Merge tag 'perf-tools-for-v5.15-2021-09-11' of git://git.kernel.org/pub/scm/linux...
[linux-2.6-microblaze.git] / drivers / rtc / rtc-pcf8563.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * An I2C driver for the Philips PCF8563 RTC
4  * Copyright 2005-06 Tower Technologies
5  *
6  * Author: Alessandro Zummo <a.zummo@towertech.it>
7  * Maintainers: http://www.nslu2-linux.org/
8  *
9  * based on the other drivers in this same directory.
10  *
11  * https://www.nxp.com/docs/en/data-sheet/PCF8563.pdf
12  */
13
14 #include <linux/clk-provider.h>
15 #include <linux/i2c.h>
16 #include <linux/bcd.h>
17 #include <linux/rtc.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/err.h>
22
23 #define PCF8563_REG_ST1         0x00 /* status */
24 #define PCF8563_REG_ST2         0x01
25 #define PCF8563_BIT_AIE         BIT(1)
26 #define PCF8563_BIT_AF          BIT(3)
27 #define PCF8563_BITS_ST2_N      (7 << 5)
28
29 #define PCF8563_REG_SC          0x02 /* datetime */
30 #define PCF8563_REG_MN          0x03
31 #define PCF8563_REG_HR          0x04
32 #define PCF8563_REG_DM          0x05
33 #define PCF8563_REG_DW          0x06
34 #define PCF8563_REG_MO          0x07
35 #define PCF8563_REG_YR          0x08
36
37 #define PCF8563_REG_AMN         0x09 /* alarm */
38
39 #define PCF8563_REG_CLKO                0x0D /* clock out */
40 #define PCF8563_REG_CLKO_FE             0x80 /* clock out enabled */
41 #define PCF8563_REG_CLKO_F_MASK         0x03 /* frequenc mask */
42 #define PCF8563_REG_CLKO_F_32768HZ      0x00
43 #define PCF8563_REG_CLKO_F_1024HZ       0x01
44 #define PCF8563_REG_CLKO_F_32HZ         0x02
45 #define PCF8563_REG_CLKO_F_1HZ          0x03
46
47 #define PCF8563_REG_TMRC        0x0E /* timer control */
48 #define PCF8563_TMRC_ENABLE     BIT(7)
49 #define PCF8563_TMRC_4096       0
50 #define PCF8563_TMRC_64         1
51 #define PCF8563_TMRC_1          2
52 #define PCF8563_TMRC_1_60       3
53 #define PCF8563_TMRC_MASK       3
54
55 #define PCF8563_REG_TMR         0x0F /* timer */
56
57 #define PCF8563_SC_LV           0x80 /* low voltage */
58 #define PCF8563_MO_C            0x80 /* century */
59
60 static struct i2c_driver pcf8563_driver;
61
62 struct pcf8563 {
63         struct rtc_device *rtc;
64         /*
65          * The meaning of MO_C bit varies by the chip type.
66          * From PCF8563 datasheet: this bit is toggled when the years
67          * register overflows from 99 to 00
68          *   0 indicates the century is 20xx
69          *   1 indicates the century is 19xx
70          * From RTC8564 datasheet: this bit indicates change of
71          * century. When the year digit data overflows from 99 to 00,
72          * this bit is set. By presetting it to 0 while still in the
73          * 20th century, it will be set in year 2000, ...
74          * There seems no reliable way to know how the system use this
75          * bit.  So let's do it heuristically, assuming we are live in
76          * 1970...2069.
