1 /* $NetBSD: em3027.c,v 1.8 2021/01/27 02:29:48 thorpej Exp $ */
2 /*
3 * Copyright (c) 2018 Valery Ushakov
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /*
28 * EM Microelectronic EM3027 RTC
29 */
30 #include <sys/cdefs.h>
31 __KERNEL_RCSID(0, "$NetBSD: em3027.c,v 1.8 2021/01/27 02:29:48 thorpej Exp $");
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/device.h>
36 #include <sys/kernel.h>
37
38 #include <dev/clock_subr.h>
39
40 #include <dev/i2c/i2cvar.h>
41 #include <dev/i2c/em3027reg.h>
42 #include <dev/sysmon/sysmonvar.h>
43
44 #if 0
45 #define aprint_verbose_dev aprint_normal_dev
46 #define aprint_debug_dev aprint_normal_dev
47 #endif
48
49
50 struct em3027rtc_softc {
51 device_t sc_dev;
52
53 i2c_tag_t sc_tag;
54 i2c_addr_t sc_addr;
55
56 bool sc_vlow;
57
58 struct todr_chip_handle sc_todr;
59
60 struct sysmon_envsys *sc_sme;
61 envsys_data_t sc_sensor;
62 };
63
64
65 #define EM3027_CONTROL_BASE EM3027_ONOFF
66 #define EM3027_WATCH_BASE EM3027_WATCH_SEC
67
68 struct em3027rtc_watch {
69 uint8_t sec;
70 uint8_t min;
71 uint8_t hour;
72 uint8_t day;
73 uint8_t wday;
74 uint8_t mon;
75 uint8_t year;
76 };
77
78 #define EM3027_WATCH_SIZE (EM3027_WATCH_YEAR - EM3027_WATCH_BASE + 1)
79 __CTASSERT(sizeof(struct em3027rtc_watch) == EM3027_WATCH_SIZE);
80
81 #define EM3027_BASE_YEAR 1980
82
83
84 static int em3027rtc_match(device_t, cfdata_t, void *);
85 static void em3027rtc_attach(device_t, device_t, void *);
86
87 CFATTACH_DECL_NEW(em3027rtc, sizeof(struct em3027rtc_softc),
88 em3027rtc_match, em3027rtc_attach, NULL, NULL);
89
90
91 static bool em3027rtc_enable_thermometer(struct em3027rtc_softc *);
92 static void em3027rtc_envsys_attach(struct em3027rtc_softc *);
93
94 static int em3027rtc_gettime(struct todr_chip_handle *, struct clock_ymdhms *);
95 static int em3027rtc_settime(struct todr_chip_handle *, struct clock_ymdhms *);
96
97 static void em3027rtc_sme_refresh(struct sysmon_envsys *, envsys_data_t *);
98
99 static int em3027rtc_iic_exec(struct em3027rtc_softc *, i2c_op_t, uint8_t,
100 void *, size_t);
101
102 static int em3027rtc_read(struct em3027rtc_softc *, uint8_t, void *, size_t);
103 static int em3027rtc_write(struct em3027rtc_softc *, uint8_t, void *, size_t);
104
105 static int em3027rtc_read_byte(struct em3027rtc_softc *, uint8_t, uint8_t *);
106 static int em3027rtc_write_byte(struct em3027rtc_softc *, uint8_t, uint8_t);
107
108 static const struct device_compatible_entry compat_data[] = {
109 { .compat = "emmicro,em3027" },
110 DEVICE_COMPAT_EOL
111 };
112
113 static int
em3027rtc_match(device_t parent,cfdata_t cf,void * aux)114 em3027rtc_match(device_t parent, cfdata_t cf, void *aux)
115 {
116 const struct i2c_attach_args *ia = aux;
117 uint8_t reg;
118 int error;
119 int match_result;
120
121 if (iic_use_direct_match(ia, cf, compat_data, &match_result))
122 return match_result;
123
124 if (ia->ia_addr != EM3027_ADDR)
125 return 0;
126
127 /* check if the device is there */
128 error = iic_acquire_bus(ia->ia_tag, 0);
129 if (error)
130 return 0;
131
132 error = iic_smbus_read_byte(ia->ia_tag, ia->ia_addr,
133 EM3027_ONOFF, ®, 0);
