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v3.1
  1/*
  2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
  3 *
  4 *  Copyright (C) 2005 James Chapman (ds1337 core)
  5 *  Copyright (C) 2006 David Brownell
  6 *  Copyright (C) 2009 Matthias Fuchs (rx8025 support)
 
  7 *
  8 * This program is free software; you can redistribute it and/or modify
  9 * it under the terms of the GNU General Public License version 2 as
 10 * published by the Free Software Foundation.
 11 */
 12
 13#include <linux/module.h>
 
 
 14#include <linux/init.h>
 
 
 
 15#include <linux/slab.h>
 16#include <linux/i2c.h>
 17#include <linux/string.h>
 18#include <linux/rtc.h>
 19#include <linux/bcd.h>
 20
 21
 22
 23/* We can't determine type by probing, but if we expect pre-Linux code
 
 24 * to have set the chip up as a clock (turning on the oscillator and
 25 * setting the date and time), Linux can ignore the non-clock features.
 26 * That's a natural job for a factory or repair bench.
 27 */
 28enum ds_type {
 29	ds_1307,
 30	ds_1337,
 31	ds_1338,
 32	ds_1339,
 33	ds_1340,
 34	ds_1388,
 35	ds_3231,
 36	m41t00,
 
 37	rx_8025,
 38	// rs5c372 too?  different address...
 
 39};
 40
 41
 42/* RTC registers don't differ much, except for the century flag */
 43#define DS1307_REG_SECS		0x00	/* 00-59 */
 44#	define DS1307_BIT_CH		0x80
 45#	define DS1340_BIT_nEOSC		0x80
 
 46#define DS1307_REG_MIN		0x01	/* 00-59 */
 47#define DS1307_REG_HOUR		0x02	/* 00-23, or 1-12{am,pm} */
 48#	define DS1307_BIT_12HR		0x40	/* in REG_HOUR */
 49#	define DS1307_BIT_PM		0x20	/* in REG_HOUR */
 50#	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */
 51#	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */
 52#define DS1307_REG_WDAY		0x03	/* 01-07 */
 
 53#define DS1307_REG_MDAY		0x04	/* 01-31 */
 54#define DS1307_REG_MONTH	0x05	/* 01-12 */
 55#	define DS1337_BIT_CENTURY	0x80	/* in REG_MONTH */
 56#define DS1307_REG_YEAR		0x06	/* 00-99 */
 57
 58/* Other registers (control, status, alarms, trickle charge, NVRAM, etc)
 
 59 * start at 7, and they differ a LOT. Only control and status matter for
 60 * basic RTC date and time functionality; be careful using them.
 61 */
 62#define DS1307_REG_CONTROL	0x07		/* or ds1338 */
 63#	define DS1307_BIT_OUT		0x80
 64#	define DS1338_BIT_OSF		0x20
 65#	define DS1307_BIT_SQWE		0x10
 66#	define DS1307_BIT_RS1		0x02
 67#	define DS1307_BIT_RS0		0x01
 68#define DS1337_REG_CONTROL	0x0e
 69#	define DS1337_BIT_nEOSC		0x80
 70#	define DS1339_BIT_BBSQI		0x20
 71#	define DS3231_BIT_BBSQW		0x40 /* same as BBSQI */
 72#	define DS1337_BIT_RS2		0x10
 73#	define DS1337_BIT_RS1		0x08
 74#	define DS1337_BIT_INTCN		0x04
 75#	define DS1337_BIT_A2IE		0x02
 76#	define DS1337_BIT_A1IE		0x01
 77#define DS1340_REG_CONTROL	0x07
 78#	define DS1340_BIT_OUT		0x80
 79#	define DS1340_BIT_FT		0x40
 80#	define DS1340_BIT_CALIB_SIGN	0x20
 81#	define DS1340_M_CALIBRATION	0x1f
 82#define DS1340_REG_FLAG		0x09
 83#	define DS1340_BIT_OSF		0x80
 84#define DS1337_REG_STATUS	0x0f
 85#	define DS1337_BIT_OSF		0x80
 
 86#	define DS1337_BIT_A2I		0x02
 87#	define DS1337_BIT_A1I		0x01
 88#define DS1339_REG_ALARM1_SECS	0x07
 89#define DS1339_REG_TRICKLE	0x10
 
 90
 91#define RX8025_REG_CTRL1	0x0e
 92#	define RX8025_BIT_2412		0x20
 93#define RX8025_REG_CTRL2	0x0f
 94#	define RX8025_BIT_PON		0x10
 95#	define RX8025_BIT_VDET		0x40
 96#	define RX8025_BIT_XST		0x20
 97
 98
 99struct ds1307 {
100	u8			offset; /* register's offset */
101	u8			regs[11];
 
 
102	enum ds_type		type;
103	unsigned long		flags;
104#define HAS_NVRAM	0		/* bit 0 == sysfs file active */
105#define HAS_ALARM	1		/* bit 1 == irq claimed */
106	struct i2c_client	*client;
107	struct rtc_device	*rtc;
108	struct work_struct	work;
109	s32 (*read_block_data)(const struct i2c_client *client, u8 command,
110			       u8 length, u8 *values);
111	s32 (*write_block_data)(const struct i2c_client *client, u8 command,
112				u8 length, const u8 *values);
 
 
 
113};
114
115struct chip_desc {
116	unsigned		nvram56:1;
117	unsigned		alarm:1;
 
 
 
 
 
118};
119
120static const struct chip_desc chips[] = {
121[ds_1307] = {
122	.nvram56	= 1,
123},
124[ds_1337] = {
125	.alarm		= 1,
126},
127[ds_1338] = {
128	.nvram56	= 1,
129},
130[ds_1339] = {
131	.alarm		= 1,
132},
133[ds_1340] = {
134},
135[ds_3231] = {
136	.alarm		= 1,
137},
138[m41t00] = {
139},
140[rx_8025] = {
141}, };
 
 
 
 
 
 
 
 
 
 
 
 
 
 
142
143static const struct i2c_device_id ds1307_id[] = {
144	{ "ds1307", ds_1307 },
145	{ "ds1337", ds_1337 },
146	{ "ds1338", ds_1338 },
147	{ "ds1339", ds_1339 },
148	{ "ds1388", ds_1388 },
149	{ "ds1340", ds_1340 },
150	{ "ds3231", ds_3231 },
151	{ "m41t00", m41t00 },
 
 
152	{ "pt7c4338", ds_1307 },
153	{ "rx8025", rx_8025 },
 
154	{ }
155};
156MODULE_DEVICE_TABLE(i2c, ds1307_id);
157
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
158/*----------------------------------------------------------------------*/
159
160#define BLOCK_DATA_MAX_TRIES 10
161
162static s32 ds1307_read_block_data_once(const struct i2c_client *client,
163				       u8 command, u8 length, u8 *values)
164{
165	s32 i, data;
166
167	for (i = 0; i < length; i++) {
168		data = i2c_smbus_read_byte_data(client, command + i);
169		if (data < 0)
170			return data;
171		values[i] = data;
172	}
173	return i;
174}
175
176static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
177				  u8 length, u8 *values)
178{
179	u8 oldvalues[I2C_SMBUS_BLOCK_MAX];
180	s32 ret;
181	int tries = 0;
182
183	dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
184	ret = ds1307_read_block_data_once(client, command, length, values);
185	if (ret < 0)
186		return ret;
187	do {
188		if (++tries > BLOCK_DATA_MAX_TRIES) {
189			dev_err(&client->dev,
190				"ds1307_read_block_data failed\n");
191			return -EIO;
192		}
193		memcpy(oldvalues, values, length);
194		ret = ds1307_read_block_data_once(client, command, length,
195						  values);
196		if (ret < 0)
197			return ret;
198	} while (memcmp(oldvalues, values, length));
199	return length;
200}
201
202static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
203				   u8 length, const u8 *values)
204{
205	u8 currvalues[I2C_SMBUS_BLOCK_MAX];
206	int tries = 0;
207
208	dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
209	do {
210		s32 i, ret;
211
212		if (++tries > BLOCK_DATA_MAX_TRIES) {
213			dev_err(&client->dev,
214				"ds1307_write_block_data failed\n");
215			return -EIO;
216		}
217		for (i = 0; i < length; i++) {
218			ret = i2c_smbus_write_byte_data(client, command + i,
219							values[i]);
220			if (ret < 0)
221				return ret;
222		}
223		ret = ds1307_read_block_data_once(client, command, length,
224						  currvalues);
225		if (ret < 0)
226			return ret;
227	} while (memcmp(currvalues, values, length));
228	return length;
229}
230
231/*----------------------------------------------------------------------*/
232
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
233/*
234 * The IRQ logic includes a "real" handler running in IRQ context just
235 * long enough to schedule this workqueue entry.   We need a task context
236 * to talk to the RTC, since I2C I/O calls require that; and disable the
237 * IRQ until we clear its status on the chip, so that this handler can
238 * work with any type of triggering (not just falling edge).
239 *
240 * The ds1337 and ds1339 both have two alarms, but we only use the first
241 * one (with a "seconds" field).  For ds1337 we expect nINTA is our alarm
242 * signal; ds1339 chips have only one alarm signal.
243 */
244static void ds1307_work(struct work_struct *work)
245{
246	struct ds1307		*ds1307;
247	struct i2c_client	*client;
248	struct mutex		*lock;
249	int			stat, control;
250
251	ds1307 = container_of(work, struct ds1307, work);
252	client = ds1307->client;
253	lock = &ds1307->rtc->ops_lock;
254
255	mutex_lock(lock);
256	stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
257	if (stat < 0)
258		goto out;
259
260	if (stat & DS1337_BIT_A1I) {
261		stat &= ~DS1337_BIT_A1I;
262		i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
263
264		control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
265		if (control < 0)
266			goto out;
267
268		control &= ~DS1337_BIT_A1IE;
269		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
270
271		rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
272	}
273
274out:
275	if (test_bit(HAS_ALARM, &ds1307->flags))
276		enable_irq(client->irq);
277	mutex_unlock(lock);
278}
279
280static irqreturn_t ds1307_irq(int irq, void *dev_id)
281{
282	struct i2c_client	*client = dev_id;
283	struct ds1307		*ds1307 = i2c_get_clientdata(client);
284
285	disable_irq_nosync(irq);
286	schedule_work(&ds1307->work);
287	return IRQ_HANDLED;
288}
289
290/*----------------------------------------------------------------------*/
291
292static int ds1307_get_time(struct device *dev, struct rtc_time *t)
293{
294	struct ds1307	*ds1307 = dev_get_drvdata(dev);
295	int		tmp;
296
297	/* read the RTC date and time registers all at once */
298	tmp = ds1307->read_block_data(ds1307->client,
299		ds1307->offset, 7, ds1307->regs);
300	if (tmp != 7) {
301		dev_err(dev, "%s error %d\n", "read", tmp);
302		return -EIO;
303	}
304
305	dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
306			"read",
307			ds1307->regs[0], ds1307->regs[1],
308			ds1307->regs[2], ds1307->regs[3],
309			ds1307->regs[4], ds1307->regs[5],
310			ds1307->regs[6]);
311
312	t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
313	t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
314	tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
315	t->tm_hour = bcd2bin(tmp);
316	t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
317	t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
318	tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
319	t->tm_mon = bcd2bin(tmp) - 1;
320
321	/* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */
322	t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
323
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
324	dev_dbg(dev, "%s secs=%d, mins=%d, "
325		"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
326		"read", t->tm_sec, t->tm_min,
327		t->tm_hour, t->tm_mday,
328		t->tm_mon, t->tm_year, t->tm_wday);
329
330	/* initial clock setting can be undefined */
331	return rtc_valid_tm(t);
332}
333
334static int ds1307_set_time(struct device *dev, struct rtc_time *t)
335{
336	struct ds1307	*ds1307 = dev_get_drvdata(dev);
337	int		result;
338	int		tmp;
339	u8		*buf = ds1307->regs;
340
341	dev_dbg(dev, "%s secs=%d, mins=%d, "
342		"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
343		"write", t->tm_sec, t->tm_min,
344		t->tm_hour, t->tm_mday,
345		t->tm_mon, t->tm_year, t->tm_wday);
346
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
347	buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
348	buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
349	buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
350	buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
351	buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
352	buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
353
354	/* assume 20YY not 19YY */
355	tmp = t->tm_year - 100;
356	buf[DS1307_REG_YEAR] = bin2bcd(tmp);
357
358	switch (ds1307->type) {
359	case ds_1337:
360	case ds_1339:
361	case ds_3231:
362		buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
 