77          */
78         int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
79
80         struct i2c_client *client;
81 #ifdef CONFIG_COMMON_CLK
82         struct clk_hw           clkout_hw;
83 #endif
84 };
85
86 static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
87                                    unsigned char length, unsigned char *buf)
88 {
89         struct i2c_msg msgs[] = {
90                 {/* setup read ptr */
91                         .addr = client->addr,
92                         .len = 1,
93                         .buf = &reg,
94                 },
95                 {
96                         .addr = client->addr,
97                         .flags = I2C_M_RD,
98                         .len = length,
99                         .buf = buf
100                 },
101         };
102
103         if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
104                 dev_err(&client->dev, "%s: read error\n", __func__);
105                 return -EIO;
106         }
107
108         return 0;
109 }
110
111 static int pcf8563_write_block_data(struct i2c_client *client,
112                                    unsigned char reg, unsigned char length,
113                                    unsigned char *buf)
114 {
115         int i, err;
116
117         for (i = 0; i < length; i++) {
118                 unsigned char data[2] = { reg + i, buf[i] };
119
120                 err = i2c_master_send(client, data, sizeof(data));
121                 if (err != sizeof(data)) {
122                         dev_err(&client->dev,
123                                 "%s: err=%d addr=%02x, data=%02x\n",
124                                 __func__, err, data[0], data[1]);
125                         return -EIO;
126                 }
127         }
128
129         return 0;
130 }
131
132 static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
133 {
134         unsigned char buf;
135         int err;
136
137         err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
138         if (err < 0)
139                 return err;
140
141         if (on)
142                 buf |= PCF8563_BIT_AIE;
143         else
144                 buf &= ~PCF8563_BIT_AIE;
145
146         buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
147
148         err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
149         if (err < 0) {
150                 dev_err(&client->dev, "%s: write error\n", __func__);
151                 return -EIO;
152         }
153
154         return 0;
155 }
156
157 static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
158                                   unsigned char *pen)
159 {
160         unsigned char buf;
161         int err;
162
163         err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
164         if (err)
165                 return err;
166
167         if (en)
168                 *en = !!(buf & PCF8563_BIT_AIE);
169         if (pen)
170                 *pen = !!(buf & PCF8563_BIT_AF);
171
172         return 0;
173 }
174
175 static irqreturn_t pcf8563_irq(int irq, void *dev_id)
176 {
177         struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
178         int err;
179         char pending;
180
181         err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
182         if (err)
183                 return IRQ_NONE;
184
185         if (pending) {
186                 rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
187                 pcf8563_set_alarm_mode(pcf8563->client, 1);
188                 return IRQ_HANDLED;
189         }
190
191         return IRQ_NONE;
192 }
193
194 /*
195  * In the routines that deal directly with the pcf8563 hardware, we use
196  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
197  */
198 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
199 {
200         struct i2c_client *client = to_i2c_client(dev);
201         struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
202         unsigned char buf[9];
203         int err;
204
205         err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
206         if (err)
207                 return err;
208
209         if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
210                 dev_err(&client->dev,
211                         "low voltage detected, date/time is not reliable.\n");
212                 return -EINVAL;
213         }
214
215         dev_dbg(&client->dev,
216                 "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
217                 "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
218                 __func__,
219                 buf[0], buf[1], buf[2], buf[3],
220                 buf[4], buf[5], buf[6], buf[7],
221                 buf[8]);
222
223
224         tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
225         tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
226         tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
227         tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
228         tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
229         tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
230         tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100;
231         /* detect the polarity heuristically. see note above. */
232         pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
233                 (tm->tm_year >= 100) : (tm->tm_year < 100);
234
235         dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
236                 "mday=%d, mon=%d, year=%d, wday=%d\n",
237                 __func__,
238                 tm->tm_sec, tm->tm_min, tm->tm_hour,
239                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
240
241         return 0;
242 }
243
244 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
245 {
246         struct i2c_client *client = to_i2c_client(dev);
247         struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
248         unsigned char buf[9];
249
250         dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
251                 "mday=%d, mon=%d, year=%d, wday=%d\n",
252                 __func__,
253                 tm->tm_sec, tm->tm_min, tm->tm_hour,
254                 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
255
256         /* hours, minutes and seconds */
257         buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
258         buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
259         buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
