2 * RTC driver for Maxim MAX77686 and MAX77802
4 * Copyright (C) 2012 Samsung Electronics Co.Ltd
6 * based on rtc-max8997.c
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 #include <linux/slab.h>
18 #include <linux/rtc.h>
19 #include <linux/delay.h>
20 #include <linux/mutex.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/mfd/max77686-private.h>
24 #include <linux/irqdomain.h>
25 #include <linux/regmap.h>
27 /* RTC Control Register */
28 #define BCD_EN_SHIFT 0
29 #define BCD_EN_MASK (1 << BCD_EN_SHIFT)
30 #define MODEL24_SHIFT 1
31 #define MODEL24_MASK (1 << MODEL24_SHIFT)
32 /* RTC Update Register1 */
33 #define RTC_UDR_SHIFT 0
34 #define RTC_UDR_MASK (1 << RTC_UDR_SHIFT)
35 #define RTC_RBUDR_SHIFT 4
36 #define RTC_RBUDR_MASK (1 << RTC_RBUDR_SHIFT)
37 /* RTC Hour register */
38 #define HOUR_PM_SHIFT 6
39 #define HOUR_PM_MASK (1 << HOUR_PM_SHIFT)
40 /* RTC Alarm Enable */
41 #define ALARM_ENABLE_SHIFT 7
42 #define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)
44 #define REG_RTC_NONE 0xdeadbeef
47 * MAX77802 has separate register (RTCAE1) for alarm enable instead
48 * using 1 bit from registers RTC{SEC,MIN,HOUR,DAY,MONTH,YEAR,DATE}
49 * as in done in MAX77686.
51 #define MAX77802_ALARM_ENABLE_VALUE 0x77
64 struct max77686_rtc_driver_data {
65 /* Minimum usecs needed for a RTC update */
67 /* Mask used to read RTC registers value */
69 /* Registers offset to I2C addresses map */
70 const unsigned int *map;
71 /* Has a separate alarm enable register? */
72 bool alarm_enable_reg;
73 /* Has a separate I2C regmap for the RTC? */
74 bool separate_i2c_addr;
77 struct max77686_rtc_info {
79 struct max77686_dev *max77686;
80 struct i2c_client *rtc;
81 struct rtc_device *rtc_dev;
84 struct regmap *regmap;
86 const struct max77686_rtc_driver_data *drv_data;
92 enum MAX77686_RTC_OP {
97 /* These are not registers but just offsets that are mapped to addresses */
98 enum max77686_rtc_reg_offset {
128 /* Maps RTC registers offset to the MAX77686 register addresses */
129 static const unsigned int max77686_map[REG_RTC_END] = {
130 [REG_RTC_CONTROLM] = MAX77686_RTC_CONTROLM,
131 [REG_RTC_CONTROL] = MAX77686_RTC_CONTROL,
132 [REG_RTC_UPDATE0] = MAX77686_RTC_UPDATE0,
133 [REG_WTSR_SMPL_CNTL] = MAX77686_WTSR_SMPL_CNTL,
134 [REG_RTC_SEC] = MAX77686_RTC_SEC,
135 [REG_RTC_MIN] = MAX77686_RTC_MIN,
136 [REG_RTC_HOUR] = MAX77686_RTC_HOUR,
137 [REG_RTC_WEEKDAY] = MAX77686_RTC_WEEKDAY,
138 [REG_RTC_MONTH] = MAX77686_RTC_MONTH,
139 [REG_RTC_YEAR] = MAX77686_RTC_YEAR,
140 [REG_RTC_DATE] = MAX77686_RTC_DATE,
141 [REG_ALARM1_SEC] = MAX77686_ALARM1_SEC,
142 [REG_ALARM1_MIN] = MAX77686_ALARM1_MIN,
143 [REG_ALARM1_HOUR] = MAX77686_ALARM1_HOUR,
144 [REG_ALARM1_WEEKDAY] = MAX77686_ALARM1_WEEKDAY,