363		break;
364	case ds_1340:
365		buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
366				| DS1340_BIT_CENTURY;
 
 
 
 
 
 
 
 
 
 
367		break;
368	default:
369		break;
370	}
371
372	dev_dbg(dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n",
373		"write", buf[0], buf[1], buf[2], buf[3],
374		buf[4], buf[5], buf[6]);
375
376	result = ds1307->write_block_data(ds1307->client,
377		ds1307->offset, 7, buf);
378	if (result < 0) {
379		dev_err(dev, "%s error %d\n", "write", result);
380		return result;
381	}
382	return 0;
383}
384
385static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
386{
387	struct i2c_client       *client = to_i2c_client(dev);
388	struct ds1307		*ds1307 = i2c_get_clientdata(client);
389	int			ret;
390
391	if (!test_bit(HAS_ALARM, &ds1307->flags))
392		return -EINVAL;
393
394	/* read all ALARM1, ALARM2, and status registers at once */
395	ret = ds1307->read_block_data(client,
396			DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
397	if (ret != 9) {
398		dev_err(dev, "%s error %d\n", "alarm read", ret);
399		return -EIO;
400	}
401
402	dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
403			"alarm read",
404			ds1307->regs[0], ds1307->regs[1],
405			ds1307->regs[2], ds1307->regs[3],
406			ds1307->regs[4], ds1307->regs[5],
407			ds1307->regs[6], ds1307->regs[7],
408			ds1307->regs[8]);
409
410	/* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
 
411	 * and that all four fields are checked matches
412	 */
413	t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
414	t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
415	t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
416	t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
417	t->time.tm_mon = -1;
418	t->time.tm_year = -1;
419	t->time.tm_wday = -1;
420	t->time.tm_yday = -1;
421	t->time.tm_isdst = -1;
422
423	/* ... and status */
424	t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
425	t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
426
427	dev_dbg(dev, "%s secs=%d, mins=%d, "
428		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
429		"alarm read", t->time.tm_sec, t->time.tm_min,
430		t->time.tm_hour, t->time.tm_mday,
431		t->enabled, t->pending);
432
433	return 0;
434}
435
436static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
437{
438	struct i2c_client       *client = to_i2c_client(dev);
439	struct ds1307		*ds1307 = i2c_get_clientdata(client);
440	unsigned char		*buf = ds1307->regs;
441	u8			control, status;
442	int			ret;
443
444	if (!test_bit(HAS_ALARM, &ds1307->flags))
445		return -EINVAL;
446
447	dev_dbg(dev, "%s secs=%d, mins=%d, "
448		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
449		"alarm set", t->time.tm_sec, t->time.tm_min,
450		t->time.tm_hour, t->time.tm_mday,
451		t->enabled, t->pending);
452
453	/* read current status of both alarms and the chip */
454	ret = ds1307->read_block_data(client,
455			DS1339_REG_ALARM1_SECS, 9, buf);
456	if (ret != 9) {
457		dev_err(dev, "%s error %d\n", "alarm write", ret);
458		return -EIO;
459	}
460	control = ds1307->regs[7];
461	status = ds1307->regs[8];
462
463	dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
464			"alarm set (old status)",
465			ds1307->regs[0], ds1307->regs[1],
466			ds1307->regs[2], ds1307->regs[3],
467			ds1307->regs[4], ds1307->regs[5],
468			ds1307->regs[6], control, status);
469
470	/* set ALARM1, using 24 hour and day-of-month modes */
471	buf[0] = bin2bcd(t->time.tm_sec);
472	buf[1] = bin2bcd(t->time.tm_min);
473	buf[2] = bin2bcd(t->time.tm_hour);
474	buf[3] = bin2bcd(t->time.tm_mday);
475
476	/* set ALARM2 to non-garbage */
477	buf[4] = 0;
478	buf[5] = 0;
479	buf[6] = 0;
480
481	/* optionally enable ALARM1 */
482	buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
483	if (t->enabled) {
484		dev_dbg(dev, "alarm IRQ armed\n");
485		buf[7] |= DS1337_BIT_A1IE;	/* only ALARM1 is used */
486	}
487	buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
488
489	ret = ds1307->write_block_data(client,
490			DS1339_REG_ALARM1_SECS, 9, buf);
491	if (ret < 0) {
492		dev_err(dev, "can't set alarm time\n");
493		return ret;
494	}
495
 
 
 
 
 
 
 
496	return 0;
497}
498
499static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
500{
501	struct i2c_client	*client = to_i2c_client(dev);
502	struct ds1307		*ds1307 = i2c_get_clientdata(client);
503	int			ret;
504
505	if (!test_bit(HAS_ALARM, &ds1307->flags))
506		return -ENOTTY;
507
508	ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
509	if (ret < 0)
510		return ret;
511
512	if (enabled)
513		ret |= DS1337_BIT_A1IE;
514	else
515		ret &= ~DS1337_BIT_A1IE;
516
517	ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
518	if (ret < 0)
519		return ret;
520
521	return 0;
522}
523
524static const struct rtc_class_ops ds13xx_rtc_ops = {
525	.read_time	= ds1307_get_time,
526	.set_time	= ds1307_set_time,
527	.read_alarm	= ds1337_read_alarm,
528	.set_alarm	= ds1337_set_alarm,
529	.alarm_irq_enable = ds1307_alarm_irq_enable,
530};
531
532/*----------------------------------------------------------------------*/
533
534#define NVRAM_SIZE	56
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
535
536static ssize_t
537ds1307_nvram_read(struct file *filp, struct kobject *kobj,
538		struct bin_attribute *attr,
539		char *buf, loff_t off, size_t count)
540{
541	struct i2c_client	*client;
542	struct ds1307		*ds1307;
543	int			result;
544
545	client = kobj_to_i2c_client(kobj);
546	ds1307 = i2c_get_clientdata(client);
547
548	if (unlikely(off >= NVRAM_SIZE))
549		return 0;
550	if ((off + count) > NVRAM_SIZE)
551		count = NVRAM_SIZE - off;
552	if (unlikely(!count))
553		return count;
554
555	result = ds1307->read_block_data(client, 8 + off, count, buf);
556	if (result < 0)
557		dev_err(&client->dev, "%s error %d\n", "nvram read", result);
558	return result;
559}
560
561static ssize_t
562ds1307_nvram_write(struct file *filp, struct kobject *kobj,
563		struct bin_attribute *attr,
564		char *buf, loff_t off, size_t count)
565{
566	struct i2c_client	*client;
567	struct ds1307		*ds1307;
568	int			result;
569
570	client = kobj_to_i2c_client(kobj);
571	ds1307 = i2c_get_clientdata(client);
572
573	if (unlikely(off >= NVRAM_SIZE))
574		return -EFBIG;
575	if ((off + count) > NVRAM_SIZE)
576		count = NVRAM_SIZE - off;
577	if (unlikely(!count))
578		return count;
579
580	result = ds1307->write_block_data(client, 8 + off, count, buf);
581	if (result < 0) {
582		dev_err(&client->dev, "%s error %d\n", "nvram write", result);
583		return result;
584	}
585	return count;
586}
587
588static struct bin_attribute nvram = {
589	.attr = {
590		.name	= "nvram",
591		.mode	= S_IRUGO | S_IWUSR,
592	},
593
594	.read	= ds1307_nvram_read,
595	.write	= ds1307_nvram_write,
596	.size	= NVRAM_SIZE,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
597};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
598
599/*----------------------------------------------------------------------*/
600
601static struct i2c_driver ds1307_driver;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
602
603static int __devinit ds1307_probe(struct i2c_client *client,
604				  const struct i2c_device_id *id)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
605{
606	struct ds1307		*ds1307;
607	int			err = -ENODEV;
608	int			tmp;
609	const struct chip_desc	*chip = &chips[id->driver_data];
610	struct i2c_adapter	*adapter = to_i2c_adapter(client->dev.parent);
611	int			want_irq = false;
 
612	unsigned char		*buf;
 
 
 
 
 
 
613	static const int	bbsqi_bitpos[] = {
614		[ds_1337] = 0,
615		[ds_1339] = DS1339_BIT_BBSQI,
616		[ds_3231] = DS3231_BIT_BBSQW,
617	};
 
618
619	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
620	    && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
621		return -EIO;
622
623	if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL)))
 
624		return -ENOMEM;
625
626	i2c_set_clientdata(client, ds1307);
627
628	ds1307->client	= client;
629	ds1307->type	= id->driver_data;
630	ds1307->offset	= 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
631
632	buf = ds1307->regs;
633	if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
634		ds1307->read_block_data = i2c_smbus_read_i2c_block_data;
635		ds1307->write_block_data = i2c_smbus_write_i2c_block_data;
636	} else {
637		ds1307->read_block_data = ds1307_read_block_data;
638		ds1307->write_block_data = ds1307_write_block_data;
639	}
640
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
641	switch (ds1307->type) {
642	case ds_1337:
643	case ds_1339:
644	case ds_3231:
645		/* has IRQ? */
646		if (ds1307->client->irq > 0 && chip->alarm) {
647			INIT_WORK(&ds1307->work, ds1307_work);
648			want_irq = true;
649		}
650		/* get registers that the "rtc" read below won't read... */
651		tmp = ds1307->read_block_data(ds1307->client,
652				DS1337_REG_CONTROL, 2, buf);
653		if (tmp != 2) {
654			pr_debug("read error %d\n", tmp);
655			err = -EIO;
656			goto exit_free;
657		}
658
659		/* oscillator off?  turn it on, so clock can tick. */
660		if (ds1307->regs[0] & DS1337_BIT_nEOSC)
661			ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
662
663		/* Using IRQ?  Disable the square wave and both alarms.
 
