xref: /netbsd-src/sys/dev/i2c/si70xx.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: si70xx.c,v 1.6 2020/12/05 14:50:33 jdc Exp $	*/
2 
3 /*
4  * Copyright (c) 2017 Brad Spencer <brad@anduin.eldar.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/cdefs.h>
20 __KERNEL_RCSID(0, "$NetBSD: si70xx.c,v 1.6 2020/12/05 14:50:33 jdc Exp $");
21 
22 /*
23   Driver for the Silicon Labs SI7013/SI7020/SI7021
24 */
25 
26 #include <sys/param.h>
27 #include <sys/systm.h>
28 #include <sys/kernel.h>
29 #include <sys/device.h>
30 #include <sys/module.h>
31 #include <sys/sysctl.h>
32 #include <sys/mutex.h>
33 
34 #include <dev/sysmon/sysmonvar.h>
35 #include <dev/i2c/i2cvar.h>
36 #include <dev/i2c/si70xxreg.h>
37 #include <dev/i2c/si70xxvar.h>
38 
39 
40 static uint8_t 	si70xx_crc(uint8_t *, size_t);
41 static int 	si70xx_poke(i2c_tag_t, i2c_addr_t, bool);
42 static int 	si70xx_match(device_t, cfdata_t, void *);
43 static void 	si70xx_attach(device_t, device_t, void *);
44 static int 	si70xx_detach(device_t, int);
45 static void 	si70xx_refresh(struct sysmon_envsys *, envsys_data_t *);
46 static int 	si70xx_update_status(struct si70xx_sc *);
47 static int 	si70xx_set_heateron(struct si70xx_sc *);
48 static int 	si70xx_set_resolution(struct si70xx_sc *, size_t);
49 static int 	si70xx_set_heatervalue(struct si70xx_sc *, size_t);
50 static int 	si70xx_verify_sysctl(SYSCTLFN_ARGS);
51 static int 	si70xx_verify_sysctl_resolution(SYSCTLFN_ARGS);
52 static int 	si70xx_verify_sysctl_heateron(SYSCTLFN_ARGS);
53 static int 	si70xx_verify_sysctl_heatervalue(SYSCTLFN_ARGS);
54 
55 #define SI70XX_DEBUG
56 #ifdef SI70XX_DEBUG
57 #define DPRINTF(s, l, x) \
58     do { \
59 	if (l <= s->sc_si70xxdebug) \
60 	    printf x; \
61     } while (/*CONSTCOND*/0)
62 #else
63 #define DPRINTF(s, l, x)
64 #endif
65 
66 CFATTACH_DECL_NEW(si70xxtemp, sizeof(struct si70xx_sc),
67     si70xx_match, si70xx_attach, si70xx_detach, NULL);
68 
69 static struct si70xx_sensor si70xx_sensors[] = {
70 	{
71 		.desc = "humidity",
72 		.type = ENVSYS_SRELHUMIDITY,
73 	},
74 	{
75 		.desc = "temperature",
76 		.type = ENVSYS_STEMP,
77 	}
78 };
79 
80 static struct si70xx_resolution si70xx_resolutions[] = {
81 	{
82 		.text = "12bit/14bit",
83 		.num = 0x00,
84 	},
85 	{
86 		.text = "8bit/12bit",
87 		.num = 0x01,
88 	},
89 	{
90 		.text = "10bit/13bit",
91 		.num = 0x80,
92 	},
93 	{
94 		.text = "11bit/11bit",
95 		.num = 0x81,
96 	}
97 };
98 
99 static const char si70xx_resolution_names[] =
100     "12bit/14bit, 8bit/12bit, 10bit/13bit, 11bit/11bit";
101 
102 static const int si70xx_heatervalues[] = {
103     0xdeadbeef, 0x00, 0x01, 0x02, 0x04, 0x08, 0x0f
104 };
105 
106 int
107 si70xx_verify_sysctl(SYSCTLFN_ARGS)
108 {
109 	int error, t;
110 	struct sysctlnode node;
111 
112 	node = *rnode;
113 	t = *(int *)rnode->sysctl_data;
114 	node.sysctl_data = &t;
115 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
116 	if (error || newp == NULL)
117 		return error;
118 
119 	if (t < 0)
120 		return EINVAL;
121 
122 	*(int *)rnode->sysctl_data = t;
123 
124 	return 0;
125 }
126 
127 int
128 si70xx_verify_sysctl_resolution(SYSCTLFN_ARGS)
129 {
130 	char buf[SI70XX_RES_NAME];
131 	struct si70xx_sc *sc;
132 	struct sysctlnode node;
133 	int error = 0;
134 	size_t i;
135 
136 	node = *rnode;
137 	sc = node.sysctl_data;
138 	(void) memcpy(buf, sc->sc_resolution, SI70XX_RES_NAME);
139 	node.sysctl_data = buf;
140 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
141 	if (error || newp == NULL)
142 		return error;
143 
144 	for (i = 0; i < __arraycount(si70xx_resolutions); i++) {
145 		if (memcmp(node.sysctl_data, si70xx_resolutions[i].text,
