iic.c revision 186833 
1/*-
2 * Copyright (c) 1998, 2001 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/iic.c 186833 2009-01-06 17:23:37Z nwhitehorn $
27 *
28 */
29#include <sys/param.h>
30#include <sys/bus.h>
31#include <sys/conf.h>
32#include <sys/fcntl.h>
33#include <sys/lock.h>
34#include <sys/kernel.h>
35#include <sys/malloc.h>
36#include <sys/module.h>
37#include <sys/sx.h>
38#include <sys/systm.h>
39#include <sys/uio.h>
40
41#include <dev/iicbus/iiconf.h>
42#include <dev/iicbus/iicbus.h>
43#include <dev/iicbus/iic.h>
44
45#include "iicbus_if.h"
46
47#define BUFSIZE 1024
48
49struct iic_softc {
50
51	device_t sc_dev;
52	u_char sc_addr;			/* 7 bit address on iicbus */
53	int sc_count;			/* >0 if device opened */
54
55	char sc_buffer[BUFSIZE];	/* output buffer */
56	char sc_inbuf[BUFSIZE];		/* input buffer */
57
58	struct cdev *sc_devnode;
59	struct sx sc_lock;
60};
61
62#define	IIC_LOCK(sc)			sx_xlock(&(sc)->sc_lock)
63#define	IIC_UNLOCK(sc)			sx_xunlock(&(sc)->sc_lock)
64
65static int iic_probe(device_t);
66static int iic_attach(device_t);
67static int iic_detach(device_t);
68static void iic_identify(driver_t *driver, device_t parent);
69
70static devclass_t iic_devclass;
71
72static device_method_t iic_methods[] = {
73	/* device interface */
74	DEVMETHOD(device_identify,	iic_identify),
75	DEVMETHOD(device_probe,		iic_probe),
76	DEVMETHOD(device_attach,	iic_attach),
77	DEVMETHOD(device_detach,	iic_detach),
78
79	/* iicbus interface */
80	DEVMETHOD(iicbus_intr,		iicbus_generic_intr),
81
82	{ 0, 0 }
83};
84
85static driver_t iic_driver = {
86	"iic",
87	iic_methods,
88	sizeof(struct iic_softc),
89};
90
91static	d_open_t	iicopen;
92static	d_close_t	iicclose;
93static	d_write_t	iicwrite;
94static	d_read_t	iicread;
95static	d_ioctl_t	iicioctl;
96
97static struct cdevsw iic_cdevsw = {
98	.d_version =	D_VERSION,
99	.d_flags =	D_TRACKCLOSE,
100	.d_open =	iicopen,
101	.d_close =	iicclose,
102	.d_read =	iicread,
103	.d_write =	iicwrite,
104	.d_ioctl =	iicioctl,
105	.d_name =	"iic",
106};
107
108static void
109iic_identify(driver_t *driver, device_t parent)
110{
111
112	if (device_find_child(parent, "iic", -1) == NULL)
113		BUS_ADD_CHILD(parent, 0, "iic", 0);
114}
115
116static int
117iic_probe(device_t dev)
118{
119	device_set_desc(dev, "I2C generic I/O");
120	return (BUS_PROBE_NOWILDCARD);
121}
122
123static int
124iic_attach(device_t dev)
125{
126	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
127
128	sc->sc_dev = dev;
129	sx_init(&sc->sc_lock, "iic");
130	sc->sc_devnode = make_dev(&iic_cdevsw, device_get_unit(dev),
131			UID_ROOT, GID_WHEEL,
132			0600, "iic%d", device_get_unit(dev));
133	if (sc->sc_devnode == NULL) {
134		device_printf(dev, "failed to create character device\n");
135		sx_destroy(&sc->sc_lock);
136		return (ENXIO);
137	}
138	sc->sc_devnode->si_drv1 = sc;
139
140	return (0);
141}
142
143static int
144iic_detach(device_t dev)
145{
146	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
147
148	if (sc->sc_devnode)
149		destroy_dev(sc->sc_devnode);
150	sx_destroy(&sc->sc_lock);
151
152	return (0);
153}
154
155static int
156iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
157{
158	struct iic_softc *sc = dev->si_drv1;
159
160	IIC_LOCK(sc);
161	if (sc->sc_count > 0) {
162		IIC_UNLOCK(sc);
163		return (EBUSY);
164	}
165
166	sc->sc_count++;
167	IIC_UNLOCK(sc);
168
169	return (0);
170}
171
172static int
173iicclose(struct cdev *dev, int flags, int fmt, struct thread *td)
174{
175	struct iic_softc *sc = dev->si_drv1;
176
177	IIC_LOCK(sc);
178	if (!sc->sc_count) {
179		/* XXX: I don't think this can happen. */
180		IIC_UNLOCK(sc);
181		return (EINVAL);
182	}
183
184	sc->sc_count--;
185
186	if (sc->sc_count < 0)
187		panic("%s: iic_count < 0!", __func__);
188	IIC_UNLOCK(sc);
189
190	return (0);
191}
192
193static int
194iicwrite(struct cdev *dev, struct uio * uio, int ioflag)
195{
196	struct iic_softc *sc = dev->si_drv1;
197	device_t iicdev = sc->sc_dev;
198	int sent, error, count;
199
200	IIC_LOCK(sc);
201	if (!sc->sc_addr) {
202		IIC_UNLOCK(sc);
203		return (EINVAL);
204	}
205
206	if (sc->sc_count == 0) {
207		/* XXX: I don't think this can happen. */
208		IIC_UNLOCK(sc);
209		return (EINVAL);
210	}
211
212	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
213	    IIC_DONTWAIT);
214	if (error) {
215		IIC_UNLOCK(sc);
216		return (error);
