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
 60static struct i2c_driver pcf8563_driver;
 61
 62struct 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
 86static 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
111static 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
132static 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
157static 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
175static 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 */
198static 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
244static 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
 
277static 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
295static 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
327static 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	buf[0] = bin2bcd(tm->time.tm_min);
334	buf[1] = bin2bcd(tm->time.tm_hour);
335	buf[2] = bin2bcd(tm->time.tm_mday);
336	buf[3] = tm->time.tm_wday & 0x07;
337
338	err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
339	if (err)
340		return err;
341
342	return pcf8563_set_alarm_mode(client, !!tm->enabled);
343}
344
345static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
346{
347	dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
348	return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
349}
350
351#ifdef CONFIG_COMMON_CLK
352/*
353 * Handling of the clkout
354 */
355
356#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
357
358static const int clkout_rates[] = {
359	32768,
360	1024,
361	32,
362	1,
363};
364
365static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
366						unsigned long parent_rate)
367{
368	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
369	struct i2c_client *client = pcf8563->client;
370	unsigned char buf;
371	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
372
373	if (ret < 0)
374		return 0;
375
376	buf &= PCF8563_REG_CLKO_F_MASK;
377	return clkout_rates[buf];
378}
379
380static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
381				      unsigned long *prate)
382{
383	int i;
384
385	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
386		if (clkout_rates[i] <= rate)
387			return clkout_rates[i];
388
389	return 0;
390}
391
392static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
393				   unsigned long parent_rate)
394{
395	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
396	struct i2c_client *client = pcf8563->client;
397	unsigned char buf;
398	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
399	int i;
400
401	if (ret < 0)
402		return ret;
403
404	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
405		if (clkout_rates[i] == rate) {
406			buf &= ~PCF8563_REG_CLKO_F_MASK;
407			buf |= i;
408			ret = pcf8563_write_block_data(client,
409						       PCF8563_REG_CLKO, 1,
410						       &buf);
411			return ret;
412		}
413
414	return -EINVAL;
415}
416
417static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
418{
419	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
420	struct i2c_client *client = pcf8563->client;
421	unsigned char buf;
422	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
423
424	if (ret < 0)
425		return ret;
426
427	if (enable)
428		buf |= PCF8563_REG_CLKO_FE;
429	else
430		buf &= ~PCF8563_REG_CLKO_FE;
431
432	ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
433	return ret;
434}
435
436static int pcf8563_clkout_prepare(struct clk_hw *hw)
437{
438	return pcf8563_clkout_control(hw, 1);
439}
440
441static void pcf8563_clkout_unprepare(struct clk_hw *hw)
442{
443	pcf8563_clkout_control(hw, 0);
444}
445
446static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
447{
448	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
449	struct i2c_client *client = pcf8563->client;
450	unsigned char buf;
451	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
452
453	if (ret < 0)
454		return ret;
455
456	return !!(buf & PCF8563_REG_CLKO_FE);
457}
458
459static const struct clk_ops pcf8563_clkout_ops = {
460	.prepare = pcf8563_clkout_prepare,
461	.unprepare = pcf8563_clkout_unprepare,
462	.is_prepared = pcf8563_clkout_is_prepared,
463	.recalc_rate = pcf8563_clkout_recalc_rate,
464	.round_rate = pcf8563_clkout_round_rate,
465	.set_rate = pcf8563_clkout_set_rate,
466};
467
468static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
469{
470	struct i2c_client *client = pcf8563->client;
471	struct device_node *node = client->dev.of_node;
472	struct clk *clk;
473	struct clk_init_data init;
474	int ret;
475	unsigned char buf;
476
477	/* disable the clkout output */
478	buf = 0;
479	ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
480	if (ret < 0)
481		return ERR_PTR(ret);
482
483	init.name = "pcf8563-clkout";
484	init.ops = &pcf8563_clkout_ops;
485	init.flags = 0;
486	init.parent_names = NULL;
487	init.num_parents = 0;
488	pcf8563->clkout_hw.init = &init;
489
490	/* optional override of the clockname */
491	of_property_read_string(node, "clock-output-names", &init.name);
492
493	/* register the clock */
494	clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
495
496	if (!IS_ERR(clk))
497		of_clk_add_provider(node, of_clk_src_simple_get, clk);
498
499	return clk;
500}
501#endif
502
503static const struct rtc_class_ops pcf8563_rtc_ops = {
504	.ioctl		= pcf8563_rtc_ioctl,
505	.read_time	= pcf8563_rtc_read_time,
506	.set_time	= pcf8563_rtc_set_time,
507	.read_alarm	= pcf8563_rtc_read_alarm,
508	.set_alarm	= pcf8563_rtc_set_alarm,
509	.alarm_irq_enable = pcf8563_irq_enable,
510};
511
512static int pcf8563_probe(struct i2c_client *client)
 
