summaryrefslogtreecommitdiffstats
path: root/sys/dev/iicbus/iicsmb.c
blob: 27f1d2b055295881d121d5300dc184df09feefbe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
/*-
 * Copyright (c) 1998, 2001 Nicolas Souchu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * I2C to SMB bridge
 *
 * Example:
 *
 *     smb bttv
 *       \ /
 *      smbus
 *       /  \
 *    iicsmb bti2c
 *       |
 *     iicbus
 *     /  |  \
 *  iicbb pcf ...
 *    |
 *  lpbb
 */

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/systm.h>
#include <sys/uio.h>

#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>

#include <dev/smbus/smbconf.h>

#include "iicbus_if.h"
#include "smbus_if.h"

struct iicsmb_softc {

#define SMB_WAITING_ADDR	0x0
#define SMB_WAITING_LOW		0x1
#define SMB_WAITING_HIGH	0x2
#define SMB_DONE		0x3
	int state;

	u_char devaddr;			/* slave device address */

	char low;			/* low byte received first */
	char high;			/* high byte */

	struct mtx lock;
	device_t smbus;
};

static int iicsmb_probe(device_t);
static int iicsmb_attach(device_t);
static int iicsmb_detach(device_t);
static void iicsmb_identify(driver_t *driver, device_t parent);

static int iicsmb_intr(device_t dev, int event, char *buf);
static int iicsmb_callback(device_t dev, int index, void *data);
static int iicsmb_quick(device_t dev, u_char slave, int how);
static int iicsmb_sendb(device_t dev, u_char slave, char byte);
static int iicsmb_recvb(device_t dev, u_char slave, char *byte);
static int iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte);
static int iicsmb_writew(device_t dev, u_char slave, char cmd, short word);
static int iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte);
static int iicsmb_readw(device_t dev, u_char slave, char cmd, short *word);
static int iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata);
static int iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf);
static int iicsmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf);

static devclass_t iicsmb_devclass;

static device_method_t iicsmb_methods[] = {
	/* device interface */
	DEVMETHOD(device_identify,	iicsmb_identify),
	DEVMETHOD(device_probe,		iicsmb_probe),
	DEVMETHOD(device_attach,	iicsmb_attach),
	DEVMETHOD(device_detach,	iicsmb_detach),

	/* iicbus interface */
	DEVMETHOD(iicbus_intr,		iicsmb_intr),

	/* smbus interface */
	DEVMETHOD(smbus_callback,	iicsmb_callback),
	DEVMETHOD(smbus_quick,		iicsmb_quick),
	DEVMETHOD(smbus_sendb,		iicsmb_sendb),
	DEVMETHOD(smbus_recvb,		iicsmb_recvb),
	DEVMETHOD(smbus_writeb,		iicsmb_writeb),
	DEVMETHOD(smbus_writew,		iicsmb_writew),
	DEVMETHOD(smbus_readb,		iicsmb_readb),
	DEVMETHOD(smbus_readw,		iicsmb_readw),
	DEVMETHOD(smbus_pcall,		iicsmb_pcall),
	DEVMETHOD(smbus_bwrite,		iicsmb_bwrite),
	DEVMETHOD(smbus_bread,		iicsmb_bread),

	DEVMETHOD_END
};

static driver_t iicsmb_driver = {
	"iicsmb",
	iicsmb_methods,
	sizeof(struct iicsmb_softc),
};

#define IICBUS_TIMEOUT	100	/* us */

static void
iicsmb_identify(driver_t *driver, device_t parent)
{

	if (device_find_child(parent, "iicsmb", -1) == NULL)
		BUS_ADD_CHILD(parent, 0, "iicsmb", -1);
}

static int
iicsmb_probe(device_t dev)
{
	device_set_desc(dev, "SMBus over I2C bridge");
	return (BUS_PROBE_NOWILDCARD);
}

static int
iicsmb_attach(device_t dev)
{
	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);

	mtx_init(&sc->lock, "iicsmb", NULL, MTX_DEF);

	sc->smbus = device_add_child(dev, "smbus", -1);

