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v4.6
  1/*
  2 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
  3 *
  4 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
  5 * Copyright (C) 2006 Tower Technologies
  6 * Copyright (C) 2008 Paul Mundt
  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/i2c.h>
 14#include <linux/rtc.h>
 15#include <linux/bcd.h>
 16#include <linux/slab.h>
 17#include <linux/module.h>
 18
 19#define DRV_VERSION "0.6"
 20
 21
 22/*
 23 * Ricoh has a family of I2C based RTCs, which differ only slightly from
 24 * each other.  Differences center on pinout (e.g. how many interrupts,
 25 * output clock, etc) and how the control registers are used.  The '372
 26 * is significant only because that's the one this driver first supported.
 27 */
 28#define RS5C372_REG_SECS	0
 29#define RS5C372_REG_MINS	1
 30#define RS5C372_REG_HOURS	2
 31#define RS5C372_REG_WDAY	3
 32#define RS5C372_REG_DAY		4
 33#define RS5C372_REG_MONTH	5
 34#define RS5C372_REG_YEAR	6
 35#define RS5C372_REG_TRIM	7
 36#	define RS5C372_TRIM_XSL		0x80
 37#	define RS5C372_TRIM_MASK	0x7F
 38
 39#define RS5C_REG_ALARM_A_MIN	8			/* or ALARM_W */
 40#define RS5C_REG_ALARM_A_HOURS	9
 41#define RS5C_REG_ALARM_A_WDAY	10
 42
 43#define RS5C_REG_ALARM_B_MIN	11			/* or ALARM_D */
 44#define RS5C_REG_ALARM_B_HOURS	12
 45#define RS5C_REG_ALARM_B_WDAY	13			/* (ALARM_B only) */
 46
 47#define RS5C_REG_CTRL1		14
 48#	define RS5C_CTRL1_AALE		(1 << 7)	/* or WALE */
 49#	define RS5C_CTRL1_BALE		(1 << 6)	/* or DALE */
 50#	define RV5C387_CTRL1_24		(1 << 5)
 51#	define RS5C372A_CTRL1_SL1	(1 << 5)
 52#	define RS5C_CTRL1_CT_MASK	(7 << 0)
 53#	define RS5C_CTRL1_CT0		(0 << 0)	/* no periodic irq */
 54#	define RS5C_CTRL1_CT4		(4 << 0)	/* 1 Hz level irq */
 55#define RS5C_REG_CTRL2		15
 56#	define RS5C372_CTRL2_24		(1 << 5)
 57#	define R2025_CTRL2_XST		(1 << 5)
 58#	define RS5C_CTRL2_XSTP		(1 << 4)	/* only if !R2025S/D */
 59#	define RS5C_CTRL2_CTFG		(1 << 2)
 60#	define RS5C_CTRL2_AAFG		(1 << 1)	/* or WAFG */
 61#	define RS5C_CTRL2_BAFG		(1 << 0)	/* or DAFG */
 62
 63
 64/* to read (style 1) or write registers starting at R */
 65#define RS5C_ADDR(R)		(((R) << 4) | 0)
 66
 67
 68enum rtc_type {
 69	rtc_undef = 0,
 70	rtc_r2025sd,
 71	rtc_r2221tl,
 72	rtc_rs5c372a,
 73	rtc_rs5c372b,
 74	rtc_rv5c386,
 75	rtc_rv5c387a,
 76};
 77
 78static const struct i2c_device_id rs5c372_id[] = {
 79	{ "r2025sd", rtc_r2025sd },
 80	{ "r2221tl", rtc_r2221tl },
 81	{ "rs5c372a", rtc_rs5c372a },
 82	{ "rs5c372b", rtc_rs5c372b },
 83	{ "rv5c386", rtc_rv5c386 },
 84	{ "rv5c387a", rtc_rv5c387a },
 85	{ }
 86};
 87MODULE_DEVICE_TABLE(i2c, rs5c372_id);
 88
 89/* REVISIT:  this assumes that:
 90 *  - we're in the 21st century, so it's safe to ignore the century
 91 *    bit for rv5c38[67] (REG_MONTH bit 7);
 92 *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
 93 */
 94struct rs5c372 {
 95	struct i2c_client	*client;
 96	struct rtc_device	*rtc;
 97	enum rtc_type		type;
 98	unsigned		time24:1;
 99	unsigned		has_irq:1;
100	unsigned		smbus:1;
101	char			buf[17];
102	char			*regs;
103};
104
105static int rs5c_get_regs(struct rs5c372 *rs5c)
106{
107	struct i2c_client	*client = rs5c->client;
108	struct i2c_msg		msgs[] = {
109		{
110			.addr = client->addr,
111			.flags = I2C_M_RD,
112			.len = sizeof(rs5c->buf),
113			.buf = rs5c->buf
114		},
115	};
116
117	/* This implements the third reading method from the datasheet, using
118	 * an internal address that's reset after each transaction (by STOP)
119	 * to 0x0f ... so we read extra registers, and skip the first one.
120	 *
121	 * The first method doesn't work with the iop3xx adapter driver, on at
122	 * least 80219 chips; this works around that bug.