145 [REG_ALARM1_MONTH] = MAX77686_ALARM1_MONTH,
146 [REG_ALARM1_YEAR] = MAX77686_ALARM1_YEAR,
147 [REG_ALARM1_DATE] = MAX77686_ALARM1_DATE,
148 [REG_ALARM2_SEC] = MAX77686_ALARM2_SEC,
149 [REG_ALARM2_MIN] = MAX77686_ALARM2_MIN,
150 [REG_ALARM2_HOUR] = MAX77686_ALARM2_HOUR,
151 [REG_ALARM2_WEEKDAY] = MAX77686_ALARM2_WEEKDAY,
152 [REG_ALARM2_MONTH] = MAX77686_ALARM2_MONTH,
153 [REG_ALARM2_YEAR] = MAX77686_ALARM2_YEAR,
154 [REG_ALARM2_DATE] = MAX77686_ALARM2_DATE,
155 [REG_RTC_AE1] = REG_RTC_NONE,
158 static const struct max77686_rtc_driver_data max77686_drv_data = {
162 .alarm_enable_reg = false,
163 .separate_i2c_addr = true,
166 static const unsigned int max77802_map[REG_RTC_END] = {
167 [REG_RTC_CONTROLM] = MAX77802_RTC_CONTROLM,
168 [REG_RTC_CONTROL] = MAX77802_RTC_CONTROL,
169 [REG_RTC_UPDATE0] = MAX77802_RTC_UPDATE0,
170 [REG_WTSR_SMPL_CNTL] = MAX77802_WTSR_SMPL_CNTL,
171 [REG_RTC_SEC] = MAX77802_RTC_SEC,
172 [REG_RTC_MIN] = MAX77802_RTC_MIN,
173 [REG_RTC_HOUR] = MAX77802_RTC_HOUR,
174 [REG_RTC_WEEKDAY] = MAX77802_RTC_WEEKDAY,
175 [REG_RTC_MONTH] = MAX77802_RTC_MONTH,
176 [REG_RTC_YEAR] = MAX77802_RTC_YEAR,
177 [REG_RTC_DATE] = MAX77802_RTC_DATE,
178 [REG_ALARM1_SEC] = MAX77802_ALARM1_SEC,
179 [REG_ALARM1_MIN] = MAX77802_ALARM1_MIN,
180 [REG_ALARM1_HOUR] = MAX77802_ALARM1_HOUR,
181 [REG_ALARM1_WEEKDAY] = MAX77802_ALARM1_WEEKDAY,
182 [REG_ALARM1_MONTH] = MAX77802_ALARM1_MONTH,
183 [REG_ALARM1_YEAR] = MAX77802_ALARM1_YEAR,
184 [REG_ALARM1_DATE] = MAX77802_ALARM1_DATE,
185 [REG_ALARM2_SEC] = MAX77802_ALARM2_SEC,
186 [REG_ALARM2_MIN] = MAX77802_ALARM2_MIN,
187 [REG_ALARM2_HOUR] = MAX77802_ALARM2_HOUR,
188 [REG_ALARM2_WEEKDAY] = MAX77802_ALARM2_WEEKDAY,
189 [REG_ALARM2_MONTH] = MAX77802_ALARM2_MONTH,
190 [REG_ALARM2_YEAR] = MAX77802_ALARM2_YEAR,
191 [REG_ALARM2_DATE] = MAX77802_ALARM2_DATE,
192 [REG_RTC_AE1] = MAX77802_RTC_AE1,
195 static const struct max77686_rtc_driver_data max77802_drv_data = {
199 .alarm_enable_reg = true,
200 .separate_i2c_addr = false,
203 static void max77686_rtc_data_to_tm(u8 *data, struct rtc_time *tm,
204 struct max77686_rtc_info *info)
206 u8 mask = info->drv_data->mask;
208 tm->tm_sec = data[RTC_SEC] & mask;
209 tm->tm_min = data[RTC_MIN] & mask;
210 if (info->rtc_24hr_mode)
211 tm->tm_hour = data[RTC_HOUR] & 0x1f;
213 tm->tm_hour = data[RTC_HOUR] & 0x0f;
214 if (data[RTC_HOUR] & HOUR_PM_MASK)
218 /* Only a single bit is set in data[], so fls() would be equivalent */
219 tm->tm_wday = ffs(data[RTC_WEEKDAY] & mask) - 1;
220 tm->tm_mday = data[RTC_DATE] & 0x1f;
221 tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1;
222 tm->tm_year = data[RTC_YEAR] & mask;
227 * MAX77686 uses 1 bit from sec/min/hour/etc RTC registers and the
228 * year values are just 0..99 so add 100 to support up to 2099.
