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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * A driver for the I2C members of the Abracon AB x8xx RTC family,
  4 * and compatible: AB 1805 and AB 0805
  5 *
  6 * Copyright 2014-2015 Macq S.A.
  7 *
  8 * Author: Philippe De Muyter <phdm@macqel.be>
  9 * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
 10 *
 11 */
 12
 13#include <linux/bcd.h>
 14#include <linux/i2c.h>
 15#include <linux/module.h>
 16#include <linux/of_device.h>
 17#include <linux/rtc.h>
 18#include <linux/watchdog.h>
 19
 20#define ABX8XX_REG_HTH		0x00
 21#define ABX8XX_REG_SC		0x01
 22#define ABX8XX_REG_MN		0x02
 23#define ABX8XX_REG_HR		0x03
 24#define ABX8XX_REG_DA		0x04
 25#define ABX8XX_REG_MO		0x05
 26#define ABX8XX_REG_YR		0x06
 27#define ABX8XX_REG_WD		0x07
 28
 29#define ABX8XX_REG_AHTH		0x08
 30#define ABX8XX_REG_ASC		0x09
 31#define ABX8XX_REG_AMN		0x0a
 32#define ABX8XX_REG_AHR		0x0b
 33#define ABX8XX_REG_ADA		0x0c
 34#define ABX8XX_REG_AMO		0x0d
 35#define ABX8XX_REG_AWD		0x0e
 36
 37#define ABX8XX_REG_STATUS	0x0f
 38#define ABX8XX_STATUS_AF	BIT(2)
 39#define ABX8XX_STATUS_BLF	BIT(4)
 40#define ABX8XX_STATUS_WDT	BIT(6)
 41
 42#define ABX8XX_REG_CTRL1	0x10
 43#define ABX8XX_CTRL_WRITE	BIT(0)
 44#define ABX8XX_CTRL_ARST	BIT(2)
 45#define ABX8XX_CTRL_12_24	BIT(6)
 46
 47#define ABX8XX_REG_CTRL2	0x11
 48#define ABX8XX_CTRL2_RSVD	BIT(5)
 49
 50#define ABX8XX_REG_IRQ		0x12
 51#define ABX8XX_IRQ_AIE		BIT(2)
 52#define ABX8XX_IRQ_IM_1_4	(0x3 << 5)
 53
 54#define ABX8XX_REG_CD_TIMER_CTL	0x18
 55
 56#define ABX8XX_REG_OSC		0x1c
 57#define ABX8XX_OSC_FOS		BIT(3)
 58#define ABX8XX_OSC_BOS		BIT(4)
 59#define ABX8XX_OSC_ACAL_512	BIT(5)
 60#define ABX8XX_OSC_ACAL_1024	BIT(6)
 61
 62#define ABX8XX_OSC_OSEL		BIT(7)
 63
 64#define ABX8XX_REG_OSS		0x1d
 65#define ABX8XX_OSS_OF		BIT(1)
 66#define ABX8XX_OSS_OMODE	BIT(4)
 67
 68#define ABX8XX_REG_WDT		0x1b
 69#define ABX8XX_WDT_WDS		BIT(7)
 70#define ABX8XX_WDT_BMB_MASK	0x7c
 71#define ABX8XX_WDT_BMB_SHIFT	2
 72#define ABX8XX_WDT_MAX_TIME	(ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
 73#define ABX8XX_WDT_WRB_MASK	0x03
 74#define ABX8XX_WDT_WRB_1HZ	0x02
 75
 76#define ABX8XX_REG_CFG_KEY	0x1f
 77#define ABX8XX_CFG_KEY_OSC	0xa1
 78#define ABX8XX_CFG_KEY_MISC	0x9d
 79
 80#define ABX8XX_REG_ID0		0x28
 81
 82#define ABX8XX_REG_OUT_CTRL	0x30
 83#define ABX8XX_OUT_CTRL_EXDS	BIT(4)
 84
 85#define ABX8XX_REG_TRICKLE	0x20
 86#define ABX8XX_TRICKLE_CHARGE_ENABLE	0xa0
 87#define ABX8XX_TRICKLE_STANDARD_DIODE	0x8
 88#define ABX8XX_TRICKLE_SCHOTTKY_DIODE	0x4
 89
 90static u8 trickle_resistors[] = {0, 3, 6, 11};
 91
 92enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
 93	AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
 94
 95struct abx80x_cap {
 96	u16 pn;
 97	bool has_tc;
 98	bool has_wdog;
 99};
100
101static struct abx80x_cap abx80x_caps[] = {
102	[AB0801] = {.pn = 0x0801},
103	[AB0803] = {.pn = 0x0803},
104	[AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
105	[AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
106	[AB1801] = {.pn = 0x1801},
107	[AB1803] = {.pn = 0x1803},
108	[AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
109	[AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
110	[RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
111	[ABX80X] = {.pn = 0}
112};
113
114struct abx80x_priv {
115	struct rtc_device *rtc;
116	struct i2c_client *client;
117	struct watchdog_device wdog;
118};
119
120static int abx80x_write_config_key(struct i2c_client *client, u8 key)
121{
122	if (i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, key) < 0) {
123		dev_err(&client->dev, "Unable to write configuration key\n");
124		return -EIO;
125	}
126
127	return 0;
128}
129
130static int abx80x_is_rc_mode(struct i2c_client *client)
131{
132	int flags = 0;