123	 *
124	 * The third method on the other hand doesn't work for the SMBus-only
125	 * configurations, so we use the the first method there, stripping off
126	 * the extra register in the process.
127	 */
128	if (rs5c->smbus) {
129		int addr = RS5C_ADDR(RS5C372_REG_SECS);
130		int size = sizeof(rs5c->buf) - 1;
131
132		if (i2c_smbus_read_i2c_block_data(client, addr, size,
133						  rs5c->buf + 1) != size) {
134			dev_warn(&client->dev, "can't read registers\n");
135			return -EIO;
136		}
137	} else {
138		if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
139			dev_warn(&client->dev, "can't read registers\n");
140			return -EIO;
141		}
142	}
143
144	dev_dbg(&client->dev,
145		"%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
146		rs5c->regs + 0, rs5c->regs[3],
147		rs5c->regs + 4, rs5c->regs[7],
148		rs5c->regs + 8, rs5c->regs + 11,
149		rs5c->regs[14], rs5c->regs[15]);
 
150
151	return 0;
152}
153
154static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
155{
156	unsigned	hour;
157
158	if (rs5c->time24)
159		return bcd2bin(reg & 0x3f);
160
161	hour = bcd2bin(reg & 0x1f);
162	if (hour == 12)
163		hour = 0;
164	if (reg & 0x20)
165		hour += 12;
166	return hour;
167}
168
169static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
170{
171	if (rs5c->time24)
172		return bin2bcd(hour);
173
174	if (hour > 12)
175		return 0x20 | bin2bcd(hour - 12);
176	if (hour == 12)
177		return 0x20 | bin2bcd(12);
178	if (hour == 0)
179		return bin2bcd(12);
180	return bin2bcd(hour);
181}
182
183static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
184{
185	struct rs5c372	*rs5c = i2c_get_clientdata(client);
186	int		status = rs5c_get_regs(rs5c);
187
188	if (status < 0)
189		return status;
190
191	tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
192	tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
193	tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
194
195	tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
196	tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
197
198	/* tm->tm_mon is zero-based */
199	tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
200
201	/* year is 1900 + tm->tm_year */
202	tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
203
204	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
205		"mday=%d, mon=%d, year=%d, wday=%d\n",
206		__func__,
207		tm->tm_sec, tm->tm_min, tm->tm_hour,
208		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
209
210	/* rtc might need initialization */
211	return rtc_valid_tm(tm);
212}
213
214static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
215{
216	struct rs5c372	*rs5c = i2c_get_clientdata(client);
217	unsigned char	buf[7];
218	int		addr;
219
220	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
221		"mday=%d, mon=%d, year=%d, wday=%d\n",
222		__func__,
223		tm->tm_sec, tm->tm_min, tm->tm_hour,
224		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
225
226	addr   = RS5C_ADDR(RS5C372_REG_SECS);
227	buf[0] = bin2bcd(tm->tm_sec);
228	buf[1] = bin2bcd(tm->tm_min);
229	buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
230	buf[3] = bin2bcd(tm->tm_wday);
231	buf[4] = bin2bcd(tm->tm_mday);
232	buf[5] = bin2bcd(tm->tm_mon + 1);
233	buf[6] = bin2bcd(tm->tm_year - 100);
234
235	if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
236		dev_err(&client->dev, "%s: write error\n", __func__);
237		return -EIO;
238	}
239
240	return 0;
241}
242
243#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
244#define	NEED_TRIM
245#endif
246
247#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
248#define	NEED_TRIM
249#endif
250
251#ifdef	NEED_TRIM
252static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
253{
254	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
255	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
256
257	if (osc)
258		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
259
260	if (trim) {
261		dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
262		tmp &= RS5C372_TRIM_MASK;
263		if (tmp & 0x3e) {
264			int t = tmp & 0x3f;
265
266			if (tmp & 0x40)
267				t = (~t | (s8)0xc0) + 1;
268			else
269				t = t - 1;
270
271			tmp = t * 2;
272		} else
273			tmp = 0;
274		*trim = tmp;
275	}
276
277	return 0;
278}
279#endif
280
281static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
282{
283	return rs5c372_get_datetime(to_i2c_client(dev), tm);
284}
285
286static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
287{
288	return rs5c372_set_datetime(to_i2c_client(dev), tm);
289}
290
291
292static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
293{
294	struct i2c_client	*client = to_i2c_client(dev);
295	struct rs5c372		*rs5c = i2c_get_clientdata(client);
296	unsigned char		buf;
297	int			status, addr;
298
299	buf = rs5c->regs[RS5C_REG_CTRL1];
300
301	if (!rs5c->has_irq)
302		return -EINVAL;
303
304	status = rs5c_get_regs(rs5c);
305	if (status < 0)
306		return status;
307
308	addr = RS5C_ADDR(RS5C_REG_CTRL1);
309	if (enabled)
310		buf |= RS5C_CTRL1_AALE;
311	else
312		buf &= ~RS5C_CTRL1_AALE;
313
314	if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
315		dev_warn(dev, "can't update alarm\n");
316		status = -EIO;
317	} else
318		rs5c->regs[RS5C_REG_CTRL1] = buf;
319
320	return status;
321}
322
323
324/* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
325 * which only exposes a polled programming interface; and since
326 * these calls map directly to those EFI requests; we don't demand
327 * we have an IRQ for this chip when we go through this API.