	/* probe and attach the smbus */
	bus_generic_attach(dev);

	return (0);
}

static int
iicsmb_detach(device_t dev)
{
	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
	
	bus_generic_detach(dev);
	if (sc->smbus) {
		device_delete_child(dev, sc->smbus);
	}
	mtx_destroy(&sc->lock);

	return (0);
}

/*
 * iicsmb_intr()
 *
 * iicbus interrupt handler
 */
static int
iicsmb_intr(device_t dev, int event, char *buf)
{
	struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);

	mtx_lock(&sc->lock);
	switch (event) {
	case INTR_GENERAL:
	case INTR_START:
		sc->state = SMB_WAITING_ADDR;
		break;

	case INTR_STOP:
		/* call smbus intr handler */
		smbus_intr(sc->smbus, sc->devaddr,
				sc->low, sc->high, SMB_ENOERR);
		break;

	case INTR_RECEIVE:
		switch (sc->state) {
		case SMB_DONE:
			/* XXX too much data, discard */
			printf("%s: too much data from 0x%x\n", __func__,
				sc->devaddr & 0xff);
			goto end;

		case SMB_WAITING_ADDR:
			sc->devaddr = (u_char)*buf;
			sc->state = SMB_WAITING_LOW;
			break;

		case SMB_WAITING_LOW:
			sc->low = *buf;
			sc->state = SMB_WAITING_HIGH;
			break;

		case SMB_WAITING_HIGH:
			sc->high = *buf;
			sc->state = SMB_DONE;
			break;
		}
end:
		break;

	case INTR_TRANSMIT:
	case INTR_NOACK:
		break;

	case INTR_ERROR:
		switch (*buf) {
		case IIC_EBUSERR:
			smbus_intr(sc->smbus, sc->devaddr, 0, 0, SMB_EBUSERR);
			break;

		default:
			printf("%s unknown error 0x%x!\n", __func__,
								(int)*buf);
			break;
		}
		break;

	default:
		panic("%s: unknown event (%d)!", __func__, event);
	}
	mtx_unlock(&sc->lock);

	return (0);
}

static int
iicsmb_callback(device_t dev, int index, void *data)
{
	device_t parent = device_get_parent(dev);
	int error = 0;
	int how;

	switch (index) {
	case SMB_REQUEST_BUS:
		/* request underlying iicbus */
		how = *(int *)data;
		error = iicbus_request_bus(parent, dev, how);
		break;

	case SMB_RELEASE_BUS:
		/* release underlying iicbus */
		error = iicbus_release_bus(parent, dev);
		break;

	default:
		error = EINVAL;
	}

	return (error);
}

static int
iicsmb_quick(device_t dev, u_char slave, int how)
{
	device_t parent = device_get_parent(dev);
	int error;

	switch (how) {
	case SMB_QWRITE:
		error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT);
		break;

	case SMB_QREAD:
		error = iicbus_start(parent, slave | LSB, IICBUS_TIMEOUT);
		break;

	default:
		error = EINVAL;
		break;
	}

	if (!error)
		error = iicbus_stop(parent);
		
	return (error);
}

static int
iicsmb_sendb(device_t dev, u_char slave, char byte)
{
	device_t parent = device_get_parent(dev);
	int error, sent;

	error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT);

	if (!error) {
		error = iicbus_write(parent, &byte, 1, &sent, IICBUS_TIMEOUT);

		iicbus_stop(parent);
	}

	return (error);
}

static int
iicsmb_recvb(device_t dev, u_char slave, char *byte)
{
	device_t parent = device_get_parent(dev);
	int error, read;

	error = iicbus_start(parent, slave | LSB, 0);

	if (!error) {
		error = iicbus_read(parent, byte, 1, &read, IIC_LAST_READ, IICBUS_TIMEOUT);

