xref: /netbsd-src/sys/dev/i2c/si70xx.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /*	$NetBSD: si70xx.c,v 1.11 2022/03/30 00:06:50 pgoyette 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 1.11 2022/03/30 00:06:50 pgoyette Exp $");
21 
22 /*
23   Driver for the Silicon Labs SI7013/SI7020/SI7021, HTU21D and SHT21
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 = 0;
446 	if (! sc->sc_noheater) {
447 		error2 = si70xx_update_heater(sc);
448 	}
449 	return error1 ? error1 : error2;
450 }
451 
452 static	uint8_t
453 si70xx_crc(uint8_t * data, size_t size)
454 {
455 	uint8_t crc = 0;
456 
457 	for (size_t i = 0; i < size; i++) {
458 		crc ^= data[i];
459 		for (size_t j = 8; j > 0; j--) {
460 			if (crc & 0x80)
461 				crc = (crc << 1) ^ 0x131;
462 			else
463 				crc <<= 1;
464 		}
465 	}
466 	return crc;
467 }
468 
469 static int
470 si70xx_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug)
471 {
472 	uint8_t reg = SI70XX_READ_USER_REG_1;
473 	uint8_t buf;
474 	int error;
475 
476 	error = si70xx_cmd(tag, addr, &reg, 1, &buf, 1);
477 	if (matchdebug) {
478 		printf("poke X 1: %d\n", error);
479 	}
480 	return error;
481 }
482 
483 static int
484 si70xx_sysctl_init(struct si70xx_sc *sc)
485 {
486 	int error;
487 	const struct sysctlnode *cnode;
488 	int sysctlroot_num;
489 
490 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
491 	    0, CTLTYPE_NODE, device_xname(sc->sc_dev),
492 	    SYSCTL_DESCR("si70xx controls"), NULL, 0, NULL, 0, CTL_HW,
493 	    CTL_CREATE, CTL_EOL)) != 0)
494 		return error;
495 
496 	sysctlroot_num = cnode->sysctl_num;
497 
498 #ifdef SI70XX_DEBUG
499 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
500 	    CTLFLAG_READWRITE, CTLTYPE_INT, "debug",
501 	    SYSCTL_DESCR("Debug level"), si70xx_verify_sysctl, 0,
502 	    &sc->sc_si70xxdebug, 0, CTL_HW, sysctlroot_num, CTL_CREATE,
503 	    CTL_EOL)) != 0)
504 		return error;
505 
506 #endif
507 
508 #ifdef HAVE_I2C_EXECV
509 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
510 	    CTLFLAG_READWRITE, CTLTYPE_INT, "clockstretch",
511 	    SYSCTL_DESCR("Clockstretch value"), si70xx_verify_sysctl, 0,
512 	    &sc->sc_clockstretch, 0, CTL_HW, sysctlroot_num, CTL_CREATE,
513 	    CTL_EOL)) != 0)
514 		return error;
515 #endif
516 
517 
518 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
519 	    CTLFLAG_READWRITE, CTLTYPE_INT, "readattempts",
520 	    SYSCTL_DESCR("The number of times to attempt to read the values"),
521 	    si70xx_verify_sysctl, 0, &sc->sc_readattempts, 0, CTL_HW,
522 	    sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
523 		return error;
524 
525 
526 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
527 	    CTLFLAG_READONLY, CTLTYPE_STRING, "resolutions",
528 	    SYSCTL_DESCR("Valid resolutions"), 0, 0,
529 	    __UNCONST(si70xx_resolution_names),
530 	    sizeof(si70xx_resolution_names) + 1,
531 	    CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
532 		return error;
533 
534 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
535 	    CTLFLAG_READWRITE, CTLTYPE_STRING, "resolution",
536 	    SYSCTL_DESCR("Resolution of RH and Temp"),
537 	    si70xx_verify_sysctl_resolution, 0, (void *) sc,
538 	    SI70XX_RES_NAME, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
539 		return error;
540 
541 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
542 	    CTLFLAG_READWRITE, CTLTYPE_BOOL, "ignorecrc",
543 	    SYSCTL_DESCR("Ignore the CRC byte"), NULL, 0, &sc->sc_ignorecrc,
544 	    0, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
545 		return error;
546 
547 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
548 	    CTLFLAG_READONLY, CTLTYPE_BOOL, "vddok",
549 	    SYSCTL_DESCR("Vdd at least 1.9v"), NULL, 0, &sc->sc_vddok, 0,
