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v4.17
  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#include <linux/of_device.h>
 
 19
 20/*
 21 * Ricoh has a family of I2C based RTCs, which differ only slightly from
 22 * each other.  Differences center on pinout (e.g. how many interrupts,
 23 * output clock, etc) and how the control registers are used.  The '372
 24 * is significant only because that's the one this driver first supported.
 25 */
 26#define RS5C372_REG_SECS	0
 27#define RS5C372_REG_MINS	1
 28#define RS5C372_REG_HOURS	2
 29#define RS5C372_REG_WDAY	3
 30#define RS5C372_REG_DAY		4
 31#define RS5C372_REG_MONTH	5
 32#define RS5C372_REG_YEAR	6
 33#define RS5C372_REG_TRIM	7
 34#	define RS5C372_TRIM_XSL		0x80
 35#	define RS5C372_TRIM_MASK	0x7F
 36
 37#define RS5C_REG_ALARM_A_MIN	8			/* or ALARM_W */
 38#define RS5C_REG_ALARM_A_HOURS	9
 39#define RS5C_REG_ALARM_A_WDAY	10
 40
 41#define RS5C_REG_ALARM_B_MIN	11			/* or ALARM_D */
 42#define RS5C_REG_ALARM_B_HOURS	12
 43#define RS5C_REG_ALARM_B_WDAY	13			/* (ALARM_B only) */
 44
 45#define RS5C_REG_CTRL1		14
 46#	define RS5C_CTRL1_AALE		(1 << 7)	/* or WALE */
 47#	define RS5C_CTRL1_BALE		(1 << 6)	/* or DALE */
 48#	define RV5C387_CTRL1_24		(1 << 5)
 49#	define RS5C372A_CTRL1_SL1	(1 << 5)
 50#	define RS5C_CTRL1_CT_MASK	(7 << 0)
 51#	define RS5C_CTRL1_CT0		(0 << 0)	/* no periodic irq */
 52#	define RS5C_CTRL1_CT4		(4 << 0)	/* 1 Hz level irq */
 53#define RS5C_REG_CTRL2		15
 54#	define RS5C372_CTRL2_24		(1 << 5)
 55#	define R2025_CTRL2_XST		(1 << 5)
 56#	define RS5C_CTRL2_XSTP		(1 << 4)	/* only if !R2025S/D */
 57#	define RS5C_CTRL2_CTFG		(1 << 2)
 58#	define RS5C_CTRL2_AAFG		(1 << 1)	/* or WAFG */
 59#	define RS5C_CTRL2_BAFG		(1 << 0)	/* or DAFG */
 60
 61
 62/* to read (style 1) or write registers starting at R */
 63#define RS5C_ADDR(R)		(((R) << 4) | 0)
 64
 65
 66enum rtc_type {
 67	rtc_undef = 0,
 68	rtc_r2025sd,
 69	rtc_r2221tl,
 70	rtc_rs5c372a,
 71	rtc_rs5c372b,
 72	rtc_rv5c386,
 73	rtc_rv5c387a,
 74};
 75
 76static const struct i2c_device_id rs5c372_id[] = {
 77	{ "r2025sd", rtc_r2025sd },
 78	{ "r2221tl", rtc_r2221tl },
 79	{ "rs5c372a", rtc_rs5c372a },
 80	{ "rs5c372b", rtc_rs5c372b },
 81	{ "rv5c386", rtc_rv5c386 },
 82	{ "rv5c387a", rtc_rv5c387a },
 83	{ }
 84};
 85MODULE_DEVICE_TABLE(i2c, rs5c372_id);
 86
 87static const struct of_device_id rs5c372_of_match[] = {
 88	{
 89		.compatible = "ricoh,r2025sd",
 90		.data = (void *)rtc_r2025sd
 91	},
 92	{
 93		.compatible = "ricoh,r2221tl",
 94		.data = (void *)rtc_r2221tl
 95	},
 96	{
 97		.compatible = "ricoh,rs5c372a",
 98		.data = (void *)rtc_rs5c372a
 99	},
100	{
101		.compatible = "ricoh,rs5c372b",
102		.data = (void *)rtc_rs5c372b
103	},
104	{
105		.compatible = "ricoh,rv5c386",
106		.data = (void *)rtc_rv5c386
107	},
108	{
109		.compatible = "ricoh,rv5c387a",
110		.data = (void *)rtc_rv5c387a
111	},
112	{ }
113};
114MODULE_DEVICE_TABLE(of, rs5c372_of_match);
115
116/* REVISIT:  this assumes that:
117 *  - we're in the 21st century, so it's safe to ignore the century
118 *    bit for rv5c38[67] (REG_MONTH bit 7);
119 *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
120 */
121struct rs5c372 {
122	struct i2c_client	*client;
123	struct rtc_device	*rtc;
124	enum rtc_type		type;
125	unsigned		time24:1;
126	unsigned		has_irq:1;
127	unsigned		smbus:1;
128	char			buf[17];
129	char			*regs;
130};
131
132static int rs5c_get_regs(struct rs5c372 *rs5c)
133{
134	struct i2c_client	*client = rs5c->client;
135	struct i2c_msg		msgs[] = {
136		{
137			.addr = client->addr,
138			.flags = I2C_M_RD,
139			.len = sizeof(rs5c->buf),
140			.buf = rs5c->buf
141		},
142	};
143
144	/* This implements the third reading method from the datasheet, using
145	 * an internal address that's reset after each transaction (by STOP)
146	 * to 0x0f ... so we read extra registers, and skip the first one.
147	 *
148	 * The first method doesn't work with the iop3xx adapter driver, on at
149	 * least 80219 chips; this works around that bug.
150	 *
151	 * The third method on the other hand doesn't work for the SMBus-only
152	 * configurations, so we use the the first method there, stripping off
153	 * the extra register in the process.
154	 */
155	if (rs5c->smbus) {
156		int addr = RS5C_ADDR(RS5C372_REG_SECS);
157		int size = sizeof(rs5c->buf) - 1;
158
159		if (i2c_smbus_read_i2c_block_data(client, addr, size,
160						  rs5c->buf + 1) != size) {
161			dev_warn(&client->dev, "can't read registers\n");
162			return -EIO;
163		}
164	} else {
165		if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
166			dev_warn(&client->dev, "can't read registers\n");
167			return -EIO;
168		}
169	}
170
171	dev_dbg(&client->dev,
172		"%3ph (%02x) %3ph (%02x), %3ph, %3ph; %02x %02x\n",
173		rs5c->regs + 0, rs5c->regs[3],
174		rs5c->regs + 4, rs5c->regs[7],
175		rs5c->regs + 8, rs5c->regs + 11,
176		rs5c->regs[14], rs5c->regs[15]);
 
