xref: /netbsd-src/sys/dev/i2c/lm75.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
1 /*	$NetBSD: lm75.c,v 1.42 2021/03/01 04:40:39 rin Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: lm75.c,v 1.42 2021/03/01 04:40:39 rin Exp $");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/device.h>
44 #include <sys/kernel.h>
45 #include <sys/sysctl.h>
46 
47 #include <dev/sysmon/sysmonvar.h>
48 
49 #include <dev/i2c/i2cvar.h>
50 #include <dev/i2c/lm75reg.h>
51 
52 struct lmtemp_softc {
53 	device_t sc_dev;
54 	i2c_tag_t sc_tag;
55 	int sc_address;
56 	prop_dictionary_t sc_prop;
57 
58 	struct sysmon_envsys *sc_sme;
59 	envsys_data_t sc_sensor;
60 	int sc_tmax;
61 	uint32_t sc_smax, sc_smin, sc_scrit;
62 
63 	uint32_t (*sc_lmtemp_decode)(const uint8_t *, int);
64 	void (*sc_lmtemp_encode)(const uint32_t, uint8_t *, int);
65 };
66 
67 static int  lmtemp_match(device_t, cfdata_t, void *);
68 static void lmtemp_attach(device_t, device_t, void *);
69 
70 CFATTACH_DECL_NEW(lmtemp, sizeof(struct lmtemp_softc),
71 	lmtemp_match, lmtemp_attach, NULL, NULL);
72 
73 static void	lmtemp_refresh(struct sysmon_envsys *, envsys_data_t *);
74 static int	lmtemp_config_write(struct lmtemp_softc *, uint8_t);
75 static int	lmtemp_temp_write(struct lmtemp_softc *, uint8_t, uint32_t,
76 				int);
77 static int	lmtemp_temp_read(struct lmtemp_softc *, uint8_t, uint32_t *,
78 				int);
79 static uint32_t lmtemp_decode_lm75(const uint8_t *, int);
80 static uint32_t lmtemp_decode_ds75(const uint8_t *, int);
81 static uint32_t lmtemp_decode_lm77(const uint8_t *, int);
82 static void	lmtemp_encode_lm75(const uint32_t, uint8_t *, int);
83 static void	lmtemp_encode_ds75(const uint32_t, uint8_t *, int);
84 static void	lmtemp_encode_lm77(const uint32_t, uint8_t *, int);
85 static void	lmtemp_getlim_lm75(struct sysmon_envsys *, envsys_data_t *,
86 				sysmon_envsys_lim_t *, uint32_t *);
87 static void	lmtemp_getlim_lm77(struct sysmon_envsys *, envsys_data_t *,
88 				sysmon_envsys_lim_t *, uint32_t *);
89 static void	lmtemp_setlim_lm75(struct sysmon_envsys *, envsys_data_t *,
90 				sysmon_envsys_lim_t *, uint32_t *);
91 static void	lmtemp_setlim_lm77(struct sysmon_envsys *, envsys_data_t *,
92 				sysmon_envsys_lim_t *, uint32_t *);
93 
94 static void	lmtemp_setup_sysctl(struct lmtemp_softc *);
95 static int	sysctl_lm75_temp(SYSCTLFN_ARGS);
96 
97 enum {
98 	lmtemp_lm75 = 0,
99 	lmtemp_ds75 = 1,
100 	lmtemp_lm77 = 2,
101 };
102 
103 static const struct device_compatible_entry compat_data[] = {
104 	{ .compat = "national,lm75",	.value = lmtemp_lm75 },
105 	{ .compat = "i2c-lm75",		.value = lmtemp_lm75 },
106 	{ .compat = "lm75",		.value = lmtemp_lm75 },
107 
108 	/* XXX Linux treats ds1775 and ds75 differently. */
109 	{ .compat = "dallas,ds1775",	.value = lmtemp_ds75 },
110 	{ .compat = "ds1775",		.value = lmtemp_ds75 },
111 
112 	{ .compat = "national,lm77",	.value = lmtemp_lm77 },
113 
114 	/*
115 	 * see XXX in _attach() below: add code once non-lm75 matches are
116 	 * added here!
