xref: /netbsd-src/sys/dev/i2c/si70xx.c (revision be8e43b169398f1f020f7c25bb5ffc4fc04f58ed)
1 /*	$NetBSD: si70xx.c,v 1.12 2025/01/23 19:13:19 brad 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 1.12 2025/01/23 19:13:19 brad 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 	case SI70XX_MEASURE_RH_HOLD:
218 	case SI70XX_MEASURE_TEMP_HOLD:
219 		return I2C_OP_READ_WITH_STOP;
220 	case SI70XX_WRITE_USER_REG_1:
221 	case SI70XX_WRITE_HEATER_REG:
222 	case SI70XX_RESET:
223 		return I2C_OP_WRITE_WITH_STOP;
224 	case SI70XX_MEASURE_RH_NOHOLD:
225 	case SI70XX_MEASURE_TEMP_NOHOLD:
226 		return len == 0 ? I2C_OP_WRITE : I2C_OP_READ_WITH_STOP;
227 	default:
228 		panic("%s: bad command %#x\n", __func__, cmd);
229 		return 0;
230 	}
231 }
232 
233 static int
234 si70xx_cmd(i2c_tag_t tag, i2c_addr_t addr, uint8_t *cmd,
235     uint8_t clen, uint8_t *buf, size_t blen)
236 {
237 	uint8_t dir;
238 	if (clen == 0)
239 		dir = blen == 0 ? I2C_OP_READ : I2C_OP_READ_WITH_STOP;
240 	else
241 		dir = si70xx_dir(cmd[0], blen);
242 
243 	if (dir == I2C_OP_READ || dir == I2C_OP_READ_WITH_STOP)
244 		memset(buf, 0, blen);
245 
246 	return iic_exec(tag, dir, addr, cmd, clen, buf, blen, 0);
247 }
248 
249 static int
250 si70xx_cmd0(struct si70xx_sc *sc, uint8_t *buf, size_t blen)
251 {
252 	return si70xx_cmd(sc->sc_tag, sc->sc_addr, NULL, 0, buf, blen);
253 }
254 
255 static int
256 si70xx_cmd1(struct si70xx_sc *sc, uint8_t cmd, uint8_t *buf, size_t blen)
257 {
258 	return si70xx_cmd(sc->sc_tag, sc->sc_addr, &cmd, 1, buf, blen);
259 }
260 
261 static int
262 si70xx_cmd2(struct si70xx_sc *sc, uint8_t cmd1, uint8_t cmd2, uint8_t *buf,
263     size_t blen)
264 {
265 	uint8_t cmd[] = { cmd1, cmd2 };
266 	return si70xx_cmd(sc->sc_tag, sc->sc_addr, cmd, __arraycount(cmd),
267 	    buf, blen);
268 }
269 
270 static int
271 si70xx_set_heateron(struct si70xx_sc * sc)
272 {
273 	int error;
274 	uint8_t userregister;
275 
276 	error = iic_acquire_bus(sc->sc_tag, 0);
277 	if (error) {
278 		DPRINTF(sc, 2, ("%s:%s: Failed to acquire bus: %d\n",
279 		    device_xname(sc->sc_dev), __func__, error));
280 		return error;
281 	}
282 
283 	error = si70xx_cmd1(sc, SI70XX_READ_USER_REG_1, &userregister, 1);
284 	if (error) {
285 		DPRINTF(sc, 2, ("%s: Failed to read user register 1: %d\n",
286 		    device_xname(sc->sc_dev), error));
287 		goto out;
288 	}
289 
290 	DPRINTF(sc, 2, ("%s:%s: reg 1 values before: %#x\n",
291 	    device_xname(sc->sc_dev), __func__, userregister));
292 	if (sc->sc_heateron) {
293 		userregister |= SI70XX_HTRE_MASK;
294 	} else {
295 		userregister &= ~SI70XX_HTRE_MASK;
296 	}
297 	DPRINTF(sc, 2, ("%s:%s: user reg 1 values after: %#x\n",
298 	    device_xname(sc->sc_dev), __func__, userregister));
299 
300 	error = si70xx_cmd1(sc, SI70XX_WRITE_USER_REG_1, &userregister, 1);
301 	if (error) {
302 		DPRINTF(sc, 2, ("%s: Failed to write user register 1: %d\n",
303 		    device_xname(sc->sc_dev), error));
304 	}
305 out:
306 	iic_release_bus(sc->sc_tag, 0);
307 	return error;
308 }
309 
310 static int
311 si70xx_set_resolution(struct si70xx_sc * sc, size_t index)
312 {
313 	int error;
314 	uint8_t userregister;
