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/bitfield.h>
15#include <linux/i2c.h>
16#include <linux/kstrtox.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/rtc.h>
20#include <linux/watchdog.h>
21
22#define ABX8XX_REG_HTH		0x00
23#define ABX8XX_REG_SC		0x01
24#define ABX8XX_REG_MN		0x02
25#define ABX8XX_REG_HR		0x03
26#define ABX8XX_REG_DA		0x04
27#define ABX8XX_REG_MO		0x05
28#define ABX8XX_REG_YR		0x06
29#define ABX8XX_REG_WD		0x07
30
31#define ABX8XX_REG_AHTH		0x08
32#define ABX8XX_REG_ASC		0x09
33#define ABX8XX_REG_AMN		0x0a
34#define ABX8XX_REG_AHR		0x0b
35#define ABX8XX_REG_ADA		0x0c
36#define ABX8XX_REG_AMO		0x0d
37#define ABX8XX_REG_AWD		0x0e
38
39#define ABX8XX_REG_STATUS	0x0f
40#define ABX8XX_STATUS_AF	BIT(2)
41#define ABX8XX_STATUS_BLF	BIT(4)
42#define ABX8XX_STATUS_WDT	BIT(6)
43
44#define ABX8XX_REG_CTRL1	0x10
45#define ABX8XX_CTRL_WRITE	BIT(0)
46#define ABX8XX_CTRL_ARST	BIT(2)
47#define ABX8XX_CTRL_12_24	BIT(6)
48
49#define ABX8XX_REG_CTRL2	0x11
50#define ABX8XX_CTRL2_RSVD	BIT(5)
51
52#define ABX8XX_REG_IRQ		0x12
53#define ABX8XX_IRQ_AIE		BIT(2)
54#define ABX8XX_IRQ_IM_1_4	(0x3 << 5)
55
56#define ABX8XX_REG_CD_TIMER_CTL	0x18
57
58#define ABX8XX_REG_OSC		0x1c
59#define ABX8XX_OSC_FOS		BIT(3)
60#define ABX8XX_OSC_BOS		BIT(4)
61#define ABX8XX_OSC_ACAL_512	BIT(5)
62#define ABX8XX_OSC_ACAL_1024	BIT(6)
63
64#define ABX8XX_OSC_OSEL		BIT(7)
65
66#define ABX8XX_REG_OSS		0x1d
67#define ABX8XX_OSS_OF		BIT(1)
68#define ABX8XX_OSS_OMODE	BIT(4)
69
70#define ABX8XX_REG_WDT		0x1b
71#define ABX8XX_WDT_WDS		BIT(7)
72#define ABX8XX_WDT_BMB_MASK	0x7c
73#define ABX8XX_WDT_BMB_SHIFT	2
74#define ABX8XX_WDT_MAX_TIME	(ABX8XX_WDT_BMB_MASK >> ABX8XX_WDT_BMB_SHIFT)
75#define ABX8XX_WDT_WRB_MASK	0x03
76#define ABX8XX_WDT_WRB_1HZ	0x02
77
78#define ABX8XX_REG_CFG_KEY	0x1f
79#define ABX8XX_CFG_KEY_OSC	0xa1
80#define ABX8XX_CFG_KEY_MISC	0x9d
81
82#define ABX8XX_REG_ID0		0x28
83
84#define ABX8XX_REG_OUT_CTRL	0x30
85#define ABX8XX_OUT_CTRL_EXDS	BIT(4)
86
87#define ABX8XX_REG_TRICKLE	0x20
88#define ABX8XX_TRICKLE_CHARGE_ENABLE	0xa0
89#define ABX8XX_TRICKLE_STANDARD_DIODE	0x8
90#define ABX8XX_TRICKLE_SCHOTTKY_DIODE	0x4
91
92#define ABX8XX_REG_EXTRAM	0x3f
93#define ABX8XX_EXTRAM_XADS	GENMASK(1, 0)
94
95#define ABX8XX_SRAM_BASE	0x40
96#define ABX8XX_SRAM_WIN_SIZE	0x40
97#define ABX8XX_RAM_SIZE		256
98
99#define NVMEM_ADDR_LOWER	GENMASK(5, 0)
100#define NVMEM_ADDR_UPPER	GENMASK(7, 6)
101
102static u8 trickle_resistors[] = {0, 3, 6, 11};
103
104enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
105	AB1801, AB1803, AB1804, AB1805, RV1805, ABX80X};
106
107struct abx80x_cap {
108	u16 pn;
109	bool has_tc;
110	bool has_wdog;
111};
112
113static struct abx80x_cap abx80x_caps[] = {
114	[AB0801] = {.pn = 0x0801},
115	[AB0803] = {.pn = 0x0803},
116	[AB0804] = {.pn = 0x0804, .has_tc = true, .has_wdog = true},
117	[AB0805] = {.pn = 0x0805, .has_tc = true, .has_wdog = true},
118	[AB1801] = {.pn = 0x1801},
119	[AB1803] = {.pn = 0x1803},
120	[AB1804] = {.pn = 0x1804, .has_tc = true, .has_wdog = true},
121	[AB1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
122	[RV1805] = {.pn = 0x1805, .has_tc = true, .has_wdog = true},
123	[ABX80X] = {.pn = 0}
124};
125
126struct abx80x_priv {
127	struct rtc_device *rtc;
128	struct i2c_client *client;
129	struct watchdog_device wdog;
130};
131
132static int abx80x_write_config_key(struct i2c_client *client, u8 key)
133{
134	if (i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY, key) < 0) {
135		dev_err(&client->dev, "Unable to write configuration key\n");
136		return -EIO;
137	}
138
139	return 0;
140}
141
142static int abx80x_is_rc_mode(struct i2c_client *client)
143{
144	int flags = 0;
145
146	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
147	if (flags < 0) {
