1 /*-
2 * Copyright (c) 1998 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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: stable/10/sys/dev/iicbus/iiconf.c 294673 2016-01-24 18:54:11Z ian $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/lock.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
35 #include <sys/mutex.h>
36 #include <sys/bus.h>
37
38 #include <dev/iicbus/iiconf.h>
39 #include <dev/iicbus/iicbus.h>
40 #include "iicbus_if.h"
41
42 /*
43 * Translate IIC_Exxxxx status values to vaguely-equivelent errno values.
44 */
45 int
iic2errno(int iic_status)46 iic2errno(int iic_status)
47 {
48 switch (iic_status) {
49 case IIC_NOERR: return (0);
50 case IIC_EBUSERR: return (EALREADY);
51 case IIC_ENOACK: return (EIO);
52 case IIC_ETIMEOUT: return (ETIMEDOUT);
53 case IIC_EBUSBSY: return (EWOULDBLOCK);
54 case IIC_ESTATUS: return (EPROTO);
55 case IIC_EUNDERFLOW: return (EIO);
56 case IIC_EOVERFLOW: return (EOVERFLOW);
57 case IIC_ENOTSUPP: return (EOPNOTSUPP);
58 case IIC_ENOADDR: return (EADDRNOTAVAIL);
59 case IIC_ERESOURCE: return (ENOMEM);
60 default: return (EIO);
61 }
62 }
63
64 /*
65 * iicbus_intr()
66 */
67 void
iicbus_intr(device_t bus,int event,char * buf)68 iicbus_intr(device_t bus, int event, char *buf)
69 {
70 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
71
72 /* call owner's intr routine */
73 if (sc->owner)
74 IICBUS_INTR(sc->owner, event, buf);
75
76 return;
77 }
78
79 static int
iicbus_poll(struct iicbus_softc * sc,int how)80 iicbus_poll(struct iicbus_softc *sc, int how)
81 {
82 int error;
83
84 IICBUS_ASSERT_LOCKED(sc);
85 switch (how) {
86 case IIC_WAIT | IIC_INTR:
87 error = mtx_sleep(sc, &sc->lock, IICPRI|PCATCH, "iicreq", 0);
88 break;
89
90 case IIC_WAIT | IIC_NOINTR:
91 error = mtx_sleep(sc, &sc->lock, IICPRI, "iicreq", 0);
92 break;
93
94 default:
95 return (IIC_EBUSBSY);
96 }
97
98 return (error);
99 }
100
101 /*
102 * iicbus_request_bus()
103 *
104 * Allocate the device to perform transfers.
105 *
106 * how : IIC_WAIT or IIC_DONTWAIT
107 */
108 int
iicbus_request_bus(device_t bus,device_t dev,int how)109 iicbus_request_bus(device_t bus, device_t dev, int how)
110 {
111 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
112 int error = 0;
113
114 IICBUS_LOCK(sc);
115
116 while ((error == 0) && (sc->owner != NULL))
117 error = iicbus_poll(sc, how);
118
119 if (error == 0) {
120 sc->owner = dev;
121 /*
122 * Drop the lock around the call to the bus driver.
123 * This call should be allowed to sleep in the IIC_WAIT case.
124 * Drivers might also need to grab locks that would cause LOR
125 * if our lock is held.
126 */
127 IICBUS_UNLOCK(sc);
128 /* Ask the underlying layers if the request is ok */
129 error = IICBUS_CALLBACK(device_get_parent(bus),
130 IIC_REQUEST_BUS, (caddr_t)&how);
131 IICBUS_LOCK(sc);
132
133 if (error != 0) {
134 sc->owner = NULL;
135 wakeup_one(sc);
136 }
137 }
138
139
140 IICBUS_UNLOCK(sc);
141
142 return (error);
143 }
144
145 /*
146 * iicbus_release_bus()
147 *
148 * Release the device allocated with iicbus_request_dev()
149 */
150 int
iicbus_release_bus(device_t bus,device_t dev)151 iicbus_release_bus(device_t bus, device_t dev)
152 {
153 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
154 int error;
155
156 IICBUS_LOCK(sc);
157
158 if (sc->owner != dev) {
159 IICBUS_UNLOCK(sc);
160 return (IIC_EBUSBSY);
161 }
162
163 /*
164 * Drop the lock around the call to the bus driver.
165 * This call should be allowed to sleep in the IIC_WAIT case.
166 * Drivers might also need to grab locks that would cause LOR
167 * if our lock is held.
