1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1998, 2001 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 /*
31 * I2C to SMB bridge
32 *
33 * Example:
34 *
35 * smb bttv
36 * \ /
37 * smbus
38 * / \
39 * iicsmb bti2c
40 * |
41 * iicbus
42 * / | \
43 * iicbb pcf ...
44 * |
45 * lpbb
46 */
47
48 #include <sys/param.h>
49 #include <sys/bus.h>
50 #include <sys/kernel.h>
51 #include <sys/lock.h>
52 #include <sys/module.h>
53 #include <sys/mutex.h>
54 #include <sys/systm.h>
55 #include <sys/uio.h>
56
57 #include <dev/iicbus/iiconf.h>
58 #include <dev/iicbus/iicbus.h>
59
60 #include <dev/smbus/smb.h>
61 #include <dev/smbus/smbconf.h>
62
63 #include "iicbus_if.h"
64 #include "smbus_if.h"
65
66 struct iicsmb_softc {
67
68 #define SMB_WAITING_ADDR 0x0
69 #define SMB_WAITING_LOW 0x1
70 #define SMB_WAITING_HIGH 0x2
71 #define SMB_DONE 0x3
72 int state;
73
74 u_char devaddr; /* slave device address */
75
76 char low; /* low byte received first */
77 char high; /* high byte */
78
79 struct mtx lock;
80 device_t smbus;
81 };
82
83 static int iicsmb_probe(device_t);
84 static int iicsmb_attach(device_t);
85 static int iicsmb_detach(device_t);
86 static void iicsmb_identify(driver_t *driver, device_t parent);
87
88 static int iicsmb_intr(device_t dev, int event, char *buf);
89 static int iicsmb_callback(device_t dev, int index, void *data);
90 static int iicsmb_quick(device_t dev, u_char slave, int how);
91 static int iicsmb_sendb(device_t dev, u_char slave, char byte);
92 static int iicsmb_recvb(device_t dev, u_char slave, char *byte);
93 static int iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte);
94 static int iicsmb_writew(device_t dev, u_char slave, char cmd, short word);
95 static int iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte);
96 static int iicsmb_readw(device_t dev, u_char slave, char cmd, short *word);
97 static int iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata);
98 static int iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf);
99 static int iicsmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf);
100
101 static device_method_t iicsmb_methods[] = {
102 /* device interface */
103 DEVMETHOD(device_identify, iicsmb_identify),
104 DEVMETHOD(device_probe, iicsmb_probe),
105 DEVMETHOD(device_attach, iicsmb_attach),
106 DEVMETHOD(device_detach, iicsmb_detach),
107
108 /* iicbus interface */
109 DEVMETHOD(iicbus_intr, iicsmb_intr),
110
111 /* smbus interface */
112 DEVMETHOD(smbus_callback, iicsmb_callback),
113 DEVMETHOD(smbus_quick, iicsmb_quick),
114 DEVMETHOD(smbus_sendb, iicsmb_sendb),
115 DEVMETHOD(smbus_recvb, iicsmb_recvb),
116 DEVMETHOD(smbus_writeb, iicsmb_writeb),
117 DEVMETHOD(smbus_writew, iicsmb_writew),
118 DEVMETHOD(smbus_readb, iicsmb_readb),
119 DEVMETHOD(smbus_readw, iicsmb_readw),
120 DEVMETHOD(smbus_pcall, iicsmb_pcall),
121 DEVMETHOD(smbus_bwrite, iicsmb_bwrite),
122 DEVMETHOD(smbus_bread, iicsmb_bread),
123
124 DEVMETHOD_END
125 };
126
127 static driver_t iicsmb_driver = {
128 "iicsmb",
129 iicsmb_methods,
