Merge tag 'nfs-for-6.5-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[platform/kernel/linux-rpi.git] / drivers / rtc / rtc-nct3018y.c
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2022 Nuvoton Technology Corporation
3
4 #include <linux/bcd.h>
5 #include <linux/clk-provider.h>
6 #include <linux/err.h>
7 #include <linux/i2c.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/rtc.h>
11 #include <linux/slab.h>
12
13 #define NCT3018Y_REG_SC         0x00 /* seconds */
14 #define NCT3018Y_REG_SCA        0x01 /* alarm */
15 #define NCT3018Y_REG_MN         0x02
16 #define NCT3018Y_REG_MNA        0x03 /* alarm */
17 #define NCT3018Y_REG_HR         0x04
18 #define NCT3018Y_REG_HRA        0x05 /* alarm */
19 #define NCT3018Y_REG_DW         0x06
20 #define NCT3018Y_REG_DM         0x07
21 #define NCT3018Y_REG_MO         0x08
22 #define NCT3018Y_REG_YR         0x09
23 #define NCT3018Y_REG_CTRL       0x0A /* timer control */
24 #define NCT3018Y_REG_ST         0x0B /* status */
25 #define NCT3018Y_REG_CLKO       0x0C /* clock out */
26
27 #define NCT3018Y_BIT_AF         BIT(7)
28 #define NCT3018Y_BIT_ST         BIT(7)
29 #define NCT3018Y_BIT_DM         BIT(6)
30 #define NCT3018Y_BIT_HF         BIT(5)
31 #define NCT3018Y_BIT_DSM        BIT(4)
32 #define NCT3018Y_BIT_AIE        BIT(3)
33 #define NCT3018Y_BIT_OFIE       BIT(2)
34 #define NCT3018Y_BIT_CIE        BIT(1)
35 #define NCT3018Y_BIT_TWO        BIT(0)
36
37 #define NCT3018Y_REG_BAT_MASK           0x07
38 #define NCT3018Y_REG_CLKO_F_MASK        0x03 /* frequenc mask */
39 #define NCT3018Y_REG_CLKO_CKE           0x80 /* clock out enabled */
40
41 struct nct3018y {
42         struct rtc_device *rtc;
43         struct i2c_client *client;
44 #ifdef CONFIG_COMMON_CLK
45         struct clk_hw clkout_hw;
46 #endif
47 };
48
49 static int nct3018y_set_alarm_mode(struct i2c_client *client, bool on)
50 {
51         int err, flags;
52
53         dev_dbg(&client->dev, "%s:on:%d\n", __func__, on);
54
55         flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
56         if (flags < 0) {
57                 dev_dbg(&client->dev,
58                         "Failed to read NCT3018Y_REG_CTRL\n");
59                 return flags;
60         }
61
62         if (on)
63                 flags |= NCT3018Y_BIT_AIE;
64         else
65                 flags &= ~NCT3018Y_BIT_AIE;
66
67         flags |= NCT3018Y_BIT_CIE;
68         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
69         if (err < 0) {
70                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
71                 return err;
72         }
73
74         flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
75         if (flags < 0) {
76                 dev_dbg(&client->dev,
77                         "Failed to read NCT3018Y_REG_ST\n");
78                 return flags;
79         }
80
81         flags &= ~(NCT3018Y_BIT_AF);
82         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
83         if (err < 0) {
84                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_ST\n");
85                 return err;
86         }
87
88         return 0;
89 }
90
91 static int nct3018y_get_alarm_mode(struct i2c_client *client, unsigned char *alarm_enable,
92                                    unsigned char *alarm_flag)
93 {
94         int flags;
95
96         if (alarm_enable) {
97                 dev_dbg(&client->dev, "%s:NCT3018Y_REG_CTRL\n", __func__);
98                 flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
99                 if (flags < 0)
100                         return flags;
101                 *alarm_enable = flags & NCT3018Y_BIT_AIE;
102         }
103
104         if (alarm_flag) {
105                 dev_dbg(&client->dev, "%s:NCT3018Y_REG_ST\n", __func__);
106                 flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
107                 if (flags < 0)
108                         return flags;
109                 *alarm_flag = flags & NCT3018Y_BIT_AF;
110         }
111
112         dev_dbg(&client->dev, "%s:alarm_enable:%x alarm_flag:%x\n",
113                 __func__, *alarm_enable, *alarm_flag);
114
115         return 0;
116 }
117
118 static irqreturn_t nct3018y_irq(int irq, void *dev_id)
119 {
120         struct nct3018y *nct3018y = i2c_get_clientdata(dev_id);
121         struct i2c_client *client = nct3018y->client;
122         int err;
123         unsigned char alarm_flag;
124         unsigned char alarm_enable;
125
126         dev_dbg(&client->dev, "%s:irq:%d\n", __func__, irq);
127         err = nct3018y_get_alarm_mode(nct3018y->client, &alarm_enable, &alarm_flag);
128         if (err)
129                 return IRQ_NONE;
130
131         if (alarm_flag) {
132                 dev_dbg(&client->dev, "%s:alarm flag:%x\n",
133                         __func__, alarm_flag);
134                 rtc_update_irq(nct3018y->rtc, 1, RTC_IRQF | RTC_AF);
135                 nct3018y_set_alarm_mode(nct3018y->client, 0);