168 */
169 IICBUS_UNLOCK(sc);
170 /* Ask the underlying layers if the release is ok */
171 error = IICBUS_CALLBACK(device_get_parent(bus), IIC_RELEASE_BUS, NULL);
172
173 if (error == 0) {
174 IICBUS_LOCK(sc);
175 sc->owner = NULL;
176
177 /* wakeup a waiting thread */
178 wakeup_one(sc);
179 IICBUS_UNLOCK(sc);
180 }
181
182 return (error);
183 }
184
185 /*
186 * iicbus_started()
187 *
188 * Test if the iicbus is started by the controller
189 */
190 int
iicbus_started(device_t bus)191 iicbus_started(device_t bus)
192 {
193 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
194
195 return (sc->started);
196 }
197
198 /*
199 * iicbus_start()
200 *
201 * Send start condition to the slave addressed by 'slave'
202 */
203 int
iicbus_start(device_t bus,u_char slave,int timeout)204 iicbus_start(device_t bus, u_char slave, int timeout)
205 {
206 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
207 int error = 0;
208
209 if (sc->started)
210 return (IIC_ESTATUS); /* protocol error, bus already started */
211
212 if (!(error = IICBUS_START(device_get_parent(bus), slave, timeout)))
213 sc->started = slave;
214 else
215 sc->started = 0;
216
217 return (error);
218 }
219
220 /*
221 * iicbus_repeated_start()
222 *
223 * Send start condition to the slave addressed by 'slave'
224 */
225 int
iicbus_repeated_start(device_t bus,u_char slave,int timeout)226 iicbus_repeated_start(device_t bus, u_char slave, int timeout)
227 {
228 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
229 int error = 0;
230
231 if (!sc->started)
232 return (IIC_ESTATUS); /* protocol error, bus not started */
233
234 if (!(error = IICBUS_REPEATED_START(device_get_parent(bus), slave, timeout)))
235 sc->started = slave;
236 else
237 sc->started = 0;
238
239 return (error);
240 }
241
242 /*
243 * iicbus_stop()
244 *
245 * Send stop condition to the bus
246 */
247 int
iicbus_stop(device_t bus)248 iicbus_stop(device_t bus)
249 {
250 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
251 int error = 0;
252
253 if (!sc->started)
254 return (IIC_ESTATUS); /* protocol error, bus not started */
255
256 error = IICBUS_STOP(device_get_parent(bus));
257
258 /* refuse any further access */
259 sc->started = 0;
260
261 return (error);
262 }
263
264 /*
265 * iicbus_write()
266 *
267 * Write a block of data to the slave previously started by
268 * iicbus_start() call
269 */
270 int
iicbus_write(device_t bus,const char * buf,int len,int * sent,int timeout)271 iicbus_write(device_t bus, const char *buf, int len, int *sent, int timeout)
272 {
273 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
274
275 /* a slave must have been started for writing */
276 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
277 return (IIC_ESTATUS);
278
279 return (IICBUS_WRITE(device_get_parent(bus), buf, len, sent, timeout));
280 }
281
282 /*
283 * iicbus_read()
284 *
285 * Read a block of data from the slave previously started by
286 * iicbus_read() call
287 */
288 int
iicbus_read(device_t bus,char * buf,int len,int * read,int last,int delay)289 iicbus_read(device_t bus, char *buf, int len, int *read, int last, int delay)
290 {
291 struct iicbus_softc *sc = (struct iicbus_softc *)device_get_softc(bus);
292
293 /* a slave must have been started for reading */
294 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
295 return (IIC_ESTATUS);
296
297 return (IICBUS_READ(device_get_parent(bus), buf, len, read, last, delay));
298 }
299
300 /*
301 * iicbus_write_byte()
302 *
303 * Write a byte to the slave previously started by iicbus_start() call
304 */
305 int
iicbus_write_byte(device_t bus,char byte,int timeout)306 iicbus_write_byte(device_t bus, char byte, int timeout)
307 {
308 struct iicbus_softc *sc = device_get_softc(bus);
309 char data = byte;
310 int sent;
311
312 /* a slave must have been started for writing */
313 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) != 0))
314 return (IIC_ESTATUS);
315
316 return (iicbus_write(bus, &data, 1, &sent, timeout));
317 }
318
319 /*
320 * iicbus_read_byte()
321 *
322 * Read a byte from the slave previously started by iicbus_start() call
323 */
324 int
iicbus_read_byte(device_t bus,char * byte,int timeout)325 iicbus_read_byte(device_t bus, char *byte, int timeout)
