summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-nct3018y.c
blob: d43acd3920ed38bf700b7746c35e57b2be38270b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2022 Nuvoton Technology Corporation

#include <linux/bcd.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/rtc.h>
#include <linux/slab.h>

#define NCT3018Y_REG_SC		0x00 /* seconds */
#define NCT3018Y_REG_SCA	0x01 /* alarm */
#define NCT3018Y_REG_MN		0x02
#define NCT3018Y_REG_MNA	0x03 /* alarm */
#define NCT3018Y_REG_HR		0x04
#define NCT3018Y_REG_HRA	0x05 /* alarm */
#define NCT3018Y_REG_DW		0x06
#define NCT3018Y_REG_DM		0x07
#define NCT3018Y_REG_MO		0x08
#define NCT3018Y_REG_YR		0x09
#define NCT3018Y_REG_CTRL	0x0A /* timer control */
#define NCT3018Y_REG_ST		0x0B /* status */
#define NCT3018Y_REG_CLKO	0x0C /* clock out */

#define NCT3018Y_BIT_AF		BIT(7)
#define NCT3018Y_BIT_ST		BIT(7)
#define NCT3018Y_BIT_DM		BIT(6)
#define NCT3018Y_BIT_HF		BIT(5)
#define NCT3018Y_BIT_DSM	BIT(4)
#define NCT3018Y_BIT_AIE	BIT(3)
#define NCT3018Y_BIT_OFIE	BIT(2)
#define NCT3018Y_BIT_CIE	BIT(1)
#define NCT3018Y_BIT_TWO	BIT(0)

#define NCT3018Y_REG_BAT_MASK		0x07
#define NCT3018Y_REG_CLKO_F_MASK	0x03 /* frequenc mask */
#define NCT3018Y_REG_CLKO_CKE		0x80 /* clock out enabled */

struct nct3018y {
	struct rtc_device *rtc;
	struct i2c_client *client;
#ifdef CONFIG_COMMON_CLK
	struct clk_hw clkout_hw;
#endif
};

static int nct3018y_set_alarm_mode(struct i2c_client *client, bool on)
{
	int err, flags;

	dev_dbg(&client->dev, "%s:on:%d\n", __func__, on);

	flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
	if (flags < 0) {
		dev_dbg(&client->dev,
			"Failed to read NCT3018Y_REG_CTRL\n");
		return flags;
	}

	if (on)
		flags |= NCT3018Y_BIT_AIE;
	else
		flags &= ~NCT3018Y_BIT_AIE;

	flags |= NCT3018Y_BIT_CIE;
	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
		return err;
	}

	flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
	if (flags < 0) {
		dev_dbg(&client->dev,
			"Failed to read NCT3018Y_REG_ST\n");
		return flags;
	}

	flags &= ~(NCT3018Y_BIT_AF);
	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_ST\n");
		return err;
	}

	return 0;
}

static int nct3018y_get_alarm_mode(struct i2c_client *client, unsigned char *alarm_enable,
				   unsigned char *alarm_flag)
{
	int flags;

	if (alarm_enable) {
		dev_dbg(&client->dev, "%s:NCT3018Y_REG_CTRL\n", __func__);
		flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
		if (flags < 0)
			return flags;
		*alarm_enable = flags & NCT3018Y_BIT_AIE;
	}

	if (alarm_flag) {
		dev_dbg(&client->dev, "%s:NCT3018Y_REG_ST\n", __func__);
		flags =  i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
		if (flags < 0)
			return flags;
		*alarm_flag = flags & NCT3018Y_BIT_AF;
	}

	dev_dbg(&client->dev, "%s:alarm_enable:%x alarm_flag:%x\n",
		__func__, *alarm_enable, *alarm_flag);

	return 0;
}

static irqreturn_t nct3018y_irq(int irq, void *dev_id)
{
	struct nct3018y *nct3018y = i2c_get_clientdata(dev_id);
	struct i2c_client *client = nct3018y->client;
	int err;
	unsigned char alarm_flag;
	unsigned char alarm_enable;