148		dev_err(&client->dev,
149			"Failed to read autocalibration attribute\n");
150		return flags;
151	}
152
153	return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
154}
155
156static int abx80x_enable_trickle_charger(struct i2c_client *client,
157					 u8 trickle_cfg)
158{
159	int err;
160
161	/*
162	 * Write the configuration key register to enable access to the Trickle
163	 * register
164	 */
165	if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
166		return -EIO;
167
168	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
169					ABX8XX_TRICKLE_CHARGE_ENABLE |
170					trickle_cfg);
171	if (err < 0) {
172		dev_err(&client->dev, "Unable to write trickle register\n");
173		return -EIO;
174	}
175
176	return 0;
177}
178
179static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
180{
181	struct i2c_client *client = to_i2c_client(dev);
182	unsigned char buf[8];
183	int err, flags, rc_mode = 0;
184
185	/* Read the Oscillator Failure only in XT mode */
186	rc_mode = abx80x_is_rc_mode(client);
187	if (rc_mode < 0)
188		return rc_mode;
189
190	if (!rc_mode) {
191		flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
192		if (flags < 0)
193			return flags;
194
195		if (flags & ABX8XX_OSS_OF) {
196			dev_err(dev, "Oscillator failure, data is invalid.\n");
197			return -EINVAL;
198		}
199	}
200
201	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
202					    sizeof(buf), buf);
203	if (err < 0) {
204		dev_err(&client->dev, "Unable to read date\n");
205		return -EIO;
206	}
207
208	tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
209	tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
210	tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
211	tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
212	tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
213	tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
214	tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
215
216	return 0;
217}
218
219static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
220{
221	struct i2c_client *client = to_i2c_client(dev);
222	unsigned char buf[8];
223	int err, flags;
224
225	if (tm->tm_year < 100)
226		return -EINVAL;
227
228	buf[ABX8XX_REG_HTH] = 0;
229	buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
230	buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
231	buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
232	buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
233	buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
234	buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
235	buf[ABX8XX_REG_WD] = tm->tm_wday;
236
237	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
238					     sizeof(buf), buf);
239	if (err < 0) {
240		dev_err(&client->dev, "Unable to write to date registers\n");
241		return -EIO;
242	}
243
244	/* Clear the OF bit of Oscillator Status Register */
245	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
246	if (flags < 0)
247		return flags;
248
249	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSS,
250					flags & ~ABX8XX_OSS_OF);
251	if (err < 0) {
252		dev_err(&client->dev, "Unable to write oscillator status register\n");
253		return err;
254	}
255
256	return 0;
257}
258
259static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
260{
261	struct i2c_client *client = dev_id;
262	struct abx80x_priv *priv = i2c_get_clientdata(client);
263	struct rtc_device *rtc = priv->rtc;
264	int status;
265
266	status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
267	if (status < 0)
268		return IRQ_NONE;
269
270	if (status & ABX8XX_STATUS_AF)
271		rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
272
273	/*
274	 * It is unclear if we'll get an interrupt before the external
275	 * reset kicks in.
