iiconf.c revision 167855 
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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/dev/iicbus/iiconf.c 167855 2007-03-23 23:03:54Z imp $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/malloc.h>
33#include <sys/module.h>
34#include <sys/bus.h>
35
36#include <dev/iicbus/iiconf.h>
37#include <dev/iicbus/iicbus.h>
38#include "iicbus_if.h"
39
40/*
41 * iicbus_intr()
42 */
43void
44iicbus_intr(device_t bus, int event, char *buf)
45{
46	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
47
48	/* call owner's intr routine */
49	if (sc->owner)
50		IICBUS_INTR(sc->owner, event, buf);
51
52	return;
53}
54
55static int
56iicbus_poll(struct iicbus_softc *sc, int how)
57{
58	int error;
59
60	switch (how) {
61	case (IIC_WAIT | IIC_INTR):
62		error = tsleep(sc, IICPRI|PCATCH, "iicreq", 0);
63		break;
64
65	case (IIC_WAIT | IIC_NOINTR):
66		error = tsleep(sc, IICPRI, "iicreq", 0);
67		break;
68
69	default:
70		return (EWOULDBLOCK);
71		break;
72	}
73
74	return (error);
75}
76
77/*
78 * iicbus_request_bus()
79 *
80 * Allocate the device to perform transfers.
81 *
82 * how	: IIC_WAIT or IIC_DONTWAIT
83 */
84int
85iicbus_request_bus(device_t bus, device_t dev, int how)
86{
87	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
88	int s, error = 0;
89
90	/* first, ask the underlying layers if the request is ok */
91	do {
92		error = IICBUS_CALLBACK(device_get_parent(bus),
93						IIC_REQUEST_BUS, (caddr_t)&how);
94		if (error)
95			error = iicbus_poll(sc, how);
96	} while (error == EWOULDBLOCK);
97
98	while (!error) {
99		s = splhigh();
100		if (sc->owner && sc->owner != dev) {
101			splx(s);
102
103			error = iicbus_poll(sc, how);
104		} else {
105			sc->owner = dev;
106
107			splx(s);
108			return (0);
109		}
110
111		/* free any allocated resource */
112		if (error)
113			IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS,
114					(caddr_t)&how);
115	}
116
117	return (error);
118}
119
120/*
121 * iicbus_release_bus()
122 *
123 * Release the device allocated with iicbus_request_dev()
124 */
125int
126iicbus_release_bus(device_t bus, device_t dev)
127{
128	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
129	int s, error;
130
131	/* first, ask the underlying layers if the release is ok */
132	error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
133
134	if (error)
135		return (error);
136
137	s = splhigh();
138	if (sc->owner != dev) {
139		splx(s);
140		return (EACCES);
141	}
142
143	sc->owner = 0;
144	splx(s);
145
146	/* wakeup waiting processes */
147	wakeup(sc);
148
149	return (0);
150}
151
152/*
153 * iicbus_started()
154 *
155 * Test if the iicbus is started by the controller
156 */
157int
158iicbus_started(device_t bus)
159{
160	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
161
162	return (sc->started);
163}
164
165/*
166 * iicbus_start()
167 *
168 * Send start condition to the slave addressed by 'slave'
169 */
170int
171iicbus_start(device_t bus, u_char slave, int timeout)
172{
173	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
174	int error = 0;
175
176	if (sc->started)
177		return (EINVAL);		/* bus already started */
178
179	if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
180		sc->started = slave;
181	else
182		sc->started = 0;
183
184	return (error);
185}
186
187/*
188 * iicbus_repeated_start()
189 *
190 * Send start condition to the slave addressed by 'slave'
191 */
192int
193iicbus_repeated_start(device_t bus, u_char slave, int timeout)
194{
195	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
196	int error = 0;
197
198	if (!sc->started)
199		return (EINVAL);     /* bus should have been already started */
200
201	if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
202		sc->started = slave;
203	else
204		sc->started = 0;
205
206	return (error);
207}
208
209/*
210 * iicbus_stop()
211 *
212 * Send stop condition to the bus
213 */
214int
215iicbus_stop(device_t bus)
216{
217	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
218	int error = 0;
219