328 *
329 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
330 * though, managed through RTC_AIE_{ON,OFF} requests.
331 */
332
333static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
334{
335	struct i2c_client	*client = to_i2c_client(dev);
336	struct rs5c372		*rs5c = i2c_get_clientdata(client);
337	int			status;
338
339	status = rs5c_get_regs(rs5c);
340	if (status < 0)
341		return status;
342
343	/* report alarm time */
344	t->time.tm_sec = 0;
345	t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
346	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
347	t->time.tm_mday = -1;
348	t->time.tm_mon = -1;
349	t->time.tm_year = -1;
350	t->time.tm_wday = -1;
351	t->time.tm_yday = -1;
352	t->time.tm_isdst = -1;
353
354	/* ... and status */
355	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
356	t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
357
358	return 0;
359}
360
361static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
362{
363	struct i2c_client	*client = to_i2c_client(dev);
364	struct rs5c372		*rs5c = i2c_get_clientdata(client);
365	int			status, addr, i;
366	unsigned char		buf[3];
367
368	/* only handle up to 24 hours in the future, like RTC_ALM_SET */
369	if (t->time.tm_mday != -1
370			|| t->time.tm_mon != -1
371			|| t->time.tm_year != -1)
372		return -EINVAL;
373
374	/* REVISIT: round up tm_sec */
375
376	/* if needed, disable irq (clears pending status) */
377	status = rs5c_get_regs(rs5c);
378	if (status < 0)
379		return status;
380	if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
381		addr = RS5C_ADDR(RS5C_REG_CTRL1);
382		buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
383		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
384			dev_dbg(dev, "can't disable alarm\n");
385			return -EIO;
386		}
387		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
388	}
389
390	/* set alarm */
391	buf[0] = bin2bcd(t->time.tm_min);
392	buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
393	buf[2] = 0x7f;	/* any/all days */
394
395	for (i = 0; i < sizeof(buf); i++) {
396		addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
397		if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
398			dev_dbg(dev, "can't set alarm time\n");
399			return -EIO;
400		}
401	}
402
403	/* ... and maybe enable its irq */
404	if (t->enabled) {
405		addr = RS5C_ADDR(RS5C_REG_CTRL1);
406		buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
407		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
408			dev_warn(dev, "can't enable alarm\n");
409		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
410	}
411
412	return 0;
413}
414
415#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
416
417static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
418{
419	int err, osc, trim;
420
421	err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
422	if (err == 0) {
423		seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
424				osc / 1000, osc % 1000);
425		seq_printf(seq, "trim\t\t: %d\n", trim);
426	}
427
428	return 0;
429}
430
431#else
432#define	rs5c372_rtc_proc	NULL
433#endif
434
435static const struct rtc_class_ops rs5c372_rtc_ops = {
436	.proc		= rs5c372_rtc_proc,
437	.read_time	= rs5c372_rtc_read_time,
438	.set_time	= rs5c372_rtc_set_time,
439	.read_alarm	= rs5c_read_alarm,
440	.set_alarm	= rs5c_set_alarm,
441	.alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
442};
443
444#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
445
446static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
447				struct device_attribute *attr, char *buf)
448{
449	int err, trim;
450
451	err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
452	if (err)
453		return err;
454
455	return sprintf(buf, "%d\n", trim);
456}
457static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
458
459static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
460				struct device_attribute *attr, char *buf)
461{
462	int err, osc;
463
464	err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
465	if (err)
466		return err;
467
468	return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
469}
470static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
471
472static int rs5c_sysfs_register(struct device *dev)
473{
474	int err;
475
476	err = device_create_file(dev, &dev_attr_trim);
477	if (err)
478		return err;
479	err = device_create_file(dev, &dev_attr_osc);
480	if (err)
481		device_remove_file(dev, &dev_attr_trim);
482
483	return err;
484}
485
486static void rs5c_sysfs_unregister(struct device *dev)
487{
488	device_remove_file(dev, &dev_attr_trim);
489	device_remove_file(dev, &dev_attr_osc);
490}
491
492#else
493static int rs5c_sysfs_register(struct device *dev)
494{
495	return 0;
496}
497
498static void rs5c_sysfs_unregister(struct device *dev)
499{
500	/* nothing */
501}
502#endif	/* SYSFS */
503
504static struct i2c_driver rs5c372_driver;
505
506static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
507{
508	unsigned char buf[2];
509	int addr, i, ret = 0;
510
511	if (rs5c372->type == rtc_r2025sd) {
512		if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
513			return ret;
514		rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
515	} else {
516		if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
517			return ret;
518		rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
519	}
520
521	addr   = RS5C_ADDR(RS5C_REG_CTRL1);
522	buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
523	buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
524
525	/* use 24hr mode */
526	switch (rs5c372->type) {
527	case rtc_rs5c372a:
528	case rtc_rs5c372b:
529		buf[1] |= RS5C372_CTRL2_24;
530		rs5c372->time24 = 1;
531		break;
532	case rtc_r2025sd:
533	case rtc_r2221tl:
534	case rtc_rv5c386:
535	case rtc_rv5c387a:
536		buf[0] |= RV5C387_CTRL1_24;
537		rs5c372->time24 = 1;
538		break;
539	default:
540		/* impossible */
541		break;
542	}
543
544	for (i = 0; i < sizeof(buf); i++) {
545		addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
546		ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
547		if (unlikely(ret < 0))
548			return ret;
549	}
550
551	rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
552	rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
553
554	return 0;
555}
556
557static int rs5c372_probe(struct i2c_client *client,
558			 const struct i2c_device_id *id)
559{
560	int err = 0;
561	int smbus_mode = 0;
562	struct rs5c372 *rs5c372;
563	struct rtc_time tm;
564
565	dev_dbg(&client->dev, "%s\n", __func__);
566
567	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
568			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
569		/*
570		 * If we don't have any master mode adapter, try breaking
571		 * it down in to the barest of capabilities.
