1/*-
2 * Copyright (c) 1998 Nicolas Souchu, Marc Bouget
3 * Copyright (c) 2004 Joerg Wunsch
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD$");
30
31#include <sys/param.h>
32#include <sys/bus.h>
33#include <sys/lock.h>
34#include <sys/kernel.h>
35#include <sys/module.h>
36#include <sys/mutex.h>
37#include <sys/systm.h>
38
39#include <machine/bus.h>
40#include <machine/resource.h>
41
42#include <sys/rman.h>
43
44#include <dev/iicbus/iicbus.h>
45#include <dev/iicbus/iiconf.h>
46#include <dev/pcf/pcfvar.h>
47#include "iicbus_if.h"
48
49/* Not so official debugging option. */
50/* #define PCFDEBUG */
51
52static int pcf_wait_byte(struct pcf_softc *pcf);
53static int pcf_noack(struct pcf_softc *pcf, int timeout);
54static void pcf_stop_locked(struct pcf_softc *pcf);
55
56/*
57 * Polling mode for master operations wait for a new
58 * byte incoming or outgoing
59 */
60static int
61pcf_wait_byte(struct pcf_softc *sc)
62{
63	int counter = TIMEOUT;
64
65	PCF_ASSERT_LOCKED(sc);
66	while (counter--) {
67
68		if ((pcf_get_S1(sc) & PIN) == 0)
69			return (0);
70	}
71
72#ifdef PCFDEBUG
73	printf("pcf: timeout!\n");
74#endif
75
76	return (IIC_ETIMEOUT);
77}
78
79static void
80pcf_stop_locked(struct pcf_softc *sc)
81{
82
83	PCF_ASSERT_LOCKED(sc);
84#ifdef PCFDEBUG
85	device_printf(dev, " >> stop\n");
86#endif
87	/*
88	 * Send STOP condition iff the START condition was previously sent.
89	 * STOP is sent only once even if an iicbus_stop() is called after
90	 * an iicbus_read()... see pcf_read(): the PCF needs to send the stop
91	 * before the last char is read.
92	 */
93	if (sc->pcf_started) {
94		/* set stop condition and enable IT */
95		pcf_set_S1(sc, PIN|ESO|ENI|STO|ACK);
96
97		sc->pcf_started = 0;
98	}
99}
100
101static int
102pcf_noack(struct pcf_softc *sc, int timeout)
103{
104	int noack;
105	int k = timeout/10;
106
107	PCF_ASSERT_LOCKED(sc);
108	do {
109		noack = pcf_get_S1(sc) & LRB;
110		if (!noack)
111			break;
112		DELAY(10);				/* XXX wait 10 us */
113	} while (k--);
114
115	return (noack);
116}
117
118int
119pcf_repeated_start(device_t dev, u_char slave, int timeout)
120{
121	struct pcf_softc *sc = DEVTOSOFTC(dev);
122	int error = 0;
123
124	PCF_LOCK(sc);
125#ifdef PCFDEBUG
126	device_printf(dev, " >> repeated start for slave %#x\n",
127		      (unsigned)slave);
128#endif
129	/* repeated start */
130	pcf_set_S1(sc, ESO|STA|STO|ACK);
131
132	/* set slave address to PCF. Last bit (LSB) must be set correctly
133	 * according to transfer direction */
134	pcf_set_S0(sc, slave);
135
136	/* wait for address sent, polling */
137	if ((error = pcf_wait_byte(sc)))
138		goto error;
139
140	/* check for ack */
141	if (pcf_noack(sc, timeout)) {
142		error = IIC_ENOACK;
143#ifdef PCFDEBUG
144		printf("pcf: no ack on repeated_start!\n");
145#endif
146		goto error;
147	}
148
149	PCF_UNLOCK(sc);
150	return (0);
151
152error:
153	pcf_stop_locked(sc);
154	PCF_UNLOCK(sc);
155	return (error);
156}
157
158int
159pcf_start(device_t dev, u_char slave, int timeout)
160{
161	struct pcf_softc *sc = DEVTOSOFTC(dev);
162	int error = 0;
163
164	PCF_LOCK(sc);
165#ifdef PCFDEBUG
166	device_printf(dev, " >> start for slave %#x\n", (unsigned)slave);
167#endif
168	if ((pcf_get_S1(sc) & nBB) == 0) {
169#ifdef PCFDEBUG
170		printf("pcf: busy!\n");
171#endif
172		PCF_UNLOCK(sc);
173		return (IIC_EBUSBSY);
