iiconf.c revision 289666 
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: stable/10/sys/dev/iicbus/iiconf.c 289666 2015-10-20 21:20:34Z ian $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/lock.h>
33#include <sys/malloc.h>
34#include <sys/module.h>
35#include <sys/mutex.h>
36#include <sys/bus.h>
37
38#include <dev/iicbus/iiconf.h>
39#include <dev/iicbus/iicbus.h>
40#include "iicbus_if.h"
41
42/*
43 * Translate IIC_Exxxxx status values to vaguely-equivelent errno values.
44 */
45int
46iic2errno(int iic_status)
47{
48	switch (iic_status) {
49	case IIC_NOERR:         return (0);
50	case IIC_EBUSERR:       return (EALREADY);
51	case IIC_ENOACK:        return (EIO);
52	case IIC_ETIMEOUT:      return (ETIMEDOUT);
53	case IIC_EBUSBSY:       return (EWOULDBLOCK);
54	case IIC_ESTATUS:       return (EPROTO);
55	case IIC_EUNDERFLOW:    return (EIO);
56	case IIC_EOVERFLOW:     return (EOVERFLOW);
57	case IIC_ENOTSUPP:      return (EOPNOTSUPP);
58	case IIC_ENOADDR:       return (EADDRNOTAVAIL);
59	case IIC_ERESOURCE:     return (ENOMEM);
60	default:                return (EIO);
61	}
62}
63
64/*
65 * iicbus_intr()
66 */
67void
68iicbus_intr(device_t bus, int event, char *buf)
69{
70	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
71
72	/* call owner's intr routine */
73	if (sc->owner)
74		IICBUS_INTR(sc->owner, event, buf);
75
76	return;
77}
78
79static int
80iicbus_poll(struct iicbus_softc *sc, int how)
81{
82	int error;
83
84	IICBUS_ASSERT_LOCKED(sc);
85	switch (how) {
86	case IIC_WAIT | IIC_INTR:
87		error = mtx_sleep(sc, &sc->lock, IICPRI|PCATCH, "iicreq", 0);
88		break;
89
90	case IIC_WAIT | IIC_NOINTR:
91		error = mtx_sleep(sc, &sc->lock, IICPRI, "iicreq", 0);
92		break;
93
94	default:
95		return (IIC_EBUSBSY);
96	}
97
98	return (error);
99}
100
101/*
102 * iicbus_request_bus()
103 *
104 * Allocate the device to perform transfers.
105 *
106 * how	: IIC_WAIT or IIC_DONTWAIT
107 */
108int
109iicbus_request_bus(device_t bus, device_t dev, int how)
110{
111	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
112	int error = 0;
113
114	IICBUS_LOCK(sc);
115
116	while ((error == 0) && (sc->owner != NULL))
117		error = iicbus_poll(sc, how);
118
119	if (error == 0) {
120		sc->owner = dev;
121		/*
122		 * Drop the lock around the call to the bus driver.
123		 * This call should be allowed to sleep in the IIC_WAIT case.
124		 * Drivers might also need to grab locks that would cause LOR
125		 * if our lock is held.
126		 */
127		IICBUS_UNLOCK(sc);
128		/* Ask the underlying layers if the request is ok */
129		error = IICBUS_CALLBACK(device_get_parent(bus),
130		    IIC_REQUEST_BUS, (caddr_t)&how);
131		IICBUS_LOCK(sc);
132
133		if (error != 0) {
134			sc->owner = NULL;
135			wakeup_one(sc);
136		}
137	}
138
139
140	IICBUS_UNLOCK(sc);
141
142	return (error);
143}
144
145/*
146 * iicbus_release_bus()
147 *
148 * Release the device allocated with iicbus_request_dev()
149 */
150int
151iicbus_release_bus(device_t bus, device_t dev)
152{
153	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
154	int error;
155
156	IICBUS_LOCK(sc);
157
158	if (sc->owner != dev) {
159		IICBUS_UNLOCK(sc);
160		return (IIC_EBUSBSY);
161	}
162
163	/*
164	 * Drop the lock around the call to the bus driver.
165	 * This call should be allowed to sleep in the IIC_WAIT case.
166	 * Drivers might also need to grab locks that would cause LOR
167	 * if our lock is held.
