iicsmb.c revision 162234 
1/*-
2 * Copyright (c) 1998, 2001 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: head/sys/dev/iicbus/iicsmb.c 162234 2006-09-11 20:52:41Z jhb $
27 *
28 */
29
30/*
31 * I2C to SMB bridge
32 *
33 * Example:
34 *
35 *     smb bttv
36 *       \ /
37 *      smbus
38 *       /  \
39 *    iicsmb bti2c
40 *       |
41 *     iicbus
42 *     /  |  \
43 *  iicbb pcf ...
44 *    |
45 *  lpbb
46 */
47
48#include <sys/param.h>
49#include <sys/kernel.h>
50#include <sys/systm.h>
51#include <sys/module.h>
52#include <sys/bus.h>
53#include <sys/uio.h>
54
55
56#include <dev/iicbus/iiconf.h>
57#include <dev/iicbus/iicbus.h>
58
59#include <dev/smbus/smbconf.h>
60
61#include "iicbus_if.h"
62#include "smbus_if.h"
63
64struct iicsmb_softc {
65
66#define SMB_WAITING_ADDR	0x0
67#define SMB_WAITING_LOW		0x1
68#define SMB_WAITING_HIGH	0x2
69#define SMB_DONE		0x3
70	int state;
71
72	u_char devaddr;			/* slave device address */
73
74	char low;			/* low byte received first */
75	char high;			/* high byte */
76
77	device_t smbus;
78};
79
80static int iicsmb_probe(device_t);
81static int iicsmb_attach(device_t);
82static int iicsmb_detach(device_t);
83static void iicsmb_identify(driver_t *driver, device_t parent);
84
85static void iicsmb_intr(device_t dev, int event, char *buf);
86static int iicsmb_callback(device_t dev, int index, void *data);
87static int iicsmb_quick(device_t dev, u_char slave, int how);
88static int iicsmb_sendb(device_t dev, u_char slave, char byte);
89static int iicsmb_recvb(device_t dev, u_char slave, char *byte);
90static int iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte);
91static int iicsmb_writew(device_t dev, u_char slave, char cmd, short word);
92static int iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte);
93static int iicsmb_readw(device_t dev, u_char slave, char cmd, short *word);
94static int iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata);
95static int iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf);
96static int iicsmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf);
97
98static devclass_t iicsmb_devclass;
99
100static device_method_t iicsmb_methods[] = {
101	/* device interface */
102	DEVMETHOD(device_identify,	iicsmb_identify),
103	DEVMETHOD(device_probe,		iicsmb_probe),
104	DEVMETHOD(device_attach,	iicsmb_attach),
105	DEVMETHOD(device_detach,	iicsmb_detach),
106
107	/* bus interface */
108	DEVMETHOD(bus_driver_added,	bus_generic_driver_added),
109	DEVMETHOD(bus_print_child,	bus_generic_print_child),
110
111	/* iicbus interface */
112	DEVMETHOD(iicbus_intr,		iicsmb_intr),
113
114	/* smbus interface */
115	DEVMETHOD(smbus_callback,	iicsmb_callback),
116	DEVMETHOD(smbus_quick,		iicsmb_quick),
117	DEVMETHOD(smbus_sendb,		iicsmb_sendb),
118	DEVMETHOD(smbus_recvb,		iicsmb_recvb),
119	DEVMETHOD(smbus_writeb,		iicsmb_writeb),
120	DEVMETHOD(smbus_writew,		iicsmb_writew),
121	DEVMETHOD(smbus_readb,		iicsmb_readb),
122	DEVMETHOD(smbus_readw,		iicsmb_readw),
123	DEVMETHOD(smbus_pcall,		iicsmb_pcall),
124	DEVMETHOD(smbus_bwrite,		iicsmb_bwrite),
125	DEVMETHOD(smbus_bread,		iicsmb_bread),
126
127	{ 0, 0 }
128};
129
130static driver_t iicsmb_driver = {
131	"iicsmb",
132	iicsmb_methods,
133	sizeof(struct iicsmb_softc),
134};
135
136#define IICBUS_TIMEOUT	100	/* us */
137
138static void
139iicsmb_identify(driver_t *driver, device_t parent)
140{
141	BUS_ADD_CHILD(parent, 0, "iicsmb", -1);
142}
143
144static int
145iicsmb_probe(device_t dev)
146{
147	device_set_desc(dev, "SMBus over I2C bridge");
148	return (0);
149}
150
151static int
152iicsmb_attach(device_t dev)
153{
154	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
155
156	sc->smbus = device_add_child(dev, "smbus", -1);
157
158	/* probe and attach the smbus */
159	bus_generic_attach(dev);
160
161	return (0);
162}
163
164static int
165iicsmb_detach(device_t dev)
166{
167	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
168
169	bus_generic_detach(dev);
170	if (sc->smbus) {
