1 /*
2  * rtc-isl12057 - Driver for Intersil ISL12057 I2C Real Time Clock
3  *
4  * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
5  *
6  * This work is largely based on Intersil ISL1208 driver developed by
7  * Hebert Valerio Riedel <hvr@gnu.org>.
8  *
9  * Detailed datasheet on which this development is based is available here:
10  *
11  *  http://natisbad.org/NAS2/refs/ISL12057.pdf
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  */
23 
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/rtc.h>
27 #include <linux/i2c.h>
28 #include <linux/bcd.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31 #include <linux/regmap.h>
32 
33 #define DRV_NAME "rtc-isl12057"
34 
35 /* RTC section */
36 #define ISL12057_REG_RTC_SC	0x00	/* Seconds */
37 #define ISL12057_REG_RTC_MN	0x01	/* Minutes */
38 #define ISL12057_REG_RTC_HR	0x02	/* Hours */
39 #define ISL12057_REG_RTC_HR_PM	BIT(5)	/* AM/PM bit in 12h format */
40 #define ISL12057_REG_RTC_HR_MIL BIT(6)	/* 24h/12h format */
41 #define ISL12057_REG_RTC_DW	0x03	/* Day of the Week */
42 #define ISL12057_REG_RTC_DT	0x04	/* Date */
43 #define ISL12057_REG_RTC_MO	0x05	/* Month */
44 #define ISL12057_REG_RTC_MO_CEN	BIT(7)	/* Century bit */
45 #define ISL12057_REG_RTC_YR	0x06	/* Year */
46 #define ISL12057_RTC_SEC_LEN	7
47 
48 /* Alarm 1 section */
49 #define ISL12057_REG_A1_SC	0x07	/* Alarm 1 Seconds */
50 #define ISL12057_REG_A1_MN	0x08	/* Alarm 1 Minutes */
51 #define ISL12057_REG_A1_HR	0x09	/* Alarm 1 Hours */
52 #define ISL12057_REG_A1_HR_PM	BIT(5)	/* AM/PM bit in 12h format */
53 #define ISL12057_REG_A1_HR_MIL	BIT(6)	/* 24h/12h format */
54 #define ISL12057_REG_A1_DWDT	0x0A	/* Alarm 1 Date / Day of the week */
55 #define ISL12057_REG_A1_DWDT_B	BIT(6)	/* DW / DT selection bit */
56 #define ISL12057_A1_SEC_LEN	4
57 
58 /* Alarm 2 section */
59 #define ISL12057_REG_A2_MN	0x0B	/* Alarm 2 Minutes */
60 #define ISL12057_REG_A2_HR	0x0C	/* Alarm 2 Hours */
61 #define ISL12057_REG_A2_DWDT	0x0D	/* Alarm 2 Date / Day of the week */
62 #define ISL12057_A2_SEC_LEN	3
63 
64 /* Control/Status registers */
65 #define ISL12057_REG_INT	0x0E
66 #define ISL12057_REG_INT_A1IE	BIT(0)	/* Alarm 1 interrupt enable bit */
67 #define ISL12057_REG_INT_A2IE	BIT(1)	/* Alarm 2 interrupt enable bit */
68 #define ISL12057_REG_INT_INTCN	BIT(2)	/* Interrupt control enable bit */
69 #define ISL12057_REG_INT_RS1	BIT(3)	/* Freq out control bit 1 */
70 #define ISL12057_REG_INT_RS2	BIT(4)	/* Freq out control bit 2 */
71 #define ISL12057_REG_INT_EOSC	BIT(7)	/* Oscillator enable bit */
72 
73 #define ISL12057_REG_SR		0x0F
74 #define ISL12057_REG_SR_A1F	BIT(0)	/* Alarm 1 interrupt bit */
75 #define ISL12057_REG_SR_A2F	BIT(1)	/* Alarm 2 interrupt bit */