550 	    CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
551 		return error;
552 
553 	if (! sc->sc_noheater) {
554 		if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
555 		    CTLFLAG_READWRITE, CTLTYPE_BOOL, "heateron",
556 		    SYSCTL_DESCR("Heater on"), si70xx_verify_sysctl_heateron, 0,
557 		    (void *)sc, 0, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
558 			return error;
559 
560 		if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
561 		    CTLFLAG_READWRITE, CTLTYPE_INT, "heaterstrength",
562 		    SYSCTL_DESCR("Heater strength 1 to 6"),
563 		    si70xx_verify_sysctl_heatervalue, 0, (void *)sc, 0, CTL_HW,
564 		    sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
565 			return error;
566 	}
567 
568 	return 0;
569 }
570 
571 static int
572 si70xx_match(device_t parent, cfdata_t match, void *aux)
573 {
574 	struct i2c_attach_args *ia = aux;
575 	int error, match_result;
576 	const bool matchdebug = false;
577 
578 	if (iic_use_direct_match(ia, match, NULL, &match_result))
579 		return match_result;
580 
581 	/* indirect config - check for configured address */
582 	if (ia->ia_addr != SI70XX_TYPICAL_ADDR)
583 		return 0;
584 
585 	/*
586 	 * Check to see if something is really at this i2c address. This will
587 	 * keep phantom devices from appearing
588 	 */
589 	if (iic_acquire_bus(ia->ia_tag, 0) != 0) {
590 		if (matchdebug)
591 			printf("in match acquire bus failed\n");
592 		return 0;
593 	}
594 
595 	error = si70xx_poke(ia->ia_tag, ia->ia_addr, matchdebug);
596 	iic_release_bus(ia->ia_tag, 0);
597 
598 	return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0;
599 }
600 
601 static void
602 si70xx_attach(device_t parent, device_t self, void *aux)
603 {
604 	struct si70xx_sc *sc;
605 	struct i2c_attach_args *ia;
606 	int error, i;
607 	int ecount = 0;
608 	uint8_t buf[8];
609 	uint8_t testcrcpt1[4];
610 	uint8_t testcrcpt2[4];
611 	uint8_t crc1 = 0, crc2 = 0;
612 	bool validcrcpt1, validcrcpt2;
613 	uint8_t readcrc1 = 0, readcrc2 = 0;
614 	uint8_t fwversion = 0, model, heaterregister;
615 
616 	ia = aux;
617 	sc = device_private(self);
618 
619 	sc->sc_dev = self;
620 	sc->sc_tag = ia->ia_tag;
621 	sc->sc_addr = ia->ia_addr;
622 	sc->sc_si70xxdebug = 0;
623 #ifdef HAVE_I2C_EXECV
624 	sc->sc_clockstretch = 2048;
625 #endif
626 	sc->sc_readattempts = 40;
627 	sc->sc_ignorecrc = false;
628 	sc->sc_sme = NULL;
629 	sc->sc_noheater = false;
630 	sc->sc_nofw = false;
631 
632 	aprint_normal("\n");
633 
634 	mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);
635 	sc->sc_numsensors = __arraycount(si70xx_sensors);
636 
637 	if ((sc->sc_sme = sysmon_envsys_create()) == NULL) {
638 		aprint_error_dev(self,
639 		    "Unable to create sysmon structure\n");
640 		sc->sc_sme = NULL;
641 		return;
642 	}
643 
644 	error = iic_acquire_bus(sc->sc_tag, 0);
645 	if (error) {
646 		aprint_error_dev(self, "Could not acquire iic bus: %d\n",
647 		    error);
648 		goto out;
649 	}
650 	error = si70xx_cmd1(sc, SI70XX_RESET, NULL, 0);
651 	if (error != 0)
652 		aprint_error_dev(self, "Reset failed: %d\n", error);
653 
654 	delay(15000);	/* 15 ms max */
655 
656 	error = si70xx_cmd2(sc, SI70XX_READ_ID_PT1A, SI70XX_READ_ID_PT1B,
657 	    buf, 8);
658 	if (error) {
659 		aprint_error_dev(self, "Failed to read first part of ID: %d\n",
660 		    error);
661 		ecount++;
662 	}
663 	testcrcpt1[0] = buf[0];
664 	testcrcpt1[1] = buf[2];
665 	testcrcpt1[2] = buf[4];
666 	testcrcpt1[3] = buf[6];
667 	readcrc1 = buf[7];
668 	crc1 = si70xx_crc(testcrcpt1, 4);
669 	/* A "real" SI70xx has the CRC cover the entire first part of the
670 	 * serial number.  An HTU21D has the CRC broken out into each
671 	 * part of the serial number.