230 if (!info->drv_data->alarm_enable_reg)
234 static int max77686_rtc_tm_to_data(struct rtc_time *tm, u8 *data,
235 struct max77686_rtc_info *info)
237 data[RTC_SEC] = tm->tm_sec;
238 data[RTC_MIN] = tm->tm_min;
239 data[RTC_HOUR] = tm->tm_hour;
240 data[RTC_WEEKDAY] = 1 << tm->tm_wday;
241 data[RTC_DATE] = tm->tm_mday;
242 data[RTC_MONTH] = tm->tm_mon + 1;
244 if (info->drv_data->alarm_enable_reg) {
245 data[RTC_YEAR] = tm->tm_year;
249 data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0;
251 if (tm->tm_year < 100) {
252 pr_warn("RTC cannot handle the year %d. Assume it's 2000.\n",
260 static int max77686_rtc_update(struct max77686_rtc_info *info,
261 enum MAX77686_RTC_OP op)
265 unsigned long delay = info->drv_data->delay;
267 if (op == MAX77686_RTC_WRITE)
268 data = 1 << RTC_UDR_SHIFT;
270 data = 1 << RTC_RBUDR_SHIFT;
272 ret = regmap_update_bits(info->max77686->rtc_regmap,
273 info->drv_data->map[REG_RTC_UPDATE0],
276 dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n",
277 __func__, ret, data);
279 /* Minimum delay required before RTC update. */
280 usleep_range(delay, delay * 2);
286 static int max77686_rtc_read_time(struct device *dev, struct rtc_time *tm)
288 struct max77686_rtc_info *info = dev_get_drvdata(dev);
289 u8 data[RTC_NR_TIME];
292 mutex_lock(&info->lock);
294 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
298 ret = regmap_bulk_read(info->max77686->rtc_regmap,
299 info->drv_data->map[REG_RTC_SEC],
300 data, ARRAY_SIZE(data));
302 dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, ret);
306 max77686_rtc_data_to_tm(data, tm, info);
308 ret = rtc_valid_tm(tm);
311 mutex_unlock(&info->lock);
315 static int max77686_rtc_set_time(struct device *dev, struct rtc_time *tm)
317 struct max77686_rtc_info *info = dev_get_drvdata(dev);
318 u8 data[RTC_NR_TIME];
321 ret = max77686_rtc_tm_to_data(tm, data, info);
325 mutex_lock(&info->lock);
327 ret = regmap_bulk_write(info->max77686->rtc_regmap,
328 info->drv_data->map[REG_RTC_SEC],
329 data, ARRAY_SIZE(data));
331 dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__,
336 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
339 mutex_unlock(&info->lock);
343 static int max77686_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
345 struct max77686_rtc_info *info = dev_get_drvdata(dev);
346 u8 data[RTC_NR_TIME];
348 const unsigned int *map = info->drv_data->map;
351 mutex_lock(&info->lock);
353 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
357 ret = regmap_bulk_read(info->max77686->rtc_regmap,
358 map[REG_ALARM1_SEC], data, ARRAY_SIZE(data));
360 dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n",
361 __func__, __LINE__, ret);
365 max77686_rtc_data_to_tm(data, &alrm->time, info);
369 if (info->drv_data->alarm_enable_reg) {
370 if (map[REG_RTC_AE1] == REG_RTC_NONE) {
373 "alarm enable register not set(%d)\n", ret);
377 ret = regmap_read(info->max77686->regmap,
378 map[REG_RTC_AE1], &val);
381 "fail to read alarm enable(%d)\n", ret);
388 for (i = 0; i < ARRAY_SIZE(data); i++) {
389 if (data[i] & ALARM_ENABLE_MASK) {
397 ret = regmap_read(info->max77686->regmap, MAX77686_REG_STATUS2, &val);
399 dev_err(info->dev, "%s:%d fail to read status2 reg(%d)\n",
400 __func__, __LINE__, ret);
404 if (val & (1 << 4)) /* RTCA1 */
408 mutex_unlock(&info->lock);
412 static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)