572		 */
573		if (i2c_check_functionality(client->adapter,
574				I2C_FUNC_SMBUS_BYTE_DATA |
575				I2C_FUNC_SMBUS_I2C_BLOCK))
576			smbus_mode = 1;
577		else {
578			/* Still no good, give up */
579			err = -ENODEV;
580			goto exit;
581		}
582	}
583
584	rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
585				GFP_KERNEL);
586	if (!rs5c372) {
587		err = -ENOMEM;
588		goto exit;
589	}
590
591	rs5c372->client = client;
592	i2c_set_clientdata(client, rs5c372);
593	rs5c372->type = id->driver_data;
594
595	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
596	rs5c372->regs = &rs5c372->buf[1];
597	rs5c372->smbus = smbus_mode;
598
599	err = rs5c_get_regs(rs5c372);
600	if (err < 0)
601		goto exit;
602
603	/* clock may be set for am/pm or 24 hr time */
604	switch (rs5c372->type) {
605	case rtc_rs5c372a:
606	case rtc_rs5c372b:
607		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
608		 * so does periodic irq, except some 327a modes.
609		 */
610		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
611			rs5c372->time24 = 1;
612		break;
613	case rtc_r2025sd:
614	case rtc_r2221tl:
615	case rtc_rv5c386:
616	case rtc_rv5c387a:
617		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
618			rs5c372->time24 = 1;
619		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
620		 * irq, on both 386 and 387
621		 */
622		break;
623	default:
624		dev_err(&client->dev, "unknown RTC type\n");
625		goto exit;
626	}
627
628	/* if the oscillator lost power and no other software (like
629	 * the bootloader) set it up, do it here.
630	 *
631	 * The R2025S/D does this a little differently than the other
632	 * parts, so we special case that..
633	 */
634	err = rs5c_oscillator_setup(rs5c372);
635	if (unlikely(err < 0)) {
636		dev_err(&client->dev, "setup error\n");
637		goto exit;
638	}
639
640	if (rs5c372_get_datetime(client, &tm) < 0)
641		dev_warn(&client->dev, "clock needs to be set\n");
642
643	dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
644			({ char *s; switch (rs5c372->type) {
645			case rtc_r2025sd:	s = "r2025sd"; break;
646			case rtc_r2221tl:	s = "r2221tl"; break;
647			case rtc_rs5c372a:	s = "rs5c372a"; break;
648			case rtc_rs5c372b:	s = "rs5c372b"; break;
649			case rtc_rv5c386:	s = "rv5c386"; break;
650			case rtc_rv5c387a:	s = "rv5c387a"; break;
651			default:		s = "chip"; break;
652			}; s;}),
653			rs5c372->time24 ? "24hr" : "am/pm"
654			);
655
656	/* REVISIT use client->irq to register alarm irq ... */
657	rs5c372->rtc = devm_rtc_device_register(&client->dev,
658					rs5c372_driver.driver.name,
659					&rs5c372_rtc_ops, THIS_MODULE);
660
661	if (IS_ERR(rs5c372->rtc)) {
662		err = PTR_ERR(rs5c372->rtc);
663		goto exit;
664	}
665
666	err = rs5c_sysfs_register(&client->dev);
667	if (err)
668		goto exit;
669
670	return 0;
671
672exit:
673	return err;
674}
675
676static int rs5c372_remove(struct i2c_client *client)
677{
678	rs5c_sysfs_unregister(&client->dev);
679	return 0;
680}
681
682static struct i2c_driver rs5c372_driver = {
683	.driver		= {
684		.name	= "rtc-rs5c372",
685	},
686	.probe		= rs5c372_probe,
687	.remove		= rs5c372_remove,
688	.id_table	= rs5c372_id,
689};
690
691module_i2c_driver(rs5c372_driver);
692
693MODULE_AUTHOR(
694		"Pavel Mironchik <pmironchik@optifacio.net>, "
695		"Alessandro Zummo <a.zummo@towertech.it>, "
696		"Paul Mundt <lethal@linux-sh.org>");
697MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
698MODULE_LICENSE("GPL");
699MODULE_VERSION(DRV_VERSION);
v3.15
  1/*
  2 * An I2C driver for Ricoh RS5C372, R2025S/D and RV5C38[67] RTCs
  3 *
  4 * Copyright (C) 2005 Pavel Mironchik <pmironchik@optifacio.net>
  5 * Copyright (C) 2006 Tower Technologies
  6 * Copyright (C) 2008 Paul Mundt
  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/i2c.h>
 14#include <linux/rtc.h>
 15#include <linux/bcd.h>
 16#include <linux/slab.h>
 17#include <linux/module.h>
 18
 19#define DRV_VERSION "0.6"
 20
 21
 22/*
 23 * Ricoh has a family of I2C based RTCs, which differ only slightly from
 24 * each other.  Differences center on pinout (e.g. how many interrupts,
 25 * output clock, etc) and how the control registers are used.  The '372
 26 * is significant only because that's the one this driver first supported.
