1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1998, 2001 Nicolas Souchu
5 * Copyright (c) 2023 Juniper Networks, Inc.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 */
30 #include <sys/param.h>
31 #include <sys/abi_compat.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <sys/fcntl.h>
35 #include <sys/lock.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/sx.h>
40 #include <sys/systm.h>
41 #include <sys/uio.h>
42 #include <sys/errno.h>
43
44 #include <dev/iicbus/iiconf.h>
45 #include <dev/iicbus/iicbus.h>
46 #include <dev/iicbus/iic.h>
47
48 #include "iicbus_if.h"
49
50 struct iic_softc {
51 device_t sc_dev;
52 struct cdev *sc_devnode;
53 };
54
55 struct iic_cdevpriv {
56 struct sx lock;
57 struct iic_softc *sc;
58 bool started;
59 uint8_t addr;
60 };
61
62 #ifdef COMPAT_FREEBSD32
63 struct iic_msg32 {
64 uint16_t slave;
65 uint16_t flags;
66 uint16_t len;
67 uint32_t buf;
68 };
69
70 struct iiccmd32 {
71 u_char slave;
72 uint32_t count;
73 uint32_t last;
74 uint32_t buf;
75 };
76
77 struct iic_rdwr_data32 {
78 uint32_t msgs;
79 uint32_t nmsgs;
80 };
81
82 #define I2CWRITE32 _IOW('i', 4, struct iiccmd32)
83 #define I2CREAD32 _IOW('i', 5, struct iiccmd32)
84 #define I2CRDWR32 _IOW('i', 6, struct iic_rdwr_data32)
85 #endif
86
87 #define IIC_LOCK(cdp) sx_xlock(&(cdp)->lock)
88 #define IIC_UNLOCK(cdp) sx_xunlock(&(cdp)->lock)
89
90 static MALLOC_DEFINE(M_IIC, "iic", "I2C device data");
91
92 static int iic_probe(device_t);
93 static int iic_attach(device_t);
94 static int iic_detach(device_t);
95 static void iic_identify(driver_t *driver, device_t parent);
96 static void iicdtor(void *data);
97 static int iicuio_move(struct iic_cdevpriv *priv, struct uio *uio, int last);
98 static int iicuio(struct cdev *dev, struct uio *uio, int ioflag);
99 static int iicrdwr(struct iic_cdevpriv *priv, struct iic_rdwr_data *d, int flags, bool compat32);
100
101 static device_method_t iic_methods[] = {
102 /* device interface */
103 DEVMETHOD(device_identify, iic_identify),
104 DEVMETHOD(device_probe, iic_probe),
105 DEVMETHOD(device_attach, iic_attach),
106 DEVMETHOD(device_detach, iic_detach),
107
108 /* iicbus interface */
109 DEVMETHOD(iicbus_intr, iicbus_generic_intr),
110
111 { 0, 0 }
112 };
113
114 static driver_t iic_driver = {
115 "iic",
116 iic_methods,
117 sizeof(struct iic_softc),
118 };
119
120 static d_open_t iicopen;
121 static d_ioctl_t iicioctl;
122
123 static struct cdevsw iic_cdevsw = {
124 .d_version = D_VERSION,
125 .d_open = iicopen,
126 .d_read = iicuio,
127 .d_write = iicuio,
128 .d_ioctl = iicioctl,
129 .d_name = "iic",
130 };
131
132 static void
iic_identify(driver_t * driver,device_t parent)133 iic_identify(driver_t *driver, device_t parent)
134 {
135
136 if (device_find_child(parent, "iic", DEVICE_UNIT_ANY) == NULL)
137 BUS_ADD_CHILD(parent, 0, "iic", DEVICE_UNIT_ANY);
138 }
139
140 static int
iic_probe(device_t dev)141 iic_probe(device_t dev)
142 {
143 if (iicbus_get_addr(dev) > 0)
144 return (ENXIO);
145
146 device_set_desc(dev, "I2C generic I/O");
147
148 return (0);
149 }
150
151 static int
iic_attach(device_t dev)152 iic_attach(device_t dev)
153 {
154 struct iic_softc *sc;
155
156 sc = device_get_softc(dev);
157 sc->sc_dev = dev;
158 sc->sc_devnode = make_dev(&iic_cdevsw, device_get_unit(dev),
159 UID_ROOT, GID_WHEEL,
160 0600, "iic%d", device_get_unit(dev));
161 if (sc->sc_devnode == NULL) {
162 device_printf(dev, "failed to create character device\n");
163 return (ENXIO);
164 }
165 sc->sc_devnode->si_drv1 = sc;
166
167 return (0);
168 }
169
170 static int
iic_detach(device_t dev)171 iic_detach(device_t dev)
