1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * RTC driver for the MAX31335
4 *
5 * Copyright (C) 2023 Analog Devices
6 *
7 * Antoniu Miclaus <antoniu.miclaus@analog.com>
8 *
9 */
10
11 #include <linux/unaligned.h>
12 #include <linux/bcd.h>
13 #include <linux/bitfield.h>
14 #include <linux/bitops.h>
15 #include <linux/clk.h>
16 #include <linux/clk-provider.h>
17 #include <linux/hwmon.h>
18 #include <linux/i2c.h>
19 #include <linux/interrupt.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/of_device.h>
23 #include <linux/regmap.h>
24 #include <linux/rtc.h>
25 #include <linux/util_macros.h>
26
27 /* MAX31335 Register Map */
28 #define MAX31335_STATUS1 0x00
29 #define MAX31335_INT_EN1 0x01
30 #define MAX31335_STATUS2 0x02
31 #define MAX31335_INT_EN2 0x03
32 #define MAX31335_RTC_RESET 0x04
33 #define MAX31335_RTC_CONFIG 0x05
34 #define MAX31335_RTC_CONFIG2 0x06
35 #define MAX31335_TIMESTAMP_CONFIG 0x07
36 #define MAX31335_TIMER_CONFIG 0x08
37 #define MAX31335_SECONDS_1_128 0x09
38 #define MAX31335_SECONDS 0x0A
39 #define MAX31335_MINUTES 0x0B
40 #define MAX31335_HOURS 0x0C
41 #define MAX31335_DAY 0x0D
42 #define MAX31335_DATE 0x0E
43 #define MAX31335_MONTH 0x0F
44 #define MAX31335_YEAR 0x0F
45 #define MAX31335_ALM1_SEC 0x11
46 #define MAX31335_ALM1_MIN 0x12
47 #define MAX31335_ALM1_HRS 0x13
48 #define MAX31335_ALM1_DAY_DATE 0x14
49 #define MAX31335_ALM1_MON 0x15
50 #define MAX31335_ALM1_YEAR 0x16
51 #define MAX31335_ALM2_MIN 0x17
52 #define MAX31335_ALM2_HRS 0x18
53 #define MAX31335_ALM2_DAY_DATE 0x19
54 #define MAX31335_TIMER_COUNT 0x1A
55 #define MAX31335_TIMER_INIT 0x1B
56 #define MAX31335_PWR_MGMT 0x1C
57 #define MAX31335_TRICKLE_REG 0x1D
58 #define MAX31335_AGING_OFFSET 0x1E
59 #define MAX31335_TS_CONFIG 0x30
60 #define MAX31335_TEMP_ALARM_HIGH_MSB 0x31
61 #define MAX31335_TEMP_ALARM_HIGH_LSB 0x32
62 #define MAX31335_TEMP_ALARM_LOW_MSB 0x33
63 #define MAX31335_TEMP_ALARM_LOW_LSB 0x34
64 #define MAX31335_TEMP_DATA_MSB 0x35
65 #define MAX31335_TEMP_DATA_LSB 0x36
66 #define MAX31335_TS0_SEC_1_128 0x40
67 #define MAX31335_TS0_SEC 0x41
68 #define MAX31335_TS0_MIN 0x42
69 #define MAX31335_TS0_HOUR 0x43
70 #define MAX31335_TS0_DATE 0x44
71 #define MAX31335_TS0_MONTH 0x45
72 #define MAX31335_TS0_YEAR 0x46
73 #define MAX31335_TS0_FLAGS 0x47
74 #define MAX31335_TS1_SEC_1_128 0x48
75 #define MAX31335_TS1_SEC 0x49
76 #define MAX31335_TS1_MIN 0x4A
77 #define MAX31335_TS1_HOUR 0x4B
78 #define MAX31335_TS1_DATE 0x4C
79 #define MAX31335_TS1_MONTH 0x4D
80 #define MAX31335_TS1_YEAR 0x4E
81 #define MAX31335_TS1_FLAGS 0x4F
82 #define MAX31335_TS2_SEC_1_128 0x50
83 #define MAX31335_TS2_SEC 0x51
84 #define MAX31335_TS2_MIN 0x52
85 #define MAX31335_TS2_HOUR 0x53
86 #define MAX31335_TS2_DATE 0x54
87 #define MAX31335_TS2_MONTH 0x55
88 #define MAX31335_TS2_YEAR 0x56
89 #define MAX31335_TS2_FLAGS 0x57
90 #define MAX31335_TS3_SEC_1_128 0x58
91 #define MAX31335_TS3_SEC 0x59
92 #define MAX31335_TS3_MIN 0x5A
93 #define MAX31335_TS3_HOUR 0x5B
94 #define MAX31335_TS3_DATE 0x5C