 27 */
 28#define RS5C372_REG_SECS	0
 29#define RS5C372_REG_MINS	1
 30#define RS5C372_REG_HOURS	2
 31#define RS5C372_REG_WDAY	3
 32#define RS5C372_REG_DAY		4
 33#define RS5C372_REG_MONTH	5
 34#define RS5C372_REG_YEAR	6
 35#define RS5C372_REG_TRIM	7
 36#	define RS5C372_TRIM_XSL		0x80
 37#	define RS5C372_TRIM_MASK	0x7F
 38
 39#define RS5C_REG_ALARM_A_MIN	8			/* or ALARM_W */
 40#define RS5C_REG_ALARM_A_HOURS	9
 41#define RS5C_REG_ALARM_A_WDAY	10
 42
 43#define RS5C_REG_ALARM_B_MIN	11			/* or ALARM_D */
 44#define RS5C_REG_ALARM_B_HOURS	12
 45#define RS5C_REG_ALARM_B_WDAY	13			/* (ALARM_B only) */
 46
 47#define RS5C_REG_CTRL1		14
 48#	define RS5C_CTRL1_AALE		(1 << 7)	/* or WALE */
 49#	define RS5C_CTRL1_BALE		(1 << 6)	/* or DALE */
 50#	define RV5C387_CTRL1_24		(1 << 5)
 51#	define RS5C372A_CTRL1_SL1	(1 << 5)
 52#	define RS5C_CTRL1_CT_MASK	(7 << 0)
 53#	define RS5C_CTRL1_CT0		(0 << 0)	/* no periodic irq */
 54#	define RS5C_CTRL1_CT4		(4 << 0)	/* 1 Hz level irq */
 55#define RS5C_REG_CTRL2		15
 56#	define RS5C372_CTRL2_24		(1 << 5)
 57#	define R2025_CTRL2_XST		(1 << 5)
 58#	define RS5C_CTRL2_XSTP		(1 << 4)	/* only if !R2025S/D */
 59#	define RS5C_CTRL2_CTFG		(1 << 2)
 60#	define RS5C_CTRL2_AAFG		(1 << 1)	/* or WAFG */
 61#	define RS5C_CTRL2_BAFG		(1 << 0)	/* or DAFG */
 62
 63
 64/* to read (style 1) or write registers starting at R */
 65#define RS5C_ADDR(R)		(((R) << 4) | 0)
 66
 67
 68enum rtc_type {
 69	rtc_undef = 0,
 70	rtc_r2025sd,
 71	rtc_r2221tl,
 72	rtc_rs5c372a,
 73	rtc_rs5c372b,
 74	rtc_rv5c386,
 75	rtc_rv5c387a,
 76};
 77
 78static const struct i2c_device_id rs5c372_id[] = {
 79	{ "r2025sd", rtc_r2025sd },
 80	{ "r2221tl", rtc_r2221tl },
 81	{ "rs5c372a", rtc_rs5c372a },
 82	{ "rs5c372b", rtc_rs5c372b },
 83	{ "rv5c386", rtc_rv5c386 },
 84	{ "rv5c387a", rtc_rv5c387a },
 85	{ }
 86};
 87MODULE_DEVICE_TABLE(i2c, rs5c372_id);
 88
 89/* REVISIT:  this assumes that:
 90 *  - we're in the 21st century, so it's safe to ignore the century
 91 *    bit for rv5c38[67] (REG_MONTH bit 7);
 92 *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
 93 */
 94struct rs5c372 {
 95	struct i2c_client	*client;
 96	struct rtc_device	*rtc;
 97	enum rtc_type		type;
 98	unsigned		time24:1;
 99	unsigned		has_irq:1;
100	unsigned		smbus:1;
101	char			buf[17];
102	char			*regs;
103};
104
105static int rs5c_get_regs(struct rs5c372 *rs5c)
106{
107	struct i2c_client	*client = rs5c->client;
108	struct i2c_msg		msgs[] = {
109		{
110			.addr = client->addr,
111			.flags = I2C_M_RD,
112			.len = sizeof(rs5c->buf),
113			.buf = rs5c->buf
114		},
115	};
116
117	/* This implements the third reading method from the datasheet, using
118	 * an internal address that's reset after each transaction (by STOP)
119	 * to 0x0f ... so we read extra registers, and skip the first one.