133
134	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
135	if (flags < 0) {
136		dev_err(&client->dev,
137			"Failed to read autocalibration attribute\n");
138		return flags;
139	}
140
141	return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
142}
143
144static int abx80x_enable_trickle_charger(struct i2c_client *client,
145					 u8 trickle_cfg)
146{
147	int err;
148
149	/*
150	 * Write the configuration key register to enable access to the Trickle
151	 * register
152	 */
153	if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
154		return -EIO;
155
156	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
157					ABX8XX_TRICKLE_CHARGE_ENABLE |
158					trickle_cfg);
159	if (err < 0) {
160		dev_err(&client->dev, "Unable to write trickle register\n");
161		return -EIO;
162	}
163
164	return 0;
165}
166
167static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
168{
169	struct i2c_client *client = to_i2c_client(dev);
170	unsigned char buf[8];
171	int err, flags, rc_mode = 0;
172
173	/* Read the Oscillator Failure only in XT mode */
174	rc_mode = abx80x_is_rc_mode(client);
175	if (rc_mode < 0)
176		return rc_mode;
177
178	if (!rc_mode) {
179		flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
180		if (flags < 0)
181			return flags;
182
183		if (flags & ABX8XX_OSS_OF) {
184			dev_err(dev, "Oscillator failure, data is invalid.\n");
185			return -EINVAL;
186		}
187	}
188
189	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
190					    sizeof(buf), buf);
191	if (err < 0) {
192		dev_err(&client->dev, "Unable to read date\n");
193		return -EIO;
194	}
195
196	tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
197	tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
198	tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
199	tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
200	tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
201	tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
202	tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
203
204	return 0;
205}
206
207static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
208{
209	struct i2c_client *client = to_i2c_client(dev);
210	unsigned char buf[8];
211	int err, flags;
212
213	if (tm->tm_year < 100)
214		return -EINVAL;
215
216	buf[ABX8XX_REG_HTH] = 0;
217	buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
218	buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
219	buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
220	buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
221	buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
222	buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
223	buf[ABX8XX_REG_WD] = tm->tm_wday;
224
225	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
226					     sizeof(buf), buf);
227	if (err < 0) {
228		dev_err(&client->dev, "Unable to write to date registers\n");
229		return -EIO;
230	}
231
232	/* Clear the OF bit of Oscillator Status Register */
233	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
234	if (flags < 0)
235		return flags;
236
237	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
238					flags & ~ABX8XX_OSS_OF);
239	if (err < 0) {
240		dev_err(&client->dev, "Unable to write oscillator status register\n");
241		return err;
242	}
243
244	return 0;
245}
246
247static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
248{
249	struct i2c_client *client = dev_id;
250	struct abx80x_priv *priv = i2c_get_clientdata(client);
251	struct rtc_device *rtc = priv->rtc;
252	int status;
253
254	status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
255	if (status < 0)
256		return IRQ_NONE;
257
258	if (status & ABX8XX_STATUS_AF)
259		rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
260
261	/*
262	 * It is unclear if we'll get an interrupt before the external
263	 * reset kicks in.