117 	 */
118 	DEVICE_COMPAT_EOL
119 };
120 
121 static const struct {
122 	const char *lmtemp_name;
123 	int lmtemp_addrmask;
124 	int lmtemp_addr;
125 	uint32_t (*lmtemp_decode)(const uint8_t *, int);
126 	void (*lmtemp_encode)(const uint32_t, uint8_t *, int);
127 	void (*lmtemp_getlim)(struct sysmon_envsys *, envsys_data_t *,
128 		sysmon_envsys_lim_t *, uint32_t *);
129 	void (*lmtemp_setlim)(struct sysmon_envsys *, envsys_data_t *,
130 		sysmon_envsys_lim_t *, uint32_t *);
131 } lmtemptbl[] = {
132 [lmtemp_lm75] =
133 	{
134 		.lmtemp_name = "LM75",
135 		.lmtemp_addrmask = LM75_ADDRMASK,
136 		.lmtemp_addr = LM75_ADDR,
137 		.lmtemp_decode = lmtemp_decode_lm75,
138 		.lmtemp_encode = lmtemp_encode_lm75,
139 		.lmtemp_getlim = lmtemp_getlim_lm75,
140 		.lmtemp_setlim = lmtemp_setlim_lm75,
141 	},
142 [lmtemp_ds75] =
143 	{
144 		.lmtemp_name = "DS75",
145 		.lmtemp_addrmask = LM75_ADDRMASK,
146 		.lmtemp_addr = LM75_ADDR,
147 		.lmtemp_decode = lmtemp_decode_ds75,
148 		.lmtemp_encode = lmtemp_encode_ds75,
149 		.lmtemp_getlim = lmtemp_getlim_lm75,
150 		.lmtemp_setlim = lmtemp_setlim_lm75,
151 	},
152 [lmtemp_lm77] =
153 	{
154 		.lmtemp_name = "LM77",
155 		.lmtemp_addrmask = LM77_ADDRMASK,
156 		.lmtemp_addr = LM77_ADDR,
157 		.lmtemp_decode = lmtemp_decode_lm77,
158 		.lmtemp_encode = lmtemp_encode_lm77,
159 		.lmtemp_getlim = lmtemp_getlim_lm77,
160 		.lmtemp_setlim = lmtemp_setlim_lm77,
161 	},
162 };
163 
164 static int
165 lmtemp_match(device_t parent, cfdata_t cf, void *aux)
166 {
167 	struct i2c_attach_args *ia = aux;
168 	int i, match_result;
169 
170 	if (iic_use_direct_match(ia, cf, compat_data, &match_result))
171 		return match_result;
172 
173 	/*
174 	 * Indirect config - not much we can do!
175 	 */
176 	for (i = 0; i < __arraycount(lmtemptbl); i++) {
177 		if (i == cf->cf_flags) {
178 			break;
179 		}
180 	}
181 	if (i == __arraycount(lmtemptbl)) {
182 		return 0;
183 	}
184 
185 	if ((ia->ia_addr & lmtemptbl[i].lmtemp_addrmask) ==
186 	    lmtemptbl[i].lmtemp_addr)
187 		return I2C_MATCH_ADDRESS_ONLY;
188 
189 	return 0;
190 }
191 
192 static void
193 lmtemp_attach(device_t parent, device_t self, void *aux)
194 {
195 	struct lmtemp_softc *sc = device_private(self);
196 	struct i2c_attach_args *ia = aux;
197 	const struct device_compatible_entry *dce;
198 	char name[64];
199 	const char *desc;
200 	int i;
201 
202 	sc->sc_dev = self;
203 	dce = iic_compatible_lookup(ia, compat_data);
204 	if (dce != NULL) {
205 		i = (int)dce->value;
206 	} else {
207 		for (i = 0; i < __arraycount(lmtemptbl); i++) {
208 			if (i == device_cfdata(self)->cf_flags) {
209 				break;
210 			}
211 		}
212 		KASSERT(i < __arraycount(lmtemptbl));
213 	}
214 
215 	sc->sc_tag = ia->ia_tag;
216 	sc->sc_address = ia->ia_addr;
217 	sc->sc_prop = ia->ia_prop;
218 	prop_object_retain(sc->sc_prop);
219 
220 	aprint_naive(": Temperature Sensor\n");
221 	if (ia->ia_name) {
222 		aprint_normal(": %s %s Temperature Sensor\n", ia->ia_name,