76 #define ISL12057_REG_SR_OSF	BIT(7)	/* Oscillator failure bit */
77 
78 /* Register memory map length */
79 #define ISL12057_MEM_MAP_LEN	0x10
80 
81 struct isl12057_rtc_data {
82 	struct rtc_device *rtc;
83 	struct regmap *regmap;
84 	struct mutex lock;
85 	int irq;
86 };
87 
isl12057_rtc_regs_to_tm(struct rtc_time * tm,u8 * regs)88 static void isl12057_rtc_regs_to_tm(struct rtc_time *tm, u8 *regs)
89 {
90 	tm->tm_sec = bcd2bin(regs[ISL12057_REG_RTC_SC]);
91 	tm->tm_min = bcd2bin(regs[ISL12057_REG_RTC_MN]);
92 
93 	if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_MIL) { /* AM/PM */
94 		tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x1f);
95 		if (regs[ISL12057_REG_RTC_HR] & ISL12057_REG_RTC_HR_PM)
96 			tm->tm_hour += 12;
97 	} else {					    /* 24 hour mode */
98 		tm->tm_hour = bcd2bin(regs[ISL12057_REG_RTC_HR] & 0x3f);
99 	}
100 
101 	tm->tm_mday = bcd2bin(regs[ISL12057_REG_RTC_DT]);
102 	tm->tm_wday = bcd2bin(regs[ISL12057_REG_RTC_DW]) - 1; /* starts at 1 */
103 	tm->tm_mon  = bcd2bin(regs[ISL12057_REG_RTC_MO] & 0x1f) - 1; /* ditto */
104 	tm->tm_year = bcd2bin(regs[ISL12057_REG_RTC_YR]) + 100;
105 
106 	/* Check if years register has overflown from 99 to 00 */
107 	if (regs[ISL12057_REG_RTC_MO] & ISL12057_REG_RTC_MO_CEN)
108 		tm->tm_year += 100;
109 }
110 
isl12057_rtc_tm_to_regs(u8 * regs,struct rtc_time * tm)111 static int isl12057_rtc_tm_to_regs(u8 *regs, struct rtc_time *tm)
112 {
113 	u8 century_bit;
114 
115 	/*
116 	 * The clock has an 8 bit wide bcd-coded register for the year.
117 	 * It also has a century bit encoded in MO flag which provides
118 	 * information about overflow of year register from 99 to 00.
119 	 * tm_year is an offset from 1900 and we are interested in the
120 	 * 2000-2199 range, so any value less than 100 or larger than
121 	 * 299 is invalid.
122 	 */
123 	if (tm->tm_year < 100 || tm->tm_year > 299)
124 		return -EINVAL;
125 
126 	century_bit = (tm->tm_year > 199) ? ISL12057_REG_RTC_MO_CEN : 0;
127 
128 	regs[ISL12057_REG_RTC_SC] = bin2bcd(tm->tm_sec);
129 	regs[ISL12057_REG_RTC_MN] = bin2bcd(tm->tm_min);
130 	regs[ISL12057_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */
131 	regs[ISL12057_REG_RTC_DT] = bin2bcd(tm->tm_mday);
132 	regs[ISL12057_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1) | century_bit;
133 	regs[ISL12057_REG_RTC_YR] = bin2bcd(tm->tm_year % 100);
134 	regs[ISL12057_REG_RTC_DW] = bin2bcd(tm->tm_wday + 1);
135 
136 	return 0;
137 }
138 
139 /*
140  * Try and match register bits w/ fixed null values to see whether we
141  * are dealing with an ISL12057. Note: this function is called early
142  * during init and hence does need mutex protection.