315 
316 	error = iic_acquire_bus(sc->sc_tag, 0);
317 	if (error) {
318 		DPRINTF(sc, 2, ("%s: Failed to acquire bus: %d\n",
319 		    device_xname(sc->sc_dev), error));
320 		return error;
321 	}
322 
323 	error = si70xx_cmd1(sc, SI70XX_READ_USER_REG_1, &userregister, 1);
324 	if (error) {
325 		DPRINTF(sc, 2, ("%s: Failed to read user register 1: %d\n",
326 		    device_xname(sc->sc_dev), error));
327 		goto out;
328 	}
329 
330 	DPRINTF(sc, 2, ("%s:%s: reg 1 values before: %#x\n",
331 	    device_xname(sc->sc_dev), __func__, userregister));
332 	userregister &= (~SI70XX_RESOLUTION_MASK);
333 	userregister |= si70xx_resolutions[index].num;
334 	DPRINTF(sc, 2, ("%s:%s: reg 1 values after: %#x\n",
335 	    device_xname(sc->sc_dev), __func__, userregister));
336 
337 	error = si70xx_cmd1(sc, SI70XX_WRITE_USER_REG_1, &userregister, 1);
338 	if (error) {
339 		DPRINTF(sc, 2, ("%s: Failed to write user register 1: %d\n",
340 		    device_xname(sc->sc_dev), error));
341 	}
342 out:
343 	iic_release_bus(sc->sc_tag, 0);
344 	return error;
345 }
346 
347 static int
348 si70xx_set_heatervalue(struct si70xx_sc * sc, size_t index)
349 {
350 	int error;
351 	uint8_t heaterregister;
352 
353 	error = iic_acquire_bus(sc->sc_tag, 0);
354 	if (error) {
355 		DPRINTF(sc, 2, ("%s: Failed to acquire bus: %d\n",
356 		    device_xname(sc->sc_dev), error));
357 		return error;
358 	}
359 	error = si70xx_cmd1(sc, SI70XX_READ_HEATER_REG, &heaterregister, 1);
360 	if (error) {
361 		DPRINTF(sc, 2, ("%s: Failed to read heater register: %d\n",
362 		    device_xname(sc->sc_dev), error));
363 		goto out;
364 	}
365 
366 	DPRINTF(sc, 2, ("%s:%s: heater values before: %#x\n",
367 	    device_xname(sc->sc_dev), __func__, heaterregister));
368 	heaterregister &= ~SI70XX_HEATER_MASK;
369 	heaterregister |= si70xx_heatervalues[index];
370 	DPRINTF(sc, 2, ("%s:%s: heater values after: %#x\n",
371 	    device_xname(sc->sc_dev), __func__, heaterregister));
372 
373 	error = si70xx_cmd1(sc, SI70XX_WRITE_HEATER_REG, &heaterregister, 1);
374 	if (error) {
375 		DPRINTF(sc, 2, ("%s: Failed to write heater register: %d\n",
376 		    device_xname(sc->sc_dev), error));
377 	}
378 out:
379 	iic_release_bus(sc->sc_tag, 0);
380 	return error;
381 }
382 
383 static int
384 si70xx_update_heater(struct si70xx_sc *sc)
385 {
386 	size_t i;
387 	int error;
388 	uint8_t heaterregister;
389 
390 	error = si70xx_cmd1(sc, SI70XX_READ_HEATER_REG, &heaterregister, 1);
391 	if (error) {
392 		DPRINTF(sc, 2, ("%s: Failed to read heater register: %d\n",
393 		    device_xname(sc->sc_dev), error));
394 		return error;
395 	}
396 
397 	DPRINTF(sc, 2, ("%s: read heater reg values: %02x\n",
398 	    device_xname(sc->sc_dev), heaterregister));
399 
400 	uint8_t heat = heaterregister & SI70XX_HEATER_MASK;
401 	for (i = 0; i < __arraycount(si70xx_heatervalues); i++) {
402 		if (si70xx_heatervalues[i] == heat)
403 			break;
404 	}
405 	sc->sc_heaterval = i != __arraycount(si70xx_heatervalues) ? i : 0;
406 	return 0;
407 }
408 
409 static int
410 si70xx_update_user(struct si70xx_sc *sc)
411 {
412 	size_t i;
413 	int error;
414 	uint8_t userregister;
415 