120	 *
121	 * The first method doesn't work with the iop3xx adapter driver, on at
122	 * least 80219 chips; this works around that bug.
123	 *
124	 * The third method on the other hand doesn't work for the SMBus-only
125	 * configurations, so we use the the first method there, stripping off
126	 * the extra register in the process.
127	 */
128	if (rs5c->smbus) {
129		int addr = RS5C_ADDR(RS5C372_REG_SECS);
130		int size = sizeof(rs5c->buf) - 1;
131
132		if (i2c_smbus_read_i2c_block_data(client, addr, size,
133						  rs5c->buf + 1) != size) {
134			dev_warn(&client->dev, "can't read registers\n");
135			return -EIO;
136		}
137	} else {
138		if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
139			dev_warn(&client->dev, "can't read registers\n");
140			return -EIO;
141		}
142	}
143
144	dev_dbg(&client->dev,
145		"%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
146		"%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
147		rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
148		rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
149		rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
150		rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
151
152	return 0;
153}
154
155static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
156{
157	unsigned	hour;
158
159	if (rs5c->time24)
160		return bcd2bin(reg & 0x3f);
161
162	hour = bcd2bin(reg & 0x1f);
163	if (hour == 12)
164		hour = 0;
165	if (reg & 0x20)
166		hour += 12;
167	return hour;
168}
169
170static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
171{
172	if (rs5c->time24)
173		return bin2bcd(hour);
174
175	if (hour > 12)
176		return 0x20 | bin2bcd(hour - 12);
177	if (hour == 12)
178		return 0x20 | bin2bcd(12);
179	if (hour == 0)
180		return bin2bcd(12);
181	return bin2bcd(hour);
182}
183
184static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
185{
186	struct rs5c372	*rs5c = i2c_get_clientdata(client);
187	int		status = rs5c_get_regs(rs5c);
188
189	if (status < 0)
190		return status;
191
192	tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
193	tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
194	tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
195
196	tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
197	tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
198
199	/* tm->tm_mon is zero-based */
200	tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
201
202	/* year is 1900 + tm->tm_year */
203	tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
204
205	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
206		"mday=%d, mon=%d, year=%d, wday=%d\n",
207		__func__,
208		tm->tm_sec, tm->tm_min, tm->tm_hour,
209		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
210
211	/* rtc might need initialization */
212	return rtc_valid_tm(tm);
213}
214
215static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
216{
217	struct rs5c372	*rs5c = i2c_get_clientdata(client);
218	unsigned char	buf[7];
219	int		addr;
220
221	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
222		"mday=%d, mon=%d, year=%d, wday=%d\n",
223		__func__,
224		tm->tm_sec, tm->tm_min, tm->tm_hour,
225		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
226
227	addr   = RS5C_ADDR(RS5C372_REG_SECS);
228	buf[0] = bin2bcd(tm->tm_sec);
229	buf[1] = bin2bcd(tm->tm_min);
230	buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
231	buf[3] = bin2bcd(tm->tm_wday);
232	buf[4] = bin2bcd(tm->tm_mday);
233	buf[5] = bin2bcd(tm->tm_mon + 1);
234	buf[6] = bin2bcd(tm->tm_year - 100);
235
236	if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
237		dev_err(&client->dev, "%s: write error\n", __func__);
238		return -EIO;
239	}
240
241	return 0;
242}
243
244#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
245#define	NEED_TRIM
246#endif
247
248#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
249#define	NEED_TRIM
250#endif
251
252#ifdef	NEED_TRIM
253static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
254{
255	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
256	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
257
258	if (osc)
259		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
260
261	if (trim) {
262		dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
263		tmp &= RS5C372_TRIM_MASK;
264		if (tmp & 0x3e) {
265			int t = tmp & 0x3f;
266
267			if (tmp & 0x40)
268				t = (~t | (s8)0xc0) + 1;
269			else
270				t = t - 1;
271
272			tmp = t * 2;
273		} else
274			tmp = 0;
275		*trim = tmp;
276	}
277
278	return 0;
279}
280#endif
281
282static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
283{
284	return rs5c372_get_datetime(to_i2c_client(dev), tm);
285}
286
287static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
288{
289	return rs5c372_set_datetime(to_i2c_client(dev), tm);
290}
291
292
293static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
294{
295	struct i2c_client	*client = to_i2c_client(dev);
296	struct rs5c372		*rs5c = i2c_get_clientdata(client);
297	unsigned char		buf;
298	int			status, addr;
299
300	buf = rs5c->regs[RS5C_REG_CTRL1];
301
302	if (!rs5c->has_irq)
303		return -EINVAL;
304
305	status = rs5c_get_regs(rs5c);
306	if (status < 0)
307		return status;
308
309	addr = RS5C_ADDR(RS5C_REG_CTRL1);
310	if (enabled)
311		buf |= RS5C_CTRL1_AALE;
312	else
313		buf &= ~RS5C_CTRL1_AALE;
314
315	if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
316		dev_warn(dev, "can't update alarm\n");
317		status = -EIO;
318	} else
319		rs5c->regs[RS5C_REG_CTRL1] = buf;
320
321	return status;
322}
323
324
325/* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
326 * which only exposes a polled programming interface; and since
327 * these calls map directly to those EFI requests; we don't demand
328 * we have an IRQ for this chip when we go through this API.