168	 */
169	IICBUS_UNLOCK(sc);
170	/* Ask the underlying layers if the release is ok */
171	error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
172
173	if (error == 0) {
174		IICBUS_LOCK(sc);
175		sc->owner = NULL;
176
177		/* wakeup a waiting thread */
178		wakeup_one(sc);
179		IICBUS_UNLOCK(sc);
180	}
181
182	return (error);
183}
184
185/*
186 * iicbus_started()
187 *
188 * Test if the iicbus is started by the controller
189 */
190int
191iicbus_started(device_t bus)
192{
193	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
194
195	return (sc->started);
196}
197
198/*
199 * iicbus_start()
200 *
201 * Send start condition to the slave addressed by 'slave'
202 */
203int
204iicbus_start(device_t bus, u_char slave, int timeout)
205{
206	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
207	int error = 0;
208
209	if (sc->started)
210		return (IIC_ESTATUS); /* protocol error, bus already started */
211
212	if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
213		sc->started = slave;
214	else
215		sc->started = 0;
216
217	return (error);
218}
219
220/*
221 * iicbus_repeated_start()
222 *
223 * Send start condition to the slave addressed by 'slave'
224 */
225int
226iicbus_repeated_start(device_t bus, u_char slave, int timeout)
227{
228	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
229	int error = 0;
230
231	if (!sc->started)
232		return (IIC_ESTATUS); /* protocol error, bus not started */
233
234	if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
235		sc->started = slave;
236	else
237		sc->started = 0;
238
239	return (error);
240}
241
242/*
243 * iicbus_stop()
244 *
245 * Send stop condition to the bus
246 */
247int
248iicbus_stop(device_t bus)
249{
250	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
251	int error = 0;
252
253	if (!sc->started)
254		return (IIC_ESTATUS); /* protocol error, bus not started */
255
256	error = IICBUS_STOP(device_get_parent(bus));
257
258	/* refuse any further access */
259	sc->started = 0;
260
261	return (error);
262}
263
264/*
265 * iicbus_write()
266 *
267 * Write a block of data to the slave previously started by
268 * iicbus_start() call
269 */
270int
271iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
272{
273	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
274
275	/* a slave must have been started for writing */
276	if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
277		return (IIC_ESTATUS);
278
279	return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
280}
281
282/*
283 * iicbus_read()
284 *
285 * Read a block of data from the slave previously started by
286 * iicbus_read() call
287 */
288int
289iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
290{
291	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
292
293	/* a slave must have been started for reading */
294	if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
295		return (IIC_ESTATUS);
296
297	return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
298}
299
300/*
301 * iicbus_write_byte()
302 *
303 * Write a byte to the slave previously started by iicbus_start() call
304 */
305int
306iicbus_write_byte(device_t bus, char byte, int timeout)
307{
308	struct iicbus_softc *sc = device_get_softc(bus);
309	char data = byte;
310	int sent;
311
312	/* a slave must have been started for writing */
313	if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
314		return (IIC_ESTATUS);
315
316	return (iicbus_write(bus, &data, 1, &sent, timeout));
317}
318
319/*
320 * iicbus_read_byte()
321 *
322 * Read a byte from the slave previously started by iicbus_start() call
323 */
324int
325iicbus_read_byte(device_t bus, char *byte, int timeout)
326{
327	struct iicbus_softc *sc = device_get_softc(bus);
328	int read;
329
330	/* a slave must have been started for reading */
331	if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
332		return (IIC_ESTATUS);
333
334	return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
335}
336
337/*
338 * iicbus_block_write()
339 *
340 * Write a block of data to slave ; start/stop protocol managed
341 */
342int
343iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
344{
345	u_char addr = slave & ~LSB;
346	int error;
347
348	if ((error = iicbus_start(bus, addr, 0)))
349		return (error);
350
351	error = iicbus_write(bus, buf, len, sent, 0);
352
353	iicbus_stop(bus);
354
355	return (error);
356}
357
358/*
359 * iicbus_block_read()
360 *
361 * Read a block of data from slave ; start/stop protocol managed
362 */
363int
364iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
365{
366	u_char addr = slave | LSB;
367	int error;
368
369	if ((error = iicbus_start(bus, addr, 0)))
370		return (error);
371
372	error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
373
374	iicbus_stop(bus);
375
376	return (error);
377}
378
379/*
380 * iicbus_transfer()
381 *
382 * Do an aribtrary number of transfers on the iicbus.  We pass these
383 * raw requests to the bridge driver.  If the bridge driver supports
384 * them directly, then it manages all the details.  If not, it can use
385 * the helper function iicbus_transfer_gen() which will do the
386 * transfers at a low level.
387 *
388 * Pointers passed in as part of iic_msg must be kernel pointers.
389 * Callers that have user addresses to manage must do so on their own.
390 */
391int
392iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
393{
394
395	return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
396}
397
398/*
399 * Generic version of iicbus_transfer that calls the appropriate
400 * routines to accomplish this.  See note above about acceptable
401 * buffer addresses.
402 */
403int
404iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
405{
406	int i, error, lenread, lenwrote, nkid, rpstart, addr;
407	device_t *children, bus;
408	bool nostop;
409
410	if ((error = device_get_children(dev, &children, &nkid)) != 0)
411		return (IIC_ERESOURCE);
412	if (nkid != 1) {
413		free(children, M_TEMP);
414		return (IIC_ENOTSUPP);
415	}
416	bus = children[0];
417	rpstart = 0;
418	free(children, M_TEMP);
419	nostop = iicbus_get_nostop(dev);
420	for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
421		addr = msgs[i].slave;
422		if (msgs[i].flags & IIC_M_RD)
423			addr |= LSB;
424		else
425			addr &= ~LSB;
426
427		if (!(msgs[i].flags & IIC_M_NOSTART)) {
428			if (rpstart)
429				error = iicbus_repeated_start(bus, addr, 0);
430			else
431				error = iicbus_start(bus, addr, 0);
432		}
433		if (error != 0)
434			break;
435
436		if (msgs[i].flags & IIC_M_RD)
437			error = iicbus_read(bus, msgs[i].buf, msgs[i].len,
438			    &lenread, IIC_LAST_READ, 0);
439		else
440			error = iicbus_write(bus, msgs[i].buf, msgs[i].len,
441			    &lenwrote, 0);
442		if (error != 0)
443			break;
444
445		if ((msgs[i].flags & IIC_M_NOSTOP) != 0 ||
446		    (nostop && i + 1 < nmsgs)) {
447			rpstart = 1;	/* Next message gets repeated start */
448		} else {
449			rpstart = 0;
450			iicbus_stop(bus);
451		}
452	}
453	if (error != 0 && !nostop)
454		iicbus_stop(bus);
455	return (error);
456}
457