416 	error = si70xx_cmd1(sc, SI70XX_READ_USER_REG_1, &userregister, 1);
417 	if (error) {
418 		DPRINTF(sc, 2, ("%s: Failed to read user register 1: %d\n",
419 		    device_xname(sc->sc_dev), error));
420 		return error;
421 	}
422 	DPRINTF(sc, 2, ("%s: read user reg 1 values: %#x\n",
423 	    device_xname(sc->sc_dev), userregister));
424 
425 	uint8_t res = userregister & SI70XX_RESOLUTION_MASK;
426 	for (i = 0; i < __arraycount(si70xx_resolutions); i++) {
427 		if (si70xx_resolutions[i].num == res)
428 			break;
429 	}
430 
431 	if (i != __arraycount(si70xx_resolutions)) {
432 		memcpy(sc->sc_resolution, si70xx_resolutions[i].text,
433 		    SI70XX_RES_NAME);
434 	} else {
435 		snprintf(sc->sc_resolution, SI70XX_RES_NAME, "%02x", res);
436 	}
437 
438 	sc->sc_vddok = (userregister & SI70XX_VDDS_MASK) == 0;
439 	sc->sc_heaterval = userregister & SI70XX_HTRE_MASK;
440 	return 0;
441 }
442 
443 static int
444 si70xx_update_status(struct si70xx_sc *sc)
445 {
446 	int error1 = si70xx_update_user(sc);
447 	int error2 = 0;
448 	if (! sc->sc_noheater) {
449 		error2 = si70xx_update_heater(sc);
450 	}
451 	return error1 ? error1 : error2;
452 }
453 
454 static	uint8_t
455 si70xx_crc(uint8_t * data, size_t size)
456 {
457 	uint8_t crc = 0;
458 
459 	for (size_t i = 0; i < size; i++) {
460 		crc ^= data[i];
461 		for (size_t j = 8; j > 0; j--) {
462 			if (crc & 0x80)
463 				crc = (crc << 1) ^ 0x131;
464 			else
465 				crc <<= 1;
466 		}
467 	}
468 	return crc;
469 }
470 
471 static int
472 si70xx_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug)
473 {
474 	uint8_t reg = SI70XX_READ_USER_REG_1;
475 	uint8_t buf;
476 	int error;
477 
478 	error = si70xx_cmd(tag, addr, &reg, 1, &buf, 1);
479 	if (matchdebug) {
480 		printf("poke X 1: %d\n", error);
481 	}
482 	return error;
483 }
484 
485 static int
486 si70xx_sysctl_init(struct si70xx_sc *sc)
487 {
488 	int error;
489 	const struct sysctlnode *cnode;
490 	int sysctlroot_num;
491 
492 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
493 	    0, CTLTYPE_NODE, device_xname(sc->sc_dev),
494 	    SYSCTL_DESCR("si70xx controls"), NULL, 0, NULL, 0, CTL_HW,
495 	    CTL_CREATE, CTL_EOL)) != 0)
496 		return error;
497 
498 	sysctlroot_num = cnode->sysctl_num;
499 
500 #ifdef SI70XX_DEBUG
501 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
502 	    CTLFLAG_READWRITE, CTLTYPE_INT, "debug",
503 	    SYSCTL_DESCR("Debug level"), si70xx_verify_sysctl, 0,
504 	    &sc->sc_si70xxdebug, 0, CTL_HW, sysctlroot_num, CTL_CREATE,
505 	    CTL_EOL)) != 0)
506 		return error;
507 
508 #endif
509 
510 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
511 	    CTLFLAG_READWRITE, CTLTYPE_BOOL, "clockstretch",
512 	    SYSCTL_DESCR("Use clock stretch commands for measurements"), NULL, 0,
513 	    &sc->sc_clockstretch, 0, CTL_HW, sysctlroot_num, CTL_CREATE,
514 	    CTL_EOL)) != 0)
515 		return error;
516 
517 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
518 	    CTLFLAG_READWRITE, CTLTYPE_INT, "readattempts",
519 	    SYSCTL_DESCR("The number of times to attempt to read the values"),
520 	    si70xx_verify_sysctl, 0, &sc->sc_readattempts, 0, CTL_HW,