264	 */
265	if (status & ABX8XX_STATUS_WDT)
266		dev_alert(&client->dev, "watchdog timeout interrupt.\n");
267
268	i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
269
270	return IRQ_HANDLED;
271}
272
273static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
274{
275	struct i2c_client *client = to_i2c_client(dev);
276	unsigned char buf[7];
277
278	int irq_mask, err;
279
280	if (client->irq <= 0)
281		return -EINVAL;
282
283	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
284					    sizeof(buf), buf);
285	if (err)
286		return err;
287
288	irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
289	if (irq_mask < 0)
290		return irq_mask;
291
292	t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
293	t->time.tm_min = bcd2bin(buf[1] & 0x7F);
294	t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
295	t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
296	t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
297	t->time.tm_wday = buf[5] & 0x7;
298
299	t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
300	t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
301
302	return err;
303}
304
305static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
306{
307	struct i2c_client *client = to_i2c_client(dev);
308	u8 alarm[6];
309	int err;
310
311	if (client->irq <= 0)
312		return -EINVAL;
313
314	alarm[0] = 0x0;
315	alarm[1] = bin2bcd(t->time.tm_sec);
316	alarm[2] = bin2bcd(t->time.tm_min);
317	alarm[3] = bin2bcd(t->time.tm_hour);
318	alarm[4] = bin2bcd(t->time.tm_mday);
319	alarm[5] = bin2bcd(t->time.tm_mon + 1);
320
321	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
322					     sizeof(alarm), alarm);
323	if (err < 0) {
324		dev_err(&client->dev, "Unable to write alarm registers\n");
325		return -EIO;
326	}
327
328	if (t->enabled) {
329		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
330						(ABX8XX_IRQ_IM_1_4 |
331						 ABX8XX_IRQ_AIE));
332		if (err)
333			return err;
334	}
335
336	return 0;
337}
338
339static int abx80x_rtc_set_autocalibration(struct device *dev,
340					  int autocalibration)
341{
342	struct i2c_client *client = to_i2c_client(dev);
343	int retval, flags = 0;
344
345	if ((autocalibration != 0) && (autocalibration != 1024) &&
346	    (autocalibration != 512)) {
347		dev_err(dev, "autocalibration value outside permitted range\n");
348		return -EINVAL;
349	}
350
351	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
352	if (flags < 0)
353		return flags;
354
355	if (autocalibration == 0) {
356		flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
357	} else if (autocalibration == 1024) {
358		/* 1024 autocalibration is 0x10 */
359		flags |= ABX8XX_OSC_ACAL_1024;
360		flags &= ~(ABX8XX_OSC_ACAL_512);
361	} else {
362		/* 512 autocalibration is 0x11 */
363		flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
364	}
365
366	/* Unlock write access to Oscillator Control Register */
367	if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
368		return -EIO;
369
370	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
371
372	return retval;
373}
374
375static int abx80x_rtc_get_autocalibration(struct device *dev)
376{
377	struct i2c_client *client = to_i2c_client(dev);
378	int flags = 0, autocalibration;
379
380	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
381	if (flags < 0)
382		return flags;
383
384	if (flags & ABX8XX_OSC_ACAL_512)
