1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * drivers/rtc/rtc-pcf85363.c
4 *
5 * Driver for NXP PCF85363 real-time clock.
6 *
7 * Copyright (C) 2017 Eric Nelson
8 */
9 #include <linux/module.h>
10 #include <linux/i2c.h>
11 #include <linux/slab.h>
12 #include <linux/rtc.h>
13 #include <linux/init.h>
14 #include <linux/err.h>
15 #include <linux/errno.h>
16 #include <linux/bcd.h>
17 #include <linux/of.h>
18 #include <linux/of_device.h>
19 #include <linux/regmap.h>
20
21 /*
22 * Date/Time registers
23 */
24 #define DT_100THS 0x00
25 #define DT_SECS 0x01
26 #define DT_MINUTES 0x02
27 #define DT_HOURS 0x03
28 #define DT_DAYS 0x04
29 #define DT_WEEKDAYS 0x05
30 #define DT_MONTHS 0x06
31 #define DT_YEARS 0x07
32
33 /*
34 * Alarm registers
35 */
36 #define DT_SECOND_ALM1 0x08
37 #define DT_MINUTE_ALM1 0x09
38 #define DT_HOUR_ALM1 0x0a
39 #define DT_DAY_ALM1 0x0b
40 #define DT_MONTH_ALM1 0x0c
41 #define DT_MINUTE_ALM2 0x0d
42 #define DT_HOUR_ALM2 0x0e
43 #define DT_WEEKDAY_ALM2 0x0f
44 #define DT_ALARM_EN 0x10
45
46 /*
47 * Time stamp registers
48 */
49 #define DT_TIMESTAMP1 0x11
50 #define DT_TIMESTAMP2 0x17
51 #define DT_TIMESTAMP3 0x1d
52 #define DT_TS_MODE 0x23
53
54 /*
55 * control registers
56 */
57 #define CTRL_OFFSET 0x24
58 #define CTRL_OSCILLATOR 0x25
59 #define CTRL_BATTERY 0x26
60 #define CTRL_PIN_IO 0x27
61 #define CTRL_FUNCTION 0x28
62 #define CTRL_INTA_EN 0x29
63 #define CTRL_INTB_EN 0x2a
64 #define CTRL_FLAGS 0x2b
65 #define CTRL_RAMBYTE 0x2c
66 #define CTRL_WDOG 0x2d
67 #define CTRL_STOP_EN 0x2e
68 #define CTRL_RESETS 0x2f
69 #define CTRL_RAM 0x40
70
71 #define ALRM_SEC_A1E BIT(0)
72 #define ALRM_MIN_A1E BIT(1)
73 #define ALRM_HR_A1E BIT(2)
74 #define ALRM_DAY_A1E BIT(3)
75 #define ALRM_MON_A1E BIT(4)
76 #define ALRM_MIN_A2E BIT(5)
77 #define ALRM_HR_A2E BIT(6)
78 #define ALRM_DAY_A2E BIT(7)
79
80 #define INT_WDIE BIT(0)
81 #define INT_BSIE BIT(1)
82 #define INT_TSRIE BIT(2)
83 #define INT_A2IE BIT(3)
84 #define INT_A1IE BIT(4)
85 #define INT_OIE BIT(5)
86 #define INT_PIE BIT(6)
87 #define INT_ILP BIT(7)
88
89 #define FLAGS_TSR1F BIT(0)
90 #define FLAGS_TSR2F BIT(1)
91 #define FLAGS_TSR3F BIT(2)
92 #define FLAGS_BSF BIT(3)
93 #define FLAGS_WDF BIT(4)
94 #define FLAGS_A1F BIT(5)
95 #define FLAGS_A2F BIT(6)
96 #define FLAGS_PIF BIT(7)
97
98 #define PIN_IO_INTAPM GENMASK(1, 0)
99 #define PIN_IO_INTA_CLK 0
100 #define PIN_IO_INTA_BAT 1
101 #define PIN_IO_INTA_OUT 2
102 #define PIN_IO_INTA_HIZ 3
103
104 #define STOP_EN_STOP BIT(0)
105
106 #define RESET_CPR 0xa4
107
108 #define NVRAM_SIZE 0x40
109
110 struct pcf85363 {
111 struct rtc_device *rtc;
112 struct regmap *regmap;
113 };
114
115 struct pcf85x63_config {
116 struct regmap_config regmap;
117 unsigned int num_nvram;
118 };
119
pcf85363_rtc_read_time(struct device * dev,struct rtc_time * tm)120 static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
121 {
122 struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
123 unsigned char buf[DT_YEARS + 1];
124 int ret, len = sizeof(buf);
125
126 /* read the RTC date and time registers all at once */
127 ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len);
128 if (ret) {
129 dev_err(dev, "%s: error %d\n", __func__, ret);