521 	    sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
522 		return error;
523 
524 
525 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
526 	    CTLFLAG_READONLY, CTLTYPE_STRING, "resolutions",
527 	    SYSCTL_DESCR("Valid resolutions"), 0, 0,
528 	    __UNCONST(si70xx_resolution_names),
529 	    sizeof(si70xx_resolution_names) + 1,
530 	    CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
531 		return error;
532 
533 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
534 	    CTLFLAG_READWRITE, CTLTYPE_STRING, "resolution",
535 	    SYSCTL_DESCR("Resolution of RH and Temp"),
536 	    si70xx_verify_sysctl_resolution, 0, (void *) sc,
537 	    SI70XX_RES_NAME, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
538 		return error;
539 
540 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
541 	    CTLFLAG_READWRITE, CTLTYPE_BOOL, "ignorecrc",
542 	    SYSCTL_DESCR("Ignore the CRC byte"), NULL, 0, &sc->sc_ignorecrc,
543 	    0, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
544 		return error;
545 
546 	if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
547 	    CTLFLAG_READONLY, CTLTYPE_BOOL, "vddok",
548 	    SYSCTL_DESCR("Vdd at least 1.9v"), NULL, 0, &sc->sc_vddok, 0,
549 	    CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
550 		return error;
551 
552 	if (! sc->sc_noheater) {
553 		if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
554 		    CTLFLAG_READWRITE, CTLTYPE_BOOL, "heateron",
555 		    SYSCTL_DESCR("Heater on"), si70xx_verify_sysctl_heateron, 0,
556 		    (void *)sc, 0, CTL_HW, sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
557 			return error;
558 
559 		if ((error = sysctl_createv(&sc->sc_si70xxlog, 0, NULL, &cnode,
560 		    CTLFLAG_READWRITE, CTLTYPE_INT, "heaterstrength",
561 		    SYSCTL_DESCR("Heater strength 1 to 6"),
562 		    si70xx_verify_sysctl_heatervalue, 0, (void *)sc, 0, CTL_HW,
563 		    sysctlroot_num, CTL_CREATE, CTL_EOL)) != 0)
564 			return error;
565 	}
566 
567 	return 0;
568 }
569 
570 static int
571 si70xx_match(device_t parent, cfdata_t match, void *aux)
572 {
573 	struct i2c_attach_args *ia = aux;
574 	int error, match_result;
575 	const bool matchdebug = false;
576 
577 	if (iic_use_direct_match(ia, match, NULL, &match_result))
578 		return match_result;
579 
580 	/* indirect config - check for configured address */
581 	if (ia->ia_addr != SI70XX_TYPICAL_ADDR)
582 		return 0;
583 
584 	/*
585 	 * Check to see if something is really at this i2c address. This will
586 	 * keep phantom devices from appearing
587 	 */
588 	if (iic_acquire_bus(ia->ia_tag, 0) != 0) {
589 		if (matchdebug)
590 			printf("in match acquire bus failed\n");
591 		return 0;
592 	}
593 
594 	error = si70xx_poke(ia->ia_tag, ia->ia_addr, matchdebug);
595 	iic_release_bus(ia->ia_tag, 0);
596 
597 	return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0;
598 }
599 
600 static void
601 si70xx_attach(device_t parent, device_t self, void *aux)
602 {
603 	struct si70xx_sc *sc;
604 	struct i2c_attach_args *ia;
605 	int error, i;
606 	int ecount = 0;
607 	uint8_t buf[8];
608 	uint8_t testcrcpt1[4];
609 	uint8_t testcrcpt2[4];