 
664		 * For some variants, be sure alarms can trigger when we're
665		 * running on Vbackup (BBSQI/BBSQW)
666		 */
667		if (want_irq) {
 
668			ds1307->regs[0] |= DS1337_BIT_INTCN
669					| bbsqi_bitpos[ds1307->type];
670			ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
 
 
671		}
672
673		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
674							ds1307->regs[0]);
675
676		/* oscillator fault?  clear flag, and warn */
677		if (ds1307->regs[1] & DS1337_BIT_OSF) {
678			i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
679				ds1307->regs[1] & ~DS1337_BIT_OSF);
680			dev_warn(&client->dev, "SET TIME!\n");
681		}
682		break;
683
684	case rx_8025:
685		tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
686				RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
687		if (tmp != 2) {
688			pr_debug("read error %d\n", tmp);
689			err = -EIO;
690			goto exit_free;
691		}
692
693		/* oscillator off?  turn it on, so clock can tick. */
694		if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
695			ds1307->regs[1] |= RX8025_BIT_XST;
696			i2c_smbus_write_byte_data(client,
697						  RX8025_REG_CTRL2 << 4 | 0x08,
698						  ds1307->regs[1]);
699			dev_warn(&client->dev,
700				 "oscillator stop detected - SET TIME!\n");
701		}
702
703		if (ds1307->regs[1] & RX8025_BIT_PON) {
704			ds1307->regs[1] &= ~RX8025_BIT_PON;
705			i2c_smbus_write_byte_data(client,
706						  RX8025_REG_CTRL2 << 4 | 0x08,
707						  ds1307->regs[1]);
708			dev_warn(&client->dev, "power-on detected\n");
709		}
710
711		if (ds1307->regs[1] & RX8025_BIT_VDET) {
712			ds1307->regs[1] &= ~RX8025_BIT_VDET;
713			i2c_smbus_write_byte_data(client,
714						  RX8025_REG_CTRL2 << 4 | 0x08,
715						  ds1307->regs[1]);
716			dev_warn(&client->dev, "voltage drop detected\n");
717		}
718
719		/* make sure we are running in 24hour mode */
720		if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
721			u8 hour;
722
723			/* switch to 24 hour mode */
724			i2c_smbus_write_byte_data(client,
725						  RX8025_REG_CTRL1 << 4 | 0x08,
726						  ds1307->regs[0] |
727						  RX8025_BIT_2412);
728
729			tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
730					RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
731			if (tmp != 2) {
732				pr_debug("read error %d\n", tmp);
733				err = -EIO;
734				goto exit_free;
735			}
736
737			/* correct hour */
738			hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
739			if (hour == 12)
740				hour = 0;
741			if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
742				hour += 12;
743
744			i2c_smbus_write_byte_data(client,
745						  DS1307_REG_HOUR << 4 | 0x08,
746						  hour);
747		}
748		break;
749	case ds_1388:
750		ds1307->offset = 1; /* Seconds starts at 1 */
751		break;
 
 
 
 
 
 
 
752	default:
753		break;
754	}
755
756read_rtc:
757	/* read RTC registers */
758	tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
759	if (tmp != 8) {
760		pr_debug("read error %d\n", tmp);
761		err = -EIO;
762		goto exit_free;
763	}
764
765	/* minimal sanity checking; some chips (like DS1340) don't
 
766	 * specify the extra bits as must-be-zero, but there are
767	 * still a few values that are clearly out-of-range.
768	 */
769	tmp = ds1307->regs[DS1307_REG_SECS];
770	switch (ds1307->type) {
771	case ds_1307:
772	case m41t00:
773		/* clock halted?  turn it on, so clock can tick. */
774		if (tmp & DS1307_BIT_CH) {
775			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
776			dev_warn(&client->dev, "SET TIME!\n");
777			goto read_rtc;
778		}
779		break;
780	case ds_1338:
781		/* clock halted?  turn it on, so clock can tick. */
782		if (tmp & DS1307_BIT_CH)
783			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
784
785		/* oscillator fault?  clear flag, and warn */
786		if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
787			i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
788					ds1307->regs[DS1307_REG_CONTROL]
789					& ~DS1338_BIT_OSF);
790			dev_warn(&client->dev, "SET TIME!\n");
791			goto read_rtc;
792		}
793		break;
794	case ds_1340:
795		/* clock halted?  turn it on, so clock can tick. */
796		if (tmp & DS1340_BIT_nEOSC)
797			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
798
799		tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
800		if (tmp < 0) {
801			pr_debug("read error %d\n", tmp);
802			err = -EIO;
803			goto exit_free;
804		}
805
806		/* oscillator fault?  clear flag, and warn */
807		if (tmp & DS1340_BIT_OSF) {
808			i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
809			dev_warn(&client->dev, "SET TIME!\n");
810		}
811		break;
812	case rx_8025:
813	case ds_1337:
814	case ds_1339:
815	case ds_1388:
816	case ds_3231:
 
 
 
 
 
 
 
 
 
 
 
 
 
817		break;
818	}
819
820	tmp = ds1307->regs[DS1307_REG_HOUR];
821	switch (ds1307->type) {
822	case ds_1340:
823	case m41t00:
824		/* NOTE: ignores century bits; fix before deploying
 
825		 * systems that will run through year 2100.
826		 */
827		break;
828	case rx_8025:
829		break;
830	default:
831		if (!(tmp & DS1307_BIT_12HR))
832			break;
833
834		/* Be sure we're in 24 hour mode.  Multi-master systems
 
835		 * take note...
836		 */
837		tmp = bcd2bin(tmp & 0x1f);
838		if (tmp == 12)
839			tmp = 0;
840		if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
841			tmp += 12;
842		i2c_smbus_write_byte_data(client,
843				ds1307->offset + DS1307_REG_HOUR,
844				bin2bcd(tmp));
845	}
846
847	ds1307->rtc = rtc_device_register(client->name, &client->dev,
848				&ds13xx_rtc_ops, THIS_MODULE);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
849	if (IS_ERR(ds1307->rtc)) {
850		err = PTR_ERR(ds1307->rtc);
851		dev_err(&client->dev,
852			"unable to register the class device\n");
853		goto exit_free;
 
 
 
 
 
854	}
855
856	if (want_irq) {
857		err = request_irq(client->irq, ds1307_irq, IRQF_SHARED,
858			  ds1307->rtc->name, client);
 
 
859		if (err) {
860			dev_err(&client->dev,
861				"unable to request IRQ!\n");
862			goto exit_irq;
863		}
864
865		device_set_wakeup_capable(&client->dev, 1);
866		set_bit(HAS_ALARM, &ds1307->flags);
867		dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
868	}
869
870	if (chip->nvram56) {
871		err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
872		if (err == 0) {
873			set_bit(HAS_NVRAM, &ds1307->flags);
874			dev_info(&client->dev, "56 bytes nvram\n");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
875		}
876	}
877
 
 
 
878	return 0;
879
880exit_irq:
881	rtc_device_unregister(ds1307->rtc);
882exit_free:
883	kfree(ds1307);
884	return err;
885}
886
887static int __devexit ds1307_remove(struct i2c_client *client)
888{
889	struct ds1307		*ds1307 = i2c_get_clientdata(client);
890
891	if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
892		free_irq(client->irq, client);
893		cancel_work_sync(&ds1307->work);
894	}
895
896	if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
897		sysfs_remove_bin_file(&client->dev.kobj, &nvram);
898
899	rtc_device_unregister(ds1307->rtc);
900	kfree(ds1307);
901	return 0;
902}
903
904static struct i2c_driver ds1307_driver = {
905	.driver = {
906		.name	= "rtc-ds1307",
907		.owner	= THIS_MODULE,
908	},
909	.probe		= ds1307_probe,
910	.remove		= __devexit_p(ds1307_remove),
911	.id_table	= ds1307_id,
912};
913
914static int __init ds1307_init(void)
915{
916	return i2c_add_driver(&ds1307_driver);
917}
918module_init(ds1307_init);
919
920static void __exit ds1307_exit(void)
921{
922	i2c_del_driver(&ds1307_driver);
923}
924module_exit(ds1307_exit);
925
926MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
927MODULE_LICENSE("GPL");
v4.10.11
   1/*
   2 * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips.
   3 *
   4 *  Copyright (C) 2005 James Chapman (ds1337 core)
   5 *  Copyright (C) 2006 David Brownell
   6 *  Copyright (C) 2009 Matthias Fuchs (rx8025 support)
   7 *  Copyright (C) 2012 Bertrand Achard (nvram access fixes)
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 */
  13
  14#include <linux/acpi.h>
  15#include <linux/bcd.h>
  16#include <linux/i2c.h>
  17#include <linux/init.h>
  18#include <linux/module.h>
  19#include <linux/rtc/ds1307.h>
  20#include <linux/rtc.h>
  21#include <linux/slab.h>
 
  22#include <linux/string.h>
  23#include <linux/hwmon.h>
  24#include <linux/hwmon-sysfs.h>
  25#include <linux/clk-provider.h>
 
  26
  27/*
  28 * We can't determine type by probing, but if we expect pre-Linux code
  29 * to have set the chip up as a clock (turning on the oscillator and
  30 * setting the date and time), Linux can ignore the non-clock features.
  31 * That's a natural job for a factory or repair bench.
  32 */
  33enum ds_type {
  34	ds_1307,
  35	ds_1337,
  36	ds_1338,
  37	ds_1339,
  38	ds_1340,
  39	ds_1388,
  40	ds_3231,
  41	m41t00,
  42	mcp794xx,
  43	rx_8025,
  44	last_ds_type /* always last */
  45	/* rs5c372 too?  different address... */
  46};
  47
  48
  49/* RTC registers don't differ much, except for the century flag */
  50#define DS1307_REG_SECS		0x00	/* 00-59 */
  51#	define DS1307_BIT_CH		0x80
  52#	define DS1340_BIT_nEOSC		0x80
  53#	define MCP794XX_BIT_ST		0x80
  54#define DS1307_REG_MIN		0x01	/* 00-59 */
  55#define DS1307_REG_HOUR		0x02	/* 00-23, or 1-12{am,pm} */
  56#	define DS1307_BIT_12HR		0x40	/* in REG_HOUR */
  57#	define DS1307_BIT_PM		0x20	/* in REG_HOUR */
  58#	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */
  59#	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */
  60#define DS1307_REG_WDAY		0x03	/* 01-07 */
  61#	define MCP794XX_BIT_VBATEN	0x08
  62#define DS1307_REG_MDAY		0x04	/* 01-31 */
  63#define DS1307_REG_MONTH	0x05	/* 01-12 */
  64#	define DS1337_BIT_CENTURY	0x80	/* in REG_MONTH */
  65#define DS1307_REG_YEAR		0x06	/* 00-99 */
  66
  67/*
  68 * Other registers (control, status, alarms, trickle charge, NVRAM, etc)
  69 * start at 7, and they differ a LOT. Only control and status matter for
  70 * basic RTC date and time functionality; be careful using them.
  71 */
  72#define DS1307_REG_CONTROL	0x07		/* or ds1338 */
  73#	define DS1307_BIT_OUT		0x80
  74#	define DS1338_BIT_OSF		0x20
  75#	define DS1307_BIT_SQWE		0x10
  76#	define DS1307_BIT_RS1		0x02
  77#	define DS1307_BIT_RS0		0x01
  78#define DS1337_REG_CONTROL	0x0e
  79#	define DS1337_BIT_nEOSC		0x80
  80#	define DS1339_BIT_BBSQI		0x20
  81#	define DS3231_BIT_BBSQW		0x40 /* same as BBSQI */
  82#	define DS1337_BIT_RS2		0x10
  83#	define DS1337_BIT_RS1		0x08
  84#	define DS1337_BIT_INTCN		0x04
  85#	define DS1337_BIT_A2IE		0x02
  86#	define DS1337_BIT_A1IE		0x01
  87#define DS1340_REG_CONTROL	0x07
  88#	define DS1340_BIT_OUT		0x80
  89#	define DS1340_BIT_FT		0x40
  90#	define DS1340_BIT_CALIB_SIGN	0x20
  91#	define DS1340_M_CALIBRATION	0x1f
  92#define DS1340_REG_FLAG		0x09
  93#	define DS1340_BIT_OSF		0x80
  94#define DS1337_REG_STATUS	0x0f
  95#	define DS1337_BIT_OSF		0x80
  96#	define DS3231_BIT_EN32KHZ	0x08
  97#	define DS1337_BIT_A2I		0x02
  98#	define DS1337_BIT_A1I		0x01
  99#define DS1339_REG_ALARM1_SECS	0x07
 100
 101#define DS13XX_TRICKLE_CHARGER_MAGIC	0xa0
 102
 103#define RX8025_REG_CTRL1	0x0e
 104#	define RX8025_BIT_2412		0x20
 105#define RX8025_REG_CTRL2	0x0f
 106#	define RX8025_BIT_PON		0x10
 107#	define RX8025_BIT_VDET		0x40
 108#	define RX8025_BIT_XST		0x20
 109
 110
 111struct ds1307 {
 112	u8			offset; /* register's offset */
 113	u8			regs[11];
 114	u16			nvram_offset;
 115	struct bin_attribute	*nvram;
 116	enum ds_type		type;
 117	unsigned long		flags;
 118#define HAS_NVRAM	0		/* bit 0 == sysfs file active */
 119#define HAS_ALARM	1		/* bit 1 == irq claimed */
 120	struct i2c_client	*client;
 121	struct rtc_device	*rtc;
 