146 		    SI70XX_RES_NAME) == 0)
147 			break;
148 	}
149 
150 	if (i == __arraycount(si70xx_resolutions))
151 		return EINVAL;
152 	(void) memcpy(sc->sc_resolution, node.sysctl_data, SI70XX_RES_NAME);
153 
154 	error = si70xx_set_resolution(sc, i);
155 
156 	return error;
157 }
158 
159 int
160 si70xx_verify_sysctl_heateron(SYSCTLFN_ARGS)
161 {
162 	int 		error;
163 	bool 		t;
164 	struct si70xx_sc *sc;
165 	struct sysctlnode node;
166 
167 	node = *rnode;
168 	sc = node.sysctl_data;
169 	t = sc->sc_heateron;
170 	node.sysctl_data = &t;
171 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
172 	if (error || newp == NULL)
173 		return error;
174 
175 	sc->sc_heateron = t;
176 	error = si70xx_set_heateron(sc);
177 
178 	return error;
179 }
180 
181 int
182 si70xx_verify_sysctl_heatervalue(SYSCTLFN_ARGS)
183 {
184 	int 		error = 0, t;
185 	struct si70xx_sc *sc;
186 	struct sysctlnode node;
187 
188 	node = *rnode;
189 	sc = node.sysctl_data;
190 	t = sc->sc_heaterval;
191 	node.sysctl_data = &t;
192 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
193 	if (error || newp == NULL)
194 		return (error);
195 
196 	if (t < 1 || t >= __arraycount(si70xx_heatervalues))
197 		return (EINVAL);
198 
199 	sc->sc_heaterval = t;
200 	error = si70xx_set_heatervalue(sc, t);
201 
202 	return error;
203 }
204 
205 static uint8_t
206 si70xx_dir(uint8_t cmd, size_t len)
207 {
208 	switch (cmd) {
209 	case SI70XX_READ_USER_REG_1:
210 	case SI70XX_READ_HEATER_REG:
211 	case SI70XX_READ_ID_PT1A:
212 	case SI70XX_READ_ID_PT1B:
213 	case SI70XX_READ_ID_PT2A:
214 	case SI70XX_READ_ID_PT2B:
215 	case SI70XX_READ_FW_VERA:
216 	case SI70XX_READ_FW_VERB:
217 		return I2C_OP_READ_WITH_STOP;
218 	case SI70XX_WRITE_USER_REG_1:
219 	case SI70XX_WRITE_HEATER_REG:
220 	case SI70XX_RESET:
221 		return I2C_OP_WRITE_WITH_STOP;
222 	case SI70XX_MEASURE_RH_NOHOLD:
223 	case SI70XX_MEASURE_TEMP_NOHOLD:
224 		return len == 0 ? I2C_OP_READ : I2C_OP_READ_WITH_STOP;
225 	default:
226 		panic("%s: bad command %#x\n", __func__, cmd);
227 		return 0;
228 	}
229 }
230 
231 static int
232 si70xx_cmd(i2c_tag_t tag, i2c_addr_t addr, uint8_t *cmd,
233     uint8_t clen, uint8_t *buf, size_t blen)
234 {
235 	uint8_t dir;
236 	if (clen == 0)
237 		dir = blen == 0 ? I2C_OP_READ : I2C_OP_READ_WITH_STOP;
238 	else
239 		dir = si70xx_dir(cmd[0], blen);
240 
241 	if (dir == I2C_OP_READ || dir == I2C_OP_READ_WITH_STOP)
242 		memset(buf, 0, blen);
243 
244 	return iic_exec(tag, dir, addr, cmd, clen, buf, blen, 0);
245 }
246 
247 static int
248 si70xx_cmd0(struct si70xx_sc *sc, uint8_t *buf, size_t blen)
249 {
250 	return si70xx_cmd(sc->sc_tag, sc->sc_addr, NULL, 0, buf, blen);
251 }
252 
253 static int
254 si70xx_cmd1(struct si70xx_sc *sc, uint8_t cmd, uint8_t *buf, size_t blen)
255 {
256 	return si70xx_cmd(sc->sc_tag, sc->sc_addr, &cmd, 1, buf, blen);
257 }
258 
259 static int
260 si70xx_cmd2(struct si70xx_sc *sc, uint8_t cmd1, uint8_t cmd2, uint8_t *buf,
261     size_t blen)
262 {
263 	uint8_t cmd[] = { cmd1, cmd2 };
264 	return si70xx_cmd(sc->sc_tag, sc->sc_addr, cmd, __arraycount(cmd),
265 	    buf, blen);
266 }
267 
268 static int
269 si70xx_set_heateron(struct si70xx_sc * sc)
270 {
271 	int error;
272 	uint8_t userregister;
273 
274 	error = iic_acquire_bus(sc->sc_tag, 0);
275 	if (error) {
276 		DPRINTF(sc, 2, ("%s:%s: Failed to acquire bus: %d\n",
277 		    device_xname(sc->sc_dev), __func__, error));
278 		return error;
279 	}
280 
281 	error = si70xx_cmd1(sc, SI70XX_READ_USER_REG_1, &userregister, 1);
282 	if (error) {
283 		DPRINTF(sc, 2, ("%s: Failed to read user register 1: %d\n",