385		autocalibration = 512;
386	else if (flags & ABX8XX_OSC_ACAL_1024)
387		autocalibration = 1024;
388	else
389		autocalibration = 0;
390
391	return autocalibration;
392}
393
394static ssize_t autocalibration_store(struct device *dev,
395				     struct device_attribute *attr,
396				     const char *buf, size_t count)
397{
398	int retval;
399	unsigned long autocalibration = 0;
400
401	retval = kstrtoul(buf, 10, &autocalibration);
402	if (retval < 0) {
403		dev_err(dev, "Failed to store RTC autocalibration attribute\n");
404		return -EINVAL;
405	}
406
407	retval = abx80x_rtc_set_autocalibration(dev->parent, autocalibration);
408
409	return retval ? retval : count;
410}
411
412static ssize_t autocalibration_show(struct device *dev,
413				    struct device_attribute *attr, char *buf)
414{
415	int autocalibration = 0;
416
417	autocalibration = abx80x_rtc_get_autocalibration(dev->parent);
418	if (autocalibration < 0) {
419		dev_err(dev, "Failed to read RTC autocalibration\n");
420		sprintf(buf, "0\n");
421		return autocalibration;
422	}
423
424	return sprintf(buf, "%d\n", autocalibration);
425}
426
427static DEVICE_ATTR_RW(autocalibration);
428
429static ssize_t oscillator_store(struct device *dev,
430				struct device_attribute *attr,
431				const char *buf, size_t count)
432{
433	struct i2c_client *client = to_i2c_client(dev->parent);
434	int retval, flags, rc_mode = 0;
435
436	if (strncmp(buf, "rc", 2) == 0) {
437		rc_mode = 1;
438	} else if (strncmp(buf, "xtal", 4) == 0) {
439		rc_mode = 0;
440	} else {
441		dev_err(dev, "Oscillator selection value outside permitted ones\n");
442		return -EINVAL;
443	}
444
445	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
446	if (flags < 0)
447		return flags;
448
449	if (rc_mode == 0)
450		flags &= ~(ABX8XX_OSC_OSEL);
451	else
452		flags |= (ABX8XX_OSC_OSEL);
453
454	/* Unlock write access on Oscillator Control register */
455	if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
456		return -EIO;
457
458	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
459	if (retval < 0) {
460		dev_err(dev, "Failed to write Oscillator Control register\n");
461		return retval;
462	}
463
464	return retval ? retval : count;
465}
466
467static ssize_t oscillator_show(struct device *dev,
468			       struct device_attribute *attr, char *buf)
469{
470	int rc_mode = 0;
471	struct i2c_client *client = to_i2c_client(dev->parent);
472
473	rc_mode = abx80x_is_rc_mode(client);
474
475	if (rc_mode < 0) {
476		dev_err(dev, "Failed to read RTC oscillator selection\n");
477		sprintf(buf, "\n");
478		return rc_mode;
479	}
480
481	if (rc_mode)
482		return sprintf(buf, "rc\n");
483	else
484		return sprintf(buf, "xtal\n");
485}
486
487static DEVICE_ATTR_RW(oscillator);
488
489static struct attribute *rtc_calib_attrs[] = {
490	&dev_attr_autocalibration.attr,
491	&dev_attr_oscillator.attr,
492	NULL,
493};
494
495static const struct attribute_group rtc_calib_attr_group = {
496	.attrs		= rtc_calib_attrs,
497};
498
499static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
500{
501	struct i2c_client *client = to_i2c_client(dev);
502	int err;
503
504	if (enabled)
505		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
506						(ABX8XX_IRQ_IM_1_4 |
507						 ABX8XX_IRQ_AIE));
508	else
509		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
510						ABX8XX_IRQ_IM_1_4);
511	return err;
