iiconf.c revision 160372 
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 160372 2006-07-14 23:15:06Z imp $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/module.h>
33#include <sys/bus.h>
34
35#include <dev/iicbus/iiconf.h>
36#include <dev/iicbus/iicbus.h>
37#include "iicbus_if.h"
38
39/*
40 * iicbus_intr()
41 */
42void
43iicbus_intr(device_t bus, int event, char *buf)
44{
45	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
46
47	/* call owner's intr routine */
48	if (sc->owner)
49		IICBUS_INTR(sc->owner, event, buf);
50
51	return;
52}
53
54static int
55iicbus_poll(struct iicbus_softc *sc, int how)
56{
57	int error;
58
59	switch (how) {
60	case (IIC_WAIT | IIC_INTR):
61		error = tsleep(sc, IICPRI|PCATCH, "iicreq", 0);
62		break;
63
64	case (IIC_WAIT | IIC_NOINTR):
65		error = tsleep(sc, IICPRI, "iicreq", 0);
66		break;
67
68	default:
69		return (EWOULDBLOCK);
70		break;
71	}
72
73	return (error);
74}
75
76/*
77 * iicbus_request_bus()
78 *
79 * Allocate the device to perform transfers.
80 *
81 * how	: IIC_WAIT or IIC_DONTWAIT
82 */
83int
84iicbus_request_bus(device_t bus, device_t dev, int how)
85{
86	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
87	int s, error = 0;
88
89	/* first, ask the underlying layers if the request is ok */
90	do {
91		error = IICBUS_CALLBACK(device_get_parent(bus),
92						IIC_REQUEST_BUS, (caddr_t)&how);
93		if (error)
94			error = iicbus_poll(sc, how);
95	} while (error == EWOULDBLOCK);
96
97	while (!error) {
98		s = splhigh();
99		if (sc->owner && sc->owner != dev) {
100			splx(s);
101
102			error = iicbus_poll(sc, how);
103		} else {
104			sc->owner = dev;
105
106			splx(s);
107			return (0);
108		}
109
110		/* free any allocated resource */
111		if (error)
112			IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS,
113					(caddr_t)&how);
114	}
115
116	return (error);
117}
118
119/*
120 * iicbus_release_bus()
121 *
122 * Release the device allocated with iicbus_request_dev()
123 */
124int
125iicbus_release_bus(device_t bus, device_t dev)
126{
127	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
128	int s, error;
129
130	/* first, ask the underlying layers if the release is ok */
131	error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
132
133	if (error)
134		return (error);
135
136	s = splhigh();
137	if (sc->owner != dev) {
138		splx(s);
139		return (EACCES);
140	}
141
142	sc->owner = 0;
143	splx(s);
144
145	/* wakeup waiting processes */
146	wakeup(sc);
147
148	return (0);
149}
150
151/*
152 * iicbus_started()
153 *
154 * Test if the iicbus is started by the controller
155 */
156int
157iicbus_started(device_t bus)
158{
159	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
160
161	return (sc->started);
162}
163
164/*
165 * iicbus_start()
166 *
167 * Send start condition to the slave addressed by 'slave'
168 */
169int
170iicbus_start(device_t bus, u_char slave, int timeout)
171{
172	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
173	int error = 0;
174
175	if (sc->started)
176		return (EINVAL);		/* bus already started */
177
178	if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
179		sc->started = slave;
180	else
181		sc->started = 0;
182
183	return (error);
184}
185
186/*
187 * iicbus_repeated_start()
188 *
189 * Send start condition to the slave addressed by 'slave'
190 */
191int
192iicbus_repeated_start(device_t bus, u_char slave, int timeout)
193{
194	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
195	int error = 0;
196
197	if (!sc->started)
198		return (EINVAL);     /* bus should have been already started */
199
200	if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
201		sc->started = slave;
202	else
203		sc->started = 0;
204
205	return (error);
206}
207
208/*
209 * iicbus_stop()
210 *
211 * Send stop condition to the bus
212 */
213int
214iicbus_stop(device_t bus)
215{
216	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
217	int error = 0;
218
219	if (!sc->started)
220		return (EINVAL);		/* bus not started */
221
222	error = IICBUS_STOP(device_get_parent(bus));
223
224	/* refuse any further access */
225	sc->started = 0;
226
227	return (error);
228}
229
230/*
231 * iicbus_write()
232 *
233 * Write a block of data to the slave previously started by
234 * iicbus_start() call
235 */
236int
237iicbus_write(device_t bus, char *buf, int len, int *sent, int timeout)
238{
239	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
240
241	/* a slave must have been started with the appropriate address */
242	if (!sc->started || (sc->started & LSB))
243		return (EINVAL);
244
245	return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
246}
247
248/*
249 * iicbus_read()
250 *
251 * Read a block of data from the slave previously started by
252 * iicbus_read() call
253 */
254int
255iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
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_READ(device_get_parent(bus), buf, len, read, last, delay));
264}
265
266/*
267 * iicbus_write_byte()
268 *
269 * Write a byte to the slave previously started by iicbus_start() call
270 */
271int
272iicbus_write_byte(device_t bus, char byte, int timeout)
273{
274	char data = byte;
275	int sent;
276
277	return (iicbus_write(bus, &data, 1, &sent, timeout));
278}
279
280/*
281 * iicbus_read_byte()
282 *
283 * Read a byte from the slave previously started by iicbus_start() call
284 */
285int
286iicbus_read_byte(device_t bus, char *byte, int timeout)
287{
288	int read;
289
290	return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
291}
292
293/*
294 * iicbus_block_write()
295 *
296 * Write a block of data to slave ; start/stop protocol managed
297 */
298int
299iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
300{
301	u_char addr = slave & ~LSB;
302	int error;
303
304	if ((error = iicbus_start(bus, addr, 0)))
305		return (error);
306
307	error = iicbus_write(bus, buf, len, sent, 0);
308
309	iicbus_stop(bus);
310
311	return (error);
312}
313
314/*
315 * iicbus_block_read()
316 *
317 * Read a block of data from slave ; start/stop protocol managed
318 */
319int
320iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
321{
322	u_char addr = slave | LSB;
323	int error;
324
325	if ((error = iicbus_start(bus, addr, 0)))
326		return (error);
327
328	error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
329
330	iicbus_stop(bus);
331
332	return (error);
333}
334
335/*
336 * iicbus_trasnfer()
337 *
338 * Do an aribtrary number of transfers on the iicbus.  We pass these
339 * raw requests to the bridge driver.  If the bridge driver supports
340 * them directly, then it manages all the details.  If not, it can use
341 * the helper function iicbus_transfer_gen() which will do the
342 * transfers at a low level.
343 *
344 * Pointers passed in as part of iic_msg must be kernel pointers.
345 * Callers that have user addresses to manage must do so on their own.
346 */
347int
348iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
349{
350	return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
351}
352
353/*
354 * Generic version of iicbus_transfer that calls the appropriate
355 * routines to accomplish this.  See note above about acceptable
356 * buffer addresses.
357 */
358int
359iicbus_transfer_gen(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
360{
361	int i, error, max, lenread, lenwrote;
362
363	for (i = 0, max = 0; i < nmsgs; i++)
364		if (max < msgs[i].len)
365			max = msgs[i].len;
366	for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
367		if (msgs[i].flags & IIC_M_RD)
368			error = iicbus_block_read(bus, msgs[i].slave,
369			    msgs[i].buf, msgs[i].len, &lenread);
370		else
371			error = iicbus_block_write(bus, msgs[i].slave,
372			    msgs[i].buf, msgs[i].len, &lenwrote);
373	}
374	return (error);
375}
376