143  */
isl12057_i2c_validate_chip(struct regmap * regmap)144 static int isl12057_i2c_validate_chip(struct regmap *regmap)
145 {
146 	u8 regs[ISL12057_MEM_MAP_LEN];
147 	static const u8 mask[ISL12057_MEM_MAP_LEN] = { 0x80, 0x80, 0x80, 0xf8,
148 						       0xc0, 0x60, 0x00, 0x00,
149 						       0x00, 0x00, 0x00, 0x00,
150 						       0x00, 0x00, 0x60, 0x7c };
151 	int ret, i;
152 
153 	ret = regmap_bulk_read(regmap, 0, regs, ISL12057_MEM_MAP_LEN);
154 	if (ret)
155 		return ret;
156 
157 	for (i = 0; i < ISL12057_MEM_MAP_LEN; ++i) {
158 		if (regs[i] & mask[i])	/* check if bits are cleared */
159 			return -ENODEV;
160 	}
161 
162 	return 0;
163 }
164 
_isl12057_rtc_clear_alarm(struct device * dev)165 static int _isl12057_rtc_clear_alarm(struct device *dev)
166 {
167 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
168 	int ret;
169 
170 	ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
171 				 ISL12057_REG_SR_A1F, 0);
172 	if (ret)
173 		dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret);
174 
175 	return ret;
176 }
177 
_isl12057_rtc_update_alarm(struct device * dev,int enable)178 static int _isl12057_rtc_update_alarm(struct device *dev, int enable)
179 {
180 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
181 	int ret;
182 
183 	ret = regmap_update_bits(data->regmap, ISL12057_REG_INT,
184 				 ISL12057_REG_INT_A1IE,
185 				 enable ? ISL12057_REG_INT_A1IE : 0);
186 	if (ret)
187 		dev_err(dev, "%s: changing alarm interrupt flag failed (%d)\n",
188 			__func__, ret);
189 
190 	return ret;
191 }
192 
193 /*
194  * Note: as we only read from device and do not perform any update, there is
195  * no need for an equivalent function which would try and get driver's main
196  * lock. Here, it is safe for everyone if we just use regmap internal lock
197  * on the device when reading.
198  */
_isl12057_rtc_read_time(struct device * dev,struct rtc_time * tm)199 static int _isl12057_rtc_read_time(struct device *dev, struct rtc_time *tm)
200 {
201 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
202 	u8 regs[ISL12057_RTC_SEC_LEN];
203 	unsigned int sr;
204 	int ret;
205 
206 	ret = regmap_read(data->regmap, ISL12057_REG_SR, &sr);
207 	if (ret) {
208 		dev_err(dev, "%s: unable to read oscillator status flag (%d)\n",
209 			__func__, ret);
210 		goto out;
211 	} else {
212 		if (sr & ISL12057_REG_SR_OSF) {
213 			ret = -ENODATA;
214 			goto out;
215 		}
216 	}
217 
218 	ret = regmap_bulk_read(data->regmap, ISL12057_REG_RTC_SC, regs,
219 			       ISL12057_RTC_SEC_LEN);
220 	if (ret)
221 		dev_err(dev, "%s: unable to read RTC time section (%d)\n",
222 			__func__, ret);
223 
224 out:
225 	if (ret)
226 		return ret;
227 
228 	isl12057_rtc_regs_to_tm(tm, regs);
229 
230 	return rtc_valid_tm(tm);
231 }
232 
isl12057_rtc_update_alarm(struct device * dev,int enable)233 static int isl12057_rtc_update_alarm(struct device *dev, int enable)
234 {
235 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
236 	int ret;
237 
238 	mutex_lock(&data->lock);
239 	ret = _isl12057_rtc_update_alarm(dev, enable);
240 	mutex_unlock(&data->lock);
241 
242 	return ret;
243 }
244 
isl12057_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)245 static int isl12057_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
246 {
247 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
248 	struct rtc_time rtc_tm, *alarm_tm = &alarm->time;
249 	unsigned long rtc_secs, alarm_secs;
250 	u8 regs[ISL12057_A1_SEC_LEN];
251 	unsigned int ir;
252 	int ret;
253 
254 	mutex_lock(&data->lock);
255 	ret = regmap_bulk_read(data->regmap, ISL12057_REG_A1_SC, regs,
256 			       ISL12057_A1_SEC_LEN);
257 	if (ret) {
258 		dev_err(dev, "%s: reading alarm section failed (%d)\n",
259 			__func__, ret);
260 		goto err_unlock;
261 	}
262 
263 	alarm_tm->tm_sec  = bcd2bin(regs[0] & 0x7f);
264 	alarm_tm->tm_min  = bcd2bin(regs[1] & 0x7f);
265 	alarm_tm->tm_hour = bcd2bin(regs[2] & 0x3f);
266 	alarm_tm->tm_mday = bcd2bin(regs[3] & 0x3f);
267 	alarm_tm->tm_wday = -1;
268 
269 	/*
270 	 * The alarm section does not store year/month. We use the ones in rtc
271 	 * section as a basis and increment month and then year if needed to get
272 	 * alarm after current time.