134 iic_release_bus(ia->ia_tag, 0);
135 if (error)
136 return 0;
137
138 return I2C_MATCH_ADDRESS_AND_PROBE;
139 }
140
141
142 static void
em3027rtc_attach(device_t parent,device_t self,void * aux)143 em3027rtc_attach(device_t parent, device_t self, void *aux)
144 {
145 struct em3027rtc_softc *sc = device_private(self);
146 const struct i2c_attach_args *ia = aux;
147 struct ctl {
148 uint8_t onoff;
149 uint8_t irq_ctl;
150 uint8_t irq_flags;
151 uint8_t status;
152 } ctl;
153 int error;
154
155 aprint_naive(": Real-time Clock and Temperature Sensor\n");
156 aprint_normal(": Real-time Clock and Temperature Sensor\n");
157
158 sc->sc_dev = self;
159
160 sc->sc_tag = ia->ia_tag;
161 sc->sc_addr = ia->ia_addr;
162
163
164 /*
165 * Control Page registers
166 */
167 error = em3027rtc_read(sc, EM3027_CONTROL_BASE, &ctl, sizeof(ctl));
168 if (error) {
169 aprint_error_dev(sc->sc_dev,
170 "failed to read control page (error %d)\n", error);
171 return;
172 }
173
174
175 /* Status */
176 aprint_debug_dev(sc->sc_dev, "status=0x%02x\n", ctl.status);
177
178 /* Complain about low voltage but continue anyway */
179 if (ctl.status & EM3027_STATUS_VLOW2) {
180 aprint_error_dev(sc->sc_dev, "voltage low (VLow2)\n");
181 sc->sc_vlow = true;
182 }
183 else if (ctl.status & EM3027_STATUS_VLOW1) {
184 aprint_error_dev(sc->sc_dev, "voltage low (VLow1)\n");
185 sc->sc_vlow = true;
186 }
187
188 ctl.status = EM3027_STATUS_POWER_ON;
189
190
191 /* On/Off */
192 aprint_debug_dev(sc->sc_dev, "on/off=0x%02x\n", ctl.onoff);
193
194 if ((ctl.onoff & EM3027_ONOFF_SR) == 0) {
195 aprint_verbose_dev(sc->sc_dev, "enabling self-recovery\n");
196 ctl.onoff |= EM3027_ONOFF_SR;
197 }
198
199 if ((ctl.onoff & EM3027_ONOFF_EEREF) == 0) {
200 aprint_verbose_dev(sc->sc_dev, "enabling EEPROM self-refresh\n");
201 ctl.onoff |= EM3027_ONOFF_EEREF;
202 }
203
204 ctl.onoff &= ~EM3027_ONOFF_TR;
205
206 if (ctl.onoff & EM3027_ONOFF_TI) {
207 aprint_verbose_dev(sc->sc_dev, "disabling timer\n");
208 ctl.onoff &= ~EM3027_ONOFF_TI;
209 }
210
211 if ((ctl.onoff & EM3027_ONOFF_WA) == 0) {
212 aprint_verbose_dev(sc->sc_dev, "enabling watch\n");
213 ctl.onoff |= EM3027_ONOFF_WA;
214 }
215
216
217 /* IRQ Control/Flags */
218 if (ctl.irq_ctl != 0)
219 aprint_debug_dev(sc->sc_dev,
220 "irq=0x%02x - disabling all\n", ctl.irq_ctl);
221 ctl.irq_ctl = 0;
222 ctl.irq_flags = 0;
223
224
225 /* Write them back */
226 error = em3027rtc_write(sc, EM3027_CONTROL_BASE, &ctl, sizeof(ctl));
227 if (error) {
228 aprint_error_dev(sc->sc_dev,
229 "failed to write control page (error %d)\n", error);
230 return;
231 }
232
233
234 /*
235 * Attach RTC
236 */
237 sc->sc_todr.cookie = sc;
238 sc->sc_todr.todr_gettime_ymdhms = em3027rtc_gettime;
239 sc->sc_todr.todr_settime_ymdhms = em3027rtc_settime;
240 sc->sc_todr.todr_setwen = NULL;
241
242 todr_attach(&sc->sc_todr);
243
244
245 /*
246 * Attach thermometer
247 */
248 em3027rtc_envsys_attach(sc);
249 }
250
251
252 static bool
em3027rtc_enable_thermometer(struct em3027rtc_softc * sc)253 em3027rtc_enable_thermometer(struct em3027rtc_softc *sc)
254 {
255 uint8_t eeprom_ctl;
256 int error;
257