329 *
330 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
331 * though, managed through RTC_AIE_{ON,OFF} requests.
332 */
333
334static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
335{
336	struct i2c_client	*client = to_i2c_client(dev);
337	struct rs5c372		*rs5c = i2c_get_clientdata(client);
338	int			status;
339
340	status = rs5c_get_regs(rs5c);
341	if (status < 0)
342		return status;
343
344	/* report alarm time */
345	t->time.tm_sec = 0;
346	t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
347	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
348	t->time.tm_mday = -1;
349	t->time.tm_mon = -1;
350	t->time.tm_year = -1;
351	t->time.tm_wday = -1;
352	t->time.tm_yday = -1;
353	t->time.tm_isdst = -1;
354
355	/* ... and status */
356	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
357	t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
358
359	return 0;
360}
361
362static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
363{
364	struct i2c_client	*client = to_i2c_client(dev);
365	struct rs5c372		*rs5c = i2c_get_clientdata(client);
366	int			status, addr, i;
367	unsigned char		buf[3];
368
369	/* only handle up to 24 hours in the future, like RTC_ALM_SET */
370	if (t->time.tm_mday != -1
371			|| t->time.tm_mon != -1
372			|| t->time.tm_year != -1)
373		return -EINVAL;
374
375	/* REVISIT: round up tm_sec */
376
377	/* if needed, disable irq (clears pending status) */
378	status = rs5c_get_regs(rs5c);
379	if (status < 0)
380		return status;
381	if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
382		addr = RS5C_ADDR(RS5C_REG_CTRL1);
383		buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
384		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
385			dev_dbg(dev, "can't disable alarm\n");
386			return -EIO;
387		}
388		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
389	}
390
391	/* set alarm */
392	buf[0] = bin2bcd(t->time.tm_min);
393	buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
394	buf[2] = 0x7f;	/* any/all days */
395
396	for (i = 0; i < sizeof(buf); i++) {
397		addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
398		if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
399			dev_dbg(dev, "can't set alarm time\n");
400			return -EIO;
401		}
402	}
403
404	/* ... and maybe enable its irq */
405	if (t->enabled) {
406		addr = RS5C_ADDR(RS5C_REG_CTRL1);
407		buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
408		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
409			dev_warn(dev, "can't enable alarm\n");
410		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
411	}
412
413	return 0;
414}
415
416#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
417
418static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
419{
420	int err, osc, trim;
421
422	err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
423	if (err == 0) {
424		seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
425				osc / 1000, osc % 1000);
426		seq_printf(seq, "trim\t\t: %d\n", trim);
427	}
428
429	return 0;
430}
431
432#else
433#define	rs5c372_rtc_proc	NULL
434#endif
435
436static const struct rtc_class_ops rs5c372_rtc_ops = {
437	.proc		= rs5c372_rtc_proc,
438	.read_time	= rs5c372_rtc_read_time,
439	.set_time	= rs5c372_rtc_set_time,
440	.read_alarm	= rs5c_read_alarm,
441	.set_alarm	= rs5c_set_alarm,
442	.alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
443};
444
445#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
446
447static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
448				struct device_attribute *attr, char *buf)
449{
450	int err, trim;
451
452	err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
453	if (err)
454		return err;
455
456	return sprintf(buf, "%d\n", trim);
457}
458static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
459
460static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
461				struct device_attribute *attr, char *buf)
462{
463	int err, osc;
464
465	err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
466	if (err)
467		return err;
468
469	return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
470}
471static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
472
473static int rs5c_sysfs_register(struct device *dev)
474{
475	int err;
476
477	err = device_create_file(dev, &dev_attr_trim);
478	if (err)
479		return err;
480	err = device_create_file(dev, &dev_attr_osc);
481	if (err)
482		device_remove_file(dev, &dev_attr_trim);
483
484	return err;
485}
486
487static void rs5c_sysfs_unregister(struct device *dev)
488{
489	device_remove_file(dev, &dev_attr_trim);
490	device_remove_file(dev, &dev_attr_osc);
491}
492
493#else
494static int rs5c_sysfs_register(struct device *dev)
495{
496	return 0;
497}
498
499static void rs5c_sysfs_unregister(struct device *dev)
500{
501	/* nothing */
502}
503#endif	/* SYSFS */
504
505static struct i2c_driver rs5c372_driver;
506
507static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
508{
509	unsigned char buf[2];
510	int addr, i, ret = 0;
511
512	if (rs5c372->type == rtc_r2025sd) {
513		if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
514			return ret;
515		rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
516	} else {
517		if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
518			return ret;
519		rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
520	}
521
522	addr   = RS5C_ADDR(RS5C_REG_CTRL1);
523	buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
524	buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
525
526	/* use 24hr mode */
527	switch (rs5c372->type) {
528	case rtc_rs5c372a:
529	case rtc_rs5c372b:
530		buf[1] |= RS5C372_CTRL2_24;
531		rs5c372->time24 = 1;
532		break;
533	case rtc_r2025sd:
534	case rtc_r2221tl:
535	case rtc_rv5c386:
536	case rtc_rv5c387a:
537		buf[0] |= RV5C387_CTRL1_24;
538		rs5c372->time24 = 1;
539		break;
540	default:
541		/* impossible */
542		break;
543	}
544
545	for (i = 0; i < sizeof(buf); i++) {
546		addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
547		ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
548		if (unlikely(ret < 0))
549			return ret;
550	}
551
552	rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
553	rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
554
555	return 0;
556}
557
558static int rs5c372_probe(struct i2c_client *client,
559			 const struct i2c_device_id *id)
560{
561	int err = 0;
562	int smbus_mode = 0;
563	struct rs5c372 *rs5c372;
564	struct rtc_time tm;
565
566	dev_dbg(&client->dev, "%s\n", __func__);
567
568	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
569			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
570		/*
571		 * If we don't have any master mode adapter, try breaking
572		 * it down in to the barest of capabilities.
