1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1998 Nicolas Souchu
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <sys/bus.h>
39
40 #include <dev/iicbus/iiconf.h>
41 #include <dev/iicbus/iicbus.h>
42 #include "iicbus_if.h"
43
44 /*
45 * Translate IIC_Exxxxx status values to vaguely-equivelent errno values.
46 */
47 int
iic2errno(int iic_status)48 iic2errno(int iic_status)
49 {
50 switch (iic_status) {
51 case IIC_NOERR: return (0);
52 case IIC_EBUSERR: return (EALREADY);
53 case IIC_ENOACK: return (EIO);
54 case IIC_ETIMEOUT: return (ETIMEDOUT);
55 case IIC_EBUSBSY: return (EWOULDBLOCK);
56 case IIC_ESTATUS: return (EPROTO);
57 case IIC_EUNDERFLOW: return (EIO);
58 case IIC_EOVERFLOW: return (EOVERFLOW);
59 case IIC_ENOTSUPP: return (EOPNOTSUPP);
60 case IIC_ENOADDR: return (EADDRNOTAVAIL);
61 case IIC_ERESOURCE: return (ENOMEM);
62 default: return (EIO);
63 }
64 }
65
66 /*
67 * iicbus_intr()
68 */
69 void
iicbus_intr(device_t bus,int event,char * buf)70 iicbus_intr(device_t bus, int event, char *buf)
71 {
72 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
73
74 /* call owner's intr routine */
75 if (sc->owner)
76 IICBUS_INTR(sc->owner, event, buf);
77
78 return;
79 }
80
81 static int
iicbus_poll(struct iicbus_softc * sc,int how)82 iicbus_poll(struct iicbus_softc *sc, int how)
83 {
84 int error;
85
86 IICBUS_ASSERT_LOCKED(sc);
87 switch (how & IIC_INTRWAIT) {
88 case IIC_WAIT | IIC_INTR:
89 error = mtx_sleep(sc, &sc->lock, IICPRI|PCATCH, "iicreq", 0);
90 break;
91
92 case IIC_WAIT | IIC_NOINTR:
93 error = mtx_sleep(sc, &sc->lock, IICPRI, "iicreq", 0);
94 break;
95
96 default:
97 return (IIC_EBUSBSY);
98 }
99
100 return (error);
101 }
102
103 /*
104 * iicbus_request_bus()
105 *
106 * Allocate the device to perform transfers.
107 *
108 * how : IIC_WAIT or IIC_DONTWAIT
109 */
110 int
iicbus_request_bus(device_t bus,device_t dev,int how)111 iicbus_request_bus(device_t bus, device_t dev, int how)
112 {
113 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
114 int error = 0;
115
116 IICBUS_LOCK(sc);
117
118 for (;;) {
119 if (sc->owner == NULL)
120 break;
121 if ((how & IIC_RECURSIVE) && sc->owner == dev)
122 break;
123 if ((error = iicbus_poll(sc, how)) != 0)
124 break;
125 }
126
127 if (error == 0) {
128 ++sc->owncount;
129 if (sc->owner == NULL) {
130 sc->owner = dev;
131 /*
132 * Mark the device busy while it owns the bus, to
133 * prevent detaching the device, bus, or hardware
134 * controller, until ownership is relinquished. If the
135 * device is doing IO from its probe method before
136 * attaching, it cannot be busied; mark the bus busy.
137 */
138 if (device_get_state(dev) < DS_ATTACHING)
139 sc->busydev = bus;
140 else
141 sc->busydev = dev;
142 device_busy(sc->busydev);
143 /*
144 * Drop the lock around the call to the bus driver, it
145 * should be allowed to sleep in the IIC_WAIT case.
146 * Drivers might also need to grab locks that would
147 * cause a LOR if our lock is held.