130 return ret;
131 }
132
133 tm->tm_year = bcd2bin(buf[DT_YEARS]);
134 /* adjust for 1900 base of rtc_time */
135 tm->tm_year += 100;
136
137 tm->tm_wday = buf[DT_WEEKDAYS] & 7;
138 buf[DT_SECS] &= 0x7F;
139 tm->tm_sec = bcd2bin(buf[DT_SECS]);
140 buf[DT_MINUTES] &= 0x7F;
141 tm->tm_min = bcd2bin(buf[DT_MINUTES]);
142 tm->tm_hour = bcd2bin(buf[DT_HOURS]);
143 tm->tm_mday = bcd2bin(buf[DT_DAYS]);
144 tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1;
145
146 return 0;
147 }
148
pcf85363_rtc_set_time(struct device * dev,struct rtc_time * tm)149 static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
150 {
151 struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
152 unsigned char tmp[11];
153 unsigned char *buf = &tmp[2];
154 int ret;
155
156 tmp[0] = STOP_EN_STOP;
157 tmp[1] = RESET_CPR;
158
159 buf[DT_100THS] = 0;
160 buf[DT_SECS] = bin2bcd(tm->tm_sec);
161 buf[DT_MINUTES] = bin2bcd(tm->tm_min);
162 buf[DT_HOURS] = bin2bcd(tm->tm_hour);
163 buf[DT_DAYS] = bin2bcd(tm->tm_mday);
164 buf[DT_WEEKDAYS] = tm->tm_wday;
165 buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1);
166 buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
167
168 ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN,
169 tmp, 2);
170 if (ret)
171 return ret;
172
173 ret = regmap_bulk_write(pcf85363->regmap, DT_100THS,
174 buf, sizeof(tmp) - 2);
175 if (ret)
176 return ret;
177
178 return regmap_write(pcf85363->regmap, CTRL_STOP_EN, 0);
179 }
180
pcf85363_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)181 static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
182 {
183 struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
184 unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
185 unsigned int val;
186 int ret;
187
188 ret = regmap_bulk_read(pcf85363->regmap, DT_SECOND_ALM1, buf,
189 sizeof(buf));
190 if (ret)
191 return ret;
192
193 alrm->time.tm_sec = bcd2bin(buf[0]);
194 alrm->time.tm_min = bcd2bin(buf[1]);
195 alrm->time.tm_hour = bcd2bin(buf[2]);
196 alrm->time.tm_mday = bcd2bin(buf[3]);
197 alrm->time.tm_mon = bcd2bin(buf[4]) - 1;
198
199 ret = regmap_read(pcf85363->regmap, CTRL_INTA_EN, &val);
200 if (ret)
201 return ret;
202
203 alrm->enabled = !!(val & INT_A1IE);
204
205 return 0;
206 }
207
_pcf85363_rtc_alarm_irq_enable(struct pcf85363 * pcf85363,unsigned int enabled)208 static int _pcf85363_rtc_alarm_irq_enable(struct pcf85363 *pcf85363, unsigned
209 int enabled)
210 {
211 unsigned int alarm_flags = ALRM_SEC_A1E | ALRM_MIN_A1E | ALRM_HR_A1E |
212 ALRM_DAY_A1E | ALRM_MON_A1E;
213 int ret;
214
215 ret = regmap_update_bits(pcf85363->regmap, DT_ALARM_EN, alarm_flags,
216 enabled ? alarm_flags : 0);
217 if (ret)
218 return ret;
219
220 ret = regmap_update_bits(pcf85363->regmap, CTRL_INTA_EN,
221 INT_A1IE, enabled ? INT_A1IE : 0);
222
223 if (ret || enabled)
224 return ret;
225
226 /* clear current flags */
227 return regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
228 }
229
pcf85363_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)230 static int pcf85363_rtc_alarm_irq_enable(struct device *dev,
231 unsigned int enabled)
232 {
233 struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
234