95 #define MAX31335_TS3_MONTH 0x5D
96 #define MAX31335_TS3_YEAR 0x5E
97 #define MAX31335_TS3_FLAGS 0x5F
98
99 /* MAX31335_STATUS1 Bit Definitions */
100 #define MAX31335_STATUS1_PSDECT BIT(7)
101 #define MAX31335_STATUS1_OSF BIT(6)
102 #define MAX31335_STATUS1_PFAIL BIT(5)
103 #define MAX31335_STATUS1_VBATLOW BIT(4)
104 #define MAX31335_STATUS1_DIF BIT(3)
105 #define MAX31335_STATUS1_TIF BIT(2)
106 #define MAX31335_STATUS1_A2F BIT(1)
107 #define MAX31335_STATUS1_A1F BIT(0)
108
109 /* MAX31335_INT_EN1 Bit Definitions */
110 #define MAX31335_INT_EN1_DOSF BIT(6)
111 #define MAX31335_INT_EN1_PFAILE BIT(5)
112 #define MAX31335_INT_EN1_VBATLOWE BIT(4)
113 #define MAX31335_INT_EN1_DIE BIT(3)
114 #define MAX31335_INT_EN1_TIE BIT(2)
115 #define MAX31335_INT_EN1_A2IE BIT(1)
116 #define MAX31335_INT_EN1_A1IE BIT(0)
117
118 /* MAX31335_STATUS2 Bit Definitions */
119 #define MAX31335_STATUS2_TEMP_RDY BIT(2)
120 #define MAX31335_STATUS2_OTF BIT(1)
121 #define MAX31335_STATUS2_UTF BIT(0)
122
123 /* MAX31335_INT_EN2 Bit Definitions */
124 #define MAX31335_INT_EN2_TEMP_RDY_EN BIT(2)
125 #define MAX31335_INT_EN2_OTIE BIT(1)
126 #define MAX31335_INT_EN2_UTIE BIT(0)
127
128 /* MAX31335_RTC_RESET Bit Definitions */
129 #define MAX31335_RTC_RESET_SWRST BIT(0)
130
131 /* MAX31335_RTC_CONFIG1 Bit Definitions */
132 #define MAX31335_RTC_CONFIG1_EN_IO BIT(6)
133 #define MAX31335_RTC_CONFIG1_A1AC GENMASK(5, 4)
134 #define MAX31335_RTC_CONFIG1_DIP BIT(3)
135 #define MAX31335_RTC_CONFIG1_I2C_TIMEOUT BIT(1)
136 #define MAX31335_RTC_CONFIG1_EN_OSC BIT(0)
137
138 /* MAX31335_RTC_CONFIG2 Bit Definitions */
139 #define MAX31335_RTC_CONFIG2_ENCLKO BIT(2)
140 #define MAX31335_RTC_CONFIG2_CLKO_HZ GENMASK(1, 0)
141
142 /* MAX31335_TIMESTAMP_CONFIG Bit Definitions */
143 #define MAX31335_TIMESTAMP_CONFIG_TSVLOW BIT(5)
144 #define MAX31335_TIMESTAMP_CONFIG_TSPWM BIT(4)
145 #define MAX31335_TIMESTAMP_CONFIG_TSDIN BIT(3)
146 #define MAX31335_TIMESTAMP_CONFIG_TSOW BIT(2)
147 #define MAX31335_TIMESTAMP_CONFIG_TSR BIT(1)
148 #define MAX31335_TIMESTAMP_CONFIG_TSE BIT(0)
149
150 /* MAX31335_TIMER_CONFIG Bit Definitions */
151 #define MAX31335_TIMER_CONFIG_TE BIT(4)
152 #define MAX31335_TIMER_CONFIG_TPAUSE BIT(3)
153 #define MAX31335_TIMER_CONFIG_TRPT BIT(2)
154 #define MAX31335_TIMER_CONFIG_TFS GENMASK(1, 0)
155
156 /* MAX31335_HOURS Bit Definitions */
157 #define MAX31335_HOURS_F_24_12 BIT(6)
158 #define MAX31335_HOURS_HR_20_AM_PM BIT(5)
159
160 /* MAX31335_MONTH Bit Definitions */
161 #define MAX31335_MONTH_CENTURY BIT(7)
162
163 /* MAX31335_PWR_MGMT Bit Definitions */
164 #define MAX31335_PWR_MGMT_PFVT BIT(0)
165
166 /* MAX31335_TRICKLE_REG Bit Definitions */
167 #define MAX31335_TRICKLE_REG_TRICKLE GENMASK(3, 1)
168 #define MAX31335_TRICKLE_REG_EN_TRICKLE BIT(0)
169
170 /* MAX31335_TS_CONFIG Bit Definitions */
171 #define MAX31335_TS_CONFIG_AUTO BIT(4)
172 #define MAX31335_TS_CONFIG_CONVERT_T BIT(3)
173 #define MAX31335_TS_CONFIG_TSINT GENMASK(2, 0)
174
175 /* MAX31335_TS_FLAGS Bit Definitions */