260
261         buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
262
263         /* month, 1 - 12 */
264         buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
265
266         /* year and century */
267         buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100);
268         if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
269                 buf[PCF8563_REG_MO] |= PCF8563_MO_C;
270
271         buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
272
273         return pcf8563_write_block_data(client, PCF8563_REG_SC,
274                                 9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
275 }
276
277 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
278 {
279         struct i2c_client *client = to_i2c_client(dev);
280         int ret;
281
282         switch (cmd) {
283         case RTC_VL_READ:
284                 ret = i2c_smbus_read_byte_data(client, PCF8563_REG_SC);
285                 if (ret < 0)
286                         return ret;
287
288                 return put_user(ret & PCF8563_SC_LV ? RTC_VL_DATA_INVALID : 0,
289                                 (unsigned int __user *)arg);
290         default:
291                 return -ENOIOCTLCMD;
292         }
293 }
294
295 static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
296 {
297         struct i2c_client *client = to_i2c_client(dev);
298         unsigned char buf[4];
299         int err;
300
301         err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
302         if (err)
303                 return err;
304
305         dev_dbg(&client->dev,
306                 "%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
307                 __func__, buf[0], buf[1], buf[2], buf[3]);
308
309         tm->time.tm_sec = 0;
310         tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
311         tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
312         tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
313         tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
314
315         err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
316         if (err < 0)
317                 return err;
318
319         dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
320                 " enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
321                 tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
322                 tm->enabled, tm->pending);
323
324         return 0;
325 }
326
327 static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
328 {
329         struct i2c_client *client = to_i2c_client(dev);
330         unsigned char buf[4];
331         int err;
332
333         /* The alarm has no seconds, round up to nearest minute */
334         if (tm->time.tm_sec) {
335                 time64_t alarm_time = rtc_tm_to_time64(&tm->time);
336
337                 alarm_time += 60 - tm->time.tm_sec;
338                 rtc_time64_to_tm(alarm_time, &tm->time);
339         }
340
341         dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
342                 "enabled=%d pending=%d\n", __func__,
343                 tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
344                 tm->time.tm_mday, tm->enabled, tm->pending);
345
346         buf[0] = bin2bcd(tm->time.tm_min);
347         buf[1] = bin2bcd(tm->time.tm_hour);
348         buf[2] = bin2bcd(tm->time.tm_mday);
349         buf[3] = tm->time.tm_wday & 0x07;
350
351         err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
352         if (err)
353                 return err;
354
355         return pcf8563_set_alarm_mode(client, !!tm->enabled);
356 }
357
358 static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
359 {
360         dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
361         return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
362 }
363
364 #ifdef CONFIG_COMMON_CLK
365 /*
366  * Handling of the clkout
367  */
368
369 #define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
370
371 static const int clkout_rates[] = {
372         32768,
373         1024,
374         32,
375         1,
376 };
377
378 static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
379                                                 unsigned long parent_rate)
380 {
381         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
382         struct i2c_client *client = pcf8563->client;
383         unsigned char buf;
384         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
385
386         if (ret < 0)
387                 return 0;
388
389         buf &= PCF8563_REG_CLKO_F_MASK;
390         return clkout_rates[buf];
391 }
392
393 static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
394                                       unsigned long *prate)
395 {
396         int i;
397
398         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
399                 if (clkout_rates[i] <= rate)
400                         return clkout_rates[i];
401
402         return 0;
403 }
404
405 static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
406                                    unsigned long parent_rate)
407 {
408         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
409         struct i2c_client *client = pcf8563->client;
410         unsigned char buf;
411         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
412         int i;
413
414         if (ret < 0)
415                 return ret;
416
417         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
418                 if (clkout_rates[i] == rate) {
419                         buf &= ~PCF8563_REG_CLKO_F_MASK;
420                         buf |= i;
421                         ret = pcf8563_write_block_data(client,
422                                                        PCF8563_REG_CLKO, 1,
423                                                        &buf);
424                         return ret;
425                 }
426
427         return -EINVAL;
428 }
429
430 static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
431 {
432         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
433         struct i2c_client *client = pcf8563->client;
434         unsigned char buf;
435         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
436
437         if (ret < 0)
438                 return ret;
439
440         if (enable)
441                 buf |= PCF8563_REG_CLKO_FE;
442         else
443                 buf &= ~PCF8563_REG_CLKO_FE;
