODULE(iicbb, lpbb, iicbb_driver, iicbb_devclass, 0, 0);
269 MODULE_DEPEND(lpbb, ppbus, 1, 1, 1);
270 MODULE_DEPEND(lpbb, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER);
271 MODULE_VERSION(lpbb, 1);
272