	dev_dbg(&client->dev, "%s:irq:%d\n", __func__, irq);
	err = nct3018y_get_alarm_mode(nct3018y->client, &alarm_enable, &alarm_flag);
	if (err)
		return IRQ_NONE;

	if (alarm_flag) {
		dev_dbg(&client->dev, "%s:alarm flag:%x\n",
			__func__, alarm_flag);
		rtc_update_irq(nct3018y->rtc, 1, RTC_IRQF | RTC_AF);
		nct3018y_set_alarm_mode(nct3018y->client, 0);
		dev_dbg(&client->dev, "%s:IRQ_HANDLED\n", __func__);
		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

/*
 * In the routines that deal directly with the nct3018y hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 */
static int nct3018y_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[10];
	int err;

	err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_ST, 1, buf);
	if (err < 0)
		return err;

	if (!buf[0]) {
		dev_dbg(&client->dev, " voltage <=1.7, date/time is not reliable.\n");
		return -EINVAL;
	}

	err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SC, sizeof(buf), buf);
	if (err < 0)
		return err;

	tm->tm_sec = bcd2bin(buf[0] & 0x7F);
	tm->tm_min = bcd2bin(buf[2] & 0x7F);
	tm->tm_hour = bcd2bin(buf[4] & 0x3F);
	tm->tm_wday = buf[6] & 0x07;
	tm->tm_mday = bcd2bin(buf[7] & 0x3F);
	tm->tm_mon = bcd2bin(buf[8] & 0x1F) - 1;
	tm->tm_year = bcd2bin(buf[9]) + 100;

	return 0;
}

static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[4] = {0};
	int err;

	buf[0] = bin2bcd(tm->tm_sec);
	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SC, buf[0]);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SC\n");
		return err;
	}

	buf[0] = bin2bcd(tm->tm_min);
	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MN, buf[0]);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MN\n");
		return err;
	}

	buf[0] = bin2bcd(tm->tm_hour);
	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HR, buf[0]);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HR\n");
		return err;
	}

	buf[0] = tm->tm_wday & 0x07;
	buf[1] = bin2bcd(tm->tm_mday);
	buf[2] = bin2bcd(tm->tm_mon + 1);
	buf[3] = bin2bcd(tm->tm_year - 100);
	err = i2c_smbus_write_i2c_block_data(client, NCT3018Y_REG_DW,
					     sizeof(buf), buf);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write for day and mon and year\n");
		return -EIO;
	}

	return err;
}

static int nct3018y_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[5];
	int err;

	err = i2c_smbus_read_i2c_block_data(client, NCT3018Y_REG_SCA,
					    sizeof(buf), buf);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to read date\n");
		return -EIO;
	}

	dev_dbg(&client->dev, "%s: raw data is sec=%02x, min=%02x hr=%02x\n",
		__func__, buf[0], buf[2], buf[4]);

	tm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
	tm->time.tm_min = bcd2bin(buf[2] & 0x7F);
	tm->time.tm_hour = bcd2bin(buf[4] & 0x3F);

	err = nct3018y_get_alarm_mode(client, &tm->enabled, &tm->pending);
	if (err < 0)
		return err;

	dev_dbg(&client->dev, "%s:s=%d m=%d, hr=%d, enabled=%d, pending=%d\n",
		__func__, tm->time.tm_sec, tm->time.tm_min,
		tm->time.tm_hour, tm->enabled, tm->pending);

	return 0;
}

static int nct3018y_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	int err;

	dev_dbg(dev, "%s, sec=%d, min=%d hour=%d tm->enabled:%d\n",
		__func__, tm->time.tm_sec, tm->time.tm_min, tm->time.tm_hour,
		tm->enabled);

	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SCA, bin2bcd(tm->time.tm_sec));
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_SCA\n");
		return err;
	}

	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_MNA, bin2bcd(tm->time.tm_min));
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_MNA\n");
		return err;
	}