174	}
175
176	/* set slave address to PCF. Last bit (LSB) must be set correctly
177	 * according to transfer direction */
178	pcf_set_S0(sc, slave);
179
180	/* START only */
181	pcf_set_S1(sc, PIN|ESO|STA|ACK);
182
183	sc->pcf_started = 1;
184
185	/* wait for address sent, polling */
186	if ((error = pcf_wait_byte(sc)))
187		goto error;
188
189	/* check for ACK */
190	if (pcf_noack(sc, timeout)) {
191		error = IIC_ENOACK;
192#ifdef PCFDEBUG
193		printf("pcf: no ack on start!\n");
194#endif
195		goto error;
196	}
197
198	PCF_UNLOCK(sc);
199	return (0);
200
201error:
202	pcf_stop_locked(sc);
203	PCF_UNLOCK(sc);
204	return (error);
205}
206
207int
208pcf_stop(device_t dev)
209{
210	struct pcf_softc *sc = DEVTOSOFTC(dev);
211
212#ifdef PCFDEBUG
213	device_printf(dev, " >> stop\n");
214#endif
215	PCF_LOCK(sc);
216	pcf_stop_locked(sc);
217	PCF_UNLOCK(sc);
218
219	return (0);
220}
221
222void
223pcf_intr(void *arg)
224{
225	struct pcf_softc *sc = arg;
226	char data, status, addr;
227	char error = 0;
228
229	PCF_LOCK(sc);
230	status = pcf_get_S1(sc);
231
232	if (status & PIN) {
233		printf("pcf: spurious interrupt, status=0x%x\n",
234		       status & 0xff);
235
236		goto error;
237	}
238
239	if (status & LAB)
240		printf("pcf: bus arbitration lost!\n");
241
242	if (status & BER) {
243		error = IIC_EBUSERR;
244		iicbus_intr(sc->iicbus, INTR_ERROR, &error);
245
246		goto error;
247	}
248
249	do {
250		status = pcf_get_S1(sc);
251
252		switch(sc->pcf_slave_mode) {
253
254		case SLAVE_TRANSMITTER:
255			if (status & LRB) {
256				/* ack interrupt line */
257				dummy_write(sc);
258
259				/* no ack, don't send anymore */
260				sc->pcf_slave_mode = SLAVE_RECEIVER;
261
262				iicbus_intr(sc->iicbus, INTR_NOACK, NULL);
263				break;
264			}
265
266			/* get data from upper code */
267			iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
268
269			pcf_set_S0(sc, data);
270			break;
271
272		case SLAVE_RECEIVER:
273			if (status & AAS) {
274				addr = pcf_get_S0(sc);
275
276				if (status & AD0)
277					iicbus_intr(sc->iicbus, INTR_GENERAL, &addr);
278				else
279					iicbus_intr(sc->iicbus, INTR_START, &addr);
280
281				if (addr & LSB) {
282					sc->pcf_slave_mode = SLAVE_TRANSMITTER;
283
284					/* get the first char from upper code */
285					iicbus_intr(sc->iicbus, INTR_TRANSMIT, &data);
286
287					/* send first data byte */
288					pcf_set_S0(sc, data);
289				}
290
291				break;
292			}
293
294			/* stop condition received? */
295			if (status & STS) {
296				/* ack interrupt line */
297				dummy_read(sc);
298
299				/* emulate intr stop condition */
300				iicbus_intr(sc->iicbus, INTR_STOP, NULL);
301
302			} else {
303				/* get data, ack interrupt line */
304				data = pcf_get_S0(sc);
305
306				/* deliver the character */
307				iicbus_intr(sc->iicbus, INTR_RECEIVE, &data);
308			}
309			break;
310
311		    default:
312			panic("%s: unknown slave mode (%d)!", __func__,
313				sc->pcf_slave_mode);
314		    }
315
316	} while ((pcf_get_S1(sc) & PIN) == 0);
317	PCF_UNLOCK(sc);
318
319	return;
320
321error:
322	/* unknown event on bus...reset PCF */
323	pcf_set_S1(sc, PIN|ESO|ENI|ACK);
324
325	sc->pcf_slave_mode = SLAVE_RECEIVER;
326	PCF_UNLOCK(sc);
327
328	return;
329}
330
331int
332pcf_rst_card(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
333{
