iicsmb.c revision 50477 
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: head/sys/dev/iicbus/iicsmb.c 50477 1999-08-28 01:08:13Z peter $
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/conf.h>
54#include <sys/buf.h>
55#include <sys/uio.h>
56#include <sys/malloc.h>
57
58#include <machine/clock.h>
59
60#include <dev/iicbus/iiconf.h>
61#include <dev/iicbus/iicbus.h>
62
63#include <dev/smbus/smbconf.h>
64
65#include "iicbus_if.h"
66#include "smbus_if.h"
67
68struct iicsmb_softc {
69
70#define SMB_WAITING_ADDR	0x0
71#define SMB_WAITING_LOW		0x1
72#define SMB_WAITING_HIGH	0x2
73#define SMB_DONE		0x3
74	int state;
75
76	u_char devaddr;			/* slave device address */
77
78	char low;			/* low byte received first */
79	char high;			/* high byte */
80
81	device_t smbus;
82};
83
84static int iicsmb_probe(device_t);
85static int iicsmb_attach(device_t);
86
87static void iicsmb_intr(device_t dev, int event, char *buf);
88static int iicsmb_callback(device_t dev, int index, caddr_t data);
89static int iicsmb_quick(device_t dev, u_char slave, int how);
90static int iicsmb_sendb(device_t dev, u_char slave, char byte);
91static int iicsmb_recvb(device_t dev, u_char slave, char *byte);
92static int iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte);
93static int iicsmb_writew(device_t dev, u_char slave, char cmd, short word);
94static int iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte);
95static int iicsmb_readw(device_t dev, u_char slave, char cmd, short *word);
96static int iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata);
97static int iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf);
98static int iicsmb_bread(device_t dev, u_char slave, char cmd, u_char count, char *buf);
99
100static devclass_t iicsmb_devclass;
101
102static device_method_t iicsmb_methods[] = {
103	/* device interface */
104	DEVMETHOD(device_probe,		iicsmb_probe),
105	DEVMETHOD(device_attach,	iicsmb_attach),
106
107	/* bus interface */
108	DEVMETHOD(bus_print_child,	bus_generic_print_child),
109
110	/* iicbus interface */
111	DEVMETHOD(iicbus_intr,		iicsmb_intr),
112
113	/* smbus interface */
114	DEVMETHOD(smbus_callback,	iicsmb_callback),
115	DEVMETHOD(smbus_quick,		iicsmb_quick),
116	DEVMETHOD(smbus_sendb,		iicsmb_sendb),
117	DEVMETHOD(smbus_recvb,		iicsmb_recvb),
118	DEVMETHOD(smbus_writeb,		iicsmb_writeb),
119	DEVMETHOD(smbus_writew,		iicsmb_writew),
120	DEVMETHOD(smbus_readb,		iicsmb_readb),
121	DEVMETHOD(smbus_readw,		iicsmb_readw),
122	DEVMETHOD(smbus_pcall,		iicsmb_pcall),
123	DEVMETHOD(smbus_bwrite,		iicsmb_bwrite),
124	DEVMETHOD(smbus_bread,		iicsmb_bread),
125
126	{ 0, 0 }
127};
128
129static driver_t iicsmb_driver = {
130	"iicsmb",
131	iicsmb_methods,
132	sizeof(struct iicsmb_softc),
133};
134
135static int
136iicsmb_probe(device_t dev)
137{
138	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
139
140	sc->smbus = smbus_alloc_bus(dev);
141
142	if (!sc->smbus)
143		return (EINVAL);	/* XXX don't know what to return else */
144
145	return (0);
146}
147
148static int
149iicsmb_attach(device_t dev)
150{
151	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
152
153	/* probe and attach the smbus */
154	device_probe_and_attach(sc->smbus);
155
156	return (0);
157}
158
159/*
160 * iicsmb_intr()
161 *
162 * iicbus interrupt handler
163 */
164static void
165iicsmb_intr(device_t dev, int event, char *buf)
166{
167	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
168
169	switch (event) {
170	case INTR_GENERAL:
171	case INTR_START:
172		sc->state = SMB_WAITING_ADDR;
173		break;
174
175	case INTR_STOP:
176		/* call smbus intr handler */
177		smbus_intr(sc->smbus, sc->devaddr,
178				sc->low, sc->high, SMB_ENOERR);
179		break;
180
181	case INTR_RECEIVE:
182		switch (sc->state) {
183		case SMB_DONE:
184			/* XXX too much data, discard */
185			printf("%s: too much data from 0x%x\n", __FUNCTION__,
186				sc->devaddr & 0xff);
187			goto end;
188
189		case SMB_WAITING_ADDR:
190			sc->devaddr = (u_char)*buf;
191			sc->state = SMB_WAITING_LOW;
192			break;
193
194		case SMB_WAITING_LOW:
195			sc->low = *buf;
196			sc->state = SMB_WAITING_HIGH;
197			break;
198
199		case SMB_WAITING_HIGH:
200			sc->high = *buf;
201			sc->state = SMB_DONE;
202			break;
203		}
204end:
205		break;
206
207	case INTR_TRANSMIT:
208	case INTR_NOACK:
209		break;
210
211	case INTR_ERROR:
212		switch (*buf) {
213		case IIC_EBUSERR:
214			smbus_intr(sc->smbus, sc->devaddr, 0, 0, SMB_EBUSERR);
215			break;
216
217		default:
218			printf("%s unknown error 0x%x!\n", __FUNCTION__,
219								(int)*buf);
220			break;
221		}
222		break;
223
224	default:
225		panic("%s: unknown event (%d)!", __FUNCTION__, event);
226	}
227
228	return;
229}
230
231static int
232iicsmb_callback(device_t dev, int index, caddr_t data)
233{
234	device_t parent = device_get_parent(dev);
235	int error = 0;
236	int how;
237
238	switch (index) {
239	case SMB_REQUEST_BUS:
240		/* request underlying iicbus */
241		how = *(int *)data;
242		error = iicbus_request_bus(parent, dev, how);
243		break;
244
245	case SMB_RELEASE_BUS:
246		/* release underlying iicbus */
247		error = iicbus_release_bus(parent, dev);
248		break;
249
250	default:
251		error = EINVAL;
252	}
253
254	return (error);
255}
256
257static int
258iicsmb_quick(device_t dev, u_char slave, int how)
259{
260	device_t parent = device_get_parent(dev);
261	int error;
262
263	switch (how) {
264	case SMB_QWRITE:
265		error = iicbus_start(parent, slave & ~LSB, 0);
266		break;
267
268	case SMB_QREAD:
269		error = iicbus_start(parent, slave | LSB, 0);
270		break;
271
272	default:
273		error = EINVAL;
274		break;
275	}
276
277	if (!error)
278		error = iicbus_stop(parent);
279
280	return (error);
281}
282
283static int
284iicsmb_sendb(device_t dev, u_char slave, char byte)
285{
286	device_t parent = device_get_parent(dev);
287	int error, sent;
288
289	error = iicbus_start(parent, slave & ~LSB, 0);
290
291	if (!error) {
292		error = iicbus_write(parent, &byte, 1, &sent, 0);
293
294		iicbus_stop(parent);
295	}
296
297	return (error);
298}
299
300static int
301iicsmb_recvb(device_t dev, u_char slave, char *byte)
302{
303	device_t parent = device_get_parent(dev);
304	int error, read;
305
306	error = iicbus_start(parent, slave | LSB, 0);
307
308	if (!error) {
309		error = iicbus_read(parent, byte, 1, &read, IIC_LAST_READ, 0);
310
311		iicbus_stop(parent);
312	}
313
314	return (error);
315}
316
317static int
318iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte)
319{
320	device_t parent = device_get_parent(dev);
321	int error, sent;
322
323	error = iicbus_start(parent, slave & ~LSB, 0);
324
325	if (!error) {
326		if (!(error = iicbus_write(parent, &cmd, 1, &sent, 0)))
327			error = iicbus_write(parent, &byte, 1, &sent, 0);
328
329		iicbus_stop(parent);
330	}
331
332	return (error);
333}
334
335static int
336iicsmb_writew(device_t dev, u_char slave, char cmd, short word)
337{
338	device_t parent = device_get_parent(dev);
339	int error, sent;
340
341	char low = (char)(word & 0xff);
342	char high = (char)((word & 0xff00) >> 8);
343
344	error = iicbus_start(parent, slave & ~LSB, 0);
345
346	if (!error) {
347		if (!(error = iicbus_write(parent, &cmd, 1, &sent, 0)))