284 		    device_xname(sc->sc_dev), error));
285 		goto out;
286 	}
287 
288 	DPRINTF(sc, 2, ("%s:%s: reg 1 values before: %#x\n",
289 	    device_xname(sc->sc_dev), __func__, userregister));
290 	if (sc->sc_heateron) {
291 		userregister |= SI70XX_HTRE_MASK;
292 	} else {
293 		userregister &= ~SI70XX_HTRE_MASK;
294 	}
295 	DPRINTF(sc, 2, ("%s:%s: user reg 1 values after: %#x\n",
296 	    device_xname(sc->sc_dev), __func__, userregister));
297 
298 	error = si70xx_cmd1(sc, SI70XX_WRITE_USER_REG_1, &userregister, 1);
299 	if (error) {
300 		DPRINTF(sc, 2, ("%s: Failed to write user register 1: %d\n",
301 		    device_xname(sc->sc_dev), error));
302 	}
303 out:
304 	iic_release_bus(sc->sc_tag, 0);
305 	return error;
306 }
307 
308 static int
309 si70xx_set_resolution(struct si70xx_sc * sc, size_t index)
310 {
311 	int error;
312 	uint8_t userregister;
313 
314 	error = iic_acquire_bus(sc->sc_tag, 0);
315 	if (error) {
316 		DPRINTF(sc, 2, ("%s: Failed to acquire bus: %d\n",
317 		    device_xname(sc->sc_dev), error));
318 		return error;
319 	}
320 
321 	error = si70xx_cmd1(sc, SI70XX_READ_USER_REG_1, &userregister, 1);
322 	if (error) {
323 		DPRINTF(sc, 2, ("%s: Failed to read user register 1: %d\n",
324 		    device_xname(sc->sc_dev), error));
325 		goto out;
326 	}
327 
328 	DPRINTF(sc, 2, ("%s:%s: reg 1 values before: %#x\n",
329 	    device_xname(sc->sc_dev), __func__, userregister));
330 	userregister &= (~SI70XX_RESOLUTION_MASK);
331 	userregister |= si70xx_resolutions[index].num;
332 	DPRINTF(sc, 2, ("%s:%s: reg 1 values after: %#x\n",
333 	    device_xname(sc->sc_dev), __func__, userregister));
334 
335 	error = si70xx_cmd1(sc, SI70XX_WRITE_USER_REG_1, &userregister, 1);
336 	if (error) {
337 		DPRINTF(sc, 2, ("%s: Failed to write user register 1: %d\n",
338 		    device_xname(sc->sc_dev), error));
339 	}
340 out:
341 	iic_release_bus(sc->sc_tag, 0);
342 	return error;
343 }
344 
345 static int
346 si70xx_set_heatervalue(struct si70xx_sc * sc, size_t index)
347 {
348 	int error;
349 	uint8_t heaterregister;
350 
351 	error = iic_acquire_bus(sc->sc_tag, 0);
352 	if (error) {
353 		DPRINTF(sc, 2, ("%s: Failed to acquire bus: %d\n",
354 		    device_xname(sc->sc_dev), error));
355 		return error;
356 	}
357 	error = si70xx_cmd1(sc, SI70XX_READ_HEATER_REG, &heaterregister, 1);
358 	if (error) {
359 		DPRINTF(sc, 2, ("%s: Failed to read heater register: %d\n",
360 		    device_xname(sc->sc_dev), error));
361 		goto out;
362 	}
363 
364 	DPRINTF(sc, 2, ("%s:%s: heater values before: %#x\n",
365 	    device_xname(sc->sc_dev), __func__, heaterregister));
366 	heaterregister &= ~SI70XX_HEATER_MASK;
367 	heaterregister |= si70xx_heatervalues[index];
368 	DPRINTF(sc, 2, ("%s:%s: heater values after: %#x\n",
369 	    device_xname(sc->sc_dev), __func__, heaterregister));
370 
371 	error = si70xx_cmd1(sc, SI70XX_WRITE_HEATER_REG, &heaterregister, 1);
372 	if (error) {
373 		DPRINTF(sc, 2, ("%s: Failed to write heater register: %d\n",
374 		    device_xname(sc->sc_dev), error));
375 	}
376 out:
377 	iic_release_bus(sc->sc_tag, 0);
378 	return error;
379 }
380 
381 static int
382 si70xx_update_heater(struct si70xx_sc *sc)
383 {
384 	size_t i;
385 	int error;
386 	uint8_t heaterregister;
387 
388 	error = si70xx_cmd1(sc, SI70XX_READ_HEATER_REG, &heaterregister, 1);
389 	if (error) {
390 		DPRINTF(sc, 2, ("%s: Failed to read heater register: %d\n",
391 		    device_xname(sc->sc_dev), error));
392 		return error;
393 	}
394 
395 	DPRINTF(sc, 2, ("%s: read heater reg values: %02x\n",
396 	    device_xname(sc->sc_dev), heaterregister));
397 