	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_HRA, bin2bcd(tm->time.tm_hour));
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_HRA\n");
		return err;
	}

	return nct3018y_set_alarm_mode(client, tm->enabled);
}

static int nct3018y_irq_enable(struct device *dev, unsigned int enabled)
{
	dev_dbg(dev, "%s: alarm enable=%d\n", __func__, enabled);

	return nct3018y_set_alarm_mode(to_i2c_client(dev), enabled);
}

static int nct3018y_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
	struct i2c_client *client = to_i2c_client(dev);
	int status, flags = 0;

	switch (cmd) {
	case RTC_VL_READ:
		status = i2c_smbus_read_byte_data(client, NCT3018Y_REG_ST);
		if (status < 0)
			return status;

		if (!(status & NCT3018Y_REG_BAT_MASK))
			flags |= RTC_VL_DATA_INVALID;

		return put_user(flags, (unsigned int __user *)arg);

	default:
		return -ENOIOCTLCMD;
	}
}

#ifdef CONFIG_COMMON_CLK
/*
 * Handling of the clkout
 */

#define clkout_hw_to_nct3018y(_hw) container_of(_hw, struct nct3018y, clkout_hw)

static const int clkout_rates[] = {
	32768,
	1024,
	32,
	1,
};

static unsigned long nct3018y_clkout_recalc_rate(struct clk_hw *hw,
						 unsigned long parent_rate)
{
	struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
	struct i2c_client *client = nct3018y->client;
	int flags;

	flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
	if (flags < 0)
		return 0;

	flags &= NCT3018Y_REG_CLKO_F_MASK;
	return clkout_rates[flags];
}

static long nct3018y_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
				       unsigned long *prate)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
		if (clkout_rates[i] <= rate)
			return clkout_rates[i];

	return 0;
}

static int nct3018y_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
				    unsigned long parent_rate)
{
	struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
	struct i2c_client *client = nct3018y->client;
	int i, flags;

	flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
	if (flags < 0)
		return flags;

	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
		if (clkout_rates[i] == rate) {
			flags &= ~NCT3018Y_REG_CLKO_F_MASK;
			flags |= i;
			return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
		}

	return -EINVAL;
}

static int nct3018y_clkout_control(struct clk_hw *hw, bool enable)
{
	struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
	struct i2c_client *client = nct3018y->client;
	int flags;

	flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
	if (flags < 0)
		return flags;

	if (enable)
		flags |= NCT3018Y_REG_CLKO_CKE;
	else
		flags &= ~NCT3018Y_REG_CLKO_CKE;

	return i2c_smbus_write_byte_data(client, NCT3018Y_REG_CLKO, flags);
}

static int nct3018y_clkout_prepare(struct clk_hw *hw)
{
	return nct3018y_clkout_control(hw, 1);
}

static void nct3018y_clkout_unprepare(struct clk_hw *hw)
{
	nct3018y_clkout_control(hw, 0);
}

static int nct3018y_clkout_is_prepared(struct clk_hw *hw)
{
	struct nct3018y *nct3018y = clkout_hw_to_nct3018y(hw);
	struct i2c_client *client = nct3018y->client;
	int flags;

	flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CLKO);
	if (flags < 0)
		return flags;

	return flags & NCT3018Y_REG_CLKO_CKE;
}

static const struct clk_ops nct3018y_clkout_ops = {
	.prepare = nct3018y_clkout_prepare,
	.unprepare = nct3018y_clkout_unprepare,
	.is_prepared = nct3018y_clkout_is_prepared,
	.recalc_rate = nct3018y_clkout_recalc_rate,
	.round_rate = nct3018y_clkout_round_rate,
	.set_rate = nct3018y_clkout_set_rate,
};

static struct clk *nct3018y_clkout_register_clk(struct nct3018y *nct3018y)
{
	struct i2c_client *client = nct3018y->client;
	struct device_node *node = client->dev.of_node;
	struct clk *clk;
	struct clk_init_data init;

	init.name = "nct3018y-clkout";
	init.ops = &nct3018y_clkout_ops;
	init.flags = 0;
	init.parent_names = NULL;
	init.num_parents = 0;
	nct3018y->clkout_hw.init = &init;

	/* optional override of the clockname */
	of_property_read_string(node, "clock-output-names", &init.name);

	/* register the clock */
	clk = devm_clk_register(&client->dev, &nct3018y->clkout_hw);

	if (!IS_ERR(clk))
		of_clk_add_provider(node, of_clk_src_simple_get, clk);

	return clk;
}
#endif

static const struct rtc_class_ops nct3018y_rtc_ops = {
	.read_time	= nct3018y_rtc_read_time,
	.set_time	= nct3018y_rtc_set_time,
	.read_alarm	= nct3018y_rtc_read_alarm,
	.set_alarm	= nct3018y_rtc_set_alarm,
	.alarm_irq_enable = nct3018y_irq_enable,
	.ioctl		= nct3018y_ioctl,
};

static int nct3018y_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct nct3018y *nct3018y;
	int err, flags;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
				     I2C_FUNC_SMBUS_BYTE |
				     I2C_FUNC_SMBUS_BLOCK_DATA))
		return -ENODEV;

	nct3018y = devm_kzalloc(&client->dev, sizeof(struct nct3018y),
				GFP_KERNEL);
	if (!nct3018y)
		return -ENOMEM;

	i2c_set_clientdata(client, nct3018y);
	nct3018y->client = client;
	device_set_wakeup_capable(&client->dev, 1);

	flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
	if (flags < 0) {
		dev_dbg(&client->dev, "%s: read error\n", __func__);
		return flags;
	} else if (flags & NCT3018Y_BIT_TWO) {
		dev_dbg(&client->dev, "%s: NCT3018Y_BIT_TWO is set\n", __func__);
	}

	flags = NCT3018Y_BIT_TWO;
	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
	if (err < 0) {
		dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
		return err;
	}

	flags = 0;
	err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_ST, flags);
	if (err < 0) {
		dev_dbg(&client->dev, "%s: write error\n", __func__);
		return err;
	}

	nct3018y->rtc = devm_rtc_allocate_device(&client->dev);
	if (IS_ERR(nct3018y->rtc))
		return PTR_ERR(nct3018y->rtc);

	nct3018y->rtc->ops = &nct3018y_rtc_ops;
	nct3018y->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
	nct3018y->rtc->range_max = RTC_TIMESTAMP_END_2099;

	if (client->irq > 0) {
		err = devm_request_threaded_irq(&client->dev, client->irq,
						NULL, nct3018y_irq,
						IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
						"nct3018y", client);
		if (err) {
			dev_dbg(&client->dev, "unable to request IRQ %d\n", client->irq);
			return err;
		}
	} else {
		clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, nct3018y->rtc->features);
		clear_bit(RTC_FEATURE_ALARM, nct3018y->rtc->features);
	}

#ifdef CONFIG_COMMON_CLK
	/* register clk in common clk framework */
	nct3018y_clkout_register_clk(nct3018y);
#endif

	return devm_rtc_register_device(nct3018y->rtc);
}

static const struct i2c_device_id nct3018y_id[] = {
	{ "nct3018y", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, nct3018y_id);

static const struct of_device_id nct3018y_of_match[] = {
	{ .compatible = "nuvoton,nct3018y" },
	{}
};
MODULE_DEVICE_TABLE(of, nct3018y_of_match);

static struct i2c_driver nct3018y_driver = {
	.driver		= {
		.name	= "rtc-nct3018y",
		.of_match_table = of_match_ptr(nct3018y_of_match),
	},
	.probe		= nct3018y_probe,
	.id_table	= nct3018y_id,
};

module_i2c_driver(nct3018y_driver);

MODULE_AUTHOR("Medad CChien <ctcchien@nuvoton.com>");
MODULE_AUTHOR("Mia Lin <mimi05633@gmail.com>");
MODULE_DESCRIPTION("Nuvoton NCT3018Y RTC driver");
MODULE_LICENSE("GPL");