672 	 */
673 	validcrcpt1 = (readcrc1 == crc1);
674 	if (! validcrcpt1) {
675 		validcrcpt1 = (si70xx_crc(&testcrcpt1[0],1) == buf[1] &&
676 		    si70xx_crc(&testcrcpt1[1],1) == buf[3] &&
677 		    si70xx_crc(&testcrcpt1[2],1) == buf[5] &&
678 		    si70xx_crc(&testcrcpt1[3],1) == buf[7]);
679 		DPRINTF(sc, 2, ("%s: Part 1 SN CRC was not valid for real type, "
680 		    "check clone: %d\n", device_xname(sc->sc_dev), validcrcpt1));
681 	}
682 
683 	DPRINTF(sc, 2, ("%s: read 1 values: %02x%02x%02x%02x%02x%02x%02x%02x "
684 	    "- %02x -- %d\n", device_xname(sc->sc_dev), buf[0], buf[1],
685 	    buf[2], buf[3], buf[4], buf[5], buf[6], buf[7],
686 	    crc1, validcrcpt1));
687 
688 	error = si70xx_cmd2(sc, SI70XX_READ_ID_PT2A, SI70XX_READ_ID_PT2B,
689 	    buf, 8);
690 	if (error != 0) {
691 		aprint_error_dev(self, "Failed to read second part of ID: %d\n",
692 		    error);
693 		ecount++;
694 	}
695 	model = testcrcpt2[0] = buf[0];
696 	testcrcpt2[1] = buf[1];
697 	testcrcpt2[2] = buf[3];
698 	testcrcpt2[3] = buf[4];
699 	readcrc2 = buf[5];
700 	crc2 = si70xx_crc(testcrcpt2, 4);
701 	/* It is even stranger for this part of the serial number.  A "real"
702 	 * SI70XX will have a single CRC for the entire second part, but
703 	 * an HTU21D has a CRC for each word in this case.
704 	 *
705 	 * The datasheet actually agrees with the HTU21D case, and not the "real"
706 	 * chip.
707 	 */
708 	validcrcpt2 = (readcrc2 == crc2);
709 	if (! validcrcpt2) {
710 		validcrcpt2 = (si70xx_crc(&testcrcpt2[0],2) == buf[2] &&
711 		    si70xx_crc(&testcrcpt2[2],2) == buf[5]);
712 		DPRINTF(sc, 2, ("%s: Part 2 SN CRC was not valid for real type, "
713 		    "check clone: %d\n", device_xname(sc->sc_dev), validcrcpt2));
714 	}
715 
716 	DPRINTF(sc, 2, ("%s: read 2 values: %02x%02x%02x%02x%02x%02x - %02x -- %d\n",
717 	    device_xname(sc->sc_dev), buf[0], buf[1], buf[2],
718 	    buf[3], buf[4], buf[5], crc2, validcrcpt2));
719 
720 	error = si70xx_cmd2(sc, SI70XX_READ_FW_VERA, SI70XX_READ_FW_VERB,
721 	    buf, 8);
722 
723 	if (error) {
724 		aprint_error_dev(self, "Failed to read firmware version: Error %d\n",
725 		    error);
726 		sc->sc_nofw = true;
727 	}
728 	if (! sc->sc_nofw) {
729 		fwversion = buf[0];
730 		DPRINTF(sc, 2, ("%s: read fw values: %#x\n", device_xname(sc->sc_dev),
731 		    fwversion));
732 	}
733 
734 	error = si70xx_cmd1(sc, SI70XX_READ_HEATER_REG, &heaterregister, 1);
735 
736 	if (error) {
737 		aprint_error_dev(self, "Failed to read heater register: Error %d\n",
738 		    error);
739 		sc->sc_noheater = true;
740 	}
741 
742 	error = si70xx_update_status(sc);
743 
744 	iic_release_bus(sc->sc_tag, 0);
745 
746 	if ((error = si70xx_sysctl_init(sc)) != 0) {
747 		aprint_error_dev(self, "Can't setup sysctl tree (%d)\n", error);
748 		goto out;
749 	}
750 
751 	if (error != 0) {