171		device_delete_child(dev, sc->smbus);
172	}
173
174	return (0);
175}
176
177/*
178 * iicsmb_intr()
179 *
180 * iicbus interrupt handler
181 */
182static void
183iicsmb_intr(device_t dev, int event, char *buf)
184{
185	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
186
187	switch (event) {
188	case INTR_GENERAL:
189	case INTR_START:
190		sc->state = SMB_WAITING_ADDR;
191		break;
192
193	case INTR_STOP:
194		/* call smbus intr handler */
195		smbus_intr(sc->smbus, sc->devaddr,
196				sc->low, sc->high, SMB_ENOERR);
197		break;
198
199	case INTR_RECEIVE:
200		switch (sc->state) {
201		case SMB_DONE:
202			/* XXX too much data, discard */
203			printf("%s: too much data from 0x%x\n", __func__,
204				sc->devaddr & 0xff);
205			goto end;
206
207		case SMB_WAITING_ADDR:
208			sc->devaddr = (u_char)*buf;
209			sc->state = SMB_WAITING_LOW;
210			break;
211
212		case SMB_WAITING_LOW:
213			sc->low = *buf;
214			sc->state = SMB_WAITING_HIGH;
215			break;
216
217		case SMB_WAITING_HIGH:
218			sc->high = *buf;
219			sc->state = SMB_DONE;
220			break;
221		}
222end:
223		break;
224
225	case INTR_TRANSMIT:
226	case INTR_NOACK:
227		break;
228
229	case INTR_ERROR:
230		switch (*buf) {
231		case IIC_EBUSERR:
232			smbus_intr(sc->smbus, sc->devaddr, 0, 0, SMB_EBUSERR);
233			break;
234
235		default:
236			printf("%s unknown error 0x%x!\n", __func__,
237								(int)*buf);
238			break;
239		}
240		break;
241
242	default:
243		panic("%s: unknown event (%d)!", __func__, event);
244	}
245
246	return;
247}
248
249static int
250iicsmb_callback(device_t dev, int index, void *data)
251{
252	device_t parent = device_get_parent(dev);
253	int error = 0;
254	int how;
255
256	switch (index) {
257	case SMB_REQUEST_BUS:
258		/* request underlying iicbus */
259		how = *(int *)data;
260		error = iicbus_request_bus(parent, dev, how);
261		break;
262
263	case SMB_RELEASE_BUS:
264		/* release underlying iicbus */
265		error = iicbus_release_bus(parent, dev);
266		break;
267
268	default:
269		error = EINVAL;
270	}
271
272	return (error);
273}
274
275static int
276iicsmb_quick(device_t dev, u_char slave, int how)
277{
278	device_t parent = device_get_parent(dev);
279	int error;
280
281	switch (how) {
282	case SMB_QWRITE:
283		error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT);
284		break;
285
286	case SMB_QREAD:
287		error = iicbus_start(parent, slave | LSB, IICBUS_TIMEOUT);
288		break;
289
290	default:
291		error = EINVAL;
292		break;
293	}
294
295	if (!error)
296		error = iicbus_stop(parent);
297
298	return (error);
299}
300
301static int
302iicsmb_sendb(device_t dev, u_char slave, char byte)
303{
304	device_t parent = device_get_parent(dev);
305	int error, sent;
306
307	error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT);
308
309	if (!error) {
310		error = iicbus_write(parent, &byte, 1, &sent, IICBUS_TIMEOUT);
311
312		iicbus_stop(parent);
313	}
314
315	return (error);
316}
317
318static int
319iicsmb_recvb(device_t dev, u_char slave, char *byte)
320{
321	device_t parent = device_get_parent(dev);
322	int error, read;
323
324	error = iicbus_start(parent, slave | LSB, 0);
325
326	if (!error) {
327		error = iicbus_read(parent, byte, 1, &read, IIC_LAST_READ, IICBUS_TIMEOUT);
328
329		iicbus_stop(parent);
330	}
331
332	return (error);
333}
334
335static int
336iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte)
337{
338	device_t parent = device_get_parent(dev);
339	int error, sent;
340
341	error = iicbus_start(parent, slave & ~LSB, 0);
342
343	if (!error) {
344		if (!(error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
345			error = iicbus_write(parent, &byte, 1, &sent, IICBUS_TIMEOUT);
346
347		iicbus_stop(parent);
348	}
349
350	return (error);
351}
352
353static int
354iicsmb_writew(device_t dev, u_char slave, char cmd, short word)
355{
356	device_t parent = device_get_parent(dev);
357	int error, sent;
358
359	char low = (char)(word & 0xff);
360	char high = (char)((word & 0xff00) >> 8);
361
362	error = iicbus_start(parent, slave & ~LSB, 0);