130 sizeof(struct iicsmb_softc),
131 };
132
133 static void
iicsmb_identify(driver_t * driver,device_t parent)134 iicsmb_identify(driver_t *driver, device_t parent)
135 {
136
137 if (device_find_child(parent, "iicsmb", -1) == NULL)
138 BUS_ADD_CHILD(parent, 0, "iicsmb", DEVICE_UNIT_ANY);
139 }
140
141 static int
iicsmb_probe(device_t dev)142 iicsmb_probe(device_t dev)
143 {
144 device_set_desc(dev, "SMBus over I2C bridge");
145 return (BUS_PROBE_NOWILDCARD);
146 }
147
148 static int
iicsmb_attach(device_t dev)149 iicsmb_attach(device_t dev)
150 {
151 struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
152
153 mtx_init(&sc->lock, "iicsmb", NULL, MTX_DEF);
154
155 sc->smbus = device_add_child(dev, "smbus", DEVICE_UNIT_ANY);
156
157 /* probe and attach the smbus */
158 bus_attach_children(dev);
159
160 return (0);
161 }
162
163 static int
iicsmb_detach(device_t dev)164 iicsmb_detach(device_t dev)
165 {
166 struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
167
168 bus_generic_detach(dev);
169 mtx_destroy(&sc->lock);
170
171 return (0);
172 }
173
174 /*
175 * iicsmb_intr()
176 *
177 * iicbus interrupt handler
178 */
179 static int
iicsmb_intr(device_t dev,int event,char * buf)180 iicsmb_intr(device_t dev, int event, char *buf)
181 {
182 struct iicsmb_softc *sc = (struct iicsmb_softc *)device_get_softc(dev);
183
184 mtx_lock(&sc->lock);
185 switch (event) {
186 case INTR_GENERAL:
187 case INTR_START:
188 sc->state = SMB_WAITING_ADDR;
189 break;
190
191 case INTR_STOP:
192 /* call smbus intr handler */
193 smbus_intr(sc->smbus, sc->devaddr,
194 sc->low, sc->high, SMB_ENOERR);
195 break;
196
197 case INTR_RECEIVE:
198 switch (sc->state) {
199 case SMB_DONE:
200 /* XXX too much data, discard */
201 printf("%s: too much data from 0x%x\n", __func__,
202 sc->devaddr & 0xff);
203 goto end;
204
205 case SMB_WAITING_ADDR:
206 sc->devaddr = (u_char)*buf;
207 sc->state = SMB_WAITING_LOW;
208 break;
209
210 case SMB_WAITING_LOW:
211 sc->low = *buf;
212 sc->state = SMB_WAITING_HIGH;
213 break;
214
215 case SMB_WAITING_HIGH:
216 sc->high = *buf;
217 sc->state = SMB_DONE;
218 break;
219 }
220 end:
221 break;
222
223 case INTR_TRANSMIT:
224 case INTR_NOACK:
225 break;
226
227 case INTR_ERROR:
228 switch (*buf) {
229 case IIC_EBUSERR:
230 smbus_intr(sc->smbus, sc->devaddr, 0, 0, SMB_EBUSERR);
231 break;
232
233 default:
234 printf("%s unknown error 0x%x!\n", __func__,
235 (int)*buf);
236 break;
237 }
238 break;
239
240 default:
241 panic("%s: unknown event (%d)!", __func__, event);
242 }
243 mtx_unlock(&sc->lock);
244
245 return (0);
246 }
247
248 static int
iicsmb_callback(device_t dev,int index,void * data)249 iicsmb_callback(device_t dev, int index, void *data)
250 {
251 device_t parent = device_get_parent(dev);
252 int error = 0;
253 int how;
254
255 switch (index) {
256 case SMB_REQUEST_BUS:
257 /* request underlying iicbus */
258 how = *(int *)data;
259 error = iicbus_request_bus(parent, dev, how);
260 break;
261
262 case SMB_RELEASE_BUS:
263 /* release underlying iicbus */