276	 */
277	if (status & ABX8XX_STATUS_WDT)
278		dev_alert(&client->dev, "watchdog timeout interrupt.\n");
279
280	i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
281
282	return IRQ_HANDLED;
283}
284
285static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
286{
287	struct i2c_client *client = to_i2c_client(dev);
288	unsigned char buf[7];
289
290	int irq_mask, err;
291
292	if (client->irq <= 0)
293		return -EINVAL;
294
295	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
296					    sizeof(buf), buf);
297	if (err)
298		return err;
299
300	irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
301	if (irq_mask < 0)
302		return irq_mask;
303
304	t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
305	t->time.tm_min = bcd2bin(buf[1] & 0x7F);
306	t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
307	t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
308	t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
309	t->time.tm_wday = buf[5] & 0x7;
310
311	t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
312	t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
313
314	return err;
315}
316
317static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
318{
319	struct i2c_client *client = to_i2c_client(dev);
320	u8 alarm[6];
321	int err;
322
323	if (client->irq <= 0)
324		return -EINVAL;
325
326	alarm[0] = 0x0;
327	alarm[1] = bin2bcd(t->time.tm_sec);
328	alarm[2] = bin2bcd(t->time.tm_min);
329	alarm[3] = bin2bcd(t->time.tm_hour);
330	alarm[4] = bin2bcd(t->time.tm_mday);
331	alarm[5] = bin2bcd(t->time.tm_mon + 1);
332
333	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
334					     sizeof(alarm), alarm);
335	if (err < 0) {
336		dev_err(&client->dev, "Unable to write alarm registers\n");
337		return -EIO;
338	}
339
340	if (t->enabled) {
341		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
342						(ABX8XX_IRQ_IM_1_4 |
343						 ABX8XX_IRQ_AIE));
344		if (err)
345			return err;
346	}
347
348	return 0;
349}
350
351static int abx80x_rtc_set_autocalibration(struct device *dev,
352					  int autocalibration)
353{
354	struct i2c_client *client = to_i2c_client(dev);
355	int retval, flags = 0;
356
357	if ((autocalibration != 0) && (autocalibration != 1024) &&
358	    (autocalibration != 512)) {
359		dev_err(dev, "autocalibration value outside permitted range\n");
360		return -EINVAL;
361	}
362
363	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
364	if (flags < 0)
365		return flags;
366
367	if (autocalibration == 0) {
368		flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
369	} else if (autocalibration == 1024) {
370		/* 1024 autocalibration is 0x10 */
371		flags |= ABX8XX_OSC_ACAL_1024;
372		flags &= ~(ABX8XX_OSC_ACAL_512);
373	} else {
374		/* 512 autocalibration is 0x11 */
375		flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
376	}
377
378	/* Unlock write access to Oscillator Control Register */
379	if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
380		return -EIO;
381
382	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
383
384	return retval;
385}
386
387static int abx80x_rtc_get_autocalibration(struct device *dev)
388{
389	struct i2c_client *client = to_i2c_client(dev);
390	int flags = 0, autocalibration;
391
392	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
393	if (flags < 0)
394		return flags;
395
396	if (flags & ABX8XX_OSC_ACAL_512)
397		autocalibration = 512;
398	else if (flags & ABX8XX_OSC_ACAL_1024)
399		autocalibration = 1024;
400	else
401		autocalibration = 0;
402
403	return autocalibration;
404}
405
406static ssize_t autocalibration_store(struct device *dev,
407				     struct device_attribute *attr,
408				     const char *buf, size_t count)
409{
410	int retval;
411	unsigned long autocalibration = 0;
412
413	retval = kstrtoul(buf, 10, &autocalibration);
414	if (retval < 0) {
415		dev_err(dev, "Failed to store RTC autocalibration attribute\n");
416		return -EINVAL;
417	}
418
419	retval = abx80x_rtc_set_autocalibration(dev->parent, autocalibration);
420
421	return retval ? retval : count;
422}
423
424static ssize_t autocalibration_show(struct device *dev,
425				    struct device_attribute *attr, char *buf)
426{
427	int autocalibration = 0;
428
429	autocalibration = abx80x_rtc_get_autocalibration(dev->parent);
430	if (autocalibration < 0) {
431		dev_err(dev, "Failed to read RTC autocalibration\n");
432		sprintf(buf, "0\n");
433		return autocalibration;
434	}
435
436	return sprintf(buf, "%d\n", autocalibration);
437}
438
439static DEVICE_ATTR_RW(autocalibration);
440
441static ssize_t oscillator_store(struct device *dev,
442				struct device_attribute *attr,
443				const char *buf, size_t count)