177
178	return 0;
179}
180
181static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
182{
183	unsigned	hour;
184
185	if (rs5c->time24)
186		return bcd2bin(reg & 0x3f);
187
188	hour = bcd2bin(reg & 0x1f);
189	if (hour == 12)
190		hour = 0;
191	if (reg & 0x20)
192		hour += 12;
193	return hour;
194}
195
196static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
197{
198	if (rs5c->time24)
199		return bin2bcd(hour);
200
201	if (hour > 12)
202		return 0x20 | bin2bcd(hour - 12);
203	if (hour == 12)
204		return 0x20 | bin2bcd(12);
205	if (hour == 0)
206		return bin2bcd(12);
207	return bin2bcd(hour);
208}
209
210static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
211{
212	struct i2c_client *client = to_i2c_client(dev);
213	struct rs5c372	*rs5c = i2c_get_clientdata(client);
214	int		status = rs5c_get_regs(rs5c);
215
216	if (status < 0)
217		return status;
218
219	tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
220	tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
221	tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
222
223	tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
224	tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
225
226	/* tm->tm_mon is zero-based */
227	tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
228
229	/* year is 1900 + tm->tm_year */
230	tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
231
232	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
233		"mday=%d, mon=%d, year=%d, wday=%d\n",
234		__func__,
235		tm->tm_sec, tm->tm_min, tm->tm_hour,
236		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
237
238	return 0;
 
239}
240
241static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
242{
243	struct i2c_client *client = to_i2c_client(dev);
244	struct rs5c372	*rs5c = i2c_get_clientdata(client);
245	unsigned char	buf[7];
246	int		addr;
247
248	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
249		"mday=%d, mon=%d, year=%d, wday=%d\n",
250		__func__,
251		tm->tm_sec, tm->tm_min, tm->tm_hour,
252		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
253
254	addr   = RS5C_ADDR(RS5C372_REG_SECS);
255	buf[0] = bin2bcd(tm->tm_sec);
256	buf[1] = bin2bcd(tm->tm_min);
257	buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
258	buf[3] = bin2bcd(tm->tm_wday);
259	buf[4] = bin2bcd(tm->tm_mday);
260	buf[5] = bin2bcd(tm->tm_mon + 1);
261	buf[6] = bin2bcd(tm->tm_year - 100);
262
263	if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
264		dev_err(&client->dev, "%s: write error\n", __func__);
265		return -EIO;
266	}
267
268	return 0;
269}
270
271#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
272#define	NEED_TRIM
273#endif
274
275#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
276#define	NEED_TRIM
277#endif
278
279#ifdef	NEED_TRIM
280static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
281{
282	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
283	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
284
285	if (osc)
286		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
287
288	if (trim) {
289		dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
290		tmp &= RS5C372_TRIM_MASK;
291		if (tmp & 0x3e) {
292			int t = tmp & 0x3f;
293
294			if (tmp & 0x40)
295				t = (~t | (s8)0xc0) + 1;
296			else
297				t = t - 1;
298
299			tmp = t * 2;
300		} else
301			tmp = 0;
302		*trim = tmp;
303	}
304
305	return 0;
306}
307#endif
308
 
 
 
 
 
 
 
 
 
 
 
309static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
310{
311	struct i2c_client	*client = to_i2c_client(dev);
312	struct rs5c372		*rs5c = i2c_get_clientdata(client);
313	unsigned char		buf;
314	int			status, addr;
315
316	buf = rs5c->regs[RS5C_REG_CTRL1];
317
318	if (!rs5c->has_irq)
319		return -EINVAL;
320
321	status = rs5c_get_regs(rs5c);
322	if (status < 0)
323		return status;
324
325	addr = RS5C_ADDR(RS5C_REG_CTRL1);
326	if (enabled)
327		buf |= RS5C_CTRL1_AALE;
328	else
329		buf &= ~RS5C_CTRL1_AALE;
330
331	if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
332		dev_warn(dev, "can't update alarm\n");
 
333		status = -EIO;
334	} else
335		rs5c->regs[RS5C_REG_CTRL1] = buf;
336
337	return status;
338}
339
340
341/* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
342 * which only exposes a polled programming interface; and since
343 * these calls map directly to those EFI requests; we don't demand
344 * we have an IRQ for this chip when we go through this API.
345 *
346 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
347 * though, managed through RTC_AIE_{ON,OFF} requests.
348 */
349
350static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
351{
352	struct i2c_client	*client = to_i2c_client(dev);
353	struct rs5c372		*rs5c = i2c_get_clientdata(client);
354	int			status;
355
356	status = rs5c_get_regs(rs5c);
357	if (status < 0)
358		return status;
359
360	/* report alarm time */
361	t->time.tm_sec = 0;
362	t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
363	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
 
 
 
 
 