513{
514	struct pcf8563 *pcf8563;
515	int err;
516	unsigned char buf;
517
518	dev_dbg(&client->dev, "%s\n", __func__);
519
520	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
521		return -ENODEV;
522
523	pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
524				GFP_KERNEL);
525	if (!pcf8563)
526		return -ENOMEM;
527
528	i2c_set_clientdata(client, pcf8563);
529	pcf8563->client = client;
530	device_set_wakeup_capable(&client->dev, 1);
531
532	/* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
533	buf = PCF8563_TMRC_1_60;
534	err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
535	if (err < 0) {
536		dev_err(&client->dev, "%s: write error\n", __func__);
537		return err;
538	}
539
540	/* Clear flags and disable interrupts */
541	buf = 0;
542	err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
543	if (err < 0) {
544		dev_err(&client->dev, "%s: write error\n", __func__);
545		return err;
546	}
547
548	pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
549	if (IS_ERR(pcf8563->rtc))
550		return PTR_ERR(pcf8563->rtc);
551
552	pcf8563->rtc->ops = &pcf8563_rtc_ops;
553	/* the pcf8563 alarm only supports a minute accuracy */
554	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, pcf8563->rtc->features);
555	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf8563->rtc->features);
556	pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
557	pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
558	pcf8563->rtc->set_start_time = true;
559
560	if (client->irq > 0) {
561		unsigned long irqflags = IRQF_TRIGGER_LOW;
562
563		if (dev_fwnode(&client->dev))
564			irqflags = 0;
565
566		err = devm_request_threaded_irq(&client->dev, client->irq,
567				NULL, pcf8563_irq,
568				IRQF_SHARED | IRQF_ONESHOT | irqflags,
569				pcf8563_driver.driver.name, client);
570		if (err) {
571			dev_err(&client->dev, "unable to request IRQ %d\n",
572								client->irq);
573			return err;
574		}
575	} else {
576		clear_bit(RTC_FEATURE_ALARM, pcf8563->rtc->features);
577	}
578
579	err = devm_rtc_register_device(pcf8563->rtc);
580	if (err)
581		return err;
582
583#ifdef CONFIG_COMMON_CLK
584	/* register clk in common clk framework */
585	pcf8563_clkout_register_clk(pcf8563);
586#endif
587
588	return 0;
589}
590
591static const struct i2c_device_id pcf8563_id[] = {
592	{ "pcf8563", 0 },
593	{ "rtc8564", 0 },
594	{ "pca8565", 0 },
595	{ }
596};
597MODULE_DEVICE_TABLE(i2c, pcf8563_id);
598
599#ifdef CONFIG_OF
600static const struct of_device_id pcf8563_of_match[] = {
601	{ .compatible = "nxp,pcf8563" },
602	{ .compatible = "epson,rtc8564" },
603	{ .compatible = "microcrystal,rv8564" },
604	{ .compatible = "nxp,pca8565" },
605	{}
606};
607MODULE_DEVICE_TABLE(of, pcf8563_of_match);
608#endif
609
610static struct i2c_driver pcf8563_driver = {
611	.driver		= {
612		.name	= "rtc-pcf8563",
613		.of_match_table = of_match_ptr(pcf8563_of_match),
614	},
615	.probe		= pcf8563_probe,
616	.id_table	= pcf8563_id,
617};
618
619module_i2c_driver(pcf8563_driver);
620
621MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
622MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
623MODULE_LICENSE("GPL");