444{
445	struct i2c_client *client = to_i2c_client(dev->parent);
446	int retval, flags, rc_mode = 0;
447
448	if (strncmp(buf, "rc", 2) == 0) {
449		rc_mode = 1;
450	} else if (strncmp(buf, "xtal", 4) == 0) {
451		rc_mode = 0;
452	} else {
453		dev_err(dev, "Oscillator selection value outside permitted ones\n");
454		return -EINVAL;
455	}
456
457	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
458	if (flags < 0)
459		return flags;
460
461	if (rc_mode == 0)
462		flags &= ~(ABX8XX_OSC_OSEL);
463	else
464		flags |= (ABX8XX_OSC_OSEL);
465
466	/* Unlock write access on Oscillator Control register */
467	if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_OSC) < 0)
468		return -EIO;
469
470	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
471	if (retval < 0) {
472		dev_err(dev, "Failed to write Oscillator Control register\n");
473		return retval;
474	}
475
476	return retval ? retval : count;
477}
478
479static ssize_t oscillator_show(struct device *dev,
480			       struct device_attribute *attr, char *buf)
481{
482	int rc_mode = 0;
483	struct i2c_client *client = to_i2c_client(dev->parent);
484
485	rc_mode = abx80x_is_rc_mode(client);
486
487	if (rc_mode < 0) {
488		dev_err(dev, "Failed to read RTC oscillator selection\n");
489		sprintf(buf, "\n");
490		return rc_mode;
491	}
492
493	if (rc_mode)
494		return sprintf(buf, "rc\n");
495	else
496		return sprintf(buf, "xtal\n");
497}
498
499static DEVICE_ATTR_RW(oscillator);
500
501static struct attribute *rtc_calib_attrs[] = {
502	&dev_attr_autocalibration.attr,
503	&dev_attr_oscillator.attr,
504	NULL,
505};
506
507static const struct attribute_group rtc_calib_attr_group = {
508	.attrs		= rtc_calib_attrs,
509};
510
511static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
512{
513	struct i2c_client *client = to_i2c_client(dev);
514	int err;
515
516	if (enabled)
517		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
518						(ABX8XX_IRQ_IM_1_4 |
519						 ABX8XX_IRQ_AIE));
520	else
521		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
522						ABX8XX_IRQ_IM_1_4);
523	return err;
524}
525
526static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
527{
528	struct i2c_client *client = to_i2c_client(dev);
529	int status, tmp;
530
531	switch (cmd) {
532	case RTC_VL_READ:
533		status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
534		if (status < 0)
535			return status;
536
537		tmp = status & ABX8XX_STATUS_BLF ? RTC_VL_BACKUP_LOW : 0;
538
539		return put_user(tmp, (unsigned int __user *)arg);
540
541	case RTC_VL_CLR:
542		status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
543		if (status < 0)
544			return status;
545
546		status &= ~ABX8XX_STATUS_BLF;
547
548		tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
549		if (tmp < 0)
550			return tmp;
551
552		return 0;
553
554	default:
555		return -ENOIOCTLCMD;
556	}
557}
558
559static const struct rtc_class_ops abx80x_rtc_ops = {
560	.read_time	= abx80x_rtc_read_time,
561	.set_time	= abx80x_rtc_set_time,
562	.read_alarm	= abx80x_read_alarm,
563	.set_alarm	= abx80x_set_alarm,
564	.alarm_irq_enable = abx80x_alarm_irq_enable,
565	.ioctl		= abx80x_ioctl,
566};
567
568static int abx80x_dt_trickle_cfg(struct i2c_client *client)
569{
570	struct device_node *np = client->dev.of_node;
571	const char *diode;
572	int trickle_cfg = 0;
573	int i, ret;
574	u32 tmp;
575
576	ret = of_property_read_string(np, "abracon,tc-diode", &diode);
577	if (ret)
578		return ret;
579
580	if (!strcmp(diode, "standard")) {
581		trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
582	} else if (!strcmp(diode, "schottky")) {
583		trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
584	} else {
585		dev_dbg(&client->dev, "Invalid tc-diode value: %s\n", diode);
586		return -EINVAL;
587	}
588
589	ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
590	if (ret)
591		return ret;
592
593	for (i = 0; i < sizeof(trickle_resistors); i++)
594		if (trickle_resistors[i] == tmp)
595			break;
596
597	if (i == sizeof(trickle_resistors)) {
598		dev_dbg(&client->dev, "Invalid tc-resistor value: %u\n", tmp);
599		return -EINVAL;
600	}
601
602	return (trickle_cfg | i);
603}
604
605#ifdef CONFIG_WATCHDOG
606
607static inline u8 timeout_bits(unsigned int timeout)
608{
609	return ((timeout << ABX8XX_WDT_BMB_SHIFT) & ABX8XX_WDT_BMB_MASK) |
610		 ABX8XX_WDT_WRB_1HZ;
611}
612
613static int __abx80x_wdog_set_timeout(struct watchdog_device *wdog,
614				     unsigned int timeout)
615{
616	struct abx80x_priv *priv = watchdog_get_drvdata(wdog);
617	u8 val = ABX8XX_WDT_WDS | timeout_bits(timeout);
618
619	/*
620	 * Writing any timeout to the WDT register resets the watchdog timer.