172 {
173 struct iic_softc *sc;
174
175 sc = device_get_softc(dev);
176
177 if (sc->sc_devnode)
178 destroy_dev(sc->sc_devnode);
179
180 return (0);
181 }
182
183 static int
iicopen(struct cdev * dev,int flags,int fmt,struct thread * td)184 iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
185 {
186 struct iic_cdevpriv *priv;
187 int error;
188
189 priv = malloc(sizeof(*priv), M_IIC, M_WAITOK | M_ZERO);
190
191 sx_init(&priv->lock, "iic");
192 priv->sc = dev->si_drv1;
193
194 error = devfs_set_cdevpriv(priv, iicdtor);
195 if (error != 0)
196 free(priv, M_IIC);
197
198 return (error);
199 }
200
201 static void
iicdtor(void * data)202 iicdtor(void *data)
203 {
204 device_t iicdev, parent;
205 struct iic_cdevpriv *priv;
206
207 priv = data;
208 KASSERT(priv != NULL, ("iic cdevpriv should not be NULL!"));
209
210 iicdev = priv->sc->sc_dev;
211 parent = device_get_parent(iicdev);
212
213 if (priv->started) {
214 iicbus_stop(parent);
215 iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
216 iicbus_release_bus(parent, iicdev);
217 }
218
219 sx_destroy(&priv->lock);
220 free(priv, M_IIC);
221 }
222
223 static int
iicuio_move(struct iic_cdevpriv * priv,struct uio * uio,int last)224 iicuio_move(struct iic_cdevpriv *priv, struct uio *uio, int last)
225 {
226 device_t parent;
227 int error, num_bytes, transferred_bytes, written_bytes;
228 char buffer[128];
229
230 parent = device_get_parent(priv->sc->sc_dev);
231 error = 0;
232
233 /*
234 * We can only transfer up to sizeof(buffer) bytes in 1 shot, so loop until
235 * everything has been transferred.
236 */
237 while ((error == 0) && (uio->uio_resid > 0)) {
238
239 num_bytes = MIN(uio->uio_resid, sizeof(buffer));
240 transferred_bytes = 0;
241
242 switch (uio->uio_rw) {
243 case UIO_WRITE:
244 error = uiomove(buffer, num_bytes, uio);
245
246 while ((error == 0) && (transferred_bytes < num_bytes)) {
247 written_bytes = 0;
248 error = iicbus_write(parent, &buffer[transferred_bytes],
249 num_bytes - transferred_bytes, &written_bytes, 0);
250 transferred_bytes += written_bytes;
251 }
252 break;
253 case UIO_READ:
254 error = iicbus_read(parent, buffer,
255 num_bytes, &transferred_bytes,
256 ((uio->uio_resid <= sizeof(buffer)) ? last : 0), 0);
257 if (error == 0)
258 error = uiomove(buffer, transferred_bytes, uio);
259 break;
260 }
261 }
262
263 return (error);
264 }
265
266 static int
iicuio(struct cdev * dev,struct uio * uio,int ioflag)267 iicuio(struct cdev *dev, struct uio *uio, int ioflag)
268 {
269 device_t parent;
270 struct iic_cdevpriv *priv;
271 int error;
272 uint8_t addr;
273
274 priv = NULL;
275 error = devfs_get_cdevpriv((void**)&priv);
276
277 if (error != 0)
278 return (error);
279 KASSERT(priv != NULL, ("iic cdevpriv should not be NULL!"));
280
281 IIC_LOCK(priv);
282 if (priv->started || (priv->addr == 0)) {
283 IIC_UNLOCK(priv);
284 return (ENXIO);
285 }
286 parent = device_get_parent(priv->sc->sc_dev);
287
288 error = iicbus_request_bus(parent, priv->sc->sc_dev,
289 (ioflag & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
290 if (error != 0) {
291 IIC_UNLOCK(priv);
292 return (error);
293 }
294
295 switch (uio->uio_rw) {
296 case UIO_READ:
297 addr = priv->addr | LSB;
298 break;
299 case UIO_WRITE:
300 addr = priv->addr & ~LSB;
301 break;
302 }
303
304 error = iicbus_start(parent, addr, 0);
305 if (error != 0)
306 {
307 iicbus_release_bus(parent, priv->sc->sc_dev);
308 IIC_UNLOCK(priv);
309 return (error);
310 }
311
312 error = iicuio_move(priv, uio, IIC_LAST_READ);
313
314 iicbus_stop(parent);
315 iicbus_release_bus(parent, priv->sc->sc_dev);
316 IIC_UNLOCK(priv);