444
445         ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
446         return ret;
447 }
448
449 static int pcf8563_clkout_prepare(struct clk_hw *hw)
450 {
451         return pcf8563_clkout_control(hw, 1);
452 }
453
454 static void pcf8563_clkout_unprepare(struct clk_hw *hw)
455 {
456         pcf8563_clkout_control(hw, 0);
457 }
458
459 static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
460 {
461         struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
462         struct i2c_client *client = pcf8563->client;
463         unsigned char buf;
464         int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
465
466         if (ret < 0)
467                 return ret;
468
469         return !!(buf & PCF8563_REG_CLKO_FE);
470 }
471
472 static const struct clk_ops pcf8563_clkout_ops = {
473         .prepare = pcf8563_clkout_prepare,
474         .unprepare = pcf8563_clkout_unprepare,
475         .is_prepared = pcf8563_clkout_is_prepared,
476         .recalc_rate = pcf8563_clkout_recalc_rate,
477         .round_rate = pcf8563_clkout_round_rate,
478         .set_rate = pcf8563_clkout_set_rate,
479 };
480
481 static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
482 {
483         struct i2c_client *client = pcf8563->client;
484         struct device_node *node = client->dev.of_node;
485         struct clk *clk;
486         struct clk_init_data init;
487         int ret;
488         unsigned char buf;
489
490         /* disable the clkout output */
491         buf = 0;
492         ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
493         if (ret < 0)
494                 return ERR_PTR(ret);
495
496         init.name = "pcf8563-clkout";
497         init.ops = &pcf8563_clkout_ops;
498         init.flags = 0;
499         init.parent_names = NULL;
500         init.num_parents = 0;
501         pcf8563->clkout_hw.init = &init;
502
503         /* optional override of the clockname */
504         of_property_read_string(node, "clock-output-names", &init.name);
505
506         /* register the clock */
507         clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
508
509         if (!IS_ERR(clk))
510                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
511
512         return clk;
513 }
514 #endif
515
516 static const struct rtc_class_ops pcf8563_rtc_ops = {
517         .ioctl          = pcf8563_rtc_ioctl,
518         .read_time      = pcf8563_rtc_read_time,
519         .set_time       = pcf8563_rtc_set_time,
520         .read_alarm     = pcf8563_rtc_read_alarm,
521         .set_alarm      = pcf8563_rtc_set_alarm,
522         .alarm_irq_enable = pcf8563_irq_enable,
523 };
524
525 static int pcf8563_probe(struct i2c_client *client,
526                                 const struct i2c_device_id *id)
527 {
528         struct pcf8563 *pcf8563;
529         int err;
530         unsigned char buf;
531
532         dev_dbg(&client->dev, "%s\n", __func__);
533
534         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
535                 return -ENODEV;
536
537         pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
538                                 GFP_KERNEL);
539         if (!pcf8563)
540                 return -ENOMEM;
541
542         i2c_set_clientdata(client, pcf8563);
543         pcf8563->client = client;
544         device_set_wakeup_capable(&client->dev, 1);
545
546         /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
547         buf = PCF8563_TMRC_1_60;
548         err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
549         if (err < 0) {
550                 dev_err(&client->dev, "%s: write error\n", __func__);
551                 return err;
552         }
553
554         /* Clear flags and disable interrupts */
555         buf = 0;
556         err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
557         if (err < 0) {
558                 dev_err(&client->dev, "%s: write error\n", __func__);
559                 return err;
560         }
561
562         pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
563         if (IS_ERR(pcf8563->rtc))
564                 return PTR_ERR(pcf8563->rtc);
565
566         pcf8563->rtc->ops = &pcf8563_rtc_ops;
567         /* the pcf8563 alarm only supports a minute accuracy */
568         pcf8563->rtc->uie_unsupported = 1;
569         pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
570         pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
571         pcf8563->rtc->set_start_time = true;
572
573         if (client->irq > 0) {
574                 err = devm_request_threaded_irq(&client->dev, client->irq,
575                                 NULL, pcf8563_irq,
576                                 IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
577                                 pcf8563_driver.driver.name, client);
578                 if (err) {
579                         dev_err(&client->dev, "unable to request IRQ %d\n",
580                                                                 client->irq);
581                         return err;
582                 }
583         }
584
585         err = devm_rtc_register_device(pcf8563->rtc);
586         if (err)
587                 return err;
588
589 #ifdef CONFIG_COMMON_CLK
590         /* register clk in common clk framework */
591         pcf8563_clkout_register_clk(pcf8563);
592 #endif
593
594         return 0;
595 }
596
597 static const struct i2c_device_id pcf8563_id[] = {
598         { "pcf8563", 0 },
599         { "rtc8564", 0 },
600         { "pca8565", 0 },
601         { }
602 };
603 MODULE_DEVICE_TABLE(i2c, pcf8563_id);
604
605 #ifdef CONFIG_OF
606 static const struct of_device_id pcf8563_of_match[] = {
607         { .compatible = "nxp,pcf8563" },
608         { .compatible = "epson,rtc8564" },
609         { .compatible = "microcrystal,rv8564" },
610         { .compatible = "nxp,pca8565" },
611         {}
612 };
613 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
614 #endif
615
616 static struct i2c_driver pcf8563_driver = {
617         .driver         = {
618                 .name   = "rtc-pcf8563",
619                 .of_match_table = of_match_ptr(pcf8563_of_match),
620         },
621         .probe          = pcf8563_probe,
622         .id_table       = pcf8563_id,
623 };
624
625 module_i2c_driver(pcf8563_driver);
626
627 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
628 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
629 MODULE_LICENSE("GPL");