 122	s32 (*read_block_data)(const struct i2c_client *client, u8 command,
 123			       u8 length, u8 *values);
 124	s32 (*write_block_data)(const struct i2c_client *client, u8 command,
 125				u8 length, const u8 *values);
 126#ifdef CONFIG_COMMON_CLK
 127	struct clk_hw		clks[2];
 128#endif
 129};
 130
 131struct chip_desc {
 
 132	unsigned		alarm:1;
 133	u16			nvram_offset;
 134	u16			nvram_size;
 135	u16			trickle_charger_reg;
 136	u8			trickle_charger_setup;
 137	u8			(*do_trickle_setup)(struct i2c_client *, uint32_t, bool);
 138};
 139
 140static u8 do_trickle_setup_ds1339(struct i2c_client *,
 141				  uint32_t ohms, bool diode);
 142
 143static struct chip_desc chips[last_ds_type] = {
 144	[ds_1307] = {
 145		.nvram_offset	= 8,
 146		.nvram_size	= 56,
 147	},
 148	[ds_1337] = {
 149		.alarm		= 1,
 150	},
 151	[ds_1338] = {
 152		.nvram_offset	= 8,
 153		.nvram_size	= 56,
 154	},
 155	[ds_1339] = {
 156		.alarm		= 1,
 157		.trickle_charger_reg = 0x10,
 158		.do_trickle_setup = &do_trickle_setup_ds1339,
 159	},
 160	[ds_1340] = {
 161		.trickle_charger_reg = 0x08,
 162	},
 163	[ds_1388] = {
 164		.trickle_charger_reg = 0x0a,
 165	},
 166	[ds_3231] = {
 167		.alarm		= 1,
 168	},
 169	[mcp794xx] = {
 170		.alarm		= 1,
 171		/* this is battery backed SRAM */
 172		.nvram_offset	= 0x20,
 173		.nvram_size	= 0x40,
 174	},
 175};
 176
 177static const struct i2c_device_id ds1307_id[] = {
 178	{ "ds1307", ds_1307 },
 179	{ "ds1337", ds_1337 },
 180	{ "ds1338", ds_1338 },
 181	{ "ds1339", ds_1339 },
 182	{ "ds1388", ds_1388 },
 183	{ "ds1340", ds_1340 },
 184	{ "ds3231", ds_3231 },
 185	{ "m41t00", m41t00 },
 186	{ "mcp7940x", mcp794xx },
 187	{ "mcp7941x", mcp794xx },
 188	{ "pt7c4338", ds_1307 },
 189	{ "rx8025", rx_8025 },
 190	{ "isl12057", ds_1337 },
 191	{ }
 192};
 193MODULE_DEVICE_TABLE(i2c, ds1307_id);
 194
 195#ifdef CONFIG_ACPI
 196static const struct acpi_device_id ds1307_acpi_ids[] = {
 197	{ .id = "DS1307", .driver_data = ds_1307 },
 198	{ .id = "DS1337", .driver_data = ds_1337 },
 199	{ .id = "DS1338", .driver_data = ds_1338 },
 200	{ .id = "DS1339", .driver_data = ds_1339 },
 201	{ .id = "DS1388", .driver_data = ds_1388 },
 202	{ .id = "DS1340", .driver_data = ds_1340 },
 203	{ .id = "DS3231", .driver_data = ds_3231 },
 204	{ .id = "M41T00", .driver_data = m41t00 },
 205	{ .id = "MCP7940X", .driver_data = mcp794xx },
 206	{ .id = "MCP7941X", .driver_data = mcp794xx },
 207	{ .id = "PT7C4338", .driver_data = ds_1307 },
 208	{ .id = "RX8025", .driver_data = rx_8025 },
 209	{ .id = "ISL12057", .driver_data = ds_1337 },
 210	{ }
 211};
 212MODULE_DEVICE_TABLE(acpi, ds1307_acpi_ids);
 213#endif
 214
 215/*----------------------------------------------------------------------*/
 216
 217#define BLOCK_DATA_MAX_TRIES 10
 218
 219static s32 ds1307_read_block_data_once(const struct i2c_client *client,
 220				       u8 command, u8 length, u8 *values)
 221{
 222	s32 i, data;
 223
 224	for (i = 0; i < length; i++) {
 225		data = i2c_smbus_read_byte_data(client, command + i);
 226		if (data < 0)
 227			return data;
 228		values[i] = data;
 229	}
 230	return i;
 231}
 232
 233static s32 ds1307_read_block_data(const struct i2c_client *client, u8 command,
 234				  u8 length, u8 *values)
 235{
 236	u8 oldvalues[255];
 237	s32 ret;
 238	int tries = 0;
 239
 240	dev_dbg(&client->dev, "ds1307_read_block_data (length=%d)\n", length);
 241	ret = ds1307_read_block_data_once(client, command, length, values);
 242	if (ret < 0)
 243		return ret;
 244	do {
 245		if (++tries > BLOCK_DATA_MAX_TRIES) {
 246			dev_err(&client->dev,
 247				"ds1307_read_block_data failed\n");
 248			return -EIO;
 249		}
 250		memcpy(oldvalues, values, length);
 251		ret = ds1307_read_block_data_once(client, command, length,
 252						  values);
 253		if (ret < 0)
 254			return ret;
 255	} while (memcmp(oldvalues, values, length));
 256	return length;
 257}
 258
 259static s32 ds1307_write_block_data(const struct i2c_client *client, u8 command,
 260				   u8 length, const u8 *values)
 261{
 262	u8 currvalues[255];
 263	int tries = 0;
 264
 265	dev_dbg(&client->dev, "ds1307_write_block_data (length=%d)\n", length);
 266	do {
 267		s32 i, ret;
 268
 269		if (++tries > BLOCK_DATA_MAX_TRIES) {
 270			dev_err(&client->dev,
 271				"ds1307_write_block_data failed\n");
 272			return -EIO;
 273		}
 274		for (i = 0; i < length; i++) {
 275			ret = i2c_smbus_write_byte_data(client, command + i,
 276							values[i]);
 277			if (ret < 0)
 278				return ret;
 279		}
 280		ret = ds1307_read_block_data_once(client, command, length,
 281						  currvalues);
 282		if (ret < 0)
 283			return ret;
 284	} while (memcmp(currvalues, values, length));
 285	return length;
 286}
 287
 288/*----------------------------------------------------------------------*/
 289
 290/* These RTC devices are not designed to be connected to a SMbus adapter.
 291   SMbus limits block operations length to 32 bytes, whereas it's not
 292   limited on I2C buses. As a result, accesses may exceed 32 bytes;
 293   in that case, split them into smaller blocks */
 294
 295static s32 ds1307_native_smbus_write_block_data(const struct i2c_client *client,
 296				u8 command, u8 length, const u8 *values)
 297{
 298	u8 suboffset = 0;
 299
 300	if (length <= I2C_SMBUS_BLOCK_MAX) {
 301		s32 retval = i2c_smbus_write_i2c_block_data(client,
 302					command, length, values);
 303		if (retval < 0)
 304			return retval;
 305		return length;
 306	}
 307
 308	while (suboffset < length) {
 309		s32 retval = i2c_smbus_write_i2c_block_data(client,
 310				command + suboffset,
 311				min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
 312				values + suboffset);
 313		if (retval < 0)
 314			return retval;
 315
 316		suboffset += I2C_SMBUS_BLOCK_MAX;
 317	}
 318	return length;
 319}
 320
 321static s32 ds1307_native_smbus_read_block_data(const struct i2c_client *client,
 322				u8 command, u8 length, u8 *values)
 323{
 324	u8 suboffset = 0;
 325
 326	if (length <= I2C_SMBUS_BLOCK_MAX)
 327		return i2c_smbus_read_i2c_block_data(client,
 328					command, length, values);
 329
 330	while (suboffset < length) {
 331		s32 retval = i2c_smbus_read_i2c_block_data(client,
 332				command + suboffset,
 333				min(I2C_SMBUS_BLOCK_MAX, length - suboffset),
 334				values + suboffset);
 335		if (retval < 0)
 336			return retval;
 337
 338		suboffset += I2C_SMBUS_BLOCK_MAX;
 339	}
 340	return length;
 341}
 342
 343/*----------------------------------------------------------------------*/
 344
 345/*
 
 
 
 
 
 
 346 * The ds1337 and ds1339 both have two alarms, but we only use the first
 347 * one (with a "seconds" field).  For ds1337 we expect nINTA is our alarm
 348 * signal; ds1339 chips have only one alarm signal.
 349 */
 350static irqreturn_t ds1307_irq(int irq, void *dev_id)
 351{
 352	struct i2c_client	*client = dev_id;
 353	struct ds1307		*ds1307 = i2c_get_clientdata(client);
 354	struct mutex		*lock = &ds1307->rtc->ops_lock;
 355	int			stat, control;
 356
 
 
 
 
 357	mutex_lock(lock);
 358	stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
 359	if (stat < 0)
 360		goto out;
 361
 362	if (stat & DS1337_BIT_A1I) {
 363		stat &= ~DS1337_BIT_A1I;
 364		i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
 365
 366		control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
 367		if (control < 0)
 368			goto out;
 369
 370		control &= ~DS1337_BIT_A1IE;
 371		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
 372
 373		rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 374	}
 375
 376out:
 
 
 377	mutex_unlock(lock);
 
 378
 
 
 
 
 
 
 
 379	return IRQ_HANDLED;
 380}
 381
 382/*----------------------------------------------------------------------*/
 383
 384static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 385{
 386	struct ds1307	*ds1307 = dev_get_drvdata(dev);
 387	int		tmp;
 388
 389	/* read the RTC date and time registers all at once */
 390	tmp = ds1307->read_block_data(ds1307->client,
 391		ds1307->offset, 7, ds1307->regs);
 392	if (tmp != 7) {
 393		dev_err(dev, "%s error %d\n", "read", tmp);
 394		return -EIO;
 395	}
 396
 397	dev_dbg(dev, "%s: %7ph\n", "read", ds1307->regs);
 
 
 
 
 