752 		aprint_error_dev(self, "Failed to update status: %x\n", error);
753 		aprint_error_dev(self, "Unable to setup device\n");
754 		goto out;
755 	}
756 
757 	for (i = 0; i < sc->sc_numsensors; i++) {
758 		strlcpy(sc->sc_sensors[i].desc, si70xx_sensors[i].desc,
759 		    sizeof(sc->sc_sensors[i].desc));
760 
761 		sc->sc_sensors[i].units = si70xx_sensors[i].type;
762 		sc->sc_sensors[i].state = ENVSYS_SINVALID;
763 
764 		DPRINTF(sc, 2, ("%s: registering sensor %d (%s)\n", __func__, i,
765 		    sc->sc_sensors[i].desc));
766 
767 		error = sysmon_envsys_sensor_attach(sc->sc_sme,
768 		    &sc->sc_sensors[i]);
769 		if (error) {
770 			aprint_error_dev(self,
771 			    "Unable to attach sensor %d: %d\n", i, error);
772 			sc->sc_sme = NULL;
773 			goto out;
774 		}
775 	}
776 
777 	sc->sc_sme->sme_name = device_xname(sc->sc_dev);
778 	sc->sc_sme->sme_cookie = sc;
779 	sc->sc_sme->sme_refresh = si70xx_refresh;
780 
781 	DPRINTF(sc, 2, ("si70xx_attach: registering with envsys\n"));
782 
783 	if (sysmon_envsys_register(sc->sc_sme)) {
784 		aprint_error_dev(self,
785 			"unable to register with sysmon\n");
786 		sysmon_envsys_destroy(sc->sc_sme);
787 		sc->sc_sme = NULL;
788 		return;
789 	}
790 
791 	char modelstr[64];
792 	switch (model) {
793 	case 0:
794 	case 0xff:
795 		snprintf(modelstr, sizeof(modelstr), "Engineering Sample");
796 		break;
797 	case 13:
798 	case 20:
799 	case 21:
800 		snprintf(modelstr, sizeof(modelstr), "SI70%d", model);
801 		break;
802 	default:
803 		snprintf(modelstr, sizeof(modelstr), "Unknown model %d (maybe an HTU21D)", model);
804 		break;
805 	}
806 
807 	const char *fwversionstr;
808 	switch (fwversion) {
809 	case 0xff:
810 		fwversionstr = "1.0";
811 		break;
812 	case 0x20:
813 		fwversionstr = "2.0";
814 		break;
815 	default:
816 		fwversionstr = "unknown";
817 		break;
818 	}
819 
820 	aprint_normal_dev(self, "Silicon Labs Model: %s, "
821 	    "Firmware version: %s, "
822 	    "Serial number: %02x%02x%02x%02x%02x%02x%02x%02x%s",
823 	    modelstr, fwversionstr, testcrcpt1[0], testcrcpt1[1],
824 	    testcrcpt1[2], testcrcpt1[3], testcrcpt2[0], testcrcpt2[1],
825 	    testcrcpt2[2], testcrcpt2[3],
826 	    (validcrcpt1 && validcrcpt2) ? "\n" : " (bad crc)\n");
827 	return;
828 out:
829 	sysmon_envsys_destroy(sc->sc_sme);
830 	sc->sc_sme = NULL;
831 }
832 
833 static int
834 si70xx_exec(struct si70xx_sc *sc, uint8_t cmd, envsys_data_t *edata)
835 {
836 	int error;
837 	int xdelay;
838 	const char *name;
839 	int64_t mul, offs;
840 	uint8_t buf[3];
841 
842 	switch (cmd) {
843 	case SI70XX_MEASURE_RH_NOHOLD:
844 		/*
845 		 * The published conversion for RH is: %RH =
846 		 * ((125 * RHCODE) / 65536) - 6
847 		 *
848 		 * The sysmon infrastructure for RH wants %RH *
849 		 * 10^6 The result will fit in 32 bits, but
850 		 * the intermediate values will not.