264 error = iicbus_release_bus(parent, dev);
265 break;
266
267 default:
268 error = EINVAL;
269 }
270
271 return (error);
272 }
273
274 static int
iic2smb_error(int error)275 iic2smb_error(int error)
276 {
277 switch (error) {
278 case IIC_NOERR:
279 return (SMB_ENOERR);
280 case IIC_EBUSERR:
281 return (SMB_EBUSERR);
282 case IIC_ENOACK:
283 return (SMB_ENOACK);
284 case IIC_ETIMEOUT:
285 return (SMB_ETIMEOUT);
286 case IIC_EBUSBSY:
287 return (SMB_EBUSY);
288 case IIC_ESTATUS:
289 return (SMB_EBUSERR);
290 case IIC_EUNDERFLOW:
291 return (SMB_EBUSERR);
292 case IIC_EOVERFLOW:
293 return (SMB_EBUSERR);
294 case IIC_ENOTSUPP:
295 return (SMB_ENOTSUPP);
296 case IIC_ENOADDR:
297 return (SMB_EBUSERR);
298 case IIC_ERESOURCE:
299 return (SMB_EBUSERR);
300 default:
301 return (SMB_EBUSERR);
302 }
303 }
304
305 #define TRANSFER_MSGS(dev, msgs) iicbus_transfer(dev, msgs, nitems(msgs))
306
307 static int
iicsmb_quick(device_t dev,u_char slave,int how)308 iicsmb_quick(device_t dev, u_char slave, int how)
309 {
310 struct iic_msg msgs[] = {
311 { slave, how == SMB_QWRITE ? IIC_M_WR : IIC_M_RD, 0, NULL },
312 };
313 int error;
314
315 switch (how) {
316 case SMB_QWRITE:
317 case SMB_QREAD:
318 break;
319 default:
320 return (SMB_EINVAL);
321 }
322
323 error = TRANSFER_MSGS(dev, msgs);
324 return (iic2smb_error(error));
325 }
326
327 static int
iicsmb_sendb(device_t dev,u_char slave,char byte)328 iicsmb_sendb(device_t dev, u_char slave, char byte)
329 {
330 struct iic_msg msgs[] = {
331 { slave, IIC_M_WR, 1, &byte },
332 };
333 int error;
334
335 error = TRANSFER_MSGS(dev, msgs);
336 return (iic2smb_error(error));
337 }
338
339 static int
iicsmb_recvb(device_t dev,u_char slave,char * byte)340 iicsmb_recvb(device_t dev, u_char slave, char *byte)
341 {
342 struct iic_msg msgs[] = {
343 { slave, IIC_M_RD, 1, byte },
344 };
345 int error;
346
347 error = TRANSFER_MSGS(dev, msgs);
348 return (iic2smb_error(error));
349 }
350
351 static int
iicsmb_writeb(device_t dev,u_char slave,char cmd,char byte)352 iicsmb_writeb(device_t dev, u_char slave, char cmd, char byte)
353 {
354 uint8_t bytes[] = { cmd, byte };
355 struct iic_msg msgs[] = {
356 { slave, IIC_M_WR, nitems(bytes), bytes },
357 };
358 int error;
359
360 error = TRANSFER_MSGS(dev, msgs);
361 return (iic2smb_error(error));
362 }
363
364 static int
iicsmb_writew(device_t dev,u_char slave,char cmd,short word)365 iicsmb_writew(device_t dev, u_char slave, char cmd, short word)
366 {
367 uint8_t bytes[] = { cmd, word & 0xff, word >> 8 };
368 struct iic_msg msgs[] = {
369 { slave, IIC_M_WR, nitems(bytes), bytes },
370 };
371 int error;
372
373 error = TRANSFER_MSGS(dev, msgs);
374 return (iic2smb_error(error));
375 }
376
377 static int
iicsmb_readb(device_t dev,u_char slave,char cmd,char * byte)378 iicsmb_readb(device_t dev, u_char slave, char cmd, char *byte)
379 {
380 struct iic_msg msgs[] = {
381 { slave, IIC_M_WR | IIC_M_NOSTOP, 1, &cmd },
382 { slave, IIC_M_RD, 1, byte },
383 };
384 int error;
385
386 error = TRANSFER_MSGS(dev, msgs);