317 return (error);
318 }
319
320 #ifdef COMPAT_FREEBSD32
321 static int
iic_copyinmsgs32(struct iic_rdwr_data * d,struct iic_msg * buf)322 iic_copyinmsgs32(struct iic_rdwr_data *d, struct iic_msg *buf)
323 {
324 struct iic_msg32 msg32;
325 struct iic_msg32 *m32;
326 int error, i;
327
328 m32 = (struct iic_msg32 *)d->msgs;
329 for (i = 0; i < d->nmsgs; i++) {
330 error = copyin(&m32[i], &msg32, sizeof(msg32));
331 if (error != 0)
332 return (error);
333 CP(msg32, buf[i], slave);
334 CP(msg32, buf[i], flags);
335 CP(msg32, buf[i], len);
336 PTRIN_CP(msg32, buf[i], buf);
337 }
338 return (0);
339 }
340 #endif
341
342 static int
iicrdwr(struct iic_cdevpriv * priv,struct iic_rdwr_data * d,int flags,bool compat32 __unused)343 iicrdwr(struct iic_cdevpriv *priv, struct iic_rdwr_data *d, int flags,
344 bool compat32 __unused)
345 {
346 #ifdef COMPAT_FREEBSD32
347 struct iic_rdwr_data dswab;
348 struct iic_rdwr_data32 *d32;
349 #endif
350 struct iic_msg *buf, *m;
351 void **usrbufs;
352 device_t iicdev, parent;
353 int error;
354 uint32_t i;
355
356 iicdev = priv->sc->sc_dev;
357 parent = device_get_parent(iicdev);
358 error = 0;
359 #ifdef COMPAT_FREEBSD32
360 if (compat32) {
361 d32 = (struct iic_rdwr_data32 *)d;
362 PTRIN_CP(*d32, dswab, msgs);
363 CP(*d32, dswab, nmsgs);
364 d = &dswab;
365 }
366 #endif
367
368 if (d->nmsgs > IIC_RDRW_MAX_MSGS)
369 return (EINVAL);
370
371 buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_IIC, M_WAITOK);
372
373 #ifdef COMPAT_FREEBSD32
374 if (compat32)
375 error = iic_copyinmsgs32(d, buf);
376 else
377 #endif
378 error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
379 if (error != 0) {
380 free(buf, M_IIC);
381 return (error);
382 }
383
384 /* Alloc kernel buffers for userland data, copyin write data */
385 usrbufs = malloc(sizeof(void *) * d->nmsgs, M_IIC, M_WAITOK | M_ZERO);
386
387 for (i = 0; i < d->nmsgs; i++) {
388 m = &(buf[i]);
389 usrbufs[i] = m->buf;
390
391 /*
392 * At least init the buffer to NULL so we can safely free() it later.
393 * If the copyin() to buf failed, don't try to malloc bogus m->len.
394 */
395 m->buf = NULL;
396 if (error != 0)
397 continue;
398
399 /* m->len is uint16_t, so allocation size is capped at 64K. */
400 m->buf = malloc(m->len, M_IIC, M_WAITOK);
401 if (!(m->flags & IIC_M_RD))
402 error = copyin(usrbufs[i], m->buf, m->len);
403 }
404
405 if (error == 0)
406 error = iicbus_request_bus(parent, iicdev,
407 (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
408
409 if (error == 0) {
410 error = iicbus_transfer(iicdev, buf, d->nmsgs);
411 iicbus_release_bus(parent, iicdev);
412 }
413
414 /* Copyout all read segments, free up kernel buffers */
415 for (i = 0; i < d->nmsgs; i++) {
416 m = &(buf[i]);
417 if ((error == 0) && (m->flags & IIC_M_RD))
418 error = copyout(m->buf, usrbufs[i], m->len);
419 free(m->buf, M_IIC);
420 }
421
422 free(usrbufs, M_IIC);
423 free(buf, M_IIC);
424 return (error);
425 }
426
427 static int
iicioctl(struct cdev * dev,u_long cmd,caddr_t data,int flags,struct thread * td)428 iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
429 {
430 #ifdef COMPAT_FREEBSD32
431 struct iiccmd iicswab;
432 #endif
433 device_t parent, iicdev;
434 struct iiccmd *s;
435 #ifdef COMPAT_FREEBSD32
436 struct iiccmd32 *s32;
437 #endif
438 struct uio ubuf;
439 struct iovec uvec;
440 struct iic_cdevpriv *priv;
441 int error;
442 bool compat32;
443
444 s = (struct iiccmd *)data;
445 #ifdef COMPAT_FREEBSD32
446 s32 = (struct iiccmd32 *)data;
447 #endif
448 error = devfs_get_cdevpriv((void**)&priv);
449 if (error != 0)
450 return (error);
451