136                 dev_dbg(&client->dev, "%s:IRQ_HANDLED\n", __func__);
137                 return IRQ_HANDLED;
138         }
139
140         return IRQ_NONE;
141 }
142
143 /*
144  * In the routines that deal directly with the nct3018y hardware, we use
145  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
146  */
147 static int nct3018y_rtc_read_time(struct device *dev, struct rtc_time *tm)
148 {
149         struct i2c_client *client = to_i2c_client(dev);
150         unsigned char buf[10];
151         int err;
152
153         err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_ST, 1, buf);
154         if (err < 0)
155                 return err;
156
157         if (!buf[0]) {
158                 dev_dbg(&client->dev, " voltage <=1.7, date/time is not reliable.\n");
159                 return -EINVAL;
160         }
161
162         err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SC, sizeof(buf), buf);
163         if (err < 0)
164                 return err;
165
166         tm->tm_sec = bcd2bin(buf[0] & 0x7F);
167         tm->tm_min = bcd2bin(buf[2] & 0x7F);
168         tm->tm_hour = bcd2bin(buf[4] & 0x3F);
169         tm->tm_wday = buf[6] & 0x07;
170         tm->tm_mday = bcd2bin(buf[7] & 0x3F);
171         tm->tm_mon = bcd2bin(buf[8] & 0x1F) - 1;
172         tm->tm_year = bcd2bin(buf[9]) + 100;
173
174         return 0;
175 }
176
177 static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
178 {
179         struct i2c_client *client = to_i2c_client(dev);
180         unsigned char buf[4] = {0};
181         int err;
182
183         buf[0] = bin2bcd(tm->tm_sec);
184         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SC, buf[0]);
185         if (err < 0) {
186                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SC\n");
187                 return err;
188         }
189
190         buf[0] = bin2bcd(tm->tm_min);
191         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MN, buf[0]);
192         if (err < 0) {
193                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MN\n");
194                 return err;
195         }
196
197         buf[0] = bin2bcd(tm->tm_hour);
198         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HR, buf[0]);
199         if (err < 0) {
200                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HR\n");
201                 return err;
202         }
203
204         buf[0] = tm->tm_wday & 0x07;
205         buf[1] = bin2bcd(tm->tm_mday);
206         buf[2] = bin2bcd(tm->tm_mon + 1);
207         buf[3] = bin2bcd(tm->tm_year - 100);
208         err = i2c_smbus_write_i2c_block_data(client, NCT3018Y_REG_DW,
209                                              sizeof(buf), buf);
210         if (err < 0) {
211                 dev_dbg(&client->dev, "Unable to write for day and mon and year\n");
212                 return -EIO;
213         }
214
215         return err;
216 }
217
218 static int nct3018y_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
219 {
220         struct i2c_client *client = to_i2c_client(dev);
221         unsigned char buf[5];
222         int err;
223
224         err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SCA,
225                                             sizeof(buf), buf);
226         if (err < 0) {
227                 dev_dbg(&client->dev, "Unable to read date\n");
228                 return -EIO;
229         }
230
231         dev_dbg(&client->dev, "%s: raw data is sec=%02x, min=%02x hr=%02x\n",
232                 __func__, buf[0], buf[2], buf[4]);
233
234         tm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
235         tm->time.tm_min = bcd2bin(buf[2] & 0x7F);
236         tm->time.tm_hour = bcd2bin(buf[4] & 0x3F);
237
238         err = nct3018y_get_alarm_mode(client, &tm->enabled, &tm->pending);
239         if (err < 0)
240                 return err;
241
242         dev_dbg(&client->dev, "%s:s=%d m=%d, hr=%d, enabled=%d, pending=%d\n",
243                 __func__, tm->time.tm_sec, tm->time.tm_min,
244                 tm->time.tm_hour, tm->enabled, tm->pending);
245
246         return 0;
247 }
248
249 static int nct3018y_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
250 {
251         struct i2c_client *client = to_i2c_client(dev);
252         int err;
253
254         dev_dbg(dev, "%s, sec=%d, min=%d hour=%d tm->enabled:%d\n",
255                 __func__, tm->time.tm_sec, tm->time.tm_min, tm->time.tm_hour,
256                 tm->enabled);
257
258         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SCA, bin2bcd(tm->time.tm_sec));
259         if (err < 0) {
260                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SCA\n");
261                 return err;
262         }
263
264         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MNA, bin2bcd(tm->time.tm_min));
265         if (err < 0) {
266                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MNA\n");
267                 return err;
268         }
269