512}
513
514static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
515{
516	struct i2c_client *client = to_i2c_client(dev);
517	int status, tmp;
518
519	switch (cmd) {
520	case RTC_VL_READ:
521		status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
522		if (status < 0)
523			return status;
524
525		tmp = status & ABX8XX_STATUS_BLF ? RTC_VL_BACKUP_LOW : 0;
526
527		return put_user(tmp, (unsigned int __user *)arg);
528
529	case RTC_VL_CLR:
530		status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
531		if (status < 0)
532			return status;
533
534		status &= ~ABX8XX_STATUS_BLF;
535
536		tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
537		if (tmp < 0)
538			return tmp;
539
540		return 0;
541
542	default:
543		return -ENOIOCTLCMD;
544	}
545}
546
547static const struct rtc_class_ops abx80x_rtc_ops = {
548	.read_time	= abx80x_rtc_read_time,
549	.set_time	= abx80x_rtc_set_time,
550	.read_alarm	= abx80x_read_alarm,
551	.set_alarm	= abx80x_set_alarm,
552	.alarm_irq_enable = abx80x_alarm_irq_enable,
553	.ioctl		= abx80x_ioctl,
554};
555
556static int abx80x_dt_trickle_cfg(struct i2c_client *client)
557{
558	struct device_node *np = client->dev.of_node;
559	const char *diode;
560	int trickle_cfg = 0;
561	int i, ret;
562	u32 tmp;
563
564	ret = of_property_read_string(np, "abracon,tc-diode", &diode);
565	if (ret)
566		return ret;
567
568	if (!strcmp(diode, "standard")) {
569		trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
570	} else if (!strcmp(diode, "schottky")) {
571		trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
572	} else {
573		dev_dbg(&client->dev, "Invalid tc-diode value: %s\n", diode);
574		return -EINVAL;
575	}
576
577	ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
578	if (ret)
579		return ret;
580
581	for (i = 0; i < sizeof(trickle_resistors); i++)
582		if (trickle_resistors[i] == tmp)
583			break;
584
585	if (i == sizeof(trickle_resistors)) {
586		dev_dbg(&client->dev, "Invalid tc-resistor value: %u\n", tmp);
587		return -EINVAL;
588	}
589
590	return (trickle_cfg | i);
591}
592
593#ifdef CONFIG_WATCHDOG
594
595static inline u8 timeout_bits(unsigned int timeout)
596{
597	return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
598		 ABX8XX_WDT_WRB_1HZ;
599}
600
601static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
602				     unsigned int timeout)
603{
604	struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
605	u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
606
607	/*
608	 * Writing any timeout to the WDT register resets the watchdog timer.
609	 * Writing 0 disables it.
610	 */
611	return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
612}
613
614static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
615				   unsigned int new_timeout)
616{
617	int err = 0;
618
619	if (watchdog_hw_running(wdog))
620		err = __abx80x_wdog_set_timeout(wdog, new_timeout);
621
622	if (err == 0)
623		wdog->timeout = new_timeout;
624
625	return err;
626}
627
628static int abx80x_wdog_ping(struct watchdog_device *wdog)
629{
630	return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
631}
632
633static int abx80x_wdog_start(struct watchdog_device *wdog)
634{
635	return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
636}
637
638static int abx80x_wdog_stop(struct watchdog_device *wdog)
639{
640	return __abx80x_wdog_set_timeout(wdog, 0);