452 KASSERT(priv != NULL, ("iic cdevpriv should not be NULL!"));
453
454 iicdev = priv->sc->sc_dev;
455 parent = device_get_parent(iicdev);
456 IIC_LOCK(priv);
457
458 #ifdef COMPAT_FREEBSD32
459 switch (cmd) {
460 case I2CWRITE32:
461 case I2CREAD32:
462 CP(*s32, iicswab, slave);
463 CP(*s32, iicswab, count);
464 CP(*s32, iicswab, last);
465 PTRIN_CP(*s32, iicswab, buf);
466 s = &iicswab;
467 break;
468 default:
469 break;
470 }
471 #endif
472
473 switch (cmd) {
474 case I2CSTART:
475 if (priv->started) {
476 error = EINVAL;
477 break;
478 }
479 error = iicbus_request_bus(parent, iicdev,
480 (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
481
482 if (error == 0)
483 error = iicbus_start(parent, s->slave, 0);
484
485 if (error == 0) {
486 priv->addr = s->slave;
487 priv->started = true;
488 } else
489 iicbus_release_bus(parent, iicdev);
490
491 break;
492
493 case I2CSTOP:
494 if (priv->started) {
495 error = iicbus_stop(parent);
496 iicbus_release_bus(parent, iicdev);
497 priv->started = false;
498 }
499
500 break;
501
502 case I2CRSTCARD:
503 /*
504 * Bus should be owned before we reset it.
505 * We allow the bus to be already owned as the result of an in-progress
506 * sequence; however, bus reset will always be followed by release
507 * (a new start is presumably needed for I/O anyway). */
508 if (!priv->started)
509 error = iicbus_request_bus(parent, iicdev,
510 (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR));
511
512 if (error == 0) {
513 error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
514 /*
515 * Ignore IIC_ENOADDR as it only means we have a master-only
516 * controller.
517 */
518 if (error == IIC_ENOADDR)
519 error = 0;
520
521 iicbus_release_bus(parent, iicdev);
522 priv->started = false;
523 }
524 break;
525
526 case I2CWRITE:
527 #ifdef COMPAT_FREEBSD32
528 case I2CWRITE32:
529 #endif
530 if (!priv->started) {
531 error = EINVAL;
532 break;
533 }
534 uvec.iov_base = s->buf;
535 uvec.iov_len = s->count;
536 ubuf.uio_iov = &uvec;
537 ubuf.uio_iovcnt = 1;
538 ubuf.uio_segflg = UIO_USERSPACE;
539 ubuf.uio_td = td;
540 ubuf.uio_resid = s->count;
541 ubuf.uio_offset = 0;
542 ubuf.uio_rw = UIO_WRITE;
543 error = iicuio_move(priv, &ubuf, 0);
544 break;
545
546 case I2CREAD:
547 #ifdef COMPAT_FREEBSD32
548 case I2CREAD32:
549 #endif
550 if (!priv->started) {
551 error = EINVAL;
552 break;
553 }
554 uvec.iov_base = s->buf;
555 uvec.iov_len = s->count;
556 ubuf.uio_iov = &uvec;
557 ubuf.uio_iovcnt = 1;
558 ubuf.uio_segflg = UIO_USERSPACE;
559 ubuf.uio_td = td;
560 ubuf.uio_resid = s->count;
561 ubuf.uio_offset = 0;
562 ubuf.uio_rw = UIO_READ;
563 error = iicuio_move(priv, &ubuf, s->last);
564 break;
565
566 #ifdef COMPAT_FREEBSD32
567 case I2CRDWR32:
568 #endif
569 case I2CRDWR:
570 /*
571 * The rdwr list should be a self-contained set of
572 * transactions. Fail if another transaction is in progress.
573 */
574 if (priv->started) {
575 error = EINVAL;
576 break;
577 }
578
579 #ifdef COMPAT_FREEBSD32
580 compat32 = (cmd == I2CRDWR32);
581 #else
582 compat32 = false;
583 #endif
584 error = iicrdwr(priv, (struct iic_rdwr_data *)data, flags,
585 compat32);
586
587 break;
588
589 case I2CRPTSTART:
590 if (!priv->started) {
591 error = EINVAL;
592 break;
593 }
594 error = iicbus_repeated_start(parent, s->slave, 0);
595 break;
596
597 case I2CSADDR:
598 priv->addr = *((uint8_t*)data);
599 break;
600
601 default:
602 error = ENOTTY;
603 }
604
605 IIC_UNLOCK(priv);
606 return (error);
607 }
608
609 DRIVER_MODULE(iic, iicbus, iic_driver, 0, 0);
610 MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
611 MODULE_VERSION(iic, 1);
612