621	 * Writing 0 disables it.
622	 */
623	return i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_WDT, val);
624}
625
626static int abx80x_wdog_set_timeout(struct watchdog_device *wdog,
627				   unsigned int new_timeout)
628{
629	int err = 0;
630
631	if (watchdog_hw_running(wdog))
632		err = __abx80x_wdog_set_timeout(wdog, new_timeout);
633
634	if (err == 0)
635		wdog->timeout = new_timeout;
636
637	return err;
638}
639
640static int abx80x_wdog_ping(struct watchdog_device *wdog)
641{
642	return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
643}
644
645static int abx80x_wdog_start(struct watchdog_device *wdog)
646{
647	return __abx80x_wdog_set_timeout(wdog, wdog->timeout);
648}
649
650static int abx80x_wdog_stop(struct watchdog_device *wdog)
651{
652	return __abx80x_wdog_set_timeout(wdog, 0);
653}
654
655static const struct watchdog_info abx80x_wdog_info = {
656	.identity = "abx80x watchdog",
657	.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
658};
659
660static const struct watchdog_ops abx80x_wdog_ops = {
661	.owner = THIS_MODULE,
662	.start = abx80x_wdog_start,
663	.stop = abx80x_wdog_stop,
664	.ping = abx80x_wdog_ping,
665	.set_timeout = abx80x_wdog_set_timeout,
666};
667
668static int abx80x_setup_watchdog(struct abx80x_priv *priv)
669{
670	priv->wdog.parent = &priv->client->dev;
671	priv->wdog.ops = &abx80x_wdog_ops;
672	priv->wdog.info = &abx80x_wdog_info;
673	priv->wdog.min_timeout = 1;
674	priv->wdog.max_timeout = ABX8XX_WDT_MAX_TIME;
675	priv->wdog.timeout = ABX8XX_WDT_MAX_TIME;
676
677	watchdog_set_drvdata(&priv->wdog, priv);
678
679	return devm_watchdog_register_device(&priv->client->dev, &priv->wdog);
680}
681#else
682static int abx80x_setup_watchdog(struct abx80x_priv *priv)
683{
684	return 0;
685}
686#endif
687
688static int abx80x_nvmem_xfer(struct abx80x_priv *priv, unsigned int offset,
689			     void *val, size_t bytes, bool write)
690{
691	int ret;
692
693	while (bytes) {
694		u8 extram, reg, len, lower, upper;
695
696		lower = FIELD_GET(NVMEM_ADDR_LOWER, offset);
697		upper = FIELD_GET(NVMEM_ADDR_UPPER, offset);
698		extram = FIELD_PREP(ABX8XX_EXTRAM_XADS, upper);
699		reg = ABX8XX_SRAM_BASE + lower;
700		len = min(lower + bytes, (size_t)ABX8XX_SRAM_WIN_SIZE) - lower;
701		len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
702
703		ret = i2c_smbus_write_byte_data(priv->client, ABX8XX_REG_EXTRAM,
704						extram);
705		if (ret)
706			return ret;
707
708		if (write)
709			ret = i2c_smbus_write_i2c_block_data(priv->client, reg,
710							     len, val);
711		else
712			ret = i2c_smbus_read_i2c_block_data(priv->client, reg,
713							    len, val);
714		if (ret)
715			return ret;
716
717		offset += len;
718		val += len;
719		bytes -= len;
720	}
721
722	return 0;
723}
724
725static int abx80x_nvmem_read(void *priv, unsigned int offset, void *val,
726			     size_t bytes)
727{
728	return abx80x_nvmem_xfer(priv, offset, val, bytes, false);
729}
730
731static int abx80x_nvmem_write(void *priv, unsigned int offset, void *val,
732			      size_t bytes)
733{
734	return abx80x_nvmem_xfer(priv, offset, val, bytes, true);
735}
736