  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 * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.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		(1 << 1)
 26#define PCF8563_BIT_AF		(1 << 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
 60static struct i2c_driver pcf8563_driver;
 61
 62struct 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	int voltage_low; /* incicates if a low_voltage was detected */
 80
 81	struct i2c_client *client;
 82#ifdef CONFIG_COMMON_CLK
 83	struct clk_hw		clkout_hw;
 84#endif
 85};
 86
 87static int pcf8563_read_block_data(struct i2c_client *client, unsigned char reg,
 88				   unsigned char length, unsigned char *buf)
 89{
 90	struct i2c_msg msgs[] = {
 91		{/* setup read ptr */
 92			.addr = client->addr,
 93			.len = 1,
 94			.buf = &reg,
 95		},
 96		{
 97			.addr = client->addr,
 98			.flags = I2C_M_RD,
 99			.len = length,
100			.buf = buf
101		},
102	};
103
104	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
105		dev_err(&client->dev, "%s: read error\n", __func__);
106		return -EIO;
107	}
108
109	return 0;
110}
111
112static int pcf8563_write_block_data(struct i2c_client *client,
113				   unsigned char reg, unsigned char length,
114				   unsigned char *buf)
115{
116	int i, err;
117
118	for (i = 0; i < length; i++) {
119		unsigned char data[2] = { reg + i, buf[i] };
120
121		err = i2c_master_send(client, data, sizeof(data));
122		if (err != sizeof(data)) {
123			dev_err(&client->dev,
124				"%s: err=%d addr=%02x, data=%02x\n",
125				__func__, err, data[0], data[1]);
126			return -EIO;
127		}
128	}
129
130	return 0;
131}
132
133static int pcf8563_set_alarm_mode(struct i2c_client *client, bool on)
134{
135	unsigned char buf;
136	int err;
137
138	err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
139	if (err < 0)
140		return err;
141
142	if (on)
143		buf |= PCF8563_BIT_AIE;
144	else
145		buf &= ~PCF8563_BIT_AIE;
146
147	buf &= ~(PCF8563_BIT_AF | PCF8563_BITS_ST2_N);
148
149	err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
150	if (err < 0) {
151		dev_err(&client->dev, "%s: write error\n", __func__);
152		return -EIO;
153	}
154
155	return 0;
156}
157
158static int pcf8563_get_alarm_mode(struct i2c_client *client, unsigned char *en,
159				  unsigned char *pen)
160{
161	unsigned char buf;
162	int err;
163
164	err = pcf8563_read_block_data(client, PCF8563_REG_ST2, 1, &buf);
165	if (err)
166		return err;
167
168	if (en)
169		*en = !!(buf & PCF8563_BIT_AIE);
170	if (pen)
171		*pen = !!(buf & PCF8563_BIT_AF);
172
173	return 0;
174}
175
176static irqreturn_t pcf8563_irq(int irq, void *dev_id)
177{
178	struct pcf8563 *pcf8563 = i2c_get_clientdata(dev_id);
179	int err;
180	char pending;
181
182	err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending);
183	if (err)
184		return IRQ_NONE;
185
186	if (pending) {
187		rtc_update_irq(pcf8563->rtc, 1, RTC_IRQF | RTC_AF);
188		pcf8563_set_alarm_mode(pcf8563->client, 1);
189		return IRQ_HANDLED;
190	}
191
192	return IRQ_NONE;
193}
194
195/*
196 * In the routines that deal directly with the pcf8563 hardware, we use
197 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
198 */
199static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
200{
201	struct i2c_client *client = to_i2c_client(dev);
202	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
203	unsigned char buf[9];
204	int err;
205
206	err = pcf8563_read_block_data(client, PCF8563_REG_ST1, 9, buf);
207	if (err)
208		return err;
209
210	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
211		pcf8563->voltage_low = 1;
212		dev_err(&client->dev,
213			"low voltage detected, date/time is not reliable.\n");
214		return -EINVAL;
215	}
216
217	dev_dbg(&client->dev,
218		"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
219		"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
220		__func__,
221		buf[0], buf[1], buf[2], buf[3],
222		buf[4], buf[5], buf[6], buf[7],
223		buf[8]);
224
225
226	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
227	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
228	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
229	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
230	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
231	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
232	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]) + 100;
233	/* detect the polarity heuristically. see note above. */
234	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
235		(tm->tm_year >= 100) : (tm->tm_year < 100);
236
237	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
238		"mday=%d, mon=%d, year=%d, wday=%d\n",
239		__func__,
240		tm->tm_sec, tm->tm_min, tm->tm_hour,
241		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
242
243	return 0;
244}
245
246static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
247{
248	struct i2c_client *client = to_i2c_client(dev);
249	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
250	unsigned char buf[9];
251
252	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
253		"mday=%d, mon=%d, year=%d, wday=%d\n",
254		__func__,
255		tm->tm_sec, tm->tm_min, tm->tm_hour,
256		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
257
258	/* hours, minutes and seconds */
259	buf[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
260	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
261	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);
262
263	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);
264
265	/* month, 1 - 12 */
266	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);
267
268	/* year and century */
269	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year - 100);
270	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
271		buf[PCF8563_REG_MO] |= PCF8563_MO_C;
272
273	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;
274
275	return pcf8563_write_block_data(client, PCF8563_REG_SC,
276				9 - PCF8563_REG_SC, buf + PCF8563_REG_SC);
277}
278
279#ifdef CONFIG_RTC_INTF_DEV
280static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
281{
282	struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
283	struct rtc_time tm;
284
285	switch (cmd) {
286	case RTC_VL_READ:
287		if (pcf8563->voltage_low)
288			dev_info(dev, "low voltage detected, date/time is not reliable.\n");
 