 398
 399	t->tm_sec = bcd2bin(ds1307->regs[DS1307_REG_SECS] & 0x7f);
 400	t->tm_min = bcd2bin(ds1307->regs[DS1307_REG_MIN] & 0x7f);
 401	tmp = ds1307->regs[DS1307_REG_HOUR] & 0x3f;
 402	t->tm_hour = bcd2bin(tmp);
 403	t->tm_wday = bcd2bin(ds1307->regs[DS1307_REG_WDAY] & 0x07) - 1;
 404	t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f);
 405	tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f;
 406	t->tm_mon = bcd2bin(tmp) - 1;
 
 
 407	t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100;
 408
 409#ifdef CONFIG_RTC_DRV_DS1307_CENTURY
 410	switch (ds1307->type) {
 411	case ds_1337:
 412	case ds_1339:
 413	case ds_3231:
 414		if (ds1307->regs[DS1307_REG_MONTH] & DS1337_BIT_CENTURY)
 415			t->tm_year += 100;
 416		break;
 417	case ds_1340:
 418		if (ds1307->regs[DS1307_REG_HOUR] & DS1340_BIT_CENTURY)
 419			t->tm_year += 100;
 420		break;
 421	default:
 422		break;
 423	}
 424#endif
 425
 426	dev_dbg(dev, "%s secs=%d, mins=%d, "
 427		"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
 428		"read", t->tm_sec, t->tm_min,
 429		t->tm_hour, t->tm_mday,
 430		t->tm_mon, t->tm_year, t->tm_wday);
 431
 432	/* initial clock setting can be undefined */
 433	return rtc_valid_tm(t);
 434}
 435
 436static int ds1307_set_time(struct device *dev, struct rtc_time *t)
 437{
 438	struct ds1307	*ds1307 = dev_get_drvdata(dev);
 439	int		result;
 440	int		tmp;
 441	u8		*buf = ds1307->regs;
 442
 443	dev_dbg(dev, "%s secs=%d, mins=%d, "
 444		"hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n",
 445		"write", t->tm_sec, t->tm_min,
 446		t->tm_hour, t->tm_mday,
 447		t->tm_mon, t->tm_year, t->tm_wday);
 448
 449#ifdef CONFIG_RTC_DRV_DS1307_CENTURY
 450	if (t->tm_year < 100)
 451		return -EINVAL;
 452
 453	switch (ds1307->type) {
 454	case ds_1337:
 455	case ds_1339:
 456	case ds_3231:
 457	case ds_1340:
 458		if (t->tm_year > 299)
 459			return -EINVAL;
 460	default:
 461		if (t->tm_year > 199)
 462			return -EINVAL;
 463		break;
 464	}
 465#else
 466	if (t->tm_year < 100 || t->tm_year > 199)
 467		return -EINVAL;
 468#endif
 469
 470	buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec);
 471	buf[DS1307_REG_MIN] = bin2bcd(t->tm_min);
 472	buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour);
 473	buf[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1);
 474	buf[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
 475	buf[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
 476
 477	/* assume 20YY not 19YY */
 478	tmp = t->tm_year - 100;
 479	buf[DS1307_REG_YEAR] = bin2bcd(tmp);
 480
 481	switch (ds1307->type) {
 482	case ds_1337:
 483	case ds_1339:
 484	case ds_3231:
 485		if (t->tm_year > 199)
 486			buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY;
 487		break;
 488	case ds_1340:
 489		buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN;
 490		if (t->tm_year > 199)
 491			buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY;
 492		break;
 493	case mcp794xx:
 494		/*
 495		 * these bits were cleared when preparing the date/time
 496		 * values and need to be set again before writing the
 497		 * buffer out to the device.
 498		 */
 499		buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
 500		buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
 501		break;
 502	default:
 503		break;
 504	}
 505
 506	dev_dbg(dev, "%s: %7ph\n", "write", buf);
 
 
 507
 508	result = ds1307->write_block_data(ds1307->client,
 509		ds1307->offset, 7, buf);
 510	if (result < 0) {
 511		dev_err(dev, "%s error %d\n", "write", result);
 512		return result;
 513	}
 514	return 0;
 515}
 516
 517static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 518{
 519	struct i2c_client       *client = to_i2c_client(dev);
 520	struct ds1307		*ds1307 = i2c_get_clientdata(client);
 521	int			ret;
 522
 523	if (!test_bit(HAS_ALARM, &ds1307->flags))
 524		return -EINVAL;
 525
 526	/* read all ALARM1, ALARM2, and status registers at once */
 527	ret = ds1307->read_block_data(client,
 528			DS1339_REG_ALARM1_SECS, 9, ds1307->regs);
 529	if (ret != 9) {
 530		dev_err(dev, "%s error %d\n", "alarm read", ret);
 531		return -EIO;
 532	}
 533
 534	dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read",
 535		&ds1307->regs[0], &ds1307->regs[4], &ds1307->regs[7]);
 
 
 
 
 
 536
 537	/*
 538	 * report alarm time (ALARM1); assume 24 hour and day-of-month modes,
 539	 * and that all four fields are checked matches
 540	 */
 541	t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
 542	t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
 543	t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
 544	t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
 
 
 
 
 
 545
 546	/* ... and status */
 547	t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
 548	t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
 549
 550	dev_dbg(dev, "%s secs=%d, mins=%d, "
 551		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
 552		"alarm read", t->time.tm_sec, t->time.tm_min,
 553		t->time.tm_hour, t->time.tm_mday,
 554		t->enabled, t->pending);
 555
 556	return 0;
 557}
 558
 559static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 560{
 561	struct i2c_client	*client = to_i2c_client(dev);
 562	struct ds1307		*ds1307 = i2c_get_clientdata(client);
 563	unsigned char		*buf = ds1307->regs;
 564	u8			control, status;
 565	int			ret;
 566
 567	if (!test_bit(HAS_ALARM, &ds1307->flags))
 568		return -EINVAL;
 569
 570	dev_dbg(dev, "%s secs=%d, mins=%d, "
 571		"hours=%d, mday=%d, enabled=%d, pending=%d\n",
 572		"alarm set", t->time.tm_sec, t->time.tm_min,
 573		t->time.tm_hour, t->time.tm_mday,
 574		t->enabled, t->pending);
 575
 576	/* read current status of both alarms and the chip */
 577	ret = ds1307->read_block_data(client,
 578			DS1339_REG_ALARM1_SECS, 9, buf);
 579	if (ret != 9) {
 580		dev_err(dev, "%s error %d\n", "alarm write", ret);
 581		return -EIO;
 582	}
 583	control = ds1307->regs[7];
 584	status = ds1307->regs[8];
 585
 586	dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)",
 587		&ds1307->regs[0], &ds1307->regs[4], control, status);
 
 
 
 
 588
 589	/* set ALARM1, using 24 hour and day-of-month modes */
 590	buf[0] = bin2bcd(t->time.tm_sec);
 591	buf[1] = bin2bcd(t->time.tm_min);
 592	buf[2] = bin2bcd(t->time.tm_hour);
 593	buf[3] = bin2bcd(t->time.tm_mday);
 594
 595	/* set ALARM2 to non-garbage */
 596	buf[4] = 0;
 597	buf[5] = 0;
 598	buf[6] = 0;
 599
 600	/* disable alarms */
 601	buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
 
 
 
 
 602	buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
 603
 604	ret = ds1307->write_block_data(client,
 605			DS1339_REG_ALARM1_SECS, 9, buf);
 606	if (ret < 0) {
 607		dev_err(dev, "can't set alarm time\n");
 608		return ret;
 609	}
 610
 611	/* optionally enable ALARM1 */
 612	if (t->enabled) {
 613		dev_dbg(dev, "alarm IRQ armed\n");
 614		buf[7] |= DS1337_BIT_A1IE;	/* only ALARM1 is used */
 615		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, buf[7]);
 616	}
 617
 618	return 0;
 619}
 620
 621static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled)
 622{
 623	struct i2c_client	*client = to_i2c_client(dev);
 624	struct ds1307		*ds1307 = i2c_get_clientdata(client);
 625	int			ret;
 626
 627	if (!test_bit(HAS_ALARM, &ds1307->flags))
 628		return -ENOTTY;
 629
 630	ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
 631	if (ret < 0)
 632		return ret;
 633
 634	if (enabled)
 635		ret |= DS1337_BIT_A1IE;
 636	else
 637		ret &= ~DS1337_BIT_A1IE;
 638
 639	ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, ret);
 640	if (ret < 0)
 641		return ret;
 642
 643	return 0;
 644}
 645
 646static const struct rtc_class_ops ds13xx_rtc_ops = {
 647	.read_time	= ds1307_get_time,
 648	.set_time	= ds1307_set_time,
 649	.read_alarm	= ds1337_read_alarm,
 650	.set_alarm	= ds1337_set_alarm,
 651	.alarm_irq_enable = ds1307_alarm_irq_enable,
 652};
 653
 654/*----------------------------------------------------------------------*/
 655
 656/*
 657 * Alarm support for mcp794xx devices.
 658 */
 659
 660#define MCP794XX_REG_WEEKDAY		0x3
 661#define MCP794XX_REG_WEEKDAY_WDAY_MASK	0x7
 662#define MCP794XX_REG_CONTROL		0x07
 663#	define MCP794XX_BIT_ALM0_EN	0x10
 664#	define MCP794XX_BIT_ALM1_EN	0x20
 665#define MCP794XX_REG_ALARM0_BASE	0x0a
 666#define MCP794XX_REG_ALARM0_CTRL	0x0d
 667#define MCP794XX_REG_ALARM1_BASE	0x11
 668#define MCP794XX_REG_ALARM1_CTRL	0x14
 669#	define MCP794XX_BIT_ALMX_IF	(1 << 3)
 670#	define MCP794XX_BIT_ALMX_C0	(1 << 4)
 671#	define MCP794XX_BIT_ALMX_C1	(1 << 5)
 672#	define MCP794XX_BIT_ALMX_C2	(1 << 6)
 673#	define MCP794XX_BIT_ALMX_POL	(1 << 7)
 674#	define MCP794XX_MSK_ALMX_MATCH	(MCP794XX_BIT_ALMX_C0 | \
 675					 MCP794XX_BIT_ALMX_C1 | \
 676					 MCP794XX_BIT_ALMX_C2)
 677
 678static irqreturn_t mcp794xx_irq(int irq, void *dev_id)
 679{
 680	struct i2c_client       *client = dev_id;
 681	struct ds1307           *ds1307 = i2c_get_clientdata(client);
 682	struct mutex            *lock = &ds1307->rtc->ops_lock;
 683	int reg, ret;
 684
 685	mutex_lock(lock);
 686
 687	/* Check and clear alarm 0 interrupt flag. */
 688	reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
 689	if (reg < 0)
 690		goto out;
 691	if (!(reg & MCP794XX_BIT_ALMX_IF))
 692		goto out;
 693	reg &= ~MCP794XX_BIT_ALMX_IF;
 694	ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
 695	if (ret < 0)
 696		goto out;
 697
 698	/* Disable alarm 0. */
 699	reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
 700	if (reg < 0)
 701		goto out;
 702	reg &= ~MCP794XX_BIT_ALM0_EN;
 703	ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
 704	if (ret < 0)
 705		goto out;
 706
 707	rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
 708
 709out:
 710	mutex_unlock(lock);
 711
 712	return IRQ_HANDLED;
 713}
 714
 715static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
 716{
 717	struct i2c_client *client = to_i2c_client(dev);
 718	struct ds1307 *ds1307 = i2c_get_clientdata(client);
 719	u8 *regs = ds1307->regs;
 720	int ret;
 721
 722	if (!test_bit(HAS_ALARM, &ds1307->flags))
 723		return -EINVAL;
 724
 725	/* Read control and alarm 0 registers. */
 726	ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
 727	if (ret < 0)
 728		return ret;
 729
 730	t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);
 731
 732	/* Report alarm 0 time assuming 24-hour and day-of-month modes. */
 733	t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
 734	t->time.tm_min = bcd2bin(ds1307->regs[4] & 0x7f);
 735	t->time.tm_hour = bcd2bin(ds1307->regs[5] & 0x3f);
 736	t->time.tm_wday = bcd2bin(ds1307->regs[6] & 0x7) - 1;
 737	t->time.tm_mday = bcd2bin(ds1307->regs[7] & 0x3f);
 738	t->time.tm_mon = bcd2bin(ds1307->regs[8] & 0x1f) - 1;
 739	t->time.tm_year = -1;
 740	t->time.tm_yday = -1;
 741	t->time.tm_isdst = -1;
 742
 743	dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 744		"enabled=%d polarity=%d irq=%d match=%d\n", __func__,
 745		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 746		t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
 747		!!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
 748		!!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
 749		(ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);
 750
 751	return 0;
 752}
 753
 754static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 755{
 756	struct i2c_client *client = to_i2c_client(dev);
 757	struct ds1307 *ds1307 = i2c_get_clientdata(client);
 758	unsigned char *regs = ds1307->regs;
 759	int ret;
 760
 761	if (!test_bit(HAS_ALARM, &ds1307->flags))
 762		return -EINVAL;
 763
 764	dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d "
 765		"enabled=%d pending=%d\n", __func__,
 766		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
 767		t->time.tm_wday, t->time.tm_mday, t->time.tm_mon,
 768		t->enabled, t->pending);
 769
 770	/* Read control and alarm 0 registers. */
 771	ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
 772	if (ret < 0)
 773		return ret;
 774
 775	/* Set alarm 0, using 24-hour and day-of-month modes. */
 776	regs[3] = bin2bcd(t->time.tm_sec);
 777	regs[4] = bin2bcd(t->time.tm_min);
 778	regs[5] = bin2bcd(t->time.tm_hour);
 779	regs[6] = bin2bcd(t->time.tm_wday + 1);
 780	regs[7] = bin2bcd(t->time.tm_mday);
 781	regs[8] = bin2bcd(t->time.tm_mon + 1);
 782
 783	/* Clear the alarm 0 interrupt flag. */
 784	regs[6] &= ~MCP794XX_BIT_ALMX_IF;
 785	/* Set alarm match: second, minute, hour, day, date, month. */
 786	regs[6] |= MCP794XX_MSK_ALMX_MATCH;
 787	/* Disable interrupt. We will not enable until completely programmed */
 788	regs[0] &= ~MCP794XX_BIT_ALM0_EN;
 789
 790	ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
 791	if (ret < 0)
 792		return ret;
 793
 794	if (!t->enabled)
 795		return 0;
 796	regs[0] |= MCP794XX_BIT_ALM0_EN;
 797	return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, regs[0]);
 798}
 799
 800static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
 801{
 802	struct i2c_client *client = to_i2c_client(dev);
 803	struct ds1307 *ds1307 = i2c_get_clientdata(client);
 804	int reg;
 805
 806	if (!test_bit(HAS_ALARM, &ds1307->flags))
 807		return -EINVAL;
 808
 809	reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
 810	if (reg < 0)
 811		return reg;
 812
 813	if (enabled)
 814		reg |= MCP794XX_BIT_ALM0_EN;
 815	else
 816		reg &= ~MCP794XX_BIT_ALM0_EN;
 817
 818	return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
 819}
 820
 821static const struct rtc_class_ops mcp794xx_rtc_ops = {
 822	.read_time	= ds1307_get_time,
 823	.set_time	= ds1307_set_time,
 824	.read_alarm	= mcp794xx_read_alarm,
 825	.set_alarm	= mcp794xx_set_alarm,
 826	.alarm_irq_enable = mcp794xx_alarm_irq_enable,
 827};
 828
 829/*----------------------------------------------------------------------*/
 830
 831static ssize_t
 832ds1307_nvram_read(struct file *filp, struct kobject *kobj,
 833		struct bin_attribute *attr,
 834		char *buf, loff_t off, size_t count)
 835{
 836	struct i2c_client	*client;
 837	struct ds1307		*ds1307;
 838	int			result;
 839
 840	client = kobj_to_i2c_client(kobj);
 841	ds1307 = i2c_get_clientdata(client);
 842
 843	result = ds1307->read_block_data(client, ds1307->nvram_offset + off,
 844								count, buf);
 