610 	uint8_t crc1 = 0, crc2 = 0;
611 	bool validcrcpt1, validcrcpt2;
612 	uint8_t readcrc1 = 0, readcrc2 = 0;
613 	uint8_t fwversion = 0, model, heaterregister;
614 
615 	ia = aux;
616 	sc = device_private(self);
617 
618 	sc->sc_dev = self;
619 	sc->sc_tag = ia->ia_tag;
620 	sc->sc_addr = ia->ia_addr;
621 	sc->sc_si70xxdebug = 0;
622 	sc->sc_clockstretch = false;
623 	sc->sc_readattempts = 40;
624 	sc->sc_ignorecrc = false;
625 	sc->sc_sme = NULL;
626 	sc->sc_noheater = false;
627 	sc->sc_nofw = false;
628 
629 	aprint_normal("\n");
630 
631 	mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE);
632 	sc->sc_numsensors = __arraycount(si70xx_sensors);
633 
634 	if ((sc->sc_sme = sysmon_envsys_create()) == NULL) {
635 		aprint_error_dev(self,
636 		    "Unable to create sysmon structure\n");
637 		sc->sc_sme = NULL;
638 		return;
639 	}
640 
641 	error = iic_acquire_bus(sc->sc_tag, 0);
642 	if (error) {
643 		aprint_error_dev(self, "Could not acquire iic bus: %d\n",
644 		    error);
645 		goto out;
646 	}
647 	error = si70xx_cmd1(sc, SI70XX_RESET, NULL, 0);
648 	if (error != 0)
649 		aprint_error_dev(self, "Reset failed: %d\n", error);
650 
651 	delay(15000);	/* 15 ms max */
652 
653 	error = si70xx_cmd2(sc, SI70XX_READ_ID_PT1A, SI70XX_READ_ID_PT1B,
654 	    buf, 8);
655 	if (error) {
656 		aprint_error_dev(self, "Failed to read first part of ID: %d\n",
657 		    error);
658 		ecount++;
659 	}
660 	testcrcpt1[0] = buf[0];
661 	testcrcpt1[1] = buf[2];
662 	testcrcpt1[2] = buf[4];
663 	testcrcpt1[3] = buf[6];
664 	readcrc1 = buf[7];
665 	crc1 = si70xx_crc(testcrcpt1, 4);
666 	/* A "real" SI70xx has the CRC cover the entire first part of the
667 	 * serial number.  An HTU21D has the CRC broken out into each
668 	 * part of the serial number.
669 	 */
670 	validcrcpt1 = (readcrc1 == crc1);
671 	if (! validcrcpt1) {
672 		validcrcpt1 = (si70xx_crc(&testcrcpt1[0],1) == buf[1] &&
673 		    si70xx_crc(&testcrcpt1[1],1) == buf[3] &&
674 		    si70xx_crc(&testcrcpt1[2],1) == buf[5] &&
675 		    si70xx_crc(&testcrcpt1[3],1) == buf[7]);
676 		DPRINTF(sc, 2, ("%s: Part 1 SN CRC was not valid for real type, "
677 		    "check clone: %d\n", device_xname(sc->sc_dev), validcrcpt1));
678 	}
679 
680 	DPRINTF(sc, 2, ("%s: read 1 values: %02x%02x%02x%02x%02x%02x%02x%02x "
681 	    "- %02x -- %d\n", device_xname(sc->sc_dev), buf[0], buf[1],
682 	    buf[2], buf[3], buf[4], buf[5], buf[6], buf[7],
683 	    crc1, validcrcpt1));
684 
685 	error = si70xx_cmd2(sc, SI70XX_READ_ID_PT2A, SI70XX_READ_ID_PT2B,
686 	    buf, 6);
687 	if (error != 0) {
688 		aprint_error_dev(self, "Failed to read second part of ID: %d\n",
689 		    error);
690 		ecount++;
691 	}
692 	model = testcrcpt2[0] = buf[0];
693 	testcrcpt2[1] = buf[1];
694 	testcrcpt2[2] = buf[3];
695 	testcrcpt2[3] = buf[4];
696 	readcrc2 = buf[5];
697 	crc2 = si70xx_crc(testcrcpt2, 4);
698 	/* It is even stranger for this part of the serial number.  A "real"
699 	 * SI70XX will have a single CRC for the entire second part, but
700 	 * an HTU21D has a CRC for each word in this case.
701 	 *
702 	 * The datasheet actually agrees with the HTU21D case, and not the "real"
703 	 * chip.