737static int abx80x_setup_nvmem(struct abx80x_priv *priv)
738{
739	struct nvmem_config config = {
740		.type = NVMEM_TYPE_BATTERY_BACKED,
741		.reg_read = abx80x_nvmem_read,
742		.reg_write = abx80x_nvmem_write,
743		.size = ABX8XX_RAM_SIZE,
744		.priv = priv,
745	};
746
747	return devm_rtc_nvmem_register(priv->rtc, &config);
748}
749
750static const struct i2c_device_id abx80x_id[] = {
751	{ "abx80x", ABX80X },
752	{ "ab0801", AB0801 },
753	{ "ab0803", AB0803 },
754	{ "ab0804", AB0804 },
755	{ "ab0805", AB0805 },
756	{ "ab1801", AB1801 },
757	{ "ab1803", AB1803 },
758	{ "ab1804", AB1804 },
759	{ "ab1805", AB1805 },
760	{ "rv1805", RV1805 },
761	{ }
762};
763MODULE_DEVICE_TABLE(i2c, abx80x_id);
764
765static int abx80x_probe(struct i2c_client *client)
766{
767	struct device_node *np = client->dev.of_node;
768	struct abx80x_priv *priv;
769	int i, data, err, trickle_cfg = -EINVAL;
770	char buf[7];
771	const struct i2c_device_id *id = i2c_match_id(abx80x_id, client);
772	unsigned int part = id->driver_data;
773	unsigned int partnumber;
774	unsigned int majrev, minrev;
775	unsigned int lot;
776	unsigned int wafer;
777	unsigned int uid;
778
779	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
780		return -ENODEV;
781
782	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
783					    sizeof(buf), buf);
784	if (err < 0) {
785		dev_err(&client->dev, "Unable to read partnumber\n");
786		return -EIO;
787	}
788
789	partnumber = (buf[0] << 8) | buf[1];
790	majrev = buf[2] >> 3;
791	minrev = buf[2] & 0x7;
792	lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
793	uid = ((buf[4] & 0x7f) << 8) | buf[5];
794	wafer = (buf[6] & 0x7c) >> 2;
795	dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
796		 partnumber, majrev, minrev, lot, wafer, uid);
797
798	data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
799	if (data < 0) {
800		dev_err(&client->dev, "Unable to read control register\n");
801		return -EIO;
802	}
803
804	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
805					((data & ~(ABX8XX_CTRL_12_24 |
806						   ABX8XX_CTRL_ARST)) |
807					 ABX8XX_CTRL_WRITE));
808	if (err < 0) {
809		dev_err(&client->dev, "Unable to write control register\n");
810		return -EIO;
811	}
812
813	/* Configure RV1805 specifics */
814	if (part == RV1805) {
815		/*
816		 * Avoid accidentally entering test mode. This can happen
817		 * on the RV1805 in case the reserved bit 5 in control2
818		 * register is set. RV-1805-C3 datasheet indicates that
819		 * the bit should be cleared in section 11h - Control2.
820		 */
821		data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL2);
822		if (data < 0) {
823			dev_err(&client->dev,
824				"Unable to read control2 register\n");
825			return -EIO;
826		}
827
828		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL2,
829						data & ~ABX8XX_CTRL2_RSVD);
830		if (err < 0) {
831			dev_err(&client->dev,
832				"Unable to write control2 register\n");
833			return -EIO;
834		}
835
836		/*
837		 * Avoid extra power leakage. The RV1805 uses smaller
838		 * 10pin package and the EXTI input is not present.
839		 * Disable it to avoid leakage.