 
 
 
 
 
 845	if (result < 0)
 846		dev_err(&client->dev, "%s error %d\n", "nvram read", result);
 847	return result;
 848}
 849
 850static ssize_t
 851ds1307_nvram_write(struct file *filp, struct kobject *kobj,
 852		struct bin_attribute *attr,
 853		char *buf, loff_t off, size_t count)
 854{
 855	struct i2c_client	*client;
 856	struct ds1307		*ds1307;
 857	int			result;
 858
 859	client = kobj_to_i2c_client(kobj);
 860	ds1307 = i2c_get_clientdata(client);
 861
 862	result = ds1307->write_block_data(client, ds1307->nvram_offset + off,
 863								count, buf);
 
 
 
 
 
 
 864	if (result < 0) {
 865		dev_err(&client->dev, "%s error %d\n", "nvram write", result);
 866		return result;
 867	}
 868	return count;
 869}
 870
 
 
 
 
 
 871
 872/*----------------------------------------------------------------------*/
 873
 874static u8 do_trickle_setup_ds1339(struct i2c_client *client,
 875				  uint32_t ohms, bool diode)
 876{
 877	u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE :
 878		DS1307_TRICKLE_CHARGER_NO_DIODE;
 879
 880	switch (ohms) {
 881	case 250:
 882		setup |= DS1307_TRICKLE_CHARGER_250_OHM;
 883		break;
 884	case 2000:
 885		setup |= DS1307_TRICKLE_CHARGER_2K_OHM;
 886		break;
 887	case 4000:
 888		setup |= DS1307_TRICKLE_CHARGER_4K_OHM;
 889		break;
 890	default:
 891		dev_warn(&client->dev,
 892			 "Unsupported ohm value %u in dt\n", ohms);
 893		return 0;
 894	}
 895	return setup;
 896}
 897
 898static void ds1307_trickle_init(struct i2c_client *client,
 899				struct chip_desc *chip)
 900{
 901	uint32_t ohms = 0;
 902	bool diode = true;
 903
 904	if (!chip->do_trickle_setup)
 905		goto out;
 906	if (device_property_read_u32(&client->dev, "trickle-resistor-ohms", &ohms))
 907		goto out;
 908	if (device_property_read_bool(&client->dev, "trickle-diode-disable"))
 909		diode = false;
 910	chip->trickle_charger_setup = chip->do_trickle_setup(client,
 911							     ohms, diode);
 912out:
 913	return;
 914}
 915
 916/*----------------------------------------------------------------------*/
 917
 918#ifdef CONFIG_RTC_DRV_DS1307_HWMON
 919
 920/*
 921 * Temperature sensor support for ds3231 devices.
 922 */
 923
 924#define DS3231_REG_TEMPERATURE	0x11
 925
 926/*
 927 * A user-initiated temperature conversion is not started by this function,
 928 * so the temperature is updated once every 64 seconds.
 929 */
 930static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC)
 931{
 932	struct ds1307 *ds1307 = dev_get_drvdata(dev);
 933	u8 temp_buf[2];
 934	s16 temp;
 935	int ret;
 936
 937	ret = ds1307->read_block_data(ds1307->client, DS3231_REG_TEMPERATURE,
 938					sizeof(temp_buf), temp_buf);
 939	if (ret < 0)
 940		return ret;
 941	if (ret != sizeof(temp_buf))
 942		return -EIO;
 943
 944	/*
 945	 * Temperature is represented as a 10-bit code with a resolution of
 946	 * 0.25 degree celsius and encoded in two's complement format.
 947	 */
 948	temp = (temp_buf[0] << 8) | temp_buf[1];
 949	temp >>= 6;
 950	*mC = temp * 250;
 951
 952	return 0;
 953}
 954
 955static ssize_t ds3231_hwmon_show_temp(struct device *dev,
 956				struct device_attribute *attr, char *buf)
 957{
 958	int ret;
 959	s32 temp;
 960
 961	ret = ds3231_hwmon_read_temp(dev, &temp);
 962	if (ret)
 963		return ret;
 964
 965	return sprintf(buf, "%d\n", temp);
 966}
 967static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ds3231_hwmon_show_temp,
 968			NULL, 0);
 969
 970static struct attribute *ds3231_hwmon_attrs[] = {
 971	&sensor_dev_attr_temp1_input.dev_attr.attr,
 972	NULL,
 973};
 974ATTRIBUTE_GROUPS(ds3231_hwmon);
 975
 976static void ds1307_hwmon_register(struct ds1307 *ds1307)
 977{
 978	struct device *dev;
 979
 980	if (ds1307->type != ds_3231)
 981		return;
 982
 983	dev = devm_hwmon_device_register_with_groups(&ds1307->client->dev,
 984						ds1307->client->name,
 985						ds1307, ds3231_hwmon_groups);
 986	if (IS_ERR(dev)) {
 987		dev_warn(&ds1307->client->dev,
 988			"unable to register hwmon device %ld\n", PTR_ERR(dev));
 989	}
 990}
 991
 992#else
 993
 994static void ds1307_hwmon_register(struct ds1307 *ds1307)
 995{
 996}
 997
 998#endif /* CONFIG_RTC_DRV_DS1307_HWMON */
 999
1000/*----------------------------------------------------------------------*/
1001
1002/*
1003 * Square-wave output support for DS3231
1004 * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf
1005 */
1006#ifdef CONFIG_COMMON_CLK
1007
1008enum {
1009	DS3231_CLK_SQW = 0,
1010	DS3231_CLK_32KHZ,
1011};
1012
1013#define clk_sqw_to_ds1307(clk)	\
1014	container_of(clk, struct ds1307, clks[DS3231_CLK_SQW])
1015#define clk_32khz_to_ds1307(clk)	\
1016	container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ])
1017
1018static int ds3231_clk_sqw_rates[] = {
1019	1,
1020	1024,
1021	4096,
1022	8192,
1023};
1024
1025static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value)
1026{
1027	struct i2c_client *client = ds1307->client;
1028	struct mutex *lock = &ds1307->rtc->ops_lock;
1029	int control;
1030	int ret;
1031
1032	mutex_lock(lock);
1033
1034	control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
1035	if (control < 0) {
1036		ret = control;
1037		goto out;
1038	}
1039
1040	control &= ~mask;
1041	control |= value;
1042
1043	ret = i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
1044out:
1045	mutex_unlock(lock);
1046
1047	return ret;
1048}
1049
1050static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw,
1051						unsigned long parent_rate)
1052{
1053	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1054	int control;
1055	int rate_sel = 0;
1056
1057	control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
1058	if (control < 0)
1059		return control;
1060	if (control & DS1337_BIT_RS1)
1061		rate_sel += 1;
1062	if (control & DS1337_BIT_RS2)
1063		rate_sel += 2;
1064
1065	return ds3231_clk_sqw_rates[rate_sel];
1066}
1067
1068static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
1069					unsigned long *prate)
1070{
1071	int i;
1072
1073	for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) {
1074		if (ds3231_clk_sqw_rates[i] <= rate)
1075			return ds3231_clk_sqw_rates[i];
1076	}
1077
1078	return 0;
1079}
1080
1081static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
1082					unsigned long parent_rate)
1083{
1084	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1085	int control = 0;
1086	int rate_sel;
1087
1088	for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates);
1089			rate_sel++) {
1090		if (ds3231_clk_sqw_rates[rate_sel] == rate)
1091			break;
1092	}
1093
1094	if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates))
1095		return -EINVAL;
1096
1097	if (rate_sel & 1)
1098		control |= DS1337_BIT_RS1;
1099	if (rate_sel & 2)
1100		control |= DS1337_BIT_RS2;
1101
1102	return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2,
1103				control);
1104}
1105
1106static int ds3231_clk_sqw_prepare(struct clk_hw *hw)
1107{
1108	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1109
1110	return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0);
1111}
1112
1113static void ds3231_clk_sqw_unprepare(struct clk_hw *hw)
1114{
1115	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1116
1117	ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN);
1118}
1119
1120static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw)
1121{
1122	struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw);
1123	int control;
1124
1125	control = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_CONTROL);
1126	if (control < 0)
1127		return control;
1128