348		  if (!(error = iicbus_write(parent, &low, 1, &sent, 0)))
349		    error = iicbus_write(parent, &high, 1, &sent, 0);
350
351		iicbus_stop(parent);
352	}
353
354	return (error);
355}
356
357static int
358iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte)
359{
360	device_t parent = device_get_parent(dev);
361	int error, sent, read;
362
363	if ((error = iicbus_start(parent, slave & ~LSB, 0)))
364		return (error);
365
366	if ((error = iicbus_write(parent, &cmd, 1, &sent, 0)))
367		goto error;
368
369	if ((error = iicbus_repeated_start(parent, slave | LSB, 0)))
370		goto error;
371
372	if ((error = iicbus_read(parent, byte, 1, &read, IIC_LAST_READ, 0)))
373		goto error;
374
375error:
376	iicbus_stop(parent);
377	return (error);
378}
379
380#define BUF2SHORT(low,high) \
381	((short)(((high) & 0xff) << 8) | (short)((low) & 0xff))
382
383static int
384iicsmb_readw(device_t dev, u_char slave, char cmd, short *word)
385{
386	device_t parent = device_get_parent(dev);
387	int error, sent, read;
388	char buf[2];
389
390	if ((error = iicbus_start(parent, slave & ~LSB, 0)))
391		return (error);
392
393	if ((error = iicbus_write(parent, &cmd, 1, &sent, 0)))
394		goto error;
395
396	if ((error = iicbus_repeated_start(parent, slave | LSB, 0)))
397		goto error;
398
399	if ((error = iicbus_read(parent, buf, 2, &read, IIC_LAST_READ, 0)))
400		goto error;
401
402	/* first, receive low, then high byte */
403	*word = BUF2SHORT(buf[0], buf[1]);
404
405error:
406	iicbus_stop(parent);
407	return (error);
408}
409
410static int
411iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata)
412{
413	device_t parent = device_get_parent(dev);
414	int error, sent, read;
415	char buf[2];
416
417	if ((error = iicbus_start(parent, slave & ~LSB, 0)))
418		return (error);
419
420	if ((error = iicbus_write(parent, &cmd, 1, &sent, 0)))
421		goto error;
422
423	/* first, send low, then high byte */
424	buf[0] = (char)(sdata & 0xff);
425	buf[1] = (char)((sdata & 0xff00) >> 8);
426
427	if ((error = iicbus_write(parent, buf, 2, &sent, 0)))
428		goto error;
429
430	if ((error = iicbus_repeated_start(parent, slave | LSB, 0)))
431		goto error;
432
433	if ((error = iicbus_read(parent, buf, 2, &read, IIC_LAST_READ, 0)))
434		goto error;
435
436	/* first, receive low, then high byte */
437	*rdata = BUF2SHORT(buf[0], buf[1]);
438
439error:
440	iicbus_stop(parent);
441	return (error);
442}
443
444static int
445iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
446{
447	device_t parent = device_get_parent(dev);
448	int error, sent;
449
450	if ((error = iicbus_start(parent, slave & ~LSB, 0)))
451		goto error;
452
453	if ((error = iicbus_write(parent, &cmd, 1, &sent, 0)))
454		goto error;
455
456	if ((error = iicbus_write(parent, buf, (int)count, &sent, 0)))
457		goto error;
458
459	if ((error = iicbus_stop(parent)))
460		goto error;
461
462error:
463	return (error);
464}
465
466static int
467iicsmb_bread(device_t dev, u_char slave, char cmd, u_char count, char *buf)
468{
469	device_t parent = device_get_parent(dev);
470	int error, sent, read;
471
472	if ((error = iicbus_start(parent, slave & ~LSB, 0)))
473		return (error);
474
475	if ((error = iicbus_write(parent, &cmd, 1, &sent, 0)))
476		goto error;
477
478	if ((error = iicbus_repeated_start(parent, slave | LSB, 0)))
479		goto error;
480
481	if ((error = iicbus_read(parent, buf, (int)count, &read,
482							IIC_LAST_READ, 0)))
483		goto error;
484
485error:
486	iicbus_stop(parent);
487	return (error);
488}
489
490DRIVER_MODULE(iicsmb, iicbus, iicsmb_driver, iicsmb_devclass, 0, 0);
491