414 u8 data[RTC_NR_TIME];
417 const unsigned int *map = info->drv_data->map;
419 if (!mutex_is_locked(&info->lock))
420 dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
422 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
426 if (info->drv_data->alarm_enable_reg) {
427 if (map[REG_RTC_AE1] == REG_RTC_NONE) {
430 "alarm enable register not set(%d)\n", ret);
434 ret = regmap_write(info->max77686->regmap, map[REG_RTC_AE1], 0);
436 ret = regmap_bulk_read(info->max77686->rtc_regmap,
437 map[REG_ALARM1_SEC], data,
440 dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
445 max77686_rtc_data_to_tm(data, &tm, info);
447 for (i = 0; i < ARRAY_SIZE(data); i++)
448 data[i] &= ~ALARM_ENABLE_MASK;
450 ret = regmap_bulk_write(info->max77686->rtc_regmap,
451 map[REG_ALARM1_SEC], data,
456 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
461 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
466 static int max77686_rtc_start_alarm(struct max77686_rtc_info *info)
468 u8 data[RTC_NR_TIME];
471 const unsigned int *map = info->drv_data->map;
473 if (!mutex_is_locked(&info->lock))
474 dev_warn(info->dev, "%s: should have mutex locked\n", __func__);
476 ret = max77686_rtc_update(info, MAX77686_RTC_READ);
480 if (info->drv_data->alarm_enable_reg) {
481 ret = regmap_write(info->max77686->regmap, map[REG_RTC_AE1],
482 MAX77802_ALARM_ENABLE_VALUE);
484 ret = regmap_bulk_read(info->max77686->rtc_regmap,
485 map[REG_ALARM1_SEC], data,
488 dev_err(info->dev, "%s: fail to read alarm reg(%d)\n",
493 max77686_rtc_data_to_tm(data, &tm, info);
495 data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT);
496 data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT);
497 data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT);
498 data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK;
499 if (data[RTC_MONTH] & 0xf)
500 data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT);
501 if (data[RTC_YEAR] & info->drv_data->mask)
502 data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT);
503 if (data[RTC_DATE] & 0x1f)
504 data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT);
506 ret = regmap_bulk_write(info->max77686->rtc_regmap,
507 map[REG_ALARM1_SEC], data,
512 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
517 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
522 static int max77686_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
524 struct max77686_rtc_info *info = dev_get_drvdata(dev);
525 u8 data[RTC_NR_TIME];
528 ret = max77686_rtc_tm_to_data(&alrm->time, data, info);
532 mutex_lock(&info->lock);
534 ret = max77686_rtc_stop_alarm(info);
538 ret = regmap_bulk_write(info->max77686->rtc_regmap,
539 info->drv_data->map[REG_ALARM1_SEC],
540 data, ARRAY_SIZE(data));
543 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n",
548 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
553 ret = max77686_rtc_start_alarm(info);
555 mutex_unlock(&info->lock);
559 static int max77686_rtc_alarm_irq_enable(struct device *dev,
560 unsigned int enabled)
562 struct max77686_rtc_info *info = dev_get_drvdata(dev);
565 mutex_lock(&info->lock);
567 ret = max77686_rtc_start_alarm(info);
569 ret = max77686_rtc_stop_alarm(info);
570 mutex_unlock(&info->lock);
575 static irqreturn_t max77686_rtc_alarm_irq(int irq, void *data)
577 struct max77686_rtc_info *info = data;
579 dev_info(info->dev, "%s:irq(%d)\n", __func__, irq);
