xref: /freebsd/sys/dev/iicbus/iic.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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  * $FreeBSD$
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 
49 struct 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 
65 static int iic_probe(device_t);
66 static int iic_attach(device_t);
67 static int iic_detach(device_t);
68 static void iic_identify(driver_t *driver, device_t parent);
69 
70 static devclass_t iic_devclass;
71 
72 static 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 
85 static driver_t iic_driver = {
86 	"iic",
87 	iic_methods,
88 	sizeof(struct iic_softc),
89 };
90 
91 static	d_open_t	iicopen;
92 static	d_close_t	iicclose;
93 static	d_write_t	iicwrite;
94 static	d_read_t	iicread;
95 static	d_ioctl_t	iicioctl;
96 
97 static 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 
108 static void
109 iic_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", -1);
114 }
115 
116 static int
117 iic_probe(device_t dev)
118 {
119 	if (iicbus_get_addr(dev) > 0)
120 		return (ENXIO);
121 
122 	device_set_desc(dev, "I2C generic I/O");
123 
124 	return (0);
125 }
126 
127 static int
128 iic_attach(device_t dev)
129 {
130 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
131 
132 	sc->sc_dev = dev;
133 	sx_init(&sc->sc_lock, "iic");
134 	sc->sc_devnode = make_dev(&iic_cdevsw, device_get_unit(dev),
135 			UID_ROOT, GID_WHEEL,
136 			0600, "iic%d", device_get_unit(dev));
137 	if (sc->sc_devnode == NULL) {
138 		device_printf(dev, "failed to create character device\n");
139 		sx_destroy(&sc->sc_lock);
140 		return (ENXIO);
141 	}
142 	sc->sc_devnode->si_drv1 = sc;
143 
144 	return (0);
145 }
146 
147 static int
148 iic_detach(device_t dev)
149 {
150 	struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
151 
152 	if (sc->sc_devnode)
153 		destroy_dev(sc->sc_devnode);
154 	sx_destroy(&sc->sc_lock);
155 
156 	return (0);
157 }
158 
159 static int
160 iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
161 {
162 	struct iic_softc *sc = dev->si_drv1;
163 
164 	IIC_LOCK(sc);
165 	if (sc->sc_count > 0) {
166 		IIC_UNLOCK(sc);
167 		return (EBUSY);
168 	}
169 
170 	sc->sc_count++;
171 	IIC_UNLOCK(sc);
172 
173 	return (0);
174 }
175 
176 static int
177 iicclose(struct cdev *dev, int flags, int fmt, struct thread *td)
178 {
179 	struct iic_softc *sc = dev->si_drv1;
180 
181 	IIC_LOCK(sc);
182 	if (!sc->sc_count) {
183 		/* XXX: I don't think this can happen. */
184 		IIC_UNLOCK(sc);
185 		return (EINVAL);
186 	}
187 
188 	sc->sc_count--;
189 
190 	if (sc->sc_count < 0)
191 		panic("%s: iic_count < 0!", __func__);
192 	IIC_UNLOCK(sc);
193 
194 	return (0);
195 }
196 
197 static int
198 iicwrite(struct cdev *dev, struct uio * uio, int ioflag)
199 {
200 	struct iic_softc *sc = dev->si_drv1;
201 	device_t iicdev = sc->sc_dev;
202 	int sent, error, count;
203 
204 	IIC_LOCK(sc);
205 	if (!sc->sc_addr) {
206 		IIC_UNLOCK(sc);
207 		return (EINVAL);
208 	}
209 
210 	if (sc->sc_count == 0) {
211 		/* XXX: I don't think this can happen. */
212 		IIC_UNLOCK(sc);
213 		return (EINVAL);
214 	}
215 
216 	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
217 	    IIC_DONTWAIT);
218 	if (error) {
219 		IIC_UNLOCK(sc);
220 		return (error);
221 	}
222 
223 	count = min(uio->uio_resid, BUFSIZE);
224 	error = uiomove(sc->sc_buffer, count, uio);
225 	if (error) {
226 		IIC_UNLOCK(sc);
227 		return (error);
228 	}
229 
230 	error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
231 					sc->sc_buffer, count, &sent);
232 
233 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
234 	IIC_UNLOCK(sc);
235 
236 	return (error);
237 }
238 
239 static int
240 iicread(struct cdev *dev, struct uio * uio, int ioflag)
241 {
242 	struct iic_softc *sc = dev->si_drv1;
243 	device_t iicdev = sc->sc_dev;
244 	int len, error = 0;
245 	int bufsize;
246 
247 	IIC_LOCK(sc);
248 	if (!sc->sc_addr) {
249 		IIC_UNLOCK(sc);
250 		return (EINVAL);
251 	}
252 
253 	if (sc->sc_count == 0) {
254 		/* XXX: I don't think this can happen. */