235 return _pcf85363_rtc_alarm_irq_enable(pcf85363, enabled);
236 }
237
pcf85363_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)238 static int pcf85363_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
239 {
240 struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
241 unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
242 int ret;
243
244 buf[0] = bin2bcd(alrm->time.tm_sec);
245 buf[1] = bin2bcd(alrm->time.tm_min);
246 buf[2] = bin2bcd(alrm->time.tm_hour);
247 buf[3] = bin2bcd(alrm->time.tm_mday);
248 buf[4] = bin2bcd(alrm->time.tm_mon + 1);
249
250 /*
251 * Disable the alarm interrupt before changing the value to avoid
252 * spurious interrupts
253 */
254 ret = _pcf85363_rtc_alarm_irq_enable(pcf85363, 0);
255 if (ret)
256 return ret;
257
258 ret = regmap_bulk_write(pcf85363->regmap, DT_SECOND_ALM1, buf,
259 sizeof(buf));
260 if (ret)
261 return ret;
262
263 return _pcf85363_rtc_alarm_irq_enable(pcf85363, alrm->enabled);
264 }
265
pcf85363_rtc_handle_irq(int irq,void * dev_id)266 static irqreturn_t pcf85363_rtc_handle_irq(int irq, void *dev_id)
267 {
268 struct pcf85363 *pcf85363 = i2c_get_clientdata(dev_id);
269 unsigned int flags;
270 int err;
271
272 err = regmap_read(pcf85363->regmap, CTRL_FLAGS, &flags);
273 if (err)
274 return IRQ_NONE;
275
276 if (flags & FLAGS_A1F) {
277 rtc_update_irq(pcf85363->rtc, 1, RTC_IRQF | RTC_AF);
278 regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
279 return IRQ_HANDLED;
280 }
281
282 return IRQ_NONE;
283 }
284
285 static const struct rtc_class_ops rtc_ops = {
286 .read_time = pcf85363_rtc_read_time,
287 .set_time = pcf85363_rtc_set_time,
288 .read_alarm = pcf85363_rtc_read_alarm,
289 .set_alarm = pcf85363_rtc_set_alarm,
290 .alarm_irq_enable = pcf85363_rtc_alarm_irq_enable,
291 };
292
pcf85363_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)293 static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
294 size_t bytes)
295 {
296 struct pcf85363 *pcf85363 = priv;
297
298 return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset,
299 val, bytes);
300 }
301
pcf85363_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)302 static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
303 size_t bytes)
304 {
305 struct pcf85363 *pcf85363 = priv;
306
307 return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset,
308 val, bytes);
309 }
310
pcf85x63_nvram_read(void * priv,unsigned int offset,void * val,size_t bytes)311 static int pcf85x63_nvram_read(void *priv, unsigned int offset, void *val,
312 size_t bytes)
313 {
314 struct pcf85363 *pcf85363 = priv;
315 unsigned int tmp_val;
316 int ret;
317
318 ret = regmap_read(pcf85363->regmap, CTRL_RAMBYTE, &tmp_val);
319 (*(unsigned char *) val) = (unsigned char) tmp_val;
320
321 return ret;
322 }
323
pcf85x63_nvram_write(void * priv,unsigned int offset,void * val,size_t bytes)324 static int pcf85x63_nvram_write(void *priv, unsigned int offset, void *val,
325 size_t bytes)
326 {
327 struct pcf85363 *pcf85363 = priv;
328 unsigned char tmp_val;
329
330 tmp_val = *((unsigned char *)val);
331 return regmap_write(pcf85363->regmap, CTRL_RAMBYTE,
332 (unsigned int)tmp_val);
333 }
334
335 static const struct pcf85x63_config pcf_85263_config = {