334	struct pcf_softc *sc = DEVTOSOFTC(dev);
335
336	PCF_LOCK(sc);
337	if (oldaddr)
338		*oldaddr = sc->pcf_addr;
339
340	/* retrieve own address from bus level */
341	if (!addr)
342		sc->pcf_addr = PCF_DEFAULT_ADDR;
343	else
344		sc->pcf_addr = addr;
345
346	pcf_set_S1(sc, PIN);				/* initialize S1 */
347
348	/* own address S'O<>0 */
349	pcf_set_S0(sc, sc->pcf_addr >> 1);
350
351	/* select clock register */
352	pcf_set_S1(sc, PIN|ES1);
353
354	/* select bus speed : 18=90kb, 19=45kb, 1A=11kb, 1B=1.5kb */
355	switch (speed) {
356	case IIC_SLOW:
357		pcf_set_S0(sc,  0x1b); /* XXX Sun uses 0x1f */
358		break;
359
360	case IIC_FAST:
361		pcf_set_S0(sc,  0x19); /* XXX Sun: 0x1d */
362		break;
363
364	case IIC_UNKNOWN:
365	case IIC_FASTEST:
366	default:
367		pcf_set_S0(sc,  0x18); /* XXX Sun: 0x1c */
368		break;
369	}
370
371	/* set bus on, ack=yes, INT=yes */
372	pcf_set_S1(sc, PIN|ESO|ENI|ACK);
373
374	sc->pcf_slave_mode = SLAVE_RECEIVER;
375	PCF_UNLOCK(sc);
376
377	return (0);
378}
379
380int
381pcf_write(device_t dev, const char *buf, int len, int *sent, int timeout /* us */)
382{
383	struct pcf_softc *sc = DEVTOSOFTC(dev);
384	int bytes, error = 0;
385
386#ifdef PCFDEBUG
387	device_printf(dev, " >> writing %d bytes: %#x%s\n", len,
388		      (unsigned)buf[0], len > 1? "...": "");
389#endif
390
391	bytes = 0;
392	PCF_LOCK(sc);
393	while (len) {
394
395		pcf_set_S0(sc, *buf++);
396
397		/* wait for the byte to be send */
398		if ((error = pcf_wait_byte(sc)))
399			goto error;
400
401		/* check if ack received */
402		if (pcf_noack(sc, timeout)) {
403			error = IIC_ENOACK;
404			goto error;
405		}
406
407		len --;
408		bytes ++;
409	}
410
411error:
412	*sent = bytes;
413	PCF_UNLOCK(sc);
414
415#ifdef PCFDEBUG
416	device_printf(dev, " >> %d bytes written (%d)\n", bytes, error);
417#endif
418
419	return (error);
420}
421
422int
423pcf_read(device_t dev, char *buf, int len, int *read, int last,
424	 int delay /* us */)
425{
426	struct pcf_softc *sc = DEVTOSOFTC(dev);
427	int bytes, error = 0;
428#ifdef PCFDEBUG
429	char *obuf = buf;
430
431	device_printf(dev, " << reading %d bytes\n", len);
432#endif
433
434	PCF_LOCK(sc);
435	/* trig the bus to get the first data byte in S0 */
436	if (len) {
437		if (len == 1 && last)
438			/* just one byte to read */
439			pcf_set_S1(sc, ESO);		/* no ack */
440
441		dummy_read(sc);
442	}
443
444	bytes = 0;
445	while (len) {
446
447		/* XXX delay needed here */
448
449		/* wait for trigged byte */
450		if ((error = pcf_wait_byte(sc))) {
451			pcf_stop_locked(sc);
452			goto error;
453		}
454
455		if (len == 1 && last)
456			/* ok, last data byte already in S0, no I2C activity
457			 * on next pcf_get_S0() */
458			pcf_stop_locked(sc);
459
460		else if (len == 2 && last)
461			/* next trigged byte with no ack */
462			pcf_set_S1(sc, ESO);
463
464		/* receive byte, trig next byte */
465		*buf++ = pcf_get_S0(sc);
466
467		len --;
468		bytes ++;
469	};
470
471error:
472	*read = bytes;
473	PCF_UNLOCK(sc);
474
475#ifdef PCFDEBUG
476	device_printf(dev, " << %d bytes read (%d): %#x%s\n", bytes, error,
477		      (unsigned)obuf[0], bytes > 1? "...": "");
478#endif
479
480	return (error);
481}
482
483DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0);
484MODULE_DEPEND(pcf, iicbus, PCF_MINVER, PCF_PREFVER, PCF_MAXVER);
485MODULE_VERSION(pcf, PCF_MODVER);
486