148 */
149 IICBUS_UNLOCK(sc);
150 /* Ask the underlying layers if the request is ok */
151 error = IICBUS_CALLBACK(device_get_parent(bus),
152 IIC_REQUEST_BUS, (caddr_t)&how);
153 IICBUS_LOCK(sc);
154
155 if (error != 0) {
156 sc->owner = NULL;
157 sc->owncount = 0;
158 wakeup_one(sc);
159 device_unbusy(sc->busydev);
160 }
161 }
162 }
163
164 IICBUS_UNLOCK(sc);
165
166 return (error);
167 }
168
169 /*
170 * iicbus_release_bus()
171 *
172 * Release the device allocated with iicbus_request_dev()
173 */
174 int
iicbus_release_bus(device_t bus,device_t dev)175 iicbus_release_bus(device_t bus, device_t dev)
176 {
177 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
178
179 IICBUS_LOCK(sc);
180
181 if (sc->owner != dev) {
182 IICBUS_UNLOCK(sc);
183 return (IIC_EBUSBSY);
184 }
185
186 if (--sc->owncount == 0) {
187 /* Drop the lock while informing the low-level driver. */
188 IICBUS_UNLOCK(sc);
189 IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
190 IICBUS_LOCK(sc);
191 sc->owner = NULL;
192 wakeup_one(sc);
193 device_unbusy(sc->busydev);
194 }
195 IICBUS_UNLOCK(sc);
196 return (0);
197 }
198
199 /*
200 * iicbus_started()
201 *
202 * Test if the iicbus is started by the controller
203 */
204 int
iicbus_started(device_t bus)205 iicbus_started(device_t bus)
206 {
207 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
208
209 return (sc->started);
210 }
211
212 /*
213 * iicbus_start()
214 *
215 * Send start condition to the slave addressed by 'slave'
216 */
217 int
iicbus_start(device_t bus,u_char slave,int timeout)218 iicbus_start(device_t bus, u_char slave, int timeout)
219 {
220 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
221 int error = 0;
222
223 if (sc->started)
224 return (IIC_ESTATUS); /* protocol error, bus already started */
225
226 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
227 sc->started = slave;
228 else
229 sc->started = 0;
230
231 return (error);
232 }
233
234 /*
235 * iicbus_repeated_start()
236 *
237 * Send start condition to the slave addressed by 'slave'
238 */
239 int
iicbus_repeated_start(device_t bus,u_char slave,int timeout)240 iicbus_repeated_start(device_t bus, u_char slave, int timeout)
241 {
242 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
243 int error = 0;
244
245 if (!sc->started)
246 return (IIC_ESTATUS); /* protocol error, bus not started */
247
248 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
249 sc->started = slave;
250 else
251 sc->started = 0;
252
253 return (error);
254 }
255
256 /*
257 * iicbus_stop()
258 *
259 * Send stop condition to the bus
260 */
261 int
iicbus_stop(device_t bus)262 iicbus_stop(device_t bus)
263 {
264 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
265 int error = 0;
266
267 if (!sc->started)
268 return (IIC_ESTATUS); /* protocol error, bus not started */
269
270 error = IICBUS_STOP(device_get_parent(bus));
271
272 /* refuse any further access */
273 sc->started = 0;
274
275 return (error);
276 }
277
278 /*
279 * iicbus_write()
280 *
281 * Write a block of data to the slave previously started by
282 * iicbus_start() call
283 */
284 int
iicbus_write(device_t bus,const char * buf,int len,int * sent,int timeout)285 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
286 {
287 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
288
289 /* a slave must have been started for writing */
290 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
291 return (IIC_ESTATUS);
292
293 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
294 }
295
296 /*
297 * iicbus_read()
298 *
299 * Read a block of data from the slave previously started by
300 * iicbus_read() call
301 */
302 int
iicbus_read(device_t bus,char * buf,int len,int * read,int last,int delay)303 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
304 {
305 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
306
307 /* a slave must have been started for reading */
308 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
309 return (IIC_ESTATUS);
310
311 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
312 }
313
314 /*
315 * iicbus_write_byte()
316 *
317 * Write a byte to the slave previously started by iicbus_start() call
318 */
319 int
iicbus_write_byte(device_t bus,char byte,int timeout)320 iicbus_write_byte(device_t bus, char byte, int timeout)
321 {
322 struct iicbus_softc *sc = device_get_softc(bus);
323 char data = byte;
324 int sent;
325
326 /* a slave must have been started for writing */
327 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
328 return (IIC_ESTATUS);
329
330 return (iicbus_write(bus, &data, 1, &sent, timeout));
331 }
332
333 /*
334 * iicbus_read_byte()
335 *
336 * Read a byte from the slave previously started by iicbus_start() call
337 */
338 int
iicbus_read_byte(device_t bus,char * byte,int timeout)339 iicbus_read_byte(device_t bus, char *byte, int timeout)
340 {
341 struct iicbus_softc *sc = device_get_softc(bus);
342 int read;
343
344 /* a slave must have been started for reading */
345 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
346 return (IIC_ESTATUS);
347
348 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
349 }
350
351 /*
352 * iicbus_block_write()
353 *
354 * Write a block of data to slave ; start/stop protocol managed
355 */
356 int
iicbus_block_write(device_t bus,u_char slave,char * buf,int len,int * sent)357 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
358 {
359 u_char addr = slave & ~LSB;
360 int error;
361
362 if ((error = iicbus_start(bus, addr, 0)))
363 return (error);
364
365 error = iicbus_write(bus, buf, len, sent, 0);
366
367 iicbus_stop(bus);
368
369 return (error);
370 }
371
372 /*
373 * iicbus_block_read()
374 *
375 * Read a block of data from slave ; start/stop protocol managed
376 */
377 int
iicbus_block_read(device_t bus,u_char slave,char * buf,int len,int * read)378 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
379 {
380 u_char addr = slave | LSB;
381 int error;
382
383 if ((error = iicbus_start(bus, addr, 0)))
384 return (error);
385
386 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
387
388 iicbus_stop(bus);
389
390 return (error);
391 }
392
393 /*
394 * iicbus_transfer()
395 *
396 * Do an aribtrary number of transfers on the iicbus. We pass these
397 * raw requests to the bridge driver. If the bridge driver supports
398 * them directly, then it manages all the details. If not, it can use
399 * the helper function iicbus_transfer_gen() which will do the
400 * transfers at a low level.