851 		 */
852 		mul = 125000000;
853 		offs = -6000000;
854 		/*
855 		 * Conversion times for %RH in ms
856 		 *
857 		 *        	Typical Max
858 		 * 12-bit	10.0	12.0
859 		 * 11-bit	 5.8	 7.0
860 		 * 10-bit	 3.7	 4.5
861 		 *  8-bit	 2.6	 3.1
862 		 *
863 		 * A call to read %RH will also read temperature.  The
864 		 * conversion time will be the amount of time above
865 		 * plus the amount of time for temperature below
866 		 */
867 		xdelay = 10500;
868 		name = "RH";
869 		break;
870 	case SI70XX_MEASURE_TEMP_NOHOLD:
871 		/*
872 		 * The published conversion for temp is:
873 		 * degree C = ((175.72 * TEMPCODE) / 65536) -
874 		 * 46.85
875 		 *
876 		 * The sysmon infrastructure for temp wants
877 		 * microkelvin.  This is simple, as degree C
878 		 * converts directly with K with simple
879 		 * addition. The result will fit in 32 bits,
880 		 * but the intermediate values will not.
881 		 */
882 		mul = 175720000;
883 		offs = 226300000;
884 		/*
885 		 * Conversion times for temperature in ms
886 	 	 *
887 		 *		Typical	Max
888 		 * 14-bit	7.0	10.8
889 		 * 13-bit	4.0	 6.2
890 		 * 12-bit	2.4	 3.8
891 		 * 11-bit	1.5	 2.4
892 		 */
893 		xdelay = 4750;
894 		name = "TEMP";
895 		break;
896 	default:
897 		return EINVAL;
898 	}
899 
900 #if HAVE_I2C_EXECV
901 	memset(buf, 0, sizeof(buf));
902 	error = iic_execv(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
903 	    &cmd, 1, buf, sizeof(buf), 0, I2C_ATTR_CLOCKSTRETCH,
904 	    sc->sc_clockstretch, I2C_ATTR_EOL);
905 #else
906 	/*
907 	 * The lower level driver must support the ability to
908 	 * do a zero length read, otherwise this breaks
909 	 */
910 	error = si70xx_cmd1(sc, cmd, buf, 0);
911 	if (error) {
912 		DPRINTF(sc, 2, ("%s: Failed to read NO HOLD %s %d %d\n",
913 		    device_xname(sc->sc_dev), name, 1, error));
914 		return error;
915 	}
916 
917 	/*
918 	 * It will probably be at least this long... we would
919 	 * not have to do this sort of thing if clock
920 	 * stretching worked.  Even this is a problem for the
921 	 * RPI without a patch to remove a [apparently] not
922 	 * needed KASSERT()
923 	 */
924 	delay(xdelay);
925 
926 	for (int aint = 0; aint < sc->sc_readattempts; aint++) {
927 		error = si70xx_cmd0(sc, buf, sizeof(buf));
928 		if (error == 0)
929 			break;
930 		DPRINTF(sc, 2, ("%s: Failed to read NO HOLD RH"
931 		    " %d %d\n", device_xname(sc->sc_dev), 2, error));
932 		delay(1000);
933 	}
934 #endif
935 
936 	DPRINTF(sc, 2, ("%s: %s values: %02x%02x%02x - %02x\n",
937 	    device_xname(sc->sc_dev), name, buf[0], buf[1], buf[2],
938 	    si70xx_crc(buf, 2)));
939 
940 	uint8_t crc;
941 	if (sc->sc_ignorecrc) {
942 		crc = buf[2];
943 	} else {
944 		crc = si70xx_crc(buf, 2);
945 	}
946 
947 	if (crc != buf[2]) {
948 		DPRINTF(sc, 2, ("%s: Bad CRC for %s: %#x and %#x\n",