258 error = em3027rtc_read_byte(sc, EM3027_EEPROM_CTL, &eeprom_ctl);
259 if (error) {
260 aprint_error_dev(sc->sc_dev,
261 "failed to read eeprom control (error %d)\n", error);
262 return false;
263 }
264
265 aprint_debug_dev(sc->sc_dev, "eeprom ctl=0x%02x\n", eeprom_ctl);
266 if (eeprom_ctl & EM3027_EEPROM_THERM_ENABLE)
267 return true;
268
269 eeprom_ctl |= EM3027_EEPROM_THERM_ENABLE;
270 error = em3027rtc_write_byte(sc, EM3027_EEPROM_CTL, eeprom_ctl);
271 if (error) {
272 aprint_error_dev(sc->sc_dev,
273 "failed to write eeprom control (error %d)\n", error);
274 return false;
275 }
276
277 return true;
278 }
279
280
281 static void
em3027rtc_envsys_attach(struct em3027rtc_softc * sc)282 em3027rtc_envsys_attach(struct em3027rtc_softc *sc)
283 {
284 int error;
285
286 if (!em3027rtc_enable_thermometer(sc)) {
287 aprint_error_dev(sc->sc_dev, "thermometer not enabled\n");
288 return;
289 }
290
291 sc->sc_sme = sysmon_envsys_create();
292
293 sc->sc_sme->sme_name = device_xname(sc->sc_dev);
294 sc->sc_sme->sme_cookie = sc;
295 sc->sc_sme->sme_refresh = em3027rtc_sme_refresh;
296
297 sc->sc_sensor.units = ENVSYS_STEMP;
298 sc->sc_sensor.state = ENVSYS_SINVALID;
299 sc->sc_sensor.flags = 0;
300 strlcpy(sc->sc_sensor.desc, "temperature", sizeof(sc->sc_sensor.desc));
301
302 error = sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor);
303 if (error) {
304 aprint_error_dev(sc->sc_dev,
305 "unable to attach sensor (error %d)\n", error);
306 goto out;
307 }
308
309 error = sysmon_envsys_register(sc->sc_sme);
310 if (error) {
311 aprint_error_dev(sc->sc_dev,
312 "unable to register with sysmon (error %d)\n", error);
313 goto out;
314 }
315
316 return;
317
318 out:
319 if (error) {
320 sysmon_envsys_destroy(sc->sc_sme);
321 sc->sc_sme = NULL;
322 }
323 }
324
325
326 static int
em3027rtc_iic_exec(struct em3027rtc_softc * sc,i2c_op_t op,uint8_t reg,void * buf,size_t len)327 em3027rtc_iic_exec(struct em3027rtc_softc *sc, i2c_op_t op, uint8_t reg,
328 void *buf, size_t len)
329 {
330 const int flags = 0;
331 int error;
332
333 error = iic_acquire_bus(sc->sc_tag, flags);
334 if (error)
335 return error;
336
337 error = iic_exec(sc->sc_tag, op, sc->sc_addr,
338 ®, 1,
339 (uint8_t *)buf, len,
340 flags);
341
342 /* XXX: horrible hack that seems to be needed on utilite */
343 if (reg == EM3027_WATCH_BASE)
344 DELAY(1);
345
346 iic_release_bus(sc->sc_tag, flags);
347 return error;
348 }
349
350
351 static int
em3027rtc_read(struct em3027rtc_softc * sc,uint8_t reg,void * buf,size_t len)352 em3027rtc_read(struct em3027rtc_softc *sc, uint8_t reg, void *buf, size_t len)
353 {
354
355 return em3027rtc_iic_exec(sc, I2C_OP_READ_WITH_STOP, reg, buf, len);
356 }
357
358
359 static int
em3027rtc_read_byte(struct em3027rtc_softc * sc,uint8_t reg,uint8_t * valp)360 em3027rtc_read_byte(struct em3027rtc_softc *sc, uint8_t reg, uint8_t *valp)
361 {
362
363 return em3027rtc_read(sc, reg, valp, 1);
364 }
365
366
367 static int
em3027rtc_write(struct em3027rtc_softc * sc,uint8_t reg,void * buf,size_t len)368 em3027rtc_write(struct em3027rtc_softc *sc, uint8_t reg, void *buf, size_t len)
369 {
370
371 return em3027rtc_iic_exec(sc, I2C_OP_WRITE_WITH_STOP, reg, buf, len);