363
364	if (!error) {
365		if (!(error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
366		  if (!(error = iicbus_write(parent, &low, 1, &sent, IICBUS_TIMEOUT)))
367		    error = iicbus_write(parent, &high, 1, &sent, IICBUS_TIMEOUT);
368
369		iicbus_stop(parent);
370	}
371
372	return (error);
373}
374
375static int
376iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte)
377{
378	device_t parent = device_get_parent(dev);
379	int error, sent, read;
380
381	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
382		return (error);
383
384	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
385		goto error;
386
387	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
388		goto error;
389
390	if ((error = iicbus_read(parent, byte, 1, &read, IIC_LAST_READ, IICBUS_TIMEOUT)))
391		goto error;
392
393error:
394	iicbus_stop(parent);
395	return (error);
396}
397
398#define BUF2SHORT(low,high) \
399	((short)(((high) & 0xff) << 8) | (short)((low) & 0xff))
400
401static int
402iicsmb_readw(device_t dev, u_char slave, char cmd, short *word)
403{
404	device_t parent = device_get_parent(dev);
405	int error, sent, read;
406	char buf[2];
407
408	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
409		return (error);
410
411	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
412		goto error;
413
414	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
415		goto error;
416
417	if ((error = iicbus_read(parent, buf, 2, &read, IIC_LAST_READ, IICBUS_TIMEOUT)))
418		goto error;
419
420	/* first, receive low, then high byte */
421	*word = BUF2SHORT(buf[0], buf[1]);
422
423error:
424	iicbus_stop(parent);
425	return (error);
426}
427
428static int
429iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata)
430{
431	device_t parent = device_get_parent(dev);
432	int error, sent, read;
433	char buf[2];
434
435	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
436		return (error);
437
438	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
439		goto error;
440
441	/* first, send low, then high byte */
442	buf[0] = (char)(sdata & 0xff);
443	buf[1] = (char)((sdata & 0xff00) >> 8);
444
445	if ((error = iicbus_write(parent, buf, 2, &sent, IICBUS_TIMEOUT)))
446		goto error;
447
448	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
449		goto error;
450
451	if ((error = iicbus_read(parent, buf, 2, &read, IIC_LAST_READ, IICBUS_TIMEOUT)))
452		goto error;
453
454	/* first, receive low, then high byte */
455	*rdata = BUF2SHORT(buf[0], buf[1]);
456
457error:
458	iicbus_stop(parent);
459	return (error);
460}
461
462static int
463iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
464{
465	device_t parent = device_get_parent(dev);
466	int error, sent;
467
468	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
469		goto error;
470
471	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
472		goto error;
473
474	if ((error = iicbus_write(parent, buf, (int)count, &sent, IICBUS_TIMEOUT)))
475		goto error;
476
477	if ((error = iicbus_stop(parent)))
478		goto error;
479
480error:
481	return (error);
482}
483
484static int
485iicsmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf)
486{
487	device_t parent = device_get_parent(dev);
488	int error, sent, read;
489
490	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
491		return (error);
492
493	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
494		goto error;
495
496	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
497		goto error;
498
499	if ((error = iicbus_read(parent, buf, (int)*count, &read,
500						IIC_LAST_READ, IICBUS_TIMEOUT)))
501		goto error;
502	*count = read;
503
504error:
505	iicbus_stop(parent);
506	return (error);
507}
508
509DRIVER_MODULE(iicsmb, iicbus, iicsmb_driver, iicsmb_devclass, 0, 0);
510DRIVER_MODULE(smbus, iicsmb, smbus_driver, smbus_devclass, 0, 0);
511MODULE_DEPEND(iicsmb, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
512MODULE_DEPEND(iicsmb, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
513MODULE_VERSION(iicsmb, 1);
514