573		 */
574		if (i2c_check_functionality(client->adapter,
575				I2C_FUNC_SMBUS_BYTE_DATA |
576				I2C_FUNC_SMBUS_I2C_BLOCK))
577			smbus_mode = 1;
578		else {
579			/* Still no good, give up */
580			err = -ENODEV;
581			goto exit;
582		}
583	}
584
585	rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
586				GFP_KERNEL);
587	if (!rs5c372) {
588		err = -ENOMEM;
589		goto exit;
590	}
591
592	rs5c372->client = client;
593	i2c_set_clientdata(client, rs5c372);
594	rs5c372->type = id->driver_data;
595
596	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
597	rs5c372->regs = &rs5c372->buf[1];
598	rs5c372->smbus = smbus_mode;
599
600	err = rs5c_get_regs(rs5c372);
601	if (err < 0)
602		goto exit;
603
604	/* clock may be set for am/pm or 24 hr time */
605	switch (rs5c372->type) {
606	case rtc_rs5c372a:
607	case rtc_rs5c372b:
608		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
609		 * so does periodic irq, except some 327a modes.
610		 */
611		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
612			rs5c372->time24 = 1;
613		break;
614	case rtc_r2025sd:
615	case rtc_r2221tl:
616	case rtc_rv5c386:
617	case rtc_rv5c387a:
618		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
619			rs5c372->time24 = 1;
620		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
621		 * irq, on both 386 and 387
622		 */
623		break;
624	default:
625		dev_err(&client->dev, "unknown RTC type\n");
626		goto exit;
627	}
628
629	/* if the oscillator lost power and no other software (like
630	 * the bootloader) set it up, do it here.
631	 *
632	 * The R2025S/D does this a little differently than the other
633	 * parts, so we special case that..
634	 */
635	err = rs5c_oscillator_setup(rs5c372);
636	if (unlikely(err < 0)) {
637		dev_err(&client->dev, "setup error\n");
638		goto exit;
639	}
640
641	if (rs5c372_get_datetime(client, &tm) < 0)
642		dev_warn(&client->dev, "clock needs to be set\n");
643
644	dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
645			({ char *s; switch (rs5c372->type) {
646			case rtc_r2025sd:	s = "r2025sd"; break;
647			case rtc_r2221tl:	s = "r2221tl"; break;
648			case rtc_rs5c372a:	s = "rs5c372a"; break;
649			case rtc_rs5c372b:	s = "rs5c372b"; break;
650			case rtc_rv5c386:	s = "rv5c386"; break;
651			case rtc_rv5c387a:	s = "rv5c387a"; break;
652			default:		s = "chip"; break;
653			}; s;}),
654			rs5c372->time24 ? "24hr" : "am/pm"
655			);
656
657	/* REVISIT use client->irq to register alarm irq ... */
658	rs5c372->rtc = devm_rtc_device_register(&client->dev,
659					rs5c372_driver.driver.name,
660					&rs5c372_rtc_ops, THIS_MODULE);
661
662	if (IS_ERR(rs5c372->rtc)) {
663		err = PTR_ERR(rs5c372->rtc);
664		goto exit;
665	}
666
667	err = rs5c_sysfs_register(&client->dev);
668	if (err)
669		goto exit;
670
671	return 0;
672
673exit:
674	return err;
675}
676
677static int rs5c372_remove(struct i2c_client *client)
678{
679	rs5c_sysfs_unregister(&client->dev);
680	return 0;
681}
682
683static struct i2c_driver rs5c372_driver = {
684	.driver		= {
685		.name	= "rtc-rs5c372",
686	},
687	.probe		= rs5c372_probe,
688	.remove		= rs5c372_remove,
689	.id_table	= rs5c372_id,
690};
691
692module_i2c_driver(rs5c372_driver);
693
694MODULE_AUTHOR(
695		"Pavel Mironchik <pmironchik@optifacio.net>, "
696		"Alessandro Zummo <a.zummo@towertech.it>, "
697		"Paul Mundt <lethal@linux-sh.org>");
698MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
699MODULE_LICENSE("GPL");
700MODULE_VERSION(DRV_VERSION);