1129	return !(control & DS1337_BIT_INTCN);
1130}
1131
1132static const struct clk_ops ds3231_clk_sqw_ops = {
1133	.prepare = ds3231_clk_sqw_prepare,
1134	.unprepare = ds3231_clk_sqw_unprepare,
1135	.is_prepared = ds3231_clk_sqw_is_prepared,
1136	.recalc_rate = ds3231_clk_sqw_recalc_rate,
1137	.round_rate = ds3231_clk_sqw_round_rate,
1138	.set_rate = ds3231_clk_sqw_set_rate,
1139};
1140
1141static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw,
1142						unsigned long parent_rate)
1143{
1144	return 32768;
1145}
1146
1147static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable)
1148{
1149	struct i2c_client *client = ds1307->client;
1150	struct mutex *lock = &ds1307->rtc->ops_lock;
1151	int status;
1152	int ret;
1153
1154	mutex_lock(lock);
1155
1156	status = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
1157	if (status < 0) {
1158		ret = status;
1159		goto out;
1160	}
1161
1162	if (enable)
1163		status |= DS3231_BIT_EN32KHZ;
1164	else
1165		status &= ~DS3231_BIT_EN32KHZ;
1166
1167	ret = i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, status);
1168out:
1169	mutex_unlock(lock);
1170
1171	return ret;
1172}
1173
1174static int ds3231_clk_32khz_prepare(struct clk_hw *hw)
1175{
1176	struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1177
1178	return ds3231_clk_32khz_control(ds1307, true);
1179}
1180
1181static void ds3231_clk_32khz_unprepare(struct clk_hw *hw)
1182{
1183	struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1184
1185	ds3231_clk_32khz_control(ds1307, false);
1186}
1187
1188static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw)
1189{
1190	struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw);
1191	int status;
1192
1193	status = i2c_smbus_read_byte_data(ds1307->client, DS1337_REG_STATUS);
1194	if (status < 0)
1195		return status;
1196
1197	return !!(status & DS3231_BIT_EN32KHZ);
1198}
1199
1200static const struct clk_ops ds3231_clk_32khz_ops = {
1201	.prepare = ds3231_clk_32khz_prepare,
1202	.unprepare = ds3231_clk_32khz_unprepare,
1203	.is_prepared = ds3231_clk_32khz_is_prepared,
1204	.recalc_rate = ds3231_clk_32khz_recalc_rate,
1205};
1206
1207static struct clk_init_data ds3231_clks_init[] = {
1208	[DS3231_CLK_SQW] = {
1209		.name = "ds3231_clk_sqw",
1210		.ops = &ds3231_clk_sqw_ops,
1211	},
1212	[DS3231_CLK_32KHZ] = {
1213		.name = "ds3231_clk_32khz",
1214		.ops = &ds3231_clk_32khz_ops,
1215	},
1216};
1217
1218static int ds3231_clks_register(struct ds1307 *ds1307)
1219{
1220	struct i2c_client *client = ds1307->client;
1221	struct device_node *node = client->dev.of_node;
1222	struct clk_onecell_data	*onecell;
1223	int i;
1224
1225	onecell = devm_kzalloc(&client->dev, sizeof(*onecell), GFP_KERNEL);
1226	if (!onecell)
1227		return -ENOMEM;
1228
1229	onecell->clk_num = ARRAY_SIZE(ds3231_clks_init);
1230	onecell->clks = devm_kcalloc(&client->dev, onecell->clk_num,
1231					sizeof(onecell->clks[0]), GFP_KERNEL);
1232	if (!onecell->clks)
1233		return -ENOMEM;
1234
1235	for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) {
1236		struct clk_init_data init = ds3231_clks_init[i];
1237
1238		/*
1239		 * Interrupt signal due to alarm conditions and square-wave
1240		 * output share same pin, so don't initialize both.
1241		 */
1242		if (i == DS3231_CLK_SQW && test_bit(HAS_ALARM, &ds1307->flags))
1243			continue;
1244
1245		/* optional override of the clockname */
1246		of_property_read_string_index(node, "clock-output-names", i,
1247						&init.name);
1248		ds1307->clks[i].init = &init;
1249
1250		onecell->clks[i] = devm_clk_register(&client->dev,
1251							&ds1307->clks[i]);
1252		if (IS_ERR(onecell->clks[i]))
1253			return PTR_ERR(onecell->clks[i]);
1254	}
1255
1256	if (!node)
1257		return 0;
1258
1259	of_clk_add_provider(node, of_clk_src_onecell_get, onecell);
1260
1261	return 0;
1262}
1263
1264static void ds1307_clks_register(struct ds1307 *ds1307)
1265{
1266	int ret;
1267
1268	if (ds1307->type != ds_3231)
1269		return;
1270
1271	ret = ds3231_clks_register(ds1307);
1272	if (ret) {
1273		dev_warn(&ds1307->client->dev,
1274			"unable to register clock device %d\n", ret);
1275	}
1276}
1277
1278#else
1279
1280static void ds1307_clks_register(struct ds1307 *ds1307)
1281{
1282}
1283
1284#endif /* CONFIG_COMMON_CLK */
1285
1286static int ds1307_probe(struct i2c_client *client,
1287			const struct i2c_device_id *id)
1288{
1289	struct ds1307		*ds1307;
1290	int			err = -ENODEV;
1291	int			tmp, wday;
1292	struct chip_desc	*chip;
1293	struct i2c_adapter	*adapter = to_i2c_adapter(client->dev.parent);
1294	bool			want_irq = false;
1295	bool			ds1307_can_wakeup_device = false;
1296	unsigned char		*buf;
1297	struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
1298	struct rtc_time		tm;
1299	unsigned long		timestamp;
1300
1301	irq_handler_t	irq_handler = ds1307_irq;
1302
1303	static const int	bbsqi_bitpos[] = {
1304		[ds_1337] = 0,
1305		[ds_1339] = DS1339_BIT_BBSQI,
1306		[ds_3231] = DS3231_BIT_BBSQW,
1307	};
1308	const struct rtc_class_ops *rtc_ops = &ds13xx_rtc_ops;
1309
1310	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)
1311	    && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
1312		return -EIO;
1313
1314	ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL);
1315	if (!ds1307)
1316		return -ENOMEM;
1317
1318	i2c_set_clientdata(client, ds1307);
1319
1320	ds1307->client	= client;
1321	if (id) {
1322		chip = &chips[id->driver_data];
1323		ds1307->type = id->driver_data;
1324	} else {
1325		const struct acpi_device_id *acpi_id;
1326
1327		acpi_id = acpi_match_device(ACPI_PTR(ds1307_acpi_ids),
1328					    &client->dev);
1329		if (!acpi_id)
1330			return -ENODEV;
1331		chip = &chips[acpi_id->driver_data];
1332		ds1307->type = acpi_id->driver_data;
1333	}
1334
1335	if (!pdata)
1336		ds1307_trickle_init(client, chip);
1337	else if (pdata->trickle_charger_setup)
1338		chip->trickle_charger_setup = pdata->trickle_charger_setup;
1339
1340	if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
1341		dev_dbg(&client->dev, "writing trickle charger info 0x%x to 0x%x\n",
1342		    DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
1343		    chip->trickle_charger_reg);
1344		i2c_smbus_write_byte_data(client, chip->trickle_charger_reg,
1345		    DS13XX_TRICKLE_CHARGER_MAGIC |
1346		    chip->trickle_charger_setup);
1347	}
1348
1349	buf = ds1307->regs;
1350	if (i2c_check_functionality(adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
1351		ds1307->read_block_data = ds1307_native_smbus_read_block_data;
1352		ds1307->write_block_data = ds1307_native_smbus_write_block_data;
1353	} else {
1354		ds1307->read_block_data = ds1307_read_block_data;
1355		ds1307->write_block_data = ds1307_write_block_data;
1356	}
1357
1358#ifdef CONFIG_OF
1359/*
1360 * For devices with no IRQ directly connected to the SoC, the RTC chip
1361 * can be forced as a wakeup source by stating that explicitly in
1362 * the device's .dts file using the "wakeup-source" boolean property.
1363 * If the "wakeup-source" property is set, don't request an IRQ.
1364 * This will guarantee the 'wakealarm' sysfs entry is available on the device,
1365 * if supported by the RTC.
1366 */
1367	if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
1368		ds1307_can_wakeup_device = true;
1369	}
1370	/* Intersil ISL12057 DT backward compatibility */
1371	if (of_property_read_bool(client->dev.of_node,
1372				  "isil,irq2-can-wakeup-machine")) {
1373		ds1307_can_wakeup_device = true;
1374	}
1375#endif
1376
1377	switch (ds1307->type) {
1378	case ds_1337:
1379	case ds_1339:
1380	case ds_3231:
 
 
 
 
 