387 return (iic2smb_error(error));
388 }
389
390 static int
iicsmb_readw(device_t dev,u_char slave,char cmd,short * word)391 iicsmb_readw(device_t dev, u_char slave, char cmd, short *word)
392 {
393 uint8_t buf[2];
394 struct iic_msg msgs[] = {
395 { slave, IIC_M_WR | IIC_M_NOSTOP, 1, &cmd },
396 { slave, IIC_M_RD, nitems(buf), buf },
397 };
398 int error;
399
400 error = TRANSFER_MSGS(dev, msgs);
401 if (error == 0)
402 *word = ((uint16_t)buf[1] << 8) | buf[0];
403 return (iic2smb_error(error));
404 }
405
406 static int
iicsmb_pcall(device_t dev,u_char slave,char cmd,short sdata,short * rdata)407 iicsmb_pcall(device_t dev, u_char slave, char cmd, short sdata, short *rdata)
408 {
409 uint8_t in[3] = { cmd, sdata & 0xff, sdata >> 8 };
410 uint8_t out[2];
411 struct iic_msg msgs[] = {
412 { slave, IIC_M_WR | IIC_M_NOSTOP, nitems(in), in },
413 { slave, IIC_M_RD, nitems(out), out },
414 };
415 int error;
416
417 error = TRANSFER_MSGS(dev, msgs);
418 if (error == 0)
419 *rdata = ((uint16_t)out[1] << 8) | out[0];
420 return (iic2smb_error(error));
421 }
422
423 static int
iicsmb_bwrite(device_t dev,u_char slave,char cmd,u_char count,char * buf)424 iicsmb_bwrite(device_t dev, u_char slave, char cmd, u_char count, char *buf)
425 {
426 uint8_t bytes[2] = { cmd, count };
427 struct iic_msg msgs[] = {
428 { slave, IIC_M_WR | IIC_M_NOSTOP, nitems(bytes), bytes },
429 { slave, IIC_M_WR | IIC_M_NOSTART, count, buf },
430 };
431 int error;
432
433 if (count > SMB_MAXBLOCKSIZE || count == 0)
434 return (SMB_EINVAL);
435 error = TRANSFER_MSGS(dev, msgs);
436 return (iic2smb_error(error));
437 }
438
439 static int
iicsmb_bread(device_t dev,u_char slave,char cmd,u_char * count,char * buf)440 iicsmb_bread(device_t dev, u_char slave, char cmd, u_char *count, char *buf)
441 {
442 struct iic_msg msgs[] = {
443 { slave, IIC_M_WR | IIC_M_NOSTOP, 1, &cmd },
444 { slave, IIC_M_RD | IIC_M_NOSTOP, 1, count },
445 };
446 struct iic_msg block_msg[] = {
447 { slave, IIC_M_RD | IIC_M_NOSTART, 0, buf },
448 };
449 device_t parent = device_get_parent(dev);
450 int error;
451
452 /* Have to do this because the command is split in two transfers. */
453 error = iicbus_request_bus(parent, dev, IIC_WAIT | IIC_RECURSIVE);
454 if (error == 0)
455 error = TRANSFER_MSGS(dev, msgs);
456 if (error == 0) {
457 /*
458 * If the slave offers an empty or a too long reply,
459 * read one byte to generate the stop or abort.
460 */
461 if (*count > SMB_MAXBLOCKSIZE || *count == 0)
462 block_msg[0].len = 1;
463 else
464 block_msg[0].len = *count;
465 error = TRANSFER_MSGS(dev, block_msg);
466 if (*count > SMB_MAXBLOCKSIZE || *count == 0)
467 error = SMB_EINVAL;
468 }
469 (void)iicbus_release_bus(parent, dev);
470 return (iic2smb_error(error));
471 }
472
473 DRIVER_MODULE(iicsmb, iicbus, iicsmb_driver, 0, 0);
474 DRIVER_MODULE(smbus, iicsmb, smbus_driver, 0, 0);
475 MODULE_DEPEND(iicsmb, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
476 MODULE_DEPEND(iicsmb, smbus, SMBUS_MINVER, SMBUS_PREFVER, SMBUS_MAXVER);
477 MODULE_VERSION(iicsmb, 1);
478