 
364
365	/* ... and status */
366	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
367	t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
368
369	return 0;
370}
371
372static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
373{
374	struct i2c_client	*client = to_i2c_client(dev);
375	struct rs5c372		*rs5c = i2c_get_clientdata(client);
376	int			status, addr, i;
377	unsigned char		buf[3];
378
379	/* only handle up to 24 hours in the future, like RTC_ALM_SET */
380	if (t->time.tm_mday != -1
381			|| t->time.tm_mon != -1
382			|| t->time.tm_year != -1)
383		return -EINVAL;
384
385	/* REVISIT: round up tm_sec */
386
387	/* if needed, disable irq (clears pending status) */
388	status = rs5c_get_regs(rs5c);
389	if (status < 0)
390		return status;
391	if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
392		addr = RS5C_ADDR(RS5C_REG_CTRL1);
393		buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
394		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
395			dev_dbg(dev, "can't disable alarm\n");
396			return -EIO;
397		}
398		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
399	}
400
401	/* set alarm */
402	buf[0] = bin2bcd(t->time.tm_min);
403	buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
404	buf[2] = 0x7f;	/* any/all days */
405
406	for (i = 0; i < sizeof(buf); i++) {
407		addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
408		if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
409			dev_dbg(dev, "can't set alarm time\n");
410			return -EIO;
411		}
412	}
413
414	/* ... and maybe enable its irq */
415	if (t->enabled) {
416		addr = RS5C_ADDR(RS5C_REG_CTRL1);
417		buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
418		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
419			dev_warn(dev, "can't enable alarm\n");
 
420		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
421	}
422
423	return 0;
424}
425
426#if IS_ENABLED(CONFIG_RTC_INTF_PROC)
427
428static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
429{
430	int err, osc, trim;
431
432	err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
433	if (err == 0) {
434		seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
435				osc / 1000, osc % 1000);
436		seq_printf(seq, "trim\t\t: %d\n", trim);
437	}
438
439	return 0;
440}
441
442#else
443#define	rs5c372_rtc_proc	NULL
444#endif
445
446static const struct rtc_class_ops rs5c372_rtc_ops = {
447	.proc		= rs5c372_rtc_proc,
448	.read_time	= rs5c372_rtc_read_time,
449	.set_time	= rs5c372_rtc_set_time,
450	.read_alarm	= rs5c_read_alarm,
451	.set_alarm	= rs5c_set_alarm,
452	.alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
453};
454
455#if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)
456
457static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
458				struct device_attribute *attr, char *buf)
459{
460	int err, trim;
461
462	err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
463	if (err)
464		return err;
465
466	return sprintf(buf, "%d\n", trim);
467}
468static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
469
470static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
471				struct device_attribute *attr, char *buf)
472{
473	int err, osc;
474
475	err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
476	if (err)
477		return err;
478
479	return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
480}
481static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
482
483static int rs5c_sysfs_register(struct device *dev)
484{
485	int err;
486
487	err = device_create_file(dev, &dev_attr_trim);
488	if (err)
489		return err;
490	err = device_create_file(dev, &dev_attr_osc);
491	if (err)
492		device_remove_file(dev, &dev_attr_trim);
493
494	return err;
495}
496
497static void rs5c_sysfs_unregister(struct device *dev)
498{
499	device_remove_file(dev, &dev_attr_trim);
500	device_remove_file(dev, &dev_attr_osc);
501}
502
503#else
504static int rs5c_sysfs_register(struct device *dev)
505{
506	return 0;
507}
508
509static void rs5c_sysfs_unregister(struct device *dev)
510{
511	/* nothing */
512}
513#endif	/* SYSFS */
514
515static struct i2c_driver rs5c372_driver;
516
517static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
518{
519	unsigned char buf[2];
520	int addr, i, ret = 0;
521
522	if (rs5c372->type == rtc_r2025sd) {
523		if (rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST)
524			return ret;
525		rs5c372->regs[RS5C_REG_CTRL2] |= R2025_CTRL2_XST;
526	} else {
527		if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
528			return ret;
529		rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
530	}
531
532	addr   = RS5C_ADDR(RS5C_REG_CTRL1);
533	buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
534	buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
535
536	/* use 24hr mode */
537	switch (rs5c372->type) {
538	case rtc_rs5c372a:
539	case rtc_rs5c372b:
540		buf[1] |= RS5C372_CTRL2_24;
541		rs5c372->time24 = 1;
542		break;
543	case rtc_r2025sd:
544	case rtc_r2221tl:
545	case rtc_rv5c386:
546	case rtc_rv5c387a:
547		buf[0] |= RV5C387_CTRL1_24;
548		rs5c372->time24 = 1;
549		break;
550	default:
551		/* impossible */
552		break;
553	}
554
555	for (i = 0; i < sizeof(buf); i++) {
556		addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
557		ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
558		if (unlikely(ret < 0))
559			return ret;
560	}
561
562	rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
563	rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
564
565	return 0;
566}
567
568static int rs5c372_probe(struct i2c_client *client,
569			 const struct i2c_device_id *id)
570{
571	int err = 0;
572	int smbus_mode = 0;
573	struct rs5c372 *rs5c372;
 