641}
642
643static const struct watchdog_info abx80x_wdog_info = {
644	.identity = "abx80x watchdog",
645	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
646};
647
648static const struct watchdog_ops abx80x_wdog_ops = {
649	.owner = THIS_MODULE,
650	.start = abx80x_wdog_start,
651	.stop = abx80x_wdog_stop,
652	.ping = abx80x_wdog_ping,
653	.set_timeout = abx80x_wdog_set_timeout,
654};
655
656static int abx80x_setup_watchdog(struct abx80x_priv *priv)
657{
658	priv->wdog.parent = &priv->client->dev;
659	priv->wdog.ops = &abx80x_wdog_ops;
660	priv->wdog.info = &abx80x_wdog_info;
661	priv->wdog.min_timeout = 1;
662	priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
663	priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
664
665	watchdog_set_drvdata(&priv->wdog, priv);
666
667	return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
668}
669#else
670static int abx80x_setup_watchdog(struct abx80x_priv *priv)
671{
672	return 0;
673}
674#endif
675
676static int abx80x_probe(struct i2c_client *client,
677			const struct i2c_device_id *id)
678{
679	struct device_node *np = client->dev.of_node;
680	struct abx80x_priv *priv;
681	int i, data, err, trickle_cfg = -EINVAL;
682	char buf[7];
683	unsigned int part = id->driver_data;
684	unsigned int partnumber;
685	unsigned int majrev, minrev;
686	unsigned int lot;
687	unsigned int wafer;
688	unsigned int uid;
689
690	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
691		return -ENODEV;
692
693	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
694					    sizeof(buf), buf);
695	if (err < 0) {
696		dev_err(&client->dev, "Unable to read partnumber\n");
697		return -EIO;
698	}
699
700	partnumber = (buf[0] << 8) | buf[1];
701	majrev = buf[2] >> 3;
702	minrev = buf[2] & 0x7;
703	lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
704	uid = ((buf[4] & 0x7f) << 8) | buf[5];
705	wafer = (buf[6] & 0x7c) >> 2;
706	dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
707		 partnumber, majrev, minrev, lot, wafer, uid);
708
709	data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
710	if (data < 0) {
711		dev_err(&client->dev, "Unable to read control register\n");
712		return -EIO;
713	}
714
715	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
716					((data & ~(ABX8XX_CTRL_12_24 |
717						   ABX8XX_CTRL_ARST)) |
718					 ABX8XX_CTRL_WRITE));
719	if (err < 0) {
720		dev_err(&client->dev, "Unable to write control register\n");
721		return -EIO;
722	}
723
724	/* Configure RV1805 specifics */
725	if (part == RV1805) {
726		/*
727		 * Avoid accidentally entering test mode. This can happen
728		 * on the RV1805 in case the reserved bit 5 in control2
729		 * register is set. RV-1805-C3 datasheet indicates that
730		 * the bit should be cleared in section 11h - Control2.
731		 */
732		data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
733		if (data < 0) {
734			dev_err(&client->dev,
735				"Unable to read control2 register\n");
736			return -EIO;
737		}
738
739		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
740						data & ~ABX8XX_CTRL2_RSVD);
741		if (err < 0) {
742			dev_err(&client->dev,
743				"Unable to write control2 register\n");
744			return -EIO;
745		}
746
747		/*
748		 * Avoid extra power leakage. The RV1805 uses smaller
749		 * 10pin package and the EXTI input is not present.
750		 * Disable it to avoid leakage.
