iiconf.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/iiconf.c 50477 1999-08-28 01:08:13Z peter $
27 *
28 */
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/kernel.h>
32#include <sys/malloc.h>
33#include <sys/module.h>
34#include <sys/bus.h>
35
36#include <dev/iicbus/iiconf.h>
37#include <dev/iicbus/iicbus.h>
38#include "iicbus_if.h"
39
40/*
41 * iicbus_intr()
42 */
43void
44iicbus_intr(device_t bus, int event, char *buf)
45{
46	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
47
48	/* call owner's intr routine */
49	if (sc->owner)
50		IICBUS_INTR(sc->owner, event, buf);
51
52	return;
53}
54
55/*
56 * iicbus_alloc_bus()
57 *
58 * Allocate a new bus connected to the given parent device
59 */
60device_t
61iicbus_alloc_bus(device_t parent)
62{
63	device_t child;
64
65	/* add the bus to the parent */
66	child = device_add_child(parent, "iicbus", -1, NULL);
67
68	return (child);
69}
70
71static int
72iicbus_poll(struct iicbus_softc *sc, int how)
73{
74	int error;
75
76	switch (how) {
77	case (IIC_WAIT | IIC_INTR):
78		error = tsleep(sc, IICPRI|PCATCH, "iicreq", 0);
79		break;
80
81	case (IIC_WAIT | IIC_NOINTR):
82		error = tsleep(sc, IICPRI, "iicreq", 0);
83		break;
84
85	default:
86		return (EWOULDBLOCK);
87		break;
88	}
89
90	return (error);
91}
92
93/*
94 * iicbus_request_bus()
95 *
96 * Allocate the device to perform transfers.
97 *
98 * how	: IIC_WAIT or IIC_DONTWAIT
99 */
100int
101iicbus_request_bus(device_t bus, device_t dev, int how)
102{
103	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
104	int s, error = 0;
105
106	/* first, ask the underlying layers if the request is ok */
107	error = IICBUS_CALLBACK(device_get_parent(bus), IIC_REQUEST_BUS,
108				(caddr_t)&how);
109
110	while (!error) {
111		s = splhigh();
112		if (sc->owner && sc->owner != dev) {
113			splx(s);
114
115			error = iicbus_poll(sc, how);
116		} else {
117			sc->owner = dev;
118
119			splx(s);
120			return (0);
121		}
122
123		/* free any allocated resource */
124		if (error)
125			IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS,
126					(caddr_t)&how);
127	}
128
129	return (error);
130}
131
132/*
133 * iicbus_release_bus()
134 *
135 * Release the device allocated with iicbus_request_dev()
136 */
137int
138iicbus_release_bus(device_t bus, device_t dev)
139{
140	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
141	int s, error;
142
143	/* first, ask the underlying layers if the release is ok */
144	error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
145
146	if (error)
147		return (error);
148
149	s = splhigh();
150	if (sc->owner != dev) {
151		splx(s);
152		return (EACCES);
153	}
154
155	sc->owner = 0;
156	splx(s);
157
158	/* wakeup waiting processes */
159	wakeup(sc);
160
161	return (0);
162}
163
164/*
165 * iicbus_started()
166 *
167 * Test if the iicbus is started by the controller
168 */
169int
170iicbus_started(device_t bus)
171{
172	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
173
174	return (sc->started);
175}
176
177/*
178 * iicbus_start()
179 *
180 * Send start condition to the slave addressed by 'slave'
181 */
182int
183iicbus_start(device_t bus, u_char slave, int timeout)
184{
185	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
186	int error = 0;
187
188	if (sc->started)
189		return (EINVAL);		/* bus already started */
190
191	if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
192		sc->started = slave;
193	else
194		sc->started = 0;
195
196	return (error);
197}
198
199/*
200 * iicbus_repeated_start()
201 *
202 * Send start condition to the slave addressed by 'slave'
203 */
204int
205iicbus_repeated_start(device_t bus, u_char slave, int timeout)
206{
207	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
208	int error = 0;
209
210	if (!sc->started)
211		return (EINVAL);     /* bus should have been already started */
212
213	if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
214		sc->started = slave;
215	else
216		sc->started = 0;
217
218	return (error);
219}
220
221/*
222 * iicbus_stop()
223 *
224 * Send stop condition to the bus
225 */
226int
227iicbus_stop(device_t bus)
228{
229	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
230	int error = 0;
231
232	if (!sc->started)
233		return (EINVAL);		/* bus not started */
234
235	error = IICBUS_STOP(device_get_parent(bus));
236
237	/* refuse any further access */
238	sc->started = 0;
239
240	return (error);
241}
242
243/*
244 * iicbus_write()
245 *
246 * Write a block of data to the slave previously started by
247 * iicbus_start() call
248 */
249int
250iicbus_write(device_t bus, char *buf, int len, int *sent, int timeout)
251{
252	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
253
254	/* a slave must have been started with the appropriate address */
255	if (!sc->started || (sc->started & LSB))
256		return (EINVAL);
257
258	return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
259}
260
261/*
262 * iicbus_read()
263 *
264 * Read a block of data from the slave previously started by
265 * iicbus_read() call
266 */
267int
268iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
269{
270	struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
271
272	/* a slave must have been started with the appropriate address */
273	if (!sc->started || !(sc->started & LSB))
274		return (EINVAL);
275
276	return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
277}
278
279/*
280 * iicbus_write_byte()
281 *
282 * Write a byte to the slave previously started by iicbus_start() call
283 */
284int
285iicbus_write_byte(device_t bus, char byte, int timeout)
286{
287	char data = byte;
288	int sent;
289
290	return (iicbus_write(bus, &data, 1, &sent, timeout));
291}
292
293/*
294 * iicbus_read_byte()
295 *
296 * Read a byte from the slave previously started by iicbus_start() call
297 */
298int
299iicbus_read_byte(device_t bus, char *byte, int timeout)
300{
301	int read;
302
303	return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
304}
305
306/*
307 * iicbus_block_write()
308 *
309 * Write a block of data to slave ; start/stop protocol managed
310 */
311int
312iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
313{
314	u_char addr = slave & ~LSB;
315	int error;
316
317	if ((error = iicbus_start(bus, addr, 0)))
318		return (error);
319
320	error = iicbus_write(bus, buf, len, sent, 0);
321
322	iicbus_stop(bus);
323
324	return (error);
325}
326
327/*
328 * iicbus_block_read()
329 *
330 * Read a block of data from slave ; start/stop protocol managed
331 */
332int
333iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
334{
335	u_char addr = slave | LSB;
336	int error;
337
338	if ((error = iicbus_start(bus, addr, 0)))
339		return (error);
340
341	error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
342
343	iicbus_stop(bus);
344
345	return (error);
346}
347
348/*
349 * iicbus_get_addr()
350 *
351 * Get the I2C 7 bits address of the device
352 */
353u_char
354iicbus_get_addr(device_t dev)
355{
356	uintptr_t addr;
357	device_t parent = device_get_parent(dev);
358
359	BUS_READ_IVAR(parent, dev, IICBUS_IVAR_ADDR, &addr);
360
361	return ((u_char)addr);
362}
363
364