270         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HRA, bin2bcd(tm->time.tm_hour));
271         if (err < 0) {
272                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HRA\n");
273                 return err;
274         }
275
276         return nct3018y_set_alarm_mode(client, tm->enabled);
277 }
278
279 static int nct3018y_irq_enable(struct device *dev, unsigned int enabled)
280 {
281         dev_dbg(dev, "%s: alarm enable=%d\n", __func__, enabled);
282
283         return nct3018y_set_alarm_mode(to_i2c_client(dev), enabled);
284 }
285
286 static int nct3018y_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
287 {
288         struct i2c_client *client = to_i2c_client(dev);
289         int status, flags = 0;
290
291         switch (cmd) {
292         case RTC_VL_READ:
293                 status = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
294                 if (status < 0)
295                         return status;
296
297                 if (!(status & NCT3018Y_REG_BAT_MASK))
298                         flags |= RTC_VL_DATA_INVALID;
299
300                 return put_user(flags, (unsigned int __user *)arg);
301
302         default:
303                 return -ENOIOCTLCMD;
304         }
305 }
306
307 #ifdef CONFIG_COMMON_CLK
308 /*
309  * Handling of the clkout
310  */
311
312 #define clkout_hw_to_nct3018y(_hw) container_of(_hw, struct nct3018y, clkout_hw)
313
314 static const int clkout_rates[] = {
315         32768,
316         1024,
317         32,
318         1,
319 };
320
321 static unsigned long nct3018y_clkout_recalc_rate(struct clk_hw *hw,
322                                                  unsigned long parent_rate)
323 {
324         struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
325         struct i2c_client *client = nct3018y->client;
326         int flags;
327
328         flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
329         if (flags < 0)
330                 return 0;
331
332         flags &= NCT3018Y_REG_CLKO_F_MASK;
333         return clkout_rates[flags];
334 }
335
336 static long nct3018y_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
337                                        unsigned long *prate)
338 {
339         int i;
340
341         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
342                 if (clkout_rates[i] <= rate)
343                         return clkout_rates[i];
344
345         return 0;
346 }
347
348 static int nct3018y_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
349                                     unsigned long parent_rate)
350 {
351         struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
352         struct i2c_client *client = nct3018y->client;
353         int i, flags;
354
355         flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
356         if (flags < 0)
357                 return flags;
358
359         for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
360                 if (clkout_rates[i] == rate) {
361                         flags &= ~NCT3018Y_REG_CLKO_F_MASK;
362                         flags |= i;
363                         return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
364                 }
365
366         return -EINVAL;
367 }
368
369 static int nct3018y_clkout_control(struct clk_hw *hw, bool enable)
370 {
371         struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
372         struct i2c_client *client = nct3018y->client;
373         int flags;
374
375         flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
376         if (flags < 0)
377                 return flags;
378
379         if (enable)
380                 flags |= NCT3018Y_REG_CLKO_CKE;
381         else
382                 flags &= ~NCT3018Y_REG_CLKO_CKE;
383
384         return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
385 }
386
387 static int nct3018y_clkout_prepare(struct clk_hw *hw)
388 {
389         return nct3018y_clkout_control(hw, 1);
390 }
391
392 static void nct3018y_clkout_unprepare(struct clk_hw *hw)
393 {
394         nct3018y_clkout_control(hw, 0);
395 }
396
397 static int nct3018y_clkout_is_prepared(struct clk_hw *hw)
398 {
399         struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
400         struct i2c_client *client = nct3018y->client;
401         int flags;
402
403         flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
404         if (flags < 0)
405                 return flags;
406
407         return flags & NCT3018Y_REG_CLKO_CKE;
408 }
409
410 static const struct clk_ops nct3018y_clkout_ops = {
411         .prepare = nct3018y_clkout_prepare,
412         .unprepare = nct3018y_clkout_unprepare,
413         .is_prepared = nct3018y_clkout_is_prepared,
414         .recalc_rate = nct3018y_clkout_recalc_rate,
415         .round_rate = nct3018y_clkout_round_rate,
416         .set_rate = nct3018y_clkout_set_rate,
417 };
418
419 static struct clk *nct3018y_clkout_register_clk(struct nct3018y *nct3018y)
420 {