840		 */
841		data = i2c_smbus_read_byte_data(client, ABX8XX_REG_OUT_CTRL);
842		if (data < 0) {
843			dev_err(&client->dev,
844				"Unable to read output control register\n");
845			return -EIO;
846		}
847
848		/*
849		 * Write the configuration key register to enable access to
850		 * the config2 register
851		 */
852		if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
853			return -EIO;
854
855		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_OUT_CTRL,
856						data | ABX8XX_OUT_CTRL_EXDS);
857		if (err < 0) {
858			dev_err(&client->dev,
859				"Unable to write output control register\n");
860			return -EIO;
861		}
862	}
863
864	/* part autodetection */
865	if (part == ABX80X) {
866		for (i = 0; abx80x_caps[i].pn; i++)
867			if (partnumber == abx80x_caps[i].pn)
868				break;
869		if (abx80x_caps[i].pn == 0) {
870			dev_err(&client->dev, "Unknown part: %04x\n",
871				partnumber);
872			return -EINVAL;
873		}
874		part = i;
875	}
876
877	if (partnumber != abx80x_caps[part].pn) {
878		dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
879			partnumber, abx80x_caps[part].pn);
880		return -EINVAL;
881	}
882
883	if (np && abx80x_caps[part].has_tc)
884		trickle_cfg = abx80x_dt_trickle_cfg(client);
885
886	if (trickle_cfg > 0) {
887		dev_info(&client->dev, "Enabling trickle charger: %02x\n",
888			 trickle_cfg);
889		abx80x_enable_trickle_charger(client, trickle_cfg);
890	}
891
892	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
893					BIT(2));
894	if (err)
895		return err;
896
897	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
898	if (priv == NULL)
899		return -ENOMEM;
900
901	priv->rtc = devm_rtc_allocate_device(&client->dev);
902	if (IS_ERR(priv->rtc))
903		return PTR_ERR(priv->rtc);
904
905	priv->rtc->ops = &abx80x_rtc_ops;
906	priv->client = client;
907
908	i2c_set_clientdata(client, priv);
909
910	if (abx80x_caps[part].has_wdog) {
911		err = abx80x_setup_watchdog(priv);
912		if (err)
913			return err;
914	}
915
916	err = abx80x_setup_nvmem(priv);
917	if (err)
918		return err;
919
920	if (client->irq > 0) {
921		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
922		err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
923						abx80x_handle_irq,
924						IRQF_SHARED | IRQF_ONESHOT,
925						"abx8xx",
926						client);
927		if (err) {
928			dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
929			client->irq = 0;
930		}
931	}
932
933	err = rtc_add_group(priv->rtc, &rtc_calib_attr_group);
934	if (err) {
935		dev_err(&client->dev, "Failed to create sysfs group: %d\n",
936			err);
937		return err;
938	}
939
940	return devm_rtc_register_device(priv->rtc);
941}
942
943#ifdef CONFIG_OF
944static const struct of_device_id abx80x_of_match[] = {
945	{
946		.compatible = "abracon,abx80x",
947		.data = (void *)ABX80X
948	},
949	{
950		.compatible = "abracon,ab0801",
951		.data = (void *)AB0801
952	},
953	{
954		.compatible = "abracon,ab0803",
955		.data = (void *)AB0803
956	},
957	{
958		.compatible = "abracon,ab0804",
959		.data = (void *)AB0804
960	},
961	{
962		.compatible = "abracon,ab0805",
963		.data = (void *)AB0805
964	},
965	{
966		.compatible = "abracon,ab1801",
967		.data = (void *)AB1801
968	},
969	{
970		.compatible = "abracon,ab1803",
971		.data = (void *)AB1803
972	},
973	{
974		.compatible = "abracon,ab1804",
975		.data = (void *)AB1804
976	},
977	{
978		.compatible = "abracon,ab1805",
979		.data = (void *)AB1805
980	},
981	{
982		.compatible = "microcrystal,rv1805",
983		.data = (void *)RV1805
984	},
985	{ }
986};
987MODULE_DEVICE_TABLE(of, abx80x_of_match);
988#endif
989
990static struct i2c_driver abx80x_driver = {
991	.driver		= {
992		.name	= "rtc-abx80x",
993		.of_match_table = of_match_ptr(abx80x_of_match),
994	},
995	.probe		= abx80x_probe,
996	.id_table	= abx80x_id,
997};
998
999module_i2c_driver(abx80x_driver);
1000
1001MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
1002MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1003MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
1004MODULE_LICENSE("GPL v2");
1005