574
575	dev_dbg(&client->dev, "%s\n", __func__);
576
577	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
578			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
579		/*
580		 * If we don't have any master mode adapter, try breaking
581		 * it down in to the barest of capabilities.
582		 */
583		if (i2c_check_functionality(client->adapter,
584				I2C_FUNC_SMBUS_BYTE_DATA |
585				I2C_FUNC_SMBUS_I2C_BLOCK))
586			smbus_mode = 1;
587		else {
588			/* Still no good, give up */
589			err = -ENODEV;
590			goto exit;
591		}
592	}
593
594	rs5c372 = devm_kzalloc(&client->dev, sizeof(struct rs5c372),
595				GFP_KERNEL);
596	if (!rs5c372) {
597		err = -ENOMEM;
598		goto exit;
599	}
600
601	rs5c372->client = client;
602	i2c_set_clientdata(client, rs5c372);
603	if (client->dev.of_node)
604		rs5c372->type = (enum rtc_type)
605			of_device_get_match_data(&client->dev);
606	else
607		rs5c372->type = id->driver_data;
608
609	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
610	rs5c372->regs = &rs5c372->buf[1];
611	rs5c372->smbus = smbus_mode;
612
613	err = rs5c_get_regs(rs5c372);
614	if (err < 0)
615		goto exit;
616
617	/* clock may be set for am/pm or 24 hr time */
618	switch (rs5c372->type) {
619	case rtc_rs5c372a:
620	case rtc_rs5c372b:
621		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
622		 * so does periodic irq, except some 327a modes.
623		 */
624		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
625			rs5c372->time24 = 1;
626		break;
627	case rtc_r2025sd:
628	case rtc_r2221tl:
629	case rtc_rv5c386:
630	case rtc_rv5c387a:
631		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
632			rs5c372->time24 = 1;
633		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
634		 * irq, on both 386 and 387
635		 */
636		break;
637	default:
638		dev_err(&client->dev, "unknown RTC type\n");
639		goto exit;
640	}
641
642	/* if the oscillator lost power and no other software (like
643	 * the bootloader) set it up, do it here.
644	 *
645	 * The R2025S/D does this a little differently than the other
646	 * parts, so we special case that..
647	 */
648	err = rs5c_oscillator_setup(rs5c372);
649	if (unlikely(err < 0)) {
650		dev_err(&client->dev, "setup error\n");
651		goto exit;
652	}
653
654	dev_info(&client->dev, "%s found, %s\n",
 
 
 
655			({ char *s; switch (rs5c372->type) {
656			case rtc_r2025sd:	s = "r2025sd"; break;
657			case rtc_r2221tl:	s = "r2221tl"; break;
658			case rtc_rs5c372a:	s = "rs5c372a"; break;
659			case rtc_rs5c372b:	s = "rs5c372b"; break;
660			case rtc_rv5c386:	s = "rv5c386"; break;
661			case rtc_rv5c387a:	s = "rv5c387a"; break;
662			default:		s = "chip"; break;
663			}; s;}),
664			rs5c372->time24 ? "24hr" : "am/pm"
665			);
666
667	/* REVISIT use client->irq to register alarm irq ... */
668	rs5c372->rtc = devm_rtc_device_register(&client->dev,
669					rs5c372_driver.driver.name,
670					&rs5c372_rtc_ops, THIS_MODULE);
671
672	if (IS_ERR(rs5c372->rtc)) {
673		err = PTR_ERR(rs5c372->rtc);
674		goto exit;
675	}
676
677	err = rs5c_sysfs_register(&client->dev);
678	if (err)
679		goto exit;
680
681	return 0;
682
 
 
 
 
 
 
683exit:
684	return err;
685}
686
687static int rs5c372_remove(struct i2c_client *client)
688{
 
 
 
689	rs5c_sysfs_unregister(&client->dev);
 
690	return 0;
691}
692
693static struct i2c_driver rs5c372_driver = {
694	.driver		= {
695		.name	= "rtc-rs5c372",
696		.of_match_table = of_match_ptr(rs5c372_of_match),
697	},
698	.probe		= rs5c372_probe,
699	.remove		= rs5c372_remove,
700	.id_table	= rs5c372_id,
701};
702
703module_i2c_driver(rs5c372_driver);
 
 
 
 
 
 
 
 
 
 
 
704
705MODULE_AUTHOR(
706		"Pavel Mironchik <pmironchik@optifacio.net>, "
707		"Alessandro Zummo <a.zummo@towertech.it>, "
708		"Paul Mundt <lethal@linux-sh.org>");
709MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
710MODULE_LICENSE("GPL");
v3.1
  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
 18#define DRV_VERSION "0.6"
 19
 20
 21/*
 22 * Ricoh has a family of I2C based RTCs, which differ only slightly from
 23 * each other.  Differences center on pinout (e.g. how many interrupts,
 24 * output clock, etc) and how the control registers are used.  The '372
 25 * is significant only because that's the one this driver first supported.
 26 */
 27#define RS5C372_REG_SECS	0
 28#define RS5C372_REG_MINS	1
 29#define RS5C372_REG_HOURS	2
 30#define RS5C372_REG_WDAY	3
 31#define RS5C372_REG_DAY		4
 32#define RS5C372_REG_MONTH	5
 33#define RS5C372_REG_YEAR	6
 34#define RS5C372_REG_TRIM	7
 35#	define RS5C372_TRIM_XSL		0x80
 36#	define RS5C372_TRIM_MASK	0x7F
 37
 38#define RS5C_REG_ALARM_A_MIN	8			/* or ALARM_W */
 39#define RS5C_REG_ALARM_A_HOURS	9
 40#define RS5C_REG_ALARM_A_WDAY	10
 41
 42#define RS5C_REG_ALARM_B_MIN	11			/* or ALARM_D */
 43#define RS5C_REG_ALARM_B_HOURS	12
 44#define RS5C_REG_ALARM_B_WDAY	13			/* (ALARM_B only) */
 45
 46#define RS5C_REG_CTRL1		14
 47#	define RS5C_CTRL1_AALE		(1 << 7)	/* or WALE */
 48#	define RS5C_CTRL1_BALE		(1 << 6)	/* or DALE */
 49#	define RV5C387_CTRL1_24		(1 << 5)
 50#	define RS5C372A_CTRL1_SL1	(1 << 5)
 51#	define RS5C_CTRL1_CT_MASK	(7 << 0)
 52#	define RS5C_CTRL1_CT0		(0 << 0)	/* no periodic irq */
 53#	define RS5C_CTRL1_CT4		(4 << 0)	/* 1 Hz level irq */
 54#define RS5C_REG_CTRL2		15
 55#	define RS5C372_CTRL2_24		(1 << 5)
 56#	define R2025_CTRL2_XST		(1 << 5)
 57#	define RS5C_CTRL2_XSTP		(1 << 4)	/* only if !R2025S/D */
 58#	define RS5C_CTRL2_CTFG		(1 << 2)
 59#	define RS5C_CTRL2_AAFG		(1 << 1)	/* or WAFG */
 60#	define RS5C_CTRL2_BAFG		(1 << 0)	/* or DAFG */
 61
 62
 63/* to read (style 1) or write registers starting at R */
 64#define RS5C_ADDR(R)		(((R) << 4) | 0)
 65
 66
 67enum rtc_type {
 68	rtc_undef = 0,
 69	rtc_r2025sd,
 