421         struct i2c_client *client = nct3018y->client;
422         struct device_node *node = client->dev.of_node;
423         struct clk *clk;
424         struct clk_init_data init;
425
426         init.name = "nct3018y-clkout";
427         init.ops = &nct3018y_clkout_ops;
428         init.flags = 0;
429         init.parent_names = NULL;
430         init.num_parents = 0;
431         nct3018y->clkout_hw.init = &init;
432
433         /* optional override of the clockname */
434         of_property_read_string(node, "clock-output-names", &init.name);
435
436         /* register the clock */
437         clk = devm_clk_register(&client->dev, &nct3018y->clkout_hw);
438
439         if (!IS_ERR(clk))
440                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
441
442         return clk;
443 }
444 #endif
445
446 static const struct rtc_class_ops nct3018y_rtc_ops = {
447         .read_time      = nct3018y_rtc_read_time,
448         .set_time       = nct3018y_rtc_set_time,
449         .read_alarm     = nct3018y_rtc_read_alarm,
450         .set_alarm      = nct3018y_rtc_set_alarm,
451         .alarm_irq_enable = nct3018y_irq_enable,
452         .ioctl          = nct3018y_ioctl,
453 };
454
455 static int nct3018y_probe(struct i2c_client *client)
456 {
457         struct nct3018y *nct3018y;
458         int err, flags;
459
460         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
461                                      I2C_FUNC_SMBUS_BYTE |
462                                      I2C_FUNC_SMBUS_BLOCK_DATA))
463                 return -ENODEV;
464
465         nct3018y = devm_kzalloc(&client->dev, sizeof(struct nct3018y),
466                                 GFP_KERNEL);
467         if (!nct3018y)
468                 return -ENOMEM;
469
470         i2c_set_clientdata(client, nct3018y);
471         nct3018y->client = client;
472         device_set_wakeup_capable(&client->dev, 1);
473
474         flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
475         if (flags < 0) {
476                 dev_dbg(&client->dev, "%s: read error\n", __func__);
477                 return flags;
478         } else if (flags & NCT3018Y_BIT_TWO) {
479                 dev_dbg(&client->dev, "%s: NCT3018Y_BIT_TWO is set\n", __func__);
480         }
481
482         flags = NCT3018Y_BIT_TWO;
483         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
484         if (err < 0) {
485                 dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
486                 return err;
487         }
488
489         flags = 0;
490         err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
491         if (err < 0) {
492                 dev_dbg(&client->dev, "%s: write error\n", __func__);
493                 return err;
494         }
495
496         nct3018y->rtc = devm_rtc_allocate_device(&client->dev);
497         if (IS_ERR(nct3018y->rtc))
498                 return PTR_ERR(nct3018y->rtc);
499
500         nct3018y->rtc->ops = &nct3018y_rtc_ops;
501         nct3018y->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
502         nct3018y->rtc->range_max = RTC_TIMESTAMP_END_2099;
503
504         if (client->irq > 0) {
505                 err = devm_request_threaded_irq(&client->dev, client->irq,
506                                                 NULL, nct3018y_irq,
507                                                 IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
508                                                 "nct3018y", client);
509                 if (err) {
510                         dev_dbg(&client->dev, "unable to request IRQ %d\n", client->irq);
511                         return err;
512                 }
513         } else {
514                 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, nct3018y->rtc->features);
515                 clear_bit(RTC_FEATURE_ALARM, nct3018y->rtc->features);
516         }
517
518 #ifdef CONFIG_COMMON_CLK
519         /* register clk in common clk framework */
520         nct3018y_clkout_register_clk(nct3018y);
521 #endif
522
523         return devm_rtc_register_device(nct3018y->rtc);
524 }
525
526 static const struct i2c_device_id nct3018y_id[] = {
527         { "nct3018y", 0 },
528         { }
529 };
530 MODULE_DEVICE_TABLE(i2c, nct3018y_id);
531
532 static const struct of_device_id nct3018y_of_match[] = {
533         { .compatible = "nuvoton,nct3018y" },
534         {}
535 };
536 MODULE_DEVICE_TABLE(of, nct3018y_of_match);
537
538 static struct i2c_driver nct3018y_driver = {
539         .driver         = {
540                 .name   = "rtc-nct3018y",
541                 .of_match_table = of_match_ptr(nct3018y_of_match),
542         },
543         .probe          = nct3018y_probe,
544         .id_table       = nct3018y_id,
545 };
546
547 module_i2c_driver(nct3018y_driver);
548
549 MODULE_AUTHOR("Medad CChien <ctcchien@nuvoton.com>");
550 MODULE_AUTHOR("Mia Lin <mimi05633@gmail.com>");
551 MODULE_DESCRIPTION("Nuvoton NCT3018Y RTC driver");
552 MODULE_LICENSE("GPL");