289
290		if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
291					sizeof(int)))
292			return -EFAULT;
293		return 0;
294	case RTC_VL_CLR:
295		/*
296		 * Clear the VL bit in the seconds register in case
297		 * the time has not been set already (which would
298		 * have cleared it). This does not really matter
299		 * because of the cached voltage_low value but do it
300		 * anyway for consistency.
301		 */
302		if (pcf8563_rtc_read_time(dev, &tm))
303			pcf8563_rtc_set_time(dev, &tm);
304
305		/* Clear the cached value. */
306		pcf8563->voltage_low = 0;
307
308		return 0;
309	default:
310		return -ENOIOCTLCMD;
311	}
312}
313#else
314#define pcf8563_rtc_ioctl NULL
315#endif
316
317static int pcf8563_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *tm)
318{
319	struct i2c_client *client = to_i2c_client(dev);
320	unsigned char buf[4];
321	int err;
322
323	err = pcf8563_read_block_data(client, PCF8563_REG_AMN, 4, buf);
324	if (err)
325		return err;
326
327	dev_dbg(&client->dev,
328		"%s: raw data is min=%02x, hr=%02x, mday=%02x, wday=%02x\n",
329		__func__, buf[0], buf[1], buf[2], buf[3]);
330
331	tm->time.tm_sec = 0;
332	tm->time.tm_min = bcd2bin(buf[0] & 0x7F);
333	tm->time.tm_hour = bcd2bin(buf[1] & 0x3F);
334	tm->time.tm_mday = bcd2bin(buf[2] & 0x3F);
335	tm->time.tm_wday = bcd2bin(buf[3] & 0x7);
336
337	err = pcf8563_get_alarm_mode(client, &tm->enabled, &tm->pending);
338	if (err < 0)
339		return err;
340
341	dev_dbg(&client->dev, "%s: tm is mins=%d, hours=%d, mday=%d, wday=%d,"
342		" enabled=%d, pending=%d\n", __func__, tm->time.tm_min,
343		tm->time.tm_hour, tm->time.tm_mday, tm->time.tm_wday,
344		tm->enabled, tm->pending);
345
346	return 0;
347}
348
349static int pcf8563_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *tm)
350{
351	struct i2c_client *client = to_i2c_client(dev);
352	unsigned char buf[4];
353	int err;
354
355	/* The alarm has no seconds, round up to nearest minute */
356	if (tm->time.tm_sec) {
357		time64_t alarm_time = rtc_tm_to_time64(&tm->time);
358
359		alarm_time += 60 - tm->time.tm_sec;
360		rtc_time64_to_tm(alarm_time, &tm->time);
361	}
362
363	dev_dbg(dev, "%s, min=%d hour=%d wday=%d mday=%d "
364		"enabled=%d pending=%d\n", __func__,
365		tm->time.tm_min, tm->time.tm_hour, tm->time.tm_wday,
366		tm->time.tm_mday, tm->enabled, tm->pending);
367
368	buf[0] = bin2bcd(tm->time.tm_min);
369	buf[1] = bin2bcd(tm->time.tm_hour);
370	buf[2] = bin2bcd(tm->time.tm_mday);
371	buf[3] = tm->time.tm_wday & 0x07;
372
373	err = pcf8563_write_block_data(client, PCF8563_REG_AMN, 4, buf);
374	if (err)
375		return err;
376
377	return pcf8563_set_alarm_mode(client, !!tm->enabled);
378}
379
380static int pcf8563_irq_enable(struct device *dev, unsigned int enabled)
381{
382	dev_dbg(dev, "%s: en=%d\n", __func__, enabled);
383	return pcf8563_set_alarm_mode(to_i2c_client(dev), !!enabled);
384}
385
386#ifdef CONFIG_COMMON_CLK
387/*
388 * Handling of the clkout
389 */
390
391#define clkout_hw_to_pcf8563(_hw) container_of(_hw, struct pcf8563, clkout_hw)
392
393static int clkout_rates[] = {
394	32768,
395	1024,
396	32,
397	1,
398};
399
400static unsigned long pcf8563_clkout_recalc_rate(struct clk_hw *hw,
401						unsigned long parent_rate)
402{
403	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
404	struct i2c_client *client = pcf8563->client;
405	unsigned char buf;
406	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
407
408	if (ret < 0)
409		return 0;
410
411	buf &= PCF8563_REG_CLKO_F_MASK;
412	return clkout_rates[buf];
413}
414
415static long pcf8563_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
416				      unsigned long *prate)
417{
418	int i;
419
420	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
421		if (clkout_rates[i] <= rate)
422			return clkout_rates[i];
423
424	return 0;
425}
426
427static int pcf8563_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
428				   unsigned long parent_rate)
429{
430	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
431	struct i2c_client *client = pcf8563->client;
432	unsigned char buf;
433	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
434	int i;
435
436	if (ret < 0)
437		return ret;
438
439	for (i = 0; i < ARRAY_SIZE(clkout_rates); i++)