 70	rtc_rs5c372a,
 71	rtc_rs5c372b,
 72	rtc_rv5c386,
 73	rtc_rv5c387a,
 74};
 75
 76static const struct i2c_device_id rs5c372_id[] = {
 77	{ "r2025sd", rtc_r2025sd },
 
 78	{ "rs5c372a", rtc_rs5c372a },
 79	{ "rs5c372b", rtc_rs5c372b },
 80	{ "rv5c386", rtc_rv5c386 },
 81	{ "rv5c387a", rtc_rv5c387a },
 82	{ }
 83};
 84MODULE_DEVICE_TABLE(i2c, rs5c372_id);
 85
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 86/* REVISIT:  this assumes that:
 87 *  - we're in the 21st century, so it's safe to ignore the century
 88 *    bit for rv5c38[67] (REG_MONTH bit 7);
 89 *  - we should use ALARM_A not ALARM_B (may be wrong on some boards)
 90 */
 91struct rs5c372 {
 92	struct i2c_client	*client;
 93	struct rtc_device	*rtc;
 94	enum rtc_type		type;
 95	unsigned		time24:1;
 96	unsigned		has_irq:1;
 97	unsigned		smbus:1;
 98	char			buf[17];
 99	char			*regs;
100};
101
102static int rs5c_get_regs(struct rs5c372 *rs5c)
103{
104	struct i2c_client	*client = rs5c->client;
105	struct i2c_msg		msgs[] = {
106		{ client->addr, I2C_M_RD, sizeof rs5c->buf, rs5c->buf },
 
 
 
 
 
107	};
108
109	/* This implements the third reading method from the datasheet, using
110	 * an internal address that's reset after each transaction (by STOP)
111	 * to 0x0f ... so we read extra registers, and skip the first one.
112	 *
113	 * The first method doesn't work with the iop3xx adapter driver, on at
114	 * least 80219 chips; this works around that bug.
115	 *
116	 * The third method on the other hand doesn't work for the SMBus-only
117	 * configurations, so we use the the first method there, stripping off
118	 * the extra register in the process.
119	 */
120	if (rs5c->smbus) {
121		int addr = RS5C_ADDR(RS5C372_REG_SECS);
122		int size = sizeof(rs5c->buf) - 1;
123
124		if (i2c_smbus_read_i2c_block_data(client, addr, size,
125						  rs5c->buf + 1) != size) {
126			dev_warn(&client->dev, "can't read registers\n");
127			return -EIO;
128		}
129	} else {
130		if ((i2c_transfer(client->adapter, msgs, 1)) != 1) {
131			dev_warn(&client->dev, "can't read registers\n");
132			return -EIO;
133		}
134	}
135
136	dev_dbg(&client->dev,
137		"%02x %02x %02x (%02x) %02x %02x %02x (%02x), "
138		"%02x %02x %02x, %02x %02x %02x; %02x %02x\n",
139		rs5c->regs[0],  rs5c->regs[1],  rs5c->regs[2],  rs5c->regs[3],
140		rs5c->regs[4],  rs5c->regs[5],  rs5c->regs[6],  rs5c->regs[7],
141		rs5c->regs[8],  rs5c->regs[9],  rs5c->regs[10], rs5c->regs[11],
142		rs5c->regs[12], rs5c->regs[13], rs5c->regs[14], rs5c->regs[15]);
143
144	return 0;
145}
146
147static unsigned rs5c_reg2hr(struct rs5c372 *rs5c, unsigned reg)
148{
149	unsigned	hour;
150
151	if (rs5c->time24)
152		return bcd2bin(reg & 0x3f);
153
154	hour = bcd2bin(reg & 0x1f);
155	if (hour == 12)
156		hour = 0;
157	if (reg & 0x20)
158		hour += 12;
159	return hour;
160}
161
162static unsigned rs5c_hr2reg(struct rs5c372 *rs5c, unsigned hour)
163{
164	if (rs5c->time24)
165		return bin2bcd(hour);
166
167	if (hour > 12)
168		return 0x20 | bin2bcd(hour - 12);
169	if (hour == 12)
170		return 0x20 | bin2bcd(12);
171	if (hour == 0)
172		return bin2bcd(12);
173	return bin2bcd(hour);
174}
175
176static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)
177{
 
178	struct rs5c372	*rs5c = i2c_get_clientdata(client);
179	int		status = rs5c_get_regs(rs5c);
180
181	if (status < 0)
182		return status;
183
184	tm->tm_sec = bcd2bin(rs5c->regs[RS5C372_REG_SECS] & 0x7f);
185	tm->tm_min = bcd2bin(rs5c->regs[RS5C372_REG_MINS] & 0x7f);
186	tm->tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C372_REG_HOURS]);
187
188	tm->tm_wday = bcd2bin(rs5c->regs[RS5C372_REG_WDAY] & 0x07);
189	tm->tm_mday = bcd2bin(rs5c->regs[RS5C372_REG_DAY] & 0x3f);
190
191	/* tm->tm_mon is zero-based */
192	tm->tm_mon = bcd2bin(rs5c->regs[RS5C372_REG_MONTH] & 0x1f) - 1;
193
194	/* year is 1900 + tm->tm_year */
195	tm->tm_year = bcd2bin(rs5c->regs[RS5C372_REG_YEAR]) + 100;
196
197	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
198		"mday=%d, mon=%d, year=%d, wday=%d\n",
199		__func__,
200		tm->tm_sec, tm->tm_min, tm->tm_hour,
201		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
202
203	/* rtc might need initialization */
204	return rtc_valid_tm(tm);
205}
206
207static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm)
208{
 