176 #define MAX31335_TS_FLAGS_VLOWF BIT(3)
177 #define MAX31335_TS_FLAGS_VBATF BIT(2)
178 #define MAX31335_TS_FLAGS_VCCF BIT(1)
179 #define MAX31335_TS_FLAGS_DINF BIT(0)
180
181 /* MAX31335 Miscellaneous Definitions */
182 #define MAX31335_TRICKLE_SCHOTTKY_DIODE 1
183 #define MAX31335_TRICKLE_STANDARD_DIODE 4
184 #define MAX31335_RAM_SIZE 32
185 #define MAX31335_TIME_SIZE 0x07
186
187 /* MAX31331 Register Map */
188 #define MAX31331_RTC_CONFIG2 0x04
189
190 #define clk_hw_to_max31335(_hw) container_of(_hw, struct max31335_data, clkout)
191
192 /* Supported Maxim RTC */
193 enum max_rtc_ids {
194 ID_MAX31331,
195 ID_MAX31335,
196 MAX_RTC_ID_NR
197 };
198
199 struct chip_desc {
200 u8 sec_reg;
201 u8 alarm1_sec_reg;
202
203 u8 int_en_reg;
204 u8 int_status_reg;
205
206 u8 ram_reg;
207 u8 ram_size;
208
209 u8 temp_reg;
210
211 u8 trickle_reg;
212
213 u8 clkout_reg;
214
215 enum max_rtc_ids id;
216 };
217
218 struct max31335_data {
219 struct regmap *regmap;
220 struct rtc_device *rtc;
221 struct clk_hw clkout;
222 struct clk *clkin;
223 const struct chip_desc *chip;
224 int irq;
225 };
226
227 static const int max31335_clkout_freq[] = { 1, 64, 1024, 32768 };
228
229 static const struct chip_desc chip[MAX_RTC_ID_NR] = {
230 [ID_MAX31331] = {
231 .id = ID_MAX31331,
232 .int_en_reg = 0x01,
233 .int_status_reg = 0x00,
234 .sec_reg = 0x08,
235 .alarm1_sec_reg = 0x0F,
236 .ram_reg = 0x20,
237 .ram_size = 32,
238 .trickle_reg = 0x1B,
239 .clkout_reg = 0x04,
240 },
241 [ID_MAX31335] = {
242 .id = ID_MAX31335,
243 .int_en_reg = 0x01,
244 .int_status_reg = 0x00,
245 .sec_reg = 0x0A,
246 .alarm1_sec_reg = 0x11,
247 .ram_reg = 0x40,
248 .ram_size = 32,
249 .temp_reg = 0x35,
250 .trickle_reg = 0x1D,
251 .clkout_reg = 0x06,
252 },
253 };
254
255 static const u16 max31335_trickle_resistors[] = {3000, 6000, 11000};
256
max31335_volatile_reg(struct device * dev,unsigned int reg)257 static bool max31335_volatile_reg(struct device *dev, unsigned int reg)
258 {
259 struct max31335_data *max31335 = dev_get_drvdata(dev);
260 const struct chip_desc *chip = max31335->chip;
261
262 /* time keeping registers */
263 if (reg >= chip->sec_reg && reg < chip->sec_reg + MAX31335_TIME_SIZE)
264 return true;
265
266 /* interrupt status register */
267 if (reg == chip->int_status_reg)
268 return true;
269
270 /* temperature registers if valid */
271 if (chip->temp_reg && (reg == chip->temp_reg || reg == chip->temp_reg + 1))
272 return true;
273
274 return false;
275 }
276
277 static const struct regmap_config regmap_config = {
278 .reg_bits = 8,
279 .val_bits = 8,
280 .max_register = 0x5F,
281 .volatile_reg = max31335_volatile_reg,
282 };
283
max31335_read_time(struct device * dev,struct rtc_time * tm)284 static int max31335_read_time(struct device *dev, struct rtc_time *tm)
285 {
286 struct max31335_data *max31335 = dev_get_drvdata(dev);
287 u8 date[7];
288 int ret;
289
290 ret = regmap_bulk_read(max31335->regmap, max31335->chip->sec_reg, date,
291 sizeof(date));
292 if (ret)
293 return ret;
294
295 tm->tm_sec = bcd2bin(date[0] & 0x7f);
