Additional note to last commit. GCC-3.4 improperly generates a warning
[dragonfly.git] / sys / bus / iicbus / iiconf.c
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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 * $FreeBSD: src/sys/dev/iicbus/iiconf.c,v 1.10 1999/12/03 08:41:02 mdodd Exp $
1f2de5d4 27 * $DragonFly: src/sys/bus/iicbus/iiconf.c,v 1.4 2003/08/07 21:16:45 dillon Exp $
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28 *
29 */
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/malloc.h>
34#include <sys/module.h>
35#include <sys/bus.h>
36
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37#include "iiconf.h"
38#include "iicbus.h"
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39#include "iicbus_if.h"
40
41/*
42 * iicbus_intr()
43 */
44void
45iicbus_intr(device_t bus, int event, char *buf)
46{
47 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
48
49 /* call owner's intr routine */
50 if (sc->owner)
51 IICBUS_INTR(sc->owner, event, buf);
52
53 return;
54}
55
56/*
57 * iicbus_alloc_bus()
58 *
59 * Allocate a new bus connected to the given parent device
60 */
61device_t
62iicbus_alloc_bus(device_t parent)
63{
64 device_t child;
65
66 /* add the bus to the parent */
67 child = device_add_child(parent, "iicbus", -1);
68
69 return (child);
70}
71
72static int
73iicbus_poll(struct iicbus_softc *sc, int how)
74{
75 int error;
76
77 switch (how) {
78 case (IIC_WAIT | IIC_INTR):
377d4740 79 error = tsleep(sc, PCATCH, "iicreq", 0);
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80 break;
81
82 case (IIC_WAIT | IIC_NOINTR):
377d4740 83 error = tsleep(sc, 0, "iicreq", 0);
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84 break;
85
86 default:
87 return (EWOULDBLOCK);
88 break;
89 }
90
91 return (error);
92}
93
94/*
95 * iicbus_request_bus()
96 *
97 * Allocate the device to perform transfers.
98 *
99 * how : IIC_WAIT or IIC_DONTWAIT
100 */
101int
102iicbus_request_bus(device_t bus, device_t dev, int how)
103{
104 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
105 int s, error = 0;
106
107 /* first, ask the underlying layers if the request is ok */
108 do {
109 error = IICBUS_CALLBACK(device_get_parent(bus),
110 IIC_REQUEST_BUS, (caddr_t)&how);
111 if (error)
112 error = iicbus_poll(sc, how);
113 } while (error == EWOULDBLOCK);
114
115 while (!error) {
116 s = splhigh();
117 if (sc->owner && sc->owner != dev) {
118 splx(s);
119
120 error = iicbus_poll(sc, how);
121 } else {
122 sc->owner = dev;
123
124 splx(s);
125 return (0);
126 }
127
128 /* free any allocated resource */
129 if (error)
130 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS,
131 (caddr_t)&how);
132 }
133
134 return (error);
135}
136
137/*
138 * iicbus_release_bus()
139 *
140 * Release the device allocated with iicbus_request_dev()
141 */
142int
143iicbus_release_bus(device_t bus, device_t dev)
144{
145 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
146 int s, error;
147
148 /* first, ask the underlying layers if the release is ok */
149 error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
150
151 if (error)
152 return (error);
153
154 s = splhigh();
155 if (sc->owner != dev) {
156 splx(s);
157 return (EACCES);
158 }
159
160 sc->owner = 0;
161 splx(s);
162
163 /* wakeup waiting processes */
164 wakeup(sc);
165
166 return (0);
167}
168
169/*
170 * iicbus_started()
171 *
172 * Test if the iicbus is started by the controller
173 */
174int
175iicbus_started(device_t bus)
176{
177 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
178
179 return (sc->started);
180}
181
182/*
183 * iicbus_start()
184 *
185 * Send start condition to the slave addressed by 'slave'
186 */
187int
188iicbus_start(device_t bus, u_char slave, int timeout)
189{
190 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
191 int error = 0;
192
193 if (sc->started)
194 return (EINVAL); /* bus already started */
195
196 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
197 sc->started = slave;
198 else
199 sc->started = 0;
200
201 return (error);
202}
203
204/*
205 * iicbus_repeated_start()
206 *
207 * Send start condition to the slave addressed by 'slave'
208 */
209int
210iicbus_repeated_start(device_t bus, u_char slave, int timeout)
211{
212 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
213 int error = 0;
214
215 if (!sc->started)
216 return (EINVAL); /* bus should have been already started */
217
218 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
219 sc->started = slave;
220 else
221 sc->started = 0;
222
223 return (error);
224}
225
226/*
227 * iicbus_stop()
228 *
229 * Send stop condition to the bus
230 */
231int
232iicbus_stop(device_t bus)
233{
234 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
235 int error = 0;
236
237 if (!sc->started)
238 return (EINVAL); /* bus not started */
239
240 error = IICBUS_STOP(device_get_parent(bus));
241
242 /* refuse any further access */
243 sc->started = 0;
244
245 return (error);
246}
247
248/*
249 * iicbus_write()
250 *
251 * Write a block of data to the slave previously started by
252 * iicbus_start() call
253 */
254int
255iicbus_write(device_t bus, char *buf, int len, int *sent, int timeout)
256{
257 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
258
259 /* a slave must have been started with the appropriate address */
260 if (!sc->started || (sc->started & LSB))
261 return (EINVAL);
262
263 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
264}
265
266/*
267 * iicbus_read()
268 *
269 * Read a block of data from the slave previously started by
270 * iicbus_read() call
271 */
272int
273iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
274{
275 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
276
277 /* a slave must have been started with the appropriate address */
278 if (!sc->started || !(sc->started & LSB))
279 return (EINVAL);
280
281 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
282}
283
284/*
285 * iicbus_write_byte()
286 *
287 * Write a byte to the slave previously started by iicbus_start() call
288 */
289int
290iicbus_write_byte(device_t bus, char byte, int timeout)
291{
292 char data = byte;
293 int sent;
294
295 return (iicbus_write(bus, &data, 1, &sent, timeout));
296}
297
298/*
299 * iicbus_read_byte()
300 *
301 * Read a byte from the slave previously started by iicbus_start() call
302 */
303int
304iicbus_read_byte(device_t bus, char *byte, int timeout)
305{
306 int read;
307
308 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
309}
310
311/*
312 * iicbus_block_write()
313 *
314 * Write a block of data to slave ; start/stop protocol managed
315 */
316int
317iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
318{
319 u_char addr = slave & ~LSB;
320 int error;
321
322 if ((error = iicbus_start(bus, addr, 0)))
323 return (error);
324
325 error = iicbus_write(bus, buf, len, sent, 0);
326
327 iicbus_stop(bus);
328
329 return (error);
330}
331
332/*
333 * iicbus_block_read()
334 *
335 * Read a block of data from slave ; start/stop protocol managed
336 */
337int
338iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
339{
340 u_char addr = slave | LSB;
341 int error;
342
343 if ((error = iicbus_start(bus, addr, 0)))
344 return (error);
345
346 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
347
348 iicbus_stop(bus);
349
350 return (error);
351}
352
353/*
354 * iicbus_get_addr()
355 *
356 * Get the I2C 7 bits address of the device
357 */
358u_char
359iicbus_get_addr(device_t dev)
360{
361 uintptr_t addr;
362 device_t parent = device_get_parent(dev);
363
364 BUS_READ_IVAR(parent, dev, IICBUS_IVAR_ADDR, &addr);
365
366 return ((u_char)addr);
367}
368