949 		    device_xname(sc->sc_dev), name, crc, buf[2]));
950 		return EINVAL;
951 	}
952 
953 	uint16_t val16 = (buf[0] << 8) | buf[1];
954 	uint64_t val64 = ((mul * val16) >> 16) + offs;
955 	DPRINTF(sc, 2, ("%s: %s calculated values: %x %#jx\n",
956 	    device_xname(sc->sc_dev), name, val16, (uintmax_t)val64));
957 	edata->value_cur = (uint32_t) val64;
958 	edata->state = ENVSYS_SVALID;
959 	return 0;
960 }
961 
962 static void
963 si70xx_refresh(struct sysmon_envsys * sme, envsys_data_t * edata)
964 {
965 	struct si70xx_sc *sc;
966 	int 		error;
967 
968 	sc = sme->sme_cookie;
969 	edata->state = ENVSYS_SINVALID;
970 
971 	mutex_enter(&sc->sc_mutex);
972 	error = iic_acquire_bus(sc->sc_tag, 0);
973 	if (error) {
974 		DPRINTF(sc, 2, ("%s: Could not acquire i2c bus: %x\n",
975 		    device_xname(sc->sc_dev), error));
976 		goto out;
977 	}
978 	error = si70xx_update_status(sc);
979 	if (error) {
980 		DPRINTF(sc, 2, ("%s: Failed to update status in refresh %d\n",
981 		    device_xname(sc->sc_dev), error));
982 		goto out1;
983 	}
984 	switch (edata->sensor) {
985 	case SI70XX_HUMIDITY_SENSOR:
986 		error = si70xx_exec(sc, SI70XX_MEASURE_RH_NOHOLD, edata);
987 		break;
988 
989 	case SI70XX_TEMP_SENSOR:
990 		error = si70xx_exec(sc, SI70XX_MEASURE_TEMP_NOHOLD, edata);
991 		break;
992 	default:
993 		error = EINVAL;
994 		break;
995 	}
996 
997 	if (error) {
998 		DPRINTF(sc, 2, ("%s: Failed to get new status in refresh %d\n",
999 		    device_xname(sc->sc_dev), error));
1000 	}
1001 out1:
1002 	iic_release_bus(sc->sc_tag, 0);
1003 out:
1004 	mutex_exit(&sc->sc_mutex);
1005 }
1006 
1007 static int
1008 si70xx_detach(device_t self, int flags)
1009 {
1010 	struct si70xx_sc *sc;
1011 
1012 	sc = device_private(self);
1013 
1014 	mutex_enter(&sc->sc_mutex);
1015 
1016 	/* Remove the sensors */
1017 	if (sc->sc_sme != NULL)
1018 		sysmon_envsys_unregister(sc->sc_sme);
1019 	mutex_exit(&sc->sc_mutex);
1020 
1021 	/* Remove the sysctl tree */
1022 	sysctl_teardown(&sc->sc_si70xxlog);
1023 
1024 	/* Remove the mutex */
1025 	mutex_destroy(&sc->sc_mutex);
1026 
1027 	return 0;
1028 }
1029 
1030 MODULE(MODULE_CLASS_DRIVER, si70xxtemp, "iic,sysmon_envsys");
1031 
1032 #ifdef _MODULE
1033 #include "ioconf.c"
1034 #endif
1035 
1036 static int
1037 si70xxtemp_modcmd(modcmd_t cmd, void *opaque)
1038 {
1039 
1040 	switch (cmd) {
1041 	case MODULE_CMD_INIT:
1042 #ifdef _MODULE
1043 		return config_init_component(cfdriver_ioconf_si70xxtemp,
1044 		    cfattach_ioconf_si70xxtemp, cfdata_ioconf_si70xxtemp);
1045 #else
1046 		return 0;
1047 #endif
1048 	case MODULE_CMD_FINI:
1049 #ifdef _MODULE
1050 		return config_fini_component(cfdriver_ioconf_si70xxtemp,
1051 		      cfattach_ioconf_si70xxtemp, cfdata_ioconf_si70xxtemp);
1052 #else
1053 		return 0;
1054 #endif
1055 	default:
1056 		return ENOTTY;
1057 	}
1058 }
1059