273 	 */
274 	ret = _isl12057_rtc_read_time(dev, &rtc_tm);
275 	if (ret)
276 		goto err_unlock;
277 
278 	alarm_tm->tm_year = rtc_tm.tm_year;
279 	alarm_tm->tm_mon = rtc_tm.tm_mon;
280 
281 	ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
282 	if (ret)
283 		goto err_unlock;
284 
285 	ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
286 	if (ret)
287 		goto err_unlock;
288 
289 	if (alarm_secs < rtc_secs) {
290 		if (alarm_tm->tm_mon == 11) {
291 			alarm_tm->tm_mon = 0;
292 			alarm_tm->tm_year += 1;
293 		} else {
294 			alarm_tm->tm_mon += 1;
295 		}
296 	}
297 
298 	ret = regmap_read(data->regmap, ISL12057_REG_INT, &ir);
299 	if (ret) {
300 		dev_err(dev, "%s: reading alarm interrupt flag failed (%d)\n",
301 			__func__, ret);
302 		goto err_unlock;
303 	}
304 
305 	alarm->enabled = !!(ir & ISL12057_REG_INT_A1IE);
306 
307 err_unlock:
308 	mutex_unlock(&data->lock);
309 
310 	return ret;
311 }
312 
isl12057_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)313 static int isl12057_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
314 {
315 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
316 	struct rtc_time *alarm_tm = &alarm->time;
317 	unsigned long rtc_secs, alarm_secs;
318 	u8 regs[ISL12057_A1_SEC_LEN];
319 	struct rtc_time rtc_tm;
320 	int ret, enable = 1;
321 
322 	mutex_lock(&data->lock);
323 	ret = _isl12057_rtc_read_time(dev, &rtc_tm);
324 	if (ret)
325 		goto err_unlock;
326 
327 	ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
328 	if (ret)
329 		goto err_unlock;
330 
331 	ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
332 	if (ret)
333 		goto err_unlock;
334 
335 	/* If alarm time is before current time, disable the alarm */
336 	if (!alarm->enabled || alarm_secs <= rtc_secs) {
337 		enable = 0;
338 	} else {
339 		/*
340 		 * Chip only support alarms up to one month in the future. Let's
341 		 * return an error if we get something after that limit.
342 		 * Comparison is done by incrementing rtc_tm month field by one
343 		 * and checking alarm value is still below.