209	struct rs5c372	*rs5c = i2c_get_clientdata(client);
210	unsigned char	buf[7];
211	int		addr;
212
213	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d "
214		"mday=%d, mon=%d, year=%d, wday=%d\n",
215		__func__,
216		tm->tm_sec, tm->tm_min, tm->tm_hour,
217		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
218
219	addr   = RS5C_ADDR(RS5C372_REG_SECS);
220	buf[0] = bin2bcd(tm->tm_sec);
221	buf[1] = bin2bcd(tm->tm_min);
222	buf[2] = rs5c_hr2reg(rs5c, tm->tm_hour);
223	buf[3] = bin2bcd(tm->tm_wday);
224	buf[4] = bin2bcd(tm->tm_mday);
225	buf[5] = bin2bcd(tm->tm_mon + 1);
226	buf[6] = bin2bcd(tm->tm_year - 100);
227
228	if (i2c_smbus_write_i2c_block_data(client, addr, sizeof(buf), buf) < 0) {
229		dev_err(&client->dev, "%s: write error\n", __func__);
230		return -EIO;
231	}
232
233	return 0;
234}
235
236#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
237#define	NEED_TRIM
238#endif
239
240#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
241#define	NEED_TRIM
242#endif
243
244#ifdef	NEED_TRIM
245static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)
246{
247	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
248	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM];
249
250	if (osc)
251		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;
252
253	if (trim) {
254		dev_dbg(&client->dev, "%s: raw trim=%x\n", __func__, tmp);
255		tmp &= RS5C372_TRIM_MASK;
256		if (tmp & 0x3e) {
257			int t = tmp & 0x3f;
258
259			if (tmp & 0x40)
260				t = (~t | (s8)0xc0) + 1;
261			else
262				t = t - 1;
263
264			tmp = t * 2;
265		} else
266			tmp = 0;
267		*trim = tmp;
268	}
269
270	return 0;
271}
272#endif
273
274static int rs5c372_rtc_read_time(struct device *dev, struct rtc_time *tm)
275{
276	return rs5c372_get_datetime(to_i2c_client(dev), tm);
277}
278
279static int rs5c372_rtc_set_time(struct device *dev, struct rtc_time *tm)
280{
281	return rs5c372_set_datetime(to_i2c_client(dev), tm);
282}
283
284
285static int rs5c_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
286{
287	struct i2c_client	*client = to_i2c_client(dev);
288	struct rs5c372		*rs5c = i2c_get_clientdata(client);
289	unsigned char		buf;
290	int			status, addr;
291
292	buf = rs5c->regs[RS5C_REG_CTRL1];
293
294	if (!rs5c->has_irq)
295		return -EINVAL;
296
297	status = rs5c_get_regs(rs5c);
298	if (status < 0)
299		return status;
300
301	addr = RS5C_ADDR(RS5C_REG_CTRL1);
302	if (enabled)
303		buf |= RS5C_CTRL1_AALE;
304	else
305		buf &= ~RS5C_CTRL1_AALE;
306
307	if (i2c_smbus_write_byte_data(client, addr, buf) < 0) {
308		printk(KERN_WARNING "%s: can't update alarm\n",
309			rs5c->rtc->name);
310		status = -EIO;
311	} else
312		rs5c->regs[RS5C_REG_CTRL1] = buf;
313
314	return status;
315}
316
317
318/* NOTE:  Since RTC_WKALM_{RD,SET} were originally defined for EFI,
319 * which only exposes a polled programming interface; and since
320 * these calls map directly to those EFI requests; we don't demand
321 * we have an IRQ for this chip when we go through this API.
322 *
323 * The older x86_pc derived RTC_ALM_{READ,SET} calls require irqs
324 * though, managed through RTC_AIE_{ON,OFF} requests.
325 */
326
327static int rs5c_read_alarm(struct device *dev, struct rtc_wkalrm *t)
328{
329	struct i2c_client	*client = to_i2c_client(dev);
330	struct rs5c372		*rs5c = i2c_get_clientdata(client);
331	int			status;
332
333	status = rs5c_get_regs(rs5c);
334	if (status < 0)
335		return status;
336
337	/* report alarm time */
338	t->time.tm_sec = 0;
339	t->time.tm_min = bcd2bin(rs5c->regs[RS5C_REG_ALARM_A_MIN] & 0x7f);
340	t->time.tm_hour = rs5c_reg2hr(rs5c, rs5c->regs[RS5C_REG_ALARM_A_HOURS]);
341	t->time.tm_mday = -1;
342	t->time.tm_mon = -1;
343	t->time.tm_year = -1;
344	t->time.tm_wday = -1;
345	t->time.tm_yday = -1;
346	t->time.tm_isdst = -1;
347
348	/* ... and status */
349	t->enabled = !!(rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE);
350	t->pending = !!(rs5c->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_AAFG);
351
352	return 0;
353}
354
355static int rs5c_set_alarm(struct device *dev, struct rtc_wkalrm *t)
356{
357	struct i2c_client	*client = to_i2c_client(dev);
358	struct rs5c372		*rs5c = i2c_get_clientdata(client);
359	int			status, addr, i;
360	unsigned char		buf[3];
361
362	/* only handle up to 24 hours in the future, like RTC_ALM_SET */
363	if (t->time.tm_mday != -1
364			|| t->time.tm_mon != -1
365			|| t->time.tm_year != -1)
366		return -EINVAL;
367
368	/* REVISIT: round up tm_sec */
369
370	/* if needed, disable irq (clears pending status) */
371	status = rs5c_get_regs(rs5c);
372	if (status < 0)
373		return status;
374	if (rs5c->regs[RS5C_REG_CTRL1] & RS5C_CTRL1_AALE) {
375		addr = RS5C_ADDR(RS5C_REG_CTRL1);
376		buf[0] = rs5c->regs[RS5C_REG_CTRL1] & ~RS5C_CTRL1_AALE;
377		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0) {
378			pr_debug("%s: can't disable alarm\n", rs5c->rtc->name);
379			return -EIO;
380		}
381		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
382	}
383
384	/* set alarm */
385	buf[0] = bin2bcd(t->time.tm_min);
386	buf[1] = rs5c_hr2reg(rs5c, t->time.tm_hour);
387	buf[2] = 0x7f;	/* any/all days */
388
389	for (i = 0; i < sizeof(buf); i++) {
390		addr = RS5C_ADDR(RS5C_REG_ALARM_A_MIN + i);
391		if (i2c_smbus_write_byte_data(client, addr, buf[i]) < 0) {
392			pr_debug("%s: can't set alarm time\n", rs5c->rtc->name);
393			return -EIO;
394		}
395	}
396
397	/* ... and maybe enable its irq */
398	if (t->enabled) {
399		addr = RS5C_ADDR(RS5C_REG_CTRL1);
400		buf[0] = rs5c->regs[RS5C_REG_CTRL1] | RS5C_CTRL1_AALE;
401		if (i2c_smbus_write_byte_data(client, addr, buf[0]) < 0)
402			printk(KERN_WARNING "%s: can't enable alarm\n",
403				rs5c->rtc->name);
404		rs5c->regs[RS5C_REG_CTRL1] = buf[0];
405	}
406
407	return 0;
408}
409
410#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
411
412static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
413{
414	int err, osc, trim;
415
416	err = rs5c372_get_trim(to_i2c_client(dev), &osc, &trim);
417	if (err == 0) {
418		seq_printf(seq, "crystal\t\t: %d.%03d KHz\n",
419				osc / 1000, osc % 1000);
420		seq_printf(seq, "trim\t\t: %d\n", trim);
421	}
422
423	return 0;
424}
425
426#else
427#define	rs5c372_rtc_proc	NULL
428#endif
429
430static const struct rtc_class_ops rs5c372_rtc_ops = {
431	.proc		= rs5c372_rtc_proc,
432	.read_time	= rs5c372_rtc_read_time,
433	.set_time	= rs5c372_rtc_set_time,
434	.read_alarm	= rs5c_read_alarm,
435	.set_alarm	= rs5c_set_alarm,
436	.alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
437};
438
439#if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE)
440
441static ssize_t rs5c372_sysfs_show_trim(struct device *dev,
442				struct device_attribute *attr, char *buf)
443{
444	int err, trim;
445
446	err = rs5c372_get_trim(to_i2c_client(dev), NULL, &trim);
447	if (err)
448		return err;
449
450	return sprintf(buf, "%d\n", trim);
451}
452static DEVICE_ATTR(trim, S_IRUGO, rs5c372_sysfs_show_trim, NULL);
453
454static ssize_t rs5c372_sysfs_show_osc(struct device *dev,
455				struct device_attribute *attr, char *buf)
456{
457	int err, osc;
458
459	err = rs5c372_get_trim(to_i2c_client(dev), &osc, NULL);
460	if (err)
461		return err;
462
463	return sprintf(buf, "%d.%03d KHz\n", osc / 1000, osc % 1000);
464}
465static DEVICE_ATTR(osc, S_IRUGO, rs5c372_sysfs_show_osc, NULL);
466
467static int rs5c_sysfs_register(struct device *dev)
468{
469	int err;
470
471	err = device_create_file(dev, &dev_attr_trim);
472	if (err)
473		return err;
474	err = device_create_file(dev, &dev_attr_osc);
475	if (err)
476		device_remove_file(dev, &dev_attr_trim);
477
478	return err;
479}
480
481static void rs5c_sysfs_unregister(struct device *dev)
482{
483	device_remove_file(dev, &dev_attr_trim);
484	device_remove_file(dev, &dev_attr_osc);
485}
486
487#else
488static int rs5c_sysfs_register(struct device *dev)
489{
490	return 0;
491}
492
493static void rs5c_sysfs_unregister(struct device *dev)
494{
495	/* nothing */
496}
497#endif	/* SYSFS */
498
499static struct i2c_driver rs5c372_driver;
500
501static int rs5c_oscillator_setup(struct rs5c372 *rs5c372)
502{
503	unsigned char buf[2];
504	int addr, i, ret = 0;
505
506	if (rs5c372->type == rtc_r2025sd) {
507		if (!(rs5c372->regs[RS5C_REG_CTRL2] & R2025_CTRL2_XST))
508			return ret;
509		rs5c372->regs[RS5C_REG_CTRL2] &= ~R2025_CTRL2_XST;
510	} else {
511		if (!(rs5c372->regs[RS5C_REG_CTRL2] & RS5C_CTRL2_XSTP))
512			return ret;
513		rs5c372->regs[RS5C_REG_CTRL2] &= ~RS5C_CTRL2_XSTP;
514	}
515
516	addr   = RS5C_ADDR(RS5C_REG_CTRL1);
517	buf[0] = rs5c372->regs[RS5C_REG_CTRL1];
518	buf[1] = rs5c372->regs[RS5C_REG_CTRL2];
519
520	/* use 24hr mode */
521	switch (rs5c372->type) {
522	case rtc_rs5c372a:
523	case rtc_rs5c372b:
524		buf[1] |= RS5C372_CTRL2_24;
525		rs5c372->time24 = 1;
526		break;
527	case rtc_r2025sd:
 