704 	 */
705 	validcrcpt2 = (readcrc2 == crc2);
706 	if (! validcrcpt2) {
707 		validcrcpt2 = (si70xx_crc(&testcrcpt2[0],2) == buf[2] &&
708 		    si70xx_crc(&testcrcpt2[2],2) == buf[5]);
709 		DPRINTF(sc, 2, ("%s: Part 2 SN CRC was not valid for real type, "
710 		    "check clone: %d\n", device_xname(sc->sc_dev), validcrcpt2));
711 	}
712 
713 	DPRINTF(sc, 2, ("%s: read 2 values: %02x%02x%02x%02x%02x%02x - %02x -- %d\n",
714 	    device_xname(sc->sc_dev), buf[0], buf[1], buf[2],
715 	    buf[3], buf[4], buf[5], crc2, validcrcpt2));
716 
717 	error = si70xx_cmd2(sc, SI70XX_READ_FW_VERA, SI70XX_READ_FW_VERB,
718 	    buf, 1);
719 
720 	if (error) {
721 		aprint_error_dev(self, "Failed to read firmware version: Error %d\n",
722 		    error);
723 		sc->sc_nofw = true;
724 	}
725 	if (! sc->sc_nofw) {
726 		fwversion = buf[0];
727 		DPRINTF(sc, 2, ("%s: read fw values: %#x\n", device_xname(sc->sc_dev),
728 		    fwversion));
729 	}
730 
731 	error = si70xx_cmd1(sc, SI70XX_READ_HEATER_REG, &heaterregister, 1);
732 
733 	if (error) {
734 		aprint_error_dev(self, "Failed to read heater register: Error %d\n",
735 		    error);
736 		sc->sc_noheater = true;
737 	}
738 
739 	error = si70xx_update_status(sc);
740 
741 	iic_release_bus(sc->sc_tag, 0);
742 
743 	if ((error = si70xx_sysctl_init(sc)) != 0) {
744 		aprint_error_dev(self, "Can't setup sysctl tree (%d)\n", error);
745 		goto out;
746 	}
747 
748 	if (error != 0) {
749 		aprint_error_dev(self, "Failed to update status: %x\n", error);
750 		aprint_error_dev(self, "Unable to setup device\n");
751 		goto out;
752 	}
753 
754 	for (i = 0; i < sc->sc_numsensors; i++) {
755 		strlcpy(sc->sc_sensors[i].desc, si70xx_sensors[i].desc,
756 		    sizeof(sc->sc_sensors[i].desc));
757 
758 		sc->sc_sensors[i].units = si70xx_sensors[i].type;
759 		sc->sc_sensors[i].state = ENVSYS_SINVALID;
760 
761 		DPRINTF(sc, 2, ("%s: registering sensor %d (%s)\n", __func__, i,
762 		    sc->sc_sensors[i].desc));
763 
764 		error = sysmon_envsys_sensor_attach(sc->sc_sme,
765 		    &sc->sc_sensors[i]);
766 		if (error) {
767 			aprint_error_dev(self,
768 			    "Unable to attach sensor %d: %d\n", i, error);
769 			sc->sc_sme = NULL;
770 			goto out;
771 		}
772 	}
773 
774 	sc->sc_sme->sme_name = device_xname(sc->sc_dev);
775 	sc->sc_sme->sme_cookie = sc;
776 	sc->sc_sme->sme_refresh = si70xx_refresh;
777 
778 	DPRINTF(sc, 2, ("si70xx_attach: registering with envsys\n"));
779 
780 	if (sysmon_envsys_register(sc->sc_sme)) {
781 		aprint_error_dev(self,
782 			"unable to register with sysmon\n");
783 		sysmon_envsys_destroy(sc->sc_sme);
784 		sc->sc_sme = NULL;
785 		return;
786 	}
787 
788 	char modelstr[64];
789 	switch (model) {
790 	case 0:
791 	case 0xff:
792 		snprintf(modelstr, sizeof(modelstr), "Engineering Sample");
793 		break;
794 	case 13:
795 	case 20:
796 	case 21:
797 		snprintf(modelstr, sizeof(modelstr), "SI70%d", model);
798 		break;
799 	default:
800 		snprintf(modelstr, sizeof(modelstr), "Unknown model %d (maybe an HTU21D)", model);
801 		break;
802 	}
803 
804 	const char *fwversionstr;
805 	switch (fwversion) {
806 	case 0xff:
807 		fwversionstr = "1.0";
808 		break;
809 	case 0x20:
810 		fwversionstr = "2.0";
811 		break;
812 	default:
813 		fwversionstr = "unknown";
814 		break;
815 	}
816 
817 	aprint_normal_dev(self, "Silicon Labs Model: %s, "
818 	    "Firmware version: %s, "
819 	    "Serial number: %02x%02x%02x%02x%02x%02x%02x%02x%s",
820 	    modelstr, fwversionstr, testcrcpt1[0], testcrcpt1[1],
821 	    testcrcpt1[2], testcrcpt1[3], testcrcpt2[0], testcrcpt2[1],
822 	    testcrcpt2[2], testcrcpt2[3],
823 	    (validcrcpt1 && validcrcpt2) ? "\n" : " (bad crc)\n");
824 	return;
825 out:
826 	sysmon_envsys_destroy(sc->sc_sme);
827 	sc->sc_sme = NULL;
828 }
829 
830 static int
831 si70xx_exec(struct si70xx_sc *sc, uint8_t cmd, envsys_data_t *edata)
832 {
833 	int error;
834 	int xdelay;
835 	const char *name;
836 	int64_t mul, offs;
837 	uint8_t buf[3];
838 
839 	switch (cmd) {
840 	case SI70XX_MEASURE_RH_NOHOLD:
841 	case SI70XX_MEASURE_RH_HOLD:
842 		/*
843 		 * The published conversion for RH is: %RH =
844 		 * ((125 * RHCODE) / 65536) - 6
845 		 *
846 		 * The sysmon infrastructure for RH wants %RH *
847 		 * 10^6 The result will fit in 32 bits, but
848 		 * the intermediate values will not.