344 		 */
345 		if (rtc_tm.tm_mon == 11) { /* handle year wrapping */
346 			rtc_tm.tm_mon = 0;
347 			rtc_tm.tm_year += 1;
348 		} else {
349 			rtc_tm.tm_mon += 1;
350 		}
351 
352 		ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
353 		if (ret)
354 			goto err_unlock;
355 
356 		if (alarm_secs > rtc_secs) {
357 			dev_err(dev, "%s: max for alarm is one month (%d)\n",
358 				__func__, ret);
359 			ret = -EINVAL;
360 			goto err_unlock;
361 		}
362 	}
363 
364 	/* Disable the alarm before modifying it */
365 	ret = _isl12057_rtc_update_alarm(dev, 0);
366 	if (ret < 0) {
367 		dev_err(dev, "%s: unable to disable the alarm (%d)\n",
368 			__func__, ret);
369 		goto err_unlock;
370 	}
371 
372 	/* Program alarm registers */
373 	regs[0] = bin2bcd(alarm_tm->tm_sec) & 0x7f;
374 	regs[1] = bin2bcd(alarm_tm->tm_min) & 0x7f;
375 	regs[2] = bin2bcd(alarm_tm->tm_hour) & 0x3f;
376 	regs[3] = bin2bcd(alarm_tm->tm_mday) & 0x3f;
377 
378 	ret = regmap_bulk_write(data->regmap, ISL12057_REG_A1_SC, regs,
379 				ISL12057_A1_SEC_LEN);
380 	if (ret < 0) {
381 		dev_err(dev, "%s: writing alarm section failed (%d)\n",
382 			__func__, ret);
383 		goto err_unlock;
384 	}
385 
386 	/* Enable or disable alarm */
387 	ret = _isl12057_rtc_update_alarm(dev, enable);
388 
389 err_unlock:
390 	mutex_unlock(&data->lock);
391 
392 	return ret;
393 }
394 
isl12057_rtc_set_time(struct device * dev,struct rtc_time * tm)395 static int isl12057_rtc_set_time(struct device *dev, struct rtc_time *tm)
396 {
397 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
398 	u8 regs[ISL12057_RTC_SEC_LEN];
399 	int ret;
400 
401 	ret = isl12057_rtc_tm_to_regs(regs, tm);
402 	if (ret)
403 		return ret;
404 
405 	mutex_lock(&data->lock);
406 	ret = regmap_bulk_write(data->regmap, ISL12057_REG_RTC_SC, regs,
407 				ISL12057_RTC_SEC_LEN);
408 	if (ret) {
409 		dev_err(dev, "%s: unable to write RTC time section (%d)\n",
410 			__func__, ret);
411 		goto out;
412 	}
413 
414 	/*
415 	 * Now that RTC time has been updated, let's clear oscillator
416 	 * failure flag, if needed.
417 	 */
418 	ret = regmap_update_bits(data->regmap, ISL12057_REG_SR,
419 				 ISL12057_REG_SR_OSF, 0);
420 	if (ret < 0)
421 		dev_err(dev, "%s: unable to clear osc. failure bit (%d)\n",
422 			__func__, ret);
423 
424 out:
425 	mutex_unlock(&data->lock);
426 
427 	return ret;
428 }
429 
430 /*
431  * Check current RTC status and enable/disable what needs to be. Return 0 if
432  * everything went ok and a negative value upon error. Note: this function
433  * is called early during init and hence does need mutex protection.
434  */
isl12057_check_rtc_status(struct device * dev,struct regmap * regmap)435 static int isl12057_check_rtc_status(struct device *dev, struct regmap *regmap)
436 {
437 	int ret;
438 
439 	/* Enable oscillator if not already running */
440 	ret = regmap_update_bits(regmap, ISL12057_REG_INT,
441 				 ISL12057_REG_INT_EOSC, 0);
442 	if (ret < 0) {
443 		dev_err(dev, "%s: unable to enable oscillator (%d)\n",
444 			__func__, ret);
445 		return ret;
446 	}
447 
448 	/* Clear alarm bit if needed */
449 	ret = regmap_update_bits(regmap, ISL12057_REG_SR,
450 				 ISL12057_REG_SR_A1F, 0);
451 	if (ret < 0) {
452 		dev_err(dev, "%s: unable to clear alarm bit (%d)\n",
453 			__func__, ret);
454 		return ret;
455 	}
456 
457 	return 0;
458 }
459 
460 #ifdef CONFIG_OF
461 /*
462  * One would expect the device to be marked as a wakeup source only
463  * when an IRQ pin of the RTC is routed to an interrupt line of the
464  * CPU. In practice, such an IRQ pin can be connected to a PMIC and
465  * this allows the device to be powered up when RTC alarm rings. This
466  * is for instance the case on ReadyNAS 102, 104 and 2120. On those
467  * devices with no IRQ driectly connected to the SoC, the RTC chip
468  * can be forced as a wakeup source by stating that explicitly in
469  * the device's .dts file using the "wakeup-source" boolean property.