581 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
586 static const struct rtc_class_ops max77686_rtc_ops = {
587 .read_time = max77686_rtc_read_time,
588 .set_time = max77686_rtc_set_time,
589 .read_alarm = max77686_rtc_read_alarm,
590 .set_alarm = max77686_rtc_set_alarm,
591 .alarm_irq_enable = max77686_rtc_alarm_irq_enable,
594 static int max77686_rtc_init_reg(struct max77686_rtc_info *info)
599 /* Set RTC control register : Binary mode, 24hour mdoe */
600 data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
601 data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
603 info->rtc_24hr_mode = 1;
605 ret = regmap_bulk_write(info->max77686->rtc_regmap,
606 info->drv_data->map[REG_RTC_CONTROLM],
607 data, ARRAY_SIZE(data));
609 dev_err(info->dev, "%s: fail to write controlm reg(%d)\n",
614 ret = max77686_rtc_update(info, MAX77686_RTC_WRITE);
618 static int max77686_rtc_probe(struct platform_device *pdev)
620 struct max77686_dev *max77686 = dev_get_drvdata(pdev->dev.parent);
621 struct max77686_rtc_info *info;
622 const struct platform_device_id *id = platform_get_device_id(pdev);
625 dev_info(&pdev->dev, "%s\n", __func__);
627 info = devm_kzalloc(&pdev->dev, sizeof(struct max77686_rtc_info),
632 mutex_init(&info->lock);
633 info->dev = &pdev->dev;
634 info->max77686 = max77686;
635 info->rtc = max77686->rtc;
636 info->drv_data = (const struct max77686_rtc_driver_data *)
639 if (!info->drv_data->separate_i2c_addr)
640 info->max77686->rtc_regmap = info->max77686->regmap;
642 platform_set_drvdata(pdev, info);
644 ret = max77686_rtc_init_reg(info);
647 dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret);
651 device_init_wakeup(&pdev->dev, 1);
653 info->rtc_dev = devm_rtc_device_register(&pdev->dev, id->name,
654 &max77686_rtc_ops, THIS_MODULE);
656 if (IS_ERR(info->rtc_dev)) {
657 ret = PTR_ERR(info->rtc_dev);
658 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
664 if (!max77686->rtc_irq_data) {
666 dev_err(&pdev->dev, "%s: no RTC regmap IRQ chip\n", __func__);
670 info->virq = regmap_irq_get_virq(max77686->rtc_irq_data,
671 MAX77686_RTCIRQ_RTCA1);
677 ret = devm_request_threaded_irq(&pdev->dev, info->virq, NULL,
678 max77686_rtc_alarm_irq, 0, "rtc-alarm1", info);
680 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
687 #ifdef CONFIG_PM_SLEEP
688 static int max77686_rtc_suspend(struct device *dev)
690 if (device_may_wakeup(dev)) {
691 struct max77686_rtc_info *info = dev_get_drvdata(dev);
693 return enable_irq_wake(info->virq);
699 static int max77686_rtc_resume(struct device *dev)
701 if (device_may_wakeup(dev)) {
702 struct max77686_rtc_info *info = dev_get_drvdata(dev);
704 return disable_irq_wake(info->virq);
711 static SIMPLE_DEV_PM_OPS(max77686_rtc_pm_ops,
712 max77686_rtc_suspend, max77686_rtc_resume);
714 static const struct platform_device_id rtc_id[] = {
715 { "max77686-rtc", .driver_data = (kernel_ulong_t)&max77686_drv_data, },
716 { "max77802-rtc", .driver_data = (kernel_ulong_t)&max77802_drv_data, },
719 MODULE_DEVICE_TABLE(platform, rtc_id);
721 static struct platform_driver max77686_rtc_driver = {
723 .name = "max77686-rtc",
724 .pm = &max77686_rtc_pm_ops,
726 .probe = max77686_rtc_probe,
730 module_platform_driver(max77686_rtc_driver);
732 MODULE_DESCRIPTION("Maxim MAX77686 RTC driver");
733 MODULE_AUTHOR("Chiwoong Byun <woong.byun@samsung.com>");
734 MODULE_LICENSE("GPL");