849 		 */
850 		mul = 125000000;
851 		offs = -6000000;
852 		/*
853 		 * Conversion times for %RH in ms
854 		 *
855 		 *        	Typical Max
856 		 * 12-bit	10.0	12.0
857 		 * 11-bit	 5.8	 7.0
858 		 * 10-bit	 3.7	 4.5
859 		 *  8-bit	 2.6	 3.1
860 		 *
861 		 * A call to read %RH will also read temperature.  The
862 		 * conversion time will be the amount of time above
863 		 * plus the amount of time for temperature below
864 		 */
865 		xdelay = 10500;
866 		name = "RH";
867 		break;
868 	case SI70XX_MEASURE_TEMP_NOHOLD:
869 	case SI70XX_MEASURE_TEMP_HOLD:
870 		/*
871 		 * The published conversion for temp is:
872 		 * degree C = ((175.72 * TEMPCODE) / 65536) -
873 		 * 46.85
874 		 *
875 		 * The sysmon infrastructure for temp wants
876 		 * microkelvin.  This is simple, as degree C
877 		 * converts directly with K with simple
878 		 * addition. The result will fit in 32 bits,
879 		 * but the intermediate values will not.
880 		 */
881 		mul = 175720000;
882 		offs = 226300000;
883 		/*
884 		 * Conversion times for temperature in ms
885 	 	 *
886 		 *		Typical	Max
887 		 * 14-bit	7.0	10.8
888 		 * 13-bit	4.0	 6.2
889 		 * 12-bit	2.4	 3.8
890 		 * 11-bit	1.5	 2.4
891 		 */
892 		xdelay = 4750;
893 		name = "TEMP";
894 		break;
895 	default:
896 		return EINVAL;
897 	}
898 
899 	if (sc->sc_clockstretch) {
900 		error = si70xx_cmd1(sc, cmd, buf, sizeof(buf));
901 		if (error) {
902 			DPRINTF(sc, 2, ("%s: Failed to read HOLD %s %d %d\n",
903 			    device_xname(sc->sc_dev), name, 1, error));
904 			return error;
905 		}
906 	} else {
907 		error = si70xx_cmd1(sc, cmd, NULL, 0);
908 		if (error) {
909 			DPRINTF(sc, 2, ("%s: Failed to read NO HOLD %s %d %d\n",
910 			    device_xname(sc->sc_dev), name, 1, error));
911 			return error;
912 		}
913 
914 		/*
915 		 * It will probably be at least this long... we would
916 		 * not have to do this sort of thing if clock
917 		 * stretching worked.  Even this is a problem for the
918 		 * RPI without a patch to remove a [apparently] not
919 		 * needed KASSERT()
920 		 */
921 		delay(xdelay);
922 
923 		for (int aint = 0; aint < sc->sc_readattempts; aint++) {
924 			error = si70xx_cmd0(sc, buf, sizeof(buf));
925 			if (error == 0)
926 				break;
927 			DPRINTF(sc, 2, ("%s: Failed to read NO HOLD RH"
928 			    " %d %d\n", device_xname(sc->sc_dev), 2, error));
929 			delay(1000);
930 		}
931 	}
932 
933 	DPRINTF(sc, 2, ("%s: %s values: %02x%02x%02x - %02x\n",
934 	    device_xname(sc->sc_dev), name, buf[0], buf[1], buf[2],
935 	    si70xx_crc(buf, 2)));
936 
937 	uint8_t crc;
938 	if (sc->sc_ignorecrc) {
939 		crc = buf[2];
940 	} else {
941 		crc = si70xx_crc(buf, 2);
942 	}
943 
944 	if (crc != buf[2]) {
945 		DPRINTF(sc, 2, ("%s: Bad CRC for %s: %#x and %#x\n",
946 		    device_xname(sc->sc_dev), name, crc, buf[2]));
947 		return EINVAL;
948 	}
949 
950 	uint16_t val16 = (buf[0] << 8) | buf[1];