398 	uint8_t heat = heaterregister & SI70XX_HEATER_MASK;
399 	for (i = 0; i < __arraycount(si70xx_heatervalues); i++) {
400 		if (si70xx_heatervalues[i] == heat)
401 			break;
402 	}
403 	sc->sc_heaterval = i != __arraycount(si70xx_heatervalues) ? i : 0;
404 	return 0;
405 }
406 
407 static int
408 si70xx_update_user(struct si70xx_sc *sc)
409 {
410 	size_t i;
411 	int error;
412 	uint8_t userregister;
413 
414 	error = si70xx_cmd1(sc, SI70XX_READ_USER_REG_1, &userregister, 1);
415 	if (error) {
416 		DPRINTF(sc, 2, ("%s: Failed to read user register 1: %d\n",
417 		    device_xname(sc->sc_dev), error));
418 		return error;
419 	}
420 	DPRINTF(sc, 2, ("%s: read user reg 1 values: %#x\n",
421 	    device_xname(sc->sc_dev), userregister));
422 
423 	uint8_t res = userregister & SI70XX_RESOLUTION_MASK;
424 	for (i = 0; i < __arraycount(si70xx_resolutions); i++) {
425 		if (si70xx_resolutions[i].num == res)
426 			break;
427 	}
428 
429 	if (i != __arraycount(si70xx_resolutions)) {
430 		memcpy(sc->sc_resolution, si70xx_resolutions[i].text,
431 		    SI70XX_RES_NAME);
432 	} else {
433 		snprintf(sc->sc_resolution, SI70XX_RES_NAME, "%02x", res);
434 	}
435 
436 	sc->sc_vddok = (userregister & SI70XX_VDDS_MASK) == 0;
437 	sc->sc_heaterval = userregister & SI70XX_HTRE_MASK;
438 	return 0;
439 }
440 
441 static int
442 si70xx_update_status(struct si70xx_sc *sc)
443 {
444 	int error1 = si70xx_update_user(sc);
445 	int error2 = si70xx_update_heater(sc);
446 	return error1 ? error1 : error2;
447 }
448 
449 static	uint8_t
450 si70xx_crc(uint8_t * data, size_t size)
451 {
452 	uint8_t crc = 0;
453 
454 	for (size_t i = 0; i < size; i++) {
455 		crc ^= data[i];
456 		for (size_t j = 8; j > 0; j--) {
457 			if (crc & 0x80)
458 				crc = (crc << 1) ^ 0x131;
459 			else
460 				crc <<= 1;
461 		}
462 	}
463 	return crc;
464 }
465 
466 static int
467 si70xx_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug)
468 {
469 	uint8_t reg = SI70XX_READ_USER_REG_1;
470 	uint8_t buf;
471 	int error;
472 
473 	error = si70xx_cmd(tag, addr, &reg, 1, &buf, 1);
474 	if (matchdebug) {
475 		printf("poke X 1: %d\n", error);
476 	}
477 	return error;
478 }
479 
480 static int
481 si70xx_sysctl_init(struct si70xx_sc *sc)
482 {
483 	int error;
484 	const struct sysctlnode *cnode;
485 	int sysctlroot_num;
486 
487 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
488 	    0, CTLTYPE_NODE, device_xname(sc->sc_dev),
489 	    SYSCTL_DESCR("si70xx controls"), NULL, 0, NULL, 0, CTL_HW,
490 	    CTL_CREATE, CTL_EOL)) != 0)
491 		return error;
492 
493 	sysctlroot_num = cnode->sysctl_num;
494 
495 #ifdef SI70XX_DEBUG
496 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
497 	    CTLFLAG_READWRITE, CTLTYPE_INT, "debug",
498 	    SYSCTL_DESCR("Debug level"), si70xx_verify_sysctl, 0,
499 	    &sc->sc_si70xxdebug, 0, CTL_HW, sysctlroot_num, CTL_CREATE,
500 	    CTL_EOL)) != 0)
501 		return error;
502 
503 #endif
504 
505 #ifdef HAVE_I2C_EXECV
506 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
507 	    CTLFLAG_READWRITE, CTLTYPE_INT, "clockstretch",
508 	    SYSCTL_DESCR("Clockstretch value"), si70xx_verify_sysctl, 0,
509 	    &sc->sc_clockstretch, 0, CTL_HW, sysctlroot_num, CTL_CREATE,
510 	    CTL_EOL)) != 0)
511 		return error;
512 #endif
513 
514 
515 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
516 	    CTLFLAG_READWRITE, CTLTYPE_INT, "readattempts",
517 	    SYSCTL_DESCR("The number of times to attempt to read the values"),
518 	    si70xx_verify_sysctl, 0, &sc->sc_readattempts, 0, CTL_HW,
519 	    sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
520 		return error;
521 
522 