296 tm->tm_min = bcd2bin(date[1] & 0x7f);
297 tm->tm_hour = bcd2bin(date[2] & 0x3f);
298 tm->tm_wday = bcd2bin(date[3] & 0x7) - 1;
299 tm->tm_mday = bcd2bin(date[4] & 0x3f);
300 tm->tm_mon = bcd2bin(date[5] & 0x1f) - 1;
301 tm->tm_year = bcd2bin(date[6]) + 100;
302
303 if (FIELD_GET(MAX31335_MONTH_CENTURY, date[5]))
304 tm->tm_year += 100;
305
306 return 0;
307 }
308
max31335_set_time(struct device * dev,struct rtc_time * tm)309 static int max31335_set_time(struct device *dev, struct rtc_time *tm)
310 {
311 struct max31335_data *max31335 = dev_get_drvdata(dev);
312 u8 date[7];
313
314 date[0] = bin2bcd(tm->tm_sec);
315 date[1] = bin2bcd(tm->tm_min);
316 date[2] = bin2bcd(tm->tm_hour);
317 date[3] = bin2bcd(tm->tm_wday + 1);
318 date[4] = bin2bcd(tm->tm_mday);
319 date[5] = bin2bcd(tm->tm_mon + 1);
320 date[6] = bin2bcd(tm->tm_year % 100);
321
322 if (tm->tm_year >= 200)
323 date[5] |= FIELD_PREP(MAX31335_MONTH_CENTURY, 1);
324
325 return regmap_bulk_write(max31335->regmap, max31335->chip->sec_reg, date,
326 sizeof(date));
327 }
328
max31335_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)329 static int max31335_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
330 {
331 struct max31335_data *max31335 = dev_get_drvdata(dev);
332 int ret, ctrl, status;
333 struct rtc_time time;
334 u8 regs[6];
335
336 ret = regmap_bulk_read(max31335->regmap, max31335->chip->alarm1_sec_reg, regs,
337 sizeof(regs));
338 if (ret)
339 return ret;
340
341 alrm->time.tm_sec = bcd2bin(regs[0] & 0x7f);
342 alrm->time.tm_min = bcd2bin(regs[1] & 0x7f);
343 alrm->time.tm_hour = bcd2bin(regs[2] & 0x3f);
344 alrm->time.tm_mday = bcd2bin(regs[3] & 0x3f);
345 alrm->time.tm_mon = bcd2bin(regs[4] & 0x1f) - 1;
346 alrm->time.tm_year = bcd2bin(regs[5]) + 100;
347
348 ret = max31335_read_time(dev, &time);
349 if (ret)
350 return ret;
351
352 if (time.tm_year >= 200)
353 alrm->time.tm_year += 100;
354
355 ret = regmap_read(max31335->regmap, max31335->chip->int_en_reg, &ctrl);
356 if (ret)
357 return ret;
358
359 ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);
360 if (ret)
361 return ret;
362
363 alrm->enabled = FIELD_GET(MAX31335_INT_EN1_A1IE, ctrl);
364 alrm->pending = FIELD_GET(MAX31335_STATUS1_A1F, status);
365
366 return 0;
367 }
368
max31335_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)369 static int max31335_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
370 {
371 struct max31335_data *max31335 = dev_get_drvdata(dev);
372 unsigned int reg;
373 u8 regs[6];
374 int ret;
375
376 regs[0] = bin2bcd(alrm->time.tm_sec);
377 regs[1] = bin2bcd(alrm->time.tm_min);
378 regs[2] = bin2bcd(alrm->time.tm_hour);
379 regs[3] = bin2bcd(alrm->time.tm_mday);
380 regs[4] = bin2bcd(alrm->time.tm_mon + 1);
381 regs[5] = bin2bcd(alrm->time.tm_year % 100);
382
383 ret = regmap_bulk_write(max31335->regmap, max31335->chip->alarm1_sec_reg,
384 regs, sizeof(regs));
385 if (ret)
386 return ret;
387
388 reg = FIELD_PREP(MAX31335_INT_EN1_A1IE, alrm->enabled);