528	case rtc_rv5c386:
529	case rtc_rv5c387a:
530		buf[0] |= RV5C387_CTRL1_24;
531		rs5c372->time24 = 1;
532		break;
533	default:
534		/* impossible */
535		break;
536	}
537
538	for (i = 0; i < sizeof(buf); i++) {
539		addr = RS5C_ADDR(RS5C_REG_CTRL1 + i);
540		ret = i2c_smbus_write_byte_data(rs5c372->client, addr, buf[i]);
541		if (unlikely(ret < 0))
542			return ret;
543	}
544
545	rs5c372->regs[RS5C_REG_CTRL1] = buf[0];
546	rs5c372->regs[RS5C_REG_CTRL2] = buf[1];
547
548	return 0;
549}
550
551static int rs5c372_probe(struct i2c_client *client,
552			 const struct i2c_device_id *id)
553{
554	int err = 0;
555	int smbus_mode = 0;
556	struct rs5c372 *rs5c372;
557	struct rtc_time tm;
558
559	dev_dbg(&client->dev, "%s\n", __func__);
560
561	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
562			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) {
563		/*
564		 * If we don't have any master mode adapter, try breaking
565		 * it down in to the barest of capabilities.
566		 */
567		if (i2c_check_functionality(client->adapter,
568				I2C_FUNC_SMBUS_BYTE_DATA |
569				I2C_FUNC_SMBUS_I2C_BLOCK))
570			smbus_mode = 1;
571		else {
572			/* Still no good, give up */
573			err = -ENODEV;
574			goto exit;
575		}
576	}
577
578	if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {
 