523 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
524 	    CTLFLAG_READONLY, CTLTYPE_STRING, "resolutions",
525 	    SYSCTL_DESCR("Valid resolutions"), 0, 0,
526 	    __UNCONST(si70xx_resolution_names),
527 	    sizeof(si70xx_resolution_names) + 1,
528 	    CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
529 		return error;
530 
531 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
532 	    CTLFLAG_READWRITE, CTLTYPE_STRING, "resolution",
533 	    SYSCTL_DESCR("Resolution of RH and Temp"),
534 	    si70xx_verify_sysctl_resolution, 0, (void *) sc,
535 	    SI70XX_RES_NAME, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
536 		return error;
537 
538 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
539 	    CTLFLAG_READWRITE, CTLTYPE_BOOL, "ignorecrc",
540 	    SYSCTL_DESCR("Ignore the CRC byte"), NULL, 0, &sc->sc_ignorecrc,
541 	    0, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
542 		return error;
543 
544 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
545 	    CTLFLAG_READONLY, CTLTYPE_BOOL, "vddok",
546 	    SYSCTL_DESCR("Vdd at least 1.9v"), NULL, 0, &sc->sc_vddok, 0,
547 	    CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
548 		return error;
549 
550 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
551 	    CTLFLAG_READWRITE, CTLTYPE_BOOL, "heateron",
552 	    SYSCTL_DESCR("Heater on"), si70xx_verify_sysctl_heateron, 0,
553 	    (void *)sc, 0, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
554 		return error;
555 
556 	return sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
557 	    CTLFLAG_READWRITE, CTLTYPE_INT, "heaterstrength",
558 	    SYSCTL_DESCR("Heater strength 1 to 6"),
559 	    si70xx_verify_sysctl_heatervalue, 0, (void *)sc, 0, CTL_HW,
560 	    sysctlroot_num, CTL_CREATE, CTL_EOL);
561 }
562 
563 static int
564 si70xx_match(device_t parent, cfdata_t match, void *aux)
565 {
566 	struct i2c_attach_args *ia = aux;
567 	int error, match_result;
568 	const bool matchdebug = false;
569 
570 	if (iic_use_direct_match(ia, match, NULL, &match_result))
571 		return match_result;
572 
573 	/* indirect config - check for configured address */
574 	if (ia->ia_addr != SI70XX_TYPICAL_ADDR)
575 		return 0;
576 
577 	/*
578 	 * Check to see if something is really at this i2c address. This will
579 	 * keep phantom devices from appearing
580 	 */
581 	if (iic_acquire_bus(ia->ia_tag, 0) != 0) {
582 		if (matchdebug)
583 			printf("in match acquire bus failed\n");
584 		return 0;
585 	}
586 
587 	error = si70xx_poke(ia->ia_tag, ia->ia_addr, matchdebug);
588 	iic_release_bus(ia->ia_tag, 0);
589 
590 	return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0;
591 }
592 
593 static void
594 si70xx_attach(device_t parent, device_t self, void *aux)
595 {
596 	struct si70xx_sc *sc;
597 	struct i2c_attach_args *ia;
598 	int error, i;
599 	int ecount = 0;
600 	uint8_t buf[8];
601 	uint8_t testcrcpt1[4];
602 	uint8_t testcrcpt2[4];
603 	uint8_t crc1 = 0, crc2 = 0;
604 	uint8_t readcrc1 = 0, readcrc2 = 0;
605 	uint8_t fwversion, model;
606 
607 	ia = aux;
608 	sc = device_private(self);
609 
610 	sc->sc_dev = self;
611 	sc->sc_tag = ia->ia_tag;
612 	sc->sc_addr = ia->ia_addr;
613 	sc->sc_si70xxdebug = 0;
614 #ifdef HAVE_I2C_EXECV
615 	sc->sc_clockstretch = 2048;
616 #endif
617 	sc->sc_readattempts = 25;
618 	sc->sc_ignorecrc = false;
619 	sc->sc_sme = NULL;
620 
621 	aprint_normal("\n");
622 
623 	mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);
624 	sc->sc_numsensors = __arraycount(si70xx_sensors);
625 
626 	if ((sc->sc_sme = sysmon_envsys_create()) == NULL) {
627 		aprint_error_dev(self,