389 ret = regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,
390 MAX31335_INT_EN1_A1IE, reg);
391 if (ret)
392 return ret;
393
394 ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,
395 MAX31335_STATUS1_A1F, 0);
396
397 return 0;
398 }
399
max31335_alarm_irq_enable(struct device * dev,unsigned int enabled)400 static int max31335_alarm_irq_enable(struct device *dev, unsigned int enabled)
401 {
402 struct max31335_data *max31335 = dev_get_drvdata(dev);
403
404 return regmap_update_bits(max31335->regmap, max31335->chip->int_en_reg,
405 MAX31335_INT_EN1_A1IE, enabled);
406 }
407
max31335_handle_irq(int irq,void * dev_id)408 static irqreturn_t max31335_handle_irq(int irq, void *dev_id)
409 {
410 struct max31335_data *max31335 = dev_id;
411 struct mutex *lock = &max31335->rtc->ops_lock;
412 int ret, status;
413
414 mutex_lock(lock);
415
416 ret = regmap_read(max31335->regmap, max31335->chip->int_status_reg, &status);
417 if (ret)
418 goto exit;
419
420 if (FIELD_GET(MAX31335_STATUS1_A1F, status)) {
421 ret = regmap_update_bits(max31335->regmap, max31335->chip->int_status_reg,
422 MAX31335_STATUS1_A1F, 0);
423 if (ret)
424 goto exit;
425
426 rtc_update_irq(max31335->rtc, 1, RTC_AF | RTC_IRQF);
427 }
428
429 exit:
430 mutex_unlock(lock);
431
432 return IRQ_HANDLED;
433 }
434
435 static const struct rtc_class_ops max31335_rtc_ops = {
436 .read_time = max31335_read_time,
437 .set_time = max31335_set_time,
438 .read_alarm = max31335_read_alarm,
439 .set_alarm = max31335_set_alarm,
440 .alarm_irq_enable = max31335_alarm_irq_enable,
441 };
442
max31335_trickle_charger_setup(struct device * dev,struct max31335_data * max31335)443 static int max31335_trickle_charger_setup(struct device *dev,
444 struct max31335_data *max31335)
445 {
446 u32 ohms, chargeable;
447 int i, trickle_cfg;
448 const char *diode;
449
450 if (device_property_read_u32(dev, "aux-voltage-chargeable",
451 &chargeable))
452 return 0;
453
454 if (device_property_read_u32(dev, "trickle-resistor-ohms", &ohms))
455 return 0;
456
457 if (device_property_read_string(dev, "adi,tc-diode", &diode))
458 return 0;
459
460 if (!strcmp(diode, "schottky"))
461 trickle_cfg = MAX31335_TRICKLE_SCHOTTKY_DIODE;
462 else if (!strcmp(diode, "standard+schottky"))
463 trickle_cfg = MAX31335_TRICKLE_STANDARD_DIODE;
464 else
465 return dev_err_probe(dev, -EINVAL,
466 "Invalid tc-diode value: %s\n", diode);
467
468 for (i = 0; i < ARRAY_SIZE(max31335_trickle_resistors); i++)
469 if (ohms == max31335_trickle_resistors[i])
470 break;
471
472 if (i >= ARRAY_SIZE(max31335_trickle_resistors))
473 return 0;
474
475 i = i + trickle_cfg;
476
477 return regmap_write(max31335->regmap, max31335->chip->trickle_reg,
478 FIELD_PREP(MAX31335_TRICKLE_REG_TRICKLE, i) |
479 FIELD_PREP(MAX31335_TRICKLE_REG_EN_TRICKLE,
480 chargeable));
481 }
482
max31335_clkout_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)483 static unsigned long max31335_clkout_recalc_rate(struct clk_hw *hw,
484 unsigned long parent_rate)
485 {
486 struct max31335_data *max31335 = clk_hw_to_max31335(hw);