470  * This will guarantee 'wakealarm' sysfs entry is available on the device.
471  *
472  * The function below returns 1, i.e. the capability of the chip to
473  * wakeup the device, based on IRQ availability or if the boolean
474  * property has been set in the .dts file. Otherwise, it returns 0.
475  */
476 
isl12057_can_wakeup_machine(struct device * dev)477 static bool isl12057_can_wakeup_machine(struct device *dev)
478 {
479 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
480 
481 	return data->irq || of_property_read_bool(dev->of_node, "wakeup-source")
482 		|| of_property_read_bool(dev->of_node, /* legacy */
483 					 "isil,irq2-can-wakeup-machine");
484 }
485 #else
isl12057_can_wakeup_machine(struct device * dev)486 static bool isl12057_can_wakeup_machine(struct device *dev)
487 {
488 	struct isl12057_rtc_data *data = dev_get_drvdata(dev);
489 
490 	return !!data->irq;
491 }
492 #endif
493 
isl12057_rtc_alarm_irq_enable(struct device * dev,unsigned int enable)494 static int isl12057_rtc_alarm_irq_enable(struct device *dev,
495 					 unsigned int enable)
496 {
497 	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
498 	int ret = -ENOTTY;
499 
500 	if (rtc_data->irq)
501 		ret = isl12057_rtc_update_alarm(dev, enable);
502 
503 	return ret;
504 }
505 
isl12057_rtc_interrupt(int irq,void * data)506 static irqreturn_t isl12057_rtc_interrupt(int irq, void *data)
507 {
508 	struct i2c_client *client = data;
509 	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
510 	struct rtc_device *rtc = rtc_data->rtc;
511 	int ret, handled = IRQ_NONE;
512 	unsigned int sr;
513 
514 	ret = regmap_read(rtc_data->regmap, ISL12057_REG_SR, &sr);
515 	if (!ret && (sr & ISL12057_REG_SR_A1F)) {
516 		dev_dbg(&client->dev, "RTC alarm!\n");
517 
518 		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
519 
520 		/* Acknowledge and disable the alarm */
521 		_isl12057_rtc_clear_alarm(&client->dev);
522 		_isl12057_rtc_update_alarm(&client->dev, 0);
523 
524 		handled = IRQ_HANDLED;
525 	}
526 
527 	return handled;
528 }
529 
530 static const struct rtc_class_ops rtc_ops = {
531 	.read_time = _isl12057_rtc_read_time,
532 	.set_time = isl12057_rtc_set_time,
533 	.read_alarm = isl12057_rtc_read_alarm,
534 	.set_alarm = isl12057_rtc_set_alarm,
535 	.alarm_irq_enable = isl12057_rtc_alarm_irq_enable,
536 };
537 
538 static const struct regmap_config isl12057_rtc_regmap_config = {
539 	.reg_bits = 8,
540 	.val_bits = 8,
541 };
542 
isl12057_probe(struct i2c_client * client,const struct i2c_device_id * id)543 static int isl12057_probe(struct i2c_client *client,
544 			  const struct i2c_device_id *id)
545 {
546 	struct device *dev = &client->dev;
547 	struct isl12057_rtc_data *data;
548 	struct regmap *regmap;
549 	int ret;
550 
551 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
552 				     I2C_FUNC_SMBUS_BYTE_DATA |
553 				     I2C_FUNC_SMBUS_I2C_BLOCK))
554 		return -ENODEV;
555 
556 	regmap = devm_regmap_init_i2c(client, &isl12057_rtc_regmap_config);
557 	if (IS_ERR(regmap)) {
558 		ret = PTR_ERR(regmap);
559 		dev_err(dev, "%s: regmap allocation failed (%d)\n",
560 			__func__, ret);