255 		IIC_UNLOCK(sc);
256 		return (EINVAL);
257 	}
258 
259 	error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
260 	    IIC_DONTWAIT);
261 	if (error) {
262 		IIC_UNLOCK(sc);
263 		return (error);
264 	}
265 
266 	/* max amount of data to read */
267 	len = min(uio->uio_resid, BUFSIZE);
268 
269 	error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
270 	    sc->sc_inbuf, len, &bufsize);
271 	if (error) {
272 		IIC_UNLOCK(sc);
273 		return (error);
274 	}
275 
276 	if (bufsize > uio->uio_resid)
277 		panic("%s: too much data read!", __func__);
278 
279 	iicbus_release_bus(device_get_parent(iicdev), iicdev);
280 
281 	error = uiomove(sc->sc_inbuf, bufsize, uio);
282 	IIC_UNLOCK(sc);
283 	return (error);
284 }
285 
286 static int
287 iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
288 {
289 	struct iic_softc *sc = dev->si_drv1;
290 	device_t iicdev = sc->sc_dev;
291 	device_t parent = device_get_parent(iicdev);
292 	struct iiccmd *s = (struct iiccmd *)data;
293 	struct iic_rdwr_data *d = (struct iic_rdwr_data *)data;
294 	struct iic_msg *m;
295 	int error, count, i;
296 	char *buf = NULL;
297 	void **usrbufs = NULL;
298 
299 	if ((error = iicbus_request_bus(parent, iicdev,
300 	    (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR))))
301 		return (error);
302 
303 	switch (cmd) {
304 	case I2CSTART:
305 		IIC_LOCK(sc);
306 		error = iicbus_start(parent, s->slave, 0);
307 
308 		/*
309 		 * Implicitly set the chip addr to the slave addr passed as
310 		 * parameter. Consequently, start/stop shall be called before
311 		 * the read or the write of a block.
312 		 */
313 		if (!error)
314 			sc->sc_addr = s->slave;
315 		IIC_UNLOCK(sc);
316 
317 		break;
318 
319 	case I2CSTOP:
320 		error = iicbus_stop(parent);
321 		break;
322 
323 	case I2CRSTCARD:
324 		error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
325 		/*
326 		 * Ignore IIC_ENOADDR as it only means we have a master-only
327 		 * controller.
328 		 */
329 		if (error == IIC_ENOADDR)
330 			error = 0;
331 		break;
332 
333 	case I2CWRITE:
334 		if (s->count <= 0) {
335 			error = EINVAL;
336 			break;
337 		}
338 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
339 		error = copyin(s->buf, buf, s->count);
340 		if (error)
341 			break;
342 		error = iicbus_write(parent, buf, s->count, &count, 10);
343 		break;
344 
345 	case I2CREAD:
346 		if (s->count <= 0) {
347 			error = EINVAL;
348 			break;
349 		}
350 		buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK);
351 		error = iicbus_read(parent, buf, s->count, &count, s->last, 10);
352 		if (error)
353 			break;
354 		error = copyout(buf, s->buf, s->count);
355 		break;
356 
357 	case I2CRDWR:
358 		buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_TEMP, M_WAITOK);
359 		error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
360 		if (error)
361 			break;
362 		/* Alloc kernel buffers for userland data, copyin write data */
363 		usrbufs = malloc(sizeof(void *) * d->nmsgs, M_TEMP, M_ZERO | M_WAITOK);
364 		for (i = 0; i < d->nmsgs; i++) {
365 			m = &((struct iic_msg *)buf)[i];
366 			usrbufs[i] = m->buf;
367 			m->buf = malloc(m->len, M_TEMP, M_WAITOK);
368 			if (!(m->flags & IIC_M_RD))
369 				copyin(usrbufs[i], m->buf, m->len);
370 		}
371 		error = iicbus_transfer(iicdev, (struct iic_msg *)buf, d->nmsgs);
372 		/* Copyout all read segments, free up kernel buffers */
373 		for (i = 0; i < d->nmsgs; i++) {
374 			m = &((struct iic_msg *)buf)[i];
375 			if (m->flags & IIC_M_RD)
376 				copyout(m->buf, usrbufs[i], m->len);
377 			free(m->buf, M_TEMP);
378 		}
379 		free(usrbufs, M_TEMP);
380 		break;
381 
382 	case I2CRPTSTART:
383 		error = iicbus_repeated_start(parent, s->slave, 0);
384 		break;
385 
386 	default:
387 		error = ENOTTY;
388 	}
389 
390 	iicbus_release_bus(parent, iicdev);
391 
392 	if (buf != NULL)
393 		free(buf, M_TEMP);
394 	return (error);
395 }
396 
397 DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
398 MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
399 MODULE_VERSION(iic, 1);
400