751		 */
752		data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
753		if (data < 0) {
754			dev_err(&client->dev,
755				"Unable to read output control register\n");
756			return -EIO;
757		}
758
759		/*
760		 * Write the configuration key register to enable access to
761		 * the config2 register
762		 */
763		if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
764			return -EIO;
765
766		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
767						data | ABX8XX_OUT_CTRL_EXDS);
768		if (err < 0) {
769			dev_err(&client->dev,
770				"Unable to write output control register\n");
771			return -EIO;
772		}
773	}
774
775	/* part autodetection */
776	if (part == ABX80X) {
777		for (i = 0; abx80x_caps[i].pn; i++)
778			if (partnumber == abx80x_caps[i].pn)
779				break;
780		if (abx80x_caps[i].pn == 0) {
781			dev_err(&client->dev, "Unknown part: %04x\n",
782				partnumber);
783			return -EINVAL;
784		}
785		part = i;
786	}
787
788	if (partnumber != abx80x_caps[part].pn) {
789		dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
790			partnumber, abx80x_caps[part].pn);
791		return -EINVAL;
792	}
793
794	if (np && abx80x_caps[part].has_tc)
795		trickle_cfg = abx80x_dt_trickle_cfg(client);
796
797	if (trickle_cfg > 0) {
798		dev_info(&client->dev, "Enabling trickle charger: %02x\n",
799			 trickle_cfg);
800		abx80x_enable_trickle_charger(client, trickle_cfg);
801	}
802
803	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
804					BIT(2));
805	if (err)
806		return err;
807
808	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
809	if (priv == NULL)
810		return -ENOMEM;
811
812	priv->rtc = devm_rtc_allocate_device(&client->dev);
813	if (IS_ERR(priv->rtc))
814		return PTR_ERR(priv->rtc);
815
816	priv->rtc->ops = &abx80x_rtc_ops;
817	priv->client = client;
818
819	i2c_set_clientdata(client, priv);
820
821	if (abx80x_caps[part].has_wdog) {
822		err = abx80x_setup_watchdog(priv);
823		if (err)
824			return err;
825	}
826
827	if (client->irq > 0) {
828		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
829		err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
830						abx80x_handle_irq,
831						IRQF_SHARED | IRQF_ONESHOT,
832						"abx8xx",
833						client);
834		if (err) {
835			dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
836			client->irq = 0;
837		}
838	}
839
840	err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
841	if (err) {
842		dev_err(&client->dev, "Failed to create sysfs group: %d\n",
843			err);
844		return err;
845	}
846
847	return devm_rtc_register_device(priv->rtc);
848}
849
850static const struct i2c_device_id abx80x_id[] = {
851	{ "abx80x", ABX80X },
852	{ "ab0801", AB0801 },
853	{ "ab0803", AB0803 },
854	{ "ab0804", AB0804 },
855	{ "ab0805", AB0805 },
856	{ "ab1801", AB1801 },
857	{ "ab1803", AB1803 },
858	{ "ab1804", AB1804 },
859	{ "ab1805", AB1805 },
860	{ "rv1805", RV1805 },
861	{ }
862};
863MODULE_DEVICE_TABLE(i2c, abx80x_id);
864
865#ifdef CONFIG_OF
866static const struct of_device_id abx80x_of_match[] = {
867	{
868		.compatible = "abracon,abx80x",
869		.data = (void *)ABX80X
870	},
871	{
872		.compatible = "abracon,ab0801",
873		.data = (void *)AB0801
874	},
875	{
876		.compatible = "abracon,ab0803",
877		.data = (void *)AB0803
878	},
879	{
880		.compatible = "abracon,ab0804",
881		.data = (void *)AB0804
882	},
883	{
884		.compatible = "abracon,ab0805",
885		.data = (void *)AB0805
886	},
887	{
888		.compatible = "abracon,ab1801",
889		.data = (void *)AB1801
890	},
891	{
892		.compatible = "abracon,ab1803",
893		.data = (void *)AB1803
894	},
895	{
896		.compatible = "abracon,ab1804",
897		.data = (void *)AB1804
898	},
899	{
900		.compatible = "abracon,ab1805",
901		.data = (void *)AB1805
902	},
903	{
904		.compatible = "microcrystal,rv1805",
905		.data = (void *)RV1805
906	},
907	{ }
908};
909MODULE_DEVICE_TABLE(of, abx80x_of_match);
910#endif
911
912static struct i2c_driver abx80x_driver = {
913	.driver		= {
914		.name	= "rtc-abx80x",
915		.of_match_table = of_match_ptr(abx80x_of_match),
916	},
917	.probe		= abx80x_probe,
918	.id_table	= abx80x_id,
919};
920
921module_i2c_driver(abx80x_driver);
922
923MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
924MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
925MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
926MODULE_LICENSE("GPL v2");