223 			lmtemptbl[i].lmtemp_name);
224 	} else {
225 		aprint_normal(": %s Temperature Sensor\n",
226 			lmtemptbl[i].lmtemp_name);
227 	}
228 
229 	sc->sc_lmtemp_decode = lmtemptbl[i].lmtemp_decode;
230 	sc->sc_lmtemp_encode = lmtemptbl[i].lmtemp_encode;
231 
232 	iic_acquire_bus(sc->sc_tag, 0);
233 
234 	/* Read temperature limit(s) and remember initial value(s). */
235 	if (i == lmtemp_lm77) {
236 		if (lmtemp_temp_read(sc, LM77_REG_TCRIT_SET_POINT,
237 		    &sc->sc_scrit, 1) != 0) {
238 			aprint_error_dev(self,
239 			    "unable to read low register\n");
240 			iic_release_bus(sc->sc_tag, 0);
241 			return;
242 		}
243 		if (lmtemp_temp_read(sc, LM77_REG_TLOW_SET_POINT,
244 		    &sc->sc_smin, 1) != 0) {
245 			aprint_error_dev(self,
246 			    "unable to read low register\n");
247 			iic_release_bus(sc->sc_tag, 0);
248 			return;
249 		}
250 		if (lmtemp_temp_read(sc, LM77_REG_THIGH_SET_POINT,
251 		    &sc->sc_smax, 1) != 0) {
252 			aprint_error_dev(self,
253 			    "unable to read high register\n");
254 			iic_release_bus(sc->sc_tag, 0);
255 			return;
256 		}
257 	} else {	/* LM75 or compatible */
258 		if (lmtemp_temp_read(sc, LM75_REG_TOS_SET_POINT,
259 		    &sc->sc_smax, 1) != 0) {
260 			aprint_error_dev(self, "unable to read Tos register\n");
261 			iic_release_bus(sc->sc_tag, 0);
262 			return;
263 		}
264 	}
265 	sc->sc_tmax = sc->sc_smax;
266 
267 	if (i == lmtemp_lm75)
268 		lmtemp_setup_sysctl(sc);
269 
270 	/* Set the configuration of the LM75 to defaults. */
271 	if (lmtemp_config_write(sc, LM75_CONFIG_FAULT_QUEUE_4) != 0) {
272 		aprint_error_dev(self, "unable to write config register\n");
273 		iic_release_bus(sc->sc_tag, 0);
274 		return;
275 	}
276 	iic_release_bus(sc->sc_tag, 0);
277 
278 	sc->sc_sme = sysmon_envsys_create();
279 	/* Initialize sensor data. */
280 	sc->sc_sensor.units =  ENVSYS_STEMP;
281 	sc->sc_sensor.state =  ENVSYS_SINVALID;
282 	sc->sc_sensor.flags =  ENVSYS_FMONLIMITS | ENVSYS_FHAS_ENTROPY;
283 
284 	(void)strlcpy(name,
285 	    ia->ia_name? ia->ia_name : device_xname(self),
286 	    sizeof(sc->sc_sensor.desc));
287 
288 	if (prop_dictionary_get_cstring_nocopy(sc->sc_prop, "s00", &desc)) {
289 		strncpy(name, desc, 64);
290 	}
291 
292 	(void)strlcpy(sc->sc_sensor.desc, name,
293 	    sizeof(sc->sc_sensor.desc));
294 	if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
295 		sysmon_envsys_destroy(sc->sc_sme);
296 		return;
297 	}
298 
299 	/* Hook into system monitor. */
300 	sc->sc_sme->sme_name = device_xname(self);
301 	sc->sc_sme->sme_cookie = sc;
302 	sc->sc_sme->sme_refresh = lmtemp_refresh;
303 	sc->sc_sme->sme_get_limits = lmtemptbl[i].lmtemp_getlim;
304 	sc->sc_sme->sme_set_limits = lmtemptbl[i].lmtemp_setlim;
305 
306 	if (sysmon_envsys_register(sc->sc_sme)) {
307 		aprint_error_dev(self, "unable to register with sysmon\n");
308 		sysmon_envsys_destroy(sc->sc_sme);
309 	}
310 }
311 
312 static int
313 lmtemp_config_write(struct lmtemp_softc *sc, uint8_t val)
314 {
315 	uint8_t cmdbuf[2];
316 