628 		    "Unable to create sysmon structure\n");
629 		sc->sc_sme = NULL;
630 		return;
631 	}
632 	if ((error = si70xx_sysctl_init(sc)) != 0) {
633 		aprint_error_dev(self, "Can't setup sysctl tree (%d)\n", error);
634 		goto out;
635 	}
636 
637 	error = iic_acquire_bus(sc->sc_tag, 0);
638 	if (error) {
639 		aprint_error_dev(self, "Could not acquire iic bus: %d\n",
640 		    error);
641 		goto out;
642 	}
643 	error = si70xx_cmd1(sc, SI70XX_RESET, NULL, 0);
644 	if (error != 0)
645 		aprint_error_dev(self, "Reset failed: %d\n", error);
646 
647 	delay(15000);	/* 15 ms max */
648 
649 	error = si70xx_cmd2(sc, SI70XX_READ_ID_PT1A, SI70XX_READ_ID_PT1B,
650 	    buf, 8);
651 	if (error) {
652 		aprint_error_dev(self, "Failed to read first part of ID: %d\n",
653 		    error);
654 		ecount++;
655 	}
656 	testcrcpt1[0] = buf[0];
657 	testcrcpt1[1] = buf[2];
658 	testcrcpt1[2] = buf[4];
659 	testcrcpt1[3] = buf[6];
660 	readcrc1 = buf[7];
661 	crc1 = si70xx_crc(testcrcpt1, 4);
662 
663 	DPRINTF(sc, 2, ("%s: read 1 values: %02x%02x%02x%02x%02x%02x%02x%02x "
664 	    "- %02x\n", device_xname(sc->sc_dev), buf[0], buf[1],
665 	    buf[2], buf[3], buf[4], buf[5], buf[6], buf[7],
666 	    crc1));
667 
668 	error = si70xx_cmd2(sc, SI70XX_READ_ID_PT2A, SI70XX_READ_ID_PT2B,
669 	    buf, 8);
670 	if (error != 0) {
671 		aprint_error_dev(self, "Failed to read second part of ID: %d\n",
672 		    error);
673 		ecount++;
674 	}
675 	model = testcrcpt2[0] = buf[0];
676 	testcrcpt2[1] = buf[1];
677 	testcrcpt2[2] = buf[3];
678 	testcrcpt2[3] = buf[4];
679 	readcrc2 = buf[5];
680 	crc2 = si70xx_crc(testcrcpt2, 4);
681 
682 	DPRINTF(sc, 2, ("%s: read 2 values: %02x%02x%02x%02x%02x%02x - %02x\n",
683 	    device_xname(sc->sc_dev), buf[0], buf[1], buf[2],
684 	    buf[3], buf[4], buf[5], crc2));
685 
686 	error = si70xx_cmd2(sc, SI70XX_READ_FW_VERA, SI70XX_READ_FW_VERB,
687 	    buf, 8);
688 
689 	if (error) {
690 		aprint_error_dev(self, "Failed to read firware version: %d\n",
691 		    error);
692 		ecount++;
693 	}
694 	fwversion = buf[0];
695 	DPRINTF(sc, 2, ("%s: read fw values: %#x\n", device_xname(sc->sc_dev),
696 	    fwversion));
697 
698 	error = si70xx_update_status(sc);
699 	iic_release_bus(sc->sc_tag, 0);
700 	if (error != 0) {
701 		aprint_error_dev(self, "Failed to update status: %x\n", error);
702 		aprint_error_dev(self, "Unable to setup device\n");
703 		goto out;
704 	}
705 
706 	for (i = 0; i < sc->sc_numsensors; i++) {
707 		strlcpy(sc->sc_sensors[i].desc, si70xx_sensors[i].desc,
708 		    sizeof(sc->sc_sensors[i].desc));
709 
710 		sc->sc_sensors[i].units = si70xx_sensors[i].type;
711 		sc->sc_sensors[i].state = ENVSYS_SINVALID;
712 
713 		DPRINTF(sc, 2, ("%s: registering sensor %d (%s)\n", __func__, i,
714 		    sc->sc_sensors[i].desc));
715 
716 		error = sysmon_envsys_sensor_attach(sc->sc_sme,
717 		    &sc->sc_sensors[i]);
718 		if (error) {
719 			aprint_error_dev(self,
720 			    "Unable to attach sensor %d: %d\n", i, error);
721 			sc->sc_sme = NULL;
722 			goto out;
723 		}
724 	}
725 
726 	sc->sc_sme->sme_name = device_xname(sc->sc_dev);
727 	sc->sc_sme->sme_cookie = sc;
728 	sc->sc_sme->sme_refresh = si70xx_refresh;
729 
730 	DPRINTF(sc, 2, ("si70xx_attach: registering with envsys\n"));
731 
732 	if (sysmon_envsys_register(sc->sc_sme)) {
733 		aprint_error_dev(self,
734 			"unable to register with sysmon\n");
735 		sysmon_envsys_destroy(sc->sc_sme);
736 		sc->sc_sme = NULL;
737 		return;
738 	}
739 	if (ecount != 0) {
740 		aprint_normal_dev(self, "Could not read model, "
741 		    "probably an HTU21D\n");
742 		return;
743 	}
744 
745 	char modelstr[64];
746 	switch (model) {