401 *
402 * Pointers passed in as part of iic_msg must be kernel pointers.
403 * Callers that have user addresses to manage must do so on their own.
404 */
405 int
iicbus_transfer(device_t bus,struct iic_msg * msgs,uint32_t nmsgs)406 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
407 {
408
409 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
410 }
411
412 int
iicbus_transfer_excl(device_t dev,struct iic_msg * msgs,uint32_t nmsgs,int how)413 iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs,
414 int how)
415 {
416 device_t bus;
417 int error;
418
419 bus = device_get_parent(dev);
420 error = iicbus_request_bus(bus, dev, how);
421 if (error == 0)
422 error = IICBUS_TRANSFER(bus, msgs, nmsgs);
423 iicbus_release_bus(bus, dev);
424 return (error);
425 }
426
427 /*
428 * Generic version of iicbus_transfer that calls the appropriate
429 * routines to accomplish this. See note above about acceptable
430 * buffer addresses.
431 */
432 int
iicbus_transfer_gen(device_t dev,struct iic_msg * msgs,uint32_t nmsgs)433 iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
434 {
435 int i, error, lenread, lenwrote, nkid, rpstart, addr;
436 device_t *children, bus;
437 bool started;
438
439 if ((error = device_get_children(dev, &children, &nkid)) != 0)
440 return (IIC_ERESOURCE);
441 if (nkid != 1) {
442 free(children, M_TEMP);
443 return (IIC_ENOTSUPP);
444 }
445 bus = children[0];
446 rpstart = 0;
447 free(children, M_TEMP);
448 started = false;
449 for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
450 addr = msgs[i].slave;
451 if (msgs[i].flags & IIC_M_RD)
452 addr |= LSB;
453 else
454 addr &= ~LSB;
455
456 if (!(msgs[i].flags & IIC_M_NOSTART)) {
457 if (rpstart)
458 error = iicbus_repeated_start(bus, addr, 0);
459 else
460 error = iicbus_start(bus, addr, 0);
461 if (error != 0)
462 break;
463 started = true;
464 }
465
466 if (msgs[i].flags & IIC_M_RD)
467 error = iicbus_read(bus, msgs[i].buf, msgs[i].len,
468 &lenread, IIC_LAST_READ, 0);
469 else
470 error = iicbus_write(bus, msgs[i].buf, msgs[i].len,
471 &lenwrote, 0);
472 if (error != 0)
473 break;
474
475 if (!(msgs[i].flags & IIC_M_NOSTOP)) {
476 rpstart = 0;
477 iicbus_stop(bus);
478 } else {
479 rpstart = 1; /* Next message gets repeated start */
480 }
481 }
482 if (error != 0 && started)
483 iicbus_stop(bus);
484 return (error);
485 }
486
487 int
iicdev_readfrom(device_t slavedev,uint8_t regaddr,void * buffer,uint16_t buflen,int waithow)488 iicdev_readfrom(device_t slavedev, uint8_t regaddr, void *buffer,
489 uint16_t buflen, int waithow)
490 {
491 struct iic_msg msgs[2];
492 uint8_t slaveaddr;
493
494 /*
495 * Two transfers back to back with a repeat-start between them; first we
496 * write the address-within-device, then we read from the device.
497 */
498 slaveaddr = iicbus_get_addr(slavedev);
499
500 msgs[0].slave = slaveaddr;
501 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
502 msgs[0].len = 1;
503 msgs[0].buf = ®addr;
504
505 msgs[1].slave = slaveaddr;
506 msgs[1].flags = IIC_M_RD;
507 msgs[1].len = buflen;
508 msgs[1].buf = buffer;
509
510 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow));
511 }
512
iicdev_writeto(device_t slavedev,uint8_t regaddr,void * buffer,uint16_t buflen,int waithow)513 int iicdev_writeto(device_t slavedev, uint8_t regaddr, void *buffer,
514 uint16_t buflen, int waithow)
515 {
516 struct iic_msg msgs[2];
517 uint8_t slaveaddr;
518
519 /*
520 * Two transfers back to back with no stop or start between them; first
521 * we write the address then we write the data to that address, all in a
522 * single transfer from two scattered buffers.
523 */
524 slaveaddr = iicbus_get_addr(slavedev);
525
526 msgs[0].slave = slaveaddr;
527 msgs[0].flags = IIC_M_WR | IIC_M_NOSTOP;
528 msgs[0].len = 1;
529 msgs[0].buf = ®addr;
530
531 msgs[1].slave = slaveaddr;
532 msgs[1].flags = IIC_M_WR | IIC_M_NOSTART;
533 msgs[1].len = buflen;
534 msgs[1].buf = buffer;
535
536 return (iicbus_transfer_excl(slavedev, msgs, nitems(msgs), waithow));
537 }
538