487 unsigned int freq_mask;
488 unsigned int reg;
489 int ret;
490
491 ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, ®);
492 if (ret)
493 return 0;
494
495 freq_mask = __roundup_pow_of_two(ARRAY_SIZE(max31335_clkout_freq)) - 1;
496
497 return max31335_clkout_freq[reg & freq_mask];
498 }
499
max31335_clkout_determine_rate(struct clk_hw * hw,struct clk_rate_request * req)500 static int max31335_clkout_determine_rate(struct clk_hw *hw,
501 struct clk_rate_request *req)
502 {
503 int index;
504
505 index = find_closest(req->rate, max31335_clkout_freq,
506 ARRAY_SIZE(max31335_clkout_freq));
507
508 req->rate = max31335_clkout_freq[index];
509
510 return 0;
511 }
512
max31335_clkout_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)513 static int max31335_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
514 unsigned long parent_rate)
515 {
516 struct max31335_data *max31335 = clk_hw_to_max31335(hw);
517 unsigned int freq_mask;
518 int index;
519
520 index = find_closest(rate, max31335_clkout_freq,
521 ARRAY_SIZE(max31335_clkout_freq));
522 freq_mask = __roundup_pow_of_two(ARRAY_SIZE(max31335_clkout_freq)) - 1;
523
524 return regmap_update_bits(max31335->regmap, max31335->chip->clkout_reg,
525 freq_mask, index);
526 }
527
max31335_clkout_enable(struct clk_hw * hw)528 static int max31335_clkout_enable(struct clk_hw *hw)
529 {
530 struct max31335_data *max31335 = clk_hw_to_max31335(hw);
531
532 return regmap_set_bits(max31335->regmap, max31335->chip->clkout_reg,
533 MAX31335_RTC_CONFIG2_ENCLKO);
534 }
535
max31335_clkout_disable(struct clk_hw * hw)536 static void max31335_clkout_disable(struct clk_hw *hw)
537 {
538 struct max31335_data *max31335 = clk_hw_to_max31335(hw);
539
540 regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,
541 MAX31335_RTC_CONFIG2_ENCLKO);
542 }
543
max31335_clkout_is_enabled(struct clk_hw * hw)544 static int max31335_clkout_is_enabled(struct clk_hw *hw)
545 {
546 struct max31335_data *max31335 = clk_hw_to_max31335(hw);
547 unsigned int reg;
548 int ret;
549
550 ret = regmap_read(max31335->regmap, max31335->chip->clkout_reg, ®);
551 if (ret)
552 return ret;
553
554 return !!(reg & MAX31335_RTC_CONFIG2_ENCLKO);
555 }
556
557 static const struct clk_ops max31335_clkout_ops = {
558 .recalc_rate = max31335_clkout_recalc_rate,
559 .determine_rate = max31335_clkout_determine_rate,
560 .set_rate = max31335_clkout_set_rate,
561 .enable = max31335_clkout_enable,
562 .disable = max31335_clkout_disable,
563 .is_enabled = max31335_clkout_is_enabled,
564 };
565
566 static struct clk_init_data max31335_clk_init = {
567 .name = "max31335-clkout",
568 .ops = &max31335_clkout_ops,
569 };
570
max31335_nvmem_reg_read(void * priv,unsigned int offset,void * val,size_t bytes)571 static int max31335_nvmem_reg_read(void *priv, unsigned int offset,
572 void *val, size_t bytes)
573 {
574 struct max31335_data *max31335 = priv;
575 unsigned int reg = max31335->chip->ram_reg + offset;
576
577 return regmap_bulk_read(max31335->regmap, reg, val, bytes);