220	if (!sc->started)
221		return (EINVAL);		/* bus not started */
222
223	error = IICBUS_STOP(device_get_parent(bus));
224
225	/* refuse any further access */
226	sc->started = 0;
227
228	return (error);
229}
230
231/*
232 * iicbus_write()
233 *
234 * Write a block of data to the slave previously started by
235 * iicbus_start() call
236 */
237int
238iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
239{
240	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
241
242	/* a slave must have been started with the appropriate address */
243	if (!sc->started || (sc->started & LSB))
244		return (EINVAL);
245
246	return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
247}
248
249/*
250 * iicbus_read()
251 *
252 * Read a block of data from the slave previously started by
253 * iicbus_read() call
254 */
255int
256iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
257{
258	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
259
260	/* a slave must have been started with the appropriate address */
261	if (!sc->started || !(sc->started & LSB))
262		return (EINVAL);
263
264	return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
265}
266
267/*
268 * iicbus_write_byte()
269 *
270 * Write a byte to the slave previously started by iicbus_start() call
271 */
272int
273iicbus_write_byte(device_t bus, char byte, int timeout)
274{
275	char data = byte;
276	int sent;
277
278	return (iicbus_write(bus, &data, 1, &sent, timeout));
279}
280
281/*
282 * iicbus_read_byte()
283 *
284 * Read a byte from the slave previously started by iicbus_start() call
285 */
286int
287iicbus_read_byte(device_t bus, char *byte, int timeout)
288{
289	int read;
290
291	return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
292}
293
294/*
295 * iicbus_block_write()
296 *
297 * Write a block of data to slave ; start/stop protocol managed
298 */
299int
300iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
301{
302	u_char addr = slave & ~LSB;
303	int error;
304
305	if ((error = iicbus_start(bus, addr, 0)))
306		return (error);
307
308	error = iicbus_write(bus, buf, len, sent, 0);
309
310	iicbus_stop(bus);
311
312	return (error);
313}
314
315/*
316 * iicbus_block_read()
317 *
318 * Read a block of data from slave ; start/stop protocol managed
319 */
320int
321iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
322{
323	u_char addr = slave | LSB;
324	int error;
325
326	if ((error = iicbus_start(bus, addr, 0)))
327		return (error);
328
329	error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
330
331	iicbus_stop(bus);
332
333	return (error);
334}
335
336/*
337 * iicbus_trasnfer()
338 *
339 * Do an aribtrary number of transfers on the iicbus.  We pass these
340 * raw requests to the bridge driver.  If the bridge driver supports
341 * them directly, then it manages all the details.  If not, it can use
342 * the helper function iicbus_transfer_gen() which will do the
343 * transfers at a low level.
344 *
345 * Pointers passed in as part of iic_msg must be kernel pointers.
346 * Callers that have user addresses to manage must do so on their own.
347 */
348int
349iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
350{
351	return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
352}
353
354/*
355 * Generic version of iicbus_transfer that calls the appropriate
356 * routines to accomplish this.  See note above about acceptable
357 * buffer addresses.
358 */
359int
360iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
361{
362	int i, error, lenread, lenwrote, nkid;
363	device_t *children, bus;
364
365	device_get_children(dev, &children, &nkid);
366	if (nkid != 1)
367		return EIO;
368	bus = children[0];
369	free(children, M_TEMP);
370	for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
371		if (msgs[i].flags & IIC_M_RD)
372			error = iicbus_block_read(bus, msgs[i].slave,
373			    msgs[i].buf, msgs[i].len, &lenread);
374		else
375			error = iicbus_block_write(bus, msgs[i].slave,
376			    msgs[i].buf, msgs[i].len, &lenwrote);
377	}
378	return (error);
379}
380