951 	uint64_t val64 = ((mul * val16) >> 16) + offs;
952 	DPRINTF(sc, 2, ("%s: %s calculated values: %x %#jx\n",
953 	    device_xname(sc->sc_dev), name, val16, (uintmax_t)val64));
954 	edata->value_cur = (uint32_t) val64;
955 	edata->state = ENVSYS_SVALID;
956 	return 0;
957 }
958 
959 static void
960 si70xx_refresh(struct sysmon_envsys * sme, envsys_data_t * edata)
961 {
962 	struct si70xx_sc *sc;
963 	int 		error;
964 
965 	sc = sme->sme_cookie;
966 	edata->state = ENVSYS_SINVALID;
967 
968 	mutex_enter(&sc->sc_mutex);
969 	error = iic_acquire_bus(sc->sc_tag, 0);
970 	if (error) {
971 		DPRINTF(sc, 2, ("%s: Could not acquire i2c bus: %x\n",
972 		    device_xname(sc->sc_dev), error));
973 		goto out;
974 	}
975 	error = si70xx_update_status(sc);
976 	if (error) {
977 		DPRINTF(sc, 2, ("%s: Failed to update status in refresh %d\n",
978 		    device_xname(sc->sc_dev), error));
979 		goto out1;
980 	}
981 	switch (edata->sensor) {
982 	case SI70XX_HUMIDITY_SENSOR:
983 		if (sc->sc_clockstretch)
984 			error = si70xx_exec(sc, SI70XX_MEASURE_RH_HOLD, edata);
985 		else
986 			error = si70xx_exec(sc, SI70XX_MEASURE_RH_NOHOLD, edata);
987 		break;
988 
989 	case SI70XX_TEMP_SENSOR:
990 		if (sc->sc_clockstretch)
991 			error = si70xx_exec(sc, SI70XX_MEASURE_TEMP_HOLD, edata);
992 		else
993 			error = si70xx_exec(sc, SI70XX_MEASURE_TEMP_NOHOLD, edata);
994 		break;
995 	default:
996 		error = EINVAL;
997 		break;
998 	}
999 
1000 	if (error) {
1001 		DPRINTF(sc, 2, ("%s: Failed to get new status in refresh %d\n",
1002 		    device_xname(sc->sc_dev), error));
1003 	}
1004 out1:
1005 	iic_release_bus(sc->sc_tag, 0);
1006 out:
1007 	mutex_exit(&sc->sc_mutex);
1008 }
1009 
1010 static int
1011 si70xx_detach(device_t self, int flags)
1012 {
1013 	struct si70xx_sc *sc;
1014 
1015 	sc = device_private(self);
1016 
1017 	mutex_enter(&sc->sc_mutex);
1018 
1019 	/* Remove the sensors */
1020 	if (sc->sc_sme != NULL)
1021 		sysmon_envsys_unregister(sc->sc_sme);
1022 	mutex_exit(&sc->sc_mutex);
1023 
1024 	/* Remove the sysctl tree */
1025 	sysctl_teardown(&sc->sc_si70xxlog);
1026 
1027 	/* Remove the mutex */
1028 	mutex_destroy(&sc->sc_mutex);
1029 
1030 	return 0;
1031 }
1032 
1033 MODULE(MODULE_CLASS_DRIVER, si70xxtemp, "iic,sysmon_envsys");
1034 
1035 #ifdef _MODULE
1036 #include "ioconf.c"
1037 #endif
1038 
1039 static int
1040 si70xxtemp_modcmd(modcmd_t cmd, void *opaque)
1041 {
1042 
1043 	switch (cmd) {
1044 	case MODULE_CMD_INIT:
1045 #ifdef _MODULE
1046 		return config_init_component(cfdriver_ioconf_si70xxtemp,
1047 		    cfattach_ioconf_si70xxtemp, cfdata_ioconf_si70xxtemp);
1048 #else
1049 		return 0;
1050 #endif
1051 	case MODULE_CMD_FINI:
1052 #ifdef _MODULE
1053 		return config_fini_component(cfdriver_ioconf_si70xxtemp,
1054 		      cfattach_ioconf_si70xxtemp, cfdata_ioconf_si70xxtemp);
1055 #else
1056 		return 0;
1057 #endif
1058 	default:
1059 		return ENOTTY;
1060 	}
1061 }
1062