1381		/* get registers that the "rtc" read below won't read... */
1382		tmp = ds1307->read_block_data(ds1307->client,
1383				DS1337_REG_CONTROL, 2, buf);
1384		if (tmp != 2) {
1385			dev_dbg(&client->dev, "read error %d\n", tmp);
1386			err = -EIO;
1387			goto exit;
1388		}
1389
1390		/* oscillator off?  turn it on, so clock can tick. */
1391		if (ds1307->regs[0] & DS1337_BIT_nEOSC)
1392			ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
1393
1394		/*
1395		 * Using IRQ or defined as wakeup-source?
1396		 * Disable the square wave and both alarms.
1397		 * For some variants, be sure alarms can trigger when we're
1398		 * running on Vbackup (BBSQI/BBSQW)
1399		 */
1400		if (chip->alarm && (ds1307->client->irq > 0 ||
1401						ds1307_can_wakeup_device)) {
1402			ds1307->regs[0] |= DS1337_BIT_INTCN
1403					| bbsqi_bitpos[ds1307->type];
1404			ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
1405
1406			want_irq = true;
1407		}
1408
1409		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
1410							ds1307->regs[0]);
1411
1412		/* oscillator fault?  clear flag, and warn */
1413		if (ds1307->regs[1] & DS1337_BIT_OSF) {
1414			i2c_smbus_write_byte_data(client, DS1337_REG_STATUS,
1415				ds1307->regs[1] & ~DS1337_BIT_OSF);
1416			dev_warn(&client->dev, "SET TIME!\n");
1417		}
1418		break;
1419
1420	case rx_8025:
1421		tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1422				RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1423		if (tmp != 2) {
1424			dev_dbg(&client->dev, "read error %d\n", tmp);
1425			err = -EIO;
1426			goto exit;
1427		}
1428
1429		/* oscillator off?  turn it on, so clock can tick. */
1430		if (!(ds1307->regs[1] & RX8025_BIT_XST)) {
1431			ds1307->regs[1] |= RX8025_BIT_XST;
1432			i2c_smbus_write_byte_data(client,
1433						  RX8025_REG_CTRL2 << 4 | 0x08,
1434						  ds1307->regs[1]);
1435			dev_warn(&client->dev,
1436				 "oscillator stop detected - SET TIME!\n");
1437		}
1438
1439		if (ds1307->regs[1] & RX8025_BIT_PON) {
1440			ds1307->regs[1] &= ~RX8025_BIT_PON;
1441			i2c_smbus_write_byte_data(client,
1442						  RX8025_REG_CTRL2 << 4 | 0x08,
1443						  ds1307->regs[1]);
1444			dev_warn(&client->dev, "power-on detected\n");
1445		}
1446
1447		if (ds1307->regs[1] & RX8025_BIT_VDET) {
1448			ds1307->regs[1] &= ~RX8025_BIT_VDET;
1449			i2c_smbus_write_byte_data(client,
1450						  RX8025_REG_CTRL2 << 4 | 0x08,
1451						  ds1307->regs[1]);
1452			dev_warn(&client->dev, "voltage drop detected\n");
1453		}
1454
1455		/* make sure we are running in 24hour mode */
1456		if (!(ds1307->regs[0] & RX8025_BIT_2412)) {
1457			u8 hour;
1458
1459			/* switch to 24 hour mode */
1460			i2c_smbus_write_byte_data(client,
1461						  RX8025_REG_CTRL1 << 4 | 0x08,
1462						  ds1307->regs[0] |
1463						  RX8025_BIT_2412);
1464
1465			tmp = i2c_smbus_read_i2c_block_data(ds1307->client,
1466					RX8025_REG_CTRL1 << 4 | 0x08, 2, buf);
1467			if (tmp != 2) {
1468				dev_dbg(&client->dev, "read error %d\n", tmp);
1469				err = -EIO;
1470				goto exit;
1471			}
1472
1473			/* correct hour */
1474			hour = bcd2bin(ds1307->regs[DS1307_REG_HOUR]);
1475			if (hour == 12)
1476				hour = 0;
1477			if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1478				hour += 12;
1479
1480			i2c_smbus_write_byte_data(client,
1481						  DS1307_REG_HOUR << 4 | 0x08,
1482						  hour);
1483		}
1484		break;
1485	case ds_1388:
1486		ds1307->offset = 1; /* Seconds starts at 1 */
1487		break;
1488	case mcp794xx:
1489		rtc_ops = &mcp794xx_rtc_ops;
1490		if (ds1307->client->irq > 0 && chip->alarm) {
1491			irq_handler = mcp794xx_irq;
1492			want_irq = true;
1493		}
1494		break;
1495	default:
1496		break;
1497	}
1498
1499read_rtc:
1500	/* read RTC registers */
1501	tmp = ds1307->read_block_data(ds1307->client, ds1307->offset, 8, buf);
1502	if (tmp != 8) {
1503		dev_dbg(&client->dev, "read error %d\n", tmp);
1504		err = -EIO;
1505		goto exit;
1506	}
1507
1508	/*
1509	 * minimal sanity checking; some chips (like DS1340) don't
1510	 * specify the extra bits as must-be-zero, but there are
1511	 * still a few values that are clearly out-of-range.
1512	 */
1513	tmp = ds1307->regs[DS1307_REG_SECS];
1514	switch (ds1307->type) {
1515	case ds_1307:
1516	case m41t00:
1517		/* clock halted?  turn it on, so clock can tick. */
1518		if (tmp & DS1307_BIT_CH) {
1519			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1520			dev_warn(&client->dev, "SET TIME!\n");
1521			goto read_rtc;
1522		}
1523		break;
1524	case ds_1338:
1525		/* clock halted?  turn it on, so clock can tick. */
1526		if (tmp & DS1307_BIT_CH)
1527			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1528
1529		/* oscillator fault?  clear flag, and warn */
1530		if (ds1307->regs[DS1307_REG_CONTROL] & DS1338_BIT_OSF) {
1531			i2c_smbus_write_byte_data(client, DS1307_REG_CONTROL,
1532					ds1307->regs[DS1307_REG_CONTROL]
1533					& ~DS1338_BIT_OSF);
1534			dev_warn(&client->dev, "SET TIME!\n");
1535			goto read_rtc;
1536		}
1537		break;
1538	case ds_1340:
1539		/* clock halted?  turn it on, so clock can tick. */
1540		if (tmp & DS1340_BIT_nEOSC)
1541			i2c_smbus_write_byte_data(client, DS1307_REG_SECS, 0);
1542
1543		tmp = i2c_smbus_read_byte_data(client, DS1340_REG_FLAG);
1544		if (tmp < 0) {
1545			dev_dbg(&client->dev, "read error %d\n", tmp);
1546			err = -EIO;
1547			goto exit;
1548		}
1549
1550		/* oscillator fault?  clear flag, and warn */
1551		if (tmp & DS1340_BIT_OSF) {
1552			i2c_smbus_write_byte_data(client, DS1340_REG_FLAG, 0);
1553			dev_warn(&client->dev, "SET TIME!\n");
1554		}
1555		break;
1556	case mcp794xx:
1557		/* make sure that the backup battery is enabled */
1558		if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
1559			i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
1560					ds1307->regs[DS1307_REG_WDAY]
1561					| MCP794XX_BIT_VBATEN);
1562		}
1563
1564		/* clock halted?  turn it on, so clock can tick. */
1565		if (!(tmp & MCP794XX_BIT_ST)) {
1566			i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
1567					MCP794XX_BIT_ST);
1568			dev_warn(&client->dev, "SET TIME!\n");
1569			goto read_rtc;
1570		}
1571
1572		break;
1573	default:
1574		break;
1575	}
1576
1577	tmp = ds1307->regs[DS1307_REG_HOUR];
1578	switch (ds1307->type) {
1579	case ds_1340:
1580	case m41t00:
1581		/*
1582		 * NOTE: ignores century bits; fix before deploying
1583		 * systems that will run through year 2100.
1584		 */
1585		break;
1586	case rx_8025:
1587		break;
1588	default:
1589		if (!(tmp & DS1307_BIT_12HR))
1590			break;
1591
1592		/*
1593		 * Be sure we're in 24 hour mode.  Multi-master systems
1594		 * take note...
1595		 */
1596		tmp = bcd2bin(tmp & 0x1f);
1597		if (tmp == 12)
1598			tmp = 0;
1599		if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM)
1600			tmp += 12;
1601		i2c_smbus_write_byte_data(client,
1602				ds1307->offset + DS1307_REG_HOUR,
1603				bin2bcd(tmp));
1604	}
1605
1606	/*
1607	 * Some IPs have weekday reset value = 0x1 which might not correct
1608	 * hence compute the wday using the current date/month/year values
1609	 */
1610	ds1307_get_time(&client->dev, &tm);
1611	wday = tm.tm_wday;
1612	timestamp = rtc_tm_to_time64(&tm);
1613	rtc_time64_to_tm(timestamp, &tm);
1614
1615	/*
1616	 * Check if reset wday is different from the computed wday
1617	 * If different then set the wday which we computed using
1618	 * timestamp
1619	 */
1620	if (wday != tm.tm_wday) {
1621		wday = i2c_smbus_read_byte_data(client, MCP794XX_REG_WEEKDAY);
1622		wday = wday & ~MCP794XX_REG_WEEKDAY_WDAY_MASK;
1623		wday = wday | (tm.tm_wday + 1);
1624		i2c_smbus_write_byte_data(client, MCP794XX_REG_WEEKDAY, wday);
1625	}
1626
1627	if (want_irq) {
1628		device_set_wakeup_capable(&client->dev, true);
1629		set_bit(HAS_ALARM, &ds1307->flags);
1630	}
1631	ds1307->rtc = devm_rtc_device_register(&client->dev, client->name,
1632				rtc_ops, THIS_MODULE);
1633	if (IS_ERR(ds1307->rtc)) {
1634		return PTR_ERR(ds1307->rtc);
1635	}
1636
1637	if (ds1307_can_wakeup_device && ds1307->client->irq <= 0) {
1638		/* Disable request for an IRQ */
1639		want_irq = false;
1640		dev_info(&client->dev, "'wakeup-source' is set, request for an IRQ is disabled!\n");
1641		/* We cannot support UIE mode if we do not have an IRQ line */
1642		ds1307->rtc->uie_unsupported = 1;
1643	}
1644
1645	if (want_irq) {
1646		err = devm_request_threaded_irq(&client->dev,
1647						client->irq, NULL, irq_handler,
1648						IRQF_SHARED | IRQF_ONESHOT,
1649						ds1307->rtc->name, client);
1650		if (err) {
1651			client->irq = 0;
1652			device_set_wakeup_capable(&client->dev, false);
1653			clear_bit(HAS_ALARM, &ds1307->flags);
1654			dev_err(&client->dev, "unable to request IRQ!\n");
1655		} else
1656			dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
 
 
1657	}
1658
1659	if (chip->nvram_size) {
1660
1661		ds1307->nvram = devm_kzalloc(&client->dev,
1662					sizeof(struct bin_attribute),
1663					GFP_KERNEL);
1664		if (!ds1307->nvram) {
1665			dev_err(&client->dev, "cannot allocate memory for nvram sysfs\n");
1666		} else {
1667
1668			ds1307->nvram->attr.name = "nvram";
1669			ds1307->nvram->attr.mode = S_IRUGO | S_IWUSR;
1670
1671			sysfs_bin_attr_init(ds1307->nvram);
1672
1673			ds1307->nvram->read = ds1307_nvram_read;
1674			ds1307->nvram->write = ds1307_nvram_write;
1675			ds1307->nvram->size = chip->nvram_size;
1676			ds1307->nvram_offset = chip->nvram_offset;
1677
1678			err = sysfs_create_bin_file(&client->dev.kobj,
1679						    ds1307->nvram);
1680			if (err) {
1681				dev_err(&client->dev,
1682					"unable to create sysfs file: %s\n",
1683					ds1307->nvram->attr.name);
1684			} else {
1685				set_bit(HAS_NVRAM, &ds1307->flags);
1686				dev_info(&client->dev, "%zu bytes nvram\n",
1687					 ds1307->nvram->size);
1688			}
1689		}
1690	}
1691
1692	ds1307_hwmon_register(ds1307);
1693	ds1307_clks_register(ds1307);
1694
1695	return 0;
1696
1697exit:
 
 
 
1698	return err;
1699}
1700
1701static int ds1307_remove(struct i2c_client *client)
1702{
1703	struct ds1307 *ds1307 = i2c_get_clientdata(client);
 
 
 
 
 
1704
1705	if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
1706		sysfs_remove_bin_file(&client->dev.kobj, ds1307->nvram);
1707
 
 
1708	return 0;
1709}
1710
1711static struct i2c_driver ds1307_driver = {
1712	.driver = {
1713		.name	= "rtc-ds1307",
1714		.acpi_match_table = ACPI_PTR(ds1307_acpi_ids),
1715	},
1716	.probe		= ds1307_probe,
1717	.remove		= ds1307_remove,
1718	.id_table	= ds1307_id,
1719};
1720
1721module_i2c_driver(ds1307_driver);
 
 
 
 
 
 
 
 
 
 
1722
1723MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips");
1724MODULE_LICENSE("GPL");