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: stable/10/sys/dev/iicbus/iic.c 300948 2016-05-29 07:14:51Z jah $
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 #include <sys/errno.h>
41
42 #include <dev/iicbus/iiconf.h>
43 #include <dev/iicbus/iicbus.h>
44 #include <dev/iicbus/iic.h>
45
46 #include "iicbus_if.h"
47
48 struct iic_softc {
49 device_t sc_dev;
50 struct cdev *sc_devnode;
51 };
52
53 struct iic_cdevpriv {
54 struct sx lock;
55 struct iic_softc *sc;
56 bool started;
57 uint8_t addr;
58 };
59
60
61 #define IIC_LOCK(cdp) sx_xlock(&(cdp)->lock)
62 #define IIC_UNLOCK(cdp) sx_xunlock(&(cdp)->lock)
63
64 static MALLOC_DEFINE(M_IIC, "iic", "I2C device data");
65
66 static int iic_probe(device_t);
67 static int iic_attach(device_t);
68 static int iic_detach(device_t);
69 static void iic_identify(driver_t *driver, device_t parent);
70 static void iicdtor(void *data);
71 static int iicuio_move(struct iic_cdevpriv *priv, struct uio *uio, int last);
72 static int iicuio(struct cdev *dev, struct uio *uio, int ioflag);
73 static int iicrdwr(struct iic_cdevpriv *priv, struct iic_rdwr_data *d, int flags);
74
75 static devclass_t iic_devclass;
76
77 static device_method_t iic_methods[] = {
78 /* device interface */
79 DEVMETHOD(device_identify, iic_identify),
80 DEVMETHOD(device_probe, iic_probe),
81 DEVMETHOD(device_attach, iic_attach),
82 DEVMETHOD(device_detach, iic_detach),
83
84 /* iicbus interface */
85 DEVMETHOD(iicbus_intr, iicbus_generic_intr),
86
87 { 0, 0 }
88 };
89
90 static driver_t iic_driver = {
91 "iic",
92 iic_methods,
93 sizeof(struct iic_softc),
94 };
95
96 static d_open_t iicopen;
97 static d_ioctl_t iicioctl;
98
99 static struct cdevsw iic_cdevsw = {
100 .d_version = D_VERSION,
101 .d_open = iicopen,
102 .d_read = iicuio,
103 .d_write = iicuio,
104 .d_ioctl = iicioctl,
105 .d_name = "iic",
106 };
107
108 static void
iic_identify(driver_t * driver,device_t parent)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
iic_probe(device_t dev)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
iic_attach(device_t dev)128 iic_attach(device_t dev)
129 {
130 struct iic_softc *sc;
131
132 sc = device_get_softc(dev);
133 sc->sc_dev = dev;
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 return (ENXIO);
140 }
141 sc->sc_devnode->si_drv1 = sc;
142
143 return (0);
144 }
145
146 static int
iic_detach(device_t dev)147 iic_detach(device_t dev)
148 {
149 struct iic_softc *sc;
150
151 sc = device_get_softc(dev);
152
153 if (sc->sc_devnode)
154 destroy_dev(sc->sc_devnode);
155
156 return (0);
157 }
158
159 static int
iicopen(struct cdev * dev,int flags,int fmt,struct thread * td)160 iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
161 {
162 struct iic_cdevpriv *priv;
163 int error;
164
165 priv = malloc(sizeof(*priv), M_IIC, M_WAITOK | M_ZERO);
166
167 sx_init(&priv->lock, "iic");
168 priv->sc = dev->si_drv1;
169
170 error = devfs_set_cdevpriv(priv, iicdtor);
171 if (error != 0)
172 free(priv, M_IIC);
173
174 return (error);
175 }
176
177 static void
iicdtor(void * data)178 iicdtor(void *data)
179 {
180 device_t iicdev, parent;
181 struct iic_cdevpriv *priv;
182
183 priv = data;
184 KASSERT(priv != NULL, ("iic cdevpriv should not be NULL!"));
185
186 iicdev = priv->sc->sc_dev;
187 parent = device_get_parent(iicdev);
188
189 if (priv->started) {
190 iicbus_stop(parent);
191 iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
192 iicbus_release_bus(parent, iicdev);
193 }
194
195 sx_destroy(&priv->lock);
196 free(priv, M_IIC);
197 }
198
199 static int
iicuio_move(struct iic_cdevpriv * priv,struct uio * uio,int last)200 iicuio_move(struct iic_cdevpriv *priv, struct uio *uio, int last)
201 {
202 device_t parent;
203 int error, num_bytes, transferred_bytes, written_bytes;
204 char buffer[128];
205
206 parent = device_get_parent(priv->sc->sc_dev);
207 error = 0;
208
209 /*
210 * We can only transfer up to sizeof(buffer) bytes in 1 shot, so loop until
211 * everything has been transferred.