747 	case 0:
748 	case 0xff:
749 		snprintf(modelstr, sizeof(modelstr), "Engineering Sample");
750 		break;
751 	case 13:
752 	case 20:
753 	case 21:
754 		snprintf(modelstr, sizeof(modelstr), "SI70%d", model);
755 		break;
756 	default:
757 		snprintf(modelstr, sizeof(modelstr), "Unknown SI70%d", model);
758 		break;
759 	}
760 
761 	const char *fwversionstr;
762 	switch (fwversion) {
763 	case 0xff:
764 		fwversionstr = "1.0";
765 		break;
766 	case 0x20:
767 		fwversionstr = "2.0";
768 		break;
769 	default:
770 		fwversionstr = "unknown";
771 		break;
772 	}
773 
774 	aprint_normal_dev(self, "Silicon Labs Model: %s, "
775 	    "Firmware version: %s, "
776 	    "Serial number: %02x%02x%02x%02x%02x%02x%02x%02x%s",
777 	    modelstr, fwversionstr, testcrcpt1[0], testcrcpt1[1],
778 	    testcrcpt1[2], testcrcpt1[3], testcrcpt2[0], testcrcpt2[1],
779 	    testcrcpt2[2], testcrcpt2[3],
780 	    (crc1 == readcrc1 && crc2 == readcrc2) ? "\n" : " (bad crc)\n");
781 	return;
782 out:
783 	sysmon_envsys_destroy(sc->sc_sme);
784 	sc->sc_sme = NULL;
785 }
786 
787 static int
788 si70xx_exec(struct si70xx_sc *sc, uint8_t cmd, envsys_data_t *edata)
789 {
790 	int error;
791 	int xdelay;
792 	const char *name;
793 	int64_t mul, offs;
794 	uint8_t buf[3];
795 
796 	switch (cmd) {
797 	case SI70XX_MEASURE_RH_NOHOLD:
798 		/*
799 		 * The published conversion for RH is: %RH =
800 		 * ((125 * RHCODE) / 65536) - 6
801 		 *
802 		 * The sysmon infrastructure for RH wants %RH *
803 		 * 10^6 The result will fit in 32 bits, but
804 		 * the intermediate values will not.
805 		 */
806 		mul = 125000000;
807 		offs = -6000000;
808 		/*
809 		 * Conversion times for %RH in ms
810 		 *
811 		 *        	Typical Max
812 		 * 12-bit	10.0	12.0
813 		 * 11-bit	 5.8	 7.0
814 		 * 10-bit	 3.7	 4.5
815 		 *  8-bit	 2.6	 3.1
816 		 *
817 		 * A call to read %RH will also read temperature.  The
818 		 * conversion time will be the amount of time above
819 		 * plus the amount of time for temperature below
820 		 */
821 		xdelay = 10500;
822 		name = "RH";
823 		break;
824 	case SI70XX_MEASURE_TEMP_NOHOLD:
825 		/*
826 		 * The published conversion for temp is:
827 		 * degree C = ((175.72 * TEMPCODE) / 65536) -
828 		 * 46.85
829 		 *
830 		 * The sysmon infrastructure for temp wants
831 		 * microkelvin.  This is simple, as degree C
832 		 * converts directly with K with simple
833 		 * addition. The result will fit in 32 bits,
834 		 * but the intermediate values will not.
835 		 */
836 		mul = 175720000;
837 		offs = 226300000;
838 		/*
839 		 * Conversion times for temperature in ms
840 	 	 *
841 		 *		Typical	Max
842 		 * 14-bit	7.0	10.8
843 		 * 13-bit	4.0	 6.2
844 		 * 12-bit	2.4	 3.8
845 		 * 11-bit	1.5	 2.4
846 		 */
847 		xdelay = 4750;
848 		name = "TEMP";
849 		break;
850 	default:
851 		return EINVAL;
852 	}
853 
854 #if HAVE_I2C_EXECV
855 	memset(buf, 0, sizeof(buf));
856 	error = iic_execv(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
857 	    &cmd, 1, buf, sizeof(buf), 0, I2C_ATTR_CLOCKSTRETCH,
858 	    sc->sc_clockstretch, I2C_ATTR_EOL);
859 #else
860 	/*
861 	 * The lower level driver must support the ability to
862 	 * do a zero length read, otherwise this breaks
863 	 */
864 	error = si70xx_cmd1(sc, cmd, buf, 0);
865 	if (error) {
866 		DPRINTF(sc, 2, ("%s: Failed to read NO HOLD %s %d %d\n",
867 		    device_xname(sc->sc_dev), name, 1, error));
868 		return error;
869 	}
870 
871 	/*
872 	 * It will probably be at least this long... we would
873 	 * not have to do this sort of thing if clock
874 	 * stretching worked.  Even this is a problem for the