561 		return ret;
562 	}
563 
564 	ret = isl12057_i2c_validate_chip(regmap);
565 	if (ret)
566 		return ret;
567 
568 	ret = isl12057_check_rtc_status(dev, regmap);
569 	if (ret)
570 		return ret;
571 
572 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
573 	if (!data)
574 		return -ENOMEM;
575 
576 	mutex_init(&data->lock);
577 	data->regmap = regmap;
578 	dev_set_drvdata(dev, data);
579 
580 	if (client->irq > 0) {
581 		ret = devm_request_threaded_irq(dev, client->irq, NULL,
582 						isl12057_rtc_interrupt,
583 						IRQF_SHARED|IRQF_ONESHOT,
584 						DRV_NAME, client);
585 		if (!ret)
586 			data->irq = client->irq;
587 		else
588 			dev_err(dev, "%s: irq %d unavailable (%d)\n", __func__,
589 				client->irq, ret);
590 	}
591 
592 	if (isl12057_can_wakeup_machine(dev))
593 		device_init_wakeup(dev, true);
594 
595 	data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops,
596 					     THIS_MODULE);
597 	ret = PTR_ERR_OR_ZERO(data->rtc);
598 	if (ret) {
599 		dev_err(dev, "%s: unable to register RTC device (%d)\n",
600 			__func__, ret);
601 		goto err;
602 	}
603 
604 	/* We cannot support UIE mode if we do not have an IRQ line */
605 	if (!data->irq)
606 		data->rtc->uie_unsupported = 1;
607 
608 err:
609 	return ret;
610 }
611 
isl12057_remove(struct i2c_client * client)612 static int isl12057_remove(struct i2c_client *client)
613 {
614 	if (isl12057_can_wakeup_machine(&client->dev))
615 		device_init_wakeup(&client->dev, false);
616 
617 	return 0;
618 }
619 
620 #ifdef CONFIG_PM_SLEEP
isl12057_rtc_suspend(struct device * dev)621 static int isl12057_rtc_suspend(struct device *dev)
622 {
623 	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
624 
625 	if (rtc_data->irq && device_may_wakeup(dev))
626 		return enable_irq_wake(rtc_data->irq);
627 
628 	return 0;
629 }
630 
isl12057_rtc_resume(struct device * dev)631 static int isl12057_rtc_resume(struct device *dev)
632 {
633 	struct isl12057_rtc_data *rtc_data = dev_get_drvdata(dev);
634 
635 	if (rtc_data->irq && device_may_wakeup(dev))
636 		return disable_irq_wake(rtc_data->irq);
637 
638 	return 0;
639 }
640 #endif
641 
642 static SIMPLE_DEV_PM_OPS(isl12057_rtc_pm_ops, isl12057_rtc_suspend,
643 			 isl12057_rtc_resume);
644 
645 #ifdef CONFIG_OF
646 static const struct of_device_id isl12057_dt_match[] = {
647 	{ .compatible = "isl,isl12057" }, /* for backward compat., don't use */
648 	{ .compatible = "isil,isl12057" },
649 	{ },
650 };
651 MODULE_DEVICE_TABLE(of, isl12057_dt_match);
652 #endif
653 
654 static const struct i2c_device_id isl12057_id[] = {
655 	{ "isl12057", 0 },
656 	{ }
657 };
658 MODULE_DEVICE_TABLE(i2c, isl12057_id);
659 
660 static struct i2c_driver isl12057_driver = {
661 	.driver = {
662 		.name = DRV_NAME,
663 		.pm = &isl12057_rtc_pm_ops,
664 		.of_match_table = of_match_ptr(isl12057_dt_match),
665 	},
666 	.probe	  = isl12057_probe,
667 	.remove	  = isl12057_remove,
668 	.id_table = isl12057_id,
669 };
670 module_i2c_driver(isl12057_driver);
671 
672 MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
673 MODULE_DESCRIPTION("Intersil ISL12057 RTC driver");
674 MODULE_LICENSE("GPL");
675