212 */
213 while ((error == 0) && (uio->uio_resid > 0)) {
214
215 num_bytes = MIN(uio->uio_resid, sizeof(buffer));
216 transferred_bytes = 0;
217
218 if (uio->uio_rw == UIO_WRITE) {
219 error = uiomove(buffer, num_bytes, uio);
220
221 while ((error == 0) && (transferred_bytes < num_bytes)) {
222 written_bytes = 0;
223 error = iicbus_write(parent, &buffer[transferred_bytes],
224 num_bytes - transferred_bytes, &written_bytes, 0);
225 transferred_bytes += written_bytes;
226 }
227
228 } else if (uio->uio_rw == UIO_READ) {
229 error = iicbus_read(parent, buffer,
230 num_bytes, &transferred_bytes,
231 ((uio->uio_resid <= sizeof(buffer)) ? last : 0), 0);
232 if (error == 0)
233 error = uiomove(buffer, transferred_bytes, uio);
234 }
235 }
236
237 return (error);
238 }
239
240 static int
iicuio(struct cdev * dev,struct uio * uio,int ioflag)241 iicuio(struct cdev *dev, struct uio *uio, int ioflag)
242 {
243 device_t parent;
244 struct iic_cdevpriv *priv;
245 int error;
246 uint8_t addr;
247
248 priv = NULL;
249 error = devfs_get_cdevpriv((void**)&priv);
250
251 if (error != 0)
252 return (error);
253 KASSERT(priv != NULL, ("iic cdevpriv should not be NULL!"));
254
255 IIC_LOCK(priv);
256 if (priv->started || (priv->addr == 0)) {
257 IIC_UNLOCK(priv);
258 return (ENXIO);
259 }
260 parent = device_get_parent(priv->sc->sc_dev);
261
262 error = iicbus_request_bus(parent, priv->sc->sc_dev,
263 (ioflag & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
264 if (error != 0) {
265 IIC_UNLOCK(priv);
266 return (error);
267 }
268
269 if (uio->uio_rw == UIO_READ)
270 addr = priv->addr | LSB;
271 else
272 addr = priv->addr & ~LSB;
273
274 error = iicbus_start(parent, addr, 0);
275 if (error != 0)
276 {
277 iicbus_release_bus(parent, priv->sc->sc_dev);
278 IIC_UNLOCK(priv);
279 return (error);
280 }
281
282 error = iicuio_move(priv, uio, IIC_LAST_READ);
283
284 iicbus_stop(parent);
285 iicbus_release_bus(parent, priv->sc->sc_dev);
286 IIC_UNLOCK(priv);
287 return (error);
288 }
289
290 static int
iicrdwr(struct iic_cdevpriv * priv,struct iic_rdwr_data * d,int flags)291 iicrdwr(struct iic_cdevpriv *priv, struct iic_rdwr_data *d, int flags)
292 {
293 struct iic_msg *buf, *m;
294 void **usrbufs;
295 device_t iicdev, parent;
296 int error, i;
297
298 iicdev = priv->sc->sc_dev;
299 parent = device_get_parent(iicdev);
300 error = 0;
301
302 if (d->nmsgs > IIC_RDRW_MAX_MSGS)
303 return (EINVAL);
304
305 buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_IIC, M_WAITOK);
306
307 error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
308 if (error != 0) {
309 free(buf, M_IIC);
310 return (error);
311 }
312
313 /* Alloc kernel buffers for userland data, copyin write data */
314 usrbufs = malloc(sizeof(void *) * d->nmsgs, M_IIC, M_WAITOK | M_ZERO);
315
316 for (i = 0; i < d->nmsgs; i++) {
317 m = &(buf[i]);
318 usrbufs[i] = m->buf;
319
320 /*
321 * At least init the buffer to NULL so we can safely free() it later.
322 * If the copyin() to buf failed, don't try to malloc bogus m->len.