875 	 * RPI without a patch to remove a [apparently] not
876 	 * needed KASSERT()
877 	 */
878 	delay(xdelay);
879 
880 	for (int aint = 0; aint < sc->sc_readattempts; aint++) {
881 		error = si70xx_cmd0(sc, buf, sizeof(buf));
882 		if (error == 0)
883 			break;
884 		DPRINTF(sc, 2, ("%s: Failed to read NO HOLD RH"
885 		    " %d %d\n", device_xname(sc->sc_dev), 2, error));
886 		delay(1000);
887 	}
888 #endif
889 
890 	DPRINTF(sc, 2, ("%s: %s values: %02x%02x%02x - %02x\n",
891 	    device_xname(sc->sc_dev), name, buf[0], buf[1], buf[2],
892 	    si70xx_crc(buf, 2)));
893 
894 	uint8_t crc;
895 	if (sc->sc_ignorecrc) {
896 		crc = buf[2];
897 	} else {
898 		crc = si70xx_crc(buf, 2);
899 	}
900 
901 	if (crc != buf[2]) {
902 		DPRINTF(sc, 2, ("%s: Bad CRC for %s: %#x and %#x\n",
903 		    device_xname(sc->sc_dev), name, crc, buf[2]));
904 		return EINVAL;
905 	}
906 
907 	uint16_t val16 = (buf[0] << 8) | buf[1];
908 	uint64_t val64 = ((mul * val16) >> 16) + offs;
909 	DPRINTF(sc, 2, ("%s: %s calculated values: %x %#jx\n",
910 	    device_xname(sc->sc_dev), name, val16, (uintmax_t)val64));
911 	edata->value_cur = (uint32_t) val64;
912 	edata->state = ENVSYS_SVALID;
913 	return 0;
914 }
915 
916 static void
917 si70xx_refresh(struct sysmon_envsys * sme, envsys_data_t * edata)
918 {
919 	struct si70xx_sc *sc;
920 	int 		error;
921 
922 	sc = sme->sme_cookie;
923 	edata->state = ENVSYS_SINVALID;
924 
925 	mutex_enter(&sc->sc_mutex);
926 	error = iic_acquire_bus(sc->sc_tag, 0);
927 	if (error) {
928 		DPRINTF(sc, 2, ("%s: Could not acquire i2c bus: %x\n",
929 		    device_xname(sc->sc_dev), error));
930 		goto out;
931 	}
932 	error = si70xx_update_status(sc);
933 	if (error) {
934 		DPRINTF(sc, 2, ("%s: Failed to update status in refresh %d\n",
935 		    device_xname(sc->sc_dev), error));
936 		goto out1;
937 	}
938 	switch (edata->sensor) {
939 	case SI70XX_HUMIDITY_SENSOR:
940 		error = si70xx_exec(sc, SI70XX_MEASURE_RH_NOHOLD, edata);
941 		break;
942 
943 	case SI70XX_TEMP_SENSOR:
944 		error = si70xx_exec(sc, SI70XX_MEASURE_TEMP_NOHOLD, edata);
945 		break;
946 	default:
947 		error = EINVAL;
948 		break;
949 	}
950 
951 	if (error) {
952 		DPRINTF(sc, 2, ("%s: Failed to get new status in refresh %d\n",
953 		    device_xname(sc->sc_dev), error));
954 	}
955 out1:
956 	iic_release_bus(sc->sc_tag, 0);
957 out:
958 	mutex_exit(&sc->sc_mutex);
959 }
960 
961 static int
962 si70xx_detach(device_t self, int flags)
963 {
964 	struct si70xx_sc *sc;
965 
966 	sc = device_private(self);
967 
968 	mutex_enter(&sc->sc_mutex);
969 
970 	/* Remove the sensors */
971 	if (sc->sc_sme != NULL) {
972 		sysmon_envsys_unregister(sc->sc_sme);
973 		sc->sc_sme = NULL;
974 	}
975 	mutex_exit(&sc->sc_mutex);
976 
977 	/* Remove the sysctl tree */
978 	sysctl_teardown(&sc->sc_si70xxlog);
979 
980 	/* Remove the mutex */
981 	mutex_destroy(&sc->sc_mutex);
982 
983 	return 0;
984 }
985 
986 MODULE(MODULE_CLASS_DRIVER, si70xxtemp, "i2cexec,sysmon_envsys");
987 
988 #ifdef _MODULE
989 #include "ioconf.c"
990 #endif
991 
992 static int
993 si70xxtemp_modcmd(modcmd_t cmd, void *opaque)
994 {
995 
996 	switch (cmd) {
997 	case MODULE_CMD_INIT:
998 #ifdef _MODULE
999 		return config_init_component(cfdriver_ioconf_si70xxtemp,
1000 		    cfattach_ioconf_si70xxtemp, cfdata_ioconf_si70xxtemp);
1001 #else
1002 		return 0;
1003 #endif
1004 	case MODULE_CMD_FINI:
1005 #ifdef _MODULE
1006 		return config_fini_component(cfdriver_ioconf_si70xxtemp,
1007 		      cfattach_ioconf_si70xxtemp, cfdata_ioconf_si70xxtemp);
1008 #else
1009 		return 0;
1010 #endif
1011 	default:
1012 		return ENOTTY;
1013 	}
1014 }
1015