440		if (clkout_rates[i] == rate) {
441			buf &= ~PCF8563_REG_CLKO_F_MASK;
442			buf |= i;
443			ret = pcf8563_write_block_data(client,
444						       PCF8563_REG_CLKO, 1,
445						       &buf);
446			return ret;
447		}
448
449	return -EINVAL;
450}
451
452static int pcf8563_clkout_control(struct clk_hw *hw, bool enable)
453{
454	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
455	struct i2c_client *client = pcf8563->client;
456	unsigned char buf;
457	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
458
459	if (ret < 0)
460		return ret;
461
462	if (enable)
463		buf |= PCF8563_REG_CLKO_FE;
464	else
465		buf &= ~PCF8563_REG_CLKO_FE;
466
467	ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
468	return ret;
469}
470
471static int pcf8563_clkout_prepare(struct clk_hw *hw)
472{
473	return pcf8563_clkout_control(hw, 1);
474}
475
476static void pcf8563_clkout_unprepare(struct clk_hw *hw)
477{
478	pcf8563_clkout_control(hw, 0);
479}
480
481static int pcf8563_clkout_is_prepared(struct clk_hw *hw)
482{
483	struct pcf8563 *pcf8563 = clkout_hw_to_pcf8563(hw);
484	struct i2c_client *client = pcf8563->client;
485	unsigned char buf;
486	int ret = pcf8563_read_block_data(client, PCF8563_REG_CLKO, 1, &buf);
487
488	if (ret < 0)
489		return ret;
490
491	return !!(buf & PCF8563_REG_CLKO_FE);
492}
493
494static const struct clk_ops pcf8563_clkout_ops = {
495	.prepare = pcf8563_clkout_prepare,
496	.unprepare = pcf8563_clkout_unprepare,
497	.is_prepared = pcf8563_clkout_is_prepared,
498	.recalc_rate = pcf8563_clkout_recalc_rate,
499	.round_rate = pcf8563_clkout_round_rate,
500	.set_rate = pcf8563_clkout_set_rate,
501};
502
503static struct clk *pcf8563_clkout_register_clk(struct pcf8563 *pcf8563)
504{
505	struct i2c_client *client = pcf8563->client;
506	struct device_node *node = client->dev.of_node;
507	struct clk *clk;
508	struct clk_init_data init;
509	int ret;
510	unsigned char buf;
511
512	/* disable the clkout output */
513	buf = 0;
514	ret = pcf8563_write_block_data(client, PCF8563_REG_CLKO, 1, &buf);
515	if (ret < 0)
516		return ERR_PTR(ret);
517
518	init.name = "pcf8563-clkout";
519	init.ops = &pcf8563_clkout_ops;
520	init.flags = 0;
521	init.parent_names = NULL;
522	init.num_parents = 0;
523	pcf8563->clkout_hw.init = &init;
524
525	/* optional override of the clockname */
526	of_property_read_string(node, "clock-output-names", &init.name);
527
528	/* register the clock */
529	clk = devm_clk_register(&client->dev, &pcf8563->clkout_hw);
530
531	if (!IS_ERR(clk))
532		of_clk_add_provider(node, of_clk_src_simple_get, clk);
533
534	return clk;
535}
536#endif
537
538static const struct rtc_class_ops pcf8563_rtc_ops = {
539	.ioctl		= pcf8563_rtc_ioctl,
540	.read_time	= pcf8563_rtc_read_time,
541	.set_time	= pcf8563_rtc_set_time,
542	.read_alarm	= pcf8563_rtc_read_alarm,
543	.set_alarm	= pcf8563_rtc_set_alarm,
544	.alarm_irq_enable = pcf8563_irq_enable,
545};
546
547static int pcf8563_probe(struct i2c_client *client,
548				const struct i2c_device_id *id)
549{
550	struct pcf8563 *pcf8563;
551	int err;
552	unsigned char buf;
553
554	dev_dbg(&client->dev, "%s\n", __func__);
555
556	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
557		return -ENODEV;
558
559	pcf8563 = devm_kzalloc(&client->dev, sizeof(struct pcf8563),
560				GFP_KERNEL);
561	if (!pcf8563)
562		return -ENOMEM;
563
564	i2c_set_clientdata(client, pcf8563);
565	pcf8563->client = client;
566	device_set_wakeup_capable(&client->dev, 1);
567
568	/* Set timer to lowest frequency to save power (ref Haoyu datasheet) */
569	buf = PCF8563_TMRC_1_60;
570	err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf);
571	if (err < 0) {
572		dev_err(&client->dev, "%s: write error\n", __func__);
573		return err;
574	}
575
576	/* Clear flags and disable interrupts */
577	buf = 0;
578	err = pcf8563_write_block_data(client, PCF8563_REG_ST2, 1, &buf);
579	if (err < 0) {
580		dev_err(&client->dev, "%s: write error\n", __func__);
581		return err;
582	}
583
584	pcf8563->rtc = devm_rtc_allocate_device(&client->dev);
585	if (IS_ERR(pcf8563->rtc))
586		return PTR_ERR(pcf8563->rtc);
587
588	pcf8563->rtc->ops = &pcf8563_rtc_ops;
589	/* the pcf8563 alarm only supports a minute accuracy */
590	pcf8563->rtc->uie_unsupported = 1;
 