323 */
324 m->buf = NULL;
325 if (error != 0)
326 continue;
327
328 /* m->len is uint16_t, so allocation size is capped at 64K. */
329 m->buf = malloc(m->len, M_IIC, M_WAITOK);
330 if (!(m->flags & IIC_M_RD))
331 error = copyin(usrbufs[i], m->buf, m->len);
332 }
333
334 if (error == 0)
335 error = iicbus_request_bus(parent, iicdev,
336 (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
337
338 if (error == 0) {
339 error = iicbus_transfer(iicdev, buf, d->nmsgs);
340 iicbus_release_bus(parent, iicdev);
341 }
342
343 /* Copyout all read segments, free up kernel buffers */
344 for (i = 0; i < d->nmsgs; i++) {
345 m = &(buf[i]);
346 if ((error == 0) && (m->flags & IIC_M_RD))
347 error = copyout(m->buf, usrbufs[i], m->len);
348 free(m->buf, M_IIC);
349 }
350
351 free(usrbufs, M_IIC);
352 free(buf, M_IIC);
353 return (error);
354 }
355
356 static int
iicioctl(struct cdev * dev,u_long cmd,caddr_t data,int flags,struct thread * td)357 iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
358 {
359 device_t parent, iicdev;
360 struct iiccmd *s;
361 struct uio ubuf;
362 struct iovec uvec;
363 struct iic_cdevpriv *priv;
364 int error;
365
366 s = (struct iiccmd *)data;
367 error = devfs_get_cdevpriv((void**)&priv);
368 if (error != 0)
369 return (error);
370
371 KASSERT(priv != NULL, ("iic cdevpriv should not be NULL!"));
372
373 iicdev = priv->sc->sc_dev;
374 parent = device_get_parent(iicdev);
375 IIC_LOCK(priv);
376
377
378 switch (cmd) {
379 case I2CSTART:
380 if (priv->started) {
381 error = EINVAL;
382 break;
383 }
384 error = iicbus_request_bus(parent, iicdev,
385 (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
386
387 if (error == 0)
388 error = iicbus_start(parent, s->slave, 0);
389
390 if (error == 0) {
391 priv->addr = s->slave;
392 priv->started = true;
393 } else
394 iicbus_release_bus(parent, iicdev);
395
396 break;
397
398 case I2CSTOP:
399 if (priv->started) {
400 error = iicbus_stop(parent);
401 iicbus_release_bus(parent, iicdev);
402 priv->started = false;
403 }
404
405 break;
406
407 case I2CRSTCARD:
408 /*
409 * Bus should be owned before we reset it.
410 * We allow the bus to be already owned as the result of an in-progress
411 * sequence; however, bus reset will always be followed by release
412 * (a new start is presumably needed for I/O anyway). */
413 if (!priv->started)
414 error = iicbus_request_bus(parent, iicdev,
415 (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
416
417 if (error == 0) {
418 error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
419 /*
420 * Ignore IIC_ENOADDR as it only means we have a master-only
421 * controller.
422 */
423 if (error == IIC_ENOADDR)
424 error = 0;
425
426 iicbus_release_bus(parent, iicdev);
427 priv->started = false;
428 }
429 break;
430
431 case I2CWRITE:
432 if (!priv->started) {
433 error = EINVAL;
434 break;
435 }
436 uvec.iov_base = s->buf;
437 uvec.iov_len = s->count;
438 ubuf.uio_iov = &uvec;
439 ubuf.uio_iovcnt = 1;
440 ubuf.uio_segflg = UIO_USERSPACE;
441 ubuf.uio_td = td;
442 ubuf.uio_resid = s->count;
443 ubuf.uio_offset = 0;
444 ubuf.uio_rw = UIO_WRITE;
445 error = iicuio_move(priv, &ubuf, 0);
446 break;
447
448 case I2CREAD:
449 if (!priv->started) {
450 error = EINVAL;
451 break;
452 }
453 uvec.iov_base = s->buf;
454 uvec.iov_len = s->count;
455 ubuf.uio_iov = &uvec;
456 ubuf.uio_iovcnt = 1;
457 ubuf.uio_segflg = UIO_USERSPACE;
458 ubuf.uio_td = td;
459 ubuf.uio_resid = s->count;
460 ubuf.uio_offset = 0;
461 ubuf.uio_rw = UIO_READ;
462 error = iicuio_move(priv, &ubuf, s->last);
463 break;
464
465 case I2CRDWR:
466 /*
467 * The rdwr list should be a self-contained set of
468 * transactions. Fail if another transaction is in progress.
469 */
470 if (priv->started) {
471 error = EINVAL;
472 break;
473 }
474
475 error = iicrdwr(priv, (struct iic_rdwr_data *)data, flags);
476
477 break;
478
479 case I2CRPTSTART:
480 if (!priv->started) {
481 error = EINVAL;
482 break;
483 }
484 error = iicbus_repeated_start(parent, s->slave, 0);
485 break;
486
487 case I2CSADDR:
488 priv->addr = *((uint8_t*)data);
489 break;
490
491 default:
492 error = ENOTTY;
493 }
494
495 IIC_UNLOCK(priv);
496 return (error);
497 }
498
499 DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
500 MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
501 MODULE_VERSION(iic, 1);
502