 
579		err = -ENOMEM;
580		goto exit;
581	}
582
583	rs5c372->client = client;
584	i2c_set_clientdata(client, rs5c372);
585	rs5c372->type = id->driver_data;
 
 
 
 
586
587	/* we read registers 0x0f then 0x00-0x0f; skip the first one */
588	rs5c372->regs = &rs5c372->buf[1];
589	rs5c372->smbus = smbus_mode;
590
591	err = rs5c_get_regs(rs5c372);
592	if (err < 0)
593		goto exit_kfree;
594
595	/* clock may be set for am/pm or 24 hr time */
596	switch (rs5c372->type) {
597	case rtc_rs5c372a:
598	case rtc_rs5c372b:
599		/* alarm uses ALARM_A; and nINTRA on 372a, nINTR on 372b.
600		 * so does periodic irq, except some 327a modes.
601		 */
602		if (rs5c372->regs[RS5C_REG_CTRL2] & RS5C372_CTRL2_24)
603			rs5c372->time24 = 1;
604		break;
605	case rtc_r2025sd:
 
606	case rtc_rv5c386:
607	case rtc_rv5c387a:
608		if (rs5c372->regs[RS5C_REG_CTRL1] & RV5C387_CTRL1_24)
609			rs5c372->time24 = 1;
610		/* alarm uses ALARM_W; and nINTRB for alarm and periodic
611		 * irq, on both 386 and 387
612		 */
613		break;
614	default:
615		dev_err(&client->dev, "unknown RTC type\n");
616		goto exit_kfree;
617	}
618
619	/* if the oscillator lost power and no other software (like
620	 * the bootloader) set it up, do it here.
621	 *
622	 * The R2025S/D does this a little differently than the other
623	 * parts, so we special case that..
624	 */
625	err = rs5c_oscillator_setup(rs5c372);
626	if (unlikely(err < 0)) {
627		dev_err(&client->dev, "setup error\n");
628		goto exit_kfree;
629	}
630
631	if (rs5c372_get_datetime(client, &tm) < 0)
632		dev_warn(&client->dev, "clock needs to be set\n");
633
634	dev_info(&client->dev, "%s found, %s, driver version " DRV_VERSION "\n",
635			({ char *s; switch (rs5c372->type) {
636			case rtc_r2025sd:	s = "r2025sd"; break;
 
637			case rtc_rs5c372a:	s = "rs5c372a"; break;
638			case rtc_rs5c372b:	s = "rs5c372b"; break;
639			case rtc_rv5c386:	s = "rv5c386"; break;
640			case rtc_rv5c387a:	s = "rv5c387a"; break;
641			default:		s = "chip"; break;
642			}; s;}),
643			rs5c372->time24 ? "24hr" : "am/pm"
644			);
645
646	/* REVISIT use client->irq to register alarm irq ... */
647
648	rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,
649				&client->dev, &rs5c372_rtc_ops, THIS_MODULE);
650
651	if (IS_ERR(rs5c372->rtc)) {
652		err = PTR_ERR(rs5c372->rtc);
653		goto exit_kfree;
654	}
655
656	err = rs5c_sysfs_register(&client->dev);
657	if (err)
658		goto exit_devreg;
659
660	return 0;
661
662exit_devreg:
663	rtc_device_unregister(rs5c372->rtc);
664
665exit_kfree:
666	kfree(rs5c372);
667
668exit:
669	return err;
670}
671
672static int rs5c372_remove(struct i2c_client *client)
673{
674	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);
675
676	rtc_device_unregister(rs5c372->rtc);
677	rs5c_sysfs_unregister(&client->dev);
678	kfree(rs5c372);
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
691static __init int rs5c372_init(void)
692{
693	return i2c_add_driver(&rs5c372_driver);
694}
695
696static __exit void rs5c372_exit(void)
697{
698	i2c_del_driver(&rs5c372_driver);
699}
700
701module_init(rs5c372_init);
702module_exit(rs5c372_exit);
703
704MODULE_AUTHOR(
705		"Pavel Mironchik <pmironchik@optifacio.net>, "
706		"Alessandro Zummo <a.zummo@towertech.it>, "
707		"Paul Mundt <lethal@linux-sh.org>");
708MODULE_DESCRIPTION("Ricoh RS5C372 RTC driver");
709MODULE_LICENSE("GPL");
710MODULE_VERSION(DRV_VERSION);