578 }
579
max31335_nvmem_reg_write(void * priv,unsigned int offset,void * val,size_t bytes)580 static int max31335_nvmem_reg_write(void *priv, unsigned int offset,
581 void *val, size_t bytes)
582 {
583 struct max31335_data *max31335 = priv;
584 unsigned int reg = max31335->chip->ram_reg + offset;
585
586 return regmap_bulk_write(max31335->regmap, reg, val, bytes);
587 }
588
589 static struct nvmem_config max31335_nvmem_cfg = {
590 .reg_read = max31335_nvmem_reg_read,
591 .reg_write = max31335_nvmem_reg_write,
592 .word_size = 8,
593 .size = MAX31335_RAM_SIZE,
594 };
595
596 #if IS_REACHABLE(HWMON)
max31335_read_temp(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)597 static int max31335_read_temp(struct device *dev, enum hwmon_sensor_types type,
598 u32 attr, int channel, long *val)
599 {
600 struct max31335_data *max31335 = dev_get_drvdata(dev);
601 u8 reg[2];
602 s16 temp;
603 int ret;
604
605 if (type != hwmon_temp || attr != hwmon_temp_input)
606 return -EOPNOTSUPP;
607
608 ret = regmap_bulk_read(max31335->regmap, max31335->chip->temp_reg,
609 reg, 2);
610 if (ret)
611 return ret;
612
613 temp = get_unaligned_be16(reg);
614
615 *val = (temp / 64) * 250;
616
617 return 0;
618 }
619
max31335_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)620 static umode_t max31335_is_visible(const void *data,
621 enum hwmon_sensor_types type,
622 u32 attr, int channel)
623 {
624 if (type == hwmon_temp && attr == hwmon_temp_input)
625 return 0444;
626
627 return 0;
628 }
629
630 static const struct hwmon_channel_info *max31335_info[] = {
631 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
632 NULL
633 };
634
635 static const struct hwmon_ops max31335_hwmon_ops = {
636 .is_visible = max31335_is_visible,
637 .read = max31335_read_temp,
638 };
639
640 static const struct hwmon_chip_info max31335_chip_info = {
641 .ops = &max31335_hwmon_ops,
642 .info = max31335_info,
643 };
644 #endif
645
max31335_clkout_register(struct device * dev)646 static int max31335_clkout_register(struct device *dev)
647 {
648 struct max31335_data *max31335 = dev_get_drvdata(dev);
649 int ret;
650
651 if (!device_property_present(dev, "#clock-cells"))
652 return regmap_clear_bits(max31335->regmap, max31335->chip->clkout_reg,
653 MAX31335_RTC_CONFIG2_ENCLKO);
654
655 max31335->clkout.init = &max31335_clk_init;
656
657 ret = devm_clk_hw_register(dev, &max31335->clkout);
658 if (ret)
659 return dev_err_probe(dev, ret, "cannot register clock\n");
660
661 ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
662 &max31335->clkout);
663 if (ret)
664 return dev_err_probe(dev, ret, "cannot add hw provider\n");
665
666 max31335->clkout.clk = devm_clk_get_enabled(dev, NULL);
667 if (IS_ERR(max31335->clkout.clk))
668 return dev_err_probe(dev, PTR_ERR(max31335->clkout.clk),
669 "cannot enable clkout\n");
670
671 return 0;
672 }
673
max31335_probe(struct i2c_client * client)674 static int max31335_probe(struct i2c_client *client)
675 {
676 struct max31335_data *max31335;
677 #if IS_REACHABLE(HWMON)