317 	cmdbuf[0] = LM75_REG_CONFIG;
318 	cmdbuf[1] = val;
319 
320 	return iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
321 	    sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0);
322 }
323 
324 static int
325 lmtemp_temp_write(struct lmtemp_softc *sc, uint8_t reg, uint32_t val, int degc)
326 {
327 	uint8_t cmdbuf[3];
328 
329 	cmdbuf[0] = reg;
330 	sc->sc_lmtemp_encode(val, &cmdbuf[1], degc);
331 
332 	return iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
333 	    sc->sc_address, cmdbuf, 1, &cmdbuf[1], 2, 0);
334 }
335 
336 static int
337 lmtemp_temp_read(struct lmtemp_softc *sc, uint8_t which, uint32_t *valp,
338     int degc)
339 {
340 	int error;
341 	uint8_t cmdbuf[1];
342 	uint8_t buf[LM75_TEMP_LEN];
343 
344 	cmdbuf[0] = which;
345 
346 	error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
347 	    sc->sc_address, cmdbuf, 1, buf, LM75_TEMP_LEN, 0);
348 	if (error)
349 		return error;
350 
351 	*valp = sc->sc_lmtemp_decode(buf, degc);
352 	return 0;
353 }
354 
355 static void
356 lmtemp_refresh_sensor_data(struct lmtemp_softc *sc)
357 {
358 	uint32_t val;
359 	int error;
360 
361 	error = lmtemp_temp_read(sc, LM75_REG_TEMP, &val, 0);
362 	if (error) {
363 #if 0
364 		aprint_error_dev(sc->sc_dev, "unable to read temperature, error = %d\n",
365 		    error);
366 #endif
367 		sc->sc_sensor.state = ENVSYS_SINVALID;
368 		return;
369 	}
370 
371 	sc->sc_sensor.value_cur = val;
372 	sc->sc_sensor.state = ENVSYS_SVALID;
373 }
374 
375 static void
376 lmtemp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
377 {
378 	struct lmtemp_softc *sc = sme->sme_cookie;
379 
380 	iic_acquire_bus(sc->sc_tag, 0);	/* also locks our instance */
381 	lmtemp_refresh_sensor_data(sc);
382 	iic_release_bus(sc->sc_tag, 0);	/* also unlocks our instance */
383 }
384 
385 static void
386 lmtemp_getlim_lm75(struct sysmon_envsys *sme, envsys_data_t *edata,
387     sysmon_envsys_lim_t *limits, uint32_t *props)
388 {
389 	struct lmtemp_softc *sc = sme->sme_cookie;
390 	uint32_t val;
391 
392 	*props &= ~(PROP_CRITMAX);
393 
394 	iic_acquire_bus(sc->sc_tag, 0);
395 	if (lmtemp_temp_read(sc, LM75_REG_TOS_SET_POINT, &val, 0) == 0) {
396 		limits->sel_critmax = val;
397 		*props |= PROP_CRITMAX;
398 	}
399 	iic_release_bus(sc->sc_tag, 0);
400 }
401 
402 static void
403 lmtemp_getlim_lm77(struct sysmon_envsys *sme, envsys_data_t *edata,
404     sysmon_envsys_lim_t *limits, uint32_t *props)
405 {
406 	struct lmtemp_softc *sc = sme->sme_cookie;
407 	uint32_t val;
408 
409 	*props &= ~(PROP_CRITMAX | PROP_WARNMAX | PROP_WARNMIN);
410 
411 	iic_acquire_bus(sc->sc_tag, 0);
412 	if (lmtemp_temp_read(sc, LM77_REG_TCRIT_SET_POINT, &val, 0) == 0) {
413 		limits->sel_critmax = val;
414 		*props |= PROP_CRITMAX;
415 	}
416 	if (lmtemp_temp_read(sc, LM77_REG_THIGH_SET_POINT, &val, 0) == 0) {
417 		limits->sel_warnmax = val;
418 		*props |= PROP_WARNMAX;
419 	}
420 	if (lmtemp_temp_read(sc, LM77_REG_TLOW_SET_POINT, &val, 0) == 0) {
421 		limits->sel_warnmin = val;