		iicbus_stop(parent);
	}

	return (error);
}

static int
iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte)
{
	device_t parent = device_get_parent(dev);
	int error, sent;

	error = iicbus_start(parent, slave & ~LSB, 0);

	if (!error) {
		if (!(error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
			error = iicbus_write(parent, &byte, 1, &sent, IICBUS_TIMEOUT);

		iicbus_stop(parent);
	}

	return (error);
}

static int
iicsmb_writew(device_t dev, u_char slave, char cmd, short word)
{
	device_t parent = device_get_parent(dev);
	int error, sent;

	char low = (char)(word & 0xff);
	char high = (char)((word & 0xff00) >> 8);

	error = iicbus_start(parent, slave & ~LSB, 0);

	if (!error) {
		if (!(error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
		  if (!(error = iicbus_write(parent, &low, 1, &sent, IICBUS_TIMEOUT)))
		    error = iicbus_write(parent, &high, 1, &sent, IICBUS_TIMEOUT);

		iicbus_stop(parent);
	}

	return (error);
}

static int
iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte)
{
	device_t parent = device_get_parent(dev);
	int error, sent, read;

	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
		return (error);

	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_read(parent, byte, 1, &read, IIC_LAST_READ, IICBUS_TIMEOUT)))
		goto error;

error:
	iicbus_stop(parent);
	return (error);
}

#define BUF2SHORT(low,high) \
	((short)(((high) & 0xff) << 8) | (short)((low) & 0xff))

static int
iicsmb_readw(device_t dev, u_char slave, char cmd, short *word)
{
	device_t parent = device_get_parent(dev);
	int error, sent, read;
	char buf[2];

	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
		return (error);

	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_read(parent, buf, 2, &read, IIC_LAST_READ, IICBUS_TIMEOUT)))
		goto error;

	/* first, receive low, then high byte */
	*word = BUF2SHORT(buf[0], buf[1]);

error:
	iicbus_stop(parent);
	return (error);
}

static int
iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata)
{
	device_t parent = device_get_parent(dev);
	int error, sent, read;
	char buf[2];

	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
		return (error);

	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
		goto error;

	/* first, send low, then high byte */
	buf[0] = (char)(sdata & 0xff);
	buf[1] = (char)((sdata & 0xff00) >> 8);

	if ((error = iicbus_write(parent, buf, 2, &sent, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_read(parent, buf, 2, &read, IIC_LAST_READ, IICBUS_TIMEOUT)))
		goto error;

	/* first, receive low, then high byte */
	*rdata = BUF2SHORT(buf[0], buf[1]);

error:
	iicbus_stop(parent);
	return (error);
}

static int
iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
{
	device_t parent = device_get_parent(dev);
	int error, sent;

	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_write(parent, buf, (int)count, &sent, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_stop(parent)))
		goto error;

error:
	return (error);
}

static int
iicsmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf)
{
	device_t parent = device_get_parent(dev);
	int error, sent, read;

	if ((error = iicbus_start(parent, slave & ~LSB, IICBUS_TIMEOUT)))
		return (error);

	if ((error = iicbus_write(parent, &cmd, 1, &sent, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_repeated_start(parent, slave | LSB, IICBUS_TIMEOUT)))
		goto error;

	if ((error = iicbus_read(parent, buf, (int)*count, &read,
						IIC_LAST_READ, IICBUS_TIMEOUT)))
		goto error;
	*count = read;

error:
	iicbus_stop(parent);
	return (error);
}

DRIVER_MODULE(iicsmb, iicbus, iicsmb_driver, iicsmb_devclass, 0, 0);
DRIVER_MODULE(smbus, iicsmb, smbus_driver, smbus_devclass, 0, 0);
MODULE_DEPEND(iicsmb, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
MODULE_DEPEND(iicsmb, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
MODULE_VERSION(iicsmb, 1);
OpenPOWER on IntegriCloud