678 struct device *hwmon;
679 #endif
680 const struct chip_desc *match;
681 int ret;
682
683 max31335 = devm_kzalloc(&client->dev, sizeof(*max31335), GFP_KERNEL);
684 if (!max31335)
685 return -ENOMEM;
686
687 max31335->regmap = devm_regmap_init_i2c(client, ®map_config);
688 if (IS_ERR(max31335->regmap))
689 return PTR_ERR(max31335->regmap);
690
691 i2c_set_clientdata(client, max31335);
692 match = i2c_get_match_data(client);
693 if (!match)
694 return -ENODEV;
695 max31335->chip = match;
696 max31335->rtc = devm_rtc_allocate_device(&client->dev);
697 if (IS_ERR(max31335->rtc))
698 return PTR_ERR(max31335->rtc);
699
700 max31335->rtc->ops = &max31335_rtc_ops;
701 max31335->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
702 max31335->rtc->range_max = RTC_TIMESTAMP_END_2199;
703 max31335->rtc->alarm_offset_max = 24 * 60 * 60;
704
705 ret = max31335_clkout_register(&client->dev);
706 if (ret)
707 return ret;
708
709 if (client->irq > 0) {
710 ret = devm_request_threaded_irq(&client->dev, client->irq,
711 NULL, max31335_handle_irq,
712 IRQF_ONESHOT,
713 "max31335", max31335);
714 if (ret) {
715 dev_warn(&client->dev,
716 "unable to request IRQ, alarm max31335 disabled\n");
717 client->irq = 0;
718 } else {
719 max31335->irq = client->irq;
720 }
721 }
722
723 if (!client->irq)
724 clear_bit(RTC_FEATURE_ALARM, max31335->rtc->features);
725
726 max31335_nvmem_cfg.priv = max31335;
727 ret = devm_rtc_nvmem_register(max31335->rtc, &max31335_nvmem_cfg);
728 if (ret)
729 return dev_err_probe(&client->dev, ret,
730 "cannot register rtc nvmem\n");
731
732 #if IS_REACHABLE(HWMON)
733 if (max31335->chip->temp_reg) {
734 hwmon = devm_hwmon_device_register_with_info(&client->dev, client->name, max31335,
735 &max31335_chip_info, NULL);
736 if (IS_ERR(hwmon))
737 return dev_err_probe(&client->dev, PTR_ERR(hwmon),
738 "cannot register hwmon device\n");
739 }
740 #endif
741
742 ret = max31335_trickle_charger_setup(&client->dev, max31335);
743 if (ret)
744 return ret;
745
746 return devm_rtc_register_device(max31335->rtc);
747 }
748
749 static const struct i2c_device_id max31335_id[] = {
750 { "max31331", (kernel_ulong_t)&chip[ID_MAX31331] },
751 { "max31335", (kernel_ulong_t)&chip[ID_MAX31335] },
752 { }
753 };
754
755 MODULE_DEVICE_TABLE(i2c, max31335_id);
756
757 static const struct of_device_id max31335_of_match[] = {
758 { .compatible = "adi,max31331", .data = &chip[ID_MAX31331] },
759 { .compatible = "adi,max31335", .data = &chip[ID_MAX31335] },
760 { }
761 };
762
763 MODULE_DEVICE_TABLE(of, max31335_of_match);
764
765 static struct i2c_driver max31335_driver = {
766 .driver = {
767 .name = "rtc-max31335",
768 .of_match_table = max31335_of_match,
769 },
770 .probe = max31335_probe,
771 .id_table = max31335_id,
772 };
773 module_i2c_driver(max31335_driver);
774
775 MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
776 MODULE_AUTHOR("Saket Kumar Purwar <Saket.Kumarpurwar@analog.com>");
777 MODULE_DESCRIPTION("MAX31335 RTC driver");
778 MODULE_LICENSE("GPL");
779