422 		*props |= PROP_WARNMIN;
423 	}
424 	iic_release_bus(sc->sc_tag, 0);
425 }
426 
427 static void
428 lmtemp_setlim_lm75(struct sysmon_envsys *sme, envsys_data_t *edata,
429     sysmon_envsys_lim_t *limits, uint32_t *props)
430 {
431 	struct lmtemp_softc *sc = sme->sme_cookie;
432 	int32_t limit;
433 
434 	if (*props & PROP_CRITMAX) {
435 		if (limits == NULL)	/* Restore defaults */
436 			limit = sc->sc_smax;
437 		else
438 			limit = limits->sel_critmax;
439 		iic_acquire_bus(sc->sc_tag, 0);
440 		lmtemp_temp_write(sc, LM75_REG_THYST_SET_POINT,
441 		    limit - 5000000, 0);
442 		lmtemp_temp_write(sc, LM75_REG_TOS_SET_POINT, limit, 0);
443 		iic_release_bus(sc->sc_tag, 0);
444 
445 		/* Synchronise sysctl */
446 		sc->sc_tmax = (limit - 273150000) / 1000000;
447 	}
448 }
449 
450 static void
451 lmtemp_setlim_lm77(struct sysmon_envsys *sme, envsys_data_t *edata,
452     sysmon_envsys_lim_t *limits, uint32_t *props)
453 {
454 	struct lmtemp_softc *sc = sme->sme_cookie;
455 	int32_t limit;
456 
457 	iic_acquire_bus(sc->sc_tag, 0);
458 	if (*props & PROP_CRITMAX) {
459 		if (limits == NULL)	/* Restore defaults */
460 			limit = sc->sc_scrit;
461 		else
462 			limit = limits->sel_critmax;
463 		lmtemp_temp_write(sc, LM77_REG_TCRIT_SET_POINT, limit, 0);
464 	}
465 	if (*props & PROP_WARNMAX) {
466 		if (limits == NULL)	/* Restore defaults */
467 			limit = sc->sc_smax;
468 		else
469 			limit = limits->sel_warnmax;
470 		lmtemp_temp_write(sc, LM77_REG_THIGH_SET_POINT, limit, 0);
471 	}
472 	if (*props & PROP_WARNMIN) {
473 		if (limits == NULL)	/* Restore defaults */
474 			limit = sc->sc_smin;
475 		else
476 			limit = limits->sel_warnmin;
477 		lmtemp_temp_write(sc, LM77_REG_TLOW_SET_POINT, limit, 0);
478 	}
479 	iic_release_bus(sc->sc_tag, 0);
480 }
481 
482 static uint32_t
483 lmtemp_decode_lm75(const uint8_t *buf, int degc)
484 {
485 	int temp;
486 	uint32_t val;
487 
488 	/*
489 	 * LM75 temps are the most-significant 9 bits of a 16-bit reg.
490 	 * sign-extend the MSB and add in the 0.5 from the LSB
491 	 */
492 	temp = (int8_t) buf[0];
493 	temp = (temp << 1) + ((buf[1] >> 7) & 0x1);
494 
495 	/* Temp is given in 1/2 deg. C, we convert to C or uK. */
496 	if (degc)
497 		val = temp / 2;
498 	else
499 		val = temp * 500000 + 273150000;
500 
501 	return val;
502 }
503 
504 static uint32_t
505 lmtemp_decode_ds75(const uint8_t *buf, int degc)
506 {
507 	int temp;
508 
509 	/*
510 	 * Sign-extend the MSB byte, and add in the fractions of a
511 	 * degree contained in the LSB (precision 1/16th DegC).
512 	 */
513 	temp = (int8_t)buf[0];
514 	temp = (temp << 4) | ((buf[1] >> 4) & 0xf);
515 
516 	/*
517 	 * Conversion to C or uK is simple.
518 	 */
519 	if (degc)
520 		return temp / 16;
521 	else
522 		return (temp * 62500 + 273150000);
523 }
524 
525 static uint32_t
526 lmtemp_decode_lm77(const uint8_t *buf, int degc)
527 {
528 	int temp;
529 	uint32_t val;
530 
531 	/*
532 	 * Describe each bits of temperature registers on LM77.