372 }
373
374
375 static int
em3027rtc_write_byte(struct em3027rtc_softc * sc,uint8_t reg,uint8_t val)376 em3027rtc_write_byte(struct em3027rtc_softc *sc, uint8_t reg, uint8_t val)
377 {
378
379 return em3027rtc_write(sc, reg, &val, 1);
380 }
381
382
383 static int
em3027rtc_gettime(struct todr_chip_handle * todr,struct clock_ymdhms * dt)384 em3027rtc_gettime(struct todr_chip_handle *todr, struct clock_ymdhms *dt)
385 {
386 struct em3027rtc_softc *sc = todr->cookie;
387 struct em3027rtc_watch w;
388 int error;
389
390 error = em3027rtc_read(sc, EM3027_WATCH_BASE, &w, sizeof(w));
391 if (error) {
392 aprint_error_dev(sc->sc_dev,
393 "failed to read watch (error %d)\n", error);
394 return error;
395 }
396
397 dt->dt_sec = bcdtobin(w.sec);
398 dt->dt_min = bcdtobin(w.min);
399
400 if (w.hour & EM3027_WATCH_HOUR_S12) {
401 const int pm = w.hour & EM3027_WATCH_HOUR_PM;
402 int hr;
403
404 w.hour &= ~(EM3027_WATCH_HOUR_S12 | EM3027_WATCH_HOUR_PM);
405 hr = bcdtobin(w.hour);
406 if (hr == 12)
407 hr = pm ? 12 : 0;
408 else if (pm)
409 hr += 12;
410
411 dt->dt_hour = hr;
412 }
413 else {
414 dt->dt_hour = bcdtobin(w.hour);
415 }
416
417 dt->dt_day = bcdtobin(w.day);
418 dt->dt_wday = bcdtobin(w.wday) - 1;
419 dt->dt_mon = bcdtobin(w.mon);
420 dt->dt_year = bcdtobin(w.year) + EM3027_BASE_YEAR;
421
422 return 0;
423 }
424
425
426 static int
em3027rtc_settime(struct todr_chip_handle * todr,struct clock_ymdhms * dt)427 em3027rtc_settime(struct todr_chip_handle *todr, struct clock_ymdhms *dt)
428 {
429 struct em3027rtc_softc *sc = todr->cookie;
430 struct em3027rtc_watch w;
431 int error;
432
433 w.sec = bintobcd(dt->dt_sec);
434 w.min = bintobcd(dt->dt_min);
435 w.hour = bintobcd(dt->dt_hour);
436 w.day = bintobcd(dt->dt_day);
437 w.wday = bintobcd(dt->dt_wday + 1);
438 w.mon = bintobcd(dt->dt_mon);
439 w.year = bintobcd(dt->dt_year - EM3027_BASE_YEAR);
440
441 error = em3027rtc_write(sc, EM3027_WATCH_BASE, &w, sizeof(w));
442 return error;
443 }
444
445
446 static void
em3027rtc_sme_refresh(struct sysmon_envsys * sme,envsys_data_t * edata)447 em3027rtc_sme_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
448 {
449 struct em3027rtc_softc *sc = sme->sme_cookie;
450 uint8_t status, t_raw;
451 uint32_t t_uk;
452 int error;
453
454 edata->state = ENVSYS_SINVALID;
455
456 error = em3027rtc_read_byte(sc, EM3027_STATUS, &status);
457 if (error) {
458 aprint_debug_dev(sc->sc_dev,
459 "failed to read status (error %d)\n", error);
460 return;
461 }
462
463 if (status & (EM3027_STATUS_VLOW2 | EM3027_STATUS_VLOW1)) {
464 if (!sc->sc_vlow) {
465 sc->sc_vlow = true;
466 aprint_error_dev(sc->sc_dev,
467 "voltage low, thermometer is disabled\n");
468 }
469 return;
470 }
471 else
472 sc->sc_vlow = false;
473
474 error = em3027rtc_read_byte(sc, EM3027_TEMP, &t_raw);
475 if (error) {
476 aprint_debug_dev(sc->sc_dev,
477 "failed to read temperature (error %d)\n", error);
478 return;
479 }
480
481
482 /* convert to microkelvin */
483 t_uk = ((int)t_raw + EM3027_TEMP_BASE) * 1000000 + 273150000;
484
485 edata->value_cur = t_uk;
486 edata->state = ENVSYS_SVALID;
487 }
488