336 .regmap = {
337 .reg_bits = 8,
338 .val_bits = 8,
339 .max_register = 0x2f,
340 },
341 .num_nvram = 1
342 };
343
344 static const struct pcf85x63_config pcf_85363_config = {
345 .regmap = {
346 .reg_bits = 8,
347 .val_bits = 8,
348 .max_register = 0x7f,
349 },
350 .num_nvram = 2
351 };
352
pcf85363_probe(struct i2c_client * client,const struct i2c_device_id * id)353 static int pcf85363_probe(struct i2c_client *client,
354 const struct i2c_device_id *id)
355 {
356 struct pcf85363 *pcf85363;
357 const struct pcf85x63_config *config = &pcf_85363_config;
358 const void *data = of_device_get_match_data(&client->dev);
359 static struct nvmem_config nvmem_cfg[] = {
360 {
361 .name = "pcf85x63-",
362 .word_size = 1,
363 .stride = 1,
364 .size = 1,
365 .reg_read = pcf85x63_nvram_read,
366 .reg_write = pcf85x63_nvram_write,
367 }, {
368 .name = "pcf85363-",
369 .word_size = 1,
370 .stride = 1,
371 .size = NVRAM_SIZE,
372 .reg_read = pcf85363_nvram_read,
373 .reg_write = pcf85363_nvram_write,
374 },
375 };
376 int ret, i;
377
378 if (data)
379 config = data;
380
381 pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363),
382 GFP_KERNEL);
383 if (!pcf85363)
384 return -ENOMEM;
385
386 pcf85363->regmap = devm_regmap_init_i2c(client, &config->regmap);
387 if (IS_ERR(pcf85363->regmap)) {
388 dev_err(&client->dev, "regmap allocation failed\n");
389 return PTR_ERR(pcf85363->regmap);
390 }
391
392 i2c_set_clientdata(client, pcf85363);
393
394 pcf85363->rtc = devm_rtc_allocate_device(&client->dev);
395 if (IS_ERR(pcf85363->rtc))
396 return PTR_ERR(pcf85363->rtc);
397
398 pcf85363->rtc->ops = &rtc_ops;
399 pcf85363->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
400 pcf85363->rtc->range_max = RTC_TIMESTAMP_END_2099;
401 clear_bit(RTC_FEATURE_ALARM, pcf85363->rtc->features);
402
403 if (client->irq > 0) {
404 regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
405 regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
406 PIN_IO_INTA_OUT, PIN_IO_INTAPM);
407 ret = devm_request_threaded_irq(&client->dev, client->irq,
408 NULL, pcf85363_rtc_handle_irq,
409 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
410 "pcf85363", client);
411 if (ret)
412 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
413 else
414 set_bit(RTC_FEATURE_ALARM, pcf85363->rtc->features);
415 }
416
417 ret = devm_rtc_register_device(pcf85363->rtc);
418
419 for (i = 0; i < config->num_nvram; i++) {
420 nvmem_cfg[i].priv = pcf85363;
421 devm_rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg[i]);
422 }
423
424 return ret;
425 }
426
427 static const __maybe_unused struct of_device_id dev_ids[] = {
428 { .compatible = "nxp,pcf85263", .data = &pcf_85263_config },
429 { .compatible = "nxp,pcf85363", .data = &pcf_85363_config },
430 { /* sentinel */ }
431 };
432 MODULE_DEVICE_TABLE(of, dev_ids);
433
434 static struct i2c_driver pcf85363_driver = {
435 .driver = {
436 .name = "pcf85363",
437 .of_match_table = of_match_ptr(dev_ids),
438 },
439 .probe = pcf85363_probe,
440 };
441
442 module_i2c_driver(pcf85363_driver);
443
444 MODULE_AUTHOR("Eric Nelson");
445 MODULE_DESCRIPTION("pcf85263/pcf85363 I2C RTC driver");
446 MODULE_LICENSE("GPL");
447