533 	 *   D15 - D12:	Sign
534 	 *   D11 - D3 :	Bit8(MSB) - Bit0
535 	 */
536 	temp = (int8_t)buf[0];
537 	temp = (temp << 5) | ((buf[1] >> 3) & 0x1f);
538 
539 	/* Temp is given in 1/2 deg. C, we convert to C or uK. */
540 	if (degc)
541 		val = temp / 2;
542 	else
543 		val = temp * 500000 + 273150000;
544 
545 	return val;
546 }
547 
548 static void lmtemp_encode_lm75(const uint32_t val, uint8_t *buf, int degc)
549 {
550 	int temp;
551 
552 	/* Convert from C or uK to register format */
553 	if (degc)
554 		temp = val * 2;
555 	else
556 		temp = (val - 273150000) / 500000;
557 	buf[0] = (temp >> 1) & 0xff;
558 	buf[1] = (temp & 1) << 7;
559 }
560 
561 static void lmtemp_encode_ds75(const uint32_t val, uint8_t *buf, int degc)
562 {
563 	int temp;
564 
565 	/* Convert from C or uK to register format */
566 	if (degc)
567 		temp = val * 16;
568 	else
569 		temp = (val - 273150000) / 62500;
570 	buf[0] = (temp >> 4) & 0xff;
571 	buf[1] = (temp & 0xf) << 4;
572 }
573 
574 static void lmtemp_encode_lm77(const uint32_t val, uint8_t *buf, int degc)
575 {
576 	int temp;
577 
578 	/* Convert from C or uK to register format */
579 	if (degc)
580 		temp = val * 2;
581 	else
582 		temp = (val - 273150000) / 500000;
583 	buf[0] = (temp >> 5) & 0xff;
584 	buf[1] = (temp & 0x1f) << 3;
585 }
586 
587 static void
588 lmtemp_setup_sysctl(struct lmtemp_softc *sc)
589 {
590 	const struct sysctlnode *me = NULL, *node = NULL;
591 
592 	sysctl_createv(NULL, 0, NULL, &me,
593 	    CTLFLAG_READWRITE,
594 	    CTLTYPE_NODE, device_xname(sc->sc_dev), NULL,
595 	    NULL, 0, NULL, 0,
596 	    CTL_MACHDEP, CTL_CREATE, CTL_EOL);
597 
598 	sysctl_createv(NULL, 0, NULL, &node,
599 	    CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
600 	    CTLTYPE_INT, "temp", "Threshold temperature",
601 	    sysctl_lm75_temp, 1, (void *)sc, 0,
602 	    CTL_MACHDEP, me->sysctl_num, CTL_CREATE, CTL_EOL);
603 }
604 
605 static int
606 sysctl_lm75_temp(SYSCTLFN_ARGS)
607 {
608 	struct sysctlnode node = *rnode;
609 	struct lmtemp_softc *sc = node.sysctl_data;
610 	int temp;
611 
612 	if (newp) {
613 
614 		/* we're asked to write */
615 		node.sysctl_data = &sc->sc_tmax;
616 		if (sysctl_lookup(SYSCTLFN_CALL(&node)) == 0) {
617 
618 			temp = *(int *)node.sysctl_data;
619 			sc->sc_tmax = temp;
620 			iic_acquire_bus(sc->sc_tag, 0);
621 			lmtemp_temp_write(sc, LM75_REG_THYST_SET_POINT,
622 			    sc->sc_tmax - 5, 1);
623 			lmtemp_temp_write(sc, LM75_REG_TOS_SET_POINT,
624 			    sc->sc_tmax, 1);
625 			iic_release_bus(sc->sc_tag, 0);
626 
627 			/* Synchronise envsys - calls lmtemp_getlim_lm75() */
628 			sysmon_envsys_update_limits(sc->sc_sme, &sc->sc_sensor);
629 			return 0;
630 		}
631 		return EINVAL;
632 	} else {
633 
634 		node.sysctl_data = &sc->sc_tmax;
635 		node.sysctl_size = 4;
636 		return (sysctl_lookup(SYSCTLFN_CALL(&node)));
637 	}
638 
639 	return 0;
640 }
641 
642 SYSCTL_SETUP(sysctl_lmtemp_setup, "sysctl lmtemp subtree setup")
643 {
644 
645 	sysctl_createv(NULL, 0, NULL, NULL,
646 		       CTLFLAG_PERMANENT,
647 		       CTLTYPE_NODE, "machdep", NULL,
648 		       NULL, 0, NULL, 0,
649 		       CTL_MACHDEP, CTL_EOL);
650 }
651 
652 
653