326 {
327 struct iicbus_softc *sc = device_get_softc(bus);
328 int read;
329
330 /* a slave must have been started for reading */
331 if (sc->started == 0 || (sc->strict != 0 && (sc->started & LSB) == 0))
332 return (IIC_ESTATUS);
333
334 return (iicbus_read(bus, byte, 1, &read, IIC_LAST_READ, timeout));
335 }
336
337 /*
338 * iicbus_block_write()
339 *
340 * Write a block of data to slave ; start/stop protocol managed
341 */
342 int
iicbus_block_write(device_t bus,u_char slave,char * buf,int len,int * sent)343 iicbus_block_write(device_t bus, u_char slave, char *buf, int len, int *sent)
344 {
345 u_char addr = slave & ~LSB;
346 int error;
347
348 if ((error = iicbus_start(bus, addr, 0)))
349 return (error);
350
351 error = iicbus_write(bus, buf, len, sent, 0);
352
353 iicbus_stop(bus);
354
355 return (error);
356 }
357
358 /*
359 * iicbus_block_read()
360 *
361 * Read a block of data from slave ; start/stop protocol managed
362 */
363 int
iicbus_block_read(device_t bus,u_char slave,char * buf,int len,int * read)364 iicbus_block_read(device_t bus, u_char slave, char *buf, int len, int *read)
365 {
366 u_char addr = slave | LSB;
367 int error;
368
369 if ((error = iicbus_start(bus, addr, 0)))
370 return (error);
371
372 error = iicbus_read(bus, buf, len, read, IIC_LAST_READ, 0);
373
374 iicbus_stop(bus);
375
376 return (error);
377 }
378
379 /*
380 * iicbus_transfer()
381 *
382 * Do an aribtrary number of transfers on the iicbus. We pass these
383 * raw requests to the bridge driver. If the bridge driver supports
384 * them directly, then it manages all the details. If not, it can use
385 * the helper function iicbus_transfer_gen() which will do the
386 * transfers at a low level.
387 *
388 * Pointers passed in as part of iic_msg must be kernel pointers.
389 * Callers that have user addresses to manage must do so on their own.
390 */
391 int
iicbus_transfer(device_t bus,struct iic_msg * msgs,uint32_t nmsgs)392 iicbus_transfer(device_t bus, struct iic_msg *msgs, uint32_t nmsgs)
393 {
394
395 return (IICBUS_TRANSFER(device_get_parent(bus), msgs, nmsgs));
396 }
397
398 int
iicbus_transfer_excl(device_t dev,struct iic_msg * msgs,uint32_t nmsgs,int how)399 iicbus_transfer_excl(device_t dev, struct iic_msg *msgs, uint32_t nmsgs,
400 int how)
401 {
402 device_t bus;
403 int error;
404
405 bus = device_get_parent(dev);
406 error = iicbus_request_bus(bus, dev, how);
407 if (error == 0)
408 error = IICBUS_TRANSFER(bus, msgs, nmsgs);
409 iicbus_release_bus(bus, dev);
410 return (error);
411 }
412
413 /*
414 * Generic version of iicbus_transfer that calls the appropriate
415 * routines to accomplish this. See note above about acceptable
416 * buffer addresses.
417 */
418 int
iicbus_transfer_gen(device_t dev,struct iic_msg * msgs,uint32_t nmsgs)419 iicbus_transfer_gen(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
420 {
421 int i, error, lenread, lenwrote, nkid, rpstart, addr;
422 device_t *children, bus;
423 bool nostop;
424
425 if ((error = device_get_children(dev, &children, &nkid)) != 0)
426 return (IIC_ERESOURCE);
427 if (nkid != 1) {
428 free(children, M_TEMP);
429 return (IIC_ENOTSUPP);
430 }
431 bus = children[0];
432 rpstart = 0;
433 free(children, M_TEMP);
434 nostop = iicbus_get_nostop(dev);
435 for (i = 0, error = 0; i < nmsgs && error == 0; i++) {
436 addr = msgs[i].slave;
437 if (msgs[i].flags & IIC_M_RD)
438 addr |= LSB;
439 else
440 addr &= ~LSB;
441
442 if (!(msgs[i].flags & IIC_M_NOSTART)) {
443 if (rpstart)
444 error = iicbus_repeated_start(bus, addr, 0);
445 else
446 error = iicbus_start(bus, addr, 0);
447 }
448 if (error != 0)
449 break;
450
451 if (msgs[i].flags & IIC_M_RD)
452 error = iicbus_read(bus, msgs[i].buf, msgs[i].len,
453 &lenread, IIC_LAST_READ, 0);
454 else
455 error = iicbus_write(bus, msgs[i].buf, msgs[i].len,
456 &lenwrote, 0);
457 if (error != 0)
458 break;
459
460 if ((msgs[i].flags & IIC_M_NOSTOP) != 0 ||
461 (nostop && i + 1 < nmsgs)) {
462 rpstart = 1; /* Next message gets repeated start */
463 } else {
464 rpstart = 0;
465 iicbus_stop(bus);
466 }
467 }
468 if (error != 0 && !nostop)
469 iicbus_stop(bus);
470 return (error);
471 }
472