217	}
218
219	count = min(uio->uio_resid, BUFSIZE);
220	uiomove(sc->sc_buffer, count, uio);
221
222	error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
223					sc->sc_buffer, count, &sent);
224
225	iicbus_release_bus(device_get_parent(iicdev), iicdev);
226	IIC_UNLOCK(sc);
227
228	return (error);
229}
230
231static int
232iicread(struct cdev *dev, struct uio * uio, int ioflag)
233{
234	struct iic_softc *sc = dev->si_drv1;
235	device_t iicdev = sc->sc_dev;
236	int len, error = 0;
237	int bufsize;
238
239	IIC_LOCK(sc);
240	if (!sc->sc_addr) {
241		IIC_UNLOCK(sc);
242		return (EINVAL);
243	}
244
245	if (sc->sc_count == 0) {
246		/* XXX: I don't think this can happen. */
247		IIC_UNLOCK(sc);
248		return (EINVAL);
249	}
250
251	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
252	    IIC_DONTWAIT);
253	if (error) {
254		IIC_UNLOCK(sc);
255		return (error);
256	}
257
258	/* max amount of data to read */
259	len = min(uio->uio_resid, BUFSIZE);
260
261	error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
262	    sc->sc_inbuf, len, &bufsize);
263	if (error) {
264		IIC_UNLOCK(sc);
265		return (error);
266	}
267
268	if (bufsize > uio->uio_resid)
269		panic("%s: too much data read!", __func__);
270
271	iicbus_release_bus(device_get_parent(iicdev), iicdev);
272
273	error = uiomove(sc->sc_inbuf, bufsize, uio);
274	IIC_UNLOCK(sc);
275	return (error);
276}
277
278static int
279iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
280{
281	struct iic_softc *sc = dev->si_drv1;
282	device_t iicdev = sc->sc_dev;
283	device_t parent = device_get_parent(iicdev);
284	struct iiccmd *s = (struct iiccmd *)data;
285	struct iic_rdwr_data *d = (struct iic_rdwr_data *)data;
286	struct iic_msg *m;
287	int error, count, i;
288	char *buf = NULL;
289	void **usrbufs = NULL;
290
291	if ((error = iicbus_request_bus(parent, iicdev,
292	    (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR))))
293		return (error);
294
295	switch (cmd) {
296	case I2CSTART:
297		IIC_LOCK(sc);
298		error = iicbus_start(parent, s->slave, 0);
299
300		/*
301		 * Implicitly set the chip addr to the slave addr passed as
302		 * parameter. Consequently, start/stop shall be called before
303		 * the read or the write of a block.
304		 */
305		if (!error)
306			sc->sc_addr = s->slave;
307		IIC_UNLOCK(sc);
308
309		break;
310
311	case I2CSTOP:
312		error = iicbus_stop(parent);
313		break;
314
315	case I2CRSTCARD:
316		error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
317		break;
318
319	case I2CWRITE:
320		if (s->count <= 0) {
321			error = EINVAL;
322			break;
323		}
324		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
325		error = copyin(s->buf, buf, s->count);
326		if (error)
327			break;
328		error = iicbus_write(parent, buf, s->count, &count, 10);
329		break;
330
331	case I2CREAD:
332		if (s->count <= 0) {
333			error = EINVAL;
334			break;
335		}
336		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
337		error = iicbus_read(parent, buf, s->count, &count, s->last, 10);
338		if (error)
339			break;
340		error = copyout(buf, s->buf, s->count);
341		break;
342
343	case I2CRDWR:
344		buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_TEMP, M_WAITOK);
345		usrbufs = malloc(sizeof(void *) * d->nmsgs, M_TEMP, M_ZERO | M_WAITOK);
346		error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
347		if (error)
348			break;
349		/* Alloc kernel buffers for userland data, copyin write data */
350		for (i = 0; i < d->nmsgs; i++) {
351			m = &((struct iic_msg *)buf)[i];
352			usrbufs[i] = m->buf;
353			m->buf = malloc(m->len, M_TEMP, M_WAITOK);
354			if (!(m->flags & IIC_M_RD))
355				copyin(usrbufs[i], m->buf, m->len);
356		}
357		error = iicbus_transfer(iicdev, (struct iic_msg *)buf, d->nmsgs);
358		/* Copyout all read segments, free up kernel buffers */
359		for (i = 0; i < d->nmsgs; i++) {
360			m = &((struct iic_msg *)buf)[i];
361			if (m->flags & IIC_M_RD)
362				copyout(m->buf, usrbufs[i], m->len);
363			free(m->buf, M_TEMP);
364		}
365		free(usrbufs, M_TEMP);
366		break;
367	default:
368		error = ENOTTY;
369	}
370
371	iicbus_release_bus(parent, iicdev);
372
373	if (buf != NULL)
374		free(buf, M_TEMP);
375	return (error);
376}
377
378DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
379MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
380MODULE_VERSION(iic, 1);
381