591	pcf8563->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
592	pcf8563->rtc->range_max = RTC_TIMESTAMP_END_2099;
593	pcf8563->rtc->set_start_time = true;
594
595	if (client->irq > 0) {
 
 
 
 
 
596		err = devm_request_threaded_irq(&client->dev, client->irq,
597				NULL, pcf8563_irq,
598				IRQF_SHARED | IRQF_ONESHOT | IRQF_TRIGGER_LOW,
599				pcf8563_driver.driver.name, client);
600		if (err) {
601			dev_err(&client->dev, "unable to request IRQ %d\n",
602								client->irq);
603			return err;
604		}
 
 
605	}
606
607	err = rtc_register_device(pcf8563->rtc);
608	if (err)
609		return err;
610
611#ifdef CONFIG_COMMON_CLK
612	/* register clk in common clk framework */
613	pcf8563_clkout_register_clk(pcf8563);
614#endif
615
616	return 0;
617}
618
619static const struct i2c_device_id pcf8563_id[] = {
620	{ "pcf8563", 0 },
621	{ "rtc8564", 0 },
 
622	{ }
623};
624MODULE_DEVICE_TABLE(i2c, pcf8563_id);
625
626#ifdef CONFIG_OF
627static const struct of_device_id pcf8563_of_match[] = {
628	{ .compatible = "nxp,pcf8563" },
629	{ .compatible = "epson,rtc8564" },
630	{ .compatible = "microcrystal,rv8564" },
 
631	{}
632};
633MODULE_DEVICE_TABLE(of, pcf8563_of_match);
634#endif
635
636static struct i2c_driver pcf8563_driver = {
637	.driver		= {
638		.name	= "rtc-pcf8563",
639		.of_match_table = of_match_ptr(pcf8563_of_match),
640	},
641	.probe		= pcf8563_probe,
642	.id_table	= pcf8563_id,
643};
644
645module_i2c_driver(pcf